doi:10.16186/j.cnki.1673-9787.2023100013

Received:2023-10-16

Revised:2023-12-04

Online Date:2024-01-25

Triassic climate and its evolution characteristics in Jiyuan Area，South of North China Plate：Evidence from paleosol geochemistry（Online）

YANG Wentao, FENG Wanying, ZHANG Hongyu, WANG Min

School of Resources and Environment，Henan Polytechnic University，Jiaozuo 454000，Henan，China

Abstract: Objective The Triassic was in a period of rapid fluctuation of greenhouse climate，and the paleo⁃sol recorded abundant paleoclimate information. To study the climate change process from extreme to me⁃dium greenhouse，Methods the Triassic paleosoils in the Jiyuan area were selected for major chemical composition.The mean annual precipitation and mean annual temperature were estimated to reconstruct the pa⁃ leoclimate and its evolution.Results The results show that 15 layers of paleosol（including calcareous soil，organic soil and gleyed soil） are identified in the Triassic strata in Jiyuan area.The mean annual precipitationin the Jiyuan area during the Triassic was 447~1 557 mm/a，and the mean annual temperature was 11~23 ℃.In the Early Triassic，the mean annual precipitation was 447~896 mm，and elevated precipitation oc⁃curred in the late time. The mean annual temperature was 16~23 ℃ ，showing a downward trend. In theMiddle Triassic，the mean annual precipitation was 679~1 539 mm/a，showing an increasing trend.The meanannual temperature was 11~20 ℃，and the low value occurred in the middle stage.In the Late Triassic，themean annual precipitation was 575~1 557 mm/a，with lower values in the early and late stages，and high val⁃ues in the middle stage. Triassic climate fluctuation was relatively common in the south of North China.There was a relatively wet period in the Early Triassic，an overall wetting trend occurred in the Middle Triassic，and the Late Triassic also had dry periods.Conclusion These data can provide reference for the Triassic climate evolution.

Key words:Triassic;climate evolution;geochemistry;Jiyuan Area

CLC：P59;P534.51;P532