Applicability of the sequence framework in IEAP and GTM, with brief comments on the hydrocarbon prospects in the Indian basins

Abstract

The validity of the Indian first- and second-order sequence stratigraphic framework is first demonstrated in India and IEAP through the isochronous character of as many sequence surfaces as possible. It is realized through investigation of the formulated sequence surfaces in the relatively better studied time slices in specific basins of the different sectors (Fig. 5.1). Subsequently, detailed comparison of the developed Indian succession of sequence surfaces is made, particularly, with the Arabian Triassic–Jurassic, and Madagascar Jurassic–Cretaceous (Figs. 5.1, 5.2, 5.3, 5.4, 5.5 and 5.6), as also mutually among the Jurassic development in India, Madagascar and Arabia (Fig. 5.4). Comparison of the Indian sequence framework is also made with regions/basins east of India at the first-order level with Dampier (Fig. 5.7), West Irian (Fig. 5.8), Timor/Sula (Fig. 5.9), and Timor Gap (Fig. 5.10), as also at second-order level with Dampier and West Irian basins. The comparisons exhibit substantive concordance of the large number of first- and second-order surfaces on the GTM both east and west of India. Comparison is also made of the Indian framework with the ETM framework, and salient differences are brought out. The comprehensive exercise reaffirms the earlier held view of the author of the need of independent development of the Indian framework. In comparison with ETM, almost all the Indian first-order surfaces (SBs/MFSs) invariably disagree in ages with the corresponding ETM surfaces by several ammonoid zones, and the obvious influence of regional tectonics in GTM is brought home well. The discordance is excellently exampled by the GTM intra-Jurassic first-order MFS in late Middle Oxfordian Orientalis Zone Schilli Subzone and the corresponding ETM first-order MFS in late Late Kimmeridgian Beckeri Zone. In contrast to the corresponding diachronous first- and second-order surfaces, the third order and finer high frequency low magnitude sequences are considered punctuated by synchronous sequence surfaces across the globe, since being governed by the earth’s orbital dynamics which could not be distorted by low-frequency and high-magnitude first- and second-order extensional tectonics. The chapter is concluded with summarized sequence stratigraphy-based evaluation of the hydrocarbon prospects in the mega-sequence geological record of the Indian basins that reflect an over all positive outlook. An elaborate Indian hydrocarbon prospect analysis being outside the scope of the present work is planned separately in near future. © Springer Science+Business Media Singapore 2017.