BARITE AND FLUORITE STRATABOUND DEPOSITS IN SOUTHEASTERN SICHUAN AND ORE-CONTROLLING GEOLOGICAL CONDITIONS

Barite and fluorite deposits in southeastern Sichuan are widespred, occurring mainly in Pengshui, Qianjiang and Youyang counties. They form a very promising metallogenic province（belt）. The province（belt） is mainly controlled by NNE- and NE-trending folds and fractures. The ore-bearing beds consist of limestone of the Lower Ordovician Honghuayuan Formation. Controlled by NW-or NNW-trending tenso-shear fractures, the deposits occur as steep-dipping veins. The mineral assemblage is simple, composed mainly of barite, fluorite and calcite. They have the characteristics of typical stratabound deposits. The formation of the deposits is related to the brines formed by the underlying Middle and Lower Cambrian evaporites. The characteristics of the barite and fluorite deposits in the area are very similar to those of mercury and leadzinc mineralizations. In terms of space the barite and fluorite zone-lead and zinc zone-mercury zone may be distinguiched. They were formed roughly in the same metallogenic epoch（Yanshanian stage）.