GIS based integration of multi-spectral remote sensing and morphostructural analysis for delineating potential areas of hydrocarbon exploration in Western Vindhyan Basin, India

Abstract

The Chambal Valley forms the western part of the Proterozoic Vindhyan Basin that has been less studied and poorly explored from the hydrocarbon perspective than its eastern counterpart—the Son Valley Vindhyans. In the present manuscript, attempts have been made to use remote sensing and GIS (geographic information system) based analysis to focus on the northern part of Chambal Valley to decipher its tectonics and structural configuration, its tectonic relation with the Son Valley Vindhyans, Bundelkhand Massif and Ganga Basin. This study also assumes significance as it attempts to delineate potential lead areas for hydrocarbon exploration in Chambal Valley. As part of the study, a detailed spectral analysis based on image data sets is carried out to identify areas of microseeps as proxies of potential hydrocarbon accumulations. Also, a neotectonics-based geomorphic analysis is carried out to delineate a fault network and geomorphic highs that act as aliases to subsurface faults and structural highs. The results are subsequently validated by available geophysical data and extensive fieldwork, and suggest four structural trends in the Chambal Valley as striking NE-SW, E-W, NW-SE and N–S, of which the NW-SE trend is the oldest, followed by the NE-SW, E-W and N–S trends. A GIS-based analysis of the E-W trends indicates that these are probably manifestations of the westward continuity of E-W-trending shear zones developed in Bundelkhand massif within the basement of the Chambal Valley. Further remote sensing studies of the shear zone network exposed in the Bundelkhand massif indicate the pattern to be replicated on a larger scale in the morphostructural fault layout in the adjacent Ganga Basin, implying these shear zones may be continuing in the basement of Ganga Basin and controlling structures developed later, and consequently the different petroleum system elements in the basin. A dip data based structural analysis of the Chambal Valley describes a regional synform attributed with an almost vertical NW-SE-trending axial trace. This axial trace may be in continuity with the NE-SW-trending synformal axis of the Son Valley with its trajectory sympathetic to the southern boundary of the Bundelkhand massif and the Central Indian Tectonic Zone (CITZ) – Aravalli Delhi Fold Belt (ADFB) geometry. Finally, based on the integration of the results of spectral and morphostructural analysis, a number of potential areas of hydrocarbon exploration are demarcated in the study area.