recent sediments, resulting during the Quaternary. The first group includes principally schists and quartz-feldspar, greywackes and quartzites with meta-crystals, such as andalusite, cordierite and sillimanite. These sedminentary deposits are prominently preserved in two linear patches: Vale das Antas and Louriça, near Castro Laboreiro, between two granite structures. The most recent geological formations are those created by fluvial, torrential and glacial deposits. During the Pleistocene (approximately 1.8 to 0.001 Ma ago) climatic variations resulted in an extension of glacial fields to the mid-latitudes. While there are no remnants of glaciers now, their Ice Age products (U-shaped valleys, moraines, glacial deposits, polished and natural granite surfaces) are identified in the Serra da Peneda, Serra do Soajo and Serra do Gerês mountain ranges. The principal watersheds that cross the park are those of the Minho (occupying 2% of the park), Lima (47.8%) and Cávado (50.2%), with brooks and waterfalls common on many of the mountain slopes, in addition to several secondary tributaries (such as the Homem, Rabagão, Castro Laboreiro, and Arado rivers). The Lima cuts across the PNPG east to west, while the Cávado serves the southern limits of the districts of Vila Real and Braga. Fractures in the landscape have confined the rivers to deep, straight valleys and are visible in the younger granite outcrops visible in the uncovered higher altitudes. Owing to the number tributaries, the construction of hydroelectrical dams has been undertaken to generate electricity across six locations: Alto Rabagão, Paradela, Caniçada, Vilarinho da Furna, Touvedo and Lindoso. Soils within the elevated terrains and inclined spaces are non-existent, while the valleys are rich and deep, deposited and transported by pluvial action. These strata are textured, permeable, easily worked, albeit with a weak consistency, and marked by the peculiarities of local agriculture. The incorporation of biomass and elevated precipitation, along with the low autumn-winter temperatures give an origin to the alterations in pH levels. The elevated levels of incompletely decomposed organic material, low in phosphorus and intermittently low/high in potassium, are subject of alluvial deposition. Climate The region of the Parque Nacional Peneda Gerês falls within a transitional zone between the Atlantic and Mediterranean environments, and is influenced by various climatic systems: Atlantic, Mediterranean and Continental. Its climate is greatly influenced by the topography; the mountains exert a barrier effect to the passage of hot and wet air masses coming from the Atlantic Ocean, resulting in elevated precipitation throughout the year.