eprintid: 10195666 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/19/56/66 datestamp: 2024-08-13 10:56:06 lastmod: 2024-08-13 10:56:06 status_changed: 2024-08-13 10:56:06 type: article metadata_visibility: show sword_depositor: 699 creators_name: Zhang, K creators_name: Shields, GA creators_name: Zhou, Y creators_name: Strauss, H creators_name: Struck, U creators_name: Jensen, S title: The basal Cambrian carbon isotope excursion revealed in the Central Iberian Zone, Spain ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F57 keywords: Ediacaran, Cambrian, Carbon isotopes, Nitrogen isotopes note: © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). abstract: The causes of early metazoan diversification during the Ediacaran-Cambrian transition interval are controversial, partly because the global correlation of the Ediacaran-Cambrian boundary remains problematic due to a lack of unambiguous stratigraphic markers. Here we report geochemical data from two fossiliferous sections (Majada de Andaluz and Vía Verde) that straddle the Ediacaran-Cambrian interval in the Central Iberian Zone, Spain. Carbon isotope chemostratigraphy reveals a rise to a low positive δ13Ccarb plateau at the base of the Majada section, which is associated with the first appearance of Cloudina and a pristine Sr isotope value of 0.708512, suggesting that the lower Villarta Formation correlates with the terminal Ediacaran strata in China and Namibia. A prominent negative δ13Ccarb excursion is also revealed from the lower member of the Villarta Formation at Majada, likely corresponding to the global basal Cambrian carbon isotope excursion (BACE). Nitrogen isotope data from the correlative Vía Verde section reveal a similar trend to that found in coeval strata of South China, and indicate a change from predominantly anaerobic to aerobic nitrogen cycling in Central Iberia. By correlating sections in which both the BACE excursion and Treptichnus pedum are recognized, it appears that T. pedum is exclusively found above the BACE, which postdates the last appearance of Cloudina and a negative δ13Ccarb plateau. Further studies of sections with both fossil and isotopic control will help to constrain the timing and causation of Ediacaran-Cambrian bioradiations as well as their relationship to global carbon cycle perturbations. date: 2024-09-01 date_type: published publisher: Elsevier BV official_url: https://doi.org/10.1016/j.precamres.2024.107526 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2303974 doi: 10.1016/j.precamres.2024.107526 lyricists_name: Shields, Graham lyricists_id: GASHI56 actors_name: Shields, Graham actors_id: GASHI56 actors_role: owner full_text_status: public publication: Precambrian Research volume: 411 article_number: 107526 issn: 0301-9268 citation: Zhang, K; Shields, GA; Zhou, Y; Strauss, H; Struck, U; Jensen, S; (2024) The basal Cambrian carbon isotope excursion revealed in the Central Iberian Zone, Spain. Precambrian Research , 411 , Article 107526. 10.1016/j.precamres.2024.107526 <https://doi.org/10.1016/j.precamres.2024.107526>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10195666/1/Zhang%20et%20al%20%282024%29%20Ed-C%20boundary%20in%20Spain.pdf