GEOCHEMICAL APPROACHES TO THE STUDY OF LIFE AND DEATH OF DINOSAURS FROM THE EARLY CRETACEOUS CEDAR MOUNTAIN FORMATION, UTAH

Abstract

In this dissertation, geochemical analysis of fossil vertebrate remains are carried out to elucidate fossil diagenesis and for paleoenvironmental reconstructions. Rare earth elements (REE) are analyzed via laser ablation inductively coupled plasma mass spectrometry (ICP-MS) in order to determine REE distribution within a bone. Analysis indicates REE can vary significantly within a single bone and that thin-walled bones fossilized in vadose settings should not be analyzed via solution ICP-MS. Stable isotopic analysis of oxygen preserved in tooth enamel and scale ganoine is used to discriminate water reservoirs used by the taxa making up several faunal assemblages from the Cedar Mountain Formation. Based on the isotopic composition of calculated ingested/living water of theses taxa, it can be determined that the proximity of the Western Interior Seaway and the rise of the Sevier Mountains were the cause of isotopic variability and dominant control on regional climate during the Cedar Mountain Formation time.