Three-dimensional gravity modelling of Kutch region, India

摘要

Understanding the crustal architecture of Kutch rift region, India is important due to the presence of thick Mesozoic sediments and also due to occurrence of earthquakes. We present here three-dimensional gravity models. The major features of our shallow crustal model are: (1) thickness of Deccan Traps is almost negligible towards northern side of Vigodi Fault and Katrol Hill Fault (2) Mesozoic sediment thickness is about 3 km on the southern side and (3) several undulations in the basement on the Wagad Uplift. The model is consistent with the geological observation that the basin slopes towards southwest. The observed Bouguer gravity anomalies are explained by similar to 10 km thick Granitic upper crust of 2.7 g/cm(3); similar to 10 km thick intermediate mid crust of 2.82 g/cm(3); similar to 15 km thick mafic lower crust of 2.91 g/cm3 density. Crustal thickness is about 40-45 km on Wagad Uplift and near Katrol Hill Fault. The modelled gravity data do not require presence of anomalous amount of fluids, melts and/or magma chambers in the deep crust of Kutch region. (c) 2015 Elsevier Ltd. All rights reserved.