CONODONTS AND TRACE ELEMENTS FROM THE PERMIAN-TRIASSIC BOUNDARY IN THE DINWOODY AND WOODSIDE FORMATIONS, DRY GULCH, SALT LAKE CITY

The purpose of this research is to identify the Permian-Triassic boundary located along the Wasatch front in Utah using geochemical analysis and conodont microfossil identification. Currently, there are very few studies of the boundary within the United States. The Permian-Triassic boundary is of interest because of the large mass-extinction event that occurred during that time. Geochemical analysis could provide insight into global conditions around this event. For our study, two sets of ten samples were collected from the Permian Park City and Lower Triassic Dinwoody/Woodside formations in Dry Gulch, Ft. Douglas Quadrangle, Utah. The first set of samples were prepared for inductively coupled plasma mass spectrometry (ICP-MS) analysis. By measuring the changes in mercury, nickel, and zinc levels along the boundary section and comparing them, the boundary can be identified. The second set of ten samples were processed and the conodonts separated by density. Thus far, specimens of the conodont genus Hindeodus have been recovered. Hindeodus parvus marks the base of the Triassic, allowing the refining of the contact between Permian and Triassic formations in this area. In a previous set of samples, Ellisonia sp. was found to be the most common, being present in 7 of 9 samples that contained conodonts. Ellisonia defines the uppermost Permian. Due to the widespread nature of conodonts, Hindeodus and Ellisonia together can be used to define the Permian-Triassic boundary in this area. The results of our study add clarity to the Permian-Triassic paleogeography in this area using known biostratigraphic markers and confirm use of the trace element composition as an independent marker for the Permian-Triassic boundary in Dry Gulch.