�Ժ����˲����Ͽ���ϵţƺ����̼�����ҽ����˸߾��ȵ�̼����ͬλ�ط�����΢��Ԫ�زⶨ��̼ͬλ���ݻ������о�������ţƺ���涸ɽ�������Ӱ���²�����2 ��̼ͬλ�ظ�Ư�ƺ�3 ��������̼ͬλ����Ư�ơ���Ư�Ʒֱ�λ�ڶ�ɽ����ײ�( EN1) �Ͷ�ɽ�����в�( EN2) ��δ13C ֵ�ֱ𽵵͵��� 3. 6‰���� 2‰����Ư�Ʒֱ�λ�ڶ�ɽ�����²�( EP1) ���ϲ�( EP2) �Լ���ɽ����͵�Ӱ����ߴ�( EP3) ��δ13C �ֱ�������6. 7‰��7. 1‰��8. 2‰��ţƺ���氣�Ͽ���ϵδ13C ���ݻ����ƿ�����걳б��Ե���Ͽ���ϵ̼ͬλ���ݻ����ƶԱȣ���������������̼ͬλ�ػ�ѧ�ز�ѧ�ڰ��Ͽ���ϵ���ֺͶԱ��о�����Ҫ���塣

The authors analyzed the C and O isotopes and determined the trace elements from the carbonate rocks of Eidacaran in Niuping section of Yangtze Gorges��Hubei Province�� The C isotope evolvement trend showed two negative and three positive δ13 C excursions in Doushantuo Formation and Dengying Formation of the Niuping section�� The negative δ13C excursions located at the lowermost of Doushantuo Formaiton ( EN1) with a nadir at �� 3. 6‰��and the middle Doushantuo Formation ( EN2) with a nadir at �� 2‰�� The positive δ13C excursions located at lower Doushantuo Formaiton ( EP1) ��upper Doushantuo Formaiton ( EP2) and the boundary of Doushantuo Formaiton and Dengying Formation ( EP2) ��while the δ13 C increared to 6. 7‰��7. 1‰ and 8. 2‰��respectively�� The results indicate that the carbon isotopic chemostratigraphy in Niuping section can be campared with Huangling anticline��which is useful for regional correlation of the Ediacaran system in South China��