Paleopedology of Terrae rossae—Rodoxeralfs from quaternary calcarenites in NW Morocco

Selected Terrace rossae or Rhodoxeralfs from calcarenites, in all probability of Mid-Pleistocene age, in the vicinity of Rabut show a strong mineral weathering and a considerable to extensive formation of clay minerals especially of kaolinites. Main sources of pedogenic kaolinites, mostly of a disordered structure and poor cristallinity, are primary feldpars (> 2 μm) and smectites (2-0.2 and <0.2 μm) inherited in the calcerenites as the parent material. The Rhodoxeralfs contain more or less allochtonous eolian material: these additional eolian inputs are in parts probably connected with the lowering of the sea level in the cool (glacial) stages, which results in an extended beach area of 10–15 km to the west in this region. However, the periods of the formation of the investigated relict (polygenetic) paleosols extended over most parts of the Brunhes epoch, including those of the cool (glacial) stages. The todayʹs patchy distribution of the Terrae rossae is a result of a land degradation especially the removal of earlier dense forest cover followed by severe soil erosion due to human activity which is still grossly underestimated in comparison to climate variations in this area.