The Upper Pennsylvanian Hushpuckney "Core" Black Shale Member from the Swope Formation in Kansas: Rhenium - Osmium Isotope Systematics, and the Highly Siderophile Elements.

Abstract

This thesis presents Rhenium - Osmium (Re-Os) systematics and Highly Siderophile Element (HSE) data from the (otherwise) geochemically and stratigraphically well studied Hushpuckney black shale from the Swope Formation in Kansas. Rhenium concentrations and the Re/Os ratios have a large spread that surpasses all published work on Re-Os. While the Re-Os data show significant scatter, the slope gives the expected age of 306 Ma. I use HSE's and Mo to consider geological processes that might have influenced the Re-Os systematics. The chondrite normalized HSE patterns are remarkably similar to that of seawater and supports the interpretation that the Midcontinent Seaway had an unrestricted opening to the open sea. Based on a comparison of the chondrite normalized HSE patterns to other sulfides, as well as a comparison of Mo and Re, the Hushpuckney black shale samples are most consistent with a mix of hydrogenous Re and molybdenite.