�����Ե¶ͷ����ػ����꾮���ش������ϣ��ۺ��о�ݺ�躣���ǰ���������������������������Ե Song Da �� 18 �������ز����С�166 ����ʯ��Ʒ�ܶȺ� 2 800 �״Ż��ʲ�������������ܶ�- - �Ż��ʽ���ͼ�棬Լ�����ڵ���������ش��쳣���ͣ�ͨ����½��ϵķ������Ƴ���ػ��׵���ͼ����ǰ��������ǰ��ϵ������ϵ—������ͳ�²���������ͳ�ϲ�—����ϵ��������㹹�ɣ������غ�Ӷ��ѳʱ�����ֲ����м��ϣ�Ϊǰ�𵩼���—�߼�������; �����£�����Ϊ�����������ң���Ϊ������dz�����ҡ����ҡ�

Combining basin margin outcrops with basement drilling and geophysical data��a comprehensive study is conducted on the basement characteristics of basement in Yinggehai Basin for pre- Cenozoic�� Based on the sequence stratigraphic data of 18 outcrop sections��density data of 166 rock samples��and 2 800 sets of magnetic susceptibility data collected from the Song Da zone at the northwestern margin of the basin��a density- magnetic sus- ceptibility crossplot is constructed�� These data additionally provide geological constraints for the interpretations of the seismic profiles and geophysical anomalies within the basin�� A basement geologic map is subsequently drafted with a combination of marine and terrestrial perspectives�� The pre- Cenozoic basement is composed of Presinian�� Cambrian- lower Upper Triassic�� and upper Upper Triassic- Cretaceous�� Spatially�� they distribute along the ��ed ��iv- er fault zone in a NW orientation�� Chronostratigraphically and lithologically��they are characterized by a gradual ag- ing trend from the middle to the two sides�� and by a lithologic pattern of Mesozoic sedimentary rocks at west and Pa- leozoic epi- metamorphic rocks at east��