Morphotectonics and paleostress analyses of Kutch area, Gujarat, India

Abstract

The Kutch Rift Basin (KRB) is of great attention for its possible hydrocarbon reserve. In this context, geomorphologic and structural geologic studies of the onland basin area are crucial. Application of geomorphic indicators viz., compactness coefficient (Cc), lemniscate coefficient (k), form ratio (Rf), basin shape index (Bs), basin asymmetry factor (AF), hypsometric integral (HI), elongation ratio (Re) and circularity ratio (Rc) have been utilized to calculate the Index of Active Tectonics (IAT) for a part of KRB. Watersheds 5 (the Bhuj area), 9, 10, 11, 17, 18 and 20 belong to class 1 as per the IAT. This indicates that these watersheds are very highly tectonically active at present. Calculated valley floor width height ratio (Vf) and mountain front sinuosity (Smf) quantify the active valley incision in the Quaternary that uplifted the Bhuj area. This uplift was accompanied by a high-degree of drainage rejuvenation due to neotectonics and formation of a canyon in the Khari river. Paleostress analyses revealed NNE and NW-oriented extensions around Bhuj that can correspond to NW and NNE-trending normal fault planes, respectively.

Keywords

• Deformation mechanism
• Plate tectonics
• Geodynamics
• Rift basin
• Basin tectonics