The Middle and upper Devonian conodont sequence from la Guardia d'Àres sections (Spanish central Pyrenees)

Abstract

The analysis of conodont faunas from the Comabella Formation at La Guardia d'Àres in the Spanish Central Pyrenees improves the biostratigraphical characterization of this stratum. Forty-seven taxa spanning from the Eifelian through the Lower Frasnian are identified and described. The lower part of the formation starts in the Eifelian kockelianus Zone. The Eifelian/Givetian boundary can be identified by the entry of the index taxon Polygnathus hemiansatus. The Givetian part of the section is tectonically disturbed, affecting mostly the confident recognition of the rhenanus/varcus and the Upper varcus zones. All other Givetian zones are identified either by the defining index taxa or by the characterizing taxa. The Ancyrodella sequence permits recognition of Lower Frasnian MN1-MN3 zones. Direct comparison with Boersma's data shows a strong chronostratigraphical discrepancy and their data are reinterpreted.