八蒙辉锑矿的标型特征与矿床成因

Typomorpic Characteristics of Bameng Stibnite and Genesis of the Ore Deposit

辉锑矿是贵州省八蒙锑矿床的主要矿物。本文研究了辉锑矿的产状、化学成分、物理性质、光学性质和晶体结构标型特征以及辉锑矿的同位素组成和石英的流体包裹体特征，指出八蒙锑矿床是大气降水成因的热液脉状矿床。

The Bameng antimony deposit Iocated in southoastern Guizhou is a medium-size vein type deposit,with its orebodies controlled by the NE-and NNE-trending faults that belong to the subsidiary fractures of the Songtao-Rongjiang deep faulted zone.The present paper deals mainly with fypomor-phic characteristics of stibnite,the most important ore mineral in the depo-sit,in such aspects as chemical composition,physical property,optical pro-perty,crystal structure,isotopic composition and quartz inclusions,with a dis-cussion given on the genesis of the Bameng antimony deposit.Typomorphic studies show that the stibnite is rich in Pb and poor in As,Hg and Ag,and its unit cell parameter a_0 is larger than b_0, attributed probably to the reason that Pb￣(2+) has occupied some lattice sites of Sb￣(3+)in a_0 direction.Surfur and lead isotopic data have led the author to consider that the ore-forming materials were mainly derived from the wall rock-epimetamor-phic rock of Xiajiang Group.Fluid inclusion studies show that the ore-for-ming solution of the Bameng antimony deposit must have been a kind of meteoric hydrothermal solution with low salinity and weak acidity.It is therefore concluded that the Bameng antimony deposit is of meteoric hydro-thermal vein type.