The stratified slope deposits of Tierra del Fuego (Argentina) as an analogue for similar pleistocene deposits in Galicia (NW Spain)

Augusto Pérez-Alberti, Pedro P. Cunha

Resumen


This paper focuses on slope dynamics in schist/slate materials in cold humid environments. It characterises the sedimentological features and controls involved in the for-mation of stratified slope deposits in two areas with similar topographical, lithological and climatic characteristics. In both areas, the slopes have dips >30º and the dominant rock types are schists and slates. In the case of Tierra del Fuego, the sedimentary deposits studied are modern; those in Galicia are Pleistocene in age. The slope processes operating in Tierra del Fuego, gen-erating modern stratified slope sedimentary deposits, throw light upon the interpretation of similar ancient sediments studied in Galicia. This comparative study reveals the fundamental role played by snow and freeze-thaw cycles in the creation of stratified slope deposits. Firstly, snow cover has a direct effect on the slope, compacting sediments, keeping ground temperature stable during winter, or moving clasts as they slip down the slope or act as a slide ramp. Indirectly, as the snow melts, it creates surface run-off and mud or gravel slides. Secondly, the activity generated by numerous freeze-thaw cycles results in the vertical mobility of clasts. However, the continuous loading of sediments on the slope hinders the formation of coarse-grained pavement. Thirdly, the rock type and slope steepness play an important role in the creation of stratified slope deposits.

Palabras clave


Stratified slope deposits; Cryonival processes; Fuegian Andes; Argentina; Serra do Courel; Galicia; Spain

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DOI: http://dx.doi.org/10.18002/pol.v0i28.4293

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Copyright (c) 2016 Augusto Pérez-Alberti, Pedro P. Cunha

Licencia de Creative Commons
Este obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial-CompartirIgual 4.0 Internacional.

Polígonos
Revista de Geografía

Contacto: jose.cortizo@unileon.es
Soporte técnico: journals@unileon.es

DOI: http://dx.doi.org/10.18002/pol

I.S.S.N. 1132-1202 (Ed. impresa)(n. 1 a 24)
e-I.S.S.N. 2444-0272

Editada por el Área de Publicaciones de la Universidad de León