Equipment for carrying out quantitative geoelectromagnetic model experiments

Summary The paper describes equipment designed to study the effect of a conducting hostrock/overburden on the electromagnetic anomaly of sulphide ore bodies embedded therein. The model was constructed strictly according to the theory of electromagnetic similitude so as to constitute a direct reading reproduction of the field vectors. The experiments were conducted at a fixed, crystal-controlled frequency of 100 kHz using mainly a graphite sheet immersed in a dilute hydrochloric acid solution of predetermined conductivity to simulate vein and manto type of ore deposits surrounded by a partially conducting zone. Both the inphase and quadrature components of the anomaly were measured in terms of the primary field after elimination of the regional anomaly by means of a measuring bridge and a compensator. A comparison of the anomaly profiles obtained over the ore model when it is held in air with those obtained for corresponding situations inside a conducting solution shows a general enhancement of response 1–3].