内蒙古中部大青山新地沟-卯独庆金矿床的构造-蚀变-成矿作用  

Tectonic-alteration-mineralization of the Xindigou-Maoduqing gold deposits in the Daqing Mountains, Inner Mongolia, China

作　　者：赵维宽 徐九华[1] 席忠 李德亭[1] 贾长顺[1] 

机构地区：[1]北京科技大学资源工程系,北京100083 [2]内蒙古第一地质矿产勘查开发院,内蒙古呼和浩特土默特左旗010010

出　　处：《地质通报》2008年第4期575-583,共9页Geological Bulletin of China

基　　金：内蒙古自治区重大地质科技项目(编号:内地研200415003);国家自然科学基金项目(编号:40672060)资助

摘　　要：新地沟和卯独庆金矿赋存于新太古界色尔腾山群柳树沟岩组中,是典型的与韧性—脆韧性剪切变形有关的绿岩型金矿。构造-蚀变岩石的主要类型有千糜岩化石英绢云片岩、千糜岩化绿泥绢云片岩、糜棱岩化绿泥石英片岩、绢云绿泥长英质糜棱片岩、长英质碎裂岩、黄铁绢英岩质构造片岩等。构造-蚀变岩石的岩石地球化学特征与中基性火山岩类似,其稀土元素总量∑REE(44.9×10-6～155.4×10-6)、LREE/HREE比值(7.0～26.1)、δEu(0.6～1.2)也显示了中基性火山原岩的特点。构造-蚀变-成矿流体的特征为富CO2的低盐度的较高密度的流体,具有造山型金矿的特点。前寒武纪绿岩带建造变质镁铁质火山岩分布的地区构造-蚀变作用强烈的地段是重要的找矿有利地区。The Xindigou and Maoduqing gold deposits, occurring in the Liushugou Formation of Neoarchean Serteng Shan Group, are typical greenstone-type gold deposits related to ductile-brittle shear deformation. Tectonic-altered rocks are mainly phyllonitic quartz-sericite schist, phyllonitized chlorite-sericite schist, mylonitized chlorite-quartz schist, sericite-chlorite felsic mylonitic schist, felsic cataclasite and pyrite-sericite-quartz tectonic schist. The geochemical characteristics of tectonic-altered rocks are similar to those of inter- mediate-basic volcanic rocks. Their ∑REE （44.9-155.4×10^-6）, LREE/HREE （7.0-26.1） and δEu （0.6-1.2） of tectonic-altered rocks also resemble those of intermediate-basic volcanic rocks. Tectonic-alteration-mineralizing fluids are characterized by low salinity, high density and CO2-rich fluids, with typical features of orogenic gold deposits. The important prospecting areas are zones of strong tectonic alteration in regions where metamorphic mafic volcanic rocks in Precambrian greenstone formations are widely distributed.

关 键 词：构造一蚀变 成矿流体 稀土元素 大青山 内蒙古 

分 类 号：P618.51[天文地球—矿床学]