EAGER: Do Mass Extinctions Have Diagenetic Consequences? Investigating Unique Early Diagenesis at the Triassic-Jurassic Boundary

大灭绝有成岩后果吗？摘要三叠系—侏罗系边界独特的早期成岩作用研究[j] David J. bottjerco . pi: Frank A. corsettitiar .]成岩特征通常被认为是？二次特征吗?因为它们发生在沉积物被掩埋之后，大部分与地表条件隔绝。作为次要特征，它们在研究古代环境时通常被忽视。相比之下，pi最近的发现表明，在大灭绝时期，在海底或海底以下发生的成岩过程可能确实包含了以前未被注意到的大灭绝原因的线索。pi是否发现了独特的成岩特征？碳酸钙扇层？与三叠系-侏罗系（T-J）界线有关，是？5大吗?不列颠哥伦比亚省东部的物种大灭绝结构和地球化学证据表明，碳酸钙层在海底下方迅速生长，很可能受到大灭绝时期海洋化学的影响。碳同位素分析结合质量平衡计算表明，早成岩层中可能存在碳酸盐的溶蚀作用，为碳酸钙的形成提供了来源，这可能表明在其形成过程中海洋酸化是一种潜在的灭绝机制。在这里，pi提出了一个新的概念，即大规模灭绝机制可能影响成岩领域，研究长期被忽视的成岩特征可能以以前未开发的方式阐明灭绝机制。有趣的是，一项文献检索在世界各地的其他T-J边界遗址发现了不寻常的碳酸盐成岩特征，但它们的性质和发生与灭绝有关尚不清楚。为了确定这些特征是否与灭绝有关，pi提出了一项初步研究，以调查在其他地方发现的不寻常的成岩阶段(例如，圣奥德里？英国的s湾；威尔士拉弗诺克角；和北爱尔兰的拉恩)，在他们新兴的与灭绝相关的成岩作用框架内。从多个地方发现的碳酸盐成岩特征确实与灭绝有关，这一发现将为随后对许多其他T-J遗址的全面研究提供动力，以开发一个新的窗口。早期成岩领域？在大灭绝的研究中。

Do Mass Extinctions Have Diagenetic Consequences? Investigating Unique Early Diagenesis at the Triassic-Jurassic BoundaryPI: David J. BottjerCo-PI: Frank A. CorsettiEAR-1017536ABSTRACT The geological process of diagenesis occurs when soft sediments are turned into hard rocks. Diagenetic features are commonly considered ?secondary features? because they occur after the sediments are buried, mostly isolated from surface conditions. As secondary features, they are usually overlooked when investigating ancient environments. In contrast, PIs recent discoveries suggest that diagenetic processes operating at or just below the seafloor during the time of a mass extinction may indeed hold previously unnoticed clues to the causes of mass extinctions. PIs have discovered unique diagenetic features?calcium carbonate fan layers?associated with the Triassic-Jurassic (T-J) boundary, one of the ?Big 5? mass extinctions, in eastern British Columbia. Textural and geochemical evidence suggests that the calcium carbonate layers grew immediately below the seafloor, likely influenced by ocean chemistry at the time of the mass extinction. Carbon isotopic analysis coupled with mass balance calculations suggest dissolution of preexisting carbonate likely provided the source of calcium carbonate for the early diagenetic layers, potentially indicating ocean acidification in their formation and as a potential extinction mechanism.Here, PIs propose the novel concept that mass extinction mechanisms could affect the diagenetic realm and that studying long-ignored diagenetic features might elucidate the extinction mechanisms in ways not previously exploited. Intriguingly, a literature search turned up unusual carbonate diagenetic features at other T-J boundary sites from around the world, but their nature and occurrence with respect to the extinction is unclear. To determine whether the features are relevant to the extinction, PIs propose a pilot study to investigate unusual diagenetic phases found elsewhere (e.g., St. Audrie?s Bay, England; Lavernock Point, Wales; and Larne, Northern Ireland) within their emerging framework of extinction-related diagenetic effects. The discovery that the carbonate diagenetic features from multiple localities are indeed relevant to the extinction will provide the impetus for a subsequent full-scale study of numerous other T-J sites to exploit a new window?the early diagenetic realm?in the study of mass extinctions.