Carbonífero superior en la Cordillera Frontal (Provincia de San Juan, Argentina): características e implicaciones regionales

• Autores: Pere Busquets Buezo, Ferrán Colombo Piñol, Núria Solé de Porta, Nemesio Heredia Carballo, Luis Roberto Rodríguez Fernández, Joaquina Álvarez Marrón
• Localización: Geogaceta, ISSN 0213-683X, Nº. 32, 2002, págs. 251-254
• Idioma: español
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• Resumen

  • Previous dating of the limestones at the upper part of the Agua Negra in the Quebrada de las Ánimas provided an unconclussive age of Silurian-Devonian. A palynological analysis has been carried out with the aim of improving the existing dating, particular attention has been paid to collecting samples from the partially metamorphic limestones at the top of the succession. The palynomorphs found accumulated during the Upper Carboniferous and they are in association with other palynomorphs and younger chitinozoa (Devonian) reworked from previously accumulated sediment. During the Condwana Cycle this region of the Frontal Cordillera passed from being a retroarc basin (Ramos 7 988), in which the sediments come from eroding relieves of the Precordillera and the Sierras Pampeanas, to a position in which the growing relieves of the volcanic arc that provided sediments also caused the partial cannibalisation of previously accumulated sediments. Previous interpretations of the Frontal Cordillera (Chilenia Terrane) being placed in a paleolatitude away from Condwana were based in the presence of Silurian-Devonian hot water stromatolithic limestones. Our results suggest that previous geodynamic interpretations should be reviewed