Timing and tempo of the Great Oxidation Event

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

The first significant buildup in atmospheric oxygen, the Great Oxidation Event (GOE), began in the early Paleoproterozoic in association with global glaciations and continued until the end of the Lomagundi carbon isotope excursion ca. 2,060 Ma. The exact timing of and relationships among these events are debated because of poor age constraints and contradictory stratigraphic correlations. Here, we show that the first Paleoproterozoic global glaciation and the onset of the GOE occurred between ca. 2,460 and 2,426 Ma, ∼100 My earlier than previously estimated, based on an age of 2,426 ± 3 Ma for Ongeluk Formation magmatism from the Kaapvaal Craton of southern Africa. This age helps define a key paleomagnetic pole that positions the Kaapvaal Craton at equatorial latitudes of 11° ± 6° at this time. Furthermore, the rise of atmospheric oxygen was not monotonic, but was instead characterized by oscillations, which together with climatic instabilities may have continued over the next ∼200 My until ≤2,250-2,240 Ma. Ongeluk Formation volcanism at ca. 2,426 Ma was part of a large igneous province (LIP) and represents a waning stage in the emplacement of several temporally discrete LIPs across a large low-latitude continental landmass. These LIPs played critical, albeit complex, roles in the rise of oxygen and in both initiating and terminating global glaciations. This series of events invites comparison with the Neoproterozoic oxygen increase and Sturtian Snowball Earth glaciation, which accompanied emplacement of LIPs across supercontinent Rodinia, also positioned at low latitude.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • Tomsk State University
  • Geological Survey of Canada
  • Naturhistoriska riksmuseet
  • University of Johannesburg
  • University of California, Riverside
  • University of Wyoming
  • Lund University
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Geokemi
  • Geologi

Nyckelord

Originalspråkengelska
Sidor (från-till)1811-1816
Antal sidor6
TidskriftProceedings of the National Academy of Sciences of the United States of America
Volym114
Utgivningsnummer8
StatusPublished - 2017 feb 21
PublikationskategoriForskning
Peer review utfördJa

Relaterad forskningsoutput

Ashley Gumsley, 2017 sep, (Submitted) Lund: Lund University, Faculty of Science, Department of Geology, Lithosphere and Biosphere Science. 130 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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