Resumen

PEREZ PANERA, Juan Pablo  y  ANGELOZZI, Gladys Noemí. Late Cretaceous - Tertiary Calcareous Nannofossils From The Bb Iii A X-1 (Bahía Blanca) Borehole, Colorado Basin, Argentina. Ameghiniana [online]. 2006, vol.43, n.3, pp.557-565. ISSN 1851-8044.

A quantitative biostratigraphic study based on calcareous nannofossils, using cutting samples from the BB III A x-1 (Bahía Blanca) borehole placed in the western area of the Colorado Basin, off shore, is presented. According to the marker species, the stratigraphic column was divided in nine sections included in the Miocene, Oligocene, middle-late Eocene, early Paleocene, and late Campanian-Maastrichtian. The study has shown a rich nannoflora with species cited for the first time in the Colorado Basin. Early Danian, late Campanian and Maastrichtian biozones and a well defined Cretaceous-Tertiary boundary were recognized.

Palabras clave : Calcareous nannofossils; Late Cretaceous; Tertiary; Biostratigraphy; Colorado Basin; Argentina.