Regional Surface Electrical Conductance Map of India

Electrical conductance is one of the important parameters in the interpretation of electrical and electromagnetic data. Study of the distribution of conductance parameter in a region helps to understand the subsurface geoelectric structure. Based on the results obtained from shallow electrical resistivity soundings, deep resistivity and magnetotelluric (Mn soundings, geological sections derived from a few deep seismic soundings (DSS) and from shallow and deep boreholes, an attempt has been made here to construct a regional electrical conductance map of India. Since the data is widely distributed more emphasis is given for the data from sedimentary basins. The map thus prepared gives the distribution of conductance values of various geological regions. The regions in Arunachal Pradesh, Assam in northeast, Ganga valley in the north and Cambay in western part show comparatively high conductance values, of the order of 400-1500 Siemens.