CHEMOSTRATIGRAPHY OF THE ORDOVICIAN TRENTON AND UTICA GROUPS: A CONTINUUM OF FACIES RELATIONSHIPS BETWEEN CARBONATE SHELF, SLOPE, AND BASIN DEPOSITS IN CENTRAL MOHAWK VALLEY, NY

The cryptic nature of mudstone limits the use of common techniques such as lithologic description, stratal boundary identification, and thin section petrography to distinguish significant sedimentary packages and depositional structures. In recent years, the use of XRD (x-ray diffraction), XRF (x-ray fluorescence), SEM (scanning electron microscopy), stable and radiogenic isotopes, and other geochemical techniques have assisted in determining chronostratigraphic correlations, highlighting changes in sediment provenance and basin evolution, and identifying high quality pay zones in terms of oil and natural gas exploration. These techniques have been proven successful on core and drill cutting samples from many areas of unconventional exploration and production.

The main objective of this study is to determine whether these widely used tools and techniques, when applied to Ordovician Trenton Limestone and Utica Shale outcrop samples, reveal spatial and temporal variability of elemental composition and mineralogy. These trends may represent changes in depositional environment, and confirm or oppose previous stratigraphic correlations in the area. The banks of West Canada Creek and its tributaries in the Mohawk Valley of central New York State provide nearly complete outcrop exposures of Trenton Group and Utica Shale deposits to be analyzed in this study. I intend to compare results gathered from outcrop samples to those from nearby core to investigate the effects of outcrop weathering. However, working with outcrop samples has two distinct advantages over core samples, 1) they are more easily and cheaply obtained and 2) a more robust lithologic interpretation can be made providing context to geochemical analyses.