山东胶东金矿成矿地质背景初论

胶东地区的基底地质构造演化经历了陆核形成期、陆壳增生期和汇聚定型期3个主要阶段,古元古代克拉通化汇聚碰撞作用的形成使得原始的绿岩带矿源岩系活化改造;三叠纪华北板块与扬子板块间陆陆碰撞形成了山东东部的胶南-威海造山带,碰撞造山作用使克拉通地体再活化,二大板块的物质成分在区内重新熔合分配并促使金元素转移富集;侏罗-白垩纪时期太平洋板块对欧亚板块的强烈洋陆俯冲作用,形成了活动大陆边缘俯冲造山带的大陆弧花岗岩,包括玲珑序列二长花岗岩组合、郭家岭序列花岗闪长岩组合和伟德山序列花岗岩组合,这些花岗岩的强烈岩浆活动为金元素迁移成矿提供了热驱动;巨型走滑系统即郯庐断裂带及其巨大的左型走滑系统及其所形成的次级羽状断裂系统为

Primary Discussion on Mineralization Geological Background of Jiaodong Gold Deposits in Shandong Province

Basal geological tectonic evolution in Jiaodong area has experienced three main development periods, they ara continental nucleus formation period, continental crust proliferation period and Continental crust convergence and setting period. The formation of the Paleoproterozoic cratonization convergence and collision made the activation and modification happened in source rock series in original greenstone belt. Triassic continental collision between north China plate and the Yangtze plate formed Jiaonan-Weihai orogenic belt in eastern Shandong. The collision orogeny contributed to the reactivation of craton land body. The fusion distribution of material compositions in two plates made the gold elements transfer and enrichment. Stong oceanic subduction from Pacific Plate to Eurasian plate during Jurassic and Cretaceous period formed the continental arc granite in active continental margin subduction orogenic belt, including monzogranites in Linglong sequence, granodiorite in Guojialing sequence, and granite in Weideshan sequence. These strong magmatic activity provide a thermally driven gold metallogenic element migration. The giant strike slip system, such as Tanlu fault zone and its huge left type strike slip system and its secondary pinnate fault system provide a deep source channel and a suitable precipitation place for the migration and enrichment of gold element. This special " four-in-one " metallogenic geological background and their interaction process influence the metallogenic environment in Jiaodong area. The characteristics are rather unique and unrepeatable.