Cartographic arguments for a tectonic effect on regional soil distributionin the Armorican Massif

The study of pedological maps from the Armorican Massif evidenced the effec t of recent tectonics (500 000-700 000 years BP) on the regional hydromorph ic soil distribution. Blocs in relative uplift were characterized by a low proportion of hydromorphic soils, whereas a higher proportion marked blocs in relative downlift. Such clear differences can be related to the denudati on regime, which affects topography and saprolite properties, two soil form ation factors. Improvements in soil modelling may be achieved by taking int o account the regional trends of soil waterlogging and hydromorphy. ((C) 19 93 Academie des sciences / Editions scientifiques et medicales Elsevier SAS .).