| 甘肃合作早子沟金矿床流体包裹体及硫铅同位素特征 |
| |
| 引用本文： | 陈瑞莉,陈正乐,伍俊杰,梁志录,韩凤彬,王永,肖昌浩,韦良喜,沈滔.甘肃合作早子沟金矿床流体包裹体及硫铅同位素特征[J].吉林大学学报(地球科学版),2018(1):87-104. |
| |
| 作者姓名： | 陈瑞莉 陈正乐 伍俊杰 梁志录 韩凤彬 王永 肖昌浩 韦良喜 沈滔 |
| |
| 作者单位： | 东华理工大学地球科学学院,南昌,330013
东华理工大学地球科学学院,南昌 330013;中国地质科学院地质力学研究所,北京100081
甘肃省地矿局第三地质矿产勘查院,兰州,730050
中国地质科学院地质力学研究所,北京,100081
中国地质大学(北京)研究生院,北京,100037 |
| |
| 基金项目： | 国家自然科学基金重点项目(U1403292)，中国地质调查局地质调查项目(1212011220936 |
| |
| 摘 要： | 早子沟金矿床是西秦岭西段近年来发现的大型金矿床之一。矿床产于中三叠世古浪堤组中,矿体产出与中酸性岩脉关系密切;矿体受断裂控制,呈脉状、条带状,少数似层状产出。含金石英脉可分为两个成矿期次,分别为含金粗粒石英脉期和多金属硫化物-金石英期;金属硫化物主要为辉锑矿、黄铁矿、毒砂等。辉锑矿石英脉型金矿石中流体包裹体主要为富液相的气液两相流体包裹体,均一温度为129.8~324.3℃,平均为203.2℃,盐度(w(NaCl))为1.22%~10.73%,平均为6.04%,成矿流体的密度平均为0.90g/cm~3,矿床的成矿平均深度约为2.00km;阴阳离子分析结果表明,流体包裹体液相成分主要为Na~+-SO_4~(2-)-Cl~-,单个流体包裹体激光拉曼显示流体包裹体中的气相成分主要为H_2O、CO_2和SO_2,个别样品显示有CO和CH_4,成矿流体为NaCl-H_2O-CO_2体系。流体包裹体研究揭示了早子沟金矿床辉锑矿-金成矿阶段的成矿流体为浅成中低温低盐度低密度流体,主要为岩浆水与地下水的混合热液,不同性质流体的混合作用和它们的沸腾作用是使金沉淀的重要因素。矿石中辉锑矿硫同位素组成很稳定,δ~(34)S_(V-CDT)值为-10.30‰~-8.10‰,平均为-9.33‰,表明硫主要为岩浆热液来源,并混有地层硫。矿石铅同位素组成显示~(206)Pb/~(204)Pb为18.166~19.027,~(207)Pb/~(204)Pb为15.608~15.741,~(208)Pb/~(204)Pb为38.249~39.275,矿石铅同位素组成为壳幔混合成因铅。根据早子沟金矿床特征,结合成矿流体性质及来源、成矿物质来源研究成果,推测甘肃早子沟金矿床应为岩浆期后低温热液金矿床。
|
| 关 键 词： | 流体包裹体 S-Pb同位素 早子沟金矿床 fluid inclusions S-Pb isotope Zaozigou gold deposit |
Fluid Inclusions and S-Pb Isotopes in Zaozigou Gold Deposit,Hezuo in Gansu Province |
| |
| Chen Ruili,Chen Zhengle,Wu Junjie,Liang Zhilu,Han Fengbin,Wang Yong,Xiao Changhao,Wei Liangxi,Shen Tao.Fluid Inclusions and S-Pb Isotopes in Zaozigou Gold Deposit,Hezuo in Gansu Province[J].Journal of Jilin Unviersity:Earth Science Edition,2018(1):87-104. |
| |
| Authors: | Chen Ruili Chen Zhengle Wu Junjie Liang Zhilu Han Fengbin Wang Yong Xiao Changhao Wei Liangxi Shen Tao |
| |
| Abstract: | The Zaozigou gold deposit is located at the west part of the Western Qinling Mountain range.It is one of the recently discovered large-scale gold deposits.The ore bodies are hosted in the Triassic Gulangti sedimentary rocks,and have a close relationship with the medium-acid dykes.The ore bodies and Indo-Sinian granitic veins are tightly controlled by faults;where the metal sulfides are stibnite,pyrite and arsenopyrite et al.Microscope observations showed that there are two-phase isolated primary inclusions in the gold-bearing quartz veins.Homogenization temperature falls in 129.8-324.3℃ with 203.2 ℃C as the average.The salinity w(NaCl) is 1.22％-10.73％ with 6.04％ as the average,indicating that the average density of ore-forming solution was 0.90 g/cm3,and the average depth was 2.00 km.The analyses of the fluid inclusion composition showed that the composition of gaseous phase is a NaCl-H2O-CO2 system,and the main fluid phase composition is a Na+-SO42--Cl--system.The Laser Raman spectroscopy revealed that the main composition in single inclusion are H2O,CO2 and SO2,only a few with CH4 and CO,suggesting that the ore-forming fluid in the Zaozigou deposit is a fluid of magmatic water mixed with ground water formed under low temperature,low salinity,and low density.The studies indicate that the mineralization has intimate relationship with two different proper fluid boiling and fluid mixing.The composition of the sulfur isotope is relatively stable,and the value of δ34 SV-CDT changes from-10.30‰ to-8.10‰ with the average value of-9.33‰,suggesting that the sulfur was mainly derived from the deep seated magma and a little from sedimentary strata.The lead isotopic ratios of ore samples are 206 Pb/204 Pb 18.166-19.027,207 Pb/204 Pb 15.608-15.741,208 Pb/204 Pb 38.249-39.275,indicating the crust and mantle mixing lead.The characteristics of the deposit,the nature and resource of ore-forming fluids and material suggest that the Zaozigou gold deposit is a kind of epithermal deposit related with magmatism. |
| |
| Keywords: | |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
|
