Atmospheric dust contribution to the budget of U-series nuclides in soils from the Mount Cameroon volcano

The atmospheric dust contribution to U-series nuclides in soils is evaluated by analyzing two soil and paleo-soil (< 10 ka) profiles from the Mount Cameroon volcano where Sr–Nd–Pb fingerprints are clearly affected by Saharan dust accretion. The comparison of measured U-series disequilibria between bulk soils and associated parent lavas suggests that dust inputs can contribute up to 25% of the U and Th budget in soils whereas chemical weathering affects a maximum of 7% of the U budget. The uniform U–Th isotopic composition of the Saharan dust end-member inferred from the soils and the paleo-soils suggests a relative stability of the Saharan dust isotopic composition during the last 10 ka.

► The U–Th Saharan dust end-member was uniform and stable during the last ~ 10 ka.
► Up to 25% of U and Th budget in soils derive from Saharan dust accretion.
► U redistribution from chemical weathering affects a maximum of 7% of U budget.