Linke et al. (2024): The geochemical evolution of basalt Enhanced Rock Weathering systems quantified from a natural analogue
T. Linke, E.H. Oelkers, K. Dideriksen, S.C. Möckel, S. Nilabh, F. Grandia, S.R. Gislason IN: Geochimica et Cosmochimica Acta, 370, https://doi.org/10.1016/j.gca.2024.02.005
Substantial quantities of fine-grained basaltic dust have fallen on South Iceland soils over at least the past 3300 years, making this region an ideal natural analogue to define the long-term consequences of current Enhanced Rock Weathering efforts. A relatively pristine South Iceland Gleyic/Histic Andosol, 3 m in height, receiving approximately 1250 mm of rainfall annually was selected for this study. This soil receives an estimated 500–800 g/m2 y of basaltic dust. The soil waters in this system were regularly sampled as a function of depth from May to November 2018. The fluid pH, alkalinity and the concentrations of most major elements increased with depth as the fluids became more reduced. In contrast, whereas numerous toxic trace metals are initially released to the fluid by the dissolution of the basalt near the surface they are scavenged at depth likely due to their uptake by secondary minerals.