【摘要】 铜厂金矿床位于哀牢山造山带金平古生代盖层构造单元的中南部.金矿化分布于奥陶系下统复理石碎屑岩和志留系中-上统白云岩之间的北西走向断裂破碎带中.含金矿物主要为自然金和银金矿,附着于黏土矿物或赋存于石英、黄铁矿、毒砂裂隙和胶结物的颗粒间.矿石为细脉状、浸染状和团块状构造.围岩蚀变为碳酸盐化、硅化、绢云母化等.金矿石黄铁矿δ34S为0.337‰～3.113‰,208Pb/204Pb、207Pb/204Pb和206Pb/204Pb分别为39.3814～40.1504、15.7093～15.7727和19.002～19.5492.矿区石英正长斑岩δ34S为-1.118‰～-0.161‰,208Pb/204Pb、207Pb/204Pb和206Pb/204Pb分别是39.0817～39.2278、15.653～15.6805和18.8186～18.8612.金矿石黄铁矿的硫不是来源于石英正长斑岩,铅来源于上地壳.石英正长斑岩铅为上地壳和下地壳或上地幔混合来源铅.金矿床可能是在新生代岩浆-构造作用晚期,断裂构造中循环的热液汲取上地壳沉积围岩中的金等成矿物质形成的含矿流体,在断裂构造带压力和温度较低部位通过充填和交代作用形成的.更多还原

【Abstract】 The Tongchang gold deposit is tectonically sited in middle south o f Jinping Paleozoic cover of Ailaoshan orogenic belt. Gold mineralization occurs w ithin NW-striking fault-fractures between Lower Ordovician flysch sediment and Middle-Upper Silurian dolomite. The gold-bearing minerals are native gold and electrum, which are attached to clay minerals or within crevices of quartz, pyr ite and arsenopyrite grains and in between grains of cements, occurring as veinl et, disseminated and smallmassive in ores. Carbonatization, silicification and s ericitization develop as wallrock alteration. The δ34S values of pyrite from gold ore range from 0.337‰to 3.113‰. The values of 208Pb/204Pb、207Pb/204Pb and 206pb/204Pb of pyrite from gold ore range res pectively from 39.3 814 to 40.1504, 15.7093to 15.7727 and 19.002 to 19.5492. Whi le the δ34S values of pyrite from the wallrock quartz-orthophyry range from -1.118‰to -0.161‰, with 208Pb/204Pb,207Pb/204Pb and 206pb/204Pb of pyrite f rom the quartz-orthophyry ranging from 39.0817 to 39.2278, 15.653 to 15.6805 an d 18.8186 to 18.8612,respectively. It is indicated that the sulphur of the pyrit e from gold ore is not derived from quartz-orthophyry magma fluid but sedimenta ry wallrock. The lead of pyrite from ore is derived of upper crust and that from the quartz-orthophyry is originated from upper and lower crust or upper mantle . It is inferred that gold in the Tongchang ore was deposited from gold-bearing hydrothermal fluid,which circulated along faults and extracted gold and other o re-forming matters, by infilling and replacing at low pressure and temperature site in the fault system.更多还原