Chemical and mineralogical changes in a polygenetic soil of Galicia, NW Spain

The soils of Galicia, NW Spain, developed on gabbro often include one or mo re buried profiles. In the modern overlying soil, gibbsite is common and th e Fe oxyhydroxides include maghemite. In the buried soil interstratified ka olinite-smectite is abundant, gibbsite is present in traces and the Fe oxyh ydroxides are mostly formed by goethite. Chemical and mineralogical data sh ow that the modern soil has developed under strongly leaching conditions th at contrast with those in which the buried soil formed. We suggest that the interstratified kaolinite-smectite is a relict mineral that helps reconstr uction of the pedogenetic history of these soils. (C) 2001 Elsevier Science B.V. All rights reserved.