Trends in grain size and BET surface area in cold-arid versus warm-semiarid fluvial systems

Abstract Sediment grain size and surface area impose critical controls on the rates of chemical weathering, even in cold-based (i.e., polar) glacial systems, where extensive chemical weathering traditionally has been considered minimal owing to low temperatures. Production of fine-grained material increases the surface area of sediments, priming mineral surfaces for chemical weathering. Comparison among grain size and reactive surface area of sediments along granitoid-sourced fluvial transects between a cold–arid, glacial (Wright Valley, Antarctica) and a warm–semiarid, nonglacial (Wichita Mountains, Oklahoma) environment indicates opposing trends downstream within the silt and clay (