轨道强迫
地质学
古生物学
相
古气候学
拉丁语
构造盆地
进动
气候学
气候变化
海洋学
冰期
物理
天文
作者
Runjian Chu,Huaichun Wu,Qiang Fang,Wentao Huang,Dongyang Liu,Rixiang Zhu,Shihong Zhang,Tianshui Yang,Chengshan Wang
标识
DOI:10.1016/j.palaeo.2023.111763
摘要
Orbital forcing is a fundamental driver of Earth surface systems. The understanding of feedback responses to orbital forcing remains limited, with one of the most distinguishing features being its inherent nonlinearity. In this paper, we present geological evidence demonstrating nonlinearity during the greenhouse climate state, as exemplified by the Middle Triassic lacustrine-delta succession of the Ordos Basin in China. By combining the radio-isotopic and astronomical timescale, it suggests that lacustrine black shale facies were developed during early Ladinian hyperthermal episode, while deltaic facies were developed before and after the hyperthermal episode. The lacustrine redox cycles exhibit dominant precession cycles with a period of ∼20 kyr, whereas these precession cycles tend to be covered by the eccentricity and obliquity cycles with periods of ∼100 kyr and ∼ 33 kyr respectively in the deltaic detrital-input cycles. The diverse manifestations of orbital cycles in various environments can be explained by the nonlinear feedbacks. It is proposed that feedback mechanisms result from the combination effects of direct and indirect hyperthermal events, which are respectively manifested by the climatic processes (pCO2 level) and sedimentary processes. Sedimentary processes can enhance the influence of eccentricity through smoothing and memory effects, as supported by statistical analysis. The variations in atmospheric pCO2 may also contribute to the feedback of eccentricity and obliquity cycles through climate threshold and intertropical convergence zone, as supported by paleoclimate simulation and land-ocean correlations.
科研通智能强力驱动
Strongly Powered by AbleSci AI