Supraglacial debris supply in the Cuerpo de Hombre paleoglacier (Spanish Central System) : reconstruction and interpretation of a rock avalanche event

Auteur(s) et Affiliation(s)

CARRASCO, R.M.

Dept. of Geological and Mining Engineering, Univ. of Castilla-La Mancha, Toledo, Espagne

PEDRAZA, J.

Dept. of Geodynamics, Complutense Univ., Madrid, Espagne

DOMÍNGUEZ-VILLAR, D.

National Research Centre on Human Evolution (CENIEH), Burgos, Espagne

WILLENBRING, J.K.

Dept. of Earth and Environmental Sciences, Univ. of Pennsylvania, Philadephia, Etats-Unis

VILLA, J.

Dept. of Geological and Mining Engineering, Univ. of Castilla-La Mancha, Toledo, Espagne

Description :
During the deglaciation stages of the last glacial period a rock avalanche took place on the glacier that occupied the upper sector of the Cuerpo de Hombre Valley (Sierra de Béjar). The material displaced during the avalanche fell onto the ice, was transported by the glacier and later deposited as supraglacial ablation till. The cause of the avalanche was the decompression of the valley slopes after they were freed from the glacier ice (stress relaxation). Reconstruction of the ice masses has been carried out to quantify the stress relaxation that produced the collapse. The rock avalanche took place on a lithologically homogeneous slope with a dense fracture network. The deposit is an accumulation of large, angular, heterometric boulders with a coarse pebble-size matrix. The avalanche can be explained as a relaxation process. In the Spanish Central System paleoglaciers the largest accumulation of morainic deposits occurred after the glacial maximum and the earliest stages of the ice retreat.

Type de document :
Article de périodique

Source :
Geografiska annaler. Series A. Physical geography, issn : 0435-3676, 2013, vol. 95, n°. 3, p. 211-226, nombre de pages : 16, Références bibliographiques : 2 p.

Date :
2013

Editeur :
Pays édition : Suede, Stockholm, Svenska sällskapet för antropologi och geografi

Langue :
Anglais