¹⁰Be application to soil development on Marion Island, southern Indian Ocean

Marion Island, located in the southern Indian Ocean, constitutes the summit of an active shield volcano. It is a small terrestrial environment where glacially abraded bedrock became exposed c × 10 kyr ago. These conditions provide an interesting possibility for the assessment of ¹⁰Be accumulation rates and their application to soil erosion studies on the island. ¹⁰Be concentrations were measured in precipitation, soil profiles and an Azorella selago cushion plant. The data reveal a ¹⁰Be precipitation flux several times higher than model prediction. Estimation of the ¹⁰Be accumulation based on the soil inventory suggests a span between 2000 and 7000 yr. This time span is not in accordance with the accepted notion that the island was covered with ice about 10,000 yr ago and suggests either removal of ¹⁰Be from the soil profile, an overestimated Holocene ¹⁰Be-flux or a delayed soil development history. Our results provide new data on ¹⁰Be concentrations from the sub-Antarctic islands and contribute towards enlarging the southern-hemisphere ¹⁰Be database.