1. A Synthesis of Late Oligocene through Miocene Deep Sea Temperatures as Inferred from Foraminiferal Mg/Ca Ratios

  1. Maria Mutti2,
  2. Werner Piller3 and
  3. Christian Betzler4
  1. Katharina Billups and
  2. Kathleen Scheiderich

Published Online: 3 APR 2012

DOI: 10.1002/9781118398364.ch1

Carbonate Systems during the Oligocene-Miocene Climatic Transition

Carbonate Systems during the Oligocene-Miocene Climatic Transition

How to Cite

Billups, K. and Scheiderich, K. (2012) A Synthesis of Late Oligocene through Miocene Deep Sea Temperatures as Inferred from Foraminiferal Mg/Ca Ratios, in Carbonate Systems during the Oligocene-Miocene Climatic Transition (eds M. Mutti, W. Piller and C. Betzler), Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781118398364.ch1

Editor Information

  1. 2

    Institut für Erd- und Umweltwissenschaften Universität Potsdam, Postfach 60 15 53 D-14415 Potsdam, Germany

  2. 3

    Institute for Earth Sciences (Geology & Paleontology) University of Graz, Heinrichstrasse 26, A-8010 Graz, Austria

  3. 4

    Geologisch-Palaeontologisches Institut, Bundesstr. 55, D-20146 Hamburg, Germany

Author Information

  1. School of Marine Science and Policy, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA

Publication History

  1. Published Online: 3 APR 2012
  2. Published Print: 5 APR 2012

Book Series:

  1. Special Publication Number 42 of the International Association of Sedimentologists

Book Series Editors:

  1. Ian Jarvis5,6

Series Editor Information

  1. 5

    School of Geography, Geology and the Environment Centre for Earth and Environmental Science Research, Kingston University London, UK

  2. 6

    Penrhyn Road, Kingston upon Thames KT1 2EE, UK

ISBN Information

Print ISBN: 9781444337914

Online ISBN: 9781118398364

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Keywords:

  • Oligocene, Miocene;
  • palaeotemperatures;
  • palaeoclimate, palaeoceanography;
  • foraminifera

Summary

Published benthic foraminiferal Mg/Ca records have been compiled that span the latest Oligocene through Miocene, including new data for the South Atlantic. This synthesis, the first such of Mg/Ca data, necessitates consideration of uncertainties and limitations and provides a general perspective on the evolution of deep-sea temperatures over this period. Published Mg/Ca records show temperature patterns through the Miocene that are consistent with those first synthesized by Kennett (1985) utilizing isotope and other data. Accordingly, the early Miocene was an interval of relative warmth culminating in a climatic optimum at ∼16Ma that was characterized by the warmest (Mg-derived) temperatures of the past 20 million years. After the climatic optimum, palaeotemperatures dropped by 3–4 °C during the second major advance of Antarctic ice between ∼15Ma and 13 Ma. For the late Miocene, between 11 and 8.5 Ma, a distinct increase in benthic foraminiferal Mg/Ca ratios at two Atlantic sites provides evidence for deep to intermediate water circulation changes. Thereafter, temperatures close to modern are recorded at all sites. Assuming constant seawater Mg/Ca ratios through time, it can be concluded that the early Miocene climate was generally warmer than today and that by the late Miocene temperatures approached modern values.