近日，北京大学李明松团队报道了早三叠世古气候和沉积的轨道强迫：来自华北大禹林剖面的启示。2026年8月4日出版的《中国科学：地球科学》杂志发表了这项成果。

早三叠世在二叠纪-三叠纪大灭绝之后经历了剧烈的气候和环境扰动。然而，陆地系统对轨道强迫气候变化的响应仍缺乏充分约束，这主要是由于高分辨率年代学框架的可用性有限。

研究组对中国华北大羽林剖面（孙家沟组-刘家沟组-和尚沟组）陆相地层序列的自然伽马测井数据和X射线荧光元素数据的第一主成分进行了时间序列分析。通过将古气候代用指标序列调谐至405 kyr长偏心率周期，建立了浮动天文时间标尺。结合经旋回校准的磁性地层学，为地层解释和剖面间对比提供了坚实的年代学框架。将沉积噪声模型应用于调谐后的古气候代用指标序列，研究组识别出沉积噪声增强的区间，这些区间与主要相转变相对应，表明气候不稳定性可能影响了沉积体制的变化。

该研究进一步揭示了早三叠世沉积噪声序列中呈现的1.2 Myr斜率调制周期，该周期对应于火星-地球的s₄−s₃长期共振。这一调制在低纬度陆相序列中的探测，突显了长期轨道强迫对陆地水文气候和沉积稳定性的影响。此外，该结果为早三叠世陆地旋回地层学提供了新的参考框架，并为完善未来天文解决方案和盆地间对比提供了地质约束。

附：英文原文

Title: Orbital forcing of paleoclimate and sedimentation in the Early Triassic: Insights from the Dayulin Section, North China

Author: anonymous

Issue&Volume: 2026-08-04

Abstract: The Early Triassic witnessed dramatic climatic and environmental perturbations following the Permian-Triassic mass extinction. However, terrestrial responses to orbitally forced climate change remain poorly constrained, largely due to the limited availability of high-resolution chronological frameworks. Here, we apply time series analysis of natural gamma-ray logs and the first principal component of X-ray fluorescence elemental data from a terrestrial succession at the Dayulin section in North China (Sunjiagou-Liujiagou-Heshanggou formations). This study establishes a floating astronomical time scale by tuning the paleoclimate proxy series to the 405kyr long-eccentricity cycle. Integrated with cycle-calibrated magnetostratigraphy, it provides a robust chronological framework for stratigraphic interpretation and inter-section correlation. Applying the sedimentary noise model to the tuned paleoclimate proxy series, we identify intervals of enhanced sedimentary noise that align with major facies transitions, suggesting that climatic instability may have influenced changes in the depositional regime. This study further reveals a 1.2Myr obliquity modulation cycle corresponding to the Mars-Earth s4s3 secular resonance during the Early Triassic, expressed within the sedimentary noise series. The detection of this modulation in a low-latitude continental succession highlights the influence of long-term orbital forcing on terrestrial hydroclimate and depositional stability. Moreover, our results provide a new reference framework for Early Triassic terrestrial astrochronology and a geological constraint for refining future astronomical solutions and inter-basin correlations.

DOI: 10.1007/s11430-026-1953-3

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-026-1953-3