摘要
This paper analyzed the metallogenic epoch, ore-forming material source, metallogenic enviromnent, and ore-controlling factors of the Yushan bauxite ore deposit in Xin' an County, Henan Province. It is suggested that the Yushan bauxite ore deposit formed in the early Permian. Its ore -forming material sources are weathered products, which mainly came from aluminum silicate rocks of the paleouplift, and a small mount were derived from the underlying Middle Ordovician Majiagou Group carbonate rocks in western Henan Province. The three periods are ore body emplacement, burial, transformation and preservation ; the five stages are material source preparation, transportation, syngenesis, dlagenesis, deuterogenic stage, weathering and epigenesis. A metallogenic model of bauxite (clay) deposits as "paleouplift weathered + clastic and chemical deposits" is put forward. Its principal metallogenic mechanism is mechanical and chemical differentiation.