近日，南京大学张飞飞团队报道了大陆风化增强触发晚古生代温室到冰窖气候转变的锂同位素证据。相关论文发表在2026年3月17日出版的《国家科学评论》杂志上。

早密西西比亚纪（约359–347 Ma）温室气候向冰室气候的转型，标志着晚古生代冰期（LPIA）的可能开端，其成因至今仍是地球气候史未解之谜。该转型与杜内中期碳同位素漂移事件（TICE）同期发生。现有假说认为，这一时期增强的大陆硅酸盐风化作用通过固存二氧化碳、促进营养盐输入并提升海洋生产力，最终触发TICE正漂移。然而增强大陆风化的直接证据长期缺失。

研究组通过两个碳酸盐岩剖面的锂同位素（δ⁷Li）数据，揭示TICE期间δ⁷Li值下降约12‰。将δ⁷Li记录与碳循环模型（GEOCLIM和COPSE）耦合分析表明，TICE事件期间硅酸盐化学风化速率提升约30%，伴随风化强度减弱——这一变化可能源于构造隆升或植被演化，最终使大气pCO₂降低约1000 ppm。该发现为增强风化作用、CO₂下降与LPIA启动之间的因果关系提供了证据，阐明了晚古生代气候变化的关键机制。

附：英文原文

Title: Lithium Isotope Evidence for Enhanced Continental Weathering Triggering the Late Paleozoic Greenhouse-to-Icehouse Climate Transition

Author: Zhang, Feifei, Wei, Guang-Yi, Maffre, Pierre, Li, Ziheng, Zhou, Jianlin, Pohl, Alexandre, Bo Lin, Yi-, Elrick, Maya, Cheng, Keyi, von Strandmann, Philip A E Pogge, Shen, Shu-zhong

Issue&Volume: 2026-03-17

Abstract: The causes of the transition from a greenhouse to an icehouse climate during the Early Mississippian (~359–347 Ma), marking the possible onset of the Late Paleozoic Ice Age (LPIA), remain an outstanding puzzle in Earth’s climate history. This transition coincides with the mid-Tournaisian carbon isotope excursion (TICE). It is hypothesized that intensified continental silicate weathering during this period sequestered CO, boosted nutrients, and increased marine productivity, causing the positive TICE. However, direct evidence for enhanced continental weathering has been lacking. We present lithium isotope (δLi) data from two carbonate sections showing a ~12‰ decline during TICE. Integrating δLi with carbon cycle models (GEOCLIM and COPSE) suggests silicate chemical weathering rates increased ~30% with declines in weathering intensity during the TICE event, likely due to uplift or vegetation, ultimately reducing atmospheric pCO by ~1000 ppm. This provides evidence linking enhanced weathering, CO drawdown, and the onset of the LPIA, shedding light on a key aspect of late Paleozoic climate change.

DOI: 10.1093/nsr/nwag168

Source: https://dx.doi.org/10.1093/nsr/nwag168