Glacial morphology and evolution in the Arritzaga valley (Aralar range, Gipuzkoa)

Abstract

Interpretation of glacial processes during the late Quaternary in the Basque Mountains has been a polemic issue over the last decades. Discussions have been mainly (but not exclusively) focused on the Aralar range (1421m) providing contrasted interpretations. This work presents the results of the analysis of the landforms and deposits of the valley confirming the existence of glacial processes in the Arritzaga valley during the last glaciation generating a glacial body with a front at 800 m, a longitude of 5 Km and 70-100 m of thickness. Glacial processes at such moderate altitudes were linked to particular conditions: snow overfeeding and leeward effect in a cold and very humid climatic context, and an appropriate relief for snow retention.