The reconstruction of palaeoclimatological changes from mineralogical and geochemical compositions of loess and alluvial loess profiles

Abstract

The study is concerned with the reconstruction of palaeoclimatological changes in (alluvial) loess profiles by means of mineralogical and geochemical criteria. For this, the intensity of chemical weathering (palaeosoil formation) is taken from the ratios of soluble cations to hydrolysates (e.g. Na₂O/Al₂O₃; K₂O/TiO₂) or the degree of corrosion of minerals. Examples of study are (a) a part-profile of alluvial loess in the Wadi Feiran, Sinai, and (b) five loess profiles from the region around Bonn, Germany. Changes in palaeo-humidity are mirrored by geochemical variations, changes in palaeotemperatures by the amount and types of clay minerals.