湖南省桃江县板溪锑矿床地质特征研究

板溪锑矿床位于桃江板溪锑矿成矿带内,开采历史悠久,但对区域地质和矿床地质缺乏深入研究。为了在区域上进一步寻找该类型锑矿,在充分收集前人资料和野外调研的基础上,总结区域地质、矿床地质特征,深入研究控矿因素和成矿时代。结果表明: 锑矿多分布于区域性大断裂旁侧次级断裂与背斜交汇处,深断裂控制金锑成矿带的展布,矿体主要产于NW向、NE向、近EW向、NNW向和NNE向次级断裂中; 区域锑矿的形成开始于加里东期,在燕山期达到高峰。矿区背斜或背斜倾伏端控制了矿床的定位,而背斜中的次级褶皱、断裂、层间破碎带及倾伏端等控制了矿体。矿体主要赋存于前寒武纪冷家溪群、板溪群浅变质岩系中,其次赋存于南华纪—志留纪、泥盆纪—石炭纪的碎屑岩及碳酸盐岩中; 围岩蚀变主要有毒砂化、黄铁矿化、硅化、绢云母化、绿泥石化、碳酸盐化等; 矿石自然类型有石英-辉锑矿矿石、黄铁矿-石英-辉锑矿矿石、毒砂-黄铁矿-石英-辉锑矿矿石、碳酸盐-石英-辉锑矿矿石; 矿床成矿时代属燕山期。研究成果为进一步开展板溪锑矿床找矿提供借鉴和指导作用。

Geological characteristics of Banxi antimony deposit in Taojiang County of Hunan Province

Banxi antimony deposit is located in the Banxi antimony metallogenic belt in Taojiang County, with long exploitation history but little investigation of reginal and deposit geology. In order to find out more this type of antimony deposits in this region, on the basis of previous data and field investigation, the authors summarized the regional geology and the deposit geological characteristics, and deeply studied the ore-controlling factors and ore-forming era. The results show that antimony deposits are mostly distributed at the junction of secondary faults and anticlines beside regional large faults, and the distribution of gold-antimony metallogenic belts is controlled by the deep faults. Orebodies are mainly formed in secondary faults of NW, NE, EW, NNW and NNE groups. The formation of regional antimony deposits began in Caledonian and reached the peak in Yanshanian. The dip end of anticline or anticline in the mining area controls the location of the deposit, while secondary folds, faults, interlayer fracture zones and dip ends in the anticline control the ore body. Orebodies mainly occurred in Lengjiaxi Group of Precambrian and low-grade metamorphic rock series of Banxi Group, also in clastic and carbonate rocks of Nanhua-Silurian and Devonian-Carboniferous. The wall rock alteration mainly includes arsenopyrite, pyritization, silicification, sericitization, chloritization and carbonatization. Natural type of ore has quartz -stibnite ore, pyrite-quartz-stibnite ore and arsenopyrite-pyrite-quartz-stibnite ore, carbonate-quartz-stibnite ore. The metallogenic epoch of the deposit belongs to Yanshan period. These results will provide reference and guidance for the further ore prospecting of antimony deposits in Banxi area.