Inadequate pedogeomorphic evidence for dry and cold climatic conditions in southeastern Brazil

The recent paper by Lichte & Behling (1999) in this journal entitled "Dry and cold climatic conditions in the formation of the present landscape in southeastern Brazil" is subtitled "An interdisciplinary approach to a controversially discussed topic". We consider their conclusions to be as controversial as the topic they address. The controversial topic is the mode of formation of stone-lines and the overlying mantle of fine earth, said by the authors to be of aeolian origin, which are widespread in the hilly portions of the dissected Sulamericana plain landscape of southeastern Brazil. We take issue with the stated explanations of both features and consider that they do not necessarily provide paleoclimatic evidence. We suggest that the authors have not presented sufficient evidence to exclude viable alternative explanations that include both present and past processes - explanations that have been applied elsewhere to somewhat similar situations. The focus of the paper is the origin of a soil mantle atop a stone-line, which is addressed by their interdisciplinary approach that involves palynology, dating, particle size analysis, mineralogy and discussion about the formation of the stone-line. We consider the issue of the stone-line first.