Osmium-isotope evidence for volcanism, weathering, and ocean mixing during the early Aptian OAE 1a

Research Article| July 01, 2012 Osmium-isotope evidence for volcanism, weathering, and ocean mixing during the early Aptian OAE 1a Cinzia Bottini; Cinzia Bottini 1Dipartimento di Scienze della Terra "Ardito Desio", Università degli Studi di Milano, Via Mangiagalli 34, 20133 Milan, Italy2Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Anthony S. Cohen; Anthony S. Cohen 2Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Elisabetta Erba; Elisabetta Erba 1Dipartimento di Scienze della Terra "Ardito Desio", Università degli Studi di Milano, Via Mangiagalli 34, 20133 Milan, Italy Search for other works by this author on: GSW Google Scholar Hugh C. Jenkyns; Hugh C. Jenkyns 3Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK Search for other works by this author on: GSW Google Scholar Angela L. Coe Angela L. Coe 2Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Geology (2012) 40 (7): 583–586. https://doi.org/10.1130/G33140.1 Article history received: 20 Dec 2011 accepted: 27 Jan 2012 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Cinzia Bottini, Anthony S. Cohen, Elisabetta Erba, Hugh C. Jenkyns, Angela L. Coe; Osmium-isotope evidence for volcanism, weathering, and ocean mixing during the early Aptian OAE 1a. Geology 2012;; 40 (7): 583–586. doi: https://doi.org/10.1130/G33140.1 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 SocietyGeology Search Advanced Search Abstract The early Aptian Oceanic Anoxic Event (OAE 1a) resulted from an exceptional set of interactions between the geosphere, the biosphere, and the ocean-atmosphere system. We present new Re-Os data from two sites spanning OAE 1a in the Tethys and Pacific Oceans. The patterns of variation in the seawater Os-isotope composition from both sites are very similar, and together they constrain the timing and duration of continental weathering in relation to the large-scale volcanic activity of the Ontong Java Plateau. The dominant feature through the OAE is an interval of ∼880 k.y. when the Os-isotope composition of the global ocean was exceptionally unradiogenic, implicating unambiguously the Ontong Java Plateau as the trigger and sustaining mechanism for OAE 1a. A relatively short-lived (∼100 k.y.) Os-isotope excursion to radiogenic compositions in the Tethyan record is clearly linked to an abrupt perturbation to the global carbon cycle, and is fully consistent with the Pacific record. These highly distinctive features of seawater Os in contemporaneous samples from three high-resolution sections, two of which were very remote from the Ontong Java Plateau, indicate that ocean mixing at that time was very efficient. The results suggest that OAE 1a was also related to rapid global warming and elevated rates of silicate weathering both on the continents and in the oceans. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.