GEOMORPHOLOGY OF QUARTZITIC SLOPES IN COLD REGIONS. THE EXAMPLE OF NORTH-WESTERN EUROPEAN MOUNTAINS. GÉOMORPHOLOGIE DES VERSANTS QUARTZITIQUES EN MILIEUX FROIDS L'EXEMPLE DES MONTAGNES DE L'EUROPE DU NORD-OUEST

• Main Author: Sellier, Dominique
• Other Authors: Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN), Université de Paris I - Panthéon Sorbonne, Alain Godard
• Format: Thesis
• Language: French
• Published: HAL CCSD 2002
• Subjects: Quartzite; Geomorphology of basement regions; Slopes; Cold regions; Mountains; European Atlantic seaboard; Norway; Scotland; Ireland; Géomorphologie des socles; Versants; Milieux froids; Montagnes; Façade atlantique européenne; Norvège; Ecosse; Irlande; geo; envir; Arctic; Dovrefjell
• Online Access: https://hal.archives-ouvertes.fr/tel-02164805/file/th%C3%A8se%20d%27Etat%20D.%20Sellier%202002.pdf; https://hal.archives-ouvertes.fr/tel-02164805

Summary : GEOMORPHOLOGY OF QUARTZITIC SLOPES IN COLD REGIONS. THE EXAMPLE OF NORTH-WESTERN EUROPEAN MOUNTAINS. The aim of this study is to characterise quartzite landforms on different scales in cold environments, focusing mainly on slopes, and using mountains in Northern Ireland, Scotland and Norway as field of study. Theses fields range in latitude from the 55th to the 62nd parallel, in altitude from 500 m to 2 300 m, and are situated near the Atlantic seaboard. They consist of thick quartzite series and provide a sampling ranging from mountains with glacionival level (Dovrefjell), through high mountains with an active periglacial level spread over 1 000 m (Rondane, Telemark) and finally to oceanic mountains with an arctic-alpine zone. The approach is based on a double comparison : firstly, between rocks : specifying the position of quartzite in scales of resistance according to different periods, thus considering the structural parameters secondly, between mountain environments, defining the place of quartzitic landforms according to environments, present or past, and determining the rate of evolution, therefore considering morphogenetic and paleogeographical variables, such as zonation and glacierization. A typical quartzitic landscape can be found in cold regions as can one of sandstone, granite, gneiss or schist. Quartzite can be distinguished by dominant mountains which date from Pre-Quaternary times, during which they were the more resistant of rocks. They can be recognised also by the considerable frequency of scree and blockfields this is the result of their susceptibility to the glacial and periglacial processes, which are consequence of their extreme properties : siliceous composition, recrystallization, hardness, brittleness, splitting, low porosity, high resistance to chemical weathering. This thesis attempts a morphological and dynamical typology of quartzite slopes : structural forms, glacial slopes, scree slopes, Richter slopes, mature slopes with successions of glacial and periglacial ...