山东乳山蓝家庄金矿地质特征及矿床成因研究

Geological Characteristics and Origin of Lanjiazhuang Gold Deposit in Rushan of Shandong Province

摘要:

蓝家庄金矿床位于牟平乳山金成矿带南部，为一处严格受构造控制的蚀变岩型为主石英脉型次之的大型金矿床。控矿构造内煌斑岩的大量出现，显示控矿构造具有贯通下地壳的特点，可以为幔源含矿岩浆流体浅部就位提供空间条件。研究认为矿化蚀变带中心发育的正长斑岩与金成矿关系密切；矿床地质特征和穿插关系显示矿床形成经历了4个热液成矿期，第Ⅱ和第Ⅲ成矿阶段(石英黄铁矿和石英多金属硫化物阶段)为主要的金成矿期，矿物组合特征显示应属浅成低温热液矿床；矿床深部可能发育的超壳断裂和斑岩体，为研究胶东金矿矿床成因提供了新视角。

Abstract:

Lanjiazhuang gold deposit is located in the south part of Muping-Rushan gold metallogenic belt. It is a large scale gold deposit with altered rock type strictly controlled by tectonics and quartz vein type followed by quartz vein type. A large number of lamprophyre occur in the ore-controlling structure. It is showed that the ore-controlling structure has the characteristics of penetrating the lower crust. It can provide space conditions for shallow emplacement of mantle-derived magmatic fluid. It is regarded that the syenite porphyry developed in the center of the mineralized alteration zone has close relation with gold mineralization. As showed by geological characteristics and interpenetration relationship of the deposit, the formation of the deposit has experienced four hydrothermal mineralization stages. Ⅱ and Ⅲ metallogenic stages (quartz-pyrite and quartz polymetallic sulphide stage) are main gold mineralization stages. As showed by mineral combination characteristics, it should belong to the epithermal deposit. The super-shell fault and porphyry system that may develop in the deep part of the deposit provides a new perspective for studying the origin of gold deposits in Jiaodong area.