Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin

Abstract

Research Article| November 01, 2015 Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin Aitor Payros; Aitor Payros † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Search for other works by this author on: GSW Google Scholar Silvia Ortiz; Silvia Ortiz † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain2PetroStrat Ltd., Tan-y-Graig, Parc Caer Seion, Conwy, Wales LL32 8FA, UK †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Search for other works by this author on: GSW Google Scholar Isabel Millán; Isabel Millán † 3TNO Petroleum Geoscience, Princetonlaan 6, 3584 CB Utrecht, The Netherlands †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Search for other works by this author on: GSW Google Scholar Javier Arostegi; Javier Arostegi † 4Department of Mineralogy and Petrology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Search for other works by this author on: GSW Google Scholar Xabier Orue-Etxebarria; Xabier Orue-Etxebarria † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Search for other works by this author on: GSW Google Scholar Estibaliz Apellaniz Estibaliz Apellaniz † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Search for other works by this author on: GSW Google Scholar Author and Article Information Aitor Payros † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain Silvia Ortiz † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain2PetroStrat Ltd., Tan-y-Graig, Parc Caer Seion, Conwy, Wales LL32 8FA, UK Isabel Millán † 3TNO Petroleum Geoscience, Princetonlaan 6, 3584 CB Utrecht, The Netherlands Javier Arostegi † 4Department of Mineralogy and Petrology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain Xabier Orue-Etxebarria † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain Estibaliz Apellaniz † 1Department of Stratigraphy and Paleontology, Faculty of Science and Technology, University of the Basque Country (UVP/EHU), B° Sarriena s/n, 48940 Leioa, Spain †E-mails: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]. Publisher: Geological Society of America Received: 19 Jan 2015 Revision Received: 23 Mar 2015 Accepted: 04 May 2015 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2015 Geological Society of America GSA Bulletin (2015) 127 (11-12): 1632–1644. https://doi.org/10.1130/B31278.1 Article history Received: 19 Jan 2015 Revision Received: 23 Mar 2015 Accepted: 04 May 2015 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Aitor Payros, Silvia Ortiz, Isabel Millán, Javier Arostegi, Xabier Orue-Etxebarria, Estibaliz Apellaniz; Early Eocene climatic optimum: Environmental impact on the North Iberian continental margin. GSA Bulletin 2015;; 127 (11-12): 1632–1644. doi: https://doi.org/10.1130/B31278.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The early Eocene climatic optimum, which constituted the peak of the long-term early Cenozoic global warming, had a significant impact on the environmental evolution of terrestrial and oceanic areas. Surprisingly, however, its influence on continental margins is poorly known. New insights are provided from a sedimentological, stable isotope, mineralogical, and micropaleontological study of an 1100-m-thick Lower–Middle Eocene deep-marine succession that accumulated on the North Iberian continental margin. The early Eocene climatic optimum is represented by a 410-m-thick interval characterized by scarcity of hemipelagic limestones, abundance of dark marls, which record a reduction in calcium carbonate content and an increase in kaolinite, and the occurrence of conspicuous red layers with high siderite and pyrite content.Series of stratigraphically significant events frame the early Eocene climatic optimum. Based on this analysis, the environmental influence of the early Eocene climatic optimum started at 52.6 Ma and lasted ∼2.3 m.y. Its onset is marked by rapid drops in δ13C and δ18O, which record the addition of 13C-depleted carbon into the ocean-atmosphere system for 80 k.y. and a concomitant warming. A hotter climate and a perennial rainfall regime increased the supply of terrestrial clays, organic matter, and iron oxides into the sea. Eventually, these changes affected the deep-sea bottom 270 k.y. after the onset of the early Eocene climatic optimum, creating conditions in which opportunistic benthic foraminifera thrived, and leading to increased methanogenesis in the subsurface, which caused the formation of siderite. A subsequent gradual recovery culminated abruptly at 50.3 Ma with a global cooling episode, which is locally recorded by the accumulation of lowstand resedimentation deposits. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.