Present-day hydro-aeolian processes in the Serra do Gerês, NW Portugal
Abstract
Micro-scale fcatures developed in coarse sand deposits present in the higher interfluves of the Serra do Gerês are studied. Two main types of features were identified: simple lag-surfaces and microaccumulations against obstacles. A morphological typology for the later is presented. The morphological study, grain-size analysis and comparison of the aspeet and location of the micro-accumulations against obstacles with shrub anemomorphisms allowed a first genetical interpretation for the studied features. This approach emphasises the importance of water and wind erosion in the Serra do Gerês higher areas. The role of water erosion in the genesis of simple lag-surfaces and micro-accumulations against obstac1es is mainly by washing of the fines. Wind erosion acts twofolds through accumulation and deflation of fines.