摘要
文章采用微量元素 (包括稀土元素 )地球化学示踪方法 ,着重讨论了金大规模成矿的物质来源、含矿流体来源及含矿流体运移的能量问题。认为湘东北地区金多金属矿床成矿物质和含矿流体具多来源 ,大规模花岗质岩浆活动能为成矿元素的活化和成矿流体运移提供巨量能源 ;成矿物质一部分源于深部含矿热液 ,可能与富铅、富氯、中高温 (3 2 0℃左右 )、相对还原的酸性环境下的气成热液有关 ,而冷家溪群及相关地层金多金属成矿物质在热液活动和动力变质作用下的活化迁移有利于金多金属的大规模成矿。侏罗纪以来 ,岩石圈地球动力学转折及伴随的热液作用和动力变质作用对区内金多金属成矿起重要的作用 ,而岩浆作用、动力作用和 /或热液活动影响程度的可能差异 ,导致了金多金属矿床具有不同的成矿特点。
Northeastern Hunan Province located in the center of Jiangnan orogenic belt has a series of Au, Cu, Co, Pb, Zn, (Co), Ag polymetallic deposits. Using geochemica l tracing of trace elements (including REE), this paper has analyzed the metallo genic material source, ore_bearing fluid source and energy source for the moveme nt of ore_bearing fluids which resulted in large_scale gold mineralization. The authors hold that metallogenic materials and ore_bearing fluids for gold ploymet allic deposits were derived from several sources. Early Yanshanian granites and Mesoproterozic Lengjiaxi Group might not provide metallogenic materials for larg e_scale gold mineralization . Nevertheless, large_scale granitic magmatism in Early Yanshanian period probably provided considerable energy for the movement of ore_bearing fluids. Metallogenic materials derived mainly from ore_bearing hy drothermal fluids might have been related to Pb_ and Cl_enriched pneumatolito_hy drothermal fluids at somewhat higher temperature (about 320℃) and in a relative ly reductive acid environment. They were favorable for the reactivity and moveme nt of gold_polymetallic materials in Mesoproterozoic Lengjiaxi Group or in corre lated strata to form large_size gold_polymetallic deposits. Geodynamic transform ation, synchronous hydrothermal activity and dynamic metamorphism were important factors for gold metallogeny in northeastern Hunan Province. However, magmatism , dynamism and/or hydrothermal activity might exhibit varied behaviors in northe astern Hunan Province, and hence different gold polymetallic deposits might ha ve different metallogenic features.
出处
《矿床地质》
CAS
CSCD
北大核心
2004年第1期39-51,共13页
Mineral Deposits
基金
国家科技攻关项目 ( 2 0 0 1BA6 90A_0 7_0 1 )
中国科学院知识创新重要方向性项目 (KZCXZ_SW_1 1 7)
湖南省自然科学基金项目( 0 3jjy30 6 6 )的资助
关键词
地球化学
示踪
成矿元素
成矿流体
微量元素
geochemistry, geochemical tracing, gold ploymetalli c ore_forming geochemistry, Yanshanian intracontinental collision orogen, northe astern Hunan Province
