Chemostratigraphy Across the Permian‐Triassic Boundary
Chemostratigraphy Across the Permian‐Triassic Boundary
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DOI：
10.1002/9781119382508.ch9
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发表时间：
2018-11
期刊：
影响因子：
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通讯作者：
Martin Schobben;F. Heuer;Melanie Tietje;A. Ghaderi;D. Korn;C. Korte;P. Wignall
中科院分区：
文献类型：
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作者：
Martin Schobben;F. Heuer;Melanie Tietje;A. Ghaderi;D. Korn;C. Korte;P. Wignall
一个主要的灭绝脉冲发生在牙形石定义的二叠纪-三叠纪边界之下。全球范围内越来越大的古生物学、沉积学和地球化学数据集的汇编通过解开时空模式进一步扩大了我们对这一事件的理解。强大的地层框架是这些全球汇编的一个组成部分。大量碳酸盐岩碳同位素记录是一种广泛使用且易于生成的地层工具;它可以取代生物地层学。然而，地层碳同位素模式的幅度和形状的不一致性也阻碍了不同地理位置的成功联系。在这项研究中，我们专注于各种石灰岩相的多组分性质。我们展示了如何采样策略可以适应，以检索材料从这个多组分系统，将最有可能代表长期模式的海洋溶解无机碳δ 13 C。通过获得多个随机选择的床内样本，我们发现床内δ 13 C变化的幅度在不同的岩性之间可能有所不同。然而，我们也注意到，最大的床内变化（超过0.5‰）并不对应于这种特定岩石的明显结构变化。地层内部变化并不总是追踪海洋溶解无机碳δ 13 C，可能会导致识别不明确的同位素地层标志物，这些标志物并不暗示全球相关信号。
A major extinction pulse occurred just below the conodont‐defined Permian‐Triassic boundary. Global‐scale compilations of increasingly larger paleontological, sedimentological, and geochemical datasets further amplify our understanding of this event by unraveling temporospatial patterns. Robust stratigraphic frameworks are an integral part of these worldwide compilations. Bulk carbonate rock carbon isotope records are a widely used, and easy‐to‐generate, stratigraphic tool; it can substitute for biostratigraphy. However, inconsistencies in the amplitude and shape of stratigraphic carbon isotope patterns have also hampered the successful linkages of different geographic locations. In this study, we focus on the multicomponent nature of various limestone facies. We show how sampling strategies can be adapted in order to retrieve material from this multicomponent system that will most likely represent secular patterns in marine dissolved inorganic carbon δ13C. By obtaining multiple and randomly chosen bed‐internal samples, we reveal that the magnitude of bed‐internal δ13C variations can differ between distinct lithologies. However, we also note that the largest within‐bed variations (in excess of 0.5‰) do not correspond to obvious textural variations for this specific rock. Bed‐internal variations do not always trace marine dissolved inorganic carbon δ13C and might cause identification of ambiguous isotope stratigraphic markers that do not allude to globally correlative signals.