In support of an in-situ leaching experiment, five holes drilled into a copper oxide deposit have been logged with geophysical and geochemical tools developed for use in the petroleum industry. When combined with geological description, chemical analyses, and mineralogical data from core and cuttings, the logs provide information regarding the alteration, fracturing, copper distribution, porosity, and permeable zones. Correlations among sonic velocity, rock strength from mechanical tests on core, and alteration indicators from neutron and potassium logs demonstrate a close link between the state of alteration and the mechanical state of the rock. Neutron activation, natural gamma-ray, and density logs, in combination, correlate so well with copper assays that log-based prediction of copper content is possible; in addition, an estimate of whole-rock mineralogy is presented in log format. Based on comparisons of flow logs and acoustic logs obtained in the same holes, reductions in acoustic velocity appear to be the best indicators of permeability increases.

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