С�˰����������Ļ����ŵ���λ��������ɽ�����Σ�������¶�Ĵ��������������Ϊ�¿���— �������ҵ���Ҫ��ɲ��֡��û�����������Ҫ�ɻ����ʺͻ��������������ҵ���ɣ����л����������ҵ� SH��IMP �ʯ U- - Pb ������Ϊ 310. 7 ± 6. 5 Ma��������ԭ���γ�����ʯ̿���������ҵ�����Ԫ��������ʾ�С��߼ظƼ���׼����- - ������ϵ����ʯ���ص�; ΢��Ԫ�ر��ֳ� Th��Zr��Hf��Nd����b�� K ���Ը������� Ba��Sr��Nb��P��Ti ���Կ���; ϡ��Ԫ�ؾ������Ե���ϡ��Ԫ�ظ�������ϡ��Ԫ����Կ�����������н����Եĸ� Eu �쳣���ᡢ��ϡ��Ԫ�ط���̶Ƚ�ǿ������������ݻ��ص㼰���������ҵ��γɻ����ȣ��ۺ���ʾ�����ҵ�ԭ��Ӧ�γ��������������������ʱ�ڷ������Եı��ʱ������á�

The Huolongmen area in Xiao Hinggan mountains is tectonically located in the eastern Xingmeng oregenic belt�� A large area of exposed granitic complex is an important part of the Xinkailing- -Kele complex�� The granitic complex is mainly composed of granite and granodioritic mylonite�� Dating of the zircon U- -Pb SH��IMP�� concordant age of the granitic mylonite is 310. 7 ± 6. 5 Ma�� implying that their protolith formed in the Late Carbon- iferous�� Major elements of the granitic complex indicate medium to high potassium calc- alkaline and metaluminous to peraluminous in composition�� Trace elements demonstrate the enrichment of Th��Zr��Hf��Nd����b��K and de- pletion of Ba��Sr��Nb��P��Ti�� The samples are enriched in L��EE (light rare earth elements) and depleted in H��EE (heavy rare earth elements) with pronounced negative Eu anomalies��suggesting a high degree fractionation of L��EE and H��EE�� Based on the regional tectonic evolution characteristics and forming environment of granitic complex��we interpreted that their protolith formed in Late Paleozoic��but significant deformation and metamorphism occurred in Trassic��