Strontium corals

Thompson G, Livingston HD (1970) Strontium and uranium concentrations in aragonite precipitated by some modem corals. Earth Planet Sci Lett 8 439-442 ThurberDL (1962) Anomalous in Nature. J Geophys Res 67 4518-4520... 

Smith S.V., Buddemeier R.W., Redaije R.D. and Houck J.E. (1979) Strontium-calcium thermometry in coral skeletons. Science 204, 404-407. 

Weber J.N. (1973) Incorporation of strontium into reef coral skeletal carbonates. Geochim. Cosmochim. Acta 37, 2173-2190. 

Beck J. W., Edwards R. L., Ito E., Taylor E. W., Recy J., Rougerie F., Joannot P., and Henin C. (1992) Sea-surface temperature from coral skeletal strontium/calcium ratios. Science 257, 644—647. 

As subaerially exposed corals interact with meteoric waters, they are altered to calcite. This alteration results in a lost of strontium from the skeleton, and will obviously have strong effects on Sr/Ca paleothermometry. To avoid this problem, researchers routinely screen for the presence of calcite in fossil corals. A new study (McGregor and Gagan, 2003) demonstrates that local diagenesis can have marked affects on coral Sr/Ca, with a very large positive bias on... 

The author thanks A. Cohen for sharing her compilation of coral strontium cahbrations, and J. Cole, J. Clark, D. Schrag, and H. Spero for discussions. Some of this material is based upon work supported by the US National Science Foundation, more recently under grant OCE-0117886. 

Alibert C. and McCulloch M. T. (1997) Strontium/calcium ratios in modern porites corals from the Great Barrier Reef as a proxy for sea surface temperature cahbration of the thermometer and monitoring of ENSO. Paleoceanography 12(3), 345-363. 

Rathburn A. E. and Deckker P. D. (1997) Magnesium and strontium compositions of recent benthic foraminifera from the Coral Sea, Australia and Prydz Bay, Antarctica. Mar. Micropaleontol. 32, 231-248. 

Allison, N., Finch, A. A., Newville, M. Sutton, S. R. 20051>. Strontium in coral aragonite 3. Sr coordination and geochemistry in relation to skeletal architecture. Geochimica et Cosmochimica Acta, 69, 3801-3811. 

Strontium is quite common in seawater. Some organisms use strontium sulfate as a skeletal material. Strontium is added to the water in aquariums, as the decorative stony corals need it. Strontium has no function in the human body. (It is the most abundant element in the human body without a known function there.) Nor is barium essential for Hfe indeed it is toxic. The symptoms of barium poisoning are colic, diarrhoea, vomiting and paralysis. The content of barium in food plants is as a rule low (part per million levels) but there is an exception Brazil nuts may contain as much as 1% barium. The metabolism is stimulated by barium, but to such a high degree that the heart begins to beat erratically (ventricular fibrillation). Barium salts are thus toxic to humans, but the use of barium sulfate as an X-ray contrast medium is accepted because of its very low solubility. 

Le Cornec, E, and Correge,T. (1997). Determination of uranium to calcium and strontium to calcium ratios in corals by inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 12(9), 969. 

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