伊春地区上游新村晚三叠世二长花岗岩体成因及就位机制

伊春-延寿花岗岩带上的晚三叠世二长花岗岩体是一套呈结构演化系列的岩石,岩石类型按结构可划分出一期结构、二期结构、末期结构的完整系列.岩石中普遍发育同源闪长岩包体,在岩石学、岩石化学及地球化学方面表现出明显I型花岗岩特征.花岗岩类产出动力学地质背景分析表明其形成于碰撞后构造环境,造山后伸展体制是这期花岗岩形成的重要原因,岩浆就位机制呈现出被动侵位的特点.

GENESIS AND EMPLACEMENT MECHANISM OF THE LATE TRIASSIC ADAMELLITE SERIES IN YICHUN AREA,HEILONGJIANG PROVINCE

The Late Triassic adamellite masses in the Yichun-Yanshou granite zone are a series of rocks with complete texture evolution.According to their textures,the rocks can be divided into types of first stage,second stage and last stage textures.The homoeogene diorite enclaves are broadly developed in the adamellite masses.The rocks show obvious characteristics of I-type granite in petrology,petrochemistry and geochemistry.Analysis on the occurring tectonic setting indicates that the granites were generated in the post-collision envir onment,and the post-orogenic extension system is the main condition for the forming of the granite.The magma emplacement mechanism shows passive characteris tics.