Zur Bodenstratigraphie im Nördlichen Afrika

Based on a pedostratigraphical comparison the author tries to draw palaeoecological conclusions for the Cainozoic of Africa north of the equator. For this purpose pedological literature of each of the present climatic zones was stratigraphically evaluated, own investigations concerning the central Sahara were added. Deep-sea sediments off NW Africa and late Quaternary oscillations of Lake Tchad were included as well. Figure 1 shows the chronological comparison. Particularly with various intensities of soil formation, visible in different taxonomic soil units, it can be demonstrated that, already during the Tertiary, there were different bioclimatic conditions in the lower latitudes of Africa. A significant alternation of drier and humid climates must be considered in the central Sahara since the Oligocene. The relief sequence in the permanent humid tropics is in principle similar to the sequence in the humid extratropics. Formations of glacis and soils in dry areas (tropics and subtropics), however, can still not be correlated with each other. As in pure degradation areas important indicator soils are closely correlated with morphological elements of plains. Here we have to take pedostratigraphical gaps into account. It is possible that morphological plains were destroyed during the complete development of the relief when there were times with different intensities of planation processes.