Are Interpretations of Ancient Marine Temperatures Constrained by the Presence of Ancient Marine Organisms?

  1. E.T. Sundquist and
  2. W.S. Broecker
  1. James W. Valentine

Published Online: 18 MAR 2013

DOI: 10.1029/GM032p0623

The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present

The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present

How to Cite

Valentine, J. W. (1985) Are Interpretations of Ancient Marine Temperatures Constrained by the Presence of Ancient Marine Organisms?, in The Carbon Cycle and Atmospheric CO: Natural Variations Archean to Present (eds E.T. Sundquist and W.S. Broecker), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM032p0623

Author Information

  1. Department of Geological Sciences, University of California, Santa Barbara, California 93106

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1985

ISBN Information

Print ISBN: 9780875900605

Online ISBN: 9781118664322

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Keywords:

  • Carbon cycle (Biogeochemistry)—Congresses;
  • Atmospheric carbon dioxide—Congresses;
  • Geological time—Congresses;
  • Paleothermometry—Congresses;
  • Geology, Stratigraphic—Congresses

Summary

The thermal tolerances of most organisms are probably not selected per se but arise from molecular structures selected for their kinetic properties—for capacity rather than resistance adaptations. Organisms contain molecules which display activities at temperatures far beyond any encountered in life. A few prokaryotes can tolerate boiling water; prokaryotic phototrophs live to about 73°C, eukaryotes to about 62°C, eukaryotic phototrophs to about 56°C, and metazoans to about 50°C; all groups are represented at temperatures near freezing. Living marine metazoans are adapted to today's temperatures. If late Precambrian marine temperatures were at, say, 50°C or so, we probably could not tell it from fossil evidence.