La sédimentologie et les foraminifères bartoniens et priaboniens des coupes d'arguis (Prépyrénées aragonaises, Espagne). Incidence sur la corrélation des biozones à la limite Bartonien/Priabonien

Abstract

The sedimentological study of Arguis anticline in the Jaca basin (south-central Pyrenees, Spain), has shown the overall progradation of a deltaic system, which progressively overlap the structure since Bartonian. The Arguis Marl and Belsué-Atarés Formation which correspond to these sediments contain 206 species of benthic foraminifera. They represent outer and inner shelf depositional environments. Planktonic foraminifera define Morozovella lehneri (with uncertainty), Truncorotaloides rohri s. l., Dentoglobigerina eocaena and Globigerinatheka semiinvoluta zones. Interregional correlations put forward substantial differences between different regions of the Tethys. In central and western Europe as well as in the Arguis sections, N. fabianii and N. garnieri, which mark Priabonian, probably appear coevally with G. semiinvoluta. In Egypt, this event occurs later in the same zone. In the first region, bartonian nummulites ( N. perforatus, N. millecaput, etc.) disappear before that zone, whereas in Armenia they seem to coexist with N. fabianii. These uncertainties show that the definition of the Bartonian/Priabonian boundary should be preceded by the revision of numerous sections, in order to better establish the correlation of biozones of these stages.