Análisis Preliminar de Estructuras Geocriogénicas mediante Texturas de Grano de Cuarzo con la Aplicación del Microscopio Electrónico

DARIO TROMBOTTO

Revista de la Asociación Geológica Argentina

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 1985 vol. XL p. 184 - 201

0004-4822

The surface textures of quartz grains are well known for different sedimentary environments. Nevertheless, the textures of cryogenic environments, especially in relation to their active aspects, are not yet so well known. In this paper the parameters and micrographic descriptions of sand-size quartz grains related to the most important periglacial forms of the Cordón del Plata, Mendoza, Argentina, are indicated. These are: 1)soligelifluction structures of short transport on slope debris; 2) rock glaciers; 3) mud circles; 4) cryometeorization regolithe and 5) snow-debris avalanche channels. The analysis of the surface textures show that they are a result of generally combined physical-chemical mechanisms of the Andean cryogenia. Original categories for mechanic or chemical effects according to their prevalence under the microdynamic of periglacial are distinguished. It should be noted that in some forms cryoarid, cryodampness, or other conditions that result from a combination of both according to local circumstances, are predominant.