|Northeastern Section - 44th Annual Meeting (22–24 March 2009)|
|Paper No. 26-4|
|Presentation Time: 11:40 AM-12:00 PM|
THE CASE FOR A MASSIVE AUSTRALIAN PRECAMBRIAN CAMBRIAN IMPACT STRUCTURE(MAPCIS)
CONNELLY, Daniel P., 4815 Covered Bridge Rd, Millville, NJ 08332, firstname.lastname@example.org|
Background: A 2000km diameter ring was found in Australia using Google Earth. Investigation into the nature of this ring commenced to ascertain its structure and origin. Methods: Maps and mapping techniques were use to verify the structure of the ring. Elevation traverses were made of the dimensions of the ring using Google Earth and graphing the results. Intersection of bisects was used to find the center. A Geoscience Australia Magnetic Anomaly Map and a Gravitational Anomaly Map were overlaid to the Google Earth Map. 1:250,000 GA geo maps and magnetic Intensity maps were used to identify and date specific features. An expedition to the Australian outback was in Jan. 2008 to ground truth the maps. Results: An outer ring was measured ~2000km N. to S. and ~2100km E. to W. centered 40km W of Mt.Connor. The ring has 290 degrees of arc excluding possible undersea portion. The ring width varied from 170km to 250km. Elevation differentials were 50m over the 250km width in the North, to over 200m in the SE. The elevation traverses showed evidence of low wide inner rings and a central rise. The GA MAM and GAM overlays showed the location of the inner rings. The GA MAM and GAM both show a large centered elliptical anomaly ~333km N. to S. and ~700km E. to W. The GA MIM of the Ayers Rock region shows a comet shaped magnetic low, that runs NE to SW between Ayers Rock and Mt. Connor, that suggests an sediment covered excavated region ~50km wide by ~150km long at the geographic center of the outer ring.
The Musgrave Mountains and faults in the SW vector in front of the magnetic low are elongated and form a fan pattern that runs through 200 degrees of arc with a focus at the center of suspected impact. In the S to SE vector 50km to 100km from the impact center is a 150km long and up to 4km wide arcuate band of pseudotachylite with 2 perpendicular non fault bands of PT . GA seismic transects of the impact center suggest that Precambrian sediment layers are missing to the crystalline basement at the suspected impact site. The GA geo
maps indicate the ridges of the inner basin were deformed ~545mya and were ~500km in diameter before being remodeling. The GA geo maps date the PT to ~545mya. The GA geo maps show evidence of ridges that form concentric rings with diameters of ~600km and ~700km. Conclusion: There is evidence for a massive impact in Central Australia that occurred ~545mya.
Northeastern Section - 44th Annual Meeting (22–24 March 2009)
General Information for this Meeting
|Presentation Handout (.ppt format, 24937.0 kb)|
|Session No. 26|
Remote Sensing Applications to Geomorphology
Holiday Inn By the Bay: Rhode Island Room
10:40 AM-12:00 PM, Monday, 23 March 2009
Geological Society of America Abstracts with Programs, Vol. 41, No. 3, p. 38
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