A Jurassic negative carbon isotope excursion (CIE), co‐evolved with Toarcian Oceanic Anoxic Event (OAE) at ~183 Ma, is suggested to be linked to a global carbon‐cycle perturbation and is well documented for Toarcian terrestrial fossil woods and marine sediments around the globe. A theoretically coupled δ¹³C_carb‐δ¹³C_org pattern due to such dubbed global carbon‐cycle event from the negative CIE in Dotternhausen Toarcian stratigraphic profile (southwest Germany) is unexpectedly disturbed by two‐step δ¹³C_carb‐δ¹³C_org decoupling in which the last step, upper in the stratigraphic order, is of higher magnitude. However, the trigger(s) for these sudden decoupling disturbances are still poorly constrained. Here, connecting new carbon and oxygen isotope data with documentary lipid biomarkers shows that the global carbon cycle during the Toarcian OAE was disturbed by enhanced green sulfur bacteria (GSB) metabolisms and early diagenesis at local scales. The first step δ¹³C_carb‐δ¹³C_org decoupling was induced in the initial stage of the GSB bloom. The second step of much larger δ¹³C_carb‐δ¹³C_org decoupling arising from a GSB prosperity was, however, exaggerated by early diagenesis through the respiration of sulfate‐reducing bacteria (SRB). Paleo‐geographically distinct localities of the Tethys region show contrasting decoupled δ¹³C_carb‐δ¹³C_org patterns, which implies that the second‐order carbon‐cycle perturbations have pervasively and independently impacted the global carbon event during the Toarcian OAE.

中文翻译：

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局部碳循环扰动的证据叠加在Toarcian碳同位素漂移上。

侏罗纪负碳同位素偏移（CIE）与〜183 Ma的Toarcian海洋缺氧事件（OAE）共同发展，被认为与全球碳循环扰动有关，并且对于Toarcian陆地化石和海洋沉积物有很好的记录在全球范围内。甲理论上耦合δ ¹³ Ç_{碳水化合物}-δ ¹³ Ç_组织由于从在多特尔恩豪森托尔阶地层剖面（西南德国）被意外地通过两步δ扰乱了负CIE这样配成全球碳周期事件图案¹³ Ç_{碳水化合物}-δ ¹³ Ç_组织解耦，其中最后一步，即地层顺序较高，幅度更大。然而，用于这些突然的去耦干扰的触发器仍然没有被很好地约束。在这里，将新的碳和氧同位素数据与文献中的脂质生物标记物联系起来表明，Toarcian OAE期间的全球碳循环受到绿色硫细菌（GSB）代谢增强和局部规模早期成岩作用的干扰。第一步δ ¹³ Ç_{碳水化合物}-δ ¹³ Ç_有机解耦在GSB开花的初始阶段诱导。的大得多的第二步骤中δ ¹³ C ^_{碳水化合物}-δ ¹³ Ç_有机然而，由于硫酸盐还原细菌（SRB）的呼吸作用，早期成岩作用加剧了由GSB繁荣引起的脱钩。古地理上不同的区域特提斯显示对比地方去耦δ ¹³ Ç_{碳水化合物}-δ ¹³ Ç_有机图案，这意味着所述二阶碳周期扰动已经普遍地且独立地影响了托尔阶OAE期间全球碳事件。