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Climatic Geomorphology
Figure 25.46. Basic scheme of slope evolution (Bigarella and Andrade, 1965). Stages depicted are:
(a) extensive intermontane surface formed by pediplanation under arid climate; (b) and (c) slight erosion of
the planated surface caused by a slight lowering of the local base level of erosion due to small climatic
fluctuations toward humid conditions within the arid epoch. (d) Generalized dissection of the planated
surface due to onset of humidity. (e) Valley-widening, alluviation, and colluviation accelerated by short
arid episodes within the humid epoch. (f) Escarpment retreat and formation of a pediment surface under
arid conditions. (g) Slight erosion pediment slopes during slight humid fluctuations within the arid epoch.
(h) Generalized incision under a new humid epoch. (i) Widening and alluviation of valleys caused by
episodic climatic fluctuations trending toward increasing aridity.
Climatic Geomorphology
Figure 25.46. Basic scheme of slope evolution (Bigarella and Andrade, 1965). Stages depicted are:
(a) extensive intermontane surface formed by pediplanation under arid climate; (b) and (c) slight erosion of
the planated surface caused by a slight lowering of the local base level of erosion due to small climatic
fluctuations toward humid conditions within the arid epoch. (d) Generalized dissection of the planated
surface due to onset of humidity. (e) Valley-widening, alluviation, and colluviation accelerated by short
arid episodes within the humid epoch. (f) Escarpment retreat and formation of a pediment surface under
arid conditions. (g) Slight erosion pediment slopes during slight humid fluctuations within the arid epoch.
(h) Generalized incision under a new humid epoch. (i) Widening and alluviation of valleys caused by
episodic climatic fluctuations trending toward increasing aridity.