A carregar...
Publicação
Evolução geomorfológica desde a última glaciação no Alto Vale do Rio Garona (Pirinéus Centrais)
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 10.84 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
O objetivo desta dissertação é melhorar o estado atual do conhecimento sobre o comportamento glaciário no alto vale do rio Garona, Pirenéus Centrais, e a sua evolução ambiental pós-glaciária, nomeadamente no vale de Ruda, a partir de uma aproximação multidisciplinar usando técnicas próprias da geomorfologia, sedimentologia, deteção remota e modelação.
O alto vale do rio Garona presenta uma ampla distribuição de depósitos e formas glaciárias e periglaciárias formadas por distintos processos geomorfológicos frios herdados e atuais. A paisagem atual é consequência da intensidade e extensão dos glaciares durante a Última Glaciação e a evolução ambiental posterior. Desde a fase de máxima expansão glaciária durante o último ciclo glaciar pleistocénico o processo de deglaciação foi gradual, com quatro fases identificadas: Fase 1- glaciares de vale e pé de montanha (Último Máxima Glaciar global); Fase 2- extensos glaciares de vale (Oldest Dryas); Fase 3- glaciares nas partes altas dos tributários (Younger Dryas); Fase 4- glaciares de circo (Holocénico).
Hoje, não há glaciares na área de estudo e a dinâmica geomorfológica nas partes mais elevadas da bacia do rio Garona, nomeadamente no vale de Ruda, desenvolve-se de acordo com uma estrutura vertical que inclui três domínios geoecológicos: subnival (1.500-1.900 m), nival (1.900-2.300 m) e periglaciário (2.300-2.800 m).
The objective of this thesis is to present data allowing for a better understanding of our present-day knowledge about the glaciation of the upper Garonne valley, Central Pyrenees, as well as its subsequent post-glacial evolution in the Ruda valley. This has been achieved through the use of a multidisciplinary approach combining data from different disciplines, such as geomorphology, sedimentology, remote sensing and modelling. The high lands of the Garonne River include a wide range of glacial and periglacial deposits and landforms left by past and present cold geomorphological processes. The current landscape is a consequence of the intensity and extent of glaciers during the Last Glaciation and the subsequent environmental evolution. Since the last maximum expansion of glaciers occurred during the last Pleistocene glacial cycle, the deglaciation process was gradual, with four different periods: Stage 1- Development of valley and piedmont glaciers (Last Glacial Maximum); Stage 2- Extensive valley glaciers (Oldest Dryas); Stage 3- Glaciers in the upper parts of the valleys (Younger Dryas); Stage 4- Cirque glaciers (Holocene). Nowadays, there are no glaciers in the study area and geomorphological processes in the high lands of the Garonne basin, namely in the Ruda valley, are staggered in altitude following three geoecological areas: subnival (1500-1900 m), nival (1900-2300 m) and periglacial (2300-2800 m).
The objective of this thesis is to present data allowing for a better understanding of our present-day knowledge about the glaciation of the upper Garonne valley, Central Pyrenees, as well as its subsequent post-glacial evolution in the Ruda valley. This has been achieved through the use of a multidisciplinary approach combining data from different disciplines, such as geomorphology, sedimentology, remote sensing and modelling. The high lands of the Garonne River include a wide range of glacial and periglacial deposits and landforms left by past and present cold geomorphological processes. The current landscape is a consequence of the intensity and extent of glaciers during the Last Glaciation and the subsequent environmental evolution. Since the last maximum expansion of glaciers occurred during the last Pleistocene glacial cycle, the deglaciation process was gradual, with four different periods: Stage 1- Development of valley and piedmont glaciers (Last Glacial Maximum); Stage 2- Extensive valley glaciers (Oldest Dryas); Stage 3- Glaciers in the upper parts of the valleys (Younger Dryas); Stage 4- Cirque glaciers (Holocene). Nowadays, there are no glaciers in the study area and geomorphological processes in the high lands of the Garonne basin, namely in the Ruda valley, are staggered in altitude following three geoecological areas: subnival (1500-1900 m), nival (1900-2300 m) and periglacial (2300-2800 m).
Descrição
Palavras-chave
Dinâmica geomorfológica - Alto Vale do Rio Garona - Pirinéus Centrais Glaciação - Alto Vale do Rio Garona - Pirinéus Centrais Deglaciação - Alto Vale do Rio Garona - Pirinéus Centrais Teses de mestrado - 2016