���ɹ�����������λ�ڴ��˰����ж��˰��ؿ��ϣ�������¶�����������������ҡ����ʯ�� LA-ICP-MS U--Pb ��������ʾ�������������γ���335 ± 5 Ma�������������γ���313 ± 3 Ma�������������γ���320 ± 1 Ma����������������������Ϊ����������ڻ������ҽ���IJ���������ҽ��ľ�λ�������ʱ�ڹ�������պ�����Ǹ�����������Ҫ��ϵ�����������ҵ�176Hf /177Hf Ϊ0. 282 833 �� 0. 282 951��εHf ( t) Ϊ+ 1. 1 �� + 5. 6��TDM2 Ϊ525 �� 752 Ma����ʾ�����ҵ�Դ��Ϊ��Ԫ�Ŵ�—�������ʱ�ڿ�������Դ�Ļ����µؿ����ʡ����Ŀǰ�ѷ���Ļ�����Sr --Nd ���ʯHf ͬλ�����ϣ���Ϊ�˰��ؿ���ܴ���Ԫ�Ŵ��Ϳ�ʼ�ؿ����������ڼ�������Ԫ�Ŵ�—���������

Taerqi area is located at Xing'an Block in central Great Xing'an Range��where exposed widespread Late Paleozoic granites�� Ages dated by zircon LA-ICP-MS U--Pb are 313 ± 3 Ma��335 ± 5 Ma and 320 ± 1 Ma for monzogranite��syenogranite and granodiorite��respectively��indicating the Taerqi granites experienced multi-stage magamatism in the Late Paleozoic�� There is a genetics of the emplacement of granitic magma was related closely to the oceanic crust subduction during the closure of the Paleo-Asia Ocean in Paleozoic�� 176Hf /177Hf ratios of zircons from the granodiorite range from 0. 282 833 to 0. 282 951��corresponding to εHf ( t) values from + 1. 1 to + 5. 6 and TDM2 from 525 to 752 Ma�� Hf isotopic characteristics imply that these granites originated from the mafic lower crust formed during Neoproterozoic-Early Paleozoic with depleted mantle affinity�� Combined with the Sr --Nd and zircon Hf isotopic data published��it is concluded that the crustal accreation event in Xing'an block mainly took place at Neoproterozic-Phanerozoic��probably started at the Mid-Proterozoic��