吉林珲春东北部中生代侵入岩——一个中性—酸性双峰式岩系的演化和形成环境

MESOZOIC INTRUSTVE ROCK SERIES IN NORTHEASTERN HUNCHUN, JILIN—EVOLUTION AND FORMATION ENVIRONMENT OF AN INTERMEDIATE-ACIDIC BIMODEL ROCK SERIES

地质调查和年代学资料表明,研究区内早燕山期侵入岩为一套中性—酸性双峰式岩系。通过岩石学、矿物学和地球化学方面的研究,对该岩系的成分演化特征、形成的构造环境进行了较细致的论述,得出该岩系是一个具不连续演化特点的钙碱性岩系,形成于破坏性板块边缘的张性环境,相当于Ⅰ型花岗岩系,属于环太平洋岩浆作用的内容。

Geologic and geochronic data show that the intrusive rocks of early Yanshanian period in the study region is an intermediate-acidic bimodel rock series. Through studies of petrology, mineralogy and geochemistry,this paper obtaines a detailed description about the compositional evolution and structural environment of this rock series. It is concluded that the rock series is a calc-alkaline series with a discontinuous evolution trend. Meanwhile, it is pointed out that the rock series is a I-type granitic series formed in the tensile tectonic environment along destructive plate margin,which belongs to the circum-Pacific magmatism.