Northeastern Section (45th Annual) and Southeastern Section (59th Annual) Joint Meeting (13-16 March 2010)
Paper No. 17-1
Presentation Time: 1:35 PM-1:55 PM


BARTHOLOMEW, Mervin J., Earth Sciences, Univ of Memphis, Memphis, TN 38152, and HATCHER, Robert D. Jr, Earth and Planetary Sciences and Science Alliance Center of Excellence, University of Tennessee-Knoxville, 306 EPS Building, Knoxville, TN 37996-1410

Palinspastic maps of terranes of the Grenville orogen are portrayed on the magnetic anomaly map of North America for the Elzevirian orogeny; the Shawinigan, Ottawan, and Rigolet phases of the Grenvillian orogeny; and post-Grenvillian magmatism during failed rifting (760-600 Ma) prior to successful Iapetan rifting at 565 Ma. Accreted terranes had unique histories prior to amalgamation and share common tectonic events afterwards. The Elzevirian suture, partially preserved beneath the Appalachians, separates the Reading Prong terrane from Laurentia (i.e., Adirondacks and composite-arc terrane and Canadian Grenville province). The Shawinigan suture, partially preserved in the Llano area, separated the now-fragmented and allochthonous Amazonian blocks of the outboard Blue Ridge and Sauratown Mountains terranes from the Reading Prong terrane in the Appalachian region. Within Laurentia, the Mars Hill terrane, containing a pre-Grenvillian inlier, is the only fragment of Amazonia believed to have been accreted during the main Ottawan phase. The outboard Ottawan suture may have served as locus of Iapetan rifting along much of Laurentia. The Rigolet phase (ca. 1020-1000 Ma) is characterized by widespread “Basin and Range” type extension (NW-SE) associated with inferred sinistral movement on the NY-AL lineament, mobilization of core-complexes (Adirondack Highlands), and AMCG magmatism along the outboard flank of the extensional region. Subsequently, the Appalachian region is characterized by NW-SE extension during passage of a possible hotspot along a NE-track (760-600 Ma) across the Blue Ridge and other terranes, prior to successful Iapetan rifting (565 Ma). The palinspastic rifted margin of southern Laurentia crosses many of these terranes and sutures as well as the possible region of Rigolet extension and the possible hotspot track, thus providing many potential piercing points within the Grenville orogen for comparison with terranes of Amazonia or elsewhere.

Northeastern Section (45th Annual) and Southeastern Section (59th Annual) Joint Meeting (13-16 March 2010)
General Information for this Meeting
Presentation Handout (.ppt format, 19361.0 kb)
Session No. 17
The Iapetan Rifted Margin and Rift History of Eastern Laurentia II
Sheraton Baltimore City Center: Liberty B
1:30 PM-3:15 PM, Sunday, 14 March 2010

Geological Society of America Abstracts with Programs, Vol. 42, No. 1, p. 78

© Copyright 2010 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.