Response of larger benthic foraminifera to the Paleocene-Eocene thermal maximum and the position of the Paleocene/Eocene boundary in the Tethyan shallow benthic zones: Evidence from south Tibet

Abstract

Research Article| August 01, 2018 Response of larger benthic foraminifera to the Paleocene-Eocene thermal maximum and the position of the Paleocene/Eocene boundary in the Tethyan shallow benthic zones: Evidence from south Tibet Qinghai Zhang; Qinghai Zhang † 1Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, and CAS Centre for Excellence in Tibetan Plateau Earth Sciences, Lincui Road 16-3, 100101 Beijing, China2Department of Geosciences, University of Bremen, Klagenfurter Straße 4, 28359 Bremen, Germany †zhang@itpcas.ac.cn Search for other works by this author on: GSW Google Scholar Helmut Willems; Helmut Willems 2Department of Geosciences, University of Bremen, Klagenfurter Straße 4, 28359 Bremen, Germany3Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, East Beijing Road 39, 210008 Nanjing, China Search for other works by this author on: GSW Google Scholar Lin Ding; Lin Ding 1Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, and CAS Centre for Excellence in Tibetan Plateau Earth Sciences, Lincui Road 16-3, 100101 Beijing, China Search for other works by this author on: GSW Google Scholar Xiaoxia Xu Xiaoxia Xu 2Department of Geosciences, University of Bremen, Klagenfurter Straße 4, 28359 Bremen, Germany Search for other works by this author on: GSW Google Scholar GSA Bulletin (2019) 131 (1-2): 84–98. https://doi.org/10.1130/B31813.1 Article history received: 24 Mar 2017 rev-recd: 21 May 2018 accepted: 19 Jun 2018 first online: 01 Aug 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Qinghai Zhang, Helmut Willems, Lin Ding, Xiaoxia Xu; Response of larger benthic foraminifera to the Paleocene-Eocene thermal maximum and the position of the Paleocene/Eocene boundary in the Tethyan shallow benthic zones: Evidence from south Tibet. GSA Bulletin 2018;; 131 (1-2): 84–98. doi: https://doi.org/10.1130/B31813.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Paleocene-Eocene thermal maximum (PETM) is one of the most pronounced global warming events in the Cenozoic. This event was associated with a large negative carbon isotope excursion (CIE) and with major changes in the atmosphere, hydrosphere, and biosphere. However, how the larger benthic foraminifera (LBFs) in the shallow Tethyan Ocean responded to the PETM remains controversial. In this study, we investigate two shallow-marine, LBF-rich carbonate sections from south Tibet, aiming to locate the position of the Paleocene/Eocene (P/E) boundary in the Tethyan shallow benthic zones (SBZs) and to examine the response of the LBFs to the PETM. Carbon isotope compositions of bulk carbonate were measured to constrain the stratigraphic position of the CIE onset marking the P/E boundary in the sections, and the LBFs were studied in rock thin sections in order to assess their biostratigraphy and to construct the SBZs. The combination of the carbon isotope data and constructed SBZs shows that the P/E boundary is located within SBZ5, not at the SBZ4/SBZ5 transition as proposed in the Western Tethyan domain. At the P/E boundary, no evident compositional change in LBF assemblages can be observed. However, a major compositional change in LBF assemblages occurs in the CIE recovery, characterized by the sudden disappearance of Miscellanea, Ranikothalia, Setia, Orbitosiphon, and the initial dominance of porcellaneous-walled Alveolina and Orbitolites together with small miliolids and rotaliids. We tentatively speculate that this compositional change in LBF assemblages may be related to a eutrophication event, likely resulting from intensified continental weathering during the CIE recovery of the PETM. You do not currently have access to this article.