High‐resolution C‐isotope, TOC and biostratigraphic records of OAE 1a (Aptian) from an expanded hemipelagic cored succession, western Tethys : a new stratigraphic reference for global correlation and paleoenvironmental reconstruction
| Autor: | Helmut Weissert, Richard D. Pancost, Luis M. Nieto, Matías Reolid, María Luisa Quijano, P. A. Ruiz-Ortiz, Peter W. Skelton, Rafael Martínez-Rodríguez, José Miguel Molina, Ian Jarvis, Carmina López-Rodríguez, José Manuel Castro, Ginés A. de Gea, Roque Aguado |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Paleoceanography and Paleoclimatology Castro, J M, Ruiz-Ortiz, P A, de Gea, G A, Aguado, R, Jarvis, I, Weissert, H, Molina, J M, Nieto, L M, Pancost, R D, Quijano, M L, Reolid, M, Skelton, P W, López-Rodríguez, C & Martínez-Rodríguez, R 2021, ' High-Resolution C-isotope, TOC and Biostratigraphic Records of OAE1a (Aptian) from an Expanded Hemipelagic Cored Succession, Western Tethys : a New Stratigraphic Reference for Global Correlation and Paleoenvironmental Reconstruction ', Paleoceanography and Paleoclimatology, vol. 36, no. 3, e2020PA004004 . https://doi.org/10.1029/2020PA004004 |
| Popis: | 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. Fourteen 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 ultra-high-resolution scale (0.2–0.5 kyr spacing), revealing a succession of sharp δ13 Ccarb negative spikes, interpreted as the record of pulses in 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 δ13 Ccarb 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. |
| Databáze: | OpenAIRE |
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