Evolution and opening of closed depressions developed in a quartz-kaolinitic sedimentary substratum at Taubate basin (Sao Paulo, Brazil), and analogy to the slope evolution

The occurrence of dated peat (17,000-12,500 yr B.P.) in the soil in a closed depression in quartz-kaolinitic rocks of the Taubate basin, Brazil, allowed (1) reconstruction of the evolution of this depression, and (2) estimation of the rate of sinking. The analogy with the soil cover of a slope in the same area has shown that this valley developed by the same mechanisms as those of the depression. Chemical erosion is the main agent for the generation of landforms in this region.