摘要
通过对胶东区域断裂构造时空演化的分析,提出郯庐大断裂的次级断裂为胶东金矿的控矿构造,并为导矿构造。晚燕山期区域右行走滑断裂活动产生的浅部张剪裂隙为容矿构造,其张裂变形产生的扩容作用是“泵吸”深部矿液上侵充填的驱动力。张剪断裂以脉动方式释放构造应力,实测差应力值为120~40MPa;从早到晚有衰减趋势。容矿断裂脉动活动可划分为脆性破裂和脆韧性扩张两种动力学状态或阶段,并制约着热液反应体系中成矿和控制反应进行的方向和强度,从而控制成矿元素的富集和分散。热液成矿反应体系的热力学演化与构造动力学条件的耦合是金富矿石形成的机制。
n the basis of studying the regional tectonic evolution ofeastern Shandong Province in China,the authors prove that the tension-shear fracture of Late Yanshan stage is favorable orebearing structure for the Jiaodong gold deposits,and the dilatation at the brittle splitting of fracture drived up mineralization solution from the deep.The structural differential stress value △σ measured by quartz dislocation density method for tension-shear fracture ranges over 120~40 MPa.Regional tectonic activities controlled the concentration of dispersed elements in ore mineralization through its effect on the thermdynamic parameters and conditions of the oreforming reaction system. During hydrothermal mineralization the activities of ore-bearing fracture can be divided into two stages:brittle splitting and brittle-tough tensile stages which created distinctly different gedynamic conditions in the geochemical thermdynamic system of the ore formation.In me laterstage of evolution of hydrothermal solution,as a result of crystallization of SiO2 and FeS2,the concentration of Au was increased in the residual ore -forming solution.High-grade ore localization during the hydrothermal processes resulted from a combination of thermodynamic evolution of hydrothermal system and the favorable tectonic dynamic conditions.
出处
《现代地质》
CAS
CSCD
1996年第2期213-217,共5页
Geoscience
基金
地质矿产部重要基础地质研究项目
关键词
金矿床
成矿构造
地球化学
动力学
ore-control fracture
tectonic-dynamic state
measurement of structural differential stress value △σ
ore-forming reaction system
Jiaodong gold deposit