PALEOENVIRONMENT AND PALEOCLIMATE RECONSTRUCTION OF A TETRAPOD FOSSIL BEARING LOCALITY IN TROUT RUN, NORTH-CENTRAL PENNSYLVANIA

The Late Devonian fossil locality of Trout Run North (TRN) in north-central Pennsylvania has previously yielded a fossil femur from a Whatcheerid-like tetrapod. To date, Devonian-age tetrapod fossils in Pennsylvania are restricted to this site and the approximately contemporaneous Red Hill fossil locality. The femur from TRN was previously discovered in a channel-lag deposit of a fluvial system dated to the latest Frasnian to earliest Fammenian faunal stages. This fluvial system also contains overbank mud deposits that underwent pedogenic modification prior to burial and are preserved as paleosols, which indicate the paleoenvironment of formation. This study focuses on outcrop and petrographic investigation of two paleosols at the TRN locality based on their proximity to the fossil-bearing channel lag. These paleosol profiles are both stratigraphically subjacent to the fossil-bearing conglomerate. Paleoenvironmental indicators recorded in these (paleo)vertisols, such as pedogenic slickensides, wedge-shaped peds, and lattisepic clay fabric, indicate an environment that had seasonal wet and dry varialbility. Pedogenic-carbonate nodules and rhizoliths, also identified in these profiles, suggest formation under an ustic moisture regime where evapotranspiration exceeded precipitation. This paleoenvironmental interpretation is not atypical to others reported from the Middle to Late Devonian age paleosols in the Catskill Basin.