桂西北林旺金矿床构造控矿规律及成矿模式探讨

Structural Ore-Controlling Law and Metallogenic Model of the Linwang Gold Deposit in Northwestern Guangxi

桂西北林旺金矿是近年来右江盆地新发现的卡林型金矿,位于乐业碳酸盐台地边缘乐业-浪全同生断裂带上。通过对矿区进行野外调查、岩矿鉴定并结合勘探成果进行综合研究,发现I号矿体群与断裂、褶皱的时空联系具有构造分带的特征,以F 1断层为界,上盘褶皱鞍部发育石英杂砂岩夹粉砂质泥岩矿体,矿体近F 1断层破碎带部位发育破碎的硅化构造岩带,F 1下盘近破碎带部位发育强烈劈理化、炭化粉砂质泥岩带,指示矿区在印支期挤压过程中,石英杂砂岩顺着先存构造薄弱面以泥岩层为滑动系统,往上部逆冲并逐渐发生褶皱,产生许多张裂隙,成为成矿流体富集的场所。林旺金矿床是层滑-褶皱构造体系与成矿流体耦合作用的产物,分析了矿床构造成矿规律,提出了以层滑-褶皱运动机制为基础的成矿模式以及成矿远景。

The Linwang gold mine is a Carlin-type gold deposit discovered in recent years,which is located at the Leye-Langquan synsedimentary fault in the margin of the Leye carbonate platform,Youjiang Basin.Combined with exploration results,detailed field geological investigations and rock ore identification indicate that the temporal and spatial relations of the ore bodies with faults and folds are featured by structural zoning.Demarcated by the fault F 1,there is quartz greywacke with silty mudstone orebodies in the fold saddle of the hanging wall of F 1.Strong cleavage and carbonization of silty mudstone belts are present in the footwall of F 1.These phenomena imply that in the Indosinian compress process,quartz greywacke upward thrust and buckled gradually along pre-existing tectonic weak plane in the mudstone layer as a sliding system,producing a lot of cracks,serving as an accumulation place of ore-forming fluid.Thus the Linwang gold deposit was formed in a layer slip-fold system with metallogenic fluid coupling.This helps determine metallogenic law,establish a genetic model and propose mineralizing prospect in the mine area.