云南兰坪李子坪铅锌矿床的控矿构造、碳和氧同位素及稀土元素地球化学特征  

Structural control,oxygen and carbon isotope,and REE geochemistry of Liziping Pb-Zn ore deposit,Lanping Basin,Yunnan Province

作　　者：胡茂德[1,2] 张洪瑞[1] 贾敬伍[1,2] 刘于源 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质矿业总公司,北京100029 [3]中国地质大学地球科学与资源学院,北京100083

出　　处：《矿床地质》2015年第5期1057-1071,共15页Mineral Deposits

基　　金：国家自然科学基金项目(编号:41472067;41403043;41320104004;41273050和41302067);中国地质调查局项目(编号:1212011220908);国际地学对比计划IGCP/SIDA-600项目联合资助

摘　　要：李子坪铅锌矿床位于青藏高原东缘的兰坪盆地内,属于白秧坪矿集区的一部分,矿体主要受构造裂隙控制,构造对该矿床具有重要的控制作用。文章对该矿床进行了构造解析,并结合地球化学数据,讨论了该矿床的形成过程。研究表明,李子坪铅锌矿床主要发育3期构造变形:早期为近南北走向的褶皱构造,中期为西倾近似等间距的数条逆断层,晚期形成北西西向与北东东向的平移断层。矿体主要受晚期2组平移断层的控制。各类方解石的δ^(13)C_(PDB)值变化范围为-1.3‰^-2.3‰,平均值-1.7‰;δ^(18)O_(SMOW)值范围为6.9‰~21.0‰,平均值14.8‰。所测各类方解石的∑REE均小于30×10^(-6),∑HREE无明显变化,而∑LREE具有较明显差异,δEu均小于1,显示中等铕的负异常,表明成矿流体存在一定的演化规律。热液矿物方解石中的碳来源于海相碳酸盐岩的溶解作用,氧同位素结果表明成矿流体有大气降水渗入。综合分析认为,李子坪矿床应该为碰撞造山作用下形成的、矿体赋存于构造裂隙破碎带中的铅锌矿床。Located in the Lanping basin of the eastern Himalayan Syntaxis, the Liziping Pb-Zn ore deposit belongs to the Baiyangping silver-copper polymetallic ore concentration area. Orebody is mainly controlled by structure frac- ture zones. Structure played an important controlling role in Liziping lead-zinc mineralization. The structural analysis of the ore deposit and the geochemical ore-forming fluid study contribute to understanding the formation process of the ore deposit. In this paper, based on catalog of the ore adit, the authors analyzed ore-controlling structure of the ore deposit in detail and, what is more, with the ore-forming fluid data, carried out the effective constraint on the ore-forming conditions. The results show that the Liziping ore deposit mainly experienced three periods of tectonic deformation. In the early time, the strata of Liziping ore deposit developed a nearly NS-trending fold structure. In the middle period, several westward dipping approximately evenly spaced thrust faults were formed in the rocks. In the last stage, NW-striding and SW-striking strike-slip faults were formed. Orebody was mainly controlled by the two groups of strike-slip faults of the last stage. Ore structure is massive, breccia, disseminated in form, ~13CeDB values of all kinds of calcite are - 1.3‰-- - 2.3‰, averaging - 1.7‰. δ18OSMOW values vary in the range of 6.9‰--21.0‰, averagingl4.8%. ∑REE（ × 10^-6 ）values of all kinds of calcite are lower than 30.∑ HREE has no obvious change and ∑ LREE has obvious difference. δEu values are lower than 1, exhibiting a medium europium negative anomaly. δCe has no significant anomalies. These features indicate that the evolution of the ore-forming fluid obeyed certain evolution regularity. The research results show that the C from the ore-forming fluid in the Liziping Pb-Zn deposit was derived from marine carbonate solution, whereas meteoric waters constantly entered the ore-forming fluid through percolation. The ore-forming fluid was in the form of underg

关 键 词：地质学 控矿构造 碳 氧稳定同位素 稀土元素 李子坪铅锌矿床 

分 类 号：P618.42[天文地球—矿床学] P618.43[天文地球—地质学]