Discordance between cosmogenic nuclide concentrations in amalgamated sands and individual fluvial pebbles in an arid zone catchment

► Cosmogenic 10Be, 26Al, 21Ne in sand and individual pebbles from an arid catchment. ► First order agreement between the 10Be, 26Al, and 21Ne abundances in the pebbles. ► Pebbles have an order-of-magnitude more 10Be than do the amalgamated sands. ► Grain size bias result of differential sediment sourcing and transport times. ► Implications for estimating palaeo-denudation rates from depositional surfaces.