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7871889 
Journal Article 
Catastrophic ocean acidification at the Triassic-Jurassic boundary 
Hautmann, M; Benton, MJ; Tomasovych, A 
2008 
1 
Neues Jahrbuch fuer Geologie und Palaeontologie. Abhandlungen
ISSN: 0077-7749 
249 
1 
119-127 
WOS:000258186700009 
Palaeobotanical and geochemical evidence indicate a sudden rise in atmospheric carbon dioxide (CO2) across the Triassic-Jurassic boundary, probably reflecting the combined effect of extensive volcanic degassing and thermal dissociation of marine gas hydrates. 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 biocalcification. These findings strengthen current concerns that ocean acidification from industrial CO2 release threatens biotopes that are dominated by such organisms, in particular tropical reef systems. 
ocean acidification; biomineralization; skeletal mineralogy; mass extinction; Triassic; Jurassic