四川平武钨锡铍矿床成矿流体特征
摘要
四川平武新近发现多处规模较大的产于晶洞中的绿柱石、锡石和白钨矿宝石矿。本文对矿石矿物绿柱石、锡石和白钨矿中的流体包裹体进行了分析,直接获取了成矿期的流体信息,由于绿柱石、锡石的结晶均较早,故更为接近原始成矿流体的性质。平武钨锡铍宝石矿中流体包裹体有气液两相包裹体、CO2三相包裹体和含子矿物包裹体三种类型。包裹体完全均一温度最佳取值区间为260~300℃,盐度范围为0.53%~8.73%NaCleq,压力估算小于10.5MPa,矿床类型属于浅成中低温热液型。绿柱石中含子矿物包裹体和CO2三相包裹体共存,二者均一温度平均值较为相近,显示了不混溶流体包裹体的特征。绿柱石包裹体的完全均一温度和盐度平均值均高于白钨矿和锡石,绿柱石和白钨矿包裹体液相成分中F-、Cl-离子含量高于锡石。绿柱石、白钨矿和锡石三种矿物沉淀的先后顺序为:绿柱石锡石白钨矿。
Pingwu,the important beryl,scheelite and cassiterite producer in China,locates at south margin of the South China craton.Fluid inclusion studies show that ore-forming fluids of W—Sn—Be deposit in this area are consistent with three different types,and the fluids are characterized by liquid CO2-rich fluid(type Ⅰ),3-phase H2O—CO2 inclusions(type Ⅱ)and fluid inclusions containing daughter minerals(type Ⅲ).The homogenization temperatures of types Ⅰ and Ⅲ inclusions coexisting in beryl are very closely which shows fluid immiscibility.The salinity of inclusions ranges from 0.53% to 4.67 % NaCleq and pressure of ore-forming is <10.5MPa,which reflects the minerlization occurred in upper crust.The density and temperature of fluid is very low,which indicates that the beryl daughter minerals formed before saturation of ore-forming fluid and then captured by fluid.
Pingwu,the important beryl,scheelite and cassiterite producer in China,locates at south margin of the South China craton.Fluid inclusion studies show that ore-forming fluids of W—Sn—Be deposit in this area are consistent with three different types,and the fluids are characterized by liquid CO2-rich fluid(type Ⅰ),3-phase H2O—CO2 inclusions(type Ⅱ)and fluid inclusions containing daughter minerals(type Ⅲ).The homogenization temperatures of types Ⅰ and Ⅲ inclusions coexisting in beryl are very closely which shows fluid immiscibility.The salinity of inclusions ranges from 0.53% to 4.67 % NaCleq and pressure of ore-forming is <10.5MPa,which reflects the minerlization occurred in upper crust.The density and temperature of fluid is very low,which indicates that the beryl daughter minerals formed before saturation of ore-forming fluid and then captured by fluid.
引文
邓军,高帮飞,王庆飞,杨立强.2005.成矿流体系统的形成与演化.地质科技情报,24(1):49~54.
丁俊英,倪培,饶冰,周进,朱筱婷.2004.显微激光拉曼光谱测定单个包裹体盐度的实验研究.地质论评,50(2):203~209.
刘斌,沈昆.1999.流体包裹体热力学.北京:地质出版社,44~72.
卢焕章,范宏瑞,倪培,欧光习,沈昆,张文淮.2004.流体包裹体.北京:科学出版社,21~33,180~224.
杨立强,邓军,翟裕生.2000.构造—流体—成矿系统及其动力学.地学前缘,7(1):178.
张静,陈衍景,舒桂明,张复新,李超.2002.陕西西南部秦岭梁花岗岩体的矿物成分研究和相关问题讨论.中国科学(D辑),32(2):113~119.
章雨旭.2006.地质学研究中常见逻辑方面的问题分析.高校地质学报,12(1):147~152.
Barnes H L.1979.Geochemistry of Hydrothermal Ore Deposits.New York:John Wiley&Sons,186:404~460.
Cao Zhimin,Li Youguo,Ren Jianguo,Li Baohua,Xu Shijin,WangRucheng,Shoji T,Kaneda H,Kabayashi S.2002.Geologicand geochemical features of the volatile-rich ore fluid and itstracing and dating in the Xuebaoding beryl—scheelite veindeposit,China.Science in China(Series D),45(8):719~729.
Fan Hongrui,Zhai Mingguo,Xie Yihan,Yang Jinhui.2003.Ore-forming fluids associated with granite-hosted gold mineralizationat the Sanshandao deposit,Jiaodong gold province,China.Mineralium Deposita,38:739~750.
Keppler H,Wyllie P J.1991.Partitioning of Cu,Sn,Mo,W,Uand Th between melt and aqueous fluid in the systemshaplogranite—H2O—HCl and haplogranite—H2O—HF.Contrib.Mineral.Petrol.,109:139~150.
Schwartz M O.1989.Determining phase volumes of mixed CO2—H2O inclusions using microthermometric measurements.Mineralium Deposita,24:43~47.
Vallance J,Cathelineau M,Marignac C,Boiron M C,Fourcade S,Martineau F,Fabre C.2001.Microfracturing and fluid mixingin granites:W—(Sn)ore deposition at Vaulry(NW FrenchMassif Central).Tectonophysics,336:43~61.
Wilkinson J J.2001.Fluidinclusions in hydrothermal ore deposits.Lithos,55:229~272.
Zhu Heping,Wang Lijuan.2002.Determining gaseous compositionof fluid inclusions with quadrupole mass spectrometer.Sciencein China(Ser.D),45(2):97~102.
丁俊英,倪培,饶冰,周进,朱筱婷.2004.显微激光拉曼光谱测定单个包裹体盐度的实验研究.地质论评,50(2):203~209.
刘斌,沈昆.1999.流体包裹体热力学.北京:地质出版社,44~72.
卢焕章,范宏瑞,倪培,欧光习,沈昆,张文淮.2004.流体包裹体.北京:科学出版社,21~33,180~224.
杨立强,邓军,翟裕生.2000.构造—流体—成矿系统及其动力学.地学前缘,7(1):178.
张静,陈衍景,舒桂明,张复新,李超.2002.陕西西南部秦岭梁花岗岩体的矿物成分研究和相关问题讨论.中国科学(D辑),32(2):113~119.
章雨旭.2006.地质学研究中常见逻辑方面的问题分析.高校地质学报,12(1):147~152.
Barnes H L.1979.Geochemistry of Hydrothermal Ore Deposits.New York:John Wiley&Sons,186:404~460.
Cao Zhimin,Li Youguo,Ren Jianguo,Li Baohua,Xu Shijin,WangRucheng,Shoji T,Kaneda H,Kabayashi S.2002.Geologicand geochemical features of the volatile-rich ore fluid and itstracing and dating in the Xuebaoding beryl—scheelite veindeposit,China.Science in China(Series D),45(8):719~729.
Fan Hongrui,Zhai Mingguo,Xie Yihan,Yang Jinhui.2003.Ore-forming fluids associated with granite-hosted gold mineralizationat the Sanshandao deposit,Jiaodong gold province,China.Mineralium Deposita,38:739~750.
Keppler H,Wyllie P J.1991.Partitioning of Cu,Sn,Mo,W,Uand Th between melt and aqueous fluid in the systemshaplogranite—H2O—HCl and haplogranite—H2O—HF.Contrib.Mineral.Petrol.,109:139~150.
Schwartz M O.1989.Determining phase volumes of mixed CO2—H2O inclusions using microthermometric measurements.Mineralium Deposita,24:43~47.
Vallance J,Cathelineau M,Marignac C,Boiron M C,Fourcade S,Martineau F,Fabre C.2001.Microfracturing and fluid mixingin granites:W—(Sn)ore deposition at Vaulry(NW FrenchMassif Central).Tectonophysics,336:43~61.
Wilkinson J J.2001.Fluidinclusions in hydrothermal ore deposits.Lithos,55:229~272.
Zhu Heping,Wang Lijuan.2002.Determining gaseous compositionof fluid inclusions with quadrupole mass spectrometer.Sciencein China(Ser.D),45(2):97~102.
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