地球科学进展 ›› 2012, Vol. 27 ›› Issue (10): 1061 -1067. doi: 10.11867/j.issn.1001-8166.2012.10.1061
矿床地球化学与成矿成因 上一篇 下一篇
收稿日期:
修回日期:
出版日期:
通讯作者:
基金资助:
国家自然科学基金项目“若尔盖地区碳硅泥岩型铀矿床垂直分带规律研究”（编号：41072064）资助.
Chen Youliang 1，Wei Jia 1，Ye Yongqin 1，Song Hao 1，Sun Zexuan 2
Received:
Revised:
Online:
Published:
方解石是若尔盖铀矿田与成矿最为密切的脉石矿物之一。方解石的REE地球化学特征研究表明，产于地层中的方解石、矿区中的方解石和含矿方解石具有明显不同的稀土元素组成特征，分别具有轻稀土富集右倾型、重稀土富集左倾型和相对平坦型的3种稀土配分模式。其中产于地层中的方解石明显继承了地层中岩石的稀土元素特征，而含矿方解石表现出与矿石稀土元素相似的特征。碳氧同位素显示地层中的方解石为海洋沉积碳酸盐岩的碳氧同位素组成特征；矿区方解石脉、含矿方解石脉的碳同位素组成明显表现为地幔来源的特点；而矿区方解石脉的氧同位素组成具明显的深部来源特征，含矿方解石脉的氧同位素组成表明在成矿过程中有大气降水的混入。若尔盖铀矿田的方解石主要为热液成因，其矿床成因类型属于典型的热液矿床，成矿流体主要来源于地幔。
Calcite is one of the main gangue minerals in the Zoige Uranium Ore Field, which has a most close relation with uranium mineralization. Based on analyzing geochemistry characteristics of REE of calcite in strata, calcite in the mine area and ore-bearing calcite, their REE model is characterized by enrichment in light REE (decline to right), heavy REE (decline to left) and relatively flat of REE distribution patterns, respectively. Among them, calcite in strata shows the characteristics of the obvious inheritance of the sedimentary rocks, while the characteristics of rare earth elements of the ore-bearing calcite are similar to those of the ore-stone. Carbonoxygen isotopic characteristics of calcite in strata shows the carbon-oxygen compositions of marine carbonate rocks, while the other two implying an involvement of mantle derived source. Oxygen isotopic characteristics suggests existence of deeply-derived fluid for the calcite in the mine area, while oxygen isotopic characteristics of ore-bearing calcite show the evident addition of some introduced fluids possibly from infiltrating atmospheric water into the ore-forming fluids. Calcite in Zoige Uranium Ore Field is mainly of hydrothermal origin, and the type of the genesis is a typical hydrothermal deposit with its ore forming fluid originated from mantle.
中图分类号:
P595
P597
[1]Chen Youliang.Current status and prospecting vistas of uranium resources in southwest of China[J].Uranium Geology，2004，20(1)：1-3.[陈友良.西南地区铀资源现状与找矿前景展望[J].铀矿地质，2004，20(1)：1-3.][2]Chen Youliang，Hou Mingcai，Zhu Xiyang, et al. Petrology and genesis of ore-bearing rock series in the Zoige uranium orefield[J].Journal of Chengdu University of Technology (Science ＆ Technology Edition),2007,34(5):553-558.[陈友良，侯明才，朱西养,等.若尔盖铀矿田含矿岩系的岩石特征及成因探讨[J].成都理工大学学报:自然科学版，2007，34(5):553-558.][3]Chen Youliang.The Study on Ore-forming Fluid Genesis and Ore-forming Model of Carbonaceous-Siliceous-Argillitic Rock Type Uranium Deposit in Zoige Region[D].Chengdu: Chengdu University of Technology，2008.[陈友良.若尔盖地区碳硅泥岩型铀矿床成矿流体成因和成矿模式研究[D].成都：成都理工大学，2008.][4]Mao Yunian，Min Yongming.The Siliceous-Calcareous-Argillaceous Rock Type Uranium Deposit in Western Qinling[M].Beijing：Geologic Press，1989:71-104.[毛裕年，闵永明.西秦岭硅灰泥岩型铀矿[M].北京: 地质出版社，1989:71-104.][5]Wang Ju.Geochemistry of Ore-Forming Process of Carbonaceous-Siliceous-Argillaceous Rock-Hosted Gold（Uranium） Deposits in China[D].Beijing: Beijing Research Institute of Uranium Geology，1991.[王驹.碳硅泥岩型金（铀）矿床成矿富集的地球化学[D].北京：核工业北京地质研究院，1991.][6]He Mingyou.Tectonomagmatic Activation Genetic Model for Rouergai Uranium Metallogenic Zone[D].Chengdu:Chengdu Institute of Technology，1993.[何明友.若尔盖铀成矿带构造—岩浆活化成因模式[D].成都：成都理工学院，1993.][7]Zhao Bing.The stable isotope geochemistry of uranium deposits in Rouergai，western Qinling[J].Journal of Mineralogy and Petrology，2002，22（4）： 47-51.[赵兵.西秦岭若尔盖铀矿床稳定同位素地球化学特征[J].矿物岩石，2002，22（4）： 47-51.][8]Zhong S J，Alfonso M.Partitioning of Rare Earth Elements(REEs) between calcite and seawater solutions at 25 ℃ and 1 atm，and high dissolved REE concentrations[J].Geochimica et Cosmochimica Acta，1995，59：443-453.[9]Sun S S, McDonough W F. Chemical and isotopic systematics of oceanic basatts: Implication for mantle composition and process[C]∥Saunders A D, Norry M J, eds. Magmatism in the Ocean Basin. London: Geological Society Publishing House,1989:313-345.[10]Zhao Bing. The Study of Geochemistry and Genesis for Ruoergail Uranium Metallogenic Zone[D]. Chengdu: Chengdu Institute of Technology, 1994.[赵兵.若尔盖铀成矿带地球化学与矿床成因研究[D].成都：成都理工学院，1994.][11]Mller P，Morteani G.On the geochemical fractionation of rare earth elements during the formation of Ca-minerals and its application to problems of the genesis of ore deposits[C]∥Augusthitis S S ed. The Siginificance of Trace Elements in Solving Petrogenetic Problems and Controversies. Athens: Theophrastus, 1983:747-791.[12]He Mingyou，Jin Jingfu. A study on mineralizer-source in ore-forming fluid of the Rouergai uranium deposits[J].Computing techniques for Geophysical and Geochmical Exploration，1996，18(S1)：122-125.[何明友，金景福.若尔盖铀矿床成矿流体中矿化剂来源研究[J].物探化探计算技术，1996，18（增刊1）：122-125.][13]Huang Changhua，Zhang Chengjiang，Zhou Bing. Physical-chemical conditions of mineralization of No.510-1 hydrothermal-type uranium deposit of Ruergai Area，Sichuan Province[J].Acta Mineralogica Sinica，2012，32（3）： 398-402.[黄昌华，张成江，周兵.四川省若尔盖地区510-1热液型铀矿床形成的物理化学条件研究[J].矿物学报，2012，32（3）： 398-402.][14]Ohmoto H. Systematics of sulfur and carbon isotopes in hydrothermal ore deposits[J].Economic Geology，1972，67(5):551-578.[15]Faure G.Principles of Isotope Geology[M].New York:John Wiley, 1986.[16]Huang Shijie.Preliminary discussion on deep-sourced uranium metallogenesis and deep prospecting[J].Uranium Geology，2006，22(2)：70-75.[黄世杰.略谈深部铀成矿与深部找矿问题[J].铀矿地质,2006,22(2):70-75.]