IDENTIFICATION AND CLASSIFICATION OF A PRESERVED PALEOSOL FROM THE HUNTLEY MOUNTAIN FORMATION IN PENNSYLVANIA

The Huntley Mountain. Formation is a predominately nonmarine clastic deposit located in northeastern Pennsylvania and contains sediments from the Upper Devonian/Lower Mississippian boundary. The goal of our study is to identify, analyze and classify a thick paleosol deposit on top of this unit. This paleosol is preserved at an outcropping of the Huntly Mtn. Fm. found at the Red Rock Quarry located on the southeastern border of Ricketts Glen State Park. This quarry offers excellent 3D exposures of the Huntley Mtn. Fm. for this study. At this site, recent glacial (Wisconsinan) till overlies this paleosol, although elsewhere it contacts the Lower Mississippian Burgoon Sandstone (Pocono Fm.). The goal of this study is to identify a paleosol from the upper Huntley Mtn. Fm. and interpret how landscape conditions influenced the pedogenesis.

This paleosol deposit, approximately 39 cm thick, is Dusky Red (10R 3/4) with blocky ped structure with underlying relict bedding. Irregular and diffuse greenish gray mottles are present and likely represent drab halos outlining root traces forming from decayed organic matter. The features evidenced in this paleosol suggest a soil that has undergone pedogenesis during periods of wetting and drying from a fluctuating water table. Thin sections were made from vertical and horizontal oriented samples to study the micromorphology of the paleosol horizons. This is aided by X-ray diffraction to constrain the clay mineralogy of this paleosol. This paleosol deposit at the top of the Huntley Mt. Fm. offers insight as to surficial conditions of this site and the landscape at or across the Devonian-Mississippian boundary.