鄂东南矿集区典型矽卡岩-斑岩矿床蚀变矿物短波红外(SWIR)光谱研究与勘查应用  

The short wave infrared( SWIR) spectral characteristics of alteration minerals and applications for ore exploration in the typical skarn-porphyry deposits,Edong ore district,eastern China

作　　者：陈华勇[1,2] 张世涛 初高彬 张宇 程佳敏[1,3] 田京[1,3] 韩金生 CHEN HuaYong;ZHANG ShiTao;CHU GaoBin;ZHANG Yu;CHENG JiaMin;TIAN Jing;HAN JinSheng(CAS Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China;MOE Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring,Central South University,Changsha 410083,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China)

机构地区：[1]中国科学院广州地球化学研究所矿物学与成矿学重点实验室,广州510640 [2]广东省矿物物理与材料研究开发重点实验室,广州510640 [3]中国科学院大学,北京100049 [4]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,长沙410083 [5]中南大学地球科学与信息物理学院,长沙410083

出　　处：《岩石学报》2019年第12期3629-3643,共15页Acta Petrologica Sinica

基　　金：湖北省地质局科技项目(KJ2018-5);国家自然科学基金项目(41725009);国土资源部公益性行业科研专项项目(201511035)联合资助

摘　　要：鄂东南矿集区是我国著名的矽卡岩-斑岩型铜铁金矿床产区,研究程度较高,近年来矿产勘查进入了深部找矿的新阶段,需要较新的勘查方法与思路。本文介绍了利用短红外光谱(SWIR)技术,对鄂东南典型的铜绿山矽卡岩型Fe-Cu-Au矿床、鸡冠嘴矽卡岩型Cu-Au矿床、铜山口矽卡岩-斑岩型Cu-Mo-W矿床进行的蚀变矿物综合研究最新成果。在确定蚀变矿物组合类型、形成期次、蚀变分带的基础上,揭示了主要蚀变矿物SWIR特征值的指示规律,并进一步提取各个矿床的蚀变矿物SWIR勘查标志,如铜绿山矿床富Fe绿泥石(Pos2250>2253nm)、高结晶度高岭石族(Pos2170>2170nm,Dep2170>0.18)、白云母族-蒙脱石异常Pos2200值(>2212nm或<2202nm)、高岭石、迪开石及皂石的大量出现,可以作为铜绿山铜铁金矿床有效的蚀变矿物勘查标志;鸡冠嘴矿床白云母族-蒙脱石Pos2200特征值的高值(>2209nm)区域对矿体位置具有较好的指示性;铜山口矿床绿泥石的高Fe-OH吸收峰位值(Pos2250>2249nm)和高Mg-OH吸收峰位值(Pos2335>2333nm)的高频出现,可以作为铜山口铜钼钨矿床的有效勘查标志。这些研究成果表明蚀变矿物可以为鄂东南矿集区提供有效的勘查标志体系,同时,这些最新的勘查标志也在铜绿山铜铁金矿床得到了初步的应用和验证。The Edong ore district in southeastern Hubei Province is a famous skarn-porphyry ore deposits region in China. In recent years,mineral exploration in the deep area has been paid attention,which requires new exploration methods and approaches. In this study,the latest comprehensive research results for the alteration minerals in the Tonglvshan Cu-Fe-Au skarn deposit,Jiguanzui Cu-Au skarn deposit and Tongshankou Cu-Mo-W skarn-porphyry deposit were presented,especially based on the application of the short wave infrared spectrum( SWIR). On the basis of the assemblages of alteration minerals,paragenesis and alteration zoning,trends of the main alteration mineral SWIR features were identified,and criteria for exploration were further extracted for each skarn(-porphyry)deposit. For instance,high Pos2250 values( > 2253 nm) of Fe-rich chlorite,high crystallinity( Pos2170 > 2170 nm,Dep2170 > 0. 18)of kaolinite group,anomalous high and low Pos2200( < 2202 nm,or > 2212 nm) values of white mica-montmorillonite,emerging of kaolinite,dickite and saponite,can be used as vectors towards mineralization center in the Tonglvshan Cu-Fe-Au deposit;the high Pos2200( > 2209 nm) values of white mica-montmorillonite can be used as vectors for the Jiguanzui Cu-Au deposit;and the high frequency of chlorite Pos2250( > 2249 nm) and Pos2335( > 2333 nm) can be used as vectors for the Tongshankou Cu-Mo-W deposit.The variations of SWIR spectral features of these phyllosilicate minerals are mainly related to the chemical compositions and temperature of hydrothermal fluid and surrounding rocks. The occurrences of dickite and kaolinite in the deep area at Tonglvshan indicate that the hydrothermal fluid may have experienced the evolution from high-temperature,alkaline to medium-low-temperature,intermediate-acid conditions. These research findings show that the alteration minerals can provide effective exploration indicators for the skarn-porphyry deposits in the Edong ore district,and these results have been preliminarily applied and verified in the

关 键 词：蚀变矿物 SWIR 蚀变分带 矽卡岩-斑岩型矿床 勘查标志 鄂东南 

分 类 号：P622.2[天文地球—地质矿产勘探]