摘要
在前人的工作基础上,我们根据近5年来的研究认为,金矿储量占全国约四分之一的胶北隆起是一个独立地体,它的四周有明确的边界断层,如郯庐断裂、平度—莱西断裂和荣城—青岛—五莲—日照—海州断裂(即榴辉岩带)分别与其相邻的鲁西地体、胶南地体和胶东南—苏东北—黄海地体分开。胶北地体金矿富集规律长期未被搞清的原因,除对其构造环境尚未认识清楚外,主要是对其早前寒武纪地层(>1850Ma)缺乏正确划分,从而对正确认识这个具有典型克拉通性质的胶北地体的地质演化发展。
The Precambrian strata of the Jiaodong Group are dealt with in this paper. This group was regarded to be Archean in age and is marked by the gravel-bearing parametamorphic rocks characteristic of basal conglomerate. According to the lithological characters, data on siotopic age, patterns of REE distribution and the ratio of trace elements of parametamorphic rocks of the 'Jiaodong Group', and based on comparing them with the Early Precambrian strata in the North China Platform and other craton of the world, the authors confirmed that the 'Jiaodong Group' established previously can be divided into three parts. The lower part is the Archean Jiaodong Group, ranging from 25550 to 3000 Ma and consisting mainly of the first-stage greenstone. The middle pact, the Qishan-Linjiazal Group is the lower part of the Early Proterozoic, ranging from 2550 to 2300 Ma and consisting of the second-stage greenstone. The upper part is the Jianshan Group and Fenzishan Group, which have been merged into one group, the Jianshan-Fenzishan Group, ranging from 2300 to 2000 Ma and consisting of khodalite. Hence, the Early Precambrian of Jiaobei may be correlated with the other craton of the world.
出处
《地层学杂志》
CSCD
北大核心
1992年第3期161-170,共10页
Journal of Stratigraphy
基金
国家自然科学基金
