作　　者： ; ; ; ; ; (陈兴高）;

机构地区： 南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室

出　　处： 《地质学报》 2013年第3期375-383,共9页

摘　　要： 哈达特陶勒盖铅锌矿床处于华北板块与西伯利亚板块交汇部位,是二连浩特-东乌旗多金属成矿带中新发现的一个中型铅锌矿床。本文在野外地质工作基础上,通过流体包裹体,氢、氧、硫和铅同位素的研究,深入探讨哈达特陶勒盖铅锌矿床形成机制。流体包裹体研究显示,均一温度介于195～408℃之间,均值为332.5℃;盐度介于1.40%～11.93%NaCleq.之间,均值为4.87%NaCleq.;流体密度介于0.609～0.890g/cm3之间,均值为0.720g/cm3;温度直方图显示,流体呈350～370℃和230～250℃两个峰值,其中230～250℃与成矿密切相关,350～370℃则代表成矿早期流体温度。流体形成压力约13.0MPa,推测深度约1.3km。激光拉曼测试结果显示,成矿流体属H_2O-NaCl体系,含有少量的CO_2。H、O同位素研究显示,流体演化成矿主要为岩浆水和大气水混合作用;矿石硫、铅同位素组成具有变化范围窄、相对均一的特点(δ~34S=4.0‰～6.1‰,^(206)Pb/^(204)Pb=18.311～18.467,^(207)Pb/^(204)Pb=15.590～15.636, ^(208)pb/^(204)pb=38.253～38.393),反映了成矿物质主要来源于岩浆。上述研究表明哈达特陶勒盖铅锌矿属于浅成中温热液矿床。 The Hardat Tolgoi Pb-Zn Deposit, located in the assembly belt of the North China Plate and the Siberia Plate, is a new medium-sized Pb-Zn deposit in the Erenhot-Dongwuqi polymetallic ore belt. Based on the field exploration, study of fluid inclusion, and H, O, S and Pb isotopic compositions, this paper discussed the fluid evolution and metallogenic mechanism of the ore deposit. Fluid inclusions study suggests that the mineralization homogenization temperature ranges from 195℃ to 408℃ with an average of 332.5℃, the salinity from 1. 40% to 11. 93% NaCleq. with an average of 4. 87%NaCleq. , and the density 0.61 g/cma to 0.89 g/cm3 with an average of 0.72 g/cm3. The histogram diagram shows two peak values, one ranging from 230℃ to 250℃ may be related with metallogenisis; the other from 350℃ to 370℃ may represent the early metallogenic fluid temperatrue. It was estimated that fluid formed under the pressure of about 13.0 MPa and the depth of about 1.3 km. Test results of the Laser Raman analyses indicate that the ore forming fluids belonged to the H2O-NaC1 system with little CO2. The study of hydrogen and oxygen compositions indicates that the ore-forming fluid of the Hardat Tolgoi Pb-Zn deposit mainly derived from magmatic water mixed with meteoric water. S and Pb isotopic compositions of the ores are characterized by narrow change range and relatively homogeneity, with δ34S of 4. 0‰ to 6. 1‰~ 206Pb/204Pb of 18. 311 to 18. 467, 207Pb/204pb of 15. 590 to 15. 636, 208Pb/204Pb of 38. 253 to 38. 393. Both the S and Pb isotopic compositions of ore indicate that the metallogenic materal were derived from magma. All of this suggest that the Hardat Tolgoi Pb-Zn deposit is a shallow mesothermal deposit.

关 键 词： 流体包裹体 稳定同位素 成矿机制 哈达特陶勒盖 内蒙古阿巴嘎旗

领　　域： [天文地球] [天文地球]