HR: 12:05h
AN: PP42A-07    [Abstracts]
TI: Discovery of a Cretaceous Scleractinian Coral with a Calcitic Skeleton
AU: Stolarski, J
EM: stolacy@twarda.pan.pl
AF: Institute of Paleobiology, Polish Academy of Sciences Twarda 51/55, Warsaw, PL-00-818, Poland
AU: * Meibom, A
EM: meibom@mnhn.fr
AF: Laboratoire d'Etude de la Matiere Extraterrestre, Muséum National d'Histoire Naturelle 61 rue Buffon, Paris, 74005, France
AU: Przenioslo, R
AF: Institute of Experimental Physics, University of Warsaw Hoza 69, Warsaw, PL-00-681, Poland
AU: Mazur, M
EM: mmazur@chem.uw.edu.pl
AF: Department of Chemistry, University of Warsaw Pasteura 1, Warsaw, PL-02-093, Poland
AB: It has been generally thought that scleractinian corals form purely aragonitic skeletons. We show that a well- preserved fossil coral, Coelosmilia sp. from the Upper Cretaceous (ca. 70 Ma), has preserved skeletal structural features identical to those observed in present day scleractinians. However, the skeleton of Coelosmilia sp. is entirely calcitic. Its fine-scale structure and chemistry indicate that the calcite is primary and did not from via diagenetic alteration of aragonite. This result implies that corals, like other groups of marine, calcium carbonate- producing organisms, can form skeletons of different carbonate polymorphs. Implications for coral biomineralization and evolution will be discussed.
DE: 0419 Biomineralization
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 4916 Corals (4220)
DE: 4924 Geochemical tracers
DE: 4954 Sea surface temperature
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting