山西灵丘县梨园金矿地质特征及控矿因素分析

Geological Characteristics and Ore-controlling Factors of Liyuan Gold Deposit,Shanxi Province

山西梨园金矿位于太行山构造—岩浆—多金属成矿带上,出露地层为新太古界阜平群条带状片麻岩夹斜长角闪岩。矿体总体呈手掌状,主要赋存于NNE向构造带中。矿石中金属矿物主要为黄铁矿,其次为方铅矿、闪锌矿和黄铜矿,非金属矿物主要有石英、钾长石、斜长石和绢云母,贵金属为自然金(银金矿)。矿区围岩蚀变主要有硅化、绢云母化和黄铁矿化,与金矿化关系密切。矿床的形成经历了热液期和表生期,其中热液期(主成矿期)又可划分为石英硅化阶段、石英—黄铁矿阶段、石英—硫化物阶段和石英—碳酸盐阶段。通过野外地质调研和室内分析,总结了含矿围岩及构造控矿规律,指明了找矿标志,并分析了成矿作用,认为梨园金矿为受断裂破碎带控制的岩浆热液蚀变岩型金矿。研究成果为区内找矿提供一定的科学依据。

Liyuan gold deposit is located in the tectonic-magmaic-polymetallic metallogenic belt of Taihang Mountain.The outcropping strata are mainly banded gneiss and amphibolite of Neo-Archean Fuping Group. The orebody is generally hand-shaped and mainly occurs in the NNE-trending structural zone.The metal minerals in ore are mainly pyrite,followed by galena,sphalerite and chalcopyrite. The non-metallic minerals are mainly quartz,potassium feldspar,plagioclase and sericite.The precious metal is natural gold(silver-gold ore). The wall-rock alteration closely related to gold mineralization are mainly silicification,sericitization and pyrite mineralization.The formation of the deposit can be divided into two episodes,including hydrothermal episode and epigenetic episode.The hydrothermal episode is the main mineralization period,which can be divided into four stages,namely,quartz silification stage,quartz-pyrite stage,quartz-sulfide stage and quartz-carbonate stage. Based on field geological survey and indoor analysis,the ore-bearing wall-rocks and strutural ore-controlling raw were summarized,the prospecting mark was specified,and the metallogenic process was preliminarily analyzed. It is considered that Liyuan gold deposit belongs to magmatic hydrothermal altered rock type gold deposit controlled by fracture zone.The results provide certain scientific basis for gold prospecting in this area.