辽宁北瓦沟地区铅锌矿床地质特征及找矿方向

Geological Characteristics and Prospecting Direction of the Lead-zinc Deposit in Beiwagou Area,Liaoning Province

北瓦沟地区位于营口—宽甸早元古代、印支—燕山期的Au-Ag-Cu-Pb-Zn-B成矿带内,区内构造发育,岩浆岩广布,成矿地质条件优越,具有较好的找矿前景。通过野外实地调查与室内地质资料分析相结合的方法,综合分析了区内铅锌矿地质特征及矿化特征,探讨了矿床成因及成矿地质条件,结果表明:1区内铅锌矿床成因类型为同生沉积-变质热液改造型和岩浆期后热液型,矿床的形成受地层、构造活动、岩浆活动共同影响,尤以吕梁时期构造变形作用为主;2吕梁期韧性剪切带构造对铅锌矿有明显的控制作用,为铅锌矿提供热源、动力、运移通道和富集空间;3与矿化有关的剪切带位于倒转褶皱正常翼的条带状大理岩中,总体走向NW。根据区内铅锌矿成矿条件及其外围地区铅锌矿化异常特征、分布规律,认为角砾状铅锌矿是主要找矿对象,早元古代辽吉花岗岩附近的辽河群大石桥组三段地层中的韧性剪切带发育部位是找矿有利部位。根据上述分析,圈定出了恒山里—王家堡子和大卫屯2个成矿远景区,为区内铅锌矿找矿工作提供参考。

Beiwagou area is located in the Au-Ag-Cu-Pb-Zn-B metallogenic belt,which is in the stage of Yingkou-Kuandian early Proterozoic and Indosinian-Yanshanian period. The ore-forming geological conditions of the area are favorable. Due to the developmental structure and the widely distributed magma rock,the prospecting prospects of the area are good. In order to further analyze the ore-forming conditions and the prospecting direction of the lead-zinc deposits in this area,the geological characteristics and the mineralization characteristics are analyzed in depth based on the basic geological research method by the way of the outdoor investigation and indoor geological data analysis. The results show that： 1the mineral deposit genetic type in Beiwagou area is syngenetic sedimentary-metamorphic hydrothermal reformation type and post magmatic hydrothermal type,the formation of the deposit is controlled by strata,magmatic activity and tectonic activity,the tectogenesis in Luliang period is the dominant factor; 2 the lead-zone deposits are controlled significantly by the ductile shear zone in Luliang period,the heat source,power,migration passage and enrichment space of the lead-zine mine are provided by the ductile shear zone in Luliang period; 3the ductile shear zone associated with mineralization is located in the normal wing of overfold,and the general strike of the ductila shear zone is NW. According to the mineralization condition and the anomaly characteristics and distribution regularity of the lead-zinc mineralization in the peripheral area,it can be concluded that the brecciform lead-zinc mine is the main search object,the favorable prospecting area in the third interval of Dashiqiao formation of Liaohe group with developmental ductile shear zone near the early Proterozoic Liaoji granites. Based on the above analysis results,two metallogenic prospecting regions named Hengshanli-Wangjiapuzi and Daweitun are delineated so as to provide reference for the prospecting work in this area.