SciELO - Scientific Electronic Library Online

 
vol.41 número3Cronología y geología de una asociación de mamíferos del Mioceno Temprano en el Norte de América del Sur, cerro La Cruz (Formación Castillo), Estado Lara, Venezuela: implicaciones para las hipótesis del 'cambio del curso del río Orinoco'Origen y emplazamiento del Domo Tinto, volcán Guallatiri, Norte de Chile índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados

Revista

Articulo

Indicadores

Links relacionados

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

Compartir


Andean geology

versión On-line ISSN 0718-7106

Resumen

ROSSEL, Pablo et al. The Upper Jurassic volcanism of the Río Damas-Tordillo Formation (33°- 35.5°S): Insights on petrogenesis, chronology, provenance and tectonic implications. AndGeo [online]. 2014, vol.41, n.3, pp.529-557. ISSN 0718-7106.  http://dx.doi.org/10.5027/andgeoV41n3-a03.

The uppermost Jurassic continental and volcanic deposits of the Río Damas-Tordillo Formation represent an interval of intense continental deposition within the Jurassic to Early Cretaceous dominantly marine environment of the Mendoza-Neuquén back-arc basin. Stratigraphic and geochronological data indicate that progressive emersion of the arc and forearc domain, disconnecting the back-arc region from the Pacific Ocean, occurred during occurred during the Late Jurassic and probably the Early Cretaceous (~160-140 Ma). This change in the margin configuration induced a marine regression and the subsequent deposition of continental material in the back-arc basin. The most likely source of the sediments would have been the Jurassic arc, located west of the back-arc basin. The maximum depositional age of 146.4±4.4 Ma obtained from a red sandstone immediately below volcanic rocks confirms recent Tithonian maximum depositional ages assigned to the Río Damas-Tordillo Formation, and suggests that the volcanic rocks, overlain by marine fossiliferous Tithoninan-Hauterivian sequences, should have erupted within a short time span during the Late Jurassic. Volcanism was probably facilitated by the presence of extensional structures related to the formation of the back-arc basin. Elemental and isotopic data, along with forward AFC models, suggest a depleted sub-arc asthenospheric mantle source for the volcanic rocks and the fractionation of olivine and plagioclase, along with small volumes of lower crust assimilation, as the main processes involved in the magmatic evolution. It is not possible to establish a different source and petrogenetic conditions for the Río Damas-Tordillo Formation and the magmatism in the arc domain located further west, at the present-day Coastal Cordillera.

Palabras clave : Jurassic; Volcanism; Central Chile; Detrital zircons; Isotopes.

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

 

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