投稿时间：2021-11-02
修订日期：2021-12-29
网络发布日期：2022-03-17
中文摘要:蚀变岩帽与斑岩体关系密切,具有形成斑岩-浅成低温热液型矿床的潜力。位于浙闽交界的龟湖地区发育规模巨大的蚀变岩帽(>30 km2),形成了龟湖超大型叶腊石矿床,矿体属于岩帽的一个分带。矿床及其围岩蚀变主要由粒度微小或隐晶质的层状硅酸盐蚀变矿物组成,矿物之间差别极为细微,仅凭肉眼难以区分。短波红外光谱技术可以有效识别这些蚀变矿物的组成。因此,文章以龟湖超大型叶腊石矿床为例,通过短波红外光谱测量,对蚀变矿物进行了精细研究,通过对矿区网格化采样及短波红外光谱分析,识别出以叶腊石、钠云母、白云母、高岭石为主的17种含羟基官能团蚀变矿物,并将矿区地表蚀变划分为硅化带、高级泥化带和泥化带3个相带。在矿区范围,绢云母光谱特征参数Pos2200低值区与IC高值区主要分布在硅化和高级泥化带中,指示了较高的蚀变温度;叶腊石光谱特征参数Pos1400与Pos2160半高宽低值区与绢云母特征参数异常值区域一致。以上指标异常值区域在矿区仰天湖东南约300 m处重合,可能存在热液中心。龟湖蚀变岩帽与福建紫金山高硫型浅成低温热液矿床具有高度相似的蚀变分带特征,文章认为该蚀变岩帽具有形成斑岩-浅成低温热液矿床的潜力。
Abstract:Lithocaps are closely related to porphyry, and have the potential to find porphyry-epithermal deposits. Massive lithocaps(>30 km2) developed in the Guihu area at the border of Zhejiang and Fujian, forming the Guihu super-large pyrophyllite deposit, the ore belongs to a zone of the lithocaps. The deposits and their wall-rock alteration are mainly composed of layered silicate alteration minerals with small particle size or aphanitic, and the differences between minerals are very subtle and difficult to distinguish with the naked eye alone. Short-wave infrared(SWIR) spectroscopy can effectively identify the composition of these altered minerals. Therefore, this paper takes the Guihu super-large pyrophyllite deposit as an example, and makes a detailed study of the alteration minerals by short-wave infrared spectroscopy. The reticular sampling and short-wave infrared spectroscopic analysis of the mining area identified 17 kinds of hydroxyl-containing minerals, such as pyrophyllite, paragonite, muscovite, kaolinite, etc., and divided the surface alteration of the mining area into three phases of strong silicified zone, advanced argillitization zone and argillitization zone. Within the mining area, the low value area of the sericite mineral spectral characteristic parameter Pos2200 and the high value area of IC are mainly in the silicified and high-grade argillaceous zone, indicating a higher alteration temperature; the pyrophyllite spectral characteristic parameters Pos1400 and Pos2160 FWHM which is consistent with the abnormal value area of the sericite characteristic parameter. The abnormal value area of the above indicators coincides at about 300 m southeast of Yangtian Lake in the mining area, and there may be a hydrothermal center. Lithocaps in Guihu pyrophyllite deposit and Fujian Zijinshan high epithermal deposit have a similar alteration zone characteristics, we believe that the lithocaps have the potential of porphyry-epithermal deposit.
keywords:geology short-wavelength infrared(SWIR) hydrothermal alteration pyrophyllite sericite nonmetallic deposit
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基金项目:中国地质科学院矿产资源研究所基本科研业务费专项经费(编号:KK2014和地质矿产调查评价项目(编号:DD20201173)联合资助
引用文本：
翟世达,段士刚,孙鹏,王旭辉,张炎,梅世勇.2022.浙江泰顺龟湖叶腊石矿床热液蚀变短波红外光谱分析[J].矿床地质,41(1):189~201ZHAI Shi-da,DUAN Shi-gang,SUN Peng,WANG Xu-hui,ZHANG Yan,MEI Shi-yong.2022.Short-wavelength infrared spectral analysis of hydrothermal alteration associated with Guihu pyrophyllite deposit in Taishun, Zhejiang Province, China[J].Mineral Deposits41(1):189~201
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