No causal link between terrestrial ecosystem change and methane release during the end-Triassic mass extinction
No causal link between terrestrial ecosystem change and methane release during the end-Triassic mass extinction
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DOI：
10.1130/g32928.1
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发表时间：
2012-06-01
期刊：
影响因子：
5.8
通讯作者：
Richoz, Sylvain
中科院分区：
文献类型：
--
作者：
Lindstrom, Sofie;van de Schootbrugge, Bas;Richoz, Sylvain
三叠纪末期大规模灭绝事件期间海洋生物和陆地生物群的深刻变化，以及与之相关的跨越三叠纪-侏罗纪界线(T-J，201.3 Ma)的连续碳循环扰动，主要归因于中大西洋岩浆省的火山排放和/或甲烷的注入。在这里，我们提出了一个新的扩展有机碳同位素记录，来自丹麦盆地T-J岩心界线序列，由高分辨率孢粉地层学测年，并辅之以海洋动物群记录。与英国的参考碳同位素和生物记录相关联，它提供了新的证据，表明陆地和海洋上的主要生物变化在最显著的碳同位素负漂移之前就开始了。如果涉及大规模的甲烷释放，它并没有触发三叠纪末期的大灭绝。相反，这种负的碳同位素漂移与陆地上植物恢复的开始是同时的，而海洋生态系统仍然受到干扰。陆地和海洋生态系统恢复之间的脱钩更有可能是由于长期的玄武岩火山活动释放了SO2和CO2，分别具有短期和长期影响。
Profound changes in both marine and terrestrial biota during the end-Triassic mass extinction event and associated successive carbon cycle perturbations across the Triassic-Jurassic boundary (T-J, 201.3 Ma) have primarily been attributed to volcanic emissions from the Central Atlantic Magmatic Province and/or injection of methane. Here we present a new extended organic carbon isotope record from a cored T-J boundary succession in the Danish Basin, dated by high-resolution palynostratigraphy and supplemented by a marine faunal record. Correlated with reference C-isotope and biotic records from the UK, it provides new evidence that the major biotic changes, both on land and in the oceans, commenced prior to the most prominent negative C-isotope excursion. If massive methane release was involved, it did not trigger the end-Triassic mass extinction. Instead, this negative C-isotope excursion is contemporaneous with the onset of floral recovery on land, whereas marine ecosystems remained perturbed. The decoupling between ecosystem recovery on land and in the sea is more likely explained by long-term flood basalt volcanism releasing both SO2 and CO2 with short- and long-term effects, respectively.