Ordovician acritarchs from northwestern argentina: new insight into the biostratigraphy and paleonvironmental aspects of the Central Andean Basin and Famatina

RUBINSTEIN, CLAUDIA V.

SERIE CORRELACIÓN GEOLÓGICA

Instituto Superior de Correlación Geológica

Lugar: Tucumán; Año: 2003 vol. 17 p. 125 - 130

1514-4186

Ordovician sedimentary rocks are widely distributed in Argentina. The largest exposures correspond to the Central Andean Basin (Figure 1), comprising the Puna, Cordillera Oriental (Eastern Cordillera), and Sierras Subandinas (Subandean Ranges), where strata range in age from the Tremadoc to the Ashgill. Traditionally, the Puna, Cordillera Oriental and Sierras Subandinas have been considered as separate basins, especially because of their Cenozoic geological history, which has imprinted the present morphology. This interpretation was supported by paleontological, lithological and stratigraphical differences, although not always relevant enough to justify the separation of these basins during Ordovician time. New investigations help explain these differences in the context of an integrated foreland basin model for the Ordovician of the Central Andean Region, where a continuous link of variable depositional settings (including inshore?offshore gradients) is represented . In the light of this recent interpretation, an integrated reassessment of acritarch biostratigraphy and paleonvironmental aspects is presented in which acritarch results are compared to those of the Famatina basin