Controls on weathering rates at the Susquehanna Shale Hills Critical Zone Observatory, Pennsylvania, USA

Shale Hills, a V-shaped forested catchment located in central Pennsylvania, is the center for collaborative efforts directed towards understanding the creation, function and evolution of soils in a Critical Zone Observatory (CZO). Shales are one of the most weathering-resistant rock types at the Earth surface, and our study at Shale Hills will provide a baseline to evaluate weathering as an important process in global elemental cycles. Here, we compare chemistry and mineralogy in representative soil profiles to the chemistry of streams, groundwaters and soil waters to investigate shale weathering rates on geologic and contemporary timescales.