辽西石洞沟金矿地质特征及找矿方向探讨

Discussion on the Geological Features and Prospecting of the Shidonggou Gold Deposit in Western Liaoning Province

石洞沟金矿位于华北地台北缘的冀东-辽西金多金属成矿带东段,属产于元古宙隆起带内碳酸盐岩中的微细浸染型金矿。据矿体赋存围岩的不同,可分为两种矿石类型:赋存于雾迷山组上部燧石条带白云质灰岩碎裂岩带中的硅质角砾岩型和赋存于铁岭组二段含锰灰岩蚀变破碎带中的破碎蚀变岩型。通过对矿床地质特征的分析,认为矿体产出严格受老马家推覆构造控制,该推覆构造既是导矿构造,又是储矿构造。两种不同类型的金矿化应是该推覆构造所形成的同一成矿系统、同一成矿机制作用的产物。结合矿区地质环境、矿体产出特征与微量元素特征以及矿床成因机制分析,初步认为该矿床成因与深部岩浆或与火山隐爆作用有关,属浅成低温-超低温热液充填型矿床,并具有多期矿化叠加的特征。同时,总结矿体赋存规律,进一步指出该区勘查工作方向,认为该区找矿前景广阔。

Shidonggou gold ore deposit is located in the north edge of North China Platform,the East part of the Gold-polymetallic ore belt from eastern Heibei Province to western Liaonong Province.Belong the micro-disseminated gold deposit,produced in the Mesoproterozoic carbonate uplift zone.According to the different rock ore body,can be divided into two ore types：The siliceous breccia and the fractured altered rock type.That were hosted in chert bands of dolomitic limestone in the cataclastic rock band of Wumishan group top,and in the Mn-limestone altered fracture zone of the second sections of Tieling group.Through the analysis of geological characteristics,Ore output is strictly Controlled by the laomajia Nappe-Structure.The nappe structure is lead ore,but also a reservoir host structure.Two different types of gold should be formed by the nappe structure of the same ore-forming system,the role of the same metallogenic mechanism of the product.Combination of geological environment,production characteristics and trace element characteristics of ore bodies,and deposit formation mechanism,the preliminary view that the genesis and the deep magma or volcanic cryptoexplosion related to an epithermal-low warm liquid filling type deposits,and superposition of mineralization with multiple features.At the same time,summarization of metallogenic regularities,further pointed out that the direction of exploration area,it is considered that the prospecting prospect.