Geochemical Characteristics and the Tectonic Setting of Amphibolites of the North Liaohe Group in Liaodong Area

Liaohe Group is one early proterozoic metamorphic unit which located in Liaodong area and it is divided into Southern Liaohe Group and Northern Liaohe Group.In order to discuss the tetonic setting of north-Liaohe Group,the petrographic characters of North-Liaohe Group amphibolites were analyzed.The results showed that the main minerals of amphibolites were the amphibolite and the plagioclase.The total rare elements ranged from 45.99 μg/g to 77.71 μg/g,belonging to deficient rare element type.The light rare elements are richer than heavy rare elements and their distribution patterns showed the right slope and had no Eu abnormity or poor positive abnormity.The features above discussed clarify that the protoliths of Amphibolites was the quartz tholeiitic and formed under ocean island arc tectonic-environment.