A high‐resolution carbonate C‐isotope stratigraphy for the Aptian is presented for the Cau core (Spain). The biostratigraphically calibrated C‐isotope stratigraphy of the core is used to refine the previously defined C‐isotope segments of the Aptian. Thirteen C‐isotope segments have been identified and correlated, and further subdivisions are presented. Correlation with other sections worldwide demonstrates the robustness of the C‐isotope stratigraphy of the Cau core. The studied succession includes a continuous record of the early Aptian Oceanic Anoxic Event (OAE 1a). Its onset has been studied at an ultrahigh‐resolution scale (0.2–0.5 kyr spacing), revealing a succession of sharp δ¹³C_carb negative spikes, interpreted as a record of pulses of volcanism and methane emissions. The largest spike was rapid (<10 kyr) and marks the base of OAE 1a, which occurs within a longer‐term falling δ¹³C_carb trend. The C‐isotope profile across OAE 1a perfectly records the negative (C3/Ap3), positive (C4/Ap4), steady (C5/Ap5), and positive (C6/Ap6) segments that were defined from Cismon (Italy) and subsequently identified worldwide. The Ap7 to Ap14 segments record a C‐isotope negative excursion, coupled with high TOC contents, probably related to regional paleogeography. The links with global environmental changes, episodes of widespread deposition of organic matter, and ultimately to major volcanic episodes are discussed. We propose the Cau core as a new reference section for the Aptian, and specifically for OAE 1a, based on its expanded and well‐preserved sedimentary, geochemical and biotic archives, which provide further insights into the environmental and biotic changes that occurred during this time interval.

中文翻译：

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西部特提斯扩展的半旋状有芯花序的高分辨率C-同位素，TOC和OAE 1a（Aptian）生物地层记录：全球相关性和古环境重建的新地层学参考

为Cau岩心（西班牙）提出了Aptian的高分辨率碳酸盐C同位素地层。岩心的生物地层校准C同位素地层用于完善Aptian先前定义的C同位素片段。现已鉴定出13个C同位素片段并进行了关联，并提出了进一步的细分方法。与世界其他地区的相关性证明了Cau岩心C同位素地层的稳健性。所研究的演替包括早期Aptian海洋缺氧事件（OAE 1a）的连续记录。其发病已经研究在超高分辨率标度（0.2-0.5 KYR间距），露出锋利的δ的连续¹³ Ç_{碳水化合物}负峰值，解释为火山和甲烷排放脉冲的记录。最大尖峰是快速的（<10 KYR）和标记OAE 1a的基础上，其中长期落入δ内发生¹³ Ç_{碳水化合物}趋势。跨OAE 1a的C同位素图谱完美记录了从Cismon（意大利）定义的负（C3 / Ap3），正（C4 / Ap4），稳定（C5 / Ap5）和正（C6 / Ap6）片段已在全球范围内确认。Ap7至Ap14段记录了C同位素负偏移，以及高TOC含量，这可能与区域古地理有关。讨论了与全球环境变化，有机物广泛分布的事件以及最终与主要火山事件的联系。我们建议将Cau岩心作为Aptian（尤其是OAE 1a）的新参考部分，基于其扩展且保存完好的沉积，地球化学和生物档案，这些文献可提供有关此期间发生的环境和生物变化的进一步见解间隔。