Impressions of past climates on 1 soils and soil materials are not easily obliterated by time. Morphological and chemical features of the weathering record may be of considerable aid in reconstructing the past environments as well as in understanding the present ones. It should be possible not merely to recognize the qualitative aspects of the past climates, by the morphological-geochemical analysis, but also to attempt establishment of semi-quantitative time scales, of indices of the duration of this or that component of the climatic sequence. This analytical approach to the study of ancient soils, palaeopedology, is now at its beginning. The large but disorganized body of observations and data in this field is still lacking in perspectives and interpretations. The tentative conclusions developed herein are subject to revision and change, and it is our hope to verify and to enlarge this study in the near future, time and opportunity permitting.