Shallow geological environment of Krishna–Godavari offshore, eastern continental margin of India as inferred from the interpretation of high resolution sparker data.

Abstract

Krishna–Godavari offshore basin, a part of the eastern continental margin of India is a proven petroliferous basin. Recent drilling in this area in search of gas hydrates reveals that the upper 300 m thick Quaternary–Recent strata comprised of nannofossil bearing rich clays and, fractures/faults are the suitable zones for gas hydrates accumulation. Therefore, the knowledge about the shallow geological environments and its architecture are significantly important in assessing the gas hydrates potential of this area. In order to enhance the geological understanding, the newly acquired high resolution seismic (HRS) reflection data in this gas hydrates prone area is interpreted. The processed seismic sections show a maximum penetration of 562 ms TWT (450 m) underneath the seabed with high resolution stratication. An attempt has been made to: (i) deduce the shallow geological environment from the reflection characteristics, and, (ii) assign tentative ages under the constraints of drilling/coring results. We further explained the observed folded structures on the surface and subsurface through a mechanism linked to shale tectonism and neotectonic activity.