The evolution of ore-forming fluid and its constrain to the ore-forming process in Limu Ta-Nb-Sn polymetallic ore deposit, Guangxi, China
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摘要: 广西栗木钽铌锡多金属矿床既产具明显垂直分带的花岗岩型钽铌锡矿体,又有石英脉型钨锡矿体,是研究岩浆-热液演化过程的典型实例.本次研究对栗木矿区中水溪庙和金竹源两个矿床开展了系统成矿流体研究.研究表明栗木矿区中的包裹体类型主要有盐水溶液包裹体、H2O-CO2-NaCl包裹体和熔体包裹体三类.自云英岩化钠长石花岗岩→似伟晶岩→长石石英脉型→锂云母萤石脉,盐水溶液包裹体逐渐由定向分布的次生包裹体特征,转变为面状孤立分布的原生包裹体特征,而且均一温度、盐度和密度逐渐降低,具有低均一温度(150~210℃)、低盐度(1.0%~9.0% NaCleqv)和低密度(0.83~1.05g/cm3)的特点.H2O-CO2-NaCl包裹体和熔体包裹体主要产在钠长石花岗岩和似伟晶岩中,H2O-CO2-NaCl包裹体孤立分布,均一温度为260~350℃,盐度为0.8%~8.5% NaCleqv;熔体包裹体的固相初熔温度为560~600℃,完全均一温度为704~853℃,流体相具有与盐水溶液包裹体相近的均一温度和盐度.根据以上资料,本文把栗木矿区的成矿作用分为岩浆阶段的钽铌锡成矿作用和岩浆热液阶段的钨锡成矿作用,估算成岩成矿压力约为270MPa,这有利于栗木矿区的钽铌锡在花岗岩浆阶段发生了相对贫化的富集作用,钽、铌、锡、钨等元素在熔体/流体的分配系数制约了钽铌成矿作用发生在岩浆阶段,而钨锡成矿作用主要发生在热液阶段.Abstract: Limu Ta-Nb-Sn polymetallic deposit in Guangxi, China, composed of granite type Ta-Nb-Sn ore body with vertical mineralization zoning, and quartz vein type W-Sn ore body, is a typical case for us to research the melt-fluid evolution at magmatic to hydrothermal transition. In this paper, we analyzed the ore-forming fluid features of Shuiximiao deposit and Jinzhuyuan deposit in Limu ore area systematically. The experimental results showed that brine fluid inclusions, H2O-CO2-NaCl fluid inclusions and melt inclusions were hosted in quartz in Limu ore area. From greisenization albite granite, stockscheider, feldspar quartz vein, to lithum mica fluorite vein in turn, brine fluid inclusions exist with the feature changing from secondary origin of directional distribution to primary origin with isolated distribution. The results of microthermometric analyses for brine fluid inclusions showed a low homogenization temperature (150~210℃), a low salinity (1.0%~9.0% NaCleqv.) and a low density (0.83~1.05g/cm3), which all decreased gradually from the lower to upper mineralization zone. H2O-CO2-NaCl fluid inclusions and melt inclusions were mainly hosted in albite granite and stockscheider. H2O-CO2-NaCl fluid inclusions usually distribute in isolation with the homogenization temperature of 260~350℃ and salinities of 0.8%~8.5% NaCleqv. The initial melting temperatures and completely homogenization temperatures of melt inclusions were 560~600℃ and 704~853℃ respectively, and the fluid phase within melt inclusions have similar homogenization temperature and salinity with that of brine fluid inclusions. Based on the experimental results, the mineralization of Limu ore area can be divided into two stages, one is the mineralization of Ta, Nb and Sn in the magmatic stage, and the other is the mineralization of W and Sn in the magmatic hydrothermal stage. We estimated the ore-forming pressure was about 270MPa, which benefit the enrichment of Ta, Nb and Sn in the granitic magma stage. The different distribution coefficient of Ta, Nb, W and Sn between melt and fluid phases is an important factor controlling the mineralization of Ta and Nb in the magmatic stage, and the mineralization of W and Sn in the hydrothermal stage.
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Key words:
- Ore-forming fluid /
- Rare metal /
- Granite /
- Melt inclusion /
- Hydrothermal diamond-anvil cell
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[1] Anderson AJ, Meredith PR, Bassett WA et al. 2010. The design and application of a new Bassett-type diamond anvil cell for spectroscopic analysis of supercritical aqueous solutions. Proceedings of the CNS 2nd Canada-China Joint Workshop on SuperCritical Water-Cooled Reactors (SCWR), 2010
[2] Bassett WA, Shen AH, Bucknum M et al. 1993. A new diamond anvil cell for hydrothermal studies to 2.5GPa and from -190 to 1200℃. Rev. Sci. Instrum., 64: 2340-2345
[3] Chou IM. 2001. Hydrothermal diamond-anvil cell: Application to studies of geologic fluids. Acta Petrologica Sinica, 19(2): 213-220
[4] Darling RS and Bassett W. 2002. Analysis of natural H2O+CO2+NaCl fluid inclusions in the hydrothermal diamond anvil cell. American Mineralogist, 87: 69-78
[5] Department of Geology, Nanjing University. 1981. Granites of Different Ages in South China and Their Metallogenetic Relations. Beijing: Science Press, 1-408 (in Chinese)
[6] Gan XC, Zhu JC and Shen WZ. 1992. The genesis of Shuiximiao rare metal granite Limu, Guangxi Autonomous Region. Contributions to Geology and Mineral Resources Research, 7(2): 35-45 (in Chinese with English abstract)
[7] Guo CJ. 1959. Geochemical Characteristics of Some Rare Metal Elements in the Early Processes of Magmatism. Beijing: Science Press, 1-138 (in Chinese)
[8] Gysi AP and Williams-Jones AE. 2012. Fluid-rock interaction in the Strange Lake peralkaline granite pluton, Canada: Implication for REE/HFSE mobility. Goldschmidt 2012 Conference Abstracts
[9] Наумов В. В. идр. 1971. Генезис Топазов по данным изучения микровкючений Геохимия N. 3
[10] Hu XY, Bi XW, Hu RZ et al. 2007. Advances in tin distribution between granitic melts and coexisting aqueous fluids and a review of tin in fluids and melts. Advances in Earth Science, 22(3): 61-69 (in Chinese with English abstract)
[11] Keppler H. 1993. Influence of fluorine on the enrichment of high field strength trace elements in granitic rocks. Contributions to Mineralogy and Petrology, 114(4): 479-488
[12] Li FC, Zhu JC, Rao B et al. 2000a. New evidence for magmatic genesis of fluorite in the F-rich granite. Acta Mineralogica Sinica, 20(3): 224-227 (in Chinese with English abstract)
[13] Li FC, Zhu JC, Jin ZD et al. 2000b. Formation mechanism of snowball texture in albite granite. Acta Petrologica et Mineralogica, 19(1): 27-35 (in Chinese with English abstract)
[14] Li FC, Zhu JC and Jin ZD. 2000c. Genetic interpretation of Li-F rich rare metal-bearing granites in South China. Mineral Deposits, 19(4): 376-385 (in Chinese with English abstract)
[15] Li JK, Zhang DH, Wang DH et al. 2008. Liquid immiscibility of fluorine-rich granite magma and its diagenesis and metallogeny. Geological Review, 54(2): 175-183 (in Chinese with English abstract)
[16] Li JK, Yuan ZX, Bai G et al. 2009. Ore-forming fluid evolvement and its controlling to REE (AG) mineralizing in the Weishan deposit, Shandong. Journal of Mineralogy and Petrology, 29(3): 60-68 (in Chinese with English abstract)
[17] Li JK, Zhang DH and Li SH. 2011. Application of melt inclusions to estimating ore-forming pressure (depth) of granite-related ore deposits. Mineral Deposits, 30(6): 1002-1016 (in Chinese with English abstract)
[18] Li JK, Wang DH and Chen YC. 2012. The ore-forming mechanism of the Jiajika pegmatite-type rare metal deposit in western Sichuan Province: Evidence from isotope dating. Acta Geologica Sinica, 87(1): 801-840
[19] Li JK, Chou IM, Yuan SD and Burruss RC. 2013. Observations on the crystallization of spodumene from aqueous solutions in a hydrothermal diamond-anvil cell. Geofluids, 13(4): 467-474
[20] Lin DS and Wang KX. 1986. Study on surface indication zone of granite type Sn-Ta-Nb deposit (take Limu ore area for an example). Mineral Resources and Geology, (1): 10-18 (in Chinese)
[21] Lin DS. 1993. Comparison study of the 414 ore deposit with Limu orefield. Mineral Resources and Geology, 36(7): 262-266 (in Chinese with English abstract)
[22] Lin DS. 1996. Tantalum-rich Type Granite Deposits in South China. Beijing: Geological Publishing House, 1-147 (in Chinese)
[23] London D. 1984. Experimental phase equilibria in the system LiAlSiO4-SiO2-H2O: A petrogeneticgrid for lithium-rich pegmatites. American Minerallogist, 69: 995-1004
[24] Mo ZS. 1980. The Geology of Nanling Granite. Beijing: Geological Publishing House, 1-126 (in Chinese)
[25] Roedder E and Bodnar RJ. 1980. Geologic pressure determinations from fluid inclusion studies. Annual Review of Earth and Planetary Sciences, 8: 263-301
[26] Samson IM and Williams-Jones AE. 2012. The role of fluids in the formation of REE (-Zr, Nb, Ta) deposits associated with alkaline plutons. Goldschmidt 2012 Conference Abstracts
[27] Schmidt C, Chou IM, Bodnar RJ et al. 1998. Microthermometric analysis of synthetic fluid inclusions in the hydrothermal diamond-anvil cell. American Mineralogist, 83: 995-1007
[28] Shcherba GN. 1970. Greisens. International Geology Review, 12(2): 114-150
[29] Student JJ and Bodnar RJ. 1999. Synthetic fluid inclusions XIV: Coexisting silicate melt and aqueous fluid inclusions in the haplogranite-H2O-NaCl-KCl system. Journal of Petrology, 40(10): 1509-1525
[30] Veksler IV. 2004. Liquid immiscibility and its role at the magmatic-hydrothermal transition: A summary of experimental studies. Chemical Geology, 210(1-4): 7-31
[31] Yuan ZX, Bai G and Yang YQ. 1987. A discussion on petrogenesis of rare metal granites. Mineral Deposits, 6(1): 84-96 (in Chinese with English abstract)
[32] Zhang DH and Gong QJ. 2001. On the geochemical mechanisms of enrichment and ore formation of ore metals. Geology-Geochemistry, 29(3): 8-14 (in Chinese with English abstract)
[33] Zhang JT. 1989. Ta-Nb-W-Sn deposit Limu, Guangxi Autonomous Region. In: Chen YC, Pei RF and Zhang HL (eds.). The Geology of Nonferrous and Rare Metal Ore Deposit Related to Mesozoic Granite in Nanling Region. Beijing: Geological Publishing House, 130-140 (in Chinese)
[34] Zhao JS, Zhao B and Rao B. 1996a. A preliminary experimental study on mineralization of Nb, Ta and W. Geochimica, 25(3): 286-295 (in Chinese with English abstract)
[35] Zhao JS, Zhao B and Rao B. 1996b. A preliminaty experimental study on the distribution behavior of Ta, Nb and W in albite granite magma during its crystallization and differentiation. Chinese Science Bulletin, 41(15): 1413-1417 (in Chinese)
[36] Zhou FY, Zhu JC, Wang RC et al. 1995. A study on the genesis of Shuiximiao granitic pegmatite dikes. Journal of Nanjing University (Natural Sciences), 31(4): 641-648 (in Chinese with English abstract)
[37] Zhu JC, Li RK, Zhou FY et al. 1996. Genesis of asymmetrically layered pegmatiteaplite dykes of Shuiximiao mine, Limu district, Guangxi. Geochimica, 25(1): 1-9 (in Chinese with English abstract)
[38] Zhu JC, Rao B, Xiong XL et al. 2002. Comparison and genetic interpretation of Li-F rich, rare-metal bearing granitic rocks. Geochimica, 31(2): 141-152 (in Chinese with English abstract)
[39] 甘晓春, 朱金初, 沈渭洲. 1992. 广西栗木水溪庙稀有金属花岗岩成因. 地质找矿论丛, 7(2): 35-45
[40] 郭承基. 1959. 早期岩浆作用过程中某些稀有元素的地球化学特征. 北京: 科学出版社, 1-138
[41] 胡晓燕, 毕献武, 胡瑞忠等. 2007. 锡在花岗质熔体和流体中的性质及分配行为研究进展. 地球科学进展, 22(3): 61-69
[42] 李福春, 朱金初, 饶冰等. 2000a. 富氟花岗岩中萤石岩浆成因的新证据. 矿物学报, 20(3): 224-227
[43] 李福春, 朱金初, 金章东等. 2000b. 钠长石花岗岩中雪球结构形成机理的研究. 岩石矿物学杂志, 19(1): 27-35
[44] 李福春, 朱金初, 金章东. 2000c. 华南富锂氟含稀有金属花岗岩的成因分析. 矿床地质, 19(4): 376-385
[45] 李建康, 张德会, 王登红等. 2008. 富氟花岗岩浆液态不混溶作用及其成岩成矿效应. 地质论评, 54(2): 175-183
[46] 李建康, 袁忠信, 白鸽等. 2009. 山东微山稀土矿床成矿流体的演化及对成矿的制约. 矿物岩石, 29(3): 60-68
[47] 李建康, 张德会, 李胜虎. 2011. 熔体包裹体在估算花岗岩类矿床形成压力(深度)方面的应用. 矿床地质, 30(6): 1002-1016
[48] 林德松, 王开选. 1986. 花岗岩型锡钽铌矿床地表标志带研究(以栗木矿田为例). 矿产与地质, (1): 10-18
[49] 林德松. 1993. 414矿床和栗木矿田的对比特征研究. 矿产与地质, 36(7): 262-266
[50] 林德松. 1996. 华南富钽花岗岩矿床. 北京: 地质出版社, 1-147
[51] 莫柱孙. 1980. 南岭花岗岩地质学. 北京: 地质出版社, 1-363
[52] 南京大学地质系. 1981. 华南不同时代花岗岩类及其与成矿关系. 北京: 科学出版社, 1-408
[53] 袁中信, 白鸽, 杨岳清. 1987. 稀有金属花岗岩型矿床成因讨论. 矿床地质, 6(1): 88-96
[54] 张德会, 龚庆杰. 2001. 初论元素富集成矿的地球化学机理——以岩浆热液矿床的形成为例. 地质地球化学, 29(3): 8-14
[55] 章锦统. 1989. 广西栗木铌、钽、钨、锡矿床. 见: 陈毓川, 裴荣富, 张宏良编. 南岭地区与中生代花岗岩类有关的有色及稀有金属矿床地质. 北京: 地质出版社, 130-140
[56] 赵劲松, 赵斌, 饶冰. 1996a. 初论铌、钽和钨的成矿作用: 实验研究. 地球化学, 25(3): 286-295
[57] 赵劲松, 赵斌, 饶冰. 1996b. Ta, Nb, W在钠长花岗岩岩浆结晶分异过程中于各相间分配行为的实验研究. 科学通报, 41(15): 1413-1417
[58] 周凤英, 朱金初, 王汝成等. 1995. 水溪庙花岗伟晶岩脉的成因研究. 南京大学学报, 31(4): 641-648
[59] 朱金初, 李人科, 周凤英等. 1996. 广西栗木水溪庙不对称层状伟晶岩-细晶岩岩脉的成因讨论. 地球化学, 25(1): 1-9
[60] 朱金初, 饶冰, 熊小林等. 2002. 富锂氟含稀有矿化花岗质岩石的对比和成因思考. 地球化学, 31(2): 141-152
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