The lithium isotope response to the variable weathering of soils in Iceland

This study has analysed Li isotopes ratios from well-studied soil and pore water profiles Iceland that have the same parent material but experienced different degrees of chemical weathering. Thus, least to most weathered, we vitrosols (V), gleyic andosols (GA), brown (BA), Histosols (H) Histic Andosols (HA). Although weathered H HA soils highest content in clay-sized material, they fractionated δ7Lipore values. In contrast, GA BA waters are for isotopes. Given isotope by clay mineral formation, this appears counter-intuitive. A single trend all samples δ7Li as a function Li/Na suggests controlled process with fractionation factor, case likely formation poorly-crystalline allophane, which dominates “least weathered” soils. rapidly forming secondary over more slowly-forming crystalline clays. The along path shows key here controlling ratio surface is degree uptake minerals. does not necessarily correspond amount minerals present soil, being newly formed passage through or equilibrium solutions at time sampling.