Graptolites ordovicicos en la sierra de Cajas, cordillera oriental de Jujuy, Argentina

Abstract

ABSTRACT. Ordovician graptolites from sierra de Cajas, eastern Andes, Jujuy, Argentina. A graptolite assemblage of early Ordovician age has been found in the northern region of Sierra de Cajas (northwestern Argentina). The fossil bearing beds consist of sandstones and shales of the Parcha Formation (=Acoite Formation). The fauna contains the following genera and species: Didymograptus sp., Isograptus caduceus cf. l. caduceus caduceus (Salter), Kinnegraptus sp., Tetragraptus quadribrachiatus (Hall), cf. T. bigsbyi (Hall), T. phyllograptoides cf. phyllograptoides Strandmark and cf. Skiagraptus sp. The graptolite fauna is assigned to the late Arenigian-early Llanvirnian.