Conventional uranium series and S-R open system methods of age determination were applied to the dating of unrecrystallized fossil corals and molluscan shells. Two of the six corals have remained closed systems with respect to uranium and daughter isotopes 230Th and 231Pa; the other four coral samples were dated by the S-R model. Analyses of coexistent mollusk shells revealed complex migrational patterns of uranium, thorium, and protactinium in these samples. Three of the six shells yielded acceptable conventional U series or S-R model ages.