ABSTRACT

The fission track method has been used to determine the uranium concentrations of fractured, internal valve and external valve surfaces of present-day pelecypod shells. Results of this initial study indicate that the fission track method may be able to obtain uranium concentration values which are useful in carbonate depositional environment studies involving mulluscan shell material.

A distinct variation in concentrations of uranium was found on different shell surfaces of the same organism. Large variations in concentrations were found for different molluskan shells with a definite correlation between magnitude of contained uranium and environment. External valve surfaces consistently have higher concentration values than internal valve surfaces, which is believed to be related to the organic coating preserved on the external surface of the recent shells.

A variety of future studies are suggested based upon results of the initial experiments. These problems can be grouped under two headings: 1) samplings similar to the initial study and 2) similar type study of fossil carbonate material.