中国重晶石矿床的成因类型

GENETIC TYPES OF BARITE DEPOSITS IN CHINA

根据已知的矿床实例,依据矿床的成矿机理、产状、矿体与围岩的相互关系等,将中国重晶石矿床分为五个成因类型:①沉积型重晶石矿床;②层控脉状型重晶石矿床;③脉状热液型重晶石矿床;④火山沉积型重晶石矿床;⑤残坡积堆积型重晶石矿床。

On the basis of the minerogenetic mechanism, modes of occurrence and relationship between orebodies and wall rocks. the barite deposits in China might be gnetically grouped into five types.1. The sedimentary type barite deposit: It is the most important type in China and, according to the difference in sedimentary envoronment, can be further divided into two subtypes: marine facies and inland lacustrine facies sedimentation. The main features of this type of deposits are(1) the orebodies occur in stable or relatively stable stratiform or stratoid forms along a certain stratigraphic horizon and(2) the texture and structure of the ore show obvious sedimentary characteristics.2. The stratabound veinlike barite deposit: Orebodies appear in groups and zones, occur in the filling form within fracture zones or fissure zones of the wall rocks and are controlled by certain strata. Ore materials are derived from strata, and minerogenesis has nothing to do with volcanic rocks.. The veiulike hydrothermal barite deposit: It has direct genetic connection with igneous rocks and is a post-magmatic mesothermal-epithermal deposit.4. The volcanic sedimentary barite deposit: The ore bed is consistent with wall rocks, the texture and structure of the ore show characteristics of volcanic sedimentation, and the minerogenesis is related to volcanism.5. The residual-slope accumulation type barite deposit: It occurs near the primary veinlike barite deposit and is genetically a residual accumulation deposit after the weathering of the primary barite deposit.