SciELO - Scientific Electronic Library Online

 
vol.63 número2Remoción en masa y colapso catastrófico de diques naturales generados en el frente orogénico andino (36º-38ºs): los casos Navarrete y Río Barrancas índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Articulo

Indicadores

  • No hay articulos citadosCitado por SciELO

Links relacionados

  • En proceso de indezaciónCitado por Google
  • No hay articulos similaresSimilares en SciELO
  • En proceso de indezaciónSimilares en Google

Bookmark


Revista de la Asociación Geológica Argentina

versión On-line ISSN 1851-8249

Resumen

MASSABIE, Armando C.; NESTIERO, Osvaldo E.  y  SANGUINETTI, Alicia S.. Cohesive breccias and microbreccias in quartzites in the Buenos Aires ranges: similitude, differences, and an approximation to their tectonic links. Rev. Asoc. Geol. Argent. [online]. 2008, vol.63, n.2, pp. 163-171. ISSN 1851-8249.

Quartzitic sandstones of the sierras Bayas Group in Sierras Septentrionales of Buenos Aires are studied. Outcrops of these deformed rocks are observed at sierras Bayas and Barker localities, where quartzitic sandstones from Precambrian units are present. These rocks are compared with similar fault breccias in Sierras Australes of Buenos Aires, which were develop in quartzitic rocks of several Paleozoic units of this region. At both regions, fault zones are subvertical layers with acute contacts on the wall rocks. An original sedimentary protolith is recognized in textures and structures preserved in all samples of Sierras Bayas. Sedimentary textures at Sierras Australes are obliterated by penetrative deformation in greenschists facies methamorphism and also show a metaquartzitic protolith. In both analyzed regions, similar cataclastic textures are observed. All these breccias and microbreccias would be associated with a major extensional tectonic event of Jurassic - Cretaceous age, which could be related to the origin of Colorado and Salado extensional basins during the opening of the South Atlantic Ocean.

Palabras llave : Fault rocks; Sierras de Buenos Aires; Breccias; Microbreccia cohesive.

        · resumen en Español     · texto en Español     · pdf en Español