RISE Jennifer Nocerino: Wonderful thanks so much my name is Jennifer know serena and i'm with the geological society of America, and this is just a reminder that GSA has a rise code.
RISE Jennifer Nocerino: which is respectful inclusive scientific events, and so we ask you to show respect to be inclusive and to act responsibly, thank you.
Todd LaMaskin (he/him): Thank you Jennifer.
Todd LaMaskin (he/him): So welcome everybody, my name is Todd laskin and along with Robbie morrow and Dave blake we are coordinating this session here this afternoon, this is session.
Todd LaMaskin (he/him): D3 southern appalachian and analogous terrains number two and it's scheduled to run from 230 to 630 today and so it's my pleasure to introduce our first talk.
Todd LaMaskin (he/him): Patrick finnerty and others patrick's talk is titled hard to judge your rock by its cover new perspectives on the eastern rally terrain in the north Carolina Eastern Piedmont so Patrick if you want to share your screen.
Patrick Finnerty - VDGMR: or give this a shot.
Patrick Finnerty - VDGMR: Can everyone see that.
Todd LaMaskin (he/him): We can see it, and we can hear you.
Patrick Finnerty - VDGMR: Perfect alright, so thank you for joining me today as I talk about our new perspectives here North Carolina Eastern Piedmont, specifically the eastern rally trend.
Patrick Finnerty - VDGMR: We look at the appalachian origin as a whole.
Patrick Finnerty - VDGMR: We can see that you have your attention around and a variety of different domains, including the Piedmont domain huge one domain, along with these paragon one and domains on the southern appalachian origin carolinian.
Patrick Finnerty - VDGMR: has generally been the focus of thoughts and northern appalachian origin, we have these other paragon wanted domains, such as candy area.
Patrick Finnerty - VDGMR: And apollonian the zoom in here to Virginia North Carolina gun from west to east, you had your wrench and around Piedmont domain in this neoproterozoic cambrian carolinian.
Patrick Finnerty - VDGMR: On across the the Western most extent of the eastern Piedmont fault system to the north, you have the the goose island domain and then.
Patrick Finnerty - VDGMR: These other possible domain so.
Patrick Finnerty - VDGMR: zooming into that area for more detail.
Patrick Finnerty - VDGMR: see that the Carolina and Charlotte rains are these typical carolinian terrains 633 or 528 ma and the usual and domain, you had the state farm nice down, which is considered to be laurentian have a luncheon affinity 1.1 1.0 billion years old.
Patrick Finnerty - VDGMR: Along with the maidens Nice, which is this early middle devonian intrusive.
Patrick Finnerty - VDGMR: sweet.
Patrick Finnerty - VDGMR: Then across the net push creek falls in part of the actual strand of the Houston Piedmont false system we have the Western rally terrain.
Patrick Finnerty - VDGMR: And there's been a handful of published ages, ranging from 562 424 on the rally nice though i'm not really going to get into that at all.
Patrick Finnerty - VDGMR: But across the lake Gordon cheers on which separates the the Western rally train from euston rally during her and teach service to your chronological data set.
Patrick Finnerty - VDGMR: And he reported these early devonian crystallization and maximum deposition agents and that's the you know the thought processes.
Patrick Finnerty - VDGMR: Across the eastern Piedmont fall system.
Patrick Finnerty - VDGMR: That the eastern rally train really.
Patrick Finnerty - VDGMR: Does not correlate well with carolinian so maybe part of a different.
Patrick Finnerty - VDGMR: domain, so if we zoom in here to focus in on eastern rally trend.
Patrick Finnerty - VDGMR: My roadmap project focus on the Northern portion of the making quadrangle and I was generally testing for the continuation of mythology from previous mapping and.
Patrick Finnerty - VDGMR: Also testing for the extent of high strain over print related to make in folsom another textural stream of the Houston Piedmont full system.
Patrick Finnerty - VDGMR: But if we look at this generalized quad map, we can see that there's three main with allergies, you have your grant boyd Nice, which is, which is your Liberia Nice in these new Socratic music critic biotech a nicer file type form one Nice is that's your park town and possum quarter Nice.
Patrick Finnerty - VDGMR: Then there is a semi bearing muscovite schist or just your Muscovites just with variable amounts of by tight and chloride content as well that's the the milgram shifts So these are the four.
Patrick Finnerty - VDGMR: main with the Dems that i'll be focusing on for this whole.
Patrick Finnerty - VDGMR: We started looking at the park time Nice, this is one of the units that brandon peach dated and he had a for 10am a crystallization huge mark Carter with the usgs helped us attain geochemical analyses park Tom possum quarter and Liberia.
Patrick Finnerty - VDGMR: plotted out the park town nice ended up coming out as a day side, you can see that it's fairly find Crystal and.
Patrick Finnerty - VDGMR: has an abundance of Horn blind and by outside.
Patrick Finnerty - VDGMR: The possum quarter nice I dated this sample i'll get into that in a little bit, but for three and a crystallization age, and this is a corporate ecologically Rock in the geo chemical signature indicated that it's a modern directly.
Patrick Finnerty - VDGMR: Through the mill branch just again it's a pretty.
Patrick Finnerty - VDGMR: has some wide variety to it but generally it's this so my bearing muscular like shifts and C and D here the slender white prism those are your So when I portrait bless occasionally and then section you'll see core toy.
Patrick Finnerty - VDGMR: Which is interpreted to be a retrograde over print of silver line.
Patrick Finnerty - VDGMR: mil branches also commonly have these fell sick stringers or fell sick domains.
Patrick Finnerty - VDGMR: And that's an important observation.
Patrick Finnerty - VDGMR: For for later in this discussion, lastly, we have the Liberia Nice, and this is your corporate classic K felts bar kinetic nicer grant toy nice geochemical analyses indicate that it's a.
Patrick Finnerty - VDGMR: Matsu genetic nice, but you know the composition may vary throughout the Trans pretty widespread unit.
Patrick Finnerty - VDGMR: It can range from protocol and etiquette as you see here a C and E to.
Patrick Finnerty - VDGMR: When it's caught up in the in the making folder on the high street over print see significant grain size reduction and it's ultra my limited varieties.
Patrick Finnerty - VDGMR: Moving on to our structural fat fabric elements we have fairly consistent across the.
Patrick Finnerty - VDGMR: The field area compositional layering which may just be a regional metamorphic over Prem but also throughout the area we had these.
Patrick Finnerty - VDGMR: textural sheer bands your as one see want as long with actual kinematic indicators such as this Mike a fish here.
Patrick Finnerty - VDGMR: And photograph D.
Patrick Finnerty - VDGMR: And within the making fault zone your.
Patrick Finnerty - VDGMR: Most highly strained rocks you'll even see your sc prime fabric.
Patrick Finnerty - VDGMR: there's also a two fold generations, we have our ISO final exoplanets affiliation at one fold that also may get refolded by or more operates.
Patrick Finnerty - VDGMR: gentle of the time F two folds and move on to the last slide here for that you can see the variation in these two this younger full generation.
Patrick Finnerty - VDGMR: To supplement the geologic mapping I conducted le ic K, Ms to chronology with the.
Patrick Finnerty - VDGMR: ladder University of South Carolina with the, with the help of Dr.
Patrick Finnerty - VDGMR: David our bow and I collected for samples that.
Patrick Finnerty - VDGMR: From previously math areas and generally major units, so the posse quarter Nice, as I mentioned before this garnet by the tight schist.
Patrick Finnerty - VDGMR: Someone I bearing know branches and our Liberia Monza kinetic nice person look at the possum quarter Nice.
Patrick Finnerty - VDGMR: you'll get a unit modal age distribution common and or what you might expect, for dignitas proto with.
Patrick Finnerty - VDGMR: And with 80 to 105 concordance I calculated a weighted mean age of 43 am a.
Patrick Finnerty - VDGMR: similar to the park town, Nice and it's early devonian crystallization age.
Patrick Finnerty - VDGMR: And just to make a quick note, if you look at the the zircons here they typically maintained a pretty strong.
Patrick Finnerty - VDGMR: original morphology if they were an eagle and you don't really see many, many areas of.
Patrick Finnerty - VDGMR: Where there's metamorphic rims or any significant alteration i'll show you a few examples later on.
Patrick Finnerty - VDGMR: to compare.
Patrick Finnerty - VDGMR: Be garner rich muscovite by location or this garnet shift you'll get a much different distribution multimodal.
Patrick Finnerty - VDGMR: Something we would expect in a sedimentary rock.
Patrick Finnerty - VDGMR: And there's generally two major age ranges here in the sample that's 1500 to 1000 them a and then a younger age range of 500 to about 400 and.
Patrick Finnerty - VDGMR: And if we look at the zircons here there's a lot more variety than what we saw and.
Patrick Finnerty - VDGMR: The possum quarter Nice, and you can actually see some metamorphic rims and some some darker darker core rim relationships, but so considering this to be a medicine momentary rock I.
Patrick Finnerty - VDGMR: Will 50 to 105 concordance I.
Patrick Finnerty - VDGMR: calculated the maximum deposition age of those youngest acceptable Greens to be 414.
Patrick Finnerty - VDGMR: And then.
Patrick Finnerty - VDGMR: And for the milgram shift, similarly to the garden five patients there's this multi modal age distribution.
Patrick Finnerty - VDGMR: Similar similar age ranges where you do have this older 1500 to even 800 and they circle age ranges and then this younger P 500 to.
Patrick Finnerty - VDGMR: 400 and then, if you notice there is this this younger 360 ma age range, if we take a look at the desert cons are yielded from the sample.
Patrick Finnerty - VDGMR: We can see that there's many that that appear resort around it in appearance and others that have these dark cores that.
Patrick Finnerty - VDGMR: don't don't look like a typical zero con core So those are interpreted to be resolved mathematics their cons and potentially.
Patrick Finnerty - VDGMR: partially or completely metamorphic Lee reset when you're generating the high temperature so midnight.
Patrick Finnerty - VDGMR: And those those resort and Meta mixer cons are associated with these younger ages and i'll i'll get into that more later on.
Patrick Finnerty - VDGMR: But using the same method to calculate maximum depth positional age.
Patrick Finnerty - VDGMR: I got 413.
Patrick Finnerty - VDGMR: me so this early devonian maximum depth additional ages and crystallization ages seems to be prominent here in the in the eastern knowledge and.
Patrick Finnerty - VDGMR: Lastly, we have the Liberian Nice which.
Patrick Finnerty - VDGMR: Definitely throw us a curveball here, because you can see that it's it looks like a Meta grant toy proto Milan in a Meta granted.
Patrick Finnerty - VDGMR: But a yield of this multi modal age distribution.
Patrick Finnerty - VDGMR: So that was that was the first surprise and when we're really looking at these are cons and.
Patrick Finnerty - VDGMR: Under a feminine essence, you can see that we have these.
Patrick Finnerty - VDGMR: zircons that didn't women asset all their their their so he drill though to you here drill they don't look like these resorts mathematic Sir Con grains.
Patrick Finnerty - VDGMR: And given given their appearance I interpreted them to be metamorphic Lee crystallize zircons.
Patrick Finnerty - VDGMR: So.
Patrick Finnerty - VDGMR: far, we have a genetic rock that has a multimodal age distribution well first we go back to the mapping and Liberia Nice was consistently in contact with the Melbourne shifts versus some of the other units.
Patrick Finnerty - VDGMR: In the area like I mentioned before the mill branches often has these Celtic stringers or fell sick domains of similar composition, to the mill branch shifts.
Patrick Finnerty - VDGMR: So we started looking at the Foreign uranium ratios, as I mentioned, and that makes their cons in the milgram schist correspond to these low less than 0.1.
Patrick Finnerty - VDGMR: During uranium ratios to maybe a indicator of metamorphic reset and to to certain extent, at the very least.
Patrick Finnerty - VDGMR: And then, with the Liberia sample the cl dark metamorphic Lee crystallized certain grains all.
Patrick Finnerty - VDGMR: Were were younger what these younger ages and calculating the mean way to the way to mean age I got a 331 ma.
Patrick Finnerty - VDGMR: Age.
Patrick Finnerty - VDGMR: considering what would happen if you melted the male brain shift and re crystallized it, you would get a similar composition to Liberia Nice.
Patrick Finnerty - VDGMR: So our hypothesis right now is that there's in situ melting are being met ization of the mill branch schist that then crystallized the Liberian Nice and those metamorphic zircons in the Liberian Nice.
Patrick Finnerty - VDGMR: And that also is an attempt to explain why there's a multicultural age, distribution and Monza frenetic rock.
Patrick Finnerty - VDGMR: Also, looking back at the generalized NAB the eastern rally terrain in the relationship between the mill branch just in this Liberia nice even looks magnetic at the map scale.
Patrick Finnerty - VDGMR: So plotting these mathematics and metamorphic Lee crystallized their cons on Korea.
Patrick Finnerty - VDGMR: can see that, from the youngest accepted grains and mill branches, to the metal mixer cons to the metaphorically crystallized their guns, there appears to be some potentially a metamorphic event starting around CIRCA 3D ma and continuing through at least 315 and they.
Patrick Finnerty - VDGMR: And so, if I bring you back to the the fabric elements that we had these different strain faces that we have from mapping to Liberia nice being the youngest unit contains or has been over printed records, all of these different fabric elements.
Patrick Finnerty - VDGMR: So really there's a loose hypothesis right now that there's potentially.
Patrick Finnerty - VDGMR: Neo acadian high temperature metamorphic ISM possibly some defamation, but generating the Superman I met him horrifically resetting some of the zircons in the mail branch shifts and that continued into the hell again Ian.
Patrick Finnerty - VDGMR: where he began to melt mill branches and crystallize the the Liberia.
Patrick Finnerty - VDGMR: Not as.
Patrick Finnerty - VDGMR: I know, definitely for future work to have Mon, as I dating and further geographical analyses could really help.
Patrick Finnerty - VDGMR: Either rework or build upon this hypothesis.
Patrick Finnerty - VDGMR: So, starting from the beginning.
Patrick Finnerty - VDGMR: it's clear that the these around train probably formed in some sort of early devonian island our base in the generated your calc one Bolton ISM and magnetism along with your deposition.
Patrick Finnerty - VDGMR: Of variety of potential sources.
Patrick Finnerty - VDGMR: Moving on, you have a potential again question mark around neo acadian metamorphic over Prem but then ultimately given our youngest unit being surface 330 ma allegheny and transgression likely over printed.
Patrick Finnerty - VDGMR: These units and generated the majority of the fabric elements we witness in the eastern rally train.
Patrick Finnerty - VDGMR: So, going back to this figure here.
Patrick Finnerty - VDGMR: We can say that the the dates in the eastern rally train not correlate well at all, and the Carolina Carolina terrains here across the notebooks creek folsom.
Patrick Finnerty - VDGMR: However, given the early devonian to the middle of the billion ages in the maintenance Nice.
Patrick Finnerty - VDGMR: There could be a possible correlation there that needs needs further testing.
Patrick Finnerty - VDGMR: And there has been, since by my efforts there jack nolan.
Patrick Finnerty - VDGMR: produced even more ages from think four or five different units and the next talk will really kind of dive more into the significance of this desert con work we've been doing since spring and peach started.
Patrick Finnerty - VDGMR: So i'd like to acknowledge everyone, and all these organizations involved in this in this research and the list could go on and on, but Thank you everyone.
Patrick Finnerty - VDGMR: So with that i'll open it up to any questions.
Dave Blake: Are there any questions, thank you, Patrick your thesis advisor would be proud of you.
Robert Morrow: And there's got a question or three you want to go to ask Patrick real quickly.
Arthur Merschat: hey Patrick that's awesome talk really interesting stuff really exciting course just hearing all in yeah sounds yes, the such as similarities to parts of the rp month to ask where train.
Arthur Merschat: what's the nature, the Western boundary to the Carolina turn I know you showed us a big sexual assault sexual strikes at fault is it dipping underneath parts of the Carolina trainers and also dipping back to the south east there.
Patrick Finnerty - VDGMR: Well i'm not sure I can I can answer that there will be.
Patrick Finnerty - VDGMR: Back Dr play will be given a talk later on talking more about the significance of the eastern Piedmont fall system.
Patrick Finnerty - VDGMR: up from.
Patrick Finnerty - VDGMR: I guess you're asking.
Patrick Finnerty - VDGMR: in regards to being a suitor or more.
Arthur Merschat: Just even just like a cross section real quickly right across it is, it is it you know with most of the rocks be verging.
Arthur Merschat: With the roxy and also since it's there's a lot actual sharing, but is it probably trans professional is summit coming actually still because we'd be verging back out to the east as well in the transportation, or is it all.
Arthur Merschat: virgin Northwest with with the transgression in the actual Shirin just is it over could it be overlying the Carolina trainer underlying it and coming out.
Patrick Finnerty - VDGMR: that's a that's a good question.
Patrick Finnerty - VDGMR: Maybe we can talk about the lyric I couldn't get anything solid right now for an answer.
Arthur Merschat: really excellent talking good mapping to Patrick.
Patrick Finnerty - VDGMR: Thank you.
Robert Morrow: So if.
Robert Morrow: We have any more questions for.
Robert Morrow: Patrick.
Robert Morrow: We can ask them during the break.
Robert Morrow: we'll move on to our next talk Todd you want me to introduce you.
sure.
Robert Morrow: So our next talk is going to be by title masking.
Robert Morrow: Going by jack nolan Patrick finnerty brandon peach.
Robert Morrow: Day blake and.
Robert Morrow: yeah he's gonna be talking about zero con uranium lead Jia chronology of the eastern raleigh terrain in the north Carolina Eastern people.
Todd LaMaskin (he/him): Is my screen shared and full size.
Robert Morrow: We don't see it in presentation mode yet.
Todd LaMaskin (he/him): You see it, a non presentation, but.
Dave Blake: We just see all the people right now.
Todd LaMaskin (he/him): let's try it again.
Todd LaMaskin (he/him): Now.
Dave Blake: Yes.
Todd LaMaskin (he/him): Good to go.
You Sir.
Todd LaMaskin (he/him): And can you see my pointer as well.
Dave Blake: Yes, sir.
Todd LaMaskin (he/him): Great.
Todd LaMaskin (he/him): Alright, so just to give again some context to the talk, when we look out at the broader appalachian origin.
Todd LaMaskin (he/him): It consists of a number of different realms These include in blue the laurentian realm and in green the APP and and or Perry laurentian realm and then I want to draw your attention to the paragon dwan and realm.
Todd LaMaskin (he/him): The paragon dwan and realm consists of arteries that are believed to have originated along the margin of gondwana during late neoproterozoic an early paleozoic time and.
Todd LaMaskin (he/him): The paragon dawn and terrains are composed of numerous second order domains, these include carolinians shown here, and this orange again derrida abalone and.
Todd LaMaskin (he/him): I also want to note the somewhat enigmatic Gucci island domain that's shown here.
Todd LaMaskin (he/him): So carolinian is one of these paragon Guan and terrains it consists of several paragon to on it turns that were brought together and lake neoproterozoic protozoa time.
Todd LaMaskin (he/him): And it contains rocks as old as 672 ma and art magnetism is believed to have continued into early cambrian time and so here's a map from hibbert and others.
Todd LaMaskin (he/him): Have carolinian showing you a variety of the sub terrains that make up carolinian and I want you to notice.
Todd LaMaskin (he/him): over to the East, we have what they call other terrains of carolinian, and so I also want to note the presence of this somewhat enigmatic Gucci island terrain so i'm now going to zoom in on this map right here and we're going to talk about these other terrains.
Todd LaMaskin (he/him): So then zooming in here, we have all these other terrains the CT Charlotte terrain, is part of carolinian and the remainder here are the other terrains so.
Todd LaMaskin (he/him): These consists of green schist faces to range, such as the spring hook, and the roanoke rapids terrain.
Todd LaMaskin (he/him): As well as enfeebled like faces terrains like the falls lake and crabtree terrain, as well as the Western rollie terrain down here.
Todd LaMaskin (he/him): And then, on the other side of these pennsylvanian permian grant a toy bodies, we have the subject to today's talk the eastern.
Todd LaMaskin (he/him): raleigh terrain also want to know if the presence of the triplet terrain and then the presence of the dinwiddie terrain, which is going to be the subject of mark carter's.
Todd LaMaskin (he/him): talk a little bit later today, and all of these other terrains are all separated by textural strands of the eastern Piedmont fault system.
Todd LaMaskin (he/him): So here, then, is are the other terrains and here is the goose island terrain, and so the rocky terrain is traditionally considered part of carolinian here it is on hubert's 2006 map.
Todd LaMaskin (he/him): mapped as a unit 15 called out as a neoproterozoic and Cambridge and age rocks.
Todd LaMaskin (he/him): But it has also been considered potentially correlative two rocks of the Gucci blunter and here's hatches tectonic map and you can see here they actually calls it, the rally googling terrain now this link terrain has a long history.
Todd LaMaskin (he/him): It includes i'm a 1000 ma state farm Nice, as well as the montpelier north of sight in treated by neoproterozoic granted towards as well as the 552 ma Sabbath amphibian light which shows growth of metamorphic.
Todd LaMaskin (he/him): As well as lead loss ages that Center around for 15 to 400 and then Brent owens has given us even just recently a tremendous amount of information on the maidens Nice.
Todd LaMaskin (he/him): Recognizing the presence of devonian rocks the presence of 360 ma metamorphic and at last year's cancelled southeastern GSA section meeting his abstract suggests the presence of 430 to 818 hundred ma as well as several archean grains and then plausible Max deposition all ages.
Todd LaMaskin (he/him): In the range of 404 50 ma as well as Mon, as it metamorphic ages of 373 and so there's a little bit of background about the terrain.
Todd LaMaskin (he/him): So what i'm going to do today is zoom in on the same area that Patrick just showed you.
Todd LaMaskin (he/him): And i'm going to present a compilation of all of our reserve con uranium legit chronology that we've gotten to date, as well as present to you some brand new hot off the presses it tim's data that i'm working with Dave blake and Jim Crowley at Boise state.
Todd LaMaskin (he/him): isotope G chronology laboratory to generate.
Todd LaMaskin (he/him): So this is a map that i'll come back to several times it's very similar to what Patrick just showed you and simply a list of all of the lymphoedema units.
Todd LaMaskin (he/him): That i'm going to present to their account or to present Sir Con uranium lead data from so let's get into what my data reduction strategies are.
Todd LaMaskin (he/him): So, first of all our crossover point 468276 ages is 900 ma i'm excluding all grains that have greater than 2.5% contribution from common lead.
Todd LaMaskin (he/him): And i'm excluding grains with greater than 5% six eight error, greater than 10% seven six error and then perhaps most importantly, what i'm reporting today is ages.
Todd LaMaskin (he/him): That are only within the range of 82 105 concordance.
Todd LaMaskin (he/him): Now what we're going to learn is that assessment of metamorphic versus igneous ages can be quite difficult here, and so the common conception, is that story of uranium less than point one means metamorphic.
Todd LaMaskin (he/him): In actuality it's been shown that metamorphic or con can range from very, very low, all the way up to 10 accomplish big compilation showed that the median value is point for for.
Todd LaMaskin (he/him): igneous or con can range from less than point 01 to 20 with a median value of Point six eight very, very close to that of metamorphosis or con.
Todd LaMaskin (he/him): And in fact coding Kelly suggests that throwing me radium that's grown in the presence of partial melt.
Todd LaMaskin (he/him): May approach that of igneous zircons so our strategy is to plot thorium uranium versus age.
Todd LaMaskin (he/him): and also to create density contour points to look for a break point where we can see generally low versus generally high for him uranium values and then is shown here by.
Todd LaMaskin (he/him): This plot by Spencer, to look for negatively skewed tales that indicate lead loss, as well as plateaus in hd to that might represent true ages.
Todd LaMaskin (he/him): So here on our map we're going to start in the West, this is our vic's borough.
Todd LaMaskin (he/him): Nice sample and so here's a beautiful image cat photo lemon essence, and you can see right away the presence of an igneous core here's a laser shot.
Todd LaMaskin (he/him): And these very, very cl dark rooms, these are very, very low uranium rims In addition we have grains themselves not just rims but cores which are low thorium uranium and they return ages in the range of 355 ma.
Todd LaMaskin (he/him): here's one of those contour plots, this is a urine is a thorium uranium.
Todd LaMaskin (he/him): This line right here is point one this line is point five, and then here's the age, so you can see, we have a clear break in the sample.
Todd LaMaskin (he/him): ages less than 400 ma are low authority of uranium age is greater than that are higher and so these low Thor in uranium ages, give us a weighted mean age of about 353.
Todd LaMaskin (he/him): The remaining ages show a strong peek at 490 and then the majority of our grains cluster between 1,000,000,002 billion years old, with strong peaks at 1.2 billion and about 1.5 billion.
Todd LaMaskin (he/him): So the vics per Nice is a Meta sedimentary rock it's got dominant ages 2.2 1.0 and for 90 and contains evidence for metamorphosis and about 350.
Todd LaMaskin (he/him): This the next one is just a little bit further north north, this is the Soul City nice here we've got both cl dark rooms and cl bright rims and we get one low for him uranium metamorphic grain here at 355.
Todd LaMaskin (he/him): The age distribution is 1.22 point O with a very, very strong peek at 1.2 so the Soul City Nice is also a Meta sedimentary rock dominant ages two to 1.0 evidence for metamorphosis CIRCA 3:35am.
Todd LaMaskin (he/him): Moving on now, the next rock is actually about 55 kilometers north of here, still in a region that's mapped as the eastern raleigh terrain, and this is the Union mill Nice, we have an.
Todd LaMaskin (he/him): For our can coordinate range of 82 one to five, so it's not that many grains, but we have a wide spread of ages our youngest age mode is for 15 ma and you can see here on our density plot.
Todd LaMaskin (he/him): that's in a cluster of ages with higher thorium uranium ratios likely igneous zero con and then the maximum depth positional age of zircons overlapping it to Sigma is roughly 420 and a and then we have evidence at.
Todd LaMaskin (he/him): of low thorium uranium green, so the Union mill Nice is a Meta sedimentary rock it has a maximum deposition of age of about 419 now interestingly.
Todd LaMaskin (he/him): that's with this rather strong concordance filter of 82 105 when you remove that the maximum depth additional age is about 408 and that'll become important in just a SEC.
Todd LaMaskin (he/him): Some other really interesting stuff that comes out is when we have the Union mill Nice is if we bring back in those grains that are loaded with common lead common lead has a seven six ratio up in the point eight range.
Todd LaMaskin (he/him): We can draw a cord through a number of high common lead grains down to another low thorium uranium grain.
Todd LaMaskin (he/him): And this cool this discord suggests that we have a metamorphic event around 344 ma, and these are zircons that are growing during metamorphosis incorporating high amounts of common lead.
Todd LaMaskin (he/him): So the Union and all nice appears to record a metamorphic event about 345 ma and then has led loss ages, or possibly other metamorphic event ages 392 three.
Todd LaMaskin (he/him): And then the other unit that I want to talk about real quickly here in this portion is the garnet by a tight chest so again, we have.
Todd LaMaskin (he/him): An age peek at around 485 with our strong discordance filter we can resolve a maximum deposition of age of 485, and this is the same rock that.
Todd LaMaskin (he/him): Patrick just talked about where he opened up the coordinates filter from 80 to one or five to 52 105 and we have a maximum depth positional age of about 415 you can see here from the density contour plot again age here for him uranium here a breakpoint.
Todd LaMaskin (he/him): In this range right here just past 400 and a higher authority and uranium older than 400 lower thorium uranium.
Todd LaMaskin (he/him): Under that so the garnet by a tight chest as a Meta sedimentary rock deposition the age of 45 but possibly for 14 considering how you approach discordance and lead loss and metamorphic ages 375 and 340.
Todd LaMaskin (he/him): And so, this down here is then all of those units vicksburg to Seoul city Union mill and garnet by a tight all plotted together and i'm plotting them against a paper that came out just last October by that Piper and Chris hepburn.
Todd LaMaskin (he/him): Where what they did was they compiled the titles or con ages from the eastern laurentian margin of the appalachians so these age data reflect.
Todd LaMaskin (he/him): The eastern laurentian margin prior to the arrival of gone dwan and terrains and while the match is not perfect, it does seem to be quite compelling our for at peak they have a 468 peak.
Todd LaMaskin (he/him): Our dominant age mode is 1200 ma whereas there's is a right around a billion, or a little bit older, and so I wonder whether the differences, they have 7500 we have 352 ages.
Todd LaMaskin (he/him): So it definitely deserves a little bit more digging into, but I do believe that it suggests that the source area for these Western units in our field area may include laurentian or Perry laurentian rocks.
Todd LaMaskin (he/him): Okay, so now we're going to move to the eastern portion of our field area and what i'm showing you are our four samples of mill branch schist.
Todd LaMaskin (he/him): These again have a tremendous number of cl dark rims as well as resource rounded textures and these rooms always give ages around 350 to 400 here's for Concordia plots.
Todd LaMaskin (he/him): As well as a probability density plots and then what i've done here is calculate the maximum deposition age from the youngest Greens that are present.
Todd LaMaskin (he/him): So each of these has a peak of anywhere from 410 to 432 of these samples contain a high proportion of ages.
Todd LaMaskin (he/him): 515 to 588 and then all of the samples contain an HP right around a billion, or a little bit older than a billion maximum depth positional ages range from 407249 so this mill branch just is dominated by this for 10 to 430 age with.
Todd LaMaskin (he/him): ages, the maximum depth additional ages of 492407 we've got low throwing uranium rims coming in less than 400 ma down to about 350 and a prominent age mode right around a billion, or a little bit older.
Todd LaMaskin (he/him): And then, finally, we have three samples, which include two samples from the park town, Nice and then the possum quarter Nice which.
Todd LaMaskin (he/him): Patrick just showed you, these are almost all ubiquitously the uni modal there is one old precambrian grain to grains just slightly over than 500 million years in one park town nice sample the others contain only ages in the spread of about 452 younger than 450 getting them.
Todd LaMaskin (he/him): into the range of about 382 350 and so, whether these are igneous crystallization ages, or whether they are maximum deposition of ages.
Todd LaMaskin (he/him): You can calculate an age of about four or five to 407 off of the youngest plateau age within each of these rocks now we've done a little bit of additional work.
Todd LaMaskin (he/him): On one of the part town nice samples, and it shows extremely variable rare earth element chemistry from zero con desert con which suggests that these are met a cemetery rocks with maximum deposition all ages in the range of 407 to 403.
Todd LaMaskin (he/him): So we've got these laser ablation results in a rather tight concordance range that give us ages of 45 to 49, but we also have lots of evidence of metamorphosis in cl dark.
Todd LaMaskin (he/him): zircons and rims longoria Miriam grains so we want to know if these are true crystallization ages, or if they are lead last ages.
Todd LaMaskin (he/him): So we've initiated a project that we're right in the middle of today with Jim Crowley at the Boise state isotope Jia chronology lab and we sent him to samples are 18 park town.
Todd LaMaskin (he/him): And our 18 mill branch to sample and I can report today, some 18 park town samples, and so we did this amazing technique which is laser cutting.
Todd LaMaskin (he/him): CIV tim's, the first thing we did was laser ablation spots on one side of the grains and we popped them out of the park turn them over repossi them and Polish them down on the other side and did laser ablation spots on the other part of the great.
Todd LaMaskin (he/him): Jim then figured out where different age domains were and different cl domains were and use the laser to actually cut.
Todd LaMaskin (he/him): These grains into little fragments so here's the grain after it's been cut and here it is sideways and this little fragment is what we did the laser ablation excuse me, the CIV tim's on.
Todd LaMaskin (he/him): And so over 30 grains from the sample 18 park town showing you the myriad data that we got.
Todd LaMaskin (he/him): From all these different grains and, ultimately, we chose five grains on the the basis of their size and their morphology.
Todd LaMaskin (he/him): And the ages range from 397 ma at the youngest to 408 m a at the oldest and so these are the fragments that we then did CIV tim's on.
Todd LaMaskin (he/him): And here are the results can coordinate ages that come in pretty solid at 408.
Todd LaMaskin (he/him): All grains give CIT tim's ages between 408 and 410 with a weighted mean age of 408 Point five.
Todd LaMaskin (he/him): So we believe that this confirms our maximum deposition of ages of around four or five to 409 that we interpreted from laser ablation ICP Ms.
Todd LaMaskin (he/him): And it also suggests that grains that are less than 408 ma represent some component of lead loss or even date metamorphic events.
Todd LaMaskin (he/him): Now we also have one additional rim analysis rim analysis which we were very excited about the laser ablation spots suggested that the age was 340 ma with very low thorium uranium.
Todd LaMaskin (he/him): This single tip when analyzed via CA ID tim's comes back with an age of 41 and thorium uranium point 004.
Todd LaMaskin (he/him): So this suggests metamorphic ISM CIRCA for to ma and later led loss that was picked up by the laser ablation It also suggests a very short duration of only about 6 million years.
Todd LaMaskin (he/him): Between the youngest igneous corps at about 408 and the oldest metamorphic rims and grains and so i'm going to skip the summary.
Todd LaMaskin (he/him): And i'm going to say that our data are not consistent with the eastern rollie terrain, is part of carolinian.
Todd LaMaskin (he/him): Not only the igneous crystallization ages of carolinian but pollock and others report Detroit or con ages from classic sequences of carolinian know younger than 530 ma and with just minor amounts of precambrian grains.
Todd LaMaskin (he/him): Our data are, however, really consistent with the eastern rally terrain being genetically related to the maidens nice portion of the Gucci turay.
Todd LaMaskin (he/him): Sorry, so, in addition, our data are also consistent with the eastern rollie terrain being genetically related to rocks of the northern appalachians and we've been suggesting this since about.
Todd LaMaskin (he/him): here's a plot of our rocks and age getting older and you can see, by a quick comparison rocks of the eastern rollie terrain compare best with rocks of Ghana Nigeria.
Todd LaMaskin (he/him): So we suggest that rocks of the eastern rollie terrain bear a strong lightness to those of gandy area, as well as Perry laurentian arcs in the northern.
Todd LaMaskin (he/him): appalachians and it's not just to try to work on ages it's rock types defamation history and metamorphic.
Todd LaMaskin (he/him): ages as well and i'll just show very, very quickly we've got some plots here of ages from Ghana, Nigeria and the northern appalachians as well as the iPad and realm.
Todd LaMaskin (he/him): Those are shown in pink and rocks from the eastern raleigh terrain are shown in blue and even just a rapid visual assessment shows.
Todd LaMaskin (he/him): Real strong likeness of these with each other to our interpretation is that these Eastern rally to rain rocks as well as the maidens nice represent displaced fragments.
Todd LaMaskin (he/him): From the northern appalachians and I encourage you to stick around for Dr blake's talk next, which will help us explain that a little bit better Thank you.
Dave Blake: Thank you Todd I was a great talk your colleague would be very proud of you, but it's a good data.
Todd LaMaskin (he/him): up is.
Dave Blake: Are there any quick questions out there before we move on.
Dave Blake: Any questions at all.
Dave Blake: we're a little bit over time, so to keeping on track.
Dave Blake: The next speaker will attempt to load his PowerPoint.
Todd LaMaskin (he/him): So our next speaker is Dr Dave blake.
Dave Blake: Let me see here.
Todd LaMaskin (he/him): Dr blake's talk title is southern appalachian hinterland freeway system before the it five and I 95 corridor wars Eastern Piedmont fault system and lyft photonic tectonic tech terrains in North Carolina.
Todd LaMaskin (he/him): And we can see it.
Dave Blake: And I will start the timer.
Dave Blake: Thank you Todd so before I begin.
Dave Blake: I would like to acknowledge several groups I like to acknowledge the north Carolina geological survey for providing state map funding since.
Todd LaMaskin (he/him): 1992 to.
Dave Blake: conduct a lot of Eastern Piedmont mapping in North Carolina the usgs for multiple at matt projects.
Dave Blake: The.
Dave Blake: Numerous graduate undergraduate students from unc w that have helped in the field, and then the geologic materials lab and then day bar bow and juvenile sex than.
Dave Blake: At the tectonics and sedimentation lab down the University of South Carolina that facilitated a work for Patrick and jack nolan and brandon peach on their zircons your chronology.
Dave Blake: And here's our unc w department of earth sciences at art and ocean sciences ED map research group Robbie morrow on the right to brand impeached Aaron rise to Patrick finnerty and last and youngest jack nolan and I appreciate their efforts and their PCs.
Dave Blake: So you've all now seen this map, you now have an understanding that we're looking at the list of tectonic realm and domain subdivisions along the appalachian origin.
Dave Blake: Looking at the northern appalachian origin versus the southern appalachian origin and i'm going to focus on the southern appalachian in red box, which is the north Carolina Eastern Piedmont, and also made a compilation map.
Dave Blake: For the north Carolina and a portion of the Virginia Eastern Piedmont, and so we're focusing on carolinian and as Todd as mentioned and Patrick you know relationships potentially with the good excellent domain so.
Dave Blake: Back in 2012 I suggested in the talk that the transition from.
Dave Blake: A North 40 to 50 East strike on the eastern Piedmont fault system in South Carolina to a North 15 east.
Dave Blake: strike in.
Dave Blake: North Carolina and Virginia might represent a restraining then in a trance professional fault zone.
Dave Blake: And these strands are highlighted the eastern Piedmont fault strands are highlighted originally documented by hatchet and all 1977 and Andy Bob your chick did a lot of work on this.
Dave Blake: These fault zones as well, and they include you know the major strands are the light Gordon hi Alice up in Virginia.
Dave Blake: The House there and guests and damn and Virginia down in the South Carolina as well as the macon and then the not Bush creek fault zone, which is further east to the West so we're evaluating the relationship of carolinian to other domains, and as Todd mentioned.
Dave Blake: Jim hibbert back in 2007 and remembered another suggested that East of the not most creek.
Dave Blake: These would be considered other carolinian terrains so in the process and conducting state map mapping and especially.
Dave Blake: East of the light Gordon share zone, we started to investigate that and I was able to get a series of ED map students to conduct geologic mapping and intercounty a chronology so the students were primarily evaluating look the logic relationships and fit like the green shirt stacy's.
Dave Blake: roxanne Eastern rally terrain and Western spring up terrains and cross and west of the make and falls on.
Dave Blake: Patrick tectonic insert common characteristics of Eastern rally terrain mythologies.
Dave Blake: Were there correlations with carolinian suggested by GM and 2007 or good excellent suggested by Stuart Stuart for our in 1985 and Bob Patras 2010 or gandy area suggested by Aaron rice and, more importantly, brand and peach in 2018.
Dave Blake: And then we evaluated fabric elements and orientations along and west of the making fault zone was it a textural refolded doctoral and or extension default development.
Dave Blake: was making a discreet high strains own, or is there a wide zone of transformational ductile strain that crust of duck the flow and contraction over printing much of the eastern rally terrain.
Dave Blake: And so.
Dave Blake: I began this by compiling two different geologic and let the tectonic maps of Eastern Piedmont and North Carolina and Virginia.
Dave Blake: The one on the left is modified both of them are modified from recent nc state map mapping.
Dave Blake: The State geologic map of North Carolina and mark carter's map as well as a template by Patrick affinity and 2020.
Dave Blake: In North Carolina the little logic map on the left, the data was provided by phil Bradley at the end cgs and shows are compile geology up to this point in the raleigh and Henderson one to 100,000 sheets.
Dave Blake: The map on the right is my Luther tectonic element interpretation of all the lip allergies.
Dave Blake: And the bounding Eastern Piedmont fault system strands, including the nut Bush creek late Gordon highlights hollister.
Dave Blake: Late Gordon in North Carolina megan Gaston damn down in new very southern portion is the terrible creek and then the falls lake and middle creek faults as well.
Dave Blake: And so they bound, a series of super structural trains that i've tried to highlight and shades of green and then infrastructural trains try to highlight in blue.
Dave Blake: And so the superstructure terrains our greatest bases and as Todd indicated the NSA Patrick has noted, you can see the ages.
Dave Blake: beside them neoproterozoic for spring hope and roanoke rapids easternmost Carolina and and the Carolina terrain and then, once we get into.
Dave Blake: Northern up in Virginia that dinwiddie which we talked about by Mark Carter they're beginning to get early devonian ages triplet it's not clear.
Dave Blake: we're getting these early devonian ages in the eastern rollie Western rollie has neoproterozoic and so that's why one of the separations between the eastern and western, although the Western hasn't been studied in detail, yet.
Dave Blake: But it does exist across the lake Gordon shares them and then the crab tree falls lake and then our goose island domain up in Virginia.
Dave Blake: And these are treated by multiple Pennsylvania permian granted toys related to the allegheny and rodney and then, finally, we see the Cross cutting and some parallel normal faults.
Dave Blake: Related to mizzou I break up pangea and a lot of them are following these dexterous strands of the eastern Piedmont fault system.
Dave Blake: highlighted in yellow is in an eight quad compilation map that was put together by Aaron rice, as part of his work with the North Carolina geological survey.
Dave Blake: And you see that here and it highlights to the West between enough Bush creek and like Gordon work by skip starter for the North Carolina geological survey and then on the east side in the spring hope terrain that's a mapping by skip and and Paul sacks.
Dave Blake: In between, as the eastern rally terrain and you can see, highlighted the the five different ED map projects that tried to evaluate the mythological relationships with a dynamic relationships and the granted toy.
Dave Blake: pleat ons and you also know the yellow diamonds, these are the zircons sample locations that Patrick and Todd just described to you.
Dave Blake: And so we can see the the major bounding faults of Eastern rally terrain, the light Gordon faults and under sears and in the House, their fault zone.
Dave Blake: And then the making false zone, so the making and like Gordon really bound the eastern rally terrain and represent the.
Dave Blake: ranch component of the hypothesis for transgression in this region, and then there are two major fault structures, they is making sin form and then the after Nana form that appear to represent other contractual component to potential late paleozoic transgression of the region.
Dave Blake: Here are two.
Dave Blake: planar linear fabric element maps and.
Dave Blake: presented by and put together by air and rice compiling all our work from state map and ED math and you can see the.
Dave Blake: general strike orientations on the left for the composite cheerfully Asians, and then he highlighted various dip angles in the colors noted underneath that map, so you can really see in black the the major sub vertical share zones for the light Gordon and the making and the.
Dave Blake: hollister and then you can see that chunk of change in between that has a variety of it bangles are related to structures that are developed in the eastern raleigh terrain, which you know.
Dave Blake: looks like a big cross will block or gigantic for for class and then the map on the right shows all the delineation trends, as were, as well as various angles, a plunge.
Dave Blake: And again, you can highlight the major shears owns the light Gordon making and hollister based on the trajectories of the strikes and the linear fashion trends.
Dave Blake: So it's a it's an interesting compilation of data, and it has helped us to create this regional transportation or fabric element.
Dave Blake: and actual shares own block diagram so Arthur this might address your question as far as to the West is the Carolina terrain and then.
Dave Blake: fabric elements and then not Bush creek and a leg gardener primarily so vertical as this big decks for shares and with the Western rally terrain in between mostly granted toys and some amphibious lights.
Dave Blake: and also in West side North East side South extra kinematic indicators, then inside the eastern rally terrain, we find a variety of natural kinematic indicators that are folded but they consistently show ISA north and west side.
Dave Blake: eat left side or the side south.
Dave Blake: senses this year and then there's those large macro scale fold structures that fold them, but they still consistently show this deck general kinematic indicators.
Dave Blake: And then on the east side is the making falls down, and it is not as steep as the to shear zones to the West and that'll have implications potentially in a minute, but it seems to over print the East side of the eastern rally terrain in the West side of the spring hope terrain.
Dave Blake: And so here's a obligatory obligatory mom oh come back here.
Dave Blake: computer's acting funny come back.
Dave Blake: Stop.
Dave Blake: Goodness gracious.
Dave Blake: There we go looking for I feel picture john you the regional compositional layering the composite cheerfully ation and over prints the entire mostly the entire eastern raleigh terrain in the upper right hand corner is a field picture from brandon peaches field area show on the F1.
Dave Blake: ice climbing folds over printed by upright F two folds and he created a map blab block diagram to show the interference pattern.
Dave Blake: created by these structures and they are very analogous to the mapping patterns that we see.
Dave Blake: In the lower left is a series of beautiful outcrops in robbie's field area, this is a view to the east of schools have muscovite fish that are swimming West side North East side South and show the.
Dave Blake: shallow or dip of the macon fault zone and then in patrick's field area, you can see a kinematic indicated extra kinematic indicator.
Dave Blake: marked by muscovite as well as fiber look silly tonight, so the metamorphic ISM was occurring during the extra flow and then last but not least in the lower right hand corner is a.
Dave Blake: sample from robbie's field area beautiful sample of a relatively underperformed class inside of ultra mile and I in the macon shear zone.
Dave Blake: serving as a delta type wing poor for Class beautiful sample that Robbie still has so clearly we're seeing these these textural kinematic indicators so.
Dave Blake: For a while now i've been proposing that these terrains represent the portions of a strike slip duplex and contraction or extension, although doing given them restraining Ben, I feel that the contractual serves us better and in the process of.
Dave Blake: Evaluating that we could be looking at these infrastructural trains popping up through the superstructure trains as a positive flower structure.
Dave Blake: In addition, Woodcock and Fisher suggested that these duplex structures and trains could be cut out of both of the wall rocks they could be cut out of one of the wall rocks as a cognitive leading duplex.
Dave Blake: They could be cut out of one of the wall rocks and juxtaposed against adjacent wall rocks as a cabinet trailing duplex or the trains can be completely exotic or a locked in this as a trailing or leading duplex.
Dave Blake: So that leads credence to the reasons or con do chronology on the left in the process of jack conducting field airy in acton.
Dave Blake: We evaluated his park town, Nice and and that rock clearly is a nice but it doesn't show a lot of kinematic indicators and it's in February face he's in a few garnets in the shift.
Dave Blake: But it's not highly deformed like the middle branch and the Liberian is described by Patrick that has composite sheer fabrics good mineral stretch linney ation.
Dave Blake: And you go across the contact in the park town just doesn't look as the form so based on this work and some of my prior work jack's proposed that this is a.
Dave Blake: mill branch and Liberia might be a pedal in a half flower structure and rooted in the light Gordon Shearer zone it depth and.
Dave Blake: and higher metamorphic grade and then thrust outward into the East over top of lower grade still actively face he's park down Nice, and this is not a new idea of Stewart proposed it back in 85.
Dave Blake: Paul sacks proposed at 1999 skip stoddard proposed it in 2009 and 2011 and.
Dave Blake: So it's the wrench component potentially of the transgression with the subsequent contraction leading to the Bowling event and exposing the park town as a.
Dave Blake: window or exposing the park down through a window of the mill branch just in Liberia nice thrust plate, and then, subsequently, a lot of this stuff.
Dave Blake: gets over printed by the allegheny and pleat ons and one of the results of jack's study was that the wise Pluto which has always been marked as a separate playtime really appears to be a face ease of the roles will baths and has connectivity.
Dave Blake: And so, Patrick and jack have already summarized all the zero con work and, as our.
Dave Blake: Todd and, as you noted from Todd there seems to be a strong correlation a comparison of lifted tectonics or con ages and Gary or abalone but the fibula faces metamorphosis would be more associated with cam darien rocks and.
Dave Blake: Bob hatcher back in 2005 and 10 suggested that the laurentian gone one and collision may have been a bleak transgressive rotational and north, south zipper.
Dave Blake: So I started looking at cheers own junctions and zip ring and freeways, but for separating you need both semicircle and textural shear zones and the map on the right is a.
Dave Blake: forum surface of all our eastern Piedmont fault system maps strands and they're all extra nobody reports any sinister ol.
Dave Blake: So, if you look on the left hand side you'll see the ellipse that i've noted of textural junctions and freeways, and you know our cheer zones appear to be a freeway system.
Dave Blake: And those junctions facilitate decks real flow and defamation patterns, with some of the trains, being the form and some of them, perhaps acting as rigid bodies, this is from cache and platt in 2017.
Dave Blake: And in the diagram just below the rigid sector you'll see that extra chairs down next to the freeway and actual spheres zones highlighted again with the shortening direction so i've.
Dave Blake: mark that on the map to the right potential shortening directions for the sheer zones The other thing is these junctions tend to fall into four types T times and mill types.
Dave Blake: But ours tend to be why types and Lambda types and passion and platt suggest that they are the most common and they can accommodate significant displacements, in theory, so that leads credence to the idea that.
Dave Blake: Perhaps the eastern payment trains that are infrastructural, including the dinwiddie and the Eastern rally terrain and perhaps a triplet might be far traveled.
Dave Blake: On the right is a map that Robbie compiled for his thesis from Jim hubert's 2006 map showing all the thrust faults.
Dave Blake: The normal faults and then the decibel strike slip folds so we can see up and down the origin, there appears to be a you know series of these decks will share zones.
Dave Blake: and other people have noted that maybe this is a large transform system carrying some of the structures from the northern appalachians to the southern appalachians and perhaps our rocks are.
Dave Blake: Related to go SLIM and perhaps our rocks and good excellent are related to Ghana Nigeria.
Dave Blake: And that was also proposed by brandon peach and his thesis back in 2018 and he suggested Eastern Piedmont trains might be.
Dave Blake: game theory and apollonian domain type rocks so we're trying to put together this regional hypothesis, the zircons clearly as Patrick noted you can't judge Iraq by it's cover in these direct conduit chronologies really facilitating things.
Dave Blake: So sort of Canada in summary preliminary zircons moto site uranium lead here chronology and muscovite thermo chronology.
Dave Blake: suggest some following things the diagram on the right, Peter hacker off is our new faculty Member at unc w and conducts geothermal crow chronological studies and provided this data set so magnetite crystallization of metamorphic Sir Con and deliberate Liberia nice 382 315 by Patrick.
Dave Blake: Granite magnetism to 90 822 86 by Schneider and sampson and.
Dave Blake: jack conducted.
Dave Blake: zircons your chronology on the garden Chi night shifts and peers to record a 287 metamorphic a.
Dave Blake: bill haynes back in 2001 conducted work on muscovite in the duck though Jones bar normal fall and obtain.
Dave Blake: ma ages and then Peter half or offs recent age on the gun kind of anxious from the crab three terrain might suggest that horse uplift and are gone closure current by about 251 ma so trying to get some.
Dave Blake: Some analytical data to all our years of mapping results, and so I leave you with some parting thoughts, this is.
Dave Blake: On the left diagrams that I put together back in 2001 showing some of these ages and then this half flower structure and so perhaps we're still looking at transportation that might be.
Dave Blake: Transit transitioning into trans tension and then actually cross the extension with the breakup of pangea.
Dave Blake: So I know it's a long way over time and.
Dave Blake: i'll leave questions to the end, thank you.
Dave Blake: whoo.
Dave Blake: that's it i'm way over time.
Todd LaMaskin (he/him): we're going to move on to our next talk Thank you Dave do stick around folks at 410 we have a break coming up, but I want to go ahead and move us quickly into our next talk.
Todd LaMaskin (he/him): By mark Carter of the usgs and others and the title of his talk is G chronology of paleozoic rocks of the dinwiddie terrain central, eastern Virginia Piedmont, USA and mark whenever you are ready, you can share your screen.
mark carter: All right, thank you Todd can you hear me OK, I.
Todd LaMaskin (he/him): can hear you well.
mark carter: Alright, that may change I don't know i'm sharing my screen now.
mark carter: share.
mark carter: Can y'all see this.
Todd LaMaskin (he/him): We can.
mark carter: Oh great alright.
mark carter: hey Dave thanks for taking half my time, but that's okay.
mark carter: Sorry it's all right, I forgive you.
mark carter: Before I begin I do want to give a big big shout out to the organizing committee GSA concepts, this has been a very just an awesome meeting and.
mark carter: I want to just want to congratulate you all for for putting together a very, very fine meeting for this, so today i'm going to kind of build off of what.
mark carter: The previous presenters have given here my co authors and I presenting today New York our logic results.
mark carter: From a belt of rocks off to the North East of what we've just seen in the eastern P monitor Virginia that we refer to as the dinwiddie terrain.
mark carter: rocks or this terrain or border to the north and Northwest by the good excellent terrain and the mesozoic Richmond and ashlyn basins, to the southwest by the roanoke rapids terrain.
mark carter: And overlaying by coastal plain cover off to the east.
mark carter: This belt rock was formerly map as a single weight paleozoic battling for example is on the 1993 state geologic map of Virginia, but we now know it to consist of several rock types.
mark carter: of varying ages, these include early paleozoic mica schist a middle paleozoic Meta granted toyed and late paley's granted.
mark carter: zircons from these rocks preserve evidence for at least two paleozoic metamorphic and defamation events.
mark carter: So in this presentation will also compare the dinwiddie terrain to adjacent Eastern Piedmont terrains and speculate a little bit on its domain all affinity within the paragon one in terminal.
mark carter: And the paragon one in realm and then also want to just point out quickly draw your attention to the disclaimer at the bottom as that you don't record or screenshot any of this presentation is these data or preliminary.
mark carter: So, before presenting our new data here's some background context, the new and the updated detailed geologic mapping in Central Eastern Virginia began in 2005 by the Virginia division of geology human resources.
mark carter: Through the usgs and see GMP state map program and continues through both that program and the nc GMP fed map Program.
mark carter: That initial round of mapping in the mid 2000s delineated several rock types of side at that time to the lake paleozoic Petersburg granted.
mark carter: And these included massive Granite for for reddit Granite fully at Granite and layer Granite Nice, as well as in civilized and fell six years country rock preserve and xena lists enclaves and wall rock screens.
mark carter: In 2012 Robert beach ball and brynn owens reported a new tim's uranium lead zero con ages for two of these rock types massive granted it falls the James river in downtown Richmond.
mark carter: At 296 million years and for for critic Granite adjacent to the Richmond basin little bit off to the West at 299 million years, these were the first new ages on the Petersburg granted since lead William shrimp age 315 million years back in 1993.
mark carter: baseball nolan's also data to Grenada xena lifted about 400 million years, and this was the very first indication of older rocks within the battle if that we actually had a date on other than the xena list and civilizing listen the failsafe shifts.
mark carter: So only on the following a Granite and layer great at night for recognizes major rock types in this bill.
mark carter: We question whether or not the 400 million year old age obtained by boost mobile and owens applied to more of these folio that rocks from our geologic mapping so in 2018 we begin a sampling program for both new uranium lead your chronology.
mark carter: and supporting geochemistry throughout this belt This included collecting samples massive Granite from the southern portion of the outcrop.
mark carter: For granted toward and one sample of fell six years for the trials are con analysis coupled this with nearly 50 geochemical samples that we collected or compile from existing data.
mark carter: For the massive Granite one sample came from the jack quarry near subtle and then the other one came from the.
mark carter: near the town of wit open the southern portion of that outcrop l both samples are massive coarse grained decal grinder look around it, that locally preserves the course affiliation that may be primary magnetic wearing or tectonic.
mark carter: The first sample of fully at rock was actually collected from beach quadrangle from abroad belt of map fully admit granted toyed marcy Okay, and I.
mark carter: marcio key with the Virginia vision of geology mineral resources not collected the rock we sampled it.
mark carter: Using the laser ablation technique at the usgs lab and Denver results from that sample inclined us to date additional samples for confirmation using the Stanford usgs shrimp lab in California.
mark carter: All of these samples were moderately to strongly fully eight Meta Granite towards the nicest with varying degrees and metamorphic over print.
mark carter: We also collected one sample of fail six shifts from the map scale on clean for the trials our content analysis and the sample is a mica schist from the barn air quadrangle.
mark carter: But it's the same rock is it a big map wall map scale wall screen down along the Southwestern margin of the train.
mark carter: Multiple a deformed and civilized and alternate alternate for rock also occurs in the list within the.
mark carter: and massive for for the grants.
mark carter: So let's start with the results from the massive Granite and the southern part of terrain both of the width sample at 321 million years.
mark carter: And the jack corey sample at 350 million years are about 15 to 20 million years older than similar rock stayed at Richmond area about boosie Walden owens.
mark carter: So this means to us anyways that that the Petersburg bath length as we've had to redefine it likely consists of two distinct pleat on separate of spatially into and poorly.
mark carter: also note that the ages in the inherited course from the jack corey sampler from 554 million years to 376 million years.
mark carter: you'll probably start recognizing similarities in age dates with what we have with what Todd has reported with what Patrick report it and what Dave reported just second go to.
mark carter: The neoproterozoic Cameron ages do suggest a paragon on an affinity for this terrain, based on those inherited course.
mark carter: To the foley eight it rocks now affiliated middle green Eric rocks were originally included in the Petersburg granted his older faces, it was.
mark carter: rubbish wall and Brian owens who opened the door to suggest that these rocks were actually not part of the late paleozoic igneous system.
mark carter: And so to confirm their results we initially sample the rock from a broader belt of map fully managed granted not from us a list or enclave.
mark carter: And that yielded a laser ablation coordinate 416 million years to confirm that age we collected for additional samples for what we're now calling the poker shot nice for shrimp analyses.
mark carter: Three of those samples yield a good crystallization ages, ranging from 423 million years from the sample North Richmond to 402 million years my sample willfully eight it rock at the falls into James in downtown Richmond.
mark carter: Also note desert call and read data from the falls of the James sample 299 years the room ages and nearly identical to the agent team for the nearby massive granted.
mark carter: By boosie Walden owens rim data from the other samples are also consistent with les paley's or Petersburg Granite intrusion.
mark carter: The falls in the James sample also yielded to nearly two early middle paleozoic ages for inner metamorphic rooms with low 30 am uranium ratios recall that are jack quarry sample you live in an inherited core age from about this time to.
mark carter: or D child or Detroit or con analysis also yielded some surprising results in the Richmond area geologic mapping suggest that mica schist occurs xena list within the fully admit granted toy, but our our crops up there aren't or the best.
mark carter: Put that caveat here we interpret the peak age population at 527 me.
mark carter: To be the maximum depth age of the sample because that age.
mark carter: fits with slightly more of the inherited for ages from the shrimp analyses how about we just simply can't rule out the possibility that the maximum depth additional age for this sample is somewhat younger.
mark carter: which would require the mica schist to be devoting cover to the slightly older older poker shock Nice that are granted toys, rather than country rock within it.
mark carter: Regardless the Detroit zircons hears do suggest a paragon one and source for these rocks rather than a richie and source which should preserve far more means and protozoa zircons.
mark carter: let's go back to our zircons from the poker shot Nice, which gives us a glimpse into the metamorphic history of this terrain.
mark carter: Work on in the Nice crystallized from about 422 400 million years ago and some Sir Kong grew around do produce or too early paleozoic in here to course.
mark carter: sometime between crystallization in about 375 million years ago or con did experience the period resort option in Brazil fracturing.
mark carter: In about 375 million years ago the brutal fractures with field with newser Kong growth and with by type minerals, these are called also grew his rooms for about 325 to 300 million years ago contemporaneous with hot temperature intrusion and the Petersburg granted into these rocks.
mark carter: So now, if we combine the second picture genesis with field and better graphic observations we can construct a temperature time pass through the poker shock Nice and Petersburg granted.
mark carter: moving from left to right prior to intrusion of the poker shock Rana towards field evidence from poly deformed and civilizing list.
mark carter: suggest country rock experienced and civilized faces metamorphosis and defamation, probably in the early paleozoic.
mark carter: If we assume a cambria maximum deposition will range from the file system that all country rock mythologies are approximately the same age.
mark carter: poker shot granted towards and true to train beginning about 420 million years ago but we're quickly uplifted.
mark carter: When polka shock nice developed it's fully ation remains an unanswered question was it just after intrusion, or about 375 million years ago during the period of zero con room growth.
mark carter: we're currently de Mon as i'd open overgrowth from country rock and from the photoshop nice to try to resolve this issue.
mark carter: What we do know is that that by the time the Petersburg branded and true to the terrain starting about 325 million years ago.
mark carter: That fully ation had already developed, because we do see high temperature contact metamorphic mineral growth on foley ation planes.
mark carter: It is also about this time that we see evidence for evergreen just lower and familiar faces metaphor morph isn't.
mark carter: concurrent with allegheny and double faulting along the hollis and not away river fault zones that border the terrain week tectonic fully ation observed in the late paley's or granites may have also formed at this time to.
mark carter: Now that we've defined the DEMO terrain let's compare it's igneous metamorphic and definite defamation or history with Jason terrains.
mark carter: A conventional view is that Petersburg granted are shown on the 1993 state geologic mapper virginian treated rocks of the roanoke rapids terrain, both to the southwest and to the east.
mark carter: Beneath coast playing cover in this still may be partly true for the late paley's or brands, but are there similarities between the older rocks of the two terrains.
mark carter: First, we now know that a major label is defaults on what we call the not away river fault separate rocks at the dinwiddie terrain from those of the roanoke rapids long their shared Southwestern border.
mark carter: In this false oh melancholic fabric dip steeply to the West was shallow South pleasing mineral stretch delineation suggesting top to the north of northeast kinematics.
mark carter: Practice our recent work and the southernmost part of the terrain this contact was interpreted on the 1993 state map is a system of mesozoic brittle faults that may have over printed in earlier ductile ductile fault rocks or ductile fabrics.
mark carter: Secondly, published ages from the roanoke rapids terrain is Todd pointed out, are mostly older than about 600 million years.
mark carter: We only have one inheritance or calling from the dinwiddie terrain at 631 million years and there are no modern geographic.
mark carter: Do chronological results that indicates lori and devonian magnetism in the roanoke rapids.
mark carter: What we don't know at this time is when and civilized two branches bases metamorphosis occurred in the roanoke rapids or how it relates to early middle paleozoic events that we've recorded in the dinwiddie.
mark carter: You didn't know that two terrific terrains had to share the common late paley's or metamorphic and defamation history along their fault zone boundary.
mark carter: Another view holds that the Petersburg granted stitches the hollis fault zone and the correlations months older rocks may exist with the consultant terrain, to the Northwest.
mark carter: And certainly there are many tempura correlations between these two terrains.
mark carter: For example, the age of the savage and fill it at 552 million years old does fall within the range of inherited trials are cons from the dinwiddie.
mark carter: But we also know that category of chemistry of the savage differ significantly from volcanic arcs composition of dinwiddie terrain and civilized his brain owens and his students pointed out just a couple of years ago.
mark carter: More importantly, devonian igneous ages for parts of the veins nicer only slightly younger than the poker shock Nice and known as it ages for brand new like faces metamorphic ISM and the goose island bracket the age for lower temperature metamorphose into dinwiddie terrain.
mark carter: But there are some major differences, the abundance of Paleo protozoa to neoproterozoic to early paleozoic to trial igneous and metamorphic zircons from the goose island compared to only three zircons we similar ages from the den woody.
mark carter: What we can say for sure is that, although the two terrain for Jason bother close to lay paleozoic allegheny and rodney there is some evidence for a shared history as early as the middle paleozoic.
mark carter: Some reason there we go.
mark carter: And these are called data also provide some additional insight into the broader picture paleozoic construction of the appalachian origin.
mark carter: First, both inherited cirque on ages and trials are con analyses point to a paragon one and affinity for dinwiddie terrain country rock.
mark carter: Whether or not these rocks are more closely aligned with carolinian domain in the southern appalachians one of the paragon one and terrains in the northern appalachians either gone derrida or apollonian that remains ambiguous, but then, when he terrain rocks are.
mark carter: Almost most likely not have the range and realm secondary ages for the bulk of shock nice really slightly older than those recently reported ages for magnetism in the raleigh terrain is Patrick pointed out to the southwest.
mark carter: and slurry devonian magnetism in both the dinwiddie and raleigh terrains corresponds in age to the classic acadian rajini in the northern appalachians However, the younger paleozoic zircons from dinwiddie rocks correspond well with organic advance in the southern appalachians.
mark carter: So just summarize dinwiddie terrain doesn't consist of a single late paleozoic facelifts that is composed of three major units of different age neoproterozoic.
mark carter: To paley's country rock selenium devonian Meta Granite toys are polka shock Nice in Pennsylvania permian granites of the redefined Petersburg Granite.
mark carter: Although these data are limited to us to use our phones poker shot nice neighbors or of evidence for metamorphosis.
mark carter: At 375 million years ago and zero con rims clearly do record the link paleozoic Petersburg Granite intrusion about 300 million years ago.
mark carter: Within the Petersburg ran at the southern, to wit Sutherland on is 15 to 20 million years older than the northern Richmond Quinton inherited and trials work on data point to a paragon one and source for the dinwiddie terrain, like other Eastern Piedmont trains and southern appalachians.
mark carter: There are a few little logic in need and fewer to portal correlations between the dinwiddie terrain and immediately.
mark carter: adjacent terrains but their so called data or similar to those report it from the raleigh terrain, further to the southwest but it's certainly difficult to structurally correlate the two terrains as they don't share a common fault boundary.
mark carter: And I want to thank you all for listening.
Todd LaMaskin (he/him): All right, thank you very much, mark.
Dave Blake: Thank you, mark you got three minutes.
mark carter: How do I really.
mark carter: All right, yes, I can take a question.
Dave Blake: Any questions.
mark carter: Conventional view that's great.
Dave Blake: One thing I thought about mark.
Dave Blake: In thinking about this freeway system that you know to be a zipper you gotta have sinister on deck for emotion and i'm wondering if.
Dave Blake: there's a way to say earlier on, that rally train and dinwiddie might have been related and that might be some evidence for one of these little sin Mistral motions before it gets all over printed by the backfill.
mark carter: So yeah that that well could be, and you know, as you will know you and Peter and I and jack and Patrick we were all going to be going out.
mark carter: Last summer, I think, to actually look at the not away river falls on we've got we've got some good data.
mark carter: That suggests textural but.
mark carter: we've we've just mapped it basically we really need to get out there and take a look at it and, of course, that field trip that i'm talking about was cancelled because of coven.
mark carter: So we do need to get out there, we do need to grab some samples we some oriented samples and really take a look at that let's make sure that that fortran is decks route could have a component of centers for defamation on it as well.
Dave Blake: Right.
Todd LaMaskin (he/him): All right, thank you Arthur I see you have a question but i'm going to ask if we hold it until maybe right before the break and go ahead and get started with Robbie.
Todd LaMaskin (he/him): So our next speaker is Robert morrow and his talk is titled recognition and structural significance of macroscopic courts veins in the Carolina terrain central South Carolina so Robbie whenever you're ready.
Robert Morrow: You see if I can find this thing.
Robert Morrow: Everybody hear me.
Yes, we can.
Robert Morrow: Do i'm gonna hide you people.
Robert Morrow: Can you see my slideshow.
Todd LaMaskin (he/him): Yes, we can.
Robert Morrow: Alright, so today i'm going to talk to you guys about some fundamental concepts of geologic mapping and that's the identification and tracing of with a logic contacts on God maps.
Robert Morrow: The accurate replacement of with logic contacts is inherently difficult in places that have will lack adequate rock exposure and that's especially true in the South Carolina people.
Robert Morrow: Nowadays traverse mapping is aided by lidar data sets and low resolution airborne geophysical surveys.
Robert Morrow: What the lidar base maps allow you to do is predict where outcrops might occur, based on their G morphic expression and that becomes incredibly important when you have low topographic relief or if the area that you're mapping in is is well developed.
Robert Morrow: So today i'm going to talk to you about some results of new mapping in the Carolina terrain in South Carolina.
Robert Morrow: The mapping was done with traditional traverse mapping techniques, with the aid of white our hill shades.
Robert Morrow: to locate prominent G morphic features.
Robert Morrow: When I feel checked some of those prominent few GM morphic features a lot of times they were boulder trains of courts and courts veins that extended four kilometers on in in some cases across an entire quadrangle, and so the bulk of this talk is going to be talking about.
Robert Morrow: What those courts feigns look like what they might represent and what their relationships are with the surrounding rock types So here we go.
Robert Morrow: So at a bare minimum courts veins form from the precipitation of hydrothermal courts rich fluids along openings and surrounding rocks.
Robert Morrow: Their common features found in southern appalachian Piedmont and they're widely described in field notes, but makeable courts veins are rarely shown on published one to 24,000 scale geologic maps.
Robert Morrow: So, as I said before, this study is going to describe relationships between orange courts veins and the Jason country Rock in the Carolina terrain of central South Carolina.
Robert Morrow: So we seen this map a few times before.
Robert Morrow: we're in the carolinian domain looking at green shirts face sees and amphibians, faces rocks.
Robert Morrow: In part of carolinian, which is an assemblage of paragon one and I own art terrains.
Robert Morrow: In South Carolina Carolina terrain crops out mostly across the central part of the state and it's an alternating it consists of alternating belts of amphibian faces and green shoots faces rocks the Carolina terrain in this map here is shown in blue I don't know if you can see my cursor.
Robert Morrow: In blue is bound to the West by the Charlotte.
Robert Morrow: terrain, the boundary between the Carolina and Charlotte terrains is the chappelle show Arizona and it's not on this map but it's a, shall we se dipping sheer zone.
Robert Morrow: It is the Carolina train is bound on the east, side by the savannah river train, which is another employee faces belt of rocks and they are separated by the steeply Northwest dipping textural mohawk share zone, which is one of the actual strands of the eastern people and fault system.
Robert Morrow: The Carolina terrain is cross cotton and trusted by both devonian and pennsylvanian permian futons.
Robert Morrow: devonian meaning are being the cloud street Granite an egg nice sweet and pennsylvanian permian granted, such as the liberty hill Granite Granite and and others.
Robert Morrow: So we're here in Columbia today but i'm going to take you about 34 miles West to the lake Murray field area, which is in this box over here and we'll look a little bit closer what the rock types look like and what the relationships are.
Robert Morrow: So we're zooming in on the lake Murray area.
Robert Morrow: The map pattern here is.
Robert Morrow: can be broadly defined as a series of southeast verging and declines and sin cline's.
Robert Morrow: The structural you oldest unit is the personal information which is a group of day Siddiq and ryota crystal toughs and related volcanic sedimentary rocks that were deposited in the neoproterozoic approximately 550 ma.
Robert Morrow: They are overlain by the rich texts and emory formations, which are both groups of solace a classic brock's the rich text is mapped on the West side of the persimmon fork.
Robert Morrow: It contains mostly laminated soapstone very rare wacky and metal assault.
Robert Morrow: And the emory formation is mapped to the east of the personal information and is mostly courts rich self stones much stones and courts erudite.
Robert Morrow: These rocks contain similar to try those are con age distributions but they're separated based on.
Robert Morrow: For the most part it's the grain size so rich text is mostly fine grain it's interpreted to have been deposited in deeper water environment, whereas the memory formation contains more coarse grained faces and is interpreted to been deposited in a near shelf shallow water environment.
Robert Morrow: So, following the deposition of the rich text and memory formations these rocks were shortened in an event called the del mar defamation.
Robert Morrow: The structures that we see that are considered del mar are ruthless is a clientele folds that are.
Robert Morrow: That are inter folio folds they're very rare don't see them very often.
Robert Morrow: And that that's their primary manifestation.
Robert Morrow: So, following that defamation event the asbury park information was deposited as a successor basin over top of the emory formation here, it has a relative age date of 503 ma based on trilobite fauna discovered by don C chord and some students back in the 80s.
Robert Morrow: And it is separated from memory formation by an angular unconformity turn the Harris branch on conformity.
Robert Morrow: So, following the deposition of that unit these rocks were short and again in an event called the as bill upon defamation, it is very well constrained to between 503 and 415 ma if you can sense my sarcasm there.
Robert Morrow: The the 415 ma is based on the crystallization ages of Sir cons in the clouds creek igneous sweet here which intrudes into the asheville upon formation.
Robert Morrow: Following that.
Robert Morrow: That defamation event.
Robert Morrow: army so uh what I meant to say is the fold structures that you see here are primarily a manifestation of the asheville upon defamation event.
Robert Morrow: And it follows following those folds this whole the whole Carolina terrain was caught up in the eastern Piedmont volt system where we have ductile brittle faulting.
Robert Morrow: folding and textural strikes what faulting.
Robert Morrow: It is so we can see here the the mohawk fault zone here to South.
Robert Morrow: Which is the southern boundary here, and these rocks were translated up to the Northeast on at fault system.
Robert Morrow: So on to our new mapping so over the past five years, three new quadrangles were mapped in the lake Mary area that includes delmore sue the South and Johnston.
Robert Morrow: The area is heavily vegetated and the lakeshore is rapidly being developed, especially in the case of del mar up here, and so we employed, the use of lidar data sets to look and see where we might be able to find outcrop easily and map some of these relationships.
Robert Morrow: So when we look at the lidar a little bit more closely.
Robert Morrow: The few things stick out to me, first and foremost, you can see, the fall line kind of well defined here, where you have the Atlanta coastal plain settlements on laughing on to the Piedmont rocks.
Robert Morrow: And secondly, you can see several northeast trending prominent topographic linens and when a lot of those were field checked, many of them were kilometer wide courts veins or courts ridges.
Robert Morrow: So, as I said, many of the linear features were courts ridges they were mostly massive courts.
Robert Morrow: But many of them exhibited.
Robert Morrow: Highly fractured shattered looking textures.
Robert Morrow: Some had cat a classic textures others had evidence of ductile shear strain.
Robert Morrow: Some had you know they had developed courts rotting linear ization and others had a buggy courts filling fractures and evidence of crack seal fabric, development and others were rough shaded.
Robert Morrow: The predominant orientation of these courts ridges was between North 55 and 65 East, which is some parallel to the regional affiliation development in the Carolina turning rocks so over the next series of slides i'm going to go over.
Robert Morrow: What the rocks looked like on either side of these courts ridges.
Robert Morrow: So, interestingly enough.
Robert Morrow: The frequency of these courts ridges picked up within the gravitational boundaries between many of these between the persimmon fork and its overlying Meta sedimentary.
Robert Morrow: The overlying sedimentary rock types fermented sedimentary rock types so along the person fork and rich text contact.
Robert Morrow: up in del mar we saw two kilometer long.
Robert Morrow: Courts rich on the North side was rich text soapstone and on the South side there's beautiful.
Robert Morrow: fill in attic fells IQ medical clinic rocks.
Robert Morrow: See, as you move down to the southwest into the sorta South quadrangle there was a series of disk continuously continuous courts ridges that range from one to about five kilometers long and from about five to about 3030 meters wide.
Robert Morrow: And again on both sides of these courts ridges we had.
Robert Morrow: My own attic varieties of the metal volcanic rocks and the Meta sedimentary rock so here, you see beautiful delta's type asymmetric with a class that showed texturally symmetry.
Robert Morrow: up here near like Murray, we had fractured zones and with term of a linear fracture patterns.
Robert Morrow: In some of the metal volcanic rocks and again down here in salita here's a shared conglomerate on the contact between.
Robert Morrow: on either side of the of the courts ridges with asymmetric with a class that showed extra asymmetry.
Robert Morrow: These rocks developed.
Robert Morrow: The sheer blow the cheerful creations, where he had sc fabric development as services were primarily North 55 East the sea surfaces strike about 65 East and the sea prime surfaces when when they showed up we're about North at East and all of these were predominantly Northwest dipping.
Robert Morrow: If we go to the other side and look at the person for emery contact again we see similar relationships along one major courts vein here in del mar if cat classic textures and some of the courts folders blocks of phil knight containing these blocks of shared courts.
Robert Morrow: and
Robert Morrow: As you approach the contact from the emory side.
Robert Morrow: If you might recall the emory information is interrelated Meta sedimentary rock so they developed beautiful multi layer fold patterns.
Robert Morrow: In this case, we saw dexterous folds with faults cutting up through the hinges of some of the extra folds the the faults strike predominantly North 40 east.
Robert Morrow: And in D, here we have a faulted solidified silt stone here in the Johnston quadrangle along the person fork emery boundary with some tops up to the southeast of displacement showing the emory being reversed followed up to the south, against the contact.
Robert Morrow: If you go.
Robert Morrow: To the emory as well upon contact which was only mapped in the del mar quadrangle if you approach it from the North East.
Robert Morrow: or pardon me from the Northwest again beautiful multilayer folds the layering was dexterous faulted in these beautiful duplex structures, he saw.
Robert Morrow: The fold intensity really become more apparent where he had.
Robert Morrow: The Axial surfaces of these older as bill penfolds became more vertical the fold hinges or the enrollment angles became tightened and we saw textural.
Robert Morrow: Extra strain on on those that actually attenuated some of the whims of the earlier.
Robert Morrow: As bill pond folds are the older older D two folds.
Robert Morrow: We also saw blocks of phil knight.
Robert Morrow: In this one field outcrop you could walk from emory formation good folded medicine stone into kind of a button the phil knight into as build upon.
Robert Morrow: And so you know.
Robert Morrow: Basically, the pattern, we were seeing was really intensely folded in faulted emery formation.
Robert Morrow: Courts ridges phil knight and then as built upon and we saw that same similar relationship across the three different contacts.
Robert Morrow: So about this point, I was in covert quarantine for about four months stuck in my code field office and i'm starting to think about you know what these relationships mean clearly there's some textural motion along these contacts.
Robert Morrow: And so, went on a deep literature dive trying to figure out what was going on here and I found this one Paper describing these features called coral reefs.
Robert Morrow: which they described as these large linear courts ridges that are commonly associated with strikes law office strikes at fault systems, this example is from South China and in this scenario, as you approach this court's re for this court's core.
Robert Morrow: You had cat a classic and my lunatic textures developing in the wall rocks cat a classic textures in the courts.
Robert Morrow: veins are the courts urges the core of the fault or the courts reef was massive courts and again, as you moved into the other wall rock you had cat a classic and my own textures and so.
Robert Morrow: From you know this literature review, I was saying that you know some of these features are consistent with what I was seeing with Caroline with the Carolina terrain rocks.
Robert Morrow: So.
Robert Morrow: What is the regional significance of this well when I parted the courts veins over top of some of our room low resolution geophysical data, a lot of these matched up.
Robert Morrow: With some geophysical lemons and in black here we can see some geophysical infer faults from new indoor but all 1998 where they looked at the arrow magnetic data Daniels or pardon me.
Robert Morrow: They looked at some of the older aromatic data that Daniels eventually re re compile.
Robert Morrow: And they drew these just GEO physically in for faults and so a lot of these courts veins correspond to those faults well if we zoom out and look at.
Robert Morrow: South Carolina is a whole these fault strands are interpreted to be part of the Eastern Piedmont fault system so here, you see a series of strikes with duplexes inferred from these gene physical limits.
Robert Morrow: So I.
Robert Morrow: In the grand scheme of things of what do these courts veins me well in an idealized textural simple sheer system, you get a predicted.
Robert Morrow: You get predicted orientations of faults and subsidiary faults.
Robert Morrow: So the the main sheer direction is denoted why and you get P shears and our shares that are 15 to 32 piece years or 15 to 30 degrees counterclockwise to the y shears and the our shares or 15 to 30 degrees clockwise to the Weiss years so.
Robert Morrow: clendenin a new in-orbit 1997 and Clinton and Mauro in prep for the mohawks here zone east of this field area just ease of this field area define a wide direction or why principles here direction of North 65 east.
Robert Morrow: appear a piece here direction or orientation of North 40 East and ours of our shares of North 80s.
Robert Morrow: And, most of these courts veins and their orientations our sub parallel to either the Y or the peers peashooter direction.
Robert Morrow: And so my interpretation is that, basically, the courts ridges and the faulty Caroline contact carolyn train contacts represent.
Robert Morrow: These different strands of the eastern Piedmont fault system that are that have been previously and matt and these strands utilize that and I saw trapeze at the context propagate.
Robert Morrow: So, in summary in central South Carolina large courts veins are map of both the 120 4000 scale.
Robert Morrow: The courts veins contain a variety of textures suggesting repeated cycles of hydrothermal courts precipitation.
Robert Morrow: The courts veins in the rocks that's around them contain ductile and critical fabric elements and kinematic indicators.
Robert Morrow: That kinematic indicators indicate predominantly textural slip and the preliminary interpretation is that these are sways of the eastern people and fault system that propagated along the formation contacts.
Robert Morrow: So with that i'll ask if I have time i'll ask you guys some questions have you all ever seen this before or something like it and did you make a different interpretation.
Robert Morrow: Or do you have any questions for me and Thank you everyone and appreciate your time.
Dave Blake: Thank you, Robin anybody have any questions.
Dave Blake: we're supposed to go into a break, so the next talk will be at 425 so anybody's got a question for Robbie you're more than welcome to to ask him, one thing I would say is, you know that looks a lot like may feel mountain.
Dave Blake: You know the coral reef.
mark carter: hey Robbie.
mark carter: yeah i'm did they did you have something else say.
Dave Blake: No Sir all right.
mark carter: hey Robbie.
mark carter: or any of those courts veins or court rages mineralized have you seen any of that.
Robert Morrow: So i'm the one quartz quartz vein that I showed that was in del mar on if you trace it along strike you'll find I ended up in this big tilled field, and there are.
Robert Morrow: Why midnight pseudo morphs of pyrite that are in some cases, you know a little bit smaller you know they fit right in your hand almost the size of a fist.
Robert Morrow: You don't see the the pristine pyrite there because it's all been weathered and kind of the upper soil environment.
Robert Morrow: But that's something that we care, you know we see quite often.
Robert Morrow: A lot of times you see pyrite or alignment i'd pseudo morphs after pyrite in the energy information and the rich text formation along the precision for contact so i'd say yes.
mark carter: Okay, good good keep an eye ball out for it and going forward, you know that it sounds like they're a little different from error classic solidified cataclysm sites back East here are further east but.
mark carter: We recognize those up in up in southern Virginia is some of being quite mineralized so it's a it's an interesting situation there.
Dave Blake: here's one of the live and I cubes that Robbie gave me made it it's a dice.
Dave Blake: and see how big they are.
Robert Morrow: it's a loaded die.
Dave Blake: Any other questions for Robbie.
Dave Blake: I will, with that will.
Dave Blake: Take a five minute break and resume again at 425.
Todd LaMaskin (he/him): So if anybody has any other questions for any of the previous presenters.
Todd LaMaskin (he/him): And they don't want to take a break for five minutes.
Todd LaMaskin (he/him): feel free to unmute and ask away.
Anji Shah: Robbie.
Anji Shah: usgs how you doing.
Robert Morrow: Good how are you doing.
Anji Shah: Does any of your study area overlap, where we have the new era mag data.
Robert Morrow: Yes, the the Far Eastern part of the del mar quadrangle.
Robert Morrow: And what and the quadrangles to the south of that and so i'm on that 12 quadrangle map I think Gilbert and stedman are included in there and so that's where we're going to be doing some of our sampling for the initial earth MRI sampling.
Anji Shah: Well i'd say let's I mean I i'm thinking, the new mag data is much higher resolution and let's chat about how that can be helpful to what you're doing.
Absolutely.
Robert Morrow: Of course, unfortunately folks Well, unfortunately, fortunately I gotta go get a coven shot so.
Todd LaMaskin (he/him): that's four.
Todd LaMaskin (he/him): that's fortunate.
Robert Morrow: Thank you.
Willis Hames: Robin that was great.
Todd LaMaskin (he/him): Thank you.
Willis Hames: yeah shut up man.
Frank Ettensohn: All right, let's see if I can.
Frank Ettensohn: Share screen here.
Todd LaMaskin (he/him): So our next speaker is frank edmondson and the title of his talk is using the confluence of flexible models bios photography and absolute dating to determine the duration of classic wedge formation into appalachian acto phases, and we can see your screen just fine.
Frank Ettensohn: Very good Thank you so much.
Frank Ettensohn: i'm it.
Frank Ettensohn: looks like i'm the lead off on the on a on a small sedimentary interlude here and I like to use sedimentary evidence and working.
Frank Ettensohn: toward the history of the appalachian area and particular classic wedges and so i'm going to try to combine flexible models here and dating based on bios trigger fi radio metric dating and things like that to talk about the dirt timing and duration of two classic wedges.
Frank Ettensohn: Where we have good bio strata graphic data, so let me see if I can move this.
Frank Ettensohn: So.
Frank Ettensohn: When I started this my first question was well what isn't a rajini and I.
Frank Ettensohn: determine I wasn't quite sure what it really was what I thought it was the definitions, I saw.
Frank Ettensohn: But an older definition basically suggested and includes the defamation, with the rocks and generation of a mountain mountain is typography and that's important and generating classic wedges However, when we look at a more modern definition here.
Frank Ettensohn: Talk about again structural processes brittle and more plastic processes, but this one shows a disconnect between mountainous typography and formative processes.
Frank Ettensohn: And that kind of bothered me, because we need some sort of typography in order to get classic wages, so the questions arose, you know how to quit classic wages form.
Frank Ettensohn: Are the parts of it are rajini what is the duration of an erogenous, how do we tell and what does terms like sin or genetic wedge post or a gigantic wedge really mean in terms of origin.
Frank Ettensohn: So where do you go to find these answers to these questions, I think, from a sedimentary standpoint one really needs to look into the foreign basin.
Frank Ettensohn: which of course is generated by the rajini through defamation loading and to do this, we need to basically a model that helps us understand how loading generates the sedimentary responses.
Frank Ettensohn: And we need to have some reasonable way to approximate the timing or today these sedimentary responses so i'm first going to look at those items and then show my my two examples where we do have good bios taker feet.
Frank Ettensohn: So, how does fallen base and loading work well, some of you probably have seen these these slides before, but this is based on work by Quinlan in beaumont and beaumont and several of his co workers basically and basically we can divide kind of.
Frank Ettensohn: tectonic event into a period of active loading and a period of relaxation, based on the beaumont models during active loading we have typically it starts out in the subsurface with thrusting and folding things like this that never reached the surface, or maybe some likewise.
Frank Ettensohn: We have little classic influx so in the absence of classic in flux, we get black organic rich muds all the organic matter coming up here.
Frank Ettensohn: From the upper part of the sea and typically substances so fast that we develop a water stratification, which is what the picnic line is.
Frank Ettensohn: And we get the preservation of black organic rich mutts very little sedimentary in flux at this particular time and, of course, as subsurface loading.
Frank Ettensohn: continues on basically the Basin and the bulge move on as well, and as that ball moves that generates a basal unconformity so all of these sequences are unconformity bound.
Frank Ettensohn: Now, and time to this is relaxation the relaxation period actually combines two different types of relaxation and i'll go to the next slide to talk about that.
Frank Ettensohn: So here again is that time to relaxation, and according to the bomani models basically we have two types of relaxation that go on one is loading type, the other is unloading type.
Frank Ettensohn: The first is loading type relaxation, and after the loading has occurred and become static it puts a stress on the lift sphere, the lift the sphere responds.
Frank Ettensohn: And the the load starts to subside but in the substance, basically, the bulge and the base and move back.
Frank Ettensohn: And during this time we get a very deep bass and we have enough superficial load up here to start to generate drainage nets and this starts to fill.
Frank Ettensohn: Typically, with deepwater plastics things flourished like what I call flourish like plastics this continues on until basically the load is largely gone.
Frank Ettensohn: And there's kind of an equilibrium between the sea and the hinterland area and during that time, we may have a very brief interval of carbonates or shallow water classics but after that load is gone.
Frank Ettensohn: The lift this fear response again by rebound and as it rebounds it uplifts parts of the former for olin basin and we get finer classics these are marginal marine plastics they're often periodically exposed, so we get red beds things like that a great variety of.
Frank Ettensohn: Different faces and when I call molasses like molasses like sedimentation and then another technical phase will occur, we get another unconformity.
Frank Ettensohn: So the resulting sequence might look something like this.
Frank Ettensohn: This is a sea level curve right in here, this shows the typical mythologies over here on the left.
Frank Ettensohn: and actually the names in here are actually or division units and some more division dates and i'll talk more about those.
Frank Ettensohn: But this is an example from the taconic for Lynn basin up in New York.
Frank Ettensohn: And we start out with a unconformity at the base some transgressive carbonates maybe some bent nights representing volcanism here is our black shale, which represent maximum substance.
Frank Ettensohn: This is followed by flourish like typically turbid aight deepwater del take types of things, and then we go into the equilibrium phase by this time the load is largely gone.
Frank Ettensohn: And there is kind of an equilibrium between the hinterland, and the for London, we may get widespread carbonates or shale very shallow water carbonates and shells.
Frank Ettensohn: And then, this is rebound or unloading type relaxation we get marginal marine plastics with red beds, a vast variety of various different faces.
Frank Ettensohn: And these I call kind of my last leg, so this is the typical sequence, and we see this repeated many times in the appalachian basin and another foreign basis.
Frank Ettensohn: And just as an example down here at the bottom I picked the north Alpine for olin basin it's a classic.
Frank Ettensohn: And here is a sedimentary sequence in that base, and that is a techno phase cycle and that's what we call these things are technical phase cycles.
Frank Ettensohn: And we start out with our baseline conformity transgressive carbonates dark organic rich muds flourish like the blue here is kind of an equilibrium unit with shells and and.
Frank Ettensohn: literal sands and then we go into louisville read beds molasses like and another unconformity where the next tech phase will begin, and so this is what I typically call a tech phase cycle, and it is based on the.
Frank Ettensohn: flux role models of beaumont and his co workers.
Frank Ettensohn: If we look at a larger scheme, for example, the economy and around rajini and we look down here, this is a parallel to strike cross section, represented here by this red line A, B, C D is up in here.
Frank Ettensohn: And this is the iconic phase, which is represented by the blue martinsburg fallen base in here, what we see is we see two of these techno phase cycles.
Frank Ettensohn: So this is a lower tech face cycle that we call the blench in tech to face some people call that a separate rajini and again, you see the unconformity transgressive carbonates black shells flourish like molasses like this is the peconic technical phase which most people think of.
Frank Ettensohn: When they think of to Connie and we have a basal unconformity transgressive carbonates black shales flourish like and then molasses like.
Frank Ettensohn: and, interestingly, you can see that the progeny is di acronis it migrates northward in Time starts out down here in the south.
Frank Ettensohn: And it turns out that these tech phases appear, at least in the appalachian setting to be mediated by continental promontory.
Frank Ettensohn: So it's the Virginia promontory that is causing this tech phase convergence up here with the New York promontory that is causing this tech to phase.
Frank Ettensohn: And there's actually a third phase Shin by this Green basin that's slurry and it's related to convergence up here.
Frank Ettensohn: Further, further to the north, but we're going to worry about these things so Roger nice typically occur in a series of pulses that we call tech two phases and every technophiles has a typical sedimentary response in the for land base and.
Frank Ettensohn: Now this is looking at the appalachian for olin basin and again based on the actual models of Bowman and his.
Frank Ettensohn: Co workers coworkers This seems to work well and the sedimentary regime and the appalachian for land basin.
Frank Ettensohn: Starting here in the middle or division and going all the way up into Pennsylvania permian we have 1310 faves cycles during five different erogenous we include the salinity in here, which is there's evidence that's present up in the northern appalachians.
Frank Ettensohn: Now, have all of these technical face cycles bio stratego fee is really only good good enough to work on this in two of these, and this is the peconic tech phase shown right here.
Frank Ettensohn: And it is largely a New York tech phase, and then the new acadian up in this particular area, right here.
Frank Ettensohn: This pastor tigger fee is based on corner dancing graph delights this bio stock ticker fee is based on ammonites.
Frank Ettensohn: And so, this is the flexible model, and this is the sedimentary sequence that we expect to see the sequence may be truncated by an overlapping techno phase.
Frank Ettensohn: or an or rajini partner rajan he may not go to completion, before the next one begins so next we're going to look at the timing aspect of this.
Frank Ettensohn: We need some way to reasonably date these sedimentary sequences and, as you can gather basically what we use is bio stratigraphy to do that.
Frank Ettensohn: And until the early 2000s we really didn't have the means to do that, but a lot of work by James OG Felix grant steen and their co workers.
Frank Ettensohn: They have developed means of extrapolating and interpolating from radio metric dating of that nights astral on nominal cycles.
Frank Ettensohn: magnetic polarity stable isotopes photography and sea level trends, to come up with a linear.
Frank Ettensohn: dating scheme that you see here on the left side side of this diagram, and this is again an ordovician timescale from one from Cooper and Sadler and it's a large compilation of timescales, but.
Frank Ettensohn: What they've enabled us to do now is to take ios or tigger fi and relate bio strict tigger feet to absolute times obviously it's approximate.
Frank Ettensohn: But it's better than we've ever had before so where we have good bios photography we may be able to date, some of these events from the fall and basin far more precisely than we have in the past.
Frank Ettensohn: So we're going to look now here at this upper to connick tech phase that we've talked about again this is parallel with strike.
Frank Ettensohn: And so, if we look at the various units, and here we have our baseline can for me unconformity the utica shale is a black shale course the names change when you go to different States.
Frank Ettensohn: But this is the utica shale, and the utica shale based on these flexible models represents a period of active loading, this is the time when there was a lot of defamation going on, when subduction is probably most active.
Frank Ettensohn: And then the rest of this period, and this is what i'm calling a technical phase in as part of an Iraq, you need the rest of this is actually relaxation.
Frank Ettensohn: And we have our unloading type classic wedge a flourish like classics here here is the little equilibrium interval in here the plasticky and here is the marginal marine red bed sequence the Queen stun.
Frank Ettensohn: So called kingston delta, which represents the last like face and, interestingly, at least for me.
Frank Ettensohn: How little time is actually involved in active loading, so this is that the entire technical phase.
Frank Ettensohn: Last about 7.5 million years the act of loading phase is about 1.1 million years relaxation, where we get our to plastic wedges is about six point for me and years so defamation.
Frank Ettensohn: act of defamation, if you believe this kind of scheme of things is really a very small part of any kind of a texture phase or agenda of event.
Frank Ettensohn: We go to the neo acadian the other place where we have good bios retainer fee and the neo acadian of course starts up here was first defined up here in Massachusetts.
Frank Ettensohn: Probably represents collision of gone bwana with Puma and avalon and.
Frank Ettensohn: get a pincer movement these come on down force Carolina to move on, down to the South in a dexterous transformational movement.
Frank Ettensohn: But when we look here at the sedimentary sequence the riddle is burger the sunbury shale active loading about 3 million years the price pocono borden granger, this is the fish like these are all basically turbo nights and deep water delta things i'm.
Frank Ettensohn: Talking about a little more time the Pennington Mon chunk, this is the marginal marine read beds, so the total relaxation here is about 34 million years the act of loading period is only 3 million years.
Frank Ettensohn: And this is rather unusual it's a very lengthy techno phase, most of them on the order of 1015 million years, this is a very large one and that may be related to the fact that the entirety of the Carolina terrain had to basically transfer massively.
Frank Ettensohn: Sub duck and this thing is about 600 least based on on measurements today is about 650 kilometers, but this is a very large tech to face.
Frank Ettensohn: So anyway, the conclusions are number one how you define a mirage any is is really important.
Frank Ettensohn: or rajneesh can be divided into shorter pulses a text aneurysm on the order of a million to maybe few 10s of millions of years.
Frank Ettensohn: tech phases include initial period of intense loading and defamation during rich relief between a subsiding basin and rewriting arising load is generated.
Frank Ettensohn: And this is followed by a period of relaxation when our classic wedges form, there are two types of classic wedges that accommodate the relaxation period.
Frank Ettensohn: And we're biased photography is precise and well known, it may well be possible to determine the duration of a Raj knees and there are parts.
Frank Ettensohn: and basically that's what we've done with the economy and tectonic tech phase that's economy or rajini and the entire neo acadian or rajan Thank you so much.
Todd LaMaskin (he/him): Thank you, frank, we have time for one question if anybody has anybody anyone real quick.
Todd LaMaskin (he/him): Okay, well, thank you, frank.
Todd LaMaskin (he/him): My my watch click to 445 as I was speaking and so i'm gonna go ahead and announce our next speaker.
Todd LaMaskin (he/him): Dave mocha is here to talk to us about the critical role of recycling in the evolution of Detroit desert con age systematics and along lived basin and importance of a multi proxy approach to provenance analysis showing us some evidence from eastern lorenza and we can see your screen.
Dave Moecher Univ. Kentucky: All right, great Thank you very much, can you hear me Todd.
Todd LaMaskin (he/him): Yes, we can do.
Dave Moecher Univ. Kentucky: All right, yeah so.
Dave Moecher Univ. Kentucky: we've heard a lot about to try to work on and i'm not trying to be a scold or anything I want I mean, I want to encourage everybody to use all different types of the title zero con proxies but we've known for a long time that there are issues with Detroit zircon.
Dave Moecher Univ. Kentucky: What i'm talking about here today has been published in recently in GSA bulletin, and in geology so you can go to those for some of the details.
Dave Moecher Univ. Kentucky: So the pros and cons of details are con there are many and most of you are familiar with those who have practice this the.
Dave Moecher Univ. Kentucky: Uranium lead zero con faithfully records the magnetic history of the source terrain.
Dave Moecher Univ. Kentucky: and its refractory meaning it's unlikely to undergo resetting in normal sedimentary systems and it's durable it's virtually indestructible and it's likely to be retained, with the trial courts in the classic settlement system.
Dave Moecher Univ. Kentucky: it's also become very easy to analyze anybody can do it, including me and my high school students who are working with us it's easy to prepare.
Dave Moecher Univ. Kentucky: image and then it's easy to generate high large in sample suites and data sets that are collected very rapidly almost mind boggling the fast now.
Dave Moecher Univ. Kentucky: bill Thomas used to say, the good news about the titles or con is it's refractory and durable and the bad news about the titles or con is it's refractory and durable it's okay it's certain to be recycled and not record the complexity of the sedimentary tectonic history.
Dave Moecher Univ. Kentucky: The ease of analysis generally means people can't it's not practical to look at all your grains and examine them in terms of their textures and it also generates an overwhelming amount of ages for me, sometimes that are.
Dave Moecher Univ. Kentucky: Maybe some of you are more capable of handling big data sets, but I just find it overwhelming how much data, there is now.
Dave Moecher Univ. Kentucky: The age of zero con is the ultimate age of the magnetic source of the zero con it's not the age, the immediate source of the sediment and that's the purpose of provenance studies.
Dave Moecher Univ. Kentucky: Zero con has also been shown to be one or rajini behind and we've talked about that today earlier about how in the appalachian system and Eastern laryngeal there's virtually no sin or genetics or con there's a little bit, but not much.
Dave Moecher Univ. Kentucky: And then there are other issues as well differentials or con fertility of source terrains.
Dave Moecher Univ. Kentucky: sighs sorting and variable uranium concentrations that lead a metabolic disease have all been shown to produce age biases, but we still press on in spite of all of those things.
Dave Moecher Univ. Kentucky: And, and in spite of an admonishment from Campbell at all, this is a pretty old publication, this is from 2005 and it was recognized early on that.
Dave Moecher Univ. Kentucky: This this was the title zircons study of the Navajo sandstone and the Himalayan drainage systems and they showed that their results cast doubt on the reliability of the uranium lead method when using the absence of other techniques so.
Dave Moecher Univ. Kentucky: However, that hasn't stopped us from pressing on, but I think the important point is it's important to consider other inputs to your provenance analysis.
Dave Moecher Univ. Kentucky: And so, as an example of that we looked at the title Manas I and two triangles are con in Pennsylvania permian settlements in the appalachian basic.
Dave Moecher Univ. Kentucky: And this on the left, you see a comparison of the two titles or con age spectrum for these samples and the Detroit will monetize age spectrum.
Dave Moecher Univ. Kentucky: And although they tend to record the same major organic events, you can see that the relative amplitude of the two different systems is flipped.
Dave Moecher Univ. Kentucky: OK zero con is dominated by the grenville age modes with very little of the paleozoic age mode and it's just the opposite in the Manas I.
Dave Moecher Univ. Kentucky: Age spectrum, so what would you interpret this to mean are we is there cons are telling us that the granville is the ultimate source of most of the settlement, the mana sites are telling us that paleozoic rocks are the dominant source of most of the settlement well there is.
Dave Moecher Univ. Kentucky: We went back or I went back and looked at all of those models i'd grains and started to classify them, based on their textures and on the right, you see.
Dave Moecher Univ. Kentucky: What I would what I referred to as metamorphic mana sites over here okay that tend to be inclusion free they can have complex story and zoning patterns, but the main thing is, they tend to be inclusion free.
Dave Moecher Univ. Kentucky: Then you've got another set of mana sites over here that are just chock full of inclusions they have lower thorium content.
Dave Moecher Univ. Kentucky: They have nice rounded to tribal textures as well, and then you get things in between where you've got a core.
Dave Moecher Univ. Kentucky: And older core that's overgrown by a younger generation of mana sites so there's clearly something more to the story here than just the Manas ice ages that are given in the age spectrum on the left.
Dave Moecher Univ. Kentucky: So I went back and looked at fin sections of.
Dave Moecher Univ. Kentucky: The sedimentary rocks and you can find digest you find mana sites that look like this on the Left Okay, these are these are so this is from the fin section.
Dave Moecher Univ. Kentucky: you've got these inclusion rich mana sites crystallizing in the matrix here's the thorium map to show that they're relatively low authority, but the important point is is they're just chock full of inclusions.
Dave Moecher Univ. Kentucky: We did electron micro probe age dating of these mana sites and they tend to give a range of ages.
Dave Moecher Univ. Kentucky: Okay, they have fabrics that are indicate, they have not been deformed So these are interpreted as crystallization ages of what we refer to as diet genetic or low grade monitor.
Dave Moecher Univ. Kentucky: Okay, so they grew in the classic proto list, and in this particular case, these are examples of neoproterozoic go coin, that a classic rocks that have a late.
Dave Moecher Univ. Kentucky: protozoa deposition age, so they would have been buried during the cambrian in order to vision and at that time is when you would have had the guy genetic Manas it and low grade Manas died for me so with this is the interpretation, if we go back to the monastery data, you see that these.
Dave Moecher Univ. Kentucky: textures that are inclusion free give one age relationship, they tend to be the grant the garden the granville zircons and some of the paleozoic zircons.
Dave Moecher Univ. Kentucky: But then all of the died genetic mana sites tend to be much younger okay all basically paleozoic in age, not all of them, so what we're seeing here, then, is the.
Dave Moecher Univ. Kentucky: That these the tried all that these we've got what we call the title diet genetic Manas they formed in an older settlement.
Dave Moecher Univ. Kentucky: And that was eroded and we and, therefore, by definition, recycled and it proves recycling so that's what's really important about the diet genetic.
Dave Moecher Univ. Kentucky: directed the detritus diet genetic modified now these Manas it are probably came out of.
Dave Moecher Univ. Kentucky: Meta sedimentary rock as well Meta settlements are more fertile for mana site generation than your typical I tied granted as tight grants are very fertile for Manas I but.
Dave Moecher Univ. Kentucky: If there's a lot more the Meta sediment, at least in the appalachians Then there is the type granites so if we've got these mana sites that form died genetically.
Dave Moecher Univ. Kentucky: And are recycled, how then do we interpret the the titles or con well, we need to look use another system and that's where we decided to.
Dave Moecher Univ. Kentucky: Do a much more detailed study of the title nine has died in the titles or con in the appalachian basin, so we looked at two units in the.
Dave Moecher Univ. Kentucky: Central apple agent based in an Eastern Kentucky, this is the grundy and the core of information there laterally equivalence lower Pennsylvania and age.
Dave Moecher Univ. Kentucky: The grundy is a classically of immaturely thick era night and the carbon is a mature coursera night so lift a logically they're very different.
Dave Moecher Univ. Kentucky: Okay texturally they're very different the corbin court screens are really well rounded the grundy is not so these have always been interpreted as.
Dave Moecher Univ. Kentucky: Probably the grundy being the more proximal and the carbon mean being more distal in terms of its transport history into the central appalachian basis.
Dave Moecher Univ. Kentucky: And so we're going to interpret these results in the context of a model for the Pennsylvania pan continental river system of archery and grab okay so we're down here in the central appalachian basin Okay, the grundy.
Dave Moecher Univ. Kentucky: grundy little face she's is is probably being derived from transfers drainage is and the corbin from longitudinal bait drainage is, but you can see.
Dave Moecher Univ. Kentucky: The size of the drainage basin, that is inferred for the Pennsylvania in eastern laryngeal so we're going to come back to this.
Dave Moecher Univ. Kentucky: This large scale drainage system when we talk about the carbon.
Dave Moecher Univ. Kentucky: The details around age spectra for these samples are shown here so you're looking at a composite of all of our carbon samples that composite of all of our grundy samples.
Dave Moecher Univ. Kentucky: And you can see the dominance here of the granville age moans again the auto industry when again.
Dave Moecher Univ. Kentucky: granville age doublet you can see some smaller granville age modes in there as well, Eastern grand Eastern Granite right.
Dave Moecher Univ. Kentucky: Now, in temporary focus on the grundy first of all, you can see that the an early cambrian composite from eastern lorenza is.
Dave Moecher Univ. Kentucky: overlaps the grundy really well and, in fact, if you calculate the lightness using the message method of sad kosky at all there at 9% similar which is practically identical Okay, in terms of this lightness parameter.
Dave Moecher Univ. Kentucky: Also, the grundy you can't see the late neoproterozoic old code two titles or con composite because it's buried by those other.
Dave Moecher Univ. Kentucky: Age peaks that are basically overlap on it, so the grundy and although we also have a likeness of 80%, which means that the grundy and cambrian our life so here we've got a.
Dave Moecher Univ. Kentucky: likeness values tell us that we've got a really precise location for the provenance of the settlement for the grundy it's coming out of the blue Ridge it's coming out of the basal cambrian and the neoproterozoic oculi classic units, so we can be much more specific in terms of.
Dave Moecher Univ. Kentucky: Identifying the provenance but it's also consistent with recycling of the cambrian classics as well in the camp, excuse me recycling of the neoproterozoic in the cambrian.
Dave Moecher Univ. Kentucky: The in comparison to grundy and corbin likenesses only 69% so really these lightness value is only mean much to me if i've got something to compare them with So you can see that the corbin is dominated by older age molds.
Dave Moecher Univ. Kentucky: And so, in terms of carbon provenance we're going to come back to that later, but we can really link the grundy to southern appalachian.
Dave Moecher Univ. Kentucky: basement and Meta sedimentary sequence that are exposed in the blue Ridge.
Dave Moecher Univ. Kentucky: If we look at the dirt the title mana sites in the grundy and carbon, we see the exact same thing that we see elsewhere in that previous study we see these grains that we interpret as metamorphic and then we've got these detritus die genetic mana sites as well.
Dave Moecher Univ. Kentucky: here's the age data for the grundy and corbin the title metamorphic mana sites and for the.
Dave Moecher Univ. Kentucky: Title died genetic mana sites, now there aren't as many of these grains as there are two titles or con and that's one of the drawbacks, but you can still see the very.
Dave Moecher Univ. Kentucky: unique and definitive age modes that the grundy and corbin are both dominated by paleozoic mainly iconic and acadian.
Dave Moecher Univ. Kentucky: metamorphic Manas I and the the title that and the diet genetic mana sites are also the same age, although they tend to be a little bit younger as well and that's what you would expect, we would expect to see.
Dave Moecher Univ. Kentucky: ages that are actually younger than the deposition age of the Caribbean corbin and the grundy because there's died genetic mama side forming in them.
Dave Moecher Univ. Kentucky: Alright, so we've got this distinct contrast between the monastery Missouri con again.
Dave Moecher Univ. Kentucky: What we did was use double dating to trails dirt on double dating using the uranium lead system and the uranium thorium helium system.
Dave Moecher Univ. Kentucky: To try to learn more about the origin of the and the, you know these are the processes that these grenville zircons have gone through.
Dave Moecher Univ. Kentucky: So what this diagram shows is the uranium thorium helium age versus the uranium let age and these lines are all lines of constant age difference.
Dave Moecher Univ. Kentucky: Most zircons in an origin are going to be zoomed early on in the history.
Dave Moecher Univ. Kentucky: And if they have delta T values that are greater than about two or 300 million years, then that indicates an increased probability that they've been recycled.
Dave Moecher Univ. Kentucky: notice that the most of the zircons for this study, have all been reset to paleozoic ages and other words they've seen temperatures in excess of the closure temperature for helium diffusion in the uranium lead system.
Dave Moecher Univ. Kentucky: So they've been reset they've seen higher temperatures something more has happened to those the title zircons.
Dave Moecher Univ. Kentucky: So, if we look at the details are on data, then of course we've got these dominant Lee uranium lead ages for the.
Dave Moecher Univ. Kentucky: Dominant granville uranium lead ages and then uranium thorn healing majors are mainly Paleo sword.
Dave Moecher Univ. Kentucky: And that's the same as the betrayal Manas i'd grains So how do we reconcile these differences between desert con these three systems that are telling us.
Dave Moecher Univ. Kentucky: something different, about the provenance of these settlements.
Dave Moecher Univ. Kentucky: Now this is kind of complicated so i'll try to walk you through this.
Dave Moecher Univ. Kentucky: Okay, think about what's going to happen to granville the trials or con as after it crystallizes in the granville during the auto and and she went again and then it's going to be exudes during by various rates.
Dave Moecher Univ. Kentucky: At various rates through the neoproterozoic and these the steepness of these lines, you can imagine a whole range of possible paths getting to the surface.
Dave Moecher Univ. Kentucky: So the surface is here on our temperature depth diagram this, these are cons correspond to the great granville sedimentation episode of rain bird hey if there was a.
Dave Moecher Univ. Kentucky: A one of the world's largest origins ever must have generated another origin or continents scale classic system and so those would have that would have been the first.
Dave Moecher Univ. Kentucky: cycle settlement for settlement cycle that those outcomes would have gone through at in that pan continental river system, but that pan continental reference system in classic wedge was eroded Okay, and in the neoproterozoic, then the.
Dave Moecher Univ. Kentucky: Those classic rocks were deposited little bit before after 600 million years ago, so this is the age of the post granville sedimentation.
Dave Moecher Univ. Kentucky: We had formation of the great unconformity and then the cambrian rocks would have been a second period of recycling for these settlements, then those.
Dave Moecher Univ. Kentucky: basal cambrian and neoproterozoic sediments were metamorphose during the two car garage any they would have gone to higher temperatures and greater depths and that's the point at which their.
Dave Moecher Univ. Kentucky: Their their various other systems would have been formed, so we had to try to die genetic modified forming.
Dave Moecher Univ. Kentucky: We had Detroit Oman and metamorphic Manas aight forming in these rocks.
Dave Moecher Univ. Kentucky: And we had muscovite forming in these rocks, and this is based on the work of the auburn group he's done detritus are gone are gone dating a muscovite in the appalachian classic system, but they tend to be paleozoic as well.
Dave Moecher Univ. Kentucky: So all of those rocks for metamorphosed and with their cargo of granville zircons those granville zircons then would have been reset.
Dave Moecher Univ. Kentucky: And as those rocks were zoomed going into the late paleozoic you, they would have had their systems reset and they came back to the system, then and back to the surface and we're zoomed in the late pennsylvanian and then went into the.
Dave Moecher Univ. Kentucky: The foreign basin so we've got two different main cycles of recycling there could have been.
Dave Moecher Univ. Kentucky: One day in one be there could have also been the other rajan these in the organic phases in the appalachians that also could have further reset zircons in generated to try to monetize so I break that up into separate cycle systems to weigh in to be and then.
Dave Moecher Univ. Kentucky: let's see, then, if we look at the thermal history of the appalachian based in central Kentucky this is modeling by Ryan thigpen.
Dave Moecher Univ. Kentucky: And What this shows is the thermal history during formation of the Basin and the maximum thermal conditions that could have been achieved in the base and without resetting those.
Dave Moecher Univ. Kentucky: mcconaughey ages and earlier paleozoic agents so some of the zero con in the details are kind of the base and was buried others others would have stayed close to the surface.
Dave Moecher Univ. Kentucky: So that they would have been likely recycle during additional recycling events, all the way through the rest of the mesozoic and into the Center zone.
Dave Moecher Univ. Kentucky: So that explains the reason why the zero con uranium lead and user Korean thorium helium ages are are so different Okay, why we have those large delta tease now if we get back to the carbon.
Dave Moecher Univ. Kentucky: Okay, the carbon is distinctly different it has a greater proportion of these older Paleo protozoa cages and it's got a substantial archaean component to it as well.
Dave Moecher Univ. Kentucky: And in fact in the corbin we found one to try to work on that was 3.8 billion years old, so.
Dave Moecher Univ. Kentucky: there's really a difference here that needs to be explained and to do that we're going to go pretty far afield here to look along strike in the appalachian basin in the late paleozoic where there might have been other.
Dave Moecher Univ. Kentucky: Other set of sedimentary sources or basement sources that have the ages that were interested in so here's the corbin and white.
Dave Moecher Univ. Kentucky: If you go to Scotland, there are three sequences the Torah dhoni in the morning and the Dell radian and then in Newfoundland there's also.
Dave Moecher Univ. Kentucky: neoproterozoic sediments as well, so those neoproterozoic sediments are chock full of these older Paleo protein protein result trains, now there are those Paleo protozoa trains in central there NGO, but the drainage systems systems would have been.
Dave Moecher Univ. Kentucky: longitudinal or transverse coming out of the appalachians and not coming off the cray time, so the reason why we look to Scotland, then, is we've got these these zircons of the appropriate composition.
Dave Moecher Univ. Kentucky: And those are the eastern granville terrains in eastern Canada, so the carbon could be viewed as a mix of recycled toward Ionian mining and Dell radian and and or some Newfoundland.
Dave Moecher Univ. Kentucky: sedimentary input, along with some transverse input from the southern appalachians so the model we're looking at here is, if we go back to the big pan continental river system.
Dave Moecher Univ. Kentucky: That toward donation mining and dial radian word would have been originally first cycle to Scotland Okay, so at the end of the paleozoic is approximately were Scotland was.
Dave Moecher Univ. Kentucky: They would have in the neoproterozoic those rocks would have been sourced from the eastern granville terrains.
Dave Moecher Univ. Kentucky: Then during the paleozoic and late paleozoic the sediment transport system that we're looking at here this big system of our turn grab.
Dave Moecher Univ. Kentucky: brought the sediments back and recycle the sediments back through the appalachian system and so here, we still have our transverse input and now we've got a longitudinal input that's bringing corbin like mature recycled corbin sediments into the south central appalachian basis.
Dave Moecher Univ. Kentucky: So.
Dave Moecher Univ. Kentucky: The titles are con as a soul proxy omits so much of the story now and I don't want to be a scold I want to encourage you go look at other systems us.
Dave Moecher Univ. Kentucky: find the Detroit mana sites they're not as abundant they're not as ubiquitous and they require more effort to concentrate the grains but grain for grain there's at least as powerful.
Dave Moecher Univ. Kentucky: Of a provenance proxy is zero con and a second or third to try to mineral proxy is really important for accurate provenance interpretations.
Dave Moecher Univ. Kentucky: And, as many have proposed recycling as an endemic process and process and Eastern lunching classic systems, and you have to consider that rebuilding building any drainage system.
Dave Moecher Univ. Kentucky: grendel's are cons have been recycled at least three times and some of them into the modern era might have been recycled, as many as eight times, through the fan resort so get out there and look for those mana sites, thank you.
Todd LaMaskin (he/him): All right, thank you Dave.
Todd LaMaskin (he/him): we're a bit over time, so if anybody has any questions for Dave you can post them in the chat or save them for later and we're gonna go ahead and move on to our next speaker.
Todd LaMaskin (he/him): So our next speaker is zach Yates, and the title of his talk is provenance of carboniferous cemetery rocks in the black warrior basin and allegheny unfolds rust belt Alabama USA so zach if you want to share your screen we're ready all right hang on just a second i'm.
going to pull my screen over here.
Zachary Yates: Yes, so thank you for the introduction Todd.
Zachary Yates: My name is Zack gates, and I am a master student at the University of Alabama i'm working on.
Zachary Yates: trying to get a better idea of the provenance of some carboniferous.
Todd LaMaskin (he/him): sedimentary rocks in the.
Zachary Yates: blackboard your basin.
Zachary Yates: Of Alabama was my screen sharing.
Todd LaMaskin (he/him): Sorry.
Zachary Yates: yep it looks good okay all right great um so yeah i'm trying to get a better idea of the provenance of sedimentary rocks in the black warrior basin and allegheny and full profile Alabama and.
Zachary Yates: I will give you guys a brief overview about why i'm doing it, and what it's about so.
Zachary Yates: In the last 50 years there have been at least 20 papers, published on set of my provenance and the black warrior Basin and the most recent was in 2020.
Zachary Yates: And of these studies, there are two primary hypotheses that are put forth those being that sentiment was derived from the a watch a tall origin.
Zachary Yates: And the southern appalachian origin to the southeast and the other hypotheses hypothesis is that these rocks were derived from a northern source.
Zachary Yates: With the sources being in the mid-continent region near lake Michigan and also in the appalachian origin, the northern northern appalachian origin, in particular so for the study area.
Zachary Yates: As you can see here, I have four locations highlighted, those being the black warrior Basin and the dark Gray.
Zachary Yates: The Cumberland plateau to the northeast of that, and then the.
Zachary Yates: And the pinstripes and look out so inclined to the far north east there in the hatch pattern.
Zachary Yates: With respect to the tectonic setting during carboniferous time it was pretty, as you can see, this is a pretty complicated tectonic setting with the allegheny and.
Zachary Yates: And a watch a tough thrust fronts converging in southeastern Lorenzo and so these these occurred simultaneously from Mississippi and into permian time.
Zachary Yates: So the carboniferous photography here in the black warrior Basin and the Cumberland plateau can be seen on the cross section in the bottom left corner this frame.
Zachary Yates: With the profile line a and, as you can see i've highlighted in different colors the formations of interest in life study, which include the park would formation.
Zachary Yates: Lower pottsville upper pottsville the hard sell sandstone and then the Pennington formation and the pottsville formation and then also to the southeast of the blackboard your base, and you have the.
Zachary Yates: And i've identified these two are i've isolated these two.
Zachary Yates: strat columns here that show the formations i'm looking at which include like in the black where you're based in the park would lower pottsville and Upper pottsville.
Zachary Yates: And in so in the lookout same client actually the Mississippi and classic strata is referred to as Pennington park what undifferentiated and above that you have pottsville like you see in the northeastern part of the state and the Cumberland plateau.
Zachary Yates: So these schematics that i've drawn here are.
Zachary Yates: Just rough diagrams that i've come up with to try to interpret and draw what the sediment distribution networks might have looked like at the time during the carboniferous period and there's so there's not much debate about.
Zachary Yates: The provenance of the upper pottsville lower pottsville or the pottsville formation in northeastern Alabama so i'll do away with those for now.
Zachary Yates: But, as you can see, the two provenance ideas are that the sentiment was sourced from the Northwest for the park would and hard sell sandstone.
Zachary Yates: And the other hypothesis is that it was sourced from the southwest for the park would and hard sell these interpretations are primarily.
Zachary Yates: There, at least the older interpretations from the 70s and 80s or based primarily on sandstone photography point counting faces assemblage and Paleo current data.
Zachary Yates: There have been a couple studies published recently that used to titles are con general chronology and these in these studies, they use a combination of details or country or chronology and X rf and.
Zachary Yates: sandstone photography to interpret provenance and their their hypotheses are that this park would in hard sell sandstone were source from the Northwest but their probability density plots.
Zachary Yates: They used TESS TESS for their products work on data, but as some studies have shown, like sailor on Sunday 2016 the chaos test P values tend to be too.
Zachary Yates: too specific, or to precise and.
Zachary Yates: Rejecting the null hypothesis that to.
Zachary Yates: set of samples resource from the same.
Zachary Yates: source So when I elected to do here is use a program called easy stats that was developed by Joel sailor and Kurt sandal in 2016 and so essentially.
Zachary Yates: What these these stats does is you put in two different details are con H distributions and it will generate an R squared value that will essentially tell you how similar the two distributions are to each other and I like to use probability density clients.
Zachary Yates: And so, essentially what the R squared values tell you the Cross correlation coefficients tell you is how similar the to probability density plots are or the.
Zachary Yates: The ages that are represented by the probability agency plots are and the differences in the peaks the shapes of the peaks the magnitude of the peaks.
Zachary Yates: So, if you look at these two are the plot on the left here What this shows you is at n equals 500 So if I have two samples with 500 Czar on ages.
Zachary Yates: And I want to figure out what my R squared value to add value is for those two samples or how similar they are.
Zachary Yates: It will plot on this line, and if it plots in the light Gray field, then that means your two samples are within the range of standard.
Zachary Yates: or within the range of variance for one population is a plus in the dark Gray field, and that means that it falls outside of the range of variants for the same population, and this was they use synthetic data data to come up with these values.
Zachary Yates: In matlab and so, if I compare southern appalachian and a watch a tall to try to work on age distributions I get an R squared value of about point eight seven and so these Let me be clear, these.
Zachary Yates: Southern appalachian and a watch twice distributions are from pre carboniferous strata from the appalachian mountains and watch a tall mountains.
Zachary Yates: And so, if I compare those my R squared value is R squared value is point eight seven, which is very high, and essentially indicates that these two.
Zachary Yates: distributions are statistically inside the range of variation for the same population and that they're they're nearly identical um if I look at the MID continent region.
Zachary Yates: You can see what the orange star so southern appalachian versus mid con and ages, I get a much different.
Zachary Yates: R squared value so point one, four, which is very low, and that indicates that it's outside of the range of variation for the same population so it's very unlikely that they were derived from the same sources.
Zachary Yates: So this is what i'm using to analyze my samples and so here in my study I have 15 samples 11, of which I collected and sent to the University of Arizona to have analyzed laser concert and for samples, which are from studies conducted in 2016 and 2020 by GL and different at out.
Zachary Yates: And so the smallest sample size, I had here was 234 grand so that was my of limiting factor here that was as low as I can go when sub sampling.
Zachary Yates: But these are my probability density plots these are so this is the data that found and, as you can see, it would be pretty difficult to visually analyze all of these and compare them and try to make inferences about the provenance so it's much, much easier.
Zachary Yates: To quantitatively analyze these these samples.
Zachary Yates: So here so Those were my samples and here are my potential source regions that i've chosen and many of these.
Zachary Yates: potential source region grains or ages are from.
Zachary Yates: were compiled by Piper and hepburn.
Zachary Yates: They had a really, really nice.
Zachary Yates: Publication where they compiled lots of details are on samples in ages from the appalachians and so i've used that in my study and i've also also use some other.
Zachary Yates: Studies from the mid-continent region in the watch and toss and the southern appalachians.
Zachary Yates: This this chart is pretty ugly and I don't want to make you guys look at it for too long, but it's right now it's the best way for me to represent what I have here.
Zachary Yates: But uh so Essentially, what I want to point out is that so i've compared my samples with the potential sources that I just showed you.
Zachary Yates: And first off, I want to talk about the two samples from Mississippi So those are portwood and the hartsdale sandstone and, if you look the the two lines on there, represent the cut offs for.
Zachary Yates: samples that could be statistically from the same population or from a different population, the plots above the top red line, then that means that.
Zachary Yates: They are statistically could be from the same population if it plots below the the bottom red line, and that means that they're likely from different populations, so what you see here is these two samples from Mississippi both.
Zachary Yates: are pretty similar to northern appalachian to travel, Sir Con H distributions and nothing else really comes close everything else kind of falls outside of the range of random variation for a single population, but if you look at all of the other samples from Alabama.
Zachary Yates: You can see that there are three potential sources that all kind of pop up pretty consistently in the same pattern, and those are central appalachian southern appalachian and watch a top potential sources.
Zachary Yates: And they all pretty much plot, with the same pattern, and also with a very high R squared value and so.
Zachary Yates: What that tells me is that not only are these samples similar to those but those samples are also there are those potential sources are also similar to each other.
Zachary Yates: And I think that's what the issue is here is there, too, similar to really be able to tease out the differences and the in the sources are the sediment the trial samples.
Zachary Yates: So my results.
Zachary Yates: Really, the big thing here are one of the big things is that the two samples from Mississippi so the park would and the heartfelt sandstone samples.
Zachary Yates: The R squared values for the northern appalachian strata here are pretty high so they fall within the random variation for the same population so they're most similar to northern appalachian source strata, whereas the central appalachian southern appalachian and a watch a toss data.
Zachary Yates: Generally fall below what would be expected for samples derived from the same population.
Zachary Yates: And second.
Zachary Yates: Here I have plotted the potential southern appalachian sources versus all of the other potential sources so.
Zachary Yates: The the orange.is southern appalachian and it's one because that's what it's it's being tested against and, as you can see, the central appalachian and a watchdog distributions are very similar to the southern appalachian distribution so that.
Zachary Yates: makes it really difficult to determine which of these was contributing to the.
Zachary Yates: sedimentary rocks in the black warrior base and an alligator and full rust belt during the carboniferous and so i'm going to have to do more work on that to try to tease out those details.
Zachary Yates: Another thing I wanted to bring up is the if you look back at these one of the provenance or the hypothesis is or hypotheses was that.
Zachary Yates: The sediment was coming from the mid-continent region of North America, so near lake Michigan and also the northern appalachians, but if you look at the mid-continent distribution.
Zachary Yates: Against the samples you see that it's has very little similarity so there's not much in common with what you see in the.
Zachary Yates: Black where your base these two black where you're based in samples and the mid-continent really, really, none of the black where you're based in samples share any are much similarity and similarity at all with the mid-continent source.
Zachary Yates: So, as far as my conclusions go the biggest things are the samples from Mississippi are quite different from what you see in Alabama the hard sell sandstone and park with formation in Mississippi.
Zachary Yates: fall within the range of variation for the northern appalachian appalachian sources but not the mid-continent sources.
Zachary Yates: And so, essentially this supports the hypothesis or these data, support the hypothesis that those two samples could have been sourced from a northern source.
Zachary Yates: But it doesn't give much support for the mid-continent hypothesis.
Zachary Yates: And then, for the rest of the samples, at least in Alabama.
Zachary Yates: The central appalachian southern appalachian and a watch a tall sources are very similar to each other, which makes it difficult to discern.
Zachary Yates: Which is most similar to the trial samples and so i'm going to have to do more work on these.
Zachary Yates: These data to try to tease out the details.
Zachary Yates: But with that i'd like to thank all of my funding sources my advisor Dr Dolores Robinson, my committee, Dr Joel sailor, my friends, and the everybody at the geological survey of Alabama and Arizona laser concept so and, with that i'll take any questions if anybody has any.
Todd LaMaskin (he/him): We have time does anybody have a question for zach.
Dave Moecher Univ. Kentucky: i'm going to ask it, it is bill Thomas isn't going to ask it.
Dave Moecher Univ. Kentucky: don't see I mean don't the Paleo currents all show that the sediments are coming out from the south and southeast.
Zachary Yates: So it depends on where you are, I think the me scroll up here, so the Paleo occurrence.
Zachary Yates: The Paleo current studies that i'm most familiar with are from.
Zachary Yates: The northeastern part of Alabama and the kava Sinclair room so up here in the northeast the Paleo occurrence.
Zachary Yates: David hobday in 1974 there's a study that shows that the Paleo comments down here are trending to the southwest.
Zachary Yates: Whereas, if you look kind of where the black warrior base and and Cumberland plateau meet in the black where you're based in these Paleo cards are kind of trending to the north northeast.
Zachary Yates: But the idea here is that the turtles are con gives you information on where the ultimate sources of the sediments or and with Paleo currents, I think there could be a lot of local variation that might not necessarily.
Zachary Yates: It takes I guess it would take a lot of Paleo current data to really.
Zachary Yates: nail down the provenance in a particular area and I haven't seen a great deal of Paleo current date i've seen some studies, but not, not a bond.
Thomas: This is built on us since they've asked where I didn't ask a question, simple answer is zach is going to be working with me this summer on another project and.
Thomas: i'm making a long list of things I want to talk about but.
Dave Moecher Univ. Kentucky: Then, and then he'll get the right answer.
Dave Moecher Univ. Kentucky: Sorry, and then he'll get the right answer.
Thomas: I think you'll figure it out yeah.
Zachary Yates: sounds good.
Todd LaMaskin (he/him): Alright, thanks everybody great talks.
Todd LaMaskin (he/him): we're right on time to head into our.
Todd LaMaskin (he/him): Next, talk at 525, and so our next speaker is Matthew mckay and the title of his talk is to try to work on uranium lead and thorium uranium, coupled with zero con uranium thorium helium reveals neo acadian uplift in the appalachian valley and rich.
Todd LaMaskin (he/him): And we can see your screen Matthew.
Todd LaMaskin (he/him): We cannot hear you Matthew.
mck11: How about now.
Todd LaMaskin (he/him): Yes, we can.
mck11: i'm sure i'll get a note from bill after this as well, so.
mck11: we'll just jump into it, so the study we're going to talk about today was a slightly different take on trying to sort out some of the carboniferous classic systems in Alabama.
mck11: And this was a between me and phil Jackson at memphis and a couple of my students and we collected samples over a large.
mck11: Area of the northern Alabama.
mck11: and the results are a little different than we initially anticipated on trying to hunt down and so we're going to talk about some of the implications.
mck11: On some of the kind of neo acadian transitioning to the allegheny and stuff which has been kind of a.
mck11: unwritten theme of the day i've seen a bunch of talks on that closing the gap between the neo acadian and the allegheny and and placing things in the middle.
mck11: And so brief introduction all those that kind of went over some of the stuff so i'll fly right through.
mck11: But the geology of Alabama is characterized by coastal planes down in the southwest portion of the state.
mck11: You have the Alabama valley and rich that comes through the the eastern portion of the state and then this is uncomfortable overland by the coastal plain settlements and then you have the black warrior basin located right in the northern portion of the state.
mck11: And then further towards the south kind of Central, Eastern Alabama, you have the Alabama Piedmont, which is the collection of metamorphic rocks in that location.
mck11: And so, a number of our samples come from the kind of central and eastern portion of the blackwater basin into the valley and rich.
mck11: And we're going to really focus in on talking about the hearts will sandstone in this talk, even though we have samples from another different other units.
mck11: But the heart soul is interpreted to be this Northwest southeast trending barrier island complex.
mck11: there's some back barrier features associated with some of the shales and it's also surrounded by this large carbonate bank to the north northeast that extends to the northern portions of of the black warrior basin from the Mon eagle limestone and the.
mck11: There we go the traditional interpretation on the the source of the sentiment into the black warrior.
mck11: has been from the southwest and bill worked on some of this for back in the 70s and 80s.
mck11: And, and then Steve brand and one of his his groups, they did some work also trying to link between the blackboard basin in the the our code base and watch toss sentiments.
mck11: And those pieces of evidence, are a you have this thickening classic which towards the southwest that that suggests input from the southwest.
mck11: linkage with the watches us to the West and and the appalachians come down here and then cut watch the top fabrics that are now lost beneath the.
mck11: Mississippi and payment, and so one interpretation, there is that the watch a toddler older, or at least predate most of these allegheny and appalachian structures that cut them later.
mck11: And so the age of defamation and the Alabama valley and rich becomes pretty important if you're looking at sediment in the adjacent basin.
mck11: You know, an easy interpretation will be you take sentiment from the valley and rich and dump it into the black warrior this right there.
mck11: But the problem with that is that you have Pennsylvania in San stones that are included in a sequence of fold and fault structures and if you track some of the structures.
mck11: here's some folding near Chandler mountain cut by a fall, therefore, the faulting has to post a folding and if you track some of these back there's the halina fault that halina thought tracks around and is cut by the coosa fall.
mck11: And so the sequence of events and they characterize a hinterland breaking defamation sequence, therefore.
mck11: The easy interpretation, there is that all of these structures are Pennsylvania or later the heart souls Mississippi and that predates it So how could you be uplifting valley and rich settlement and dumping in the end Jason basin if there's no value in rich structures at that time.
mck11: So the.
mck11: kind of developed interpretation that's coming from the southwest which the watch it, as do predate the Pennsylvania structures in the elegant in the appalachian.
mck11: valley and rich, so the interpretation from the southwest is also based on the occurrence of large fossil logs.
mck11: bill has directly told us about this, this is, this is also Thomas many personal communications.
mck11: about the logs that are located in the heart, so you find these giant log sets big masses of logs and so that suggests that more proximal location is down to the south and potentially down here to the southeast.
mck11: And so that all kind of holds from a South Western south or South Western source for the heart soul and other classic rocks in the mississippian.
mck11: With the kind of details are con revolution and i'm really glad to go after Dave smoker because he always has a really good message about.
mck11: The recycling hazards that we we better repeating the classic record or the tribal record and and and I have a little bit to throw in that on that as well, so on.
mck11: The DC interpretations have gone in and looked at, where are these details are con that we're seeing in the black warrior and then where can we directly source them from.
mck11: And so, a couple studies have come out and they found 1.7 1.8 billion year old desert con so they try to directly source those from like the ancestral rocky mountain regions, where you get 1.7 gaba pi miles it's all ages or.
mck11: You get 2.5 2.7 billion year old superior green so they they tried to directly source those in the Mississippi and.
mck11: But the hazard there becomes the recycling that Dave talked about is those rocks have been sitting around for one or 2 billion years and they could have been recycled back and forth against across many continental drainage systems.
mck11: And so that interpretation may have some problems if we're relying entirely on uranium LEDs are con.
mck11: So the desert populations were used to infer this large continental drainage system tapping Western sources.
mck11: Some northern appalachian sources through the mid-continent down this kind of complex drainage, and that does have some problems if if the sediment sources are coming in from the southwest how are you bringing in sediment from the do north, that is, that that is.
mck11: in direct conflict.
mck11: The lack of leafy Greens was also used to suggest long distance transport.
mck11: And then the presence of trace metamorphic minerals which i'll go ahead and tell you that every metamorphic mineral that's been found in almost all these Mississippi and in Pennsylvania strata can be found.
mck11: Within a one or two hour drive of some of these samples in the appalachian Piedmont.
mck11: And so, these these two interpretations are in in just incompatible with each other, so we start about trying to dive in and find a solution that honors the strata graphic and well log based observations.
mck11: Of Southwest or westerly source and then kind of make it tie with these uranium lead populations that we're seeing.
mck11: And so, our samples come from the the southeastern most extent of the hearts will sandstone we also grabbed a few pottsville say samples as well.
mck11: But what we did a little different is we went into the valley and rich and we started sampling the cambrian and ordovician strata.
mck11: And, along with a couple of brute blue Ridge samples, for the most part, we were able to get some blue Ridge data.
mck11: Uranium LEDs are con data from some other sources, so we didn't have to necessarily date all those ourselves, but we did get a few that we didn't have data for like the CIO courtside some lay damn classic stuff but.
mck11: And I guess in a kind of straightforward, since we tried to do source to sync can we source these their COMP populations locally, at least in the rocks exposed now You might ask why didn't you get stuff from the watch and taz.
mck11: Well, the sector of the watch that would be just a Jason is under the Mississippi and payment and so we're using these samples is not only a direct.
mck11: investigation of the valley and rich in Alabama sector but also potentially a proxy for what's kind of around the bend in the watch a toss sector.
mck11: And so, for starters just kind of the eye test you look at the blue Ridge rocks of North Carolina in the inner Piedmont Western Piedmont.
mck11: Eastern Piedmont of Alabama Western blue Ridge that'd be the talladega belt and some of the other rocks in there.
mck11: And you start comparing those two to watch a tas and the Pennsylvania, and you have some major source problems in here, first of all, everything has greenville.
mck11: I wish I could remember the bill quote about grenville means that you're basically on the planet Earth, I believe, is the quote about the granville so brando is just everywhere.
mck11: Other than that, a lot of these other populations just don't even they don't even match the eye test there's a small amount of this kind of mid continental brown Granite realize.
mck11: they're missing some of those 1.7 1.8 billion year old grains entirely they don't have any of the superior age grains that we would expect if they're sourcing some of these material and then.
mck11: In the paleozoic content they have to Connor ages, whereas if you look in the Pennsylvania, and the Mississippi and which includes our hearts Plus we took some data from gifford it out.
mck11: Over in Mississippi to give us a little bit of spatial distribution, so we have these early celeriac kind of early.
mck11: Early acadian I guess ages that you'd see in those are just not really compatible with the bulk of ages observed in the blue Ridge.
mck11: And so, then we tie that in and started looking will slip directly in the paleozoic valley and rich strata that are beneath the of the carboniferous and if we start looking just passing the eye test we do have superior con.
mck11: con age populations, because there have been multiple sediment systems that have brought that that sediment from the north down into some of the cambrian or division and devonian rocks.
mck11: There are yavapai closets all age populations, we have those mid-continent great right light populations kind of scattered in there and variable concentrations and then we have greenville again that's not.
mck11: super distinctive but everything's got grenville um so we have everything, but this young population of for 20 ma grains.
mck11: And we can locally account for those right adjacent to our source, so we started looking and.
mck11: Some of the mid to large drainage interpretations.
mck11: have looked up in maine to bring sediment down well, the problem with, that is, you will not only get the 415 ma grains that are present up in maine.
mck11: You should get to college age material and a bunch of other material that that is also present up there it's not a selective system, you should get this large amount of.
mck11: Age distribution and that's not what we see we see this really kind of moderately isolated for 20 ma for 15 am a population.
mck11: And so, some plate reconstructions will show you that the yucatan is getting real close to the southern or Southwestern extent of the black warrior basin in the early mississippian.
mck11: And so we investigated really quickly there's not a lot of exposure, but the two exposures the Maya mountains have early solarium pollutants that are the exact right age.
mck11: there's also some data new data from the chicks live impact that exposes some of the basement rocks, and so we were able to pull some of that chicks live data.
mck11: and see that the age spectrum that we are seeing in our black warrior base and and pottsville rocks from that kind of for 20 ma population.
mck11: is nearly identical in span to the data from the chicks eliminates very isolated data, but that does at least give us him 10 portal range that kind of matches to at least account for a entirely Southwestern drainage.
mck11: And so we have these different things that we wanted to see Can we just model, these can we get a model to come back and take these different things we're going to throw.
mck11: Our cumulative blue Ridge in there we're going to take that chicks elude data we're going to take our cambrian strata, which is the chill how a group so that's large spatial distribution of the chill howie ordovician would have been the cold mountain.
mck11: And some devonian rocks can we mix all these together in some sort of proportion and replicate what we're seeing in the Mississippi and heart soul Yet is it coming from the North or can it be locally sourced because if it's locally sourced than our Southwest drainage interpretation.
mck11: From from bill back in the 70s and steep grant that still holds and when we were running our DC mix models which is similar system to what zach used.
mck11: makes it got a really good correlation from and we have very little data on the data, the distribution of certain populations and say the cambrian waste and notice the Cambridge wildly variable depending on where you are so we only have a small.
mck11: understanding of how variable some of these units are, but we still were able to get a.
mck11: Cross correlation coefficient of point eight five which again i'm glad that zach did that Nice correlation rundown point eight five is a very high cross correlation coefficient for just a bunch of stuff We talked in there, to try to account for local sourcing.
mck11: And the models predict a number of things one they predict no blue Ridge, they need no blue Ridge to come out with a best fit model.
mck11: And they only need small amounts of that chicks live to account for those those early slurry and ages, but majority of what is predicting our recycling of the paleozoic strata that are beneath.
mck11: And so, remember that throw some problems out there, because the defamation is inferred to be Pennsylvania or later we have a Mississippi and sandstone So how do we rectify these problems.
mck11: And one of our kind of initial thoughts was you know how do you even if you are bringing it from the the Alabama valley and rich, how do you take it down and then route it in from the southwest.
mck11: Well, the good analog, and this is actually so granted out 76 use this analog for the blackboard basin would be the Bingo.
mck11: Himalayan system where you're able to take sentiment routed through the syntax this and then dump it into the basin and that that model kind of works.
mck11: So account for the direction if we've got the components in the southern appalachian or in the watchdog's you funnel sediment.
mck11: into the syntax this and then dump it into the basin, and that would account for sediment coming from the southwest.
mck11: The other component was the compositional maturity well the call the call the mountain and the chill howie and the devonian said sediments that we used are all effectively courts era nice there's a little bit of.
mck11: felt Spar and some of the units, but they're they're already composition compositionally mature, so you recycle compositionally mature sands you're just going to get compositionally mature sand.
mck11: So.
mck11: If that's our model if we've got seven that being sourced either on the watch itself side or the appalachian side they probably have similar lower paleozoic strata.
mck11: we're bringing it in mixing a small amount of that yucca tap material and dumping it into the basin in.
mck11: that's that's that's a model, and that does fit at least the uranium lead and it definitely fits the strategic information.
mck11: The problem again becomes the timing of uplift, how do you uplift paleozoic rocks that don't apparently undergo defamation until the Pennsylvania to source a Mississippi and sand.
mck11: So to answer that we tried to rely on helium uranium thorium helium dating of.
mck11: several different units and i'm going to talk about to really quick, so we dated five to six grams per sample.
mck11: We were unable to get large enough grains out of the Mississippi, and so we had to go to the Pennsylvania, where everything's a little coarser, but we did get grains out of the cambrian chill howie.
mck11: And what's very interesting is, if you look at remember to Cambridge and sandstone it contains earliest Mississippi and or even maybe late devonian cooling ages in the the cambrian sandstone so those represent thermal resetting and.
mck11: When a couple brains were not even entirely reset so we buried these right within the partial retention zone, and then we zoomed him to cool everything off.
mck11: And we were able to get very similar results from Pennsylvania in San stones very nearby.
mck11: And so that alone right there is interesting, the Pennsylvania sandstone that's the trial right 353 40 ma grains or to try to getting Washington to the Pennsylvania sands, but the cambrian.
mck11: In the Alabama value Ridge being cooled between 350 and 340 well that's big that suggests something significantly different, and the sample we pulled this from a wiser mountain right up here in involved in this.
mck11: mess of thrust faults, but if you look down here you have very little in fact this unit here is not inserted graphic continuity with anything younger than Mississippi and above it.
mck11: So there's no reason to think that that couldn't have been deformed prior and then read a form or false been reactivated in the mississippian.
mck11: and were able to take multiple grains and move them into the hefty program to just try to get a little bit of a better thermal model.
mck11: And we were able to get very similar thermal models based on those helium ages, where you have cooling starting about 373 60 and rapid cooling up until the.
mck11: Well into the middle mississippian which he is is consistent with some of these rocks in the Alabama valley and rich undergoing a neo acadian defamation pays phase.
mck11: And that is that does conflict with the Cross cutting relationships, but not if you consider reactivation of faults in the Pennsylvania permian to get that later structural framework that we're making those interpretations on and so.
mck11: You know, with with all that kind of piece together, we were able to come up with something that at least accounts for all the uranium lead signatures that we see a.
mck11: b it does satisfy a lot of this this strata graphic information that has been compiled over the year so that fits as well for the Mississippi and strata in the black warrior.
mck11: And then, be it kind of pushed us on to this other bit of data, where we think we're seeing a neo acadian sliver of a fold belt that's been reactivated and real incorporated into the allegheny and fulton thrust bill.
mck11: Again, so many talks on this shrinking the difference between those two, so I would highly recommend people go check out some of the other ones.
mck11: Thank you.
Todd LaMaskin (he/him): All right, thank you matt um it looks like we're over time, so if anybody has any questions, we can save them for later and we'll get on to our next speaker.
Todd LaMaskin (he/him): At 545 our speaker is Sharif moose Doc and the title of his talk is provenance variation and promote carboniferous solicit classic sequences from Central Eastern Indian platform.
Sharif Mustaque: hi Todd.
Sharif Mustaque: thanks for the introduction.
Sharif Mustaque: Can you see my screen.
Todd LaMaskin (he/him): We cannot we still see matt screen, but it just changed.
Sharif Mustaque: Okay.
Todd LaMaskin (he/him): Coming up.
Todd LaMaskin (he/him): Great yeah.
Sharif Mustaque: And you can see the pointer.
Sharif Mustaque: Sir Okay, thank you hi everyone today my talk is about the provenance variation in Parma carboniferous silly sweet classic sequences from Central Eastern Indian platform i'm sure you can stock and my co authors are the tourist trap with Dean, and not really see haines from auburn university.
Sharif Mustaque: So i'll start the chalk, with a brief introduction about garner and now the last known super cheering.
Sharif Mustaque: that existed throughout the paleozoic and then i'll go into the methods and results continued into discussion and finally into conclusion.
Sharif Mustaque: The map that you see over here is the is from grey at all from 2007 and it shows the entire gone on on.
Sharif Mustaque: super terrain, where they are broadly divided into different portions the eastern part is shaded is shown here in yellow color, whereas the western part is shown in the scion color.
Sharif Mustaque: As well as we can see some of the origins throughout the entire paleozoic that form in and around gone on.
Sharif Mustaque: Now our study this study focuses on the Indian platform were gone on bases are located and shown here in the red shirt shades.
Sharif Mustaque: And the study area that we focus on is shown in the yellow box is the basis of interests are shown in the yellow boxes.
Sharif Mustaque: And throughout this entire time God run basins were supposed to.
Sharif Mustaque: go through different climate change and sedimentary that triggered sediment deposition and eventually control the different type of statements that were being deposited in these patients.
Sharif Mustaque: By a due to reveal dynamics to outdoor changing climate.
Sharif Mustaque: Now, on that note this figure is actually from raggle at all 2008 where they showed the magnitude of your state extreme level fluctuation due to glacial and interglacial periods throughout the.
Sharif Mustaque: Farm carboniferous the interest here is this box over here shaded in yellow wait there shows three specific.
Sharif Mustaque: Policies of glacial and interglacial period that continued through our department carboniferous where glacial periods are shown in Gray and intellectual periods are shown in white.
Sharif Mustaque: Now this fluctuation of glacial and interglacial cycle actually triggered formation of bases in in the Indian platform.
Sharif Mustaque: The figure on the Left actually gives you an idea where glaciation as glaciation progress vertical stress by ice cost crystal information and, as these glaciers melt they react as glacial ice ice illustrated rebound forming river valleys and eventually evolving them into reef basis.
Sharif Mustaque: On the right hand side, we see a schematic figure showing the same thing as the bases were being formed simultaneous with the same intensity remains being deposited in these bases throughout the Parma carboniferous time period.
Sharif Mustaque: Now, looking at the different bases here is a static graphic for me here is the table for sharing of information between different bases in the Indian platform.
Sharif Mustaque: point to be noted here is where it says not Western Bangladesh it actually is representing the same Eastern Indian platform, whereas the rest of the ones are indicating what central Indian platform and they are all labeled in the insight map, based on the numerical values.
Sharif Mustaque: Going into a bit more detail here is a little little logical columns for different bases that we have sampled from, and you can also see the sample locations in these areas.
Sharif Mustaque: One thing to note in all of these bases is throughout the entire condo and.
Sharif Mustaque: basins during the Parma carboniferous the sequences started with a glazier Jenny compliment to damage deposit.
Sharif Mustaque: And was overlaid by coarse grain crops to medium grain sandstone and in this study, we will treat those as Lord God or and sequence.
Sharif Mustaque: followed by that we have medium to find grain sandstone alternating with matt stone and cold layers and those would be considered as upper godwin sequences and again the inset map shows the either basins in eastern Indian platform and central Indian platform in the area.
Sharif Mustaque: Now we started with studying in sections made out of sand stones and conglomerates, the first six the first two rows show.
Sharif Mustaque: samples from eastern Indian platform and the bottom row shoes samples from central central Indian platform and we can see that most of our segments are rich in quartz and phil's parts.
Sharif Mustaque: Were with clay matrix where, as there is a significant increase of volcanic an igneous and metamorphic latex in the column a column at layers that we have studied.
Sharif Mustaque: Continuing on that note we analyze we studied at least 350 grains from each of the samples to get the sense to study sandstone photography and they were plotted here in different tiny diagrams.
Sharif Mustaque: On the left side, we see the turning diagram, of course, plus shirt fells point analytic fragments by Meg breach which shows a sandstone composition.
Sharif Mustaque: And, based on the data that we have studied our sandstone fall under some articles to slicks of articles type and they were also compared with previous studies done on other basins and other locations from the Indian platform on the right hand side, we have the beautiful diagram to.
Sharif Mustaque: study the tectonic environment tectonic setting of the source rain and most of our samples fall under recycle origin exciting with some of them going into transitional continental setting.
Sharif Mustaque: Following that we studied the heavy minerals, from all the samples, and they are presented here in different plots the one on top over here is the garnet population percentage from different bases.
Sharif Mustaque: Where the green bar green ones are from eastern Indian platform and the red ones are from central Indian platform.
Sharif Mustaque: Z consumer in and routine percentages from each of these bases and then on the very bottom left, we have the appetite to merlin versus routines ECON indices.
Sharif Mustaque: and appetite to merlin versus garnets ECON indices the takeaway from here, we will analysis that we have observed, is the upper corner and sediments have a higher population of the country million rule.
Sharif Mustaque: And a lower population of garnet, whereas the lower corner and segments are totally opposite they have low low population of tr and high population of garnet.
Sharif Mustaque: This triggered us with the idea that, obviously, there is a change in provenance bit in between the lower and upper gone down and sequences.
Sharif Mustaque: On that note, we continued with electron microscope analysis for studying garnet composition that were done in auburn electron microscope lab here in auburn university.
Sharif Mustaque: We studied, a total of approximately 200 plus grains of garnet from different teams sections of heavy minerals and we plotted them in the turn any diagram to see which type of.
Sharif Mustaque: compositional group the garnets fall into, and we can see that they are most of our garnets that we studied are rich in iron Type one team type garnets.
Sharif Mustaque: Though we have some other ones with there is a compositional very mixture of different types and, for example, we have one that actually falls into spirits specificity and gross hula types, so we.
Sharif Mustaque: separated those two out and we figured out that there is what only one garnet green that we found out that was rich in calcium.
Sharif Mustaque: calcium.
Sharif Mustaque: The next thing was to plot them to identify which type of metamorphic faces or terrain, they after the show affinity to.
Sharif Mustaque: On the left hand side, we can see, most of our samples to an afternoon at 2am people light and random like fishes with some exceptions.
Sharif Mustaque: And on the right hand right hand side in this journey of your diagram, we can also see that they show again the panel like patients affinity with some of them showing pigment it too low grade metamorphic possibly possible avenue.
Sharif Mustaque: Now, on after that whole rock geochemistry was performed on all the on samples and based on whole rock geochemistry the sandstone compositions indicate that they are highly Fitzpatrick sandstone with some that falls in becky too late at night and articles in compensation.
Sharif Mustaque: On the right hand side top we have the major upsides plot shown and that indicates that our upper gone on sequences for both from central and eastern India Indian platform are.
Sharif Mustaque: definitely have a deficiency in sodium oxide, whereas the lower gander and sequences true they are high in sodium oxide and also again they show mixture of different type of oxides coming down.
Sharif Mustaque: The rare art element pattern shows a similar patterns throughout the.
Sharif Mustaque: Both upper and lower gone on and sequences but one of the thing to note here is the lower gone down and sequences both in Central and Eastern Indian platform have a higher concentration of rare elements, then the upper gone on and sequences.
Sharif Mustaque: So we tried to study the weathering penetration and whether intensity of weathering and alteration in the sediments so we plotted the ASEAN cater any diagram.
Sharif Mustaque: And look at our samples, which can be seen here and they were compared again against standards of post archaea and Australia and shell.
Sharif Mustaque: upper continental crust and not American shale composite on the right hand side we calculated the chemical index of alteration that is presented here for the different samples that we studied.
Sharif Mustaque: And more most of our samples show a medium degree of alteration, but there are some which are less or more than that of alteration.
Sharif Mustaque: now hold on geochemistry can also be used to study source range types and possible rock types and, as we have.
Sharif Mustaque: shown earlier, that there is a possibility of igneous sorcery and mixing we want to emphasize on that note, so what we started with is plotting the.
Sharif Mustaque: lithium thorium and scandium ternary diagram and plotted our samples in that, compared with the past UCC and nfc and all of a mode majority of our samples show they fall under continental island architectonic setting.
Sharif Mustaque: When Claudia under potassium over sodium by silicon dioxide, we see that the lower Gordon samples are more of a show more affinity to active continental margin.
Sharif Mustaque: Whereas the upper conference samples show affinity to passive margin so here is a difference in setting tectonic setting that is clearly visible between the lower and upper governance sequences.
Sharif Mustaque: When titanium oxide versus the cornea was plotted we see that there is a possibility of mixing from both failed sick and intermediate igneous so students.
Sharif Mustaque: And this suggest this supports our idea cause the bedrocks that we have in those areas, those are intermediate igneous in composition.
Sharif Mustaque: And finally, we plotted the discriminate calculated and cloud at the description and function.
Sharif Mustaque: For the sediment samples, and here again we can see, they have affinity to feel sick igneous provenance three intermediary igneous provenance.
Sharif Mustaque: But the change here is there are some upper ghandour and samples from central India, which fall under may pick igneous provenance and we suggest that this might be due to the due to the influence of.
Sharif Mustaque: intrusion may freak intrusions that little awkward later during the permian in the central Indian platform.
Sharif Mustaque: Now to summarize gone down and the map over here is after weaver's at all 2018 and where he.
Sharif Mustaque: showed different sermon disposal networks throughout the eastern gondwana carrying both glacial and flew all flows.
Sharif Mustaque: And he suggested that the bases in Indian platform where initially formed as a single major basin.
Sharif Mustaque: That eventually got separated into different smaller basins through later in geologic time but we contradict with that idea, saying that.
Sharif Mustaque: Our study indicate that, rather than being one single base in this individual basis form simultaneously throughout the Indian platform.
Sharif Mustaque: Technological data indicate that our local governance elements are a bit less mess year compared to our upper continents elements.
Sharif Mustaque: The heavy middle population also indicate possible change in store students, where we can see that one of the lower corner and sequences are rich incarnate, whereas the upper corner and sequences are deprived of that.
Sharif Mustaque: guarded composition and population again also suggested that idea that they are mixing from multiple type of source rains and.
Sharif Mustaque: Whole rock geochemistry finally been indicate that the possibility of type of igneous source students were feel sick and intermediate and to sum up.
Sharif Mustaque: Governance elements that we studied definitely show variation between carboniferous which are long gone Ronan and permian which are upper corner and sediments.
Sharif Mustaque: retro graphic analysis indicate majority of the samples came from recycle origin source setting heaven menial data in and.
Sharif Mustaque: garner composition data indicates, there is variability between the lower and upper sequences were gathered composition indicate mixture of MTV light and ground like fishes and.
Sharif Mustaque: Whole rock geochemistry indicate lower gunner and settlements have affinity to active margin say.
Sharif Mustaque: Active Martine setting, whereas upper corner and say dementia, for you to pass it Martin setting and we conclude our presentation, with the idea that this.
Sharif Mustaque: This is entirely due to the climatic variation or the glacial interglacial pulses that happened throughout the Parma carboniferous that triggered this variation of segments in this basis.
Sharif Mustaque: So I would like to thank the different organized organizations that supported this research, and obviously auburn university electron micro programs is lab to support our electron microscope and.
Sharif Mustaque: Thank you, and any questions.
Todd LaMaskin (he/him): We have time for questions if anybody has a question for Sharif.
Todd LaMaskin (he/him): Alright, well, thank you cheri for interesting presentation.
Todd LaMaskin (he/him): So it looks like we have a couple of minutes but i'm wondering if we shouldn't go ahead and get started, I have a feeling that most people are sticking around for this last talk rather than coming in at the last minute.
Todd LaMaskin (he/him): gave, what do you think.
Dave Blake: probably a good idea, great.
Todd LaMaskin (he/him): So our next speaker is Ashraf udine and the title of his talk is the title uranium lead and argon 4039 constraints on exclamation history of the eastern Himalaya and the Assam Bengal system.
Ashraf Uddin: Hello everybody good afternoon you guys see the slide.
Todd LaMaskin (he/him): Yes, we can you're all set.
Ashraf Uddin: Okay, thank you, this is a continuation of workers they.
Ashraf Uddin: brought up there.
Ashraf Uddin: We have been working on the Himalayan front for a couple of decades, if not more.
Ashraf Uddin: And then recently two projects over in the appalachian so.
Ashraf Uddin: Several years ago I had an opportunity to work with.
Ashraf Uddin: Several.
Ashraf Uddin: You know, Dr criminologists and then one of them was Sam boring, and this is a type of the word, this is the work that we actually did together some years ago, and he.
Ashraf Uddin: You know I wanted to include him as a co author here but.
Ashraf Uddin: This is him.
Ashraf Uddin: he's not living anymore, so I couldn't add him as a court.
Ashraf Uddin: But this talk talks about.
Ashraf Uddin: Of course, the composition, that we have been studying over in the Himalayan from the stimulant drastic ways, yes, and then built into the boat uranium lead on this are cons and are going are going on Moscow slides, and so the.
Ashraf Uddin: buildings is a Co author with with us and the people most of these are the modern work and the other gentleman is jurgen Sharma he's a.
Ashraf Uddin: gentleman from deep regarding diversity in our song he taught me the geology via I would not know anything so I spent a lot of time with TIM learning each bed his location.
Ashraf Uddin: So there are a few others to complement our Clark bots will always helped me with ideas suggestions we drew proposals actually the out.
Ashraf Uddin: The initial stage of a proposal on a napkin GSA I remember it guys Men still helping us, and why not is Professor ducking diversity.
Ashraf Uddin: Is within the framework there and few students, there are several students to be commented here, but these three actually work directly on the presentation that I have, and of course the nsf GSA box, does the petroleum companies also help so first slide would go with.
Ashraf Uddin: The location, overall, and this is by the way, most of the talks that I heard from ADM today is here in the western hemisphere so Sharif and I took the chance and the weird thing we can very bold, to talk about in the eastern hemisphere.
Ashraf Uddin: But the utility of doing something in the.
Ashraf Uddin: Himalayas was that this is a recent thing happening and we can actually learn.
Ashraf Uddin: Some of the things that happening today, like the flow of the channels, how we were serving shifted how.
Ashraf Uddin: They have gone in a longer today no turning to transport systems, so all could be learned in the modern day system in the Himalayas and then.
Ashraf Uddin: You could be can be utilized and that's what we have been doing over in the appalachian so Himalayas in the east, west, there are several little tectonic belts and he's each are bonded by a trust belt and so and that there is a black line up there.
Ashraf Uddin: Is the is the apocalyptic belts, that the future and on on this front, we have to do such bells in the in the barn ranges so most of the focus of this study is on this.
Ashraf Uddin: In the ganja the plane, right here in the basin, but you know a lot of work has been done on the symbolic same thing, most of you probably know about that.
Ashraf Uddin: Still still popular for many you know fossils vertebrate paleontology yes or less magnitude strategic is very popular place to work.
Ashraf Uddin: So this is the Indian Shell and down there, there are a bunch of real wealth and.
Ashraf Uddin: A lot of the data that we know about the erosion and and roofing of the Himalayas came from those big old fans settlements and the real sentiments.
Ashraf Uddin: So that's the work is focused right here in the northeastern part there is a place kolesov and then there are these three ones are like a plateaus and then this is another base in so let's go into the next.
Ashraf Uddin: Cross section to show you where we are so here we have you're not South cross section.
Ashraf Uddin: Everest down and then going down there, what I am showing here for is this sudden drop off EC 20 kilometers so sediment that's huge.
Ashraf Uddin: You know, probably, you know the appalachian had these things during your primetime.
Ashraf Uddin: And this is a lot south and east, west, we have the Indian shield Indian krypton lot of block faults and she leaves talking soon as one of them on on one of these extension raisins and then goes down here we have this in the barman ranges right there is kind of.
Ashraf Uddin: creeping in, inside and there is a transform fall that we suspect is their current fault, so that actually plays a major role in in shaping the mechanics of that area, these days, so.
Ashraf Uddin: With that note let's go to the first the Northeast this is in a song so here is a cross section between the Himalayas and the Northwest and the environment, the southeast and.
Ashraf Uddin: it's like this is the area somewhere in the middle, is the shipping belt shipping Valdez is is a downtown block right there it's founded by two thrusts.
Ashraf Uddin: dicing another trust and most of the settings that we collected already in a song are located in these areas, by the way, if you recall that the.
Ashraf Uddin: First, petroleum in the eastern hemisphere were found close to the various in the boy, so we have the strategic phaedra it will seen through pleistocene all are found in these areas.
Ashraf Uddin: And so we zoom in to go detail on on what we're talking about, so we have three different lobes of data Center that will be talking about.
Ashraf Uddin: One is right there in the song, then the following one is in pretty close to the plateau week sometime called shillong or lower a song, this is upper Assam and that's the Bengal basin popularly.
Ashraf Uddin: known as sil a trough in this case, and so we we discuss the strategic view of this area, and then provenance information based on compositional data and Detroit on to chronology beta so looking at the strategic fit from northeast on the right hand side to Southwest.
Ashraf Uddin: When you look at it is dominant the classic with little bit of our cabinets in the in the Center column in the Left column, so the shillong area and the limestone is limited limestone.
Ashraf Uddin: Is this one of the market bid in that non-fossil the furnace mason permanently, if not a normal new lights, so one of the interesting thing to note note here that the Paleo gene thicknesses.
Ashraf Uddin: Here you're seeing an allegation thicknesses decrease towards Southwest So if you picture that the Himalayas standing close to these areas first.
Ashraf Uddin: got his deposition during the alley you'll see an analogous in time during the period it and this frog has been migrating toward South Southwest so the.
Ashraf Uddin: The younger eunice miles scene and angry, Mr much thicker in the Southwestern mason in Bengal racing this, that is the most recent data Center before the big fan.
Ashraf Uddin: So looking exposed stratigraphy the yellow.is in Assam this one is in shillong and the Green one is in Bengal racing, so this is a thinly better.
Ashraf Uddin: sandstorms these are millions and stones ever seen, and that one is silty shane's sent.
Ashraf Uddin: sandstone partly and there is a dark layer of shane down there mud rock and then this one, the warning that Bingo basin is pretty weather.
Ashraf Uddin: But nevertheless, we got the samples that we needed for our analyses, so we look at the composition of the same three areas cinnamon composition now for the macro graphs, so this is late at night.
Ashraf Uddin: or fill out an idea, a lot of Moscow whites in there and little fragments and I did not pick a good sample right here, but this is later tonight and kind of it's difficult to distinguish this this one.
Ashraf Uddin: This one, however, the one in the Bingo basin is the Hollywood scene is sharply different it was in analogous in a different, they are course those was there a night with solving doula and.
Ashraf Uddin: Like hardly any little fragments or nfl sports presenting the sentence, so are you know this period in time.
Ashraf Uddin: The sources of these three basics are different that's what we aim in fighting right here, from the very beginning.
Ashraf Uddin: Then, when you plot in dickinson's provenance fields, so the being all basin is up there, and a some just opinions in plot, this is not so i'm dealing with this one and that one right there, so these two are different so again inference is that.
Ashraf Uddin: How sources are somewhat different for being always in a song, so we look up the street, he gave he go up to kneel gene and again the same three areas.
Ashraf Uddin: Some shillong and and then that the Bengal basin, in reality, right so in theory it's difficult to distinguish the composition.
Ashraf Uddin: They pretty much look alike, and so, when far that in the nickelodeon time probably this whole these three data centers are deriving material from a rotten egg sources and the miles in time there are authentic sources did not establish for the innovation.
Ashraf Uddin: right that note let's do the Nielsen plot, so this is our Bengal racing and we have a new news otter at the bengals fan is also there are number five is the Bengal fence to all kind of plot in the similar areas, and this is a sum up there, and they are quite different from.
Ashraf Uddin: The single racing sentiments, at least the six number six is somewhat very different in competition.
Ashraf Uddin: We look at some major element chemistry few miles in time, so we picked up the samples, which are called pre mapping all three miles in and are some pre miles in and see the difference here their plot differently, as the composition instructed or suggested in the previous few slides.
Ashraf Uddin: We look at trace element chemistry similar way that sample your team.
Ashraf Uddin: Is is different kind of sitting outside compared to the other samples that you might have seen and the younger sediments in that area.
Ashraf Uddin: And then regional Spinelli chemistry, we did on the samples and titanium oxide percentage what percentage that some base in the one for the Northeast.
Ashraf Uddin: is less than Point five and probable source of your lights to sitting not very far from there and then all samples, however, there was a data point we tie and.
Ashraf Uddin: I remember that I was discussing with Steve kish who passed away at Florida state and he said that he hardly saw in in plots like that.
Ashraf Uddin: So this could be from Arad mahal connects is in eastern India that could be a potential source for it, or the Tibetan areas that we worked on in southern Tibet, and that they have also.
Ashraf Uddin: More than one point or titanium with percentage So the message from this slide some samples probably had uniform source, but the bengals samples readied.
Ashraf Uddin: During for at least for titanium contents.
Ashraf Uddin: provenance fields, this is the discriminate functionalities so most of the.
Ashraf Uddin: Assam three miles in sediments they are here they are intermediate and mythic provenance and the younger ones are plotting out there in the quarter sedimentary problems.
Ashraf Uddin: So what we know so far that the Bingo hall and song, they are different in terms of.
Ashraf Uddin: sentiment composition your chemistry and the neo gene sequences seem to be similar not identical, but similar.
Ashraf Uddin: So what we are showing here some detailed here chronology data to make sense, about what we found from composition and to chemistry so sample, so this is a busy map just prepared it.
Ashraf Uddin: few minutes ago, so we have collected Czar con samples from some areas and some of us will be more seriously collected masquerade samples.
Ashraf Uddin: So the shillong areas, the one in the middle, we did not collect any zircon samples, yet we are working on it, so the project is ongoing and several are real core samples, and some are outcrop samples so let's look at what we see as our plot, so this is the tsar can plot of upper some.
Ashraf Uddin: And like I said we don't have different plots in shillong areas, yet, so we can see your scene through pleistocene and.
Ashraf Uddin: Your sin has some older material, but this this this House in has almost going up to about our what protocols week affiliate programs like time and then this all you're seeing kind of the similar way, but has a good bit of distribution.
Ashraf Uddin: And then, when you go to the middle of a scene in assamese close to the email and sin taxes we find a different kind of distribution.
Ashraf Uddin: So, and then go up to the scene and and applies to scene, so we see, there is a common assemblage would try to try to connect all these that may be the areas inside somewhat in I would say propitious contributed patricia's deposits contributed significantly.
Ashraf Uddin: In all of our song so where's this coming from so they play applies to see, in a sense, stones are some contents are pounds from.
Ashraf Uddin: It he is he, like he just said here, and again, these are battling over in the Indus some procedure belt So you see in the Tibetan plateau was a yes.
Ashraf Uddin: So now we go into that can plot of the barrel racing again first observation from your seen throughout the scene and even miocene then got samples that old much more older then.
Ashraf Uddin: Then some samples so that makes.
Ashraf Uddin: Good information in there that were could potentially be the sources from so it kind of match with what we found in the in our compositional data that the Indian she might be the source for the bengals sentiments, so we have identified some common areas, what we see.
Ashraf Uddin: Most of the struggle here you presented, not all of them, but most, and these are interesting.
Ashraf Uddin: yeah that one at around 500 millionaires and we're finding many of these in.
Ashraf Uddin: On one assembles close to that a year just so probably if we keep on doing it for further down, we might get the ages of.
Ashraf Uddin: Moscow it just for gone one a sample scar Winifred has gone on and samples will be connected right here as well, so what we have so upper myosin right here.
Ashraf Uddin: sandstone from the bengals provides Arkansas Kimberly and to l'oreal seen as possible derivation of these stocks, mostly from the higher Himalayas they have police a kinetic rocks.
Ashraf Uddin: And this kind of suggest what we infarct based on in the myosin in sections, we find lot of SEM salesforce so it matches the delegation from this forensic igneous rock.
Ashraf Uddin: Now we look at are going are going work on the upper awesome so we have three samples to from a legal scene and one from miocene.
Ashraf Uddin: And so all you're seeing the bottom all allison is here the middle all your Center up all your scene and then this is the Madison one, so we have distribution and there is at least one area we see good bit of presents from all three strategic fees and and.
Ashraf Uddin: What we say that this muscovite cooling ages range from late triassic to he was seeing with dominance of late cretaceous so again we we find.
Ashraf Uddin: These atheists.
Ashraf Uddin: Why what substantially and also in other areas of a song.
Ashraf Uddin: So Martha miles in Moscow ages range from only you seem too late cretaceous again petitions is a dominant contributor edition mosque was in in.
Ashraf Uddin: 2018 as well as nearly instance of a song.
Ashraf Uddin: Now we go back to or zach on plot, one more time so just the LCD between Salman bin all so that comes from using dyson sandstone mostly early productivity, like I showed you here and petitions so it's interesting that the rotting fed reverse train multiple terrains.
Ashraf Uddin: Prior to coming to the city and see that's why many of these sense stones are the meanings instance, are deposited at the time.
Ashraf Uddin: period in that concert absent from this religion sandstorms so many of these tertiary early tertiary magnetism did not contribute.
Ashraf Uddin: To these sense stones to this definition system and that comes from a lucien sandstone the longest in the world, mostly protocol is a cage and may probably source from the Indian shield.
Ashraf Uddin: About desert island blocks, as I can prosper all you're seen as someone well dominant modes of misery and send us a case in Assam.
Ashraf Uddin: And all polycom legacy nearly so much all that so i'd like to reinforce the statement here, that being old sentiments are much older.
Ashraf Uddin: Now we go into this area the middle area around the shillong so we have to our legacy in.
Ashraf Uddin: samples Muscovites or extracted and.
Ashraf Uddin: These are Paleo porter is like PLC installing a scene and con speakers prison so you've seen lead cretaceous they can be an early ordovician ages So these are the.
Ashraf Uddin: Important months that we see so again let pretentious contribution is consistent for all through stratigraphy in in about a song and loss.
Ashraf Uddin: So when you go into miles in Moscow what cooling age.
Ashraf Uddin: In in Upper a son in law, some in these areas, so we'd say miocene too early cambrian so it's interesting.
Ashraf Uddin: And we just just to brief what we have discussed in our song that this is a dominant peak right the dominant.
Ashraf Uddin: Area of like a distribution dominate.
Ashraf Uddin: Early cretaceous lake dishes and this is something that we published some years ago.
Ashraf Uddin: So this is just a miocene Moscow is in the ventilation and we see distribution of plots.
Ashraf Uddin: 11 through 18 and 22 through 26 million years dominant Lee of through so we picked out samples from three different areas, all our Green core samples this time and pointed out very well easily that.
Ashraf Uddin: That that the miles in samples are not very old they are.
Ashraf Uddin: like an older miles in that came in unruly through the Himalayan up lift very quickly, so the wrapping up lift was a suggestion for deposition of this this Moscow heights.
Ashraf Uddin: All right, well with death note, where are the sources for these so we try to draw a map and corresponding ages crystal in ages.
Ashraf Uddin: ages of Christian in Iraq so it's it's many places, and I challenged my students that okay could Eastern hearts, be a source far far away good terroir be a source.
Ashraf Uddin: let's see we haven't gotten any conclusions, but most possible sources are close by.
Ashraf Uddin: that the mission hills in Upper Assam are not Eastern India and again dizzy battling I think that's probably is the dominant contributed have limitations age.
Ashraf Uddin: And she long, although is sitting next to the area, but it did not contribute because we did not find any age on the shillong shillong uplifted much later, it was a flat land at some point.
Ashraf Uddin: of open ocean so thing boom could be so certain awkward plateau could be a source and so now knowing all these time composition time to geochemistry or rob electron probe and then.
Ashraf Uddin: Now to chronology, these are the models that we initially had initially had just the composition, what happened and.
Ashraf Uddin: What happened in this part of the Himalayas mls we suggested that the p mile seen sediment did not come there did not contribute directly from the Himalayas it came from the Indian shield.
Ashraf Uddin: And in the flyer miles seen everything got together and he mother counter clockwise rotation was 33.5 degrees and then here, there was a the player plasticine it's almost like what we see today, so this was our pillar geographically construction long time ago.
Ashraf Uddin: Without the chronology the title the chronology now we have to chronology so we have little defined okay let's move forward with what we see today.
Ashraf Uddin: This is, this is what we have the clear geography, let me go back one more time here are when we did this war just on our sample area was just the yellow we had no idea, but a song.
Ashraf Uddin: And, but when he visited a song, we see that whatever we see a song the crop types, the little types and composition wise matches that off.
Ashraf Uddin: Western Himalayas so in a way, maybe the boats in taxes were made or form during the same time, but the involved did not feel that where.
Ashraf Uddin: did not have the record, so we kind of had this open area either really in or some kind of a barrier, now we know a song.
Ashraf Uddin: That Okay, there was activity, there are authentic events there the origin is events in the western email So how do we reconcile this middle area, so we came up with that the Bengali idea is right here was far down.
Ashraf Uddin: India was moving up.
Ashraf Uddin: From guana from Antarctica and then this fall this light colored and fall brought in close to where it is today, but not until the miles in time.
Ashraf Uddin: So that is a model we are focusing on these days and actually you know, we had a recent graduate student did some technology, which I did not show here also suggesting that way one other student did some organic photography.
Ashraf Uddin: Lip tonight's in that unites and also suggest in many different it's a very low topography of source material plans in that area in many different ways, this is that three miles in deposits in the bin always in were from the West, from an Indian shield.
Todd LaMaskin (he/him): i'm sorry to interrupt but I need to go ahead and ask you to just conclude as quickly as.
Ashraf Uddin: We can, as quickly as you can.
Ashraf Uddin: Okay, so bring all the sins that cancer old.
Ashraf Uddin: And she long plateau received the material shillong plateau in the bargain and all contributed significantly in 123 areas absence of late August in Moscow wide for malinga seen sediments in shillong suggests shillong was not the source.
Ashraf Uddin: The scene and older the title edge mode for mass provide that are characteristics of the legacy I replaced by miles in that's very interesting like there, so the next.
Ashraf Uddin: thing to do is the area between she long and the Bangalore week is not explored very confusing for different students would be working on, thank you very much.
Todd LaMaskin (he/him): Great Thank you so much.
Todd LaMaskin (he/him): So that brings us to our discussion period and I just want to say my own personal thanks to everybody who contributed to our program today some great talks I appreciate hearing from everybody.
Todd LaMaskin (he/him): And if anybody has any discussion items or questions are Dave if you want to make any concluding comments.
I know.
Dave Blake: You guys did a great job everybody I enjoyed it and learn quite a bit great.
Todd LaMaskin (he/him): So, if anyone has any questions for a sheriff or anyone else any other of our speakers or general discussion items feel free to unmute and.
Todd LaMaskin (he/him): just go ahead and speak up.
Dave Blake: And if you would on on on on share your screen.
Okay, thanks.
Dave Blake: Go.
Ashraf Uddin: Did I do anything wrong.
Todd LaMaskin (he/him): No it's just it was a little dog but that's.
Dave Blake: Good.
Todd LaMaskin (he/him): No worries.
Dave Blake: Anybody with questions.
Todd LaMaskin (he/him): Okay, well, we appreciate everyone's attendance, it was a good long day all morning was great all afternoon was great.
Dave Blake: Hopefully you guys learned a few things from Austin last from you and we appreciate your attendance.
Dave Blake: And it's good to see some old faces and some old names.
Todd LaMaskin (he/him): And lots and lots of new faces.
Dave Blake: I think.
Dave Blake: Go ahead Steve.
Steve Godfrey: I was just saying, thanks to everyone, you guys have put it together all the presenters just a great session, thank you.
Dave Blake: bill did a lot of the work, so we appreciate his efforts.
Dave Blake: And thank you, Dr Thomas to for starting us out this morning.
Thomas: Well, thank you, I think it's been a great day.