����ѡȡ�ƺ�������5 ��������ĵ�ZK1 ��ף���������������������ϸ���������������Ȳ��Ժ��п׳������������ZK1 �����Ȳ����Ĵ���ֲ����С�ͨ����������—��׼ƫ��ı仯�����ZK1 �׳������жԳ��������仯��Ϊ���е�������ֵķ�ΧΪ3. 75 �� 4 �� �ͣ� 10 ��������������ֺ�������ȱ仯�ij����������������Ȳ�������ֲ��������п׳����ϱ������ƺ�������ZK1 �׵ij����������¿ɷ�Ϊ4 ��: �� ( 0 �� 5. 14 m) Ϊ1904—1976 ����������ƽԭ����; �� ( 5. 14 �� 17. 41 m) Ϊ1855 ����������������ƽԭ����; �� ( 17. 41 �� 22. 6 m) Ϊ1855 ����ǰ��½�ܳ���; �� ( 22. 6 �� 24. 6 m) Ϊ��ƺ������

Detailed lithologic description��grain-size testing and foraminifer identification from the ZK1 of the five drilling cores in Yellow River delta have been done��with the analysis of their vertical distribution sequence�� The change of grain-size and standard deviation showed the sensitive grain-size population to sedimentary environment variation in ZK1 drilling core are 3. 75 �� 4 �� and �� 10 ���� The sedimentary environment of ZK1 in Yellow River delta can be divided into 4 stages through the analysis of sensitive grain-size population contents varied in depth��vertical distribution characteristics of grain-size parameters and foraminifer informations�� The first stage ( 0 �� 5. 14 m) is upper delta plain deposition from 1904 to 1976; the second stage ( 5. 14 �� 17. 41 m) is lower delta plain deposition since 1855; the third stage ( 17. 41 �� 22. 6 m) is continental shelf deposition before 1855; and thefourth stage ( 22. 6 �� 24. 6 m) is tidal flat deposition��