干旱区生态环境知识资源中心

Soil formation under and conditions is usually weak and it is very difficult to identify palaeo-sols. Our studies suggest, that cadmium depletion indicates initial pedogenesis and, therefore, even short humid phases in desert margin areas. The geochemical composition of loose sediments and soils in the northern Atacama Desert around Palpa/southern Peru (14.5 degrees S) offers appropriate natural field-lab conditions to studying differences in total and mobile cadmium contents. Our preliminary results indicate a causal relationship between loss in total cadmium content - along with an increase in mobile cadmium content - and soil formation, triggered by a temporary vegetation cover. Cadmium dynamics archive pedogenetic impact as a result of former, more humid conditions at the desert margin. This may be used for palaeoenvironmental studies in drylands.