Archaeal lipid biomarker constraints on the Paleocene-Eocene carbon isotope excursion
Archaeal lipid biomarker constraints on the Paleocene-Eocene carbon isotope excursion
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DOI：
10.1038/s41467-019-12553-3
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发表时间：
2019-10-04
影响因子：
16.6
通讯作者：
Pearson, Ann
中科院分区：
文献类型：
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作者：
Elling, Felix J.;Gottschalk, Julia;Pearson, Ann
记录在陆地和海洋档案中的负碳同位素漂移反映了在古新世-始新世热峰期间大量碳排放到外生碳库中。然而，不同样本类型的碳同位素漂移估计存在差异，导致碳排放的来源、规模和时间存在很大的不确定性。在这里，我们发现海洋浮游古细菌的膜脂可靠地记录了古新世-始新世热峰期间的碳同位素漂移和表层海洋变暖。考古酚同位素组成的新记录将全球碳同位素漂移幅度限制在-4.0+/-0.4‰，与甲烷水合物解离产生的~gt；3000 pg C或涉及地热加热或沉积有机质氧化排放的>；4400pg C的排放一致。古考古酚同位素组成和海洋温度的提前漂移突出了古新世晚期碳循环对扰动的敏感性，并表明气候不稳定先于古新世-始新世最高温度。
A negative carbon isotope excursion recorded in terrestrial and marine archives reflects massive carbon emissions into the exogenic carbon reservoir during the Paleocene-Eocene Thermal Maximum. Yet, discrepancies in carbon isotope excursion estimates from different sample types lead to substantial uncertainties in the source, scale, and timing of carbon emissions. Here we show that membrane lipids of marine planktonic archaea reliably record both the carbon isotope excursion and surface ocean warming during the Paleocene-Eocene Thermal Maximum. Novel records of the isotopic composition of crenarchaeol constrain the global carbon isotope excursion magnitude to -4.0 +/- 0.4 parts per thousand, consistent with emission of >3000 Pg C from methane hydrate dissociation or >4400 Pg C for scenarios involving emissions from geothermal heating or oxidation of sedimentary organic matter. A pre-onset excursion in the isotopic composition of crenarchaeol and ocean temperature highlights the susceptibility of the late Paleocene carbon cycle to perturbations and suggests that climate instability preceded the Paleocene-Eocene Thermal Maximum.