This paper is the result of mineral exploration engineering.The Sansui deposit is located in the uranium metallogenic belt between central Guizhou and northwest Hunan Province. It is the first large uranium deposit discovered in Guizhou Province in recent years. The uranium deposit situates in the carbonaceous mudstone of Laobao Formation of Sinian - Cambrian and is stratified and like stratified.

Objective The purpose of this paper is to find out the ore and mineral composition of Sansui uranium deposit, explore the uranium mineralization environment, reveal the mineralization process of uranium initial enrichment, leaching, superposition and re-enrichment, and provide new information for regional metallogenic prediction, ore exploration and enrichment of this type of uranium ore-forming theory.

Methods The study on mineral mineralogy and geological characteristics of ore deposits shows that

Results (1) The Laobao Formation of uranium-bearing rocks was formed in the anoxic reduction environment of the continental margin rift and continental margin rifting during the Sinian/Cambrian transitional period. (2) The uranium ore is mainly composed of uranium mineral, iron ore, clay mineral, organic matter, dolomite, quartz (or chalcedite), barite, calcite, etc., with microcrystal-cryptocrystal structure, microcrystal-powder grain structure, layered and lamellar structure. (3) The uranium ore is rich in uranium minerals, mainly pitchblende, silica-calcined uranium ore, selenium-lead uranium ore, titanium-uranium ore, phosphorus uranium ore and water-carbon uranium, etc. They occur in the form of nano-micron granule, column (particle size < 10 microns), veinlet, or in the form of cryptocrystalline occurrence in the organic matter, iron, clay minerals and other uranium minerals. (4) The constant element in the ore were enriched in SiO₂, CaO and LOI (burning loss), which was consistent with the rich silica, calcium and organic minerals.

Conclusions The uranium source of the Sansui deposit was related to the submarine volcanic eruption, spillage during the Xuefeng period and the weathering and leaching of uranium-bearing geological bodies. Mineralization and its associated trace elements such as U, V, Mo, Cd, Se, Ni, Zn, etc. are significantly enriched, which is related to the fact that some ore-forming materials and ore-forming fluids are continuously leaching ore-forming materials in the strata during the process of submarine volcanic eruption and spill.