Montagnes et vallées d'Andorre: carte géomorphologique (1973-1980)

(ENG) Mountains and valleys of Andorra: This poster presents the geomorphological map (1/50 000) of Andorra, made from the interpretations of aerial photography and field investigations (1980). The Pleistocene glaciation gave important features to the landscape but glacial landforms have left high planation surfaces, some of which have been tilted by late tectonic movements. Glacial accumulation mapping allows a relative chronology. The glacial cycle which most marked the Andorra mountains was characterized by an expansion phase followed by a stationary phase, during which a glaciolacustrin complex built up in La Massana basin, linked to this valley's obturation by the principal glacier. Then a post-maximum phase is mapped. Finally a glacial phase occurred in the late glacial period, represented by block-covered and rock glaciers which left abundant moraines on cirque's floors. After the deglaciation, the landscape was modified by gravitational and fluvial readjustments.