BIOESTRATIGRAFÍA EN BASE A QUISTES DE DINOFLAGELADOS DE LA FORMACIÓN CHENQUE (MIOCENO), PROVINCIA DEL CHUBUT, ARGENTINA

Susana Palamarczuk, Viviana Barreda

Abstract


An outline of the dinoflagellate cyst distribution in the Chenque Formation (Chenque section), which crops out in the San Jorge Basin, Chubut Province is provided. Twenty one dinocyst species were recognised from 18 samples covering a sequence 200 m thick. The most abundant taxa are: Lingulodinium hemicystum Me Minn, Operculodinium centrocarpum (Deflandre and Cookson) Wall, Spiniferites spp., Hytrichokolpoma rigaudiae Deflandre and Cookson, Cannosphaeropsis utinensis Wetzel and Reticulatosphaera actinocoronata (Benedek) Bujak andMatsuoka. The biostratigraphically key species Tuberculodinium vancampoae (Rossignol) Wall and Hystichosphaeropsis obscura Habib are also present. The previously assigned late Oligocene?- Early Miocene (most probably Early Miocene) age based on continental palynomorphs is confirmed. Quantitative analysis of both marine and continental palynomorphs indicates a regressive trend towards the top of the section.

Full Text:

 Subscribers Only