SciELO - Scientific Electronic Library Online

 
vol.71 número4Sistema geotermal de despoblados determinado a partir de datos magnetotelúricos, valle del Cura, San JuanPrimeros registros del “evento lomagundijatuli” en mármoles paleoproterozoicos del basamento de las Sierras septentrionales de la Provincia de Buenos Aires, Cratón del Río de la Plata índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Revista

Articulo

Indicadores

  • No hay articulos citadosCitado por SciELO

Links relacionados

  • No hay articulos similaresSimilares en SciELO

Compartir


Revista de la Asociación Geológica Argentina

versión On-line ISSN 1851-8249

Resumen

ESCOSTEGUY, Leonardo; GEUNA, Silvana; ETCHEVERRIA, Mariela  y  FRANCHI, Mario. Formación El Bello (nom. nov.), jurásico temprano de la cordillera Patagónica Austral, provincia de Santa Cruz. Rev. Asoc. Geol. Argent. [online]. 2014, vol.71, n.4, pp.575-584. ISSN 1851-8249.

A complete, clastic, continental, 300 meters-thick succession outcrops close to the border crossing of the Mayer River, in the Cordillera Patagónica Austral, unconformably lying on the pre-Jurassic basement (Río Lácteo Formation); it is succeeded transitionally by the Middle Jurassic-Early Cretaceous El Quemado Complex. The importance of this finding resides in the magnitude of the recognized sequence, with clear base and top. We propose to reunite these clastic deposits in a new lithostratigraphic unit, El Bello Formation. The type-section is located in the Argentina-Chile border, next to the Mayer River and close to Puesto El Bello. The sedimentites are constituted by polymictic conglomerates and fine- to medium-grained sandstones, with subordinate volcaniclastic sandstones. The beds are coarsening-upward, and they compose a thinning-upward sequence. The conglomerate fraction shows crude, planar and parallel stratification, while sandstones are well laminated. This unit was formed in a fluvial environment, where alluvial fans prevailed. They were the first infill in a hemigraben basin, and they would have been deposited in the first stages of the extension that would later lead to the widespread Jurassic regional volcanism. Its age has not been precisely determined, but on-going palaeomagnetic studies point to an Early Jurassic age for the magnetic remanence. We propose to include into this unit several comparable deposits, described by other authors in the cordilleran region of Santa Cruz province.

Palabras clave : El Bello Formation; Mesozoic; Patagonia; Extensión.

        · resumen en Español     · texto en Español     · Español ( pdf )

 

Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons