Artículos de revistas
New conodont taxa and biozones from the Lower Ordovician of the Cordillera Oriental, NW Argentina
Fecha
2017-05Registro en:
Voldman, Gustavo Gabriel; Albanesi, Guillermo Luis; Ortega, Gladys del Carmen; Giuliano, María Eugenia; Monaldi, Cesar Ruben; New conodont taxa and biozones from the Lower Ordovician of the Cordillera Oriental, NW Argentina; John Wiley & Sons Ltd; Geological Journal (Chichester); 52; 3; 5-2017; 394-414
0072-1050
1099-1034
CONICET Digital
CONICET
Autor
Voldman, Gustavo Gabriel
Albanesi, Guillermo Luis
Ortega, Gladys del Carmen
Giuliano, María Eugenia
Monaldi, Cesar Ruben
Resumen
The upper strata of the Santa Rosita and the Acoite formations (Lower Ordovician) exposed at Chulpíos Creek in the Santa Victoria study area of the Cordillera Oriental, NW Argentina, are analysed by means of conodont biostratigraphy. Four conodont zones are analysed for the referred formations, i.e. the Acodus apex, Acodus triangularis, Gothodus vetus and Gothodus andinus zones, on the basis of a collection with ca. 2800 conodont specimens that includes new conodont taxa. Acodus apex Albanesi and Zeballo, Acodus triangularis (Ding), Acodus zeballus n. sp., Gothodus andinus (Rao et al.), Gothodus vetus n. sp., and Paltodus cf. inaequalis (Pander) are described herein. The conodont genus Zentagnathus is diagnosed including two previously known species: Zentagnathus argentinensis (Rao et al.) and Zentagnathus primitivus (Voldman et al.). The Tetragraptus akzharensis and Baltograptus cf. deflexus graptolite zones were identified as well in the ∼1800‐m‐thick stratigraphic section. The incertae sedis Phosphannulus universalis Müller et al. is discussed for the Cordillera Oriental for the first time. The lower part of the Chulpíos section that involves the contact between the Santa Rosita and the Acoite formations is not able to be dated with precision either as upper Tremadocian or lower Floian because the ranges of the index taxa recorded in that interval of the study section span the stage boundary.