Studies on selection of rational complex of nuclear geophysical methods of logging in bauxite fields

Unambiguous localization of bauxites in borehole sections from well-logging data is feasible provided the latter help to determine the alumina and silica contents. At present neutron-activation logging with an isotopic source allows only alumina contents to be determined. The existence of a correlation, in the case of bauxites, between the total content of alumina, iron and titanium oxides determined from the neutron-activation and selective gamma-gamma logging data, on the one hand, and that of silica, on the other, enables an estimation of silica content to be made using the above measurements. The accuracy of silicon-module determinations made in this way is 20 to 30 per cent under favourable conditions. Gamma-gamma density logging is introduced into the combination to evaluate the volume weight of the bauxites. The combination proposed has been tested on the bauxite deposits of the Kursk Magnetic Anomaly and the Middle Timan area