Nature of the Moho in the mid-eastern part of the Chotanagpur Plateau, India, from a receiver function perspective

The present study aims to find out the crustal thickness, V (P)/V (S) ratio, and Poisson's ratio beneath the Indian School of Mines (ISM) broadband seismic station using receiver function analysis. The station is located at latitude 23.82A degrees N and longitude 86.44A degrees E in the mid-eastern part of the Chotanagpur Plateau under the Eastern Indian Shield region. A total of 300 teleseismic events (M a parts per thousand yenaEuro parts per thousand 6.0), recorded at the ISM station during 2007-2012, were compiled, and 97 good-quality events selected for the analysis. Receiver function analysis and H-k stacking method are used to determine the crustal thickness (H) and V (P)/V (S) ratio. The depth of MohoroviiA double dagger (Moho) discontinuity below the station is estimated to be similar to 42.2 km with an average V (P)/V (S) ratio of similar to 1.92. We also find the presence of Conrad discontinuity at a depth of similar to 20 km. The computed average Poisson's ratio of similar to 0.31 for the whole crust beneath the ISM broadband station is relatively higher and might be indicating the presence of mafic rocks or partial melt near the Moho. Similar observations were also reported from different segments of the Son-Narmada-Tapi mega-shear zone, a westward extended part of the present study area.