ASSESSMENT OF WEATHERING RATES IN DUTCH LOESS AND RIVER-CLAY SOILS ATPH 3.5, USING LABORATORY EXPERIMENTS

Weathering rates in 12 horizons of soils developed in loess and clay s ediments were measured by means of laboratory experiments. The experim ents were carried out by percolating thin columns containing approxima tely 2 g of soil material. Despite the small amount of sample used, th e results were fairly reproducible. Weathering rates in loess soils we re 0.8 to 8 times higher than rates measured in sandy soils. The rates in river-clay soils were 4 to 90 times the rates in sandy soils. The weathering rates of the base cations (BC), especially Ca and Mg, stron gly increased with clay content. Significant relations were found betw een the mineralogical composition, total element content and texture c haracteristics of the samples and the measured weathering rates. (C) 1 988 Elsevier Science B.V. All rights reserved.