�����������ϲ�—��ɽ�͵����㷺������״���������ҡ�������һ�״����������Ϊ���ɫ�д�����״���������ң���״���߾��ɼس�ʯ��ʯӢ��ɣ������ɼس�ʯ��б��ʯ��ʯӢ�ͺ���ĸ��ɣ��ֲ�������ʯ����ʯSiO2 ����69. 58% �� 75. 96%; ���Na2O + K2O Ϊ7. 22% �� 8. 45%��K2O/ Na2O Ϊ1. 07 �� 1. 43 ( σ = 1. 58 �� 2. 47) ��Ϊ�Ƽ��Ի����ҡ�ΣREE Ϊ178. 68 × 10 �� 6 �� 464. 75 × 10--6�� ( La /Yb) N = 11. 6 �� 20. 22������ϡ������������δEu = 0. 17 �� 0. 34�������쳣����Ը�Rb��Th��U�� Nd��La��Pr ��Ԫ�أ�ƶBa��Sr��P��Ti Ԫ�صȣ���ʾ���͵�KCG ��( �߼ظƼ���) ������������������ɽ�󻨸���( POG) ��Ϊ�ҽ���ϳ��򡣸û����������ʯU--Pb ����ֵ�ֱ�Ϊ207 ± 2 Ma��197 ± 1 Ma������������—��٪���������ܰ�ʾ��Ϻ�Ľᾧ����ʱ�䣬���γɻ������������ǰ��ͻ��������ײ�ԽӺ����չ�����йء�

Porphyritic monzonitic granites were widely exposed in Nancha--Jinshantun area of Yichun��Heilongjiang�� The rock body occurred as batholiths with porphyry shape��and the rocks were flesh pink medium-coarse porphyritic monzonitic granite�� Phenocrysts consisted of potash feldspar and quartz and the matrix was composed of potash feldspar��plagioclase��quartz��biotite and a few amphibole locally�� The content of SiO2 was 69. 58% �� 75. 96%��alkaline was rich with Na₂O + K₂O of 7. 22% �� 8. 45% ��K₂O/Na₂O = 1. 07 �� 1. 43 ( σ = 1. 58 �� 2. 47) ��belonging to calc-alkaline granite�� The ΣREE was 178. 68 × 10^-6 �� 464. 75 × 10 ^-6��( La /Yb) N = 11. 6 �� 20. 22 with obvious LREE /HREE differentiation and negative Eu anomaly ( δEu = 0. 17 �� 0. 34) �� Trace elements were relatively rich in Rb��Th��U��Nd��La��Pr��and poor in Ba��Sr��P��Ti��indicating typical high-K calc-alkaline ( KCG-types) granite and post-orogenic ( POG) granite in characteristics��and formed with magma mixing origin�� The age of granites were 207 ± 2 Ma and 197 ± 1 Ma��belonging to Late Triassic and Early Jurassic��indicating magma crystallization duration after mixing�� The formation environment was ralated to the extension fuction after the continental collision between Siberia plate and North China plate��