A Neotectonic based Geomorphic Analysis using Remote Sensing Data to Delineate Potential Areas of Hydrocarbon Exploration: Cachar Area, Assam

Abstract

The Assam Arakan fold thrust belt has highly deformed folded units of Tertiary sediments bounded by eastward dipping thrust slices with a convexity towards west. In the Tripura-Cachar region, this folded belt is characterized by the occurrence of wide synclines and narrow anticlines that hosts a number of hydrocarbon producing fields. In the Cachar area of Assam, most of these fields occur in the culmination of anticlinal structures. Other wells drilled in analogous structural settings are found to be dry. In this paper a neotectonic based geomorphic analysis is carried out to delineate a fault network and geomorphic highs in Cachar area as expressions of sub-surface structures which had subsequently been validated by available geophysical data. Of these geomorphic highs, those that are in the synclinal areas are believed to represent subtle sub-surface structural highs. Synclinal structures associated with NNE-SSW faults might be considered interesting for hydrocarbon exploration and are subsequently categorized following their degree of confidence for exploration of hydrocarbon. Additionally, a genetic model of the structures in the region is also proposed.

Delineation of Subtle and Obscure Structures in West Bengal Shelf:A Remote Sensing and GIS-Based Parallel Approach

“…However, these structures are associated with a predominantly vertical component of deformation 14 that is imprinted on the surface in the geomorphic elements, especially in sensitive elements like drainage, lineaments and topography 14 . The analysis of these elements is based on the principles discussed in the literaure 15,16 and helps to bring out surface manifestations of the subsurface structures. These surface manifestations are then correlated with the available subsurface data to validate them and establish the subsurface continuity of these interpreted structures.…”

“…Geomorphic highs are delineated from anomalous localized drainage geometries like radial drainages (Figure 4 a) and peripheral/curved drainages (Figure 4 b) 15,16 . These features are used for initial delineation of geomorphic highs in the study area identified from the drainage map of the area.…”

Lithofacies, architectural elements and tectonic provenance of Mio-Pliocene Dupitila Formation in the Cachar Thrust Fold Belt, Northeast India

“…This lineament is also observed to join the Dauki fault northeastward, whereas southwestward it passes over the Barisal-Chandpur subsurface gravity high which is considered to be the manifestation of the continent-ocean crust boundary [1]. The intensity of folding in the region increases from west to east [39] affecting the sequence of rocks ranging in age from upper Cretaceous through Cenozoic.…”

“…The belt comprises of thick pile (10-11 km) of sedimentary deposit manifested into a series of NNE-SSW trending, sub-parallel, doubly plunging and highly faulted anticlines and synclines. Major rivers like Barak together with lower-order drainages define a trellis pattern under the influence of alternating synclines and anticlines [39]. The CTFB is bounded on the north by the E-W trending Dauki fault which is assumed to be a thrust associated with right lateral displacement [5,30,34].…”

Detection of hydrocarbon microseepage-induced anomalies by spectral enhancements of Landsat 7 ETM+ images in part of Assam–Arakan Fold Belt, India

“…The basin is characterized by thick clastic sediments consisting of sandstone and mudstone facies ranging in age from Paleocene to Recent. Several oil and gas fields have been discovered in the basin, which are still under production (Chatterjee et al 2006;Mazumder et al 2016).…”