RARE EARTH ELEMENT (REE) ANALYSIS OF VERTEBRATE FOSSILS FROM THE UPPER CRETACEOUS CARBONATE MARINE FORMATIONS OF WESTERN AND CENTRAL ALABAMA, USA: TAPHONOMIC AND PALEOENVIRONMENTAL IMPLICATIONS

Abstract

Rare earth element (REE) analysis of vertebrate fossils has previously been used to answer a number of stratigraphic, taphonomic, and paleoenvironmental questions concerning the depositional environments of Cretaceous siliciclastic marine and freshwater formations. In this study, vertebrate fossils from Upper Cretaceous formations of Alabama were analyzed to determine if REE analyses could be equally effective at resolving taphonomic and paleoenvironmental questions in marine carbonate strata. Results indicate that these fossils possess unique REE signatures, although they are not as distinctive as those of siliciclastic formations. REE data can also be used, with limitations, for stratigraphic assignment of vertebrate fossils as well as indicating relative paleobathymetry. Furthermore, differences in REE signatures between certain taxonomic groups and REE concentrations in different osteological material are observed. In conclusion, findings herein indicate that REE analysis of vertebrate fossils from carbonate deposits can be effective for paleoenvironmental and regional paleogeographic studies.