[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Ocean Acidification and the Permian and Triassic Extinctions
Asteroid impacts are not the only possible cause for the Permian
and Triassic-Jurassic extinctions. Some recent papers on one
1. Saunders, A., and M. Reichow, 2009, The Siberian Traps
and the End-Permian mass extinction: a critical review.
Chinese Science Bulletin. vol. 54, no. 1, pp. 20-37.
âCompromise of the carbon sequestration systems (by
curtailment of photosynthesis, destruction of biomass,
and warming and acidification of the oceans) probably
led to rapid atmospheric CO2 build-up, warming, and
shallow-water anoxia, leading ultimately to mass extinction.â
2. Knoll, A. H., R. K. Bambach, J. L. Payne, S. Prussa and
Woodward W. Fischer, 2007, Paleophysiology and
end-Permian mass extinction. Earth and Planetary
Science Letters. vol. 256, no. 3-4, pp. 295-313.
âGlobal warming, anoxia, and toxic sulfide probably all
contributed to end-Permian mass mortality, but
hypercapnia (physiological effects of elevated PCO2)
best accounts for the selective survival of marine
3. Hautmann, M., 2004, Effect of End-Triassic CO2 maximum
on carbonate sedimentation and marine mass extinction.
Facies. vol. 50, pp. 257â261.
âBesides the frequently cited climatic effect of enhanced
carbon dioxide, lowering the saturation state of sea water
with respect to calcium carbonate was an additional driving
force of the end-Triassic mass extinction, which chiefly
affected organisms with thick aragonitic or high-magnesium
calcitic skeletons. Replacement of aragonite by calcite, as
found in the shells of epifaunal bivalves, was an evolutionary
response to this condition.â
4. Hautmann, M., M., J. Benton, and A. Tomasovych, 2008,
Catastrophic ocean acidification at the TriassicâJurassic
boundary. Neues Jahrbuch fÃr Geologie und PalÃontologie
Abhandlungen. vol. 249, pp. 119â127.
"Using carbon isotopes as a geochemical marker, we found
that the onset of the CO2 emissions coincided with an
interruption of carbonate sedimentation in palaeogeographically
distant regions, suggesting that hydrolysis of CO2 led to
a short but substantial decrease of seawater pH that
slowed down or inhibited precipitation of calcium
carbonate minerals. The cessation of carbonate sedimentation
correlates with a major marine extinction event, which
especially affected organisms with aragonitic or high-Mg
calcitic skeletons and little physiological control of
5. Ryan, D., and D. Lehrann, 2009, Petrographic evaluation of
a Permian-Triassic erosion surface and implications for
causes of the end-Permian mass extinction. Geological Society
of America Abstracts with Programs, Vol 41, No. 4, p. 17
âour results favor genesis as a submarine dissolution
surface resulting from ocean acidification during the
6. Veron, J. E. N., 2008, Mass extinctions and ocean acidification:
biological constraints on geological dilemmas. Coral Reefs.
vol. 27, no. 3., pp. 459-472.
7. Zhuravlev, A. Y.,* and R. A. Wood, 2009, Controls on
carbonate skeletal mineralogy: Global CO2 evolution and
mass extinctions. Geology. vol. 37, no. 12, pp. 1123-1126.
âMass extinction events, many of which may be caused by
rapid global changes in temperature and/or pCO2, represent
major intervals of turnover.â