Fossil echinoderms as monitor of the Mg/Ca ratio of phanerozoic oceans Journal Article uri icon

DCO ID 11121/5434-8988-5035-1786-CC

in language

  • eng

year of publication

  • 2002


  • Opinion has long been divided as to whether the Mg/Ca ratio of seawater remained constant during the Phanerozoic or underwent substantial secular change. Existing empirical evidence for the Mg/Ca of ancient seawater provides a poorly resolved and often controversial signal. Echinoderm fossils that have retained their bulk original chemistry, despite micrometer-scale changes, preserve a record of seawater Mg/Ca and confirm that major changes in Mg/Ca occurred during the Phanerozoic. Echinoderms from the Cambrian and from the Carboniferous to the Triassic indicate a seawater Mg/Ca of 3.3, whereas echinoderms from the Jurassic to the Cretaceous indicate a Mg/Ca of 1.4. The present seawater Mg/Ca is 5.


  • 298


  • 5596