��м������ɷ���Դ�����컷�������챳����Դ����ʯ����������ء�ͨ��������������ˮȪ��ɰ����Ʒ����ɰ����м�����ɷ�ͳ�ơ�����ѧ��������м�ʯLA--ICP --MS U--Pb ���ѧ����Դ����������ȷ����ˮȪ��ɰ��Ϊ��ʯ��мɰ�ң���Դ�����챳����ҪΪ��½��������������Դ����Ϊ�и��͵�������ˮȪ��ɰ�������������м�ʯ����Ϊ338 ± 3 Ma��������ֵ������ˮȪ���γɵ�ʱ��Ϊ��ʯ̿�������������ڵ�Τ�ܽ׻�֮��903 �� 1 676 Ma �ķ�ɢԪ�Ž��ʯ����͡� 780 Ma ��Ԫ�Ŵ��ʯ�����ֵ�����ܷ�ӳ���ɹ�΢������������Ϣ���� 500 Ma �͡� 380 Ma �������ֵָʾԴ�����ܾ����˶����ҽ��¼�: �� 500 Ma ���ҽ��ʯ��Դ�������Զ���������˰��ؿ�պ���صĺ���ɽ�����ң� �� 500 Ma �ı����ʯ�������Ա��ʻ��ף� �� 380 Ma ����Դ���ܷ�ӳ�������—�˰��ؿ������۵ؿ�����������������ʼ��ײƴ���������¸�������һ����������—��ʯ̿�����ҽ�����

Through the study of sandstone detrital component statistics��geochemical characteristic and detrital zircon LA--ICP--MS U--Pb dating of Hongshuiquan Formation sandstone in Yimin area��the authors confirm that the sandstone lithology of Hongshuiquan Formation is feldspar lithic sandstone in category��the tectonic setting of source area is continental island arc in Paleo environment��and the provenance is divided island arc in type�� The youngestdating of detrital zircon of Hongshuiquan Formation sandstone is 338 ± 3 Ma��which indicates the formation as the Visean of Middle Mississippian in Carboniferous in age even younger�� The Proterozoic zircon aged in 903 �� 1 676 Ma and the New Proterozoic zircon peak may aged in �� 780 Ma��reflect the basement age of southern Mongolian micro-block�� The peak age of �� 500 Ma and �� 380 Ma indicate that the material source area probably went through multi-staged magma events��in which the �� 500 Ma indicates the source might come from post-orogenic granites concern with the closure of Erguna and Xing'an blocks��while the �� 380 Ma may reflect that the Erguna --Xing'an block started to collide and collage with Songnen block at Late Devonian��at least��and formed a magmatic arc during the Late Devonian --Early Carboniferous��