Depth of lithochemical searches on eluvio-deluvial scattering halos

Abstract

In prospecting lithochemical survey on residual eluvio-deluvial scattering halos, samples are taken, as a rule, from a depth of 15-20 cm, immediately below the vegetation layer. At the same time, it is known that metal concentration in the halo decreases with increasing thickness of deluvium. Obviously, when the thickness of the deluvium is significant, the metal concentration in the subsurface layer may become below the sensitivity limit for the determination of this element. With very sensitive methods of sample analysis, the depth of the lithochemical survey will be limited by the accuracy of the analysis and the irregularity of the useful metal content in the bedrock containing the ore body. On this basis, in lithochemical survey it is necessary to have at least a rough idea of the depth of the method - the limiting thickness of eluvium-deluvium, at which in the subsurface layer metal concentrations will still be sufficient for reliable detection of the halo.