For the Middle Permian-Lower Triassic marine carbonate rocks in Chuanxi area, the author analyzed the carbon and oxygen isotope three cross-sectional data and calculated the Z value and the ancient temperature in combination with sedimentary facies and paleo organisms to systematically study the carbon and oxygen isotopic characteristics of carbonate rocks in the region and the paleo environment. The results show that the value of δ¹³C varies from -3.90‰ to 2.80‰ in the study area, mainly concentrated between -2.80‰ and 2.80‰, and -0.04‰ on average; The value of δ¹⁸O varies from - 9.70‰ to -1.80‰, mainly concentrated between -8‰ and -4‰, and -6.60‰ on average. Through calculation and analysis of the Z value and the paleo temperature it can be seen that Middle Permian-Lower Triassic in Chuanxi area was basically in the marine environment with seawater temperature between 8.8 and 68.4℃ and the main distribution range 16 to 33℃. The study area basically belonged to the warm or hot tropical climate and experienced three major cycles of sea level changes: Qixia period to the Maokou period, Wujiaping middle period to Changxin period, and Feixianguan period to Jialingjiang period.

Chuanxi area  /  Middle Permian-Lower Triassic  /  carbon and oxygen isotopes  /  paleo environment