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Modern soils across the Chinese Loess Plateau exhibit strong but disputed correlation between their pedogenic magnetic content and annual rainfall. A soil magnetism/rainfall transfer function could provide a quantitative proxy of Quaternary rainfall for this region. However, some argue that ’magnetic dilution’, through spatially varying fluxes of weakly magnetic dust, controls the soil magnetic properties. Here, we test the soil magnetism/rainfall couple by examining 22 Russian steppe soils (free of present dust accumulation) across a climatic transect. From the semi-arid Caspian region to the more humid Caucasus, the soils display systematic increases in topsoil ferrimagnetic concentrations. With the exception of climate (and its co-variant, vegetation), soil-forming factors are essentially constant across this stable area. Hence, the soil magnetic variations dominantly reflect climate and from statistical analysis, principally rainfall. Further, the Russian steppe magnetic/rainfall relationship matches that observed for the Chinese Loess Plateau. These independent data thus substantiate the soil magnetism/rainfall climofunction and, by inference, eliminate ’dust dilution’ as a significant magnetic factor. (C) 2002 Elsevier Science Ltd. All rights reserved.