黔西南高岭萤石矿床地质-地球化学特征与成因
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摘要
黔西南州是贵州省内萤石矿产资源相对集中区之一,目前已发现萤石矿床(点)若干,主要分为独立型和共(伴)生型两类,后者与金矿床、锑矿床等低温热液矿床共(伴)生,属于华南大面积低温成矿域重要组成部分之一。目前对独立型萤石矿床的研究还很薄弱,严重制约了对这一稀缺性战略非金属矿产成因的理解。高岭是晴隆锑矿床外围近年来新发现的一个独立型萤石矿床,伴有少量锑矿化,是研究本区独立型萤石矿床成因的理想对象。本文在深入开展其矿床地质研究的基础上,采用萤石颗粒微钻取样技术和萤石微波消解方法,获得了MC-ICPMS高精度萤石Pb和Sr同位素组成数据。结果显示,萤石的Pb同位素比值变化较大,~(206)Pb/~(204)Pb=18.5107～20.1915,~(207)Pb/~(204)Pb=15.7075～15.8298,~(208)Pb/~(204)Pb=36.6625～38.6938,明显富集放射性成因Pb,暗示其源区富放射性成因Pb或流经了富放射性成因Pb的源区;萤石的Sr同位素比值变化范围较窄,87Sr/86Sr=0.707845～0.707968,略高于赋矿的二叠系茅口组灰岩(~(87)Sr/~(86)Sr=0.70679～0.70682)和峨眉山玄武岩(~(87)Sr/~(86)Sr=0.70480～0.70647),也略高于二叠纪海水Sr同位素比值(~(87)Sr/~(86)Sr=0.70684～0.70820),表明成矿流体相对富集放射成因Sr,暗示有富放射性Sr的源区贡献,即成矿物质/流体来源或流经富放射性成因Sr的源区。通过对比,本文认为高岭萤石矿床成矿物质/流体具有多来源特征,其与晴隆锑矿床同属于一个成矿系统,是大面积低温成矿晚期产物。
The southwestern Guizhou is one of the relatively concentrated areas of fluorite resources in Guizhou Province.At present, many fluorite deposits(occurrences) have been found in this region. They are mainly classified into two types,including independent and associated fluorite deposits. The associated fluorite deposits are related to the low temperature Au and Sb deposits which are important components of the large-scale low-temperature metallogenic domain in South China. Until now, the weakness of researches on independent fluorite deposits has seriously restricted the understanding of ore genesis of this scarce strategic non-metallic mineral resource. The Gaoling fluorite deposit is a newly discovered independent one with associated minor Sb mineralization in the periphery of Qinglong Sb deposit. It is an ideal object for studying the ore genesis of independent fluorite deposit. Based on the detailed study of its deposit geology, the fluorite particle micro-drilling sampling technique and fluorite microwave digestion method were used to deal with fluorite samples for analyzing Pb and Sr isotopes by using the high-precision MC-ICPMS. The results show that the Pb isotopic ratios of fluorite are changed in relatively large ranges varying from 18.5107 to 20.1915 for ~(206)Pb/~(204)Pb, from 15.7075 to 15.8298 for ~(207)Pb/~(204)Pb, and from 36.6625 to 38.6938 for ~(208)Pb/~(204)Pb, respectively. The fluorites contain obviously enriched radiogenic Pb, suggesting that the source was rich in radiogenic Pb or the ore-forming fluids flowed through the radiogenic Pb-rich source region. However, the Sr isotopic ratios(~(87)Sr/~(86)Sr) of fluorites vary in a narrow range from 0.707845 to 0.707968, which is slightly higher than those of the ore-bearing limestone of Permian Maokou Formation(~(87)Sr/~(86)Sr =0.70679-0.70682), the Emeishan basalts(~(87)Sr/~(86)Sr =0.70480-0.70647), and the Permian seawater(~(87)Sr/~(86)Sr=0.70684-0.70820), indicating that the ore-forming fluids are relatively enriched in the radiogenic Sr. Furthermore, this suggests that the enriched radiogenic Sr could be brought by the ore-forming materials/fluids derived directly from the radiogenic Sr-rich source or obtained through interaction of the passing fluids and radiogenic Sr-rich geological body on the way of uplifting process. On the basis of comparison, this paper considers that the ore-forming materials/fluid of the Gaoling fluorite deposit have multi-source characteristics. The Gaoling deposit belongs to a same metallogenic system of the Qinglong Sb deposit and is a late-stage product of the large-scale low-temperature mineralization.
The southwestern Guizhou is one of the relatively concentrated areas of fluorite resources in Guizhou Province.At present, many fluorite deposits(occurrences) have been found in this region. They are mainly classified into two types,including independent and associated fluorite deposits. The associated fluorite deposits are related to the low temperature Au and Sb deposits which are important components of the large-scale low-temperature metallogenic domain in South China. Until now, the weakness of researches on independent fluorite deposits has seriously restricted the understanding of ore genesis of this scarce strategic non-metallic mineral resource. The Gaoling fluorite deposit is a newly discovered independent one with associated minor Sb mineralization in the periphery of Qinglong Sb deposit. It is an ideal object for studying the ore genesis of independent fluorite deposit. Based on the detailed study of its deposit geology, the fluorite particle micro-drilling sampling technique and fluorite microwave digestion method were used to deal with fluorite samples for analyzing Pb and Sr isotopes by using the high-precision MC-ICPMS. The results show that the Pb isotopic ratios of fluorite are changed in relatively large ranges varying from 18.5107 to 20.1915 for ~(206)Pb/~(204)Pb, from 15.7075 to 15.8298 for ~(207)Pb/~(204)Pb, and from 36.6625 to 38.6938 for ~(208)Pb/~(204)Pb, respectively. The fluorites contain obviously enriched radiogenic Pb, suggesting that the source was rich in radiogenic Pb or the ore-forming fluids flowed through the radiogenic Pb-rich source region. However, the Sr isotopic ratios(~(87)Sr/~(86)Sr) of fluorites vary in a narrow range from 0.707845 to 0.707968, which is slightly higher than those of the ore-bearing limestone of Permian Maokou Formation(~(87)Sr/~(86)Sr =0.70679-0.70682), the Emeishan basalts(~(87)Sr/~(86)Sr =0.70480-0.70647), and the Permian seawater(~(87)Sr/~(86)Sr=0.70684-0.70820), indicating that the ore-forming fluids are relatively enriched in the radiogenic Sr. Furthermore, this suggests that the enriched radiogenic Sr could be brought by the ore-forming materials/fluids derived directly from the radiogenic Sr-rich source or obtained through interaction of the passing fluids and radiogenic Sr-rich geological body on the way of uplifting process. On the basis of comparison, this paper considers that the ore-forming materials/fluid of the Gaoling fluorite deposit have multi-source characteristics. The Gaoling deposit belongs to a same metallogenic system of the Qinglong Sb deposit and is a late-stage product of the large-scale low-temperature mineralization.
引文
[1]李晖.我国萤石矿开发利用前景及战略选区资源潜力评价研究[D].北京:中国地质大学(北京),2010.
[2]王吉平,商朋强,熊先孝,等.中国萤石矿床成矿规律[J].中国地质,2015,42(1):18-32.
[3]王吉平,商朋强,熊先孝,等.中国萤石矿床分类[J].中国地质,2014,41(2):315-325.
[4]代德荣,何小虎,金少荣,等.黔西南萤石矿床流体包裹体地球化学特征[J].矿物学报,2018,38(6):693-700.
[5]金少荣,陈军,代德荣,等.黔西南高岭萤石矿床微量和稀土元素地球化学特征[J].矿物学报,2018,38(6):684-692.
[6]彭建堂,胡瑞忠,蒋国豪.萤石Sm-Nd同位素体系对晴隆锑矿床成矿时代和物源的制约[J].岩石学报,2003,19(4):785-791.
[7]Chen J,Yang RD,Du LJ,et al.Mineralogy,geochemistry and fluid inclusions of the Qingling Sb-(Au)deposit,Youjiang basin(Guizhou,SW China)[J].Ore Geology Reviews,2018,92:1-18.
[8]贵州省地质调查院.贵州省萤石矿矿产资源潜力评价报告[R].2012.
[9]刘建中,夏勇,邓一明,等.贵州水银洞Sbt研究及区域找矿意义探讨[J].黄金科学技术,2009,17(3):1-5.
[10]刘建中,夏勇,陶琰,等.贵州西南部SBT与金锑矿成矿找矿[J].贵州地质,2014,31(4):267-272.
[11]彭建堂,胡瑞忠,蒋国豪.贵州晴隆锑矿床中萤石的Sr同位素地球化学[J].高校地质学报,2003,9(2):244-251.
[12]陈军.贵州晴隆大厂锑矿床锑(金)成矿作用研究[D].贵州大学:博士学位论文.
[13]Zartman RE,Doe BR.Plumbotectonics-the model[J].Tectonophysics,1981,75(1-2):135-162.
[14]周家喜,黄智龙,周国富,等.黔西北赫章天桥铅锌矿床成矿物质来源:S、Pb同位素和REE制约[J].地质论评,2010,56(4):513-524.
[15]Zhou JX,Xiang ZZ,Zhou MF,et al.The giant Upper Yangtze Pb-Zn province in SW China:Reviews,new advances and a new genetic model[J].Journal of Asian Earth Sciences,2018,154:280-315.
[16]金中国,周家喜,黄智龙,等.贵州普定纳雍枝铅锌矿矿床成因:S和原位Pb同位素证据[J].岩石学报,2016,32(11):3441-3455.
[17]崔银亮,周家喜,黄智龙,等.云南富乐铅锌矿床地质,地球化学及成因[J].岩石学报,2018,34(1):194-206.
[18]Faure G.Principles of Isot ope Geology[M].New York:John Wiley Sons,1977,97-146.
[19]Zhou J,Huang Z,Zhou M,et al.Constraints of C-O-S-Pb isotope compositions and Rb-Sr isotopic age on the origin of the Tianqiao carbonate-hosted Pb-Zn deposit,SW China[J].Ore Geology Reviews,2013,53:77-92.
[20]彭建堂,胡瑞忠,漆亮,等.晴隆锑矿床中萤石的稀土元素特征及其指示意义[J].地质科学,2002,37(3):277-287.
[21]王国芝,胡瑞忠,刘颖,等.黔西南晴隆锑矿区萤石的稀土元素地球化学特征[J].矿物岩石,2003,23(2):62-65.
[22]苏文超,朱路艳,格西,等.贵州晴隆大厂锑矿床辉锑矿中流体包裹体的红外显微测温学研究[J].岩石学报,2015,31(4):918-924.
[2]王吉平,商朋强,熊先孝,等.中国萤石矿床成矿规律[J].中国地质,2015,42(1):18-32.
[3]王吉平,商朋强,熊先孝,等.中国萤石矿床分类[J].中国地质,2014,41(2):315-325.
[4]代德荣,何小虎,金少荣,等.黔西南萤石矿床流体包裹体地球化学特征[J].矿物学报,2018,38(6):693-700.
[5]金少荣,陈军,代德荣,等.黔西南高岭萤石矿床微量和稀土元素地球化学特征[J].矿物学报,2018,38(6):684-692.
[6]彭建堂,胡瑞忠,蒋国豪.萤石Sm-Nd同位素体系对晴隆锑矿床成矿时代和物源的制约[J].岩石学报,2003,19(4):785-791.
[7]Chen J,Yang RD,Du LJ,et al.Mineralogy,geochemistry and fluid inclusions of the Qingling Sb-(Au)deposit,Youjiang basin(Guizhou,SW China)[J].Ore Geology Reviews,2018,92:1-18.
[8]贵州省地质调查院.贵州省萤石矿矿产资源潜力评价报告[R].2012.
[9]刘建中,夏勇,邓一明,等.贵州水银洞Sbt研究及区域找矿意义探讨[J].黄金科学技术,2009,17(3):1-5.
[10]刘建中,夏勇,陶琰,等.贵州西南部SBT与金锑矿成矿找矿[J].贵州地质,2014,31(4):267-272.
[11]彭建堂,胡瑞忠,蒋国豪.贵州晴隆锑矿床中萤石的Sr同位素地球化学[J].高校地质学报,2003,9(2):244-251.
[12]陈军.贵州晴隆大厂锑矿床锑(金)成矿作用研究[D].贵州大学:博士学位论文.
[13]Zartman RE,Doe BR.Plumbotectonics-the model[J].Tectonophysics,1981,75(1-2):135-162.
[14]周家喜,黄智龙,周国富,等.黔西北赫章天桥铅锌矿床成矿物质来源:S、Pb同位素和REE制约[J].地质论评,2010,56(4):513-524.
[15]Zhou JX,Xiang ZZ,Zhou MF,et al.The giant Upper Yangtze Pb-Zn province in SW China:Reviews,new advances and a new genetic model[J].Journal of Asian Earth Sciences,2018,154:280-315.
[16]金中国,周家喜,黄智龙,等.贵州普定纳雍枝铅锌矿矿床成因:S和原位Pb同位素证据[J].岩石学报,2016,32(11):3441-3455.
[17]崔银亮,周家喜,黄智龙,等.云南富乐铅锌矿床地质,地球化学及成因[J].岩石学报,2018,34(1):194-206.
[18]Faure G.Principles of Isot ope Geology[M].New York:John Wiley Sons,1977,97-146.
[19]Zhou J,Huang Z,Zhou M,et al.Constraints of C-O-S-Pb isotope compositions and Rb-Sr isotopic age on the origin of the Tianqiao carbonate-hosted Pb-Zn deposit,SW China[J].Ore Geology Reviews,2013,53:77-92.
[20]彭建堂,胡瑞忠,漆亮,等.晴隆锑矿床中萤石的稀土元素特征及其指示意义[J].地质科学,2002,37(3):277-287.
[21]王国芝,胡瑞忠,刘颖,等.黔西南晴隆锑矿区萤石的稀土元素地球化学特征[J].矿物岩石,2003,23(2):62-65.
[22]苏文超,朱路艳,格西,等.贵州晴隆大厂锑矿床辉锑矿中流体包裹体的红外显微测温学研究[J].岩石学报,2015,31(4):918-924.