This is a multi-institutional proposal by Showers(N.C. State University) and Riggs(E. Carolina University) which was submitted with identical texts and was reviewed as one proposal. The PIs propose to extend the work of Riggs on depositional models for highly cyclic, Miocene phosphorite sediments on the North Carolina continental margin to include stable isotopic evidence of diagenetic changes within the phosphorites. Once samples with diagenetic overprints have been identified, the remaining samples will be used to interpret a high-resolution paleoceanographic record of isotopic changes during the Miocene. This record will be combined with the rock-record of sealevel changes in order to examine the role of paleoclimate and sealevel on continental margin sedimentation.