Provenance analysis of the lower member of Xingouzui Formation of Paleogene System in Mawangmiao Area of Qianjiang Sag

According to the distribution of heavy mineral percentage, features of clastic constituent of sand rocks, diplog traits, variation of palaeophyte distribution, provenance directions of Mawangmiao area was analyzed in this paper, and the result demonstrated that Mawangmiao area was influenced by two different provenances of northeast Hanchuan and northwest Hanshui. Based on the aforesaid research, combined with the features of sand content distribution and depositional environment, the study detailedly depicted different incidence of the two different provenances of every oil groups and considered the lower member of Xingouzui Formation in Mawangmiao area was mainly influenced by the northeast provenance, and the cross influenced area of the two different provenances convergenced on Ma 10 to Ma 39 well area. In the depositional era of Ⅲ oil group, the study area was minorly influenced by the northwest provenance. In the depositional era of Ⅱ oil group, the influence of the northeast provenance aggrandized than earlier phases and the influence of the northwest provenance had no further change. In the depositional era of Ⅰoil groups, the northeast provenance was still the major provenance but its influence faded down and the influence of the northwest provenance aggrandize than earlier phases.