HR: 0800h
AN: GP41A-0832    [Abstracts]
TI: Russian East Arctic Shelf: Structural Outline
AU: * Kosko, M
EM: kosko@vniio.nw/ru
AF: VNIIOkangeologia, 1, Angliisky Ave., St. Petersburg, 190121 Russian Federation
AB: The Laptev Sea Basin is open towards the Eurasia Basin. A set of grabens have been discovered within the basin. The sedimentary cover thickness exceeds 10 km. The initial Precambrian basement was rejuvenated in the MZ. The sedimentary cover is dividable into late Precambrian to early Cretaceous and early Cretaceous to CZ structural stages. The Sviatoi Nos-Kotel'ny High and The De Long High mark the boundary between the Eurasia and Amerasia continental margins separating the Laptev Sea Basin from the basins underlying the East Siberian Sea (ESS) and the Chukchi Sea (CHS) shelf. Late Kimmerian basement and PZ and MZ moderately deformed strata were mapped within the Sviatoi Nos-Kotel'ny High. The De Long High is located on the NW ESS. The Caledonian tectonic basement is exposed on the New Siberian islands. PZ and MZ strata of the intermediate structural stage may be present offshore. The upper structural stage of the sedimentary consists of Cretaceous to CZ volcanics and siliciclastics. The ESS and CHS shelf is a huge basin filled with Pliocene and Quaternary sediments deposited on a complex structural ensemble. The Novaya Sibir' Megabasin is comprised of a series of structures. The most prominent one is the New Siberian Rift Basin with sediments up to 12 km thick. The New Siberian Basin parallels the different aged basement blocks which mark the boundary of the late Kimmerian deformation front. The Vil'kitsky Rift Basin is located on the NE ESS and N CHS. It projects as a continental slope basin to the NW and crosses the US/Russian boundary to the East. The depth of the basin exceeds 17 km. And contains an early Cretaceous molasse at the base of the sedimentary fill. Late Cretaceous sedimentation was fault controlled. Tertiary strata form a platform type syncline. The lowermost reflections on the south slope of the Basin are related to the intermediate structural stage. The Wrangel-Herald Ridge separates the Vil'kitsky Basin from the South Chukchi Basin. The late Kimmerian tectonic basement capping the ridge is exposed on Wrangel island. The South Chukchi Basin extends from the SE ESS to the SE CHS. The basin fill is late MZ to CZ strata up to 8 km thick, overlying the late Kimmerian basement. The basal portion of the sedimentary fill is believed to be the early Cretaceous molasse.
DE: 9315 Arctic region
DE: 9320 Asia
DE: 8155 Plate motions--general
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting