Eifelian (Middle Devonian) to lower Frasnian (Upper Devonian) conodont biostratigraphy in the villech section (Spanish Central Pyrenees)

Abstract

Conodont biostratigraphic research on the Comabella Formation at Villech (Spanish Central Pyrenees), a 54 m thick pinkish-greyish compact hemipelagic limestone section situated in the Compte "subfacies area", reveals an Eifelian to early Frasnian age for the studied interval. The base of the Formation is of lower Eifelian age (costatus Zone), indicated by the lowest local record of Polygnathus angustipennatus, associated with P. partitus. The kockelianus and eiflius zones are recognized in the lower half of the section. The uppermost Eifelian and lowermost Givetian (ensensis and hemiansatus zones, respectively) have not been found so far but might be located in a covered interval. Other biozones recognized in the section are the timorensis-rhenanus/varcus, ansatus, semialternans, hermanni, disparilis and norrisi zones in the Givetian, all indicated by their respective index species and the MN1 Zone (occurrence of Ad. binodosa and Ad. pristina) in the Frasnian. A black shale and limestone layer in the upper part of the Villech section could represent the local signature of the upper part of the global Taghanic Crisis.