Paper No. 18
Presentation Time: 9:00 AM-6:30 PM
DIAMOND IN THE ROUGH: A NEW OUTCROP OF LATE DEVONIAN HAMPSHIRE FORMATION FLUVIAL AND PALEOSOL REDBEDS IN WEST VIRGINIA
The Late Devonian Hampshire Formation and equivalent Catskill Formation of the northern and central Appalachians are thick packages of red sandstones and shales. The rapid weathering and erosion of these rocks has challenged many studies. However, recent highway construction in the eastern panhandle of West Virginia has uncovered a large Hampshire Formation outcrop, allowing for an exceptional chance to study it in its pre-weathering state. Here we present sedimentological and paleontological details from this outcrop that provide refined understanding of depositional environments and paleoclimates of the Late Devonian of West Virginia. The Diamond in the Rough Road outcrop contains cycles of yellow and maroon sandstones and red shales. At least three, ~10 meter-scale cycles of yellow sandstone-maroon sandstone-red shale are represented. In the yellow sandstones, we have observed erosional bases, cross-bedding, ripple marks, scour features, and plant fossils, an assemblage we interpret as fluvial. Maroon sandstones contain cross-bedding, ripple marks, and localized insect burrows (small termite mounds?), and may reflect eolian deposition. In the red shales, paleosol features such as blocky peds, slickensides, and rhizoliths are abundant. The red shales also contain pale blue-green reduction spots and patches. Vertical, cylindrical, non-branching burrows extending 20+ cm downward from individual bedding planes in the red shale are interpreted as estivation burrows, possibly made from small lungfish. Paleoclimate indicators suggest that wet and dry climate trends may have occurred. Within the one-year period in which we have studied this outcrop, considerable weathering has occurred, illustrating the challenges of sedimentological and paleontological study of red beds.