HR: 14:55h
AN: GP43C-06    [Abstracts]
TI: Comparison of Stratigraphic and Structural Evolution of Verkhoyansk and Cordillera Miogeoclines
AU: * Sears, J W
EM: jwsears@selway.umt.edu
AF: Department of Geology, University of Montana, Missoula, MT 59812 United States
AU: Khudoley, A K
EM: khudoley@ah3549.spb.edu
AF: Geological Department, St Petersburg State University, St Petersburg, 199034 Russian Federation
AU: Prokopiev, A V
EM: prokopiev@diamond.ysn.ru
AF: Diamond and Precious Metal Geology Inst, 39 Lenin Ave, Yakutsk, 677891 Russian Federation
AB: Many Precambrian plate restorations place one of the rifted margins of the Siberian craton against one of the rifted margins of Laurentia. Inherent in the proposed restorations is the implication that the conjugate margins share a similar geodynamic history of rifting and thermal subsidence until interrupted by other tectonic processes. We compare the stratigraphic and structural history of Verkhoyansk miogeocline of the rifted southeastern margin of the Siberian craton with that of the Cordilleran miogeocline of the rifted southwestern margin of the North American craton to test predictions of the Precambrian plate restoration of Sears and Price (2003). We report on the results of joint expeditions down the Belaya River of Siberia and to the Death Valley and White-Inyo region of southeastern California. We find many points of lithostratigraphic and structural similarity between correlative platformal and miogeoclinal units ranging in age from Mesoproterozoic to Carboniferous. Collections of clastic rocks from both regions are being processed for detrital zircon analysis to verify putative lithostratigraphic matches. Our preliminary observations are consistent with the proposaal of Sears and Price (2003) that the margins rifted apart during latest Precambrian and thermally subsided as passive conjugate margins during early Paleozoic. Both margins experienced significant tectonic interruptions during late Devonian to Carboniferous time.
DE: 8100 TECTONOPHYSICS
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting