LA CUENCA DE ANTEPAÍS EOCENA-OLIGOCENA EN EL NOA: PRIMEROS INDICIOS DE DEFORMACIÓN INTRA-CUENCA

CECILIA DEL PAPA; ALEJANDRO ARAMAYO; PATRICIO PAYROLA; FERNANDO HONGN; CAROLINA MONTERO; MARGARITA DO CAMPO; VIRGINIA DERACO; CLAUDIA HERRERA; IVÁN PETRINOVIC; LAPIANA, AYELEN

Relatorio XX congreso geológico Argentino

XX congreso geológico Argentino

Lugar: San Miguel de Tucumán; Año: 2017; p. 237 - 253

The Eocene-Oligocene foreland basins in NW Argentina: evidence of early intra-basinal deformation. The knowledge concerning the evolution of the Paleogene foreland basins in the Central Andes has been largely improved, especially the model that considers the development of the Paleogene basins as a broken foreland since their earlier stages.In this contribution, we present a synthesis of the recent data and ideas coming from different research groups on Paleogene units of NW Argentina that allow us to compose a new map of sedimentation-deformation in the Puna and Eastern Cordillera regions. The Geste Formation and equivalent units (Quiñoas Formation) recognized in the Puna area display evidence of paleo-drainage re-organization and local provenance of the detritus coming to the basin from the west and east directions. In the same way, Quebrada de los Colorados and Casa Grande formations identified in the western Eastern Cordillera, depict unconformity relations with the underlying Salta Group, and also show many evidences of intra-basinal deformation such as growth-strata and centimeter to meter scale deformation structures. Finally, the Tin Tin Member of the Angastaco Formation presents angular unconformity relations with the Quebrada de los Colorados Formation and intra-formational growth-strata structures. In summary, the unconformity relations of the different Eocene-Oligocene units with the underlying strata, the identification of intra-formational unconformity surfaces, the local characteristics of the provenance recognized, along with the presence of growth-strata in many of the units described, contribute to support a model of complex evolution of the Paleogene foreland basins under a propagation pattern of deformation for the Central Andes in NW Argentina.