Date of Presentation
4-28-2026 9:30 AM
College
College of Science & Mathematics
Faculty Sponsor(s)
Drs. Pfeifer and Trop
Poster Abstract
To test the hypothesis of alpine glaciation in the late Devonian (Famennian) at subtropic latitudes, we present new major element geochemistry and petrographic thin section images from upper Devonian paleosols collected from north-central Pennsylvania (Appalachian Basin). Paleosols, ancient soils, record climate conditions at the time of formation. Major element geochemistry is used to calculate the intensity of weathering which is used for paleoclimate interpretations, and microfabrics observed in paleosol thin section petrography yield important clues about the soil type and degree of pedogenesis in the system. Twenty-three samples were collected from the Catskill and Lockhaven Formation paleosols for geochemical analysis, and seven of these were imaged in thin section. These strata include terrestrial to transitional/shallow marine facies of the Acadian Wedge. Previous work on Catskill Formation paleosols document an apparent increase in arid climate conditions, despite overall paleoclimatic interpretations from the Famennian which document an upsection transition from arid to increasingly humid climate conditions during this time. Preliminary results of paleoweathering indices as calculated from new major element geochemistry inform that there was intermediate chemical weathering in the system during the Famennian. Further work is needed to assess whether the geochemistry of Upper Devonian paleosols in the Appalachian Basin are consistent with upsection increase or decrease in humidity, or if they are consistent with glaciogenic conditions in the paleohighlands (Appalachian Mountains).
Disciplines
Geology
Document Type
Poster
Included in
Geochemistry and Petrography of Upper Devonian (Famennian) Paleosols in the Appalachian Basin of Central Pennsylvania, USA
To test the hypothesis of alpine glaciation in the late Devonian (Famennian) at subtropic latitudes, we present new major element geochemistry and petrographic thin section images from upper Devonian paleosols collected from north-central Pennsylvania (Appalachian Basin). Paleosols, ancient soils, record climate conditions at the time of formation. Major element geochemistry is used to calculate the intensity of weathering which is used for paleoclimate interpretations, and microfabrics observed in paleosol thin section petrography yield important clues about the soil type and degree of pedogenesis in the system. Twenty-three samples were collected from the Catskill and Lockhaven Formation paleosols for geochemical analysis, and seven of these were imaged in thin section. These strata include terrestrial to transitional/shallow marine facies of the Acadian Wedge. Previous work on Catskill Formation paleosols document an apparent increase in arid climate conditions, despite overall paleoclimatic interpretations from the Famennian which document an upsection transition from arid to increasingly humid climate conditions during this time. Preliminary results of paleoweathering indices as calculated from new major element geochemistry inform that there was intermediate chemical weathering in the system during the Famennian. Further work is needed to assess whether the geochemistry of Upper Devonian paleosols in the Appalachian Basin are consistent with upsection increase or decrease in humidity, or if they are consistent with glaciogenic conditions in the paleohighlands (Appalachian Mountains).