吉林集安群斜长角闪岩特征及古构造环境浅析

The amphibolite characteristics and plaeostructure environment in the Ji′an Group of Jilin province

吉林南部古元古代集安群广泛分布于通化市以南大泉源—财源—清河一带，构成了清河隆起的主体。该群自下而上包括蚂蚁河组、荒岔沟组和大东岔组。在蚂蚁河组和荒岔沟组中含有大量的斜长角闪岩，其岩石学、岩石化学特征表明原岩属基性玄武岩，而且以碱性玄武岩系列为主，岩石地球化学特征表明属大陆板内玄武岩，前组中兼有大洋玄武岩特征，反映出两组均产出于大陆板内环境。玛蚁河期陆壳较薄，具原始过渡陆壳特征，荒岔沟期陆壳增厚，接近现代陆壳。两者间存在转化、逐渐克拉通化过程，代表不同地质环境下的产物。

The Daquanyuan-Caiyuan-Qinghe areas of Tonghua City,the Plaeoproterozoic Ji′an Group in the southern part of Jilin province is widely distributed,where a main upwelling body in the Qinghe area was formed The Ji′an Group includes Mayihe Formation,Huangchagou Formation and Dadongcha Formation from lower to upper,there are large quantities of amphibolites in the Mayihe Formation and Huangchagou Formation,the petrography and petrochemical characteristics show that the initial rock belongs to basic basalt and is primarily alkaline basalt;the petrochemical character shows that it belongs to continental intraplate basalt and has oceanic basalt character,exhibiting that both of formation occurred in the continental intraplate environment;the continental crust of the Mayihe period is thinner and has an original intermediate continental crust character; the continental crust thickened in the Huangchagou period,simillar to modern one The two types have the gradual transformations of cratonization,representing the products in different geologic setting