Meteoric ¹⁰Be in soil profiles - A global meta-analysis

In order to assess current understanding of meteoric ¹⁰Be dynamics and distribution in terrestrial soils, we assembled a database of all published meteoric ¹⁰Be soil depth profiles, including 104 profiles from 27 studies in globally diverse locations, collectively containing 679 individual measurements. This allows for the systematic comparison of meteoric ¹⁰Be concentration to other soil characteristics and the comparison of profile depth distributions between geologic settings. Percent clay, ⁹Be, and dithionite-citrate extracted Al positively correlate to meteoric ¹⁰Be in more than half of the soils where they were measured, but the lack of significant correlation in other soils suggests that no one soil factor controls meteoric ¹⁰Be distribution with depth. Dithionite-citrate extracted Fe and cation exchange capacity are only weakly correlated to meteoric ¹⁰Be. Percent organic carbon and pH are not significantly related to meteoric ¹⁰Be concentration when all data are complied.The compilation shows that meteoric ¹⁰Be concentration is seldom uniform with depth in a soil profile. In young or rapidly eroding soils, maximum meteoric ¹⁰Be concentrations are typically found in the uppermost 20 cm. In older, more slowly eroding soils, the highest meteoric ¹⁰Be concentrations are found at depth, usually between 50 and 200 cm. We find that the highest measured meteoric ¹⁰Be concentration in a soil profile is an important metric, as both the value and the depth of the maximum meteoric 10Be concentration correlate with the total measured meteoric ¹⁰Be inventory of the soil profile.In order to refine the use of meteoric ¹⁰Be as an estimator of soil erosion rate, we compare near-surface meteoric ¹⁰Be concentrations to total meteoric 10Be soil inventories. These trends are used to calibrate models of meteoric ¹⁰Be loss by soil erosion. Erosion rates calculated using this method vary based on the assumed depth and timing of erosional events and on the reference data selected.