Records of the Geological Survey of India, Volume 103

airborne alluvium anomalies anomaly zones application associated base basin bed rock belt bodies borehole buried carried causative clay coal components conducted conductor copper covered curves delineated deposits depth determine district drilling effect electrical logging electrical resistivity electromagnetic employed engineering estimated exploration extension fault field formations frequency G. S. I. report geological geophysical surveys Gondwana graphite gravity ground groundwater horizons important India indicated interpretation investigations layers lignite limestone limited locating logging magnetic mapping material maximum measure metals method mineralisation minerals mining nature observed obtained occur ohm-m overburden parties led period places polarisation possible potential presented problem profiles prospecting quartzites radioactivity range recorded refraction river saline sandstones sediments seismic seismic refraction self-potential shales significant sounding strike structural studies subsurface sulphide surface techniques thickness thrust tion traps values various West zones