Influence mechanism of palaeoclimate of uranium-bearing strata on mineralization: A case study from the Qianjiadian sandstone-hosted uranium deposit, Songliao Basin, China

Abstract

Paleoclimate, uranium reservoirs, interlayer oxidized zones and ore bodies of the Upper Cretaceous Yaojia Formation in the Qianjiadian uranium deposit are illustrated in order to reveal effects of palaeoclimate on uranium mineralization. The Yaojia Formation is divided into six units: SQK2y-LST, SQK2y-EST (Pss1), SQK2y-EST (Pss2), SQK2y-EST (Pss3), SQK2y-HST (Pss1) and SQK2y-HST (Pss2). Paleoclimate of the SQK2y-LST, SQK2y-EST (Pss1), SQK2y-EST (Pss2), SQK2y-EST (Pss3), SQK2y-HST (Pss1) and SQK2y-HST (Pss2) is south subtropical semi-arid and sub-humid, tropical sub-humid, south subtropical semi-arid, central subtropical semi-arid and sub-humid, south subtropical semi-arid, and south subtropical semi-arid, respectively. In the same temperate zones, thickness and TOC contents of the uranium reservoirs in the humid climates are larger and higher respectively, thickness and area of the corresponding interlayer oxidized zones are both larger, and thickness, uranium amount per square meter and area of the corresponding ore bodies are all larger than those in the arid climates. In the same humidity zones, thickness and TOC contents of the uranium reservoirs in the warm climates are larger and higher respectively, thickness and area of the corresponding interlayer oxidized zones are both larger, and thickness, uranium amount per square meter and area of the corresponding ore bodies are all larger than those in the cold climates. This study reveals that hot and humid paleoclimate is favorable for mineralization of sandstone-hosted uranium deposits, and paleoclimate has a restriction on geometry and composition of uranium reservoirs, which may affect scales and distribution of interlayer oxidized zones and uranium ore bodies.