Abstract

The Utica shale is an extensive gas shale play within the Appalachian Basin, expanding from Quebec through New York, into Pennsylvania, West Virginia, and Ohio. Currently a target for gas exploration, it is also the source rock for much of the Paleozoic reservoirs throughout the Basin. Handheld X–ray fluorescence (HH–XRF) was performed on core 6430 from Washington County, Ohio, containing the Utica shale, Point Pleasant Formation, and Lexington Limestone, focusing on elemental changes in concentrations with depth using selected major and trace elements. Elemental cross plots were generated to establish relationships between elements to determine sediment source. Positive correlation of Si, Fe, Zr, and K with Al indicate the association with terrigenous-sourced clay minerals. Al concentrations within the Lexington Limestone, Point Pleasant Formation, and Utica shale samples range between 1.0 and 10.0 wt.%, compared to the average shale with a value of 8.8 wt.% (Wedepohl, 1971). Overall, the Utica shale, Point Pleasant Formation, and Lexington Limestone are enriched in Ca compared to average shale by an order of magnitude. In depth analysis regarding the existence of bottom water anoxia environment was not performed based on the depletion of redox trace elements. Finally, 9 chemofacies were identified using hierarchical cluster analysis (HCA). In conclusion, there are noticeable changes from the Point Pleasant Formation into the Utica shale in core 6430, representing changes in sediment provenance and productivity.