内蒙古碾子沟钼矿床成矿流体来源、演化及成矿机理

doi:10.13278/j.cnki.jjuese.20190121

摘要/Abstract

摘要： 内蒙古自治区碾子沟钼矿床地处华北地台北缘西拉木伦钼成矿带西段，为一典型的中型石英脉型钼矿床。该钼矿床矿脉（体）主要产于燕山早期二长花岗岩-钾长花岗岩内NNW、NW向断裂构造体系之中，成矿作用过程经历了黄铁矿±辉钼矿＋石英（Ⅰ）、辉钼矿＋黄铁矿±黄铜矿＋石英（Ⅱ）、黄铜矿＋黄铁矿±闪锌矿＋石英（Ⅲ）及石英±方解石（Ⅳ）4个阶段。系统的流体包裹体岩相学、包裹体组分析、包裹体显微测温研究表明，矿床初始成矿流体为高温、中低盐度（490~550℃，盐度（w（NaC1））2%~10%，50~62 MPa）均匀的NaCl-H₂O体系热液，δ¹⁸O_H₂O-SMOW（2.21‰）及δD_H₂O-SMOW（-68.9‰）表明其主要来源于岩浆热液；成矿流体上升并不断汇聚于容矿断裂空间，伴随温度、压力降低（380~460℃，26~40 MPa→360~420℃，25~30 MPa）而进入两相不混溶区，流体开始发生沸腾→强烈沸腾作用，导致成矿元素Mo大量沉淀富集成矿，成矿晚期残余流体与大气降水混合（δ¹⁸O_H₂O-SMOW为-2.41‰~2.51‰，δD_H₂O-SMOW为-110.1‰~-105.5‰），矿床属燕山早期中高温岩浆热液型钼矿床。

关键词: 碾子沟钼矿床, 石英脉型, 流体包裹体, 成矿流体演化, 内蒙古自治区

Abstract: Nianzigou molybdenum deposit is located in the western part of the Xilamulun molybdenum metallogenic belt at the north margin of North China Craton, which is a medium-sized typical quartz vein type deposit. The ore veins mainly occur in the NNW, NW trending faults developed in the monzonitic granite-moyite intrusions of Early Yanshanian. The hydrothermal mineralization can be divided into four stages:pyrite ±molybdenite+quartz(Ⅰ), molybdenite+pyrite ±chalcapyrite+quartz (Ⅱ), chalcopyrite+pyrite ±sphalerite+quartz (Ⅲ), and quartz ±calcite (Ⅳ). The systematic study on petrography of fluid inclusions, fluid inclusion assemblages,and micro-thermometry shows that the primary ore forming fluids are of high temperature (490-550℃),low-medium salinity NaCl-H₂O type solutions (10%-18%); their δ¹⁸O_H2O-SMOW(2.21‰)and δD_H2O-SMOW(-68.9‰)imply that they were originally from magmatic activities, and continuously up-rose and gathered into ore-controlling faults; later with the gradual decrease of temperature and pressure(380-460℃, 26-40 MPa→360-420℃, 25-30 MPa), the state of immiscible two-phase appeared, and the fluid began to boil, which resulted in the deposition of large amounts of Mo; at the late stage of the fluid evolution, the residual solution mixed with meteoric water. Nianzigou Mo deposit is a medium-high temperature magmatic hydro thermal deposit in Early Yanshanian.

Key words: Nianzi gou molybdenum deposit, quartz vein type, fluid inclusion, evolution of ore-forming fluids, Inner Mongolia Autonomous Region

中图分类号:

P618.65

孙丰月, 王睿, 王一存, 李顺达, 王可勇, 石开拓, 孙清飞, 王文元. 内蒙古碾子沟钼矿床成矿流体来源、演化及成矿机理[J]. 吉林大学学报(地球科学版), 2020, 50(3): 768-780.

Sun Fengyue, Wang Rui, Wang Yicun, Li Shunda, Wang Keyong, Shi Kaituo, Sun Qingfei, Wang Wenyuan. Origin, Evolution of Ore-Forming Fluids and Metallogenic Mechanism of Nianzigou Molybdenum Deposit, Inner Mongolia[J]. Journal of Jilin University(Earth Science Edition), 2020, 50(3): 768-780.

参考文献

[1] 曾庆栋, 刘建明, 张作伦,等. 华北克拉通北缘西拉木伦钼多金属成矿带钼矿化类型、特征及地球动力学背景[J]. 岩石学报, 2009, 25(5):1225-1238. Zeng Qingdong, Liu Jianming, Zhang Zuolun, et al. Mineralizing Types, Geological Characteristics and Geodynamic Background of Molybdenum Deposits in Xilamulun Molybdenum Polymetal Metallogenic Belt on Northern Margin of North China Craton[J]. Acta Petrologica Sinica, 2009, 25(5):1225-1238.
[2] 陈衍景, 张成, 李诺, 等. 中国东北钼矿床地质[J]. 吉林大学学报(地球科学版), 2012, 42(5):1223-1268. Chen Yanjing, Zhang Cheng, Li Nuo, et al. Geology of the Mo Deposits in Northeast China[J].Journal of Jilin University (Earth Science Edition), 2012,42(5):1223-1268.
[3] 张梅. 大兴安岭中南段铜多金属矿床成矿系统研究[D]. 北京:中国地质大学(北京), 2011. Zhang Mei. Study on the Metallogenic System of Copper-Polymetallic Deposits in the Middle-Southern Part of Da Hinggan Mountains, China[D].Beijing:China University of Geosciences(Beijing), 2011.
[4] 毛景文, 周振华, 武广,等. 内蒙古及邻区矿床成矿规律与成矿系列[J]. 矿床地质, 2013, 32(4):715-729. Mao Jingwen, Zhou Zhenhua, Wu Guang, et al. Metallogenic Regularity and Minerogenetic Series of Ore Deposits in Inner Mongolia and Adjacent Areas[J].Mineral Deposits, 2013, 32(4):715-729.
[5] 孟树, 闫聪, 赖勇,等. 内蒙古车户沟钼铜矿成矿年代学及成矿流体特征研究[J]. 岩石学报, 2013, 29(1):255-269. Meng Shu, Yan Cong, Lai Yong, et al. Study on the Mineralization Chronology and Characteristics of Mineralization Fluid from the Chehugou Porphyry Cu-Mo Deposit, Inner Mongolia[J]. Acta Petrologica Sinica, 2013, 29(1):255-269.
[6] 刘利, 曾庆栋, 刘建明,等. 内蒙古西拉木伦成矿带劳家沟斑岩型钼矿流体包裹体特征及地质意义[J]. 地质与勘探, 2012, 48(4):663-676. Liu li, Zeng Qingdong, Liu Jianming, et al. Characteristics of Fluid Inclusions from the Laojiagou Porphyry Mo Deposit in the Xilamulun Metallogenic Belt, Inner Mongolia and Their Geological Significances[J].Geology and Exploration, 2012, 48(4):663-676.
[7] Wu H, Zhang L, Wan B, et al. Re-Os and ⁴⁰Ar/³⁹Ar Ages of the Jiguanshan Porphyry Mo Deposit, Xilamulun Metallogenic Belt, NE China, and Constraints on Mineralization Events[J]. Mineralium Deposita, 2011, 46(2):171-185.
[8] Wu H, Zhang L, Wan B, et al. Geochronological and Geochemical Constraints on Aolunhua Porphyry Mo-Cu Deposit, Northeast China, and Its Tectonic Significance[J]. Ore Geology Reviews, 2011, 43(1):78-91.
[9] 马星华, 陈斌, 赖勇,等. 内蒙古敖仑花斑岩钼矿床成岩成矿年代学及地质意义[J]. 岩石学报, 2009, 25(11):247-258. Ma Xinghua, Chen Bin, Lai Yong, et al. Petrogenesis and Mineralization Chronology Study on the Aolunhua Porphyry Mo Deposit, Inner Mongolia and Its Geological Implications[J].Acta Petrologica Sinica,2009, 25(11):247-258.
[10] 马星华, 陈斌. 大兴安岭南段敖仑花斑岩钼(铜)矿床成矿流体来源与成矿作用:稳定同位素C、H、O、S和放射性Pb同位素约束[J]. 吉林大学学报(地球科学版), 2011, 41(6):1770-1783. Ma Xinghua, Chen Bin. The Sources of Hydrothermal Fluids and Mineralization in the Aolunhua Porphyry Mo-Cu Deposit, Southern Dahinggan Mountains:Constraints from Stable(C,H,O and S) and Radiogenic (Pb) Isotopes[J]. Journal of Jilin University(Earth Science Edition), 2011, 41(6):1770-1783.
[11] 马星华, 陈斌. 内蒙古敖仑花钼矿床地质特征、含矿斑岩地球化学及锆石Hf同位素研究[J]. 矿物学报, 2009, 29(增刊1):19-20. Ma Xinghua,Chen Bin. The Geology,Geochemistry of Ore Bearing Porphyry and Zircon Hf Isotope of Aolunhua Mo Deposit, Inner Mongolia[J].Mineral Journal, 2009, 29(Sup.1):19-20.
[12] 陈志广, 张连昌, 吴华英,等. 内蒙古西拉木伦成矿带碾子沟钼矿区A型花岗岩地球化学和构造背景[J]. 岩石学报, 2008, 24(4):257-267. Chen Zhiguang, Zhang Lianchang, Wu Huaying, et al. Geochemistry Study and Tectonic Background of A Style Host Granite in Nianzigou Molybdenum Deposit in Xilamulun Molybdenum Metallogenic Belt, Inner Mongolia[J]. Acta Petrologica Sinica, 2008, 24(4):257-267.
[13] 张作伦, 曾庆栋, 屈文俊,等. 内蒙碾子沟钼矿床辉钼矿Re-Os同位素年龄及其地质意义[J]. 岩石学报, 2009, 25(1):212-218. Zhang Zuolun, Zeng Qingdong, Qu Wenjun, et al.The Molybdenite Re-Os Dating from the Nianzigou Mo Deposit, Inner Mongolia and Its Geological Significance[J]. Acta Petrologica Sinica, 2009, 25(1):212-218.
[14] 张作伦, 刘建明, 曾庆栋. 内蒙古碾子沟钼矿床SHRIMP锆石U-Pb年龄、硫同位素组成及其地质意义[J]. 矿床地质, 2011, 30(6):1122-1128. Zhang Zuolun, Liu Jianming, Zeng Qingdong. SHRIMP Zircon U-Pb Dating and Sulfur Isotope Compositions of Nianzigou Molybdenum Deposit, Inner Mongolia and Their Geological Significance[J]. Mineral Deposit, 2011, 30(6):1122-1128.
[15] 任纪舜. 中国东部及邻区大地构造演化的新见解[J]. 中国区域地质, 1989, 4:289-300. Ren Jishun. Some New Ideas on Tectonic Evolution of Eastern China and Adjacent Areas[J].Regional Geology of China, 1989, 4:289-300.
[16] Zhang L C, Wu H Y, Wan B, et al. Ages and Geodynamic Settings of Xilamulun Mo-Cu Metallogenic Belt in the Northern Part of the North China Craton[J]. Gondwana Research, 2009, 16(2):243-254.
[17] 欧阳荷根. 大兴安岭南段拜仁达坝-维拉斯托银多金属矿床成矿作用及动力学背景[D]. 北京:中国地质大学(北京), 2013. Ouyang Hegen. Metallogenesis of Bairendaba-Weilasituo Silver-Polymetallic Deposit and Its Geodynamic Setting in the Southern Segment of Great Xing'an Range, NE China[D].Beijing:China University of Geosciences(Beijing), 2013.
[18] Roedder E. Fluid Inclusion Evidence for Immiscibility in Magmatic Differentiation[J].Geochimica et Cosmochimica Acta,1992, 56:5-20.
[19] András F, Bodnar R J. How Precisely Can the Temperature of a Fluid Event Be Constrained Using Fluid Inclusions?[J]. Economic Geology, 2018, 113(8):1817-1843.
[20] Brown P E, Hagemann S G.MacFlincor and Its Application to Fluids in Archean Lode-Gold Deposits[J].Geochimica et Cosmochimica Acta,1995, 59(19):3943-3952.
[21] Brain G R, Mark H R. Fluid Inclusion Evidence for Magmatic-Hydrothermal Fluid Evolution in the Porphyry Copper-Molybdenum Deposit at Butte, Montana[J]. Economic Geology, 2008,103(2):307-334.
[22] Heinrich C A. Fluid-Fluid Interactions in Magmatic-Hydrothermal Ore Formation[J]. Reviews in Mineralogy and Geochemistry, 2007,65:363-387.
[23] Kiemn L M, Pettke T, Heinrich C A. Hydrothermal Evolution of the EL Teniente Deposit, Chile:Porphyry Cu-Mo Ore Deposition from Low-Salinity Magmatic Fluids[J]. Economic Geology, 2007, 102:1021-1045.
[24] Audétat A, Li Wanting. The Genesis of Climax-Type Porphyry Mo Deposits:Insights from Fluid Inclusions and Melt Inclusions[J]. Ore Geology Reviews, 2017, 88:436-460.
[25] Clayton R N, O'Neil J R, Mayeda T K. Oxygen Isotope Exchange Between Quartz and Water[J]. Journal of Geophysical Research, 1972, 77:17.
[26] Taylor H P. The Application of Oxyen and Hydrogen Isotope Studies to Problems of Hydrothermal Alteration and Ore Deposition[J]. Economic Geology, 1974, 69(6):843-883.
[27] Honza C, Kalin K, Bentta P, et al. Zoned Base Metal Mineralization in a Porphyry System:Origin and Evolution of Mineralizing Fluids in the Morococha District, Peru[J]. Economic Geology, 2015,110:39-71.
[28] Seo J H, Guillong M, Heinrich C A. Separation of Molybdenum and Copper in Porphyry Deposits:The Roles of Sulfur, Redox, and Ph in Ore Mineral Depositoion at Bingham Canyon[J]. Economic Geology, 2015, 107:333-356.
[29] Heinrich C A, Günter D, Audétat A, et al. Metal Fractionation Between Magmatic Brine and Vapor, Determined by Microanalysis of Fluid Inclusions[J]. Geology, 1999,27(8):755-758.
[30] 王一存. 内蒙古西拉木伦成矿带铜钼多金属成矿作用研究与成矿预测[D].长春:吉林大学,2018. Wang Yicun. The Cu-Mo Minerlization and Metallogenic Prognosis of Xilamulun Metallogenic Belt,Inner Mongolia[D]. Changchun:Jilin University,2018.

Metrics

Viewed

Full text

Abstract

Cited

Shared

Discussed