Uplift along the western margin of the Deccan Basalt Province: Is there any geomorphometric evidence?

Abstract

In line with the passive margin landscape evolutionary model in vogue, sustained erosion and long-distance retreat of the Western Ghat escarpment are widely considered to be the results of erosionally-driven isostatic uplift since Tertiary by many workers. Others have postulated or adduced evidence for strong neotectonic activity in the Ghat region. An obvious question in this regard is whether there is any geomorphometric evidence in support of this widespread view? In order to test the hypothesis of ongoing post-rift fexural uplift or neotectonic activity in the western Deccan Basalt Province (DBP), geomorphometric analysis was carried out and commonly used geomorphic indices of active tectonics (GAT) were derived for 30 selected river basins on both sides of the Western Ghat. SRTM-DEM data and ArcGIS were used to derive the indices. Tectonic geomorphic analysis based on five proxy indicators suggests that the differences in GAT indices, both along strike and across the Western Ghat, are statistically insignificant. The index values are nowhere close to the GAT values typically associated with drainage basins affected by active tectonics and deformation. Mapping of the indices reveals lack of discernable trends. The adduced results indicate that the western DBP belongs to the class of relatively low tectonic activity.

Tectonic Control on Drainage Network Evolution in the Upper Narmada Valley: Implication to Neotectonics

“…Calculation of the number of geomorphometric indices for a large region such as central peninsular India was made possible by the analysis of ASTER 1.5 arc second satellite data. The ASTER data have been found to be suitable for regional scale morphometric analysis [39,40]. The Narmada river originates from Amarkantak at a height of 1068 m.a.s.l.…”

“…For geomorphometry, four commonly used geomorphic indices of active tectonics such as stream length gradient index (SL), asymmetry factor (AF), transverse-topographic symmetry ( ), and valley floor height Ratio (Vf) have been used which are calculated for the different segments. These indices are considered powerful tools to evaluate the relationship between tectonics and basin morphology on the regional or basin scale and to identify geologically recent deformation [36,40].…”

“…The downcutting of valley is commonly associated with the higher rate of uplift in tectonically active areas. The small values of Vf (<1) reflect deep narrow, V shaped valleys which are commonly associated with relative rapid uplift [40]. In contrast, high values (>1) are markers of wide open valleys in the regions of minimal uplift rates [37].…”

Landscape response to recent tectonic deformation in the SW Pannonian Basin: Evidence from DEM-based morphometric analysis of the Bilogora Mt. area, NE Croatia

“…The Asymmetry Factor (AF) has been used to quantify drainage basin geometries and can indicate possible tilting of the basin (Hare and Gardner, 1985;Keller and Pinter, 2002;Molin et al, 2004;Kale andShejwalkar, 2008, El Hamdouni et al, 2008;Dehbozorgi et al, 2010;Pérez-Peña et al, 2010;Matoš et al, 2014).…”

Active tectonics of NE Gujarat (India) by morphometric and morphostructural studies of Vatrak River basin

“…1 (continued) et Raj, 2004Raj, , 2007Kale and Shejwalkar, 2008;Larue, 2008;Guarnieri and Pirrotta, 2008). Also geomorphometric characterisation of landform was attempted by calculating some commonly used geomorphic indices of active tectonics.…”