江西冷水坑银-铅-锌矿床同位素地球化学研究  

A Study of the Isotope Geochemistry of the Lenshuikeng Ag-Pb-Zn Ore Deposit, Jiangxi Province

作　　者：徐文炘[1] 肖孟华[1] 陈民扬[1] 

机构地区：[1]桂林矿产地质研究院,广西桂林541004

出　　处：《矿物岩石地球化学通报》2001年第4期370-372,共3页Bulletin of Mineralogy, Petrology and Geochemistry

摘　　要：江西冷水坑银 铅 锌矿床是一个斑岩型矿床 ,花岗斑岩的Rb Sr同位素年龄为 131.0± 5 .1Ma ,初始锶同位素比值为 0 .7110 5± 0 .0 0 2 75 ;火山岩的Rb Sr同位素年龄为 10 1.3± 4.1Ma ,初始锶同位素比值为0 .7142 4± 0 .0 0 5 6 9。花岗斑岩和火山岩的K Ar同位素为 83～ 138Ma。从成矿早阶段到晚阶段 ,形成温度为30 0～ 2 5 0℃ ;logfO2 从 - 30 .12下降到 - 40 .78;logffCO2 从 2 .2 9下降到 0 .2 2 ;logfS2 为 - 9.94～ - 11.6 ;pH值为 3～4.8。从成矿Ⅱ1 到Ⅱ3 ,硫化物的δ3 4 S值为 - 4‰～ +5‰ ;δ1 8OH2 O值为 0 .9～ 12 .6下降到 - 8.2‰～ 6 .1‰ ;δDH2 O值由 - 48.3‰～ - 10 2 .6‰变为 - 5 4‰～ - 91.1‰。The Lenshuikeng Ag-Pb-Zn ore deposit is a porphyry-type, Rb-Sr isotope age from granite-porphyry rocks is 131.0±5.1 Ma, initial 87Sr/ 86Sr value of 0.711 05±0.002 75 for the Rb/Sr isochron. Rb-Sr isotope from form volcanic rocks is 101.3±4.1 Ma, initial 87Sr/ 86Sr value of 0.714 24±0.005 69 for the Rb-Sr isochron. K/Ar isotope age from granite-porphyry and volcanic roks are 83～138 Ma. Fluid in clusion-filling temperatures are 300℃forⅠ 1toⅠ 2 ,and 250-270℃ for Ⅱ 1toⅡ 3.Mineralogical data indicate that stage Ⅰand Ⅱ fluids had the following chemical composition: Logf O 2 from -30.12 to -40.78, logf CO 2 from 2.29 to 0.22, logf S 2 from -9.94 to-11.6, pH values from 3 to 4.8. δ 34S Values of sulfide minerals during stage Ⅱ 1toⅡ 3,show-4‰ to +5‰. δ 18O H 2O values of both minerals and fluids show 0.9‰ to 12.6‰ at stage Ⅱ 1 and then finally drop to -8.2 to 6.1l‰ during stage Ⅱ 3.δD H 2O values show -48.3‰ to -102.6‰ during stage Ⅱ 1 and during stage Ⅱ 3 for -54‰ to -91.1‰

关 键 词：同位素 银-铅-钾-矿床 江西冷水坑 

分 类 号：P597[天文地球—地球化学]