首页 | 本学科首页   官方微博 | 高级检索  
     检索      


The Triassic of the Thakkhola (Nepal). II: Paleolatitudes and comparison with other Eastern Tethyan Margins of Gondwana
Authors:J G Ogg  U von Rad
Institution:(1) Department of Earth and Atmospheric Sciences, Purdue University, 47907 West Lafayette, Indiana, USA;(2) Bundesanstalt für Geowissenschaften und Rohstoffe, PF 51 01 53, D-30621 Hannover, Germany
Abstract:During the Triassic, the Thakkhola region of the Nepal Himalaya was part of the broad continental shelf of Gondwana facing a wide Eastern Tethys ocean. This margin was continuous from Arabia to Northwest Australia and spanned tropical and temperate latitudes.A compilation of Permian, Triassic and early Jurassic paleomagnetic data from the reconstructed Gondwana blocks indicates that the margin was progressively shifting northward into more tropical latitudes. The Thakkhola region was approximately 55° S during Late Permian, 40° S during Early Triassic, 30° S during Middle Triassic and 25° S during Late Triassic. This paleolatitude change produced a general increase in the relative importance of carbonate deposition through the Triassic on the Himalaya and Australian margins. Regional tectonics were important in governing local subsidence rates and influx of terrigenous clastics to these Gondwana margins; but eustatic sea-level changes provide a regional and global correlation of major marine transgressions, prograding margin deposits and shallowing-upward successions. A general mega-cycle characterizes the Triassic beginning with a major transgression at the base of the Triassic, followed by a general shallowing-upward of facies during Middle and Late Triassic, and climaxing with a regression in the latest Triassic.
Keywords:Triassic  Gondwana  Himalaya  Sediment history  Paleomagnetism  Apparent polar wander
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号