中国科学院南京地质古生物研究所王博团队近日揭示了侏罗纪对混乱的火星-地球偏心率周期的限制与火山诱发的詹金斯事件有关。这一研究成果发表在2025年6月30日出版的《美国科学院院刊》上。
太阳系引力相互作用嵌入了地球的气候记录中，提供了一种绕过混沌施加的6000万年限制的方法。目前，火星-地球轨道近日点频率的拍频周期为240万年，对混沌扩散特别敏感，可能变化超过一百万年。早中生代（252至145 Ma）地层对这一旋回提供了一些限制，有证据表明，大部分溶液空间从210 Ma的180万年摆动到190 Ma的250万年，再回到180 Ma的160万年。然而，只有180万年的旋回得到了地质年代学数据的证实，160万年的周期存在争议。
研究组表明，来自湖泊古高纬度三工河组（中国西北部准噶尔盆地）的陆地植物主导的稳定碳同位素比值（δ13Corg）的变化揭示了至少三个以183 Ma为中心的160万火星-地球周期，追踪了地球可交换碳库中的大气CO2同位素组成。此外，中期旋回包括著名的詹金斯事件，由卡鲁-费拉尔大火成岩省（LIP）的二氧化碳变暖驱动的唇瓣科针叶树向极地迁移来表达。
然而，该数据并不支持同位素轻碳的主要LIP触发输入，而是支持通过变暖和生态系统变化对局部过程的CO2放大。尽管需要额外的独立地质年代学支持，但三工河数据有助于为过滤轨道解、收紧初始条件和测试引力模型提供经验约束，并显示外部周期过程如何与构造事件卡鲁-费拉尔LIP相互作用。
附：英文原文
Title: Jurassic constraints on the chaotic Mars–Earth eccentricity cycle linked to the volcanically induced Jenkyns event
Author: Fang, Yanan, Olsen, Paul E., Sha, Jingeng, Whiteside, Jessica H., Guan, Chengguo, Ikeda, Masayuki, Li, Sha, Zheng, Daran, Zhang, Haichun, Wang, Bo
Issue&Volume: 2025-6-30
Abstract: Solar system gravitational interactions are embedded in Earth’s record of climate, providing a way to bypass the 60 Myr limit imposed by chaos. Presently with a 2.4 Myr period, the Mars–Earth beat cycle of orbital perihelion frequencies is particularly sensitive to chaotic diffusion, potentially varying by more than a million years. Early Mesozoic (252 to 145 Ma) strata provide some constraints on this cycle, with evidence of a swing through most of the solution space from 1.8 Myr at 210 Ma to 2.5 Myr at 190 Ma and back to 1.6 Myr at 180 Ma. However, only the 1.8 Myr cycle is corroborated by geochronologic data and the 1.6 Myr period is disputed. Here, we show that variations in land-plant-dominated stable carbon isotopic ratios (δ13Corg) from the lacustrine, paleo-high-latitude Sangonghe Formation (Junggar Basin, northwestern China), reveal at least three 1.6 Myr Mars–Earth beat cycles centered at 183 Ma, tracking atmospheric CO2 isotopic composition in Earth’s exchangeable carbon reservoirs. Furthermore, the middle cycle includes the famous Jenkyns Event, expressed here by poleward migration of cheirolepidaceous conifers driven by CO2 warming from the Karoo-Ferrar large igneous province (LIP). Our data do not, however, support major, LIP-triggered input of isotopically light carbon and instead support CO2 amplification of local processes via warming and ecosystem change. Although requiring additional independent geochronological support, Sangonghe data help provide empirical constraints for filtering orbital solutions, tightening initial conditions, and testing gravitational models, as well as showing how extrinsic cyclical processes interact with a tectonic event, the Karoo-Ferrar LIP.
DOI: 10.1073/pnas.2419902122
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2419902122