Neoproterozoic ice ages, boron isotopes, and ocean acidification: Implications for a snowball Earth

Simone A. Kasemann, Tony Prave, Anthony E. Fallick, Chris Hawkesworth, Karl-Heinz Hoffmann

Research output: Contribution to journalArticlepeer-review

43 Citations (Scopus)

Abstract

The Neoproterozoic Earth underwent at least two severe glaciations, each extending to low paleomagnetic latitudes and punctuating warmer climates. The two widespread older and younger Cryogenian glacial deposits in Namibia are directly overlain by cap carbonates deposited under inferred periods of high atmospheric carbon dioxide concentrations. Oceanic uptake of carbon dioxide decreases ocean pH; here we present a record of Cryogenian interglacial ocean pH, based on boron ( B) isotopes in marine carbonates. Our data suggest a largely constant ocean pH and no critically elevated pCO(2) throughout the older postglacial and interglacial periods. In contrast, a marked ocean acidification event marks the younger deglaciation period and is compatible with elevated postglacial pCO(2) concentration. Our data are consistent with the presence of two panglacial climate states in the Cryogenian, but indicate that each had its own distinct environmental conditions.

Original languageEnglish
Pages (from-to)775-778
Number of pages4
JournalGeology
Volume38
Issue number9
DOIs
Publication statusPublished - Sept 2010

Keywords

  • CARBON
  • CHEMISTRY
  • CONSTRAINTS
  • GLACIATION
  • TRANSITION
  • CALCIUM
  • NAMIBIA
  • PH

Fingerprint

Dive into the research topics of 'Neoproterozoic ice ages, boron isotopes, and ocean acidification: Implications for a snowball Earth'. Together they form a unique fingerprint.

Cite this