Basement tectonics and flexural subsidence along western continental margin of India

Basement tectonics and flexural subsidence along

western continental margin of India

D.K.Pandey;Nisha Nair;Anju Pandey;G.Sriram

【期刊名称】《地学前缘(英文版)》 【年(卷),期】2017(008)005

【摘要】The Paleocene-recent post-rift subsidence history recorded in the Mumbai Offshore Basin off western continental margin of India is examined.Results obtained through 2-D flexural backstripping modelling of new seismic data reveal considerable thermo-tectonic subsidence over last ca.56 Myr.Reverse postrift subsidence modelling with variable β stretching factor predicts residual topography of ca.2000 m to the west of Shelf Margin Basin and fails to restore late Paleocene horizon and the underlying igneous basement to the sea level.This potentially implies that:(1) either the igneous basement formed during the late Cretaceous was emplaced under open marine environs;or (2) a laterally varying cumulative subsidence occurred within Mumbai Offshore Basin (MOB) during ca.68 to ca.56 Ma.Pre-depositional topographic variations at ca,56 Ma across the basin could be attributed to the extensional processes such as varied lower crustal underplating along Western Continental Margin of India (WCMI).Investigations about basement tectonics after unroofing of sediments since late Paleocene from this region support a transitional and heavily stretched nature of