Geochemical behaviors of different element groups during shale weathering at the Susquehanna/Shale Hills Critical Zone Observatory

Major and trace element concentrations were measured in bedrock, regolith and stream sediments from a first-order catchment developed entirely on grey shale in central Pennsylvania, USA. These elements can be classified into five major groups based on statistical data analysis. The presence of different elemental groups is due to the mineralogical origin, cycling processes, and geochemical properties of these elements during soil formation. A better understanding of the behaviors of these elements during chemical weathering would allow for their possible use as natural tracers in Critical Zone processes.

► Statistical analysis on element concentrations of bedrock, regolith, and sediments. ► Element groups with different geochemical behaviors during soil formation. ► Mineralogical, cycling, and geochemical controls during chemical weathering.