米仓山地区岩浆活动与构造演化

THE MAGMATIC ACTIVITY AND TECTONIC EVOLUTION IN THE MICANGSHAN AREA,CHINA

扬子板块北缘自晚太古代至早震旦世，先后经历了地壳演化早期、沟－弧－盆和大陆裂谷三个大的发展阶段。与之有关的岩浆活动可划分为前吕梁期、吕梁期、晋宁期及澄江期；地壳演化的不同阶段、不同期次的岩浆岩在岩浆性质、活动方式和规模等方面有较大差别，各具特色。本文论述了各个时期岩浆活动特点、岩石成因及其与区域构造演化之间的密切关系，尤其是充分肯定了澄江期裂谷型岩浆岩在本区岩浆活动历史中的主导地位，这对进一步研究和重新认识扬子板块北缘地质构造演化史具有重要意义。

During the period of the Late Archean to the Early Sinian,there was experienced three main geotectonic evolutionary stages of the crust including the early stage of crust evolution,trench-arc-basin stage and cantinent rift stage the northern margin of the Yangtze craton plate.The corresponding magmatic activity can be divided into PreLuliang period,Luling period,Jinning period and Chengjiang period respectively.The magmatic rocks formed in different stages and evolutional terms of crust are with great differences in their features,activities and dimensions.It is discussed that the features of magmatic activities and rock formations during different terms as well as the close relations with regional tectonic revolution.It is inferred especially that the rift type magmatic rock of Chengjiang period was most important as the dominant position during the history of magmatic activity in this region,which is of great significance in further researching and reunderstanding the tectonic evolutionary history of Northern margin of Yangtze craton plate.