地质力学学报2025，Vol.31Issue(2)：169-196,28.DOI:10.12090/j.issn.1006-6616.2024106
赣西北大湖塘矿田石门寺钨矿床控矿构造解析
Analysis of ore-controlling structures of the Shimensi tungsten deposit,Dahutang ore field,northwest Jiangxi Province
摘要
Abstract
[Objective]The Dahutang tungsten ore field,located in the nearly EW-trending Jiuling uplift belt in northwestern Jiangxi Province,is a recently discovered area of concentrated,world-class,super-large,hydrothermal polymetallic tungsten deposits.It consists of two large tungsten deposits,namely Shimensi,Kunshan,and three medium-sized tungsten deposits,namely the Shiweidong,Dalingshang,Xin'anli deposits.The large Shimensi tungsten deposit is located in the north of the ore field,and the ore bodies are developed in Neoproterozoic granodiorite and Yanshanian granite.The mineralization is of quartz vein type,disseminated veinlet type,and hydrothermal crypto-explosive breccia type,and the three mineralization types occur regularly around the ore-forming granite mass.The ore bodies in the Shimensi tungsten deposit are obviously controlled by structure,but there is little research.Structure is the important ore-controlling factor.The analysis of ore-controlling structures and the construction of tectonic ore-controlling models can help to reconcile the formation and evolution of ore-forming structures and identify the main ore-controlling factors,which can provide technical support for prospection and prediction.[Methods]This study conducts a detailed field investigation of the ore-bearing fracture system,analyzes the combination of different types of ore-bearing fractures,explores the ore-forming conditions,and constructs a structural ore-controlling model.[Results]The research shows that the ore-bearing structure is a multi-directional small fault structure with the main trend being EW,followed by NEE and NWW;all the ore-bearing structures are present in a nearly elliptical distribution with EW-trending long axes.The ore-bearing structures change from the outside to the inside of the ore-forming granite,from those with conjugate dip at medium dip angles to those with sole outward dip at medium dip angles,and those with high dip angles;then hydrothermal crypto-explosion breccia appears in the center of the deposit.Among them,the ore-bearing conjugate shear fractures(with an X-shape in the profile)formed in the magmatic emplacement period little before mineralization in a tectonic stress field with a vertical maximum principal stress and a horizontal intermediate principal stress.The ore-bearing solely outward-dipping fractures with medium or high dip angles were formed as non-conjugate shear fractures and tension-shear fractures in the metallogenic period by hydrothermal crypto-explosion in a tectonic stress field with a vertical maximum principal stress and a horizontal intermediate principal stress.The hydrothermal crypto-explosion center formed in a tectonic stress field with a vertical maximum principal stress and similarly-sized intermediate and minimum principal stresses.[Conclusion]The ore-controlling structures of the Shimensi tungsten deposit are the emplacement structure of the ore-forming magmatic rock with an almost EW(NWW)-trending long axis and the hydraulic fracturing structure of the post-magmatic ore-forming fluid.The emplacement structure of the ore-forming magmatic rock,which was formed a little earlier and distributed over a larger area,developed mainly in the overlying surrounding rock(Neoproterozoic granodiorite)on the top of the ore-forming granite rock mass.The hydraulic fracturing structure of the post-magmatic ore-forming fluid was formed in the metallogenic period within a narrow distribution area in the upper and overlying surrounding rocks of the ore-forming granite rock mass.The latent explosion and hydraulic fracturing of ore-forming fluid instantly reduced the pressure of the ore-forming fluid,leading to the precipitation of ore-forming materials and the crystallization of valuable minerals,forming the tungsten deposits.The emplacement structure of the granite rock mass and the hydraulic fracturing structure of the ore-forming fluid are the sites of the tungsten ore body and control the development of tungsten ore body.The near EW(NWW)-trend of the mining area belongs to a concealed petro-controlling basement structure.This structure causes the long axis of the ore-forming granite rock mass to extend nearly EW and plays an indirect ore-controlling role.The NWW-trending faults such as F20 are neither the ore-conducting structures,nor the ore-controlling structures.They are ore-breaking,post-mineralization structures,with sinistral movement and normal shear sense.The NNE-trending concealed structure in the ore-field controls the distribution of the ore-forming magmatic rock belts and is a high-level petro-controlling structure.[Significance]This research can not only guide the exploration of the deeper and peripheral parts of the deposits—that is,further prospection should first search for concealed ore bodies at depth in the plunging part of the eastern and western ends of the near EW(NWW)-trending ore-forming granite rock body,and then search for other granites and fluid metallogenic systems in the area where the concealed ore-forming granite rock mass develops—but also has a demonstrative effect for studies of ore-controlling structures in similar deposits in southern China,enriching the theory of ore-controlling structures for high-temperature hydrothermal deposits.关键词
含矿构造/控矿构造/控岩构造/花岗岩体侵位构造/液压致裂构造/石门寺钨矿床Key words
ore-bearing structure/ore-controlling structure/petro-controlling structure/intrusion structure of granite rock mass/hydraulic fracturing structure/Shimensi tungsten deposit分类
地质学引用本文复制引用
陈柏林,高允..赣西北大湖塘矿田石门寺钨矿床控矿构造解析[J].地质力学学报,2025,31(2):169-196,28.基金项目
国家重点研发项目(2016YFC0600207,2017YFC0602602) （2016YFC0600207,2017YFC0602602）
中国地质调查局地质调查项目(DD20242868) （DD20242868）
国家自然科学基金项目(42072227,42172258)This research is financially supported by the National Key R&D Program of China(Grant Nos.2016YFC0600207 and 2017YFC0602602),the China Geological Survey Project(Grant No.DD20242868),and the National Natural Science Foundation of China(Grant Nos.42072227 and 42172258). （42072227,42172258）
