15:00 〜 16:00
[S21-P-04] Lithospheric Density Structure of Northwest India
Northwest India is an amalgamation of diverse geological terranes, evolved during past geological periods. In order to comprehend plausible geodynamic models, which can explain continental evolution in the northwest India deep lithosphere density structure of an area encompassing 200 to 300N latitude and 680 to 780E longitude is derived from the integrated modelling of gravity and geoid anomalies and topography and heat flow data. The derived model is well constrained by available seismic Moho depth. Model shows that the Moho depth varies from 34 to 38 km in Saurashtra and Kachchh region, which increases gradually to about 42 km beneath the Jaisalmer region. The deepest Moho at about 50-53 km is found under the Indo-Gangatic plain. A uniform crustal thickness of 40-43 km is observed beneath the Bundelkhand craton. The depth of lithosphere-asthenosphere boundary (LAB) is 110-125 km under Saurashtra and Kachchh regions which remains same under Barmer basin. A moderate LAB under the Aravalli-Delhi fold belt is observed at a depth of 120-140 km. The LAB depth increases up to 195 km below the Indo-Gangatic plain whereas in Bundelkhand craton the LAB depth ranges from 130 to 155 km.