@article {White:February 2008:0026-461X:149, author = "White, A.F.", author = "Schulz, M.S.", author = "Stonestrom, D.A.", author = "Vivit, D.V.", author = "Fitzpatrick, J.", author = "Bullen, T.", title = "Solute profiles in soils, weathering gradients and exchange equilibrium/disequilibrium", journal = "Mineralogical Magazine", volume = "72", year = "February 2008", abstract = "The spatial and temporal changes in hydrology and pore water elemental and 87/86Sr compositions were used to determine contemporary weathering rates in a 65 to 226 ky old soil chronosequence formed from granitic sediments deposited on marine terraces along coastal California. Cl-corrected Na, K and Si increased with depth denoting inputs from the weathering of plagioclase and K-feldspar. Solute 87/86Sr exhibited progressive mixing of sea water-dominated precipitation with inputs from less radiogenic plagioclase. Linear approximations to these weathering gradients were used to determine plagioclase weathering rates of between 0.38 and 8.9 × 10−15 moles m−2 s−1. The lack of corresponding weathering gradients for Ca and Sr indicated short-term equilibrium with the clay ion exchange pool which requires periodic resetting by natural perturbations to maintain continuity, in spite of soil composition changes reflecting the effects of long-term weathering.", pages = "149-153(5)", url = "http://www.ingentaconnect.com/content/minsoc/mag/2008/00000072/00000001/art00033" doi = "doi:10.1180/minmag.2008.072.1.149" }