The Principles & Practice of Geophysical Prospecting

A.C. potential ratio alluvium alternating current apparatus Australia axis basalt Beacon beam bed-rock Bore bore-hole C₁ cable calculated carried Chillagoe clay coal coil conductive bodies conductive zones conductor copper country rock curve depth determined direction distance district dyke effect electrical methods electrodes electromagnetic ellipse equipotential line method equipotential line survey equipotential surfaces explosion formations frequency gabbro Gelliondale geological Gish and Rooney gossan gradients gradiometer graphite gravimetric gravity Gulgong H₁ horizontal component indication induction instrument investigations located lode loop magnetic anomalies magnetic field magnetite magnetometer measured mineral Mines Moonta Murrayville negative centres observed occur ohm cm ore-bodies out-of-phase overburden phase angle plane position potential ratio method potentiometer primary field pyrites pyrrhotite recorded Renison Bell resistivity scale secondary field seismic seismometer Shaft shown in Fig slate South spontaneous polarization stations sulphide Tasmania tests torsion balance traverse velocity wave wire