HR: 0800h
AN: GP41A-0831    [Abstracts]
TI: Reconstruction of Cretaceous-Cenozoic Tectonic Stress Fields in the Vicinity of Diffuse Plate Boundary Between North American and Eurasian Plates (Laptev Sea Region)
AU: Verzhbitsky, V E
EM: verba@ocean.ru
AF: Shirshov Institute of Oceanology RAS, 36, Nakhimovsky prosp., Moscow, 117997 Russian Federation
AU: * Drachev, S S
EM: drachev@newfields.ru
AF: New Fields Ventures Ltd./Shirshov Institute of Oceanology RAS, 77/1, Sadovnicheskaya Embankment, Entrance 3 , Moscow, 115035 Russian Federation
AB: We present reconstructions of the Cretaceous-Cenozoic tectonic stress fields for the Laptev Sea Region. This study is based on analysis of the mesostructures observed mainly within the Middle-Upper Paleozoic sedimentary rocks along the western part of the New Siberian Archipelago (Bel'kov Island) and the Northern Verkhoyansk Range. The earliest stage of deformation is expressed in the syn-sedimentary (slump) folds identified in the Upper Paleozoic clastic rocks in the both regions. It seems that they mark the earliest stages of the South Anyui oceanic basin development. The main compressional stage took place in the Early Cretaceous over the vast Siberian Arctic continental margin and is known as Late Mesozoic Orogeny. According to our results, studied areas reveal NE-SW and NW-SE compression stresses for Bel'kov Island and Northern Verkhoyansk Region respectively. Then, most likely in the Late Cretaceous, both regions were subjected to E-W compression followed by N-S compressional stage. The latter is well-determined in the Northern Verkhoyansk Range and much less expressed at the Bel'kov Island. During subsequent (latest Late Cretaceous-Cenozoic) rift-related stage the tension stress was oriented E-W to NE-SW, roughly orthogonally to the Laptev Sea rift system; though a secondary NW-SE extension stress is also recognized. The work was supported by INTAS grant 01-0762 (NEMLOR), MK-2487.2003.05, NS-1980.2003.5 and RSSF grants.
DE: 8005 Folds and folding
DE: 8010 Fractures and faults
DE: 8102 Continental contractional orogenic belts
DE: 8105 Continental margins and sedimentary basins
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting