Coupled evolution of temperature and carbonate chemistry during the Paleocene-Eocene; new trace element records from the low latitude Indian Ocean

James Barnet, Kate Littler, Dustin Harper, Leah J LeVay, Kirsty Edgar, Michael Henehan, Tali L. Babila, Clemens Ullmann, Melanie J. Leng, Dick Kroon, James Zachos

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)
111 Downloads (Pure)

Abstract

The early Paleogene represents the most recent interval in Earth's history characterized by global greenhouse warmth on multi-million year timescales, yet our understanding of long-term climate and carbon cycle evolution in the low latitudes, and in particular the Indian Ocean, remains very poorly constrained. Here we present the first long-term sub-eccentricity-resolution stable isotope (δ 13C and δ 18O) and trace element (Mg/Ca and B/Ca) records spanning the late Paleocene–early Eocene (∼58–53 Ma) across a surface–deep hydrographic reconstruction of the northern Indian Ocean, resolving late Paleocene 405-kyr paced cyclicity and a portion of the PETM recovery. Our new records reveal a long-term warming of ∼4–5 °C at all depths in the water column, with absolute surface ocean temperatures and magnitudes of warming comparable to the low latitude Pacific. As a result of warming, we observe a long-term increase in δ 18O sw of the mixed layer, implying an increase in net evaporation. We also observe a collapse in the temperature gradient between mixed layer- and thermocline-dwelling species from ∼57–54 Ma, potentially due to either the development of a more homogeneous water column with a thicker mixed layer, or depth migration of the Morozovella in response to warming. Synchronous warming at both low and high latitudes, along with decreasing B/Ca ratios in planktic foraminifera indicating a decrease in ocean pH and/or increasing dissolved inorganic carbon, suggest that global climate was forced by rising atmospheric CO 2 concentrations during this time.

Original languageEnglish
Article number116414
JournalEarth and Planetary Science Letters
Volume545
Early online date18 Jun 2020
DOIs
Publication statusPublished - 1 Sep 2020

Keywords

  • Indian Ocean
  • Paleocene-Eocene Thermal Maximum
  • Paleogene
  • paleoceanography
  • paleoclimate
  • trace elements

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'Coupled evolution of temperature and carbonate chemistry during the Paleocene-Eocene; new trace element records from the low latitude Indian Ocean'. Together they form a unique fingerprint.

Cite this