Cimentation et structures sédimentaires des beach-rocks: genèse et critères d'identification in Le beach-rock.

Auteurs :
DAVAUD, E.
STRASSER, A.
Comité National Français de Géographie, France
Centre National de la Recherche Scientifique. (CNRS). GIS Maison de l'Orient Méditerranéen, France
Université Lyon II, France

Description :
Two examples of carbonate-beachrock formation have been studied in Tunisia and on the Bahamas. It appears evident that cementation takes place under a cover of sediment where the carbonate grains are immobilized and where primary cements are precipitated in a marine or fresh-water, phreatic or vadose environment close to the water table. Oblique beach stratification and keystone vugs (typical for the swash zone) are thus preserved. Coastal erosion exposes this preferentially cemented layer, and marine cementation in the intertidal zone further indurates the rock. Wave action often washes away the underlying non consolidated sediments. This causes the beachrock to break into blocks which may glide into the subtidal zone.


Type de document :
Congrès

Source :
Colloque, 1983, p. 41-50, Références bibliographiques : 22 réf.

Date :
1984

Identifiants :
isbn : 2-903264-37-6

Editeur :
Pays édition : Inconnu