CHIM method

In the CHIM method of prospecting a direct current is introduced into the ground by means of a current electrode and an element collection electrode. This facilitates the extraction and accumulation of ions of the metals in zones near electrodes. The subsequent analysis of the extracted metals yields information about their distribution in the rocks in the zone of investigation. 

Equation (2.19) lays down the theoretical basis of the element-collector function for the CHIM methods (and for the MDE method, described below). 

For the high values of current and current density in the CHIM method we can suppose. 

Different types of equipment have been designed in Russia for the CHIM method. The CHIM-k installation has a capacity of 10 Kw and allows the use of 40 element-collectors with a current and voltage stabiliser. Another installation consists of two modules and allows the use of 60-120 element-collectors simultaneously. 

Fig. 2-22 Results obtained by the CHIM method over polymetallic mineralisation in Rudny Altay, Russia PbniiM- concentration of mobile forms of lead (CHIM) Pb,otar total concentration of lead (lithogeochemistry) 1- unconsolidated sandy-clay overburden 2- volcaniclastic strata 3- polymetallic ore 4- low-grade disseminated ore (reproduced with permission from Ryss,1983).

Fig. 2-23. Results obtained by the CHIM method over tin stockwork ore in Primorsky Kray, Russia results of lithogeochemieal survey (A) at surfaee, (B) in rocks in trenches, and (C) results of CHIM survey 1- Quaternary sediments 2- aleurolitcs and sandstones 3- tin stockwork ore 4-small veins of tin mineralisation 5- small veins of polymetallic mineralisation (reproduced with permission from Alekseev et al., 1981).

Fig. 2-24. Results obtained by the CHIM method over beryllium mineralisation in Byelorussia (A) plan of beryllium anomaly, and (B) distribution of beryllium along profile and schematie geological section 1- sands, clays 2- diabases 3- granites 4- tectonic disjunctions 5- ore bodies 6- zones of mineralisation (reproduced with permission from Bensman et al., 1982).

The role of CHIM in oil prospecting is illustrated in Fig. 2-26. The perimeter of the oil deposit at depth of about 2500 m is satisfactorily delineated by the contour of maximum lead mass extracted by the CHIM method. 

Fig 2-25 Results obtained by the CHIM method at the Prijutinsky section (A) concentration of gold in placer, (B) results of extraction of gold by means of CHIM 1- clays 2- gravels 3-phyllites 4- crystal slates 5- placer (reproduced with permission from Karar and Sakovich, 1989). 

Fig. 2-26. Results obtained by the CHIM method over an oil deposit in Byelorussia and schematic geological section 1- Permian-Cretaceous-Quatemary clays, sands, coals 2- marly siliceous clay formations 3- Carboniferous sand-clay formations 4- middle-late Devonian sandstones, aleurolites, marls 5- oil deposit (reproduced with permission from Ryss et al., 1990).

Karar, V.P.and Sakovich, B.B., 1989. Application of the CHIM method for prospecting placer gold deposits at the Enisey mountain-ridge. Application of Geoelectrochemical methods for Prospecting and Exploration of Ore Deposits. NPO Rudgeofizika, Leningrad, pp. 189-112 (in Russian). 

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