Zhang Xiaohui, Zhao Zhongyuan. DEFINITION OF MILANKOVITCH CYCLES FOR YANGCHANG FORMATION OF THE UPPER TRIASSIC IN ORDOS BASIN[J]. 2002, 23(4): 372-375.DOI: 10.11743/ogg20020415.
Climate changes caused by orbital are widely recorded in sedimentary record and reflected by Gamma-ray logging data. The thickness range of stratigraphic cycles in Yangchang Formation is obtained through analyzing the Gamma-ray logging data of Shaan NO.15 in Ordos basin. The thickness range caused by eccentricity is 9.6-18.75m and the thickness range caused by obliquity of the earth's axis and climate precession is 1.18-6.82m.The sedimentation rate of various oil layers in Yangchang Formation ranges from 7.8 to 14.2cm/ka.