摘要
本文通过对广西大厂矿田长坡—铜坑超大型锡—多金属矿床的矿石组构研究,认为该矿床兼具同生(成岩)和后生的双重成矿地质特征,是一个复合成固矿床。根据矿石组构和矿物组分特征,可将该矿床划分为两类矿体,即层状含锡硫化物矿体和脉状锡石—硫化物矿体。层状矿体具同生—成岩成矿的属性,矿物组合比较简单,其成因可能与晚泥盆世榴江期海底含矿热水活动有关;脉状矿体则具后生成矿的属性,矿物组合较复杂,其成因与燕山晚期花岗岩浆活动有关。这两类不同成因的矿体密切伴生的现象表明,该矿床是一个早期热水沉积成矿和后期岩浆热液叠加再富集成矿的复合成因超大型矿床,具有多期多阶段及成矿物质多来源的成矿特点。还对该矿床的成矿期和成矿阶段提出了新的划分方案。
Based on the study of ore fabrics of Changpo-Tongkeng superlarge tin-polymetallic ore deposit of Dachang Ore Field, Guangxi, the author has discovered that the ore deposit possesses both syndiagenesis and anadiagenesis geological characteristics, and is a complex-origin deposit. According to the ore fabrics and the mineral assemblages, this ore deposit can be divided into two types: stratiform stanniferous sulfide orebody and veinlike cassiterite-sulfide orebody. The stratiform orebody is characterized by syndiagenesis-diagenetic mineralization and simple mineral assemblages, its origin was related to ore-bearing hydrothermal occuring on sea floor during Liu Jiang period, the veinlike orebody is characterized by anadiagenesis and complex assemolages, its origin had a close relation with granomagma activity during Yanshan period. The closely associated phenomenon of the two different origin orebodies shows: this ore deposit is a complex superlarge ore deposit consisted of early-period hydrothermal deposited mineralization and late granomagma hydrothermal superimposed-reenriched mineralization, and possesses the minerogenatic character of polyperiod, polystage and polygenesis.
