山东下潘格庄矿区金矿成矿地质特征及成因浅析

Geological Characteristics and Genesis of Gold Mineralization in Xiapangezhuang Mining Area, Shandong Province

下潘格庄矿区金矿矿床受牟平–乳山断裂带次级断裂构造控制,区内断裂破碎带是主要的导矿、控矿、赋矿断裂。矿体主要呈脉状、小透镜体、楔状赋存于玲珑序列九曲单元(J3ηγLJ)蚀变带内,蚀变带内主要岩性为黄铁矿化碎裂岩、褐铁矿化碎裂岩、绢英岩化花岗岩、绢英岩化碎裂岩,蚀变带顶底板围岩为弱片麻状细中粒含石榴二长花岗岩、黑云片麻岩、煌斑岩、正长斑岩等变质岩及脉岩,近矿围岩受热液影响,发育的黄铁矿化、硅化、绢云母化与金矿生成关系密切。区内主要载金矿物矿物为黄铁矿,黄铁矿的颜色、晶形、赋存状态决定其含金性高低,次要载金矿物为含矿热液活动有关的绢英岩化、硅化、钾化等。本次工作以前人研究工作为基础,结合本人对矿区金矿的成矿地质特征、成矿物质来源、矿化富集规律、矿床成因进行了总结和研究,认为该矿区金矿矿床成因类型属中温热液裂隙充填交代型金矿床,沿断裂构造破碎带深部探索隐伏矿具有较好的找矿潜力。

The gold deposit in Xiapangezhuang mining area is controlled by the secondary fault structure of Muping Rushan fault zone. The fault fracture zone in the area is the main ore guiding, ore controlling and ore hosting fault. The ore body mainly occurs in vein, small lens and wedge shape in the Jiuqu unit of Linglong sequence (J3ηγLJ) in the alteration zone, the main lithology in the alteration zone is pyritized cataclastic rock, limonitized cataclastic rock, sericitized granite and sericitized cataclastic rock. The surrounding rocks of the top and bottom of the alteration zone are weakly gneissic fine to medium grained garnet bearing monzonite, biotite gneiss, lamprophyre, syenite porphyry and other metamorphic rocks and dykes. The developed pyritization, silicification and sericitization are closely related to the generation of gold deposits due to the influence of thermal fluid in the surrounding rocks near the ore. The main gold bearing mineral in the area is pyrite. The color, crystal form and occurrence state of pyrite determine its gold bearing property. The secondary gold bearing minerals are sericitization, silicification and potassium mineralization re-lated to ore bearing hydrothermal activities. This work is based on the previous research work and combined with my own summary and Research on the ore-forming geological characteristics, ore-forming material sources, mineralization enrichment rules and deposit genesis of the gold deposits in the mining area. It is believed that the genetic type of the gold deposits in the mining area belongs to the mesothermal hydrothermal fissure filling metasomatic gold deposit, and the deep exploration of hidden deposits along the fault structural fracture zone has good prospecting potential.