胶东东部金青顶金矿床围岩蚀变岩带的地球化学、形成机理及找矿方向的研究

RESEARCH ON GEOCHEMISTRY, FORMATIONAL MECHANISM OF ALTERATION ZONES IN THE HOST ROCKS OF JINQING DING GOLD DEPOSIT AND ITS SIGNIFICANCE ON THE FURTHER GOLD EXPLORATION IN JIAODONG AREA

通过对金青顶金矿床地质、蚀变岩石类型、蚀变矿物、蚀变岩岩石化学、痕量元素地球化学、蚀变岩石英包体的物理化学、氢氧同位素地球化学的研究,确定了主要金矿体、主要成矿阶段的围岩蚀变岩的分带特征.研究了围岩蚀变岩带的形成机理,建立了壳源深熔花岗岩-热液流体-碱酸交代作用的蚀变岩带形成模式.指出了围岩蚀变岩带的找矿信息.

Jinqingding Au-deposit is one of the large - sized deposits in Jiaodongg area yet found in resent years. It is a crustal-sourced-anatectic granite-related mesothermal quartz vein Au - deposit (270-215℃), occuring in NNE-NE fracture zone developed in Rushan biotite - monzogranitte of the early Cretaceous age (134.4 ± 3.81my).Based on the rdsults of geology, altered rock types, altered mineralogy, petrochemistry, geochemistry of trace elements inclding REE and O, H isotopes, physicochemistry of fluid inclusion are determined the major wallrock alterations zoning and the maior metallogenic stages and the temporal evolution and spatial distribution of the alteration zones i. e. fresh granite - potasium granite - sericite - potasium granite - quartz - sericite rock - pyrite - sericite rock - gold vein. And the structure environment, time interval in which the alteredd rocks were formed are elucited. Further more, are put forward the marks of petrology, mineralogy and geochemistry to discreminate altere rock zones and estalished the formational model for alteration (i. e. identity of structural environment - hydrrothermal fluid - physicochemistry condition - replacement) and located 4 targers for future Au-exploration in Rushan area.