Geochemical controls on the formation of unconformity-type Au–U deposits (Northern Transbaikalia)

Abstract

This study provides geochemical, mineralogical, and isotope data for rocks and ores from Lower Proterozoic black shale formations of the Kodar–Udokan structural and formational zone, which host the Khadatkanda gold—uranium deposit. The results indicate that the uranium and gold mineralizations were formed at different times in relation to different geodynamic settings. The gold mineralization is associated with the inception of the Syulban fault and has a juvenile source. The later Th–U mineralization originated during tectonic rejuvenation of the Syulban fault zone, while the sources of radioactive elements were presumably the underlying sediments of the Kodar Group, which are widespread throughout the area of the Baikal mountain region (BMR). Based on the above results, the Au–U mineralization in the study area can be recognized as unconformity-type deposits, analogous to the well-known deposits of Australia and Canada. In this connection, the Baikal mountain region has a good potential for the discovery of Au—U deposits.