Sr/Ca Ratio of Skeletal Aragonites from the Recent Marine Biota at Palau and from Fossil Gastropods
- Creators
- Lowenstam, Heinz A.
- Others:
- Craig, H.
- Miller, S. L.
- Wasserburg, G. J.
Abstract
The Sr/Ca ratios were determined from skeletal aragonites of the marine biota and sea water from Palau, South Pacific, where the temperature and Sr/Ca ratio of the waters are constant throughout the year. The Sr/Ca ratios of the aragonites from all groups of organisms except those of the higher Mollusca are similar or slightly higher than those in sea water. In samples from all phyla with high Sr/Ca ratios, the crystal chemistry is considered the primary control of the Sr/Ca ratios from their skeletal aragonites, whereas physiologic control by the organisms is considered as a second order effect. In agreement with data in the literature, the Sr/Ca ratios from the skeletal aragonites of the more advanced Mollusca were found to be low and indicate strong discrimination against Sr relative to Ca in the carbonate as compared to sea water, and this is related to physiologic control by the organisms. The measured Sr/Ca ratios from aragonitic shells of fossil gastropods from Cretaceous and Pennsylvanian deposits are shown to be higher the older the fossils. The increase in Sr/Ca ratios in the gastropod shells with increase in geologic age is toward the Sr/Ca ratio in present day sea water. It is suggested that this reflects biochemical evolutionary changes of increased discrimination by the gastropod against Sr relative to Ca from the late Paleozoic to the present.
Additional Information
© 1964 North-Holland Publishing Company. Contribution No. 1170, Division of Geological Sciences, California Institute of Technology. The writer is indebted to Dr. R. Owen at Koror, Palau, for making available laboratory space for preparing the collections of the recent samples from that area. Drs. W.E. Ham, N.F. Sohl, and Ch. Sumerson contributed most of the fossil samples to this study. I am grateful to Dr. K. Hatai for furnishing the temperature records from Palau. Sample preparations and X-ray determinations were made by J. Kiger and Mrs. M. Dekkers; spectrochemical determinations of Sr were made by Mrs. E. Bingham. Research was supported by PRF grant #34061 from the American Chemical Society, Petroleum Research Fund.Additional details
- Eprint ID
- 63948
- Resolver ID
- CaltechAUTHORS:20160125-154206535
- 34061
- American Chemical Society Petroleum Research Fund
- Created
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2016-01-26Created from EPrint's datestamp field
- Updated
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2019-10-03Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological Sciences
- Other Numbering System Identifier
- 1170