10Be accumulation in a soil chronosequence

We have measured the concentration of the cosmogenic isotope¹⁰Be in soil samples from various horizons at six sites, including three independently dated Rappahannock River terraces and a previously undated Piedmont soil to which we have assigned an age. All of the incident¹⁰Be can be accounted for in one of these soils and a second is within a factor of two. In three soils, whose concentrations vary widely with depth, a significant fraction of the incident¹⁰Be cannot be accounted for. Incomplete sampling, and enhanced Be mobility caused by organic components, are the probable reasons for the low inventory of Be from these three soils. Overall, the data from these six sites indicate that¹⁰Be accumulation could be used to assign ages to soils if Be is not mobilized and lost from the soil profile.