Multiple phases of carbon cycle disturbance from large igneous province formation at the Triassic-Jurassic transition
Multiple phases of carbon cycle disturbance from large igneous province formation at the Triassic-Jurassic transition
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三叠纪-侏罗纪过渡时期大型火成岩省形成的碳循环扰动的多期阶段
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发表时间：
2011
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通讯作者：
Wolfram M Kürschner
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作者：
M. Ruhl;Wolfram M Kürschner
三叠纪末期大灭绝（英语：End-Triassic mass extinction）201.4 Ma）与一个主要的碳循环扰动相吻合，这是基于δ 13 C TOC（总有机碳）记录的0.55 ‰−6‰的负偏移。这两个事件直接与大西洋中部岩浆区（CAMP）的大规模玄武岩火山活动的开始相吻合。然而，来自西特提斯洋（奥地利）和日耳曼盆地（英国和德国）的有机碳同位素数据表明，在CAMP爆发之前，全球碳循环的早期中断。海洋和大陆δ 13 C TOC记录中的2‰−3‰的雷氏晚期前兆负偏移与δ 13 C叶数据中的负扰动相匹配，表明雷氏大气13 C亏损的多次事件。侵入岩脉和岩床系统，CAMP喷发火山活动之前，可能已经释放了3000-7000 Gt的同位素轻碳，作为地下富含有机质的地层中的产热甲烷。这可能导致了三叠纪末大气二氧化碳浓度的增加，并在CAMP地区爆发性火山活动实际开始之前降低了生态系统的稳定性。我们提出了一个模型，确定了三个阶段的全球地球化学循环的干扰有关的形成这个大火成岩省。
The end-Triassic mass extinction (ca. 201.4 Ma) coincided with a major carbon cycle perturbation, based on an ∼5‰−6‰ negative excursion in δ 13 C TOC (total organic carbon) records. Both events coincided directly with the onset of massive flood basalt volcanism in the Central Atlantic Magmatic Province (CAMP). Organic carbon isotope data from the western Tethys Ocean (Austria) and the Germanic basin (UK and Germany), however, demonstrate earlier disruption of the global carbon cycle, preceding CAMP eruptions. A 2‰−3‰ late Rhaetian precursor negative excursion in marine and continental δ 13 C TOC records is matched by a negative perturbation in δ 13 C leaf data, suggesting multiple events of Rhaetian atmospheric 13 C depletion. Intruding dike and sill systems, preceding CAMP eruptive volcanic activity, may have released ∼3000–7000 Gt of isotopically light carbon as thermogenic methane from subsurface organic-rich strata. This possibly caused an end-Triassic atmospheric p CO 2 increase and reduced ecosystem stability before the actual onset of eruptive volcanic activity in the CAMP region. We present a model that identifies three phases of disturbances in global biogeochemical cycles related to the formation of this large igneous province.