Guido Staltari

Renaissance Capital Pty Ltd

Downhole Electromagnetic Methods

During the past decade, downhole electromagnetics (DHEM) has become a very important exploration method for conductive mineralisation, particularly in areas where the ability of surface EM to define a target is limited either by large depths or by interfering conductive bodies such as overburden, shallow sulphides and peripheral mineralised horizon...

Sign changes at a particular receiver location are commonly observed in downhole TEM data as a function of delay time. There are many causes but generally they can be classified as being due to either a change in the sense of coupling between the downhole probe and the analagous secondary field, or a reversal of the analagous secondary field itself...

Several years after the combined geophysical-geochemical discovery of the Que River gold-silver base-metal deposit in the Mt Read Volcanics of Tasmania, experimental SIROTEM and UTEM surveys were completed with the aim of determining their effectiveness in the search for similar volcanogenic ore types. Of the two main mineralized ore lenses at Que...

The Drake mineral field, which is located in far north-eastern NSW (Fig. 1), encompasses both a number of gold lodes in which near surface oxidized ores were mined during the 1800s and early-mid 1900s, and several more extensive zones of gold?silver mineralization which have been outlined during extensive drilling by joint venture comprising Mt Car...

The Mt Keith South prospect is located approximately 500 km north of Kalgoorlie and 80 km north of Agnew, Western Australia (Fig. 1). The prospect is covered by a joint venture between Cliffs International Inc. and the Charterhall Group. Cliffs International are the present operators. Three currently favoured TEM (Transient Electro-Magnetic) system...

During an exploration programme for volcanogenic massive sulphides in the Mt Windsor belt of north-east Queensland ,a variety of transient electromagnetic (TEM) profiles were measured over a particular prospect. On the basis of separated-loop SIROTEM and fixed-loop EM 37 profiles the most distinctive anomaly was initially interpreted to be due to a...

Results from the Elura DIGHEMII survey indicate that the ore-body was not detected by the towed-bird helicopter-borne system. Although the bulk oxidation zone response was suppressed by data processing, all of the electromagnetic anomalies outlined appear to be caused by discrete changes in the conductivity?thickness product of the oxidation zone,...