| 中国含金矽卡岩矿床的分布和主要地质特征 |
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| 引用本文：.1997.The distribution and geological characteristics of auriferous skarn deposits in China[J].Mineral Deposits,16(3):193~203 |
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| 基金项目:国家自然科学基金资助项目(49573184) |
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| 中文摘要:矽卡岩金矿床主要分布于中国东部，特别是在长江中下游地区，并常和矽卡岩铜（铁或多金属）矿床共生。它们产生的有利构造环境为地台地缘的拗陷和褶皱带以及地台内部的深大断裂附近地区。主要控矿地层为石炭-二叠纪和三叠纪碳酸盐岩。有关侵入岩为钙-碱性闪长岩、石英闪长岩、石英二长闪长岩、花岗闪长岩、二长花岗岩及其浅成相，大多属燕山期。含金矽卡岩以钙矽卡岩为主，镁矽卡岩次之。在矽卡岩及其邻近的围岩中叠加有较强的退化热液蚀变，并常伴有Cu、Au、Fe、Mo、Pb、Zn、Ag等矿化，显示明显的交代分带。总的矿化分带序列为：Fe(Cu)→Cu(Mo) →Cu、Au→Au→Au、Pb、Zn。在许多矿床中，发现有碲化物、铋化物和硒化物。因此，Cu、Au、Te、As、Bi、Pb、Zn、Ag、Se等元素在矽卡岩金矿床中相对富集，并成为重要的地球化学找矿标志。 |
| 中文关键词:矽卡岩金矿床 分布 地质特征 分带 中国 |
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| The distribution and geological characteristics of auriferous skarn deposits in China |
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| Abstract:In the past decade, progress has been made in the exploration of gold skarn deposits in China and some large deposits have been discovered, such as Jiguanzui and Jilingshan in Hubei Province and Xinqiao in Anhui Province. The reserves of gold skarn deposits account for about 20% of the total gold reserves in China, indicating that auriferous skarn deposits now constitute one of the major types of gold deposits in China. Gold skarn deposits may be further divided into two subtypes: independent gold skarn deposits and associated gold skarn deposits. They are mainly distributed in the eastern part of China, especially in the middle-lower reaches of the Yangtze River, and arc usually associated with copper (iron or polymetal) skarn deposits. Their favorable tectonic settings arc depressions and fold belts of plat form margins as well as areas near deep faults within the plat form. The related intrusives are chiefly calc-alkaline diorite , quartz diorite , quartz monzodiorite. Granodioritc, monzogranite, and rocks of their hypabyssal facies. Most of them arc of Yanshanian age. According to the strontium and oxygen isotope data and REE distribution patterns of some major gold skarn deposits, the magma of relate intrusives mainly came from the upper mantle, and might have been contaminated by silicic crustal materials. The auriferous skarn may be calcic or magnesian, the former being predominant. Oritlie skarns and their adjacent wall rocks arc usually superimposed strong retrograde hydrothermal alterations, such as epidotization, actinolitization, silicification, chloritization, carbonatization, serpentinization, sericitization and talcization, which are usually associated wit h Au, Cu, Fe, Mo, Pb and Zn mineralization, showing distinct metasomatic zoning. The zonality of the major gold skarn deposits is Fe(Cu) →Cu(Mo) →Cu, Au→Au→Au, Pb, Zn. In many deposits, tellurides, bismuthids and selenides are identified. Therefore, Cu, Au, As, Te, Bi, Co, Zn, Pb and Ag are more specific metallic elements in gold skarn deposits and are referred to as important geochemical ore-searching indicators. The study of fluid inclusions and the compositions of coexisting pyroxenes and garnets suggest that auriferous skarns were formed by solutions with rather high oxygen fugacity and lower acidity. |
| keywords:skarn gold deposit, distribution, geological characteristic, zonaliy, China |
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