中文摘要:滩间山金矿床产丁中元古界万涮沟群碳质糜棱片岩和华力西晚期侵入岩中。矿床是在热水沉积、区域变质和热变质的预富集基础上,与区域进变质型绿片岩相韧性剪切带的退化演化同步,经历了脆韧性、韧脆性和脆性剪切变形成矿阶段的演化,并遭受华力西晚期侵入岩浆活动相伴的热液成矿作用的叠加改造形成的。不同时期、不同成矿作用的叠加和多种有利因素的结合控制了滩间山金矿床的形成。经生产实践证实,具有形成大型金矿床的多种有利成矿地质条件。
Abstract:Located on the northern margin of Qaidam massif, the Tanjianshan gold deposit occurs in the carbonaceous mylonite schist of Wandonggou Group of Mesoprotcrozoic Jixian System as well as in the Late Variscan intrusive rocks. Hydrothermal deposition, regional metamorphism and thermal metamorphism led to the primary enrichment of the ore-forming materials. The retrograde metamorphism of the greenschist facies brittle-ductile shear deformation and metamorphic zone, in conjunction with the brittle-ductile,ductile-brittle and brittle shear deformation subjected to the superimposition of Late Variscan magmatic intrusion, resulted in the formation of the deposit. The I/ate Variscan ore-forming process seems to have been the most important metallogenic epoch under the condition of ductile-brittle shear deformation. Fluid inclusion studies show that ore-forming fluids were composed mainly of Na-rich metamorphic water and K-rich magmatic water. REE contents and REE patterns of ores and host rocks suggest that ore-forming materials came from carbonaceous mylonite schist and intrrusive rocks. The strata, intrusive rocks, ores and pyrite in the ore district show good affinily in lead isotope composition. The lead isotope composition of pyrite, the most important ore mineral, is cluite similar to that of the Late Variscan intrusive rocks , indicating that the Late Variscan magmatic intrusion must have made greater contribution to ore-forming materials than the strata. Related to repeated opening-closing evolution of the regional crust, the Tanjiangshan gold deposit is a polygenetic composite deposit. The superimposition of different ore-forming processes of different periods and the combination of various favorable factors were responsible for the formation of the Tanjianshan gold deposit. The ore deposit was predicted to be large in size, and this has been proved to be true in practice.
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基金项目:地矿部定向科研项目(直科定92-35)
引用文本:
于风池, 马国良, 魏刚锋, 王永祥, 梅安静.1998.青海滩间山金矿床地质特征和控矿因素分析[J].矿床地质,17(1):47~56.1998.Geological characteristics and ore-controlling factors of the Tanjianshan gold deposit, Qinghai Province[J].Mineral Deposits17(1):47~56
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