Records of the Geological Survey of India, Volume 103

airborne alluvium anomalies anomaly zones application associated base 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 extent fault field formations frequency G. S. I. report geological geophysical surveys Gondwana graphite gravity ground groundwater highly horizons important in-phase indicated interpretation layers lignite limestone limited locating logging magnetic mapping material measure metals method mineralisation minerals mining nature observed obtained occur ohm-m parties led period places polarisation possible potential presented problem profiles prominent prospecting quartzites radioactivity range recorded refraction river saline schists sediments seismic seismic refraction self-potential shales significant sounding strike structural studies subsurface sulphide surface Survey of India techniques thickness thrust tion traps values various West zones