甘肃阳山超大型卡林-类卡林型复合式金矿床特征  

Characteristics of the superlarge Yangshan Carlin and Carlin-like compound type gold deposit in Gansu

作　　者：张复新[1] 侯俊富[1] 张存旺[1] 李晶[2] 杨荣生[3] 

机构地区：[1]大陆动力学国家重点实验室(西北大学),西北大学地质学系,陕西西安710069 [2]中国科学院广东地球化学研究所,广东广州510640 [3]北京大学地球与空间科学学院,北京100087

出　　处：《中国地质》2007年第6期1062-1072,共11页Geology in China

基　　金：国家自然科学基金项目(40572065);国家重大基础研究规划项目(2006CB403502)共同资助。

摘　　要：阳山金矿于世纪之交勘查并扩大为超大微细浸染型金矿,矿床形成受地层、浅成花岗斑岩、韧-脆性剪切构造及热液活动的多种因素的叠加与改造控制,研究认为矿床具有卡林型和类卡林型两种矿化类型特点,卡林型矿化于韧性剪切早、早—中期阶段和晚期阶段,分别出现含砷黄铁矿-毒砂-次显微金-白云石-石英矿化组合及黄铁矿-辉锑矿-石英方解石矿化组合,及Au-As-Sb-Hg的成矿地球化学组合;类卡林型矿化出现在脆性中—晚期阶段,以黄铁矿-毒砂-自然金-碲铋矿-白云石-石英矿化(含黄铜-闪锌-方铅矿)组合为特征,及Au-As-Cu-Pb-Zn-Te-Bi成矿地球化学组合。阳山复合式金矿含矿地层中沉积成岩黄铁矿δ34S为-24.6‰～-29.0‰,早期—早中期韧-脆性剪切金属硫化物矿化产物δ34S值为5.0‰～7.0‰,中—晚期蚀变花岗斑岩中金属硫化物矿化产物δ34S值为-2.9‰～-2.1‰,显示地层中生物硫、强变形造山带地壳硫、少量岩浆硫混入的多源特征。流体包裹体氢氧同位素与硫同位素近同步特征,成矿热液显示地下流体、强烈改造水和少量岩浆水的混合。The Yangshan gold deposit is a very finely disseminated gold deposit, which was explored at the turn of the century and expanded into a superlarge deposit. The deposit was controlled by superposition and modification of many factors such as strata, hypabyssal granite-porphyry, brittle-ductile shear and hydrothermal activities. The gold deposit has the characteristics of both Carlin type and Carlin-like type mineralization. The Carlin-type mineralization occurred during the early, early-middle and late stages of ductile shearing, when there appeared the As-bearing pyrite-arsenopyrite-submicroscopic gold-dolomite-quartz assemblage and pyrite-stibnite-quartz- calcite assemblage, as well as the Au-As-Sb-Hg geochemical assemblage. The Carlin-like type mineralization took place during the middle-late stage of brittle shearing, which is characterized by the pyrite-arsenopyrite- native gold-teUurobismuthite-submicroscopic gold-dolomite-quartz assemblage （with chalcopyrite, chalcopyrite and chalcopyrite） and the Au-As-Cu-Pb-Zn-Te-Bi geochemical assemblage. The δ34S values are -24.6%o to -29.0%o for sedimentary diagenetic pyrite in ore-bearing strata of the gold deposit, 5.0 to 7.0%o for the metal sulfide formed during the early and early-middle stage of brittle-ductile shearing and -2.9 to -2.1%o for the metal sulfide in altered granite porphyry of the middle-late mineralization stage, suggesting the multi-source features of mixing with biogenic sulfur in strata, crustal sulfur in strongly deformed orogenic belts and a little rnagmatic sulfur. The hydrogen and oxygen isotopes in fluid inclusions show nearly sympathetic variations with δ 34S, and hydrothermal ore fluids are the mixture of underground fluids, strongly modified meteoric water and a little magmatic water.

关 键 词：叠加与改造成矿作用 卡林-类卡林复合型金矿 阳山 西秦岭 

分 类 号：P618.51[天文地球—矿床学]