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Geoscience ›› 2019, Vol. 33 ›› Issue (04): 831-840.DOI: 10.19657/j.geoscience.1000-8527.2019.04.14

• Petroleum Geology • Previous Articles     Next Articles

Depositional Models and Differences of Lacustrine Carbonate Rocks: Comparison Between Qikou Sag and Biyang Sag

YANG Youxing(), GAO Yongjin, ZHANG Junfeng, ZHOU Xingui, ZHANG Jinhu, BAI Zhongkai, HAN Miao   

  1. Oil & Gas Survey, China Geology Survey, Beijing 100083, China
  • Online:2019-08-20 Published:2019-09-05

Abstract:

Based on core logging and spore and pollen analyses, comparison between the depositional models of the Qikou and Biyang sags was made and the major controlling factors were determined. The results show that the two sags contain clear differences in rock types, locations, scales and facies. The sedimentary area of lacustrine facies is over 2000 km2, which is distributed in the southwestern gentle slope area. It is featured by its large distribution area, small thickness, diverse rock and sedimentary facies and long deposition cycle. Carbonate rocks in the Biyang sag are mainly distributed in the central part of the depression, and are featured by small distribution area, large thickness, single sedimentary facies and short deposition cycle. The ancient landforms, openness of water body and climate conditions are likely the major causes for these differences. Factors such as salinity, temperature, biological groups and lacustrine levels also contributed substantially to these differences.

Key words: Qikou sag, Biyang sag, lacustrine carbonates, depositional model, controlling factor

CLC Number: