Subbackground halos in hydrothermal uranum deposits

Results are described of investigations into the statistic structure of initial halos of hydrothermal uranium deposits and of developing new methods for fixation of the boundaries of these halos. Gamma logging data served as initial, factual material. Zones of the so-called subbackground halos are found in the periphery of initial halos of hydrothermal deposits within which the uranium concentrations do not exceed the background level, while the inhomogeneity parameters of their spatial distribution are anomalous as compared with the background. The results of mineral-geochemical and statistic analysis permit to suppose that the formation of subbackground halos is connected with a local uranium redistribution under the effect of hydrothermal solutions in the peripheral range of the ore formation zone. The subbackground halo is a new structural element in the geochemical field placed over the background field of concentrations and formed by way of the latter redistributions