Middle Eocene-Lower Oligocene calcareous nannofossil biostratigraphy and paleoceanographic implications from Site 711 (equatorial Indian Ocean)

Author(s)

Fioroni, Chiara ^[1] ; Villa, Giuliana ^[2] ; Persico, Davide ^[2] ; Jovane, Luigi ^[3]

Affiliation

^[1] Univ Modena & Reggio Emilia, Dipartimento Sci Chim & Geol, I-41125 Modena - Italy

^[2] Univ Parma, Dipartimento Fis & Sci Terra, I-43100 Parma - Italy

^[3] Univ Sao Paulo, Inst Oceanog, BR-05508120 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: MARINE MICROPALEONTOLOGY; v. 118, p. 50-62, JUN 2015.
• Web of Science Citations: 5

Abstract

Nannofossil data from ODP Site 711 (equatorial Indian Ocean) yield a set of consistent, reliable biohorizons that form the basis of a revised calcareous nannofossil biostratigraphy for the low-latitude Eocene-Oligocene. We discuss 31 biohorizons occurring over an 11 myr time interval which we correlate to previous magnetostratigraphic data. Calcareous nannofossils from the middle Eocene through the lower Oligocene of the studied section are characterized by moderately well preserved assemblages consisting largely of low latitude and cosmopolitan species. A significant nannofossil dissolution interval is evidenced at the middle Eocene Climatic Optimum (MECO). We document a significant increase in late Eocene nannoplankton exhibiting a eutrophic preference. Analysis of the assemblage suggests important changes in the equatorial oceanic regime just before the onset of the Eocene-Oligocene transition (EOT), that foreshadow the more dramatic climatic shift of the early Oligocene. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 11/22018-3 - Primary productivity in oceans studying magnetotactic bacteria in sediments
• Grantee: Luigi Jovane
• Support Opportunities: Research Program on Global Climate Change - Young Investigators