SciELO - Scientific Electronic Library Online

 
vol.28 issue1Gondwanic pyroclastic deposits in southern Sierra de Varela, San Luis province: petrography and geochemistryTertiary mafic volcanism of the Jujuy Puna, the Cerros Negros de Jama author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Article

Indicators

  • Have no cited articlesCited by SciELO

Related links

  • On index processCited by Google
  • Have no similar articlesSimilars in SciELO
  • On index processSimilars in Google

Bookmark


Serie correlación geológica

On-line version ISSN 1666-9479

Abstract

GREGORI, Daniel A  and  STRAZZERE, Leonardo. Eruptiveand inter-eruptivestages in theChoiyoi Group of the Mendoza Precordillera. Ser. correl. geol. [online]. 2012, vol.28, n.1, pp. 33-50. ISSN 1666-9479.

In the area of the Cerro Siete Colores, located east of Uspallata, in the Mendoza Precordillera, appears a set of volcanic and sedimentary rocks which were assigned to the acidic section of the Choiyoi Group. The sedimentary rocks reach 300 m thickness. The volcanic rocks represent a highly explosive period that includes two eruptive events with large volumes of rock, being the first generated by a single-surge current followed by quasi-steady phase sustained currents. The second eruptive event represented by highly-welded ignimbrites, can be correlated with the emplacement of domes of late Lower Permian age. It shows a considerable areal reduction compared to the first event, as well as a generalized stage of subsidence. The first inter-eruptive sedimentary event is made up by conglomerates, sandstones, limestones and mudstones that represent dense flows, lahars, lagoon and river environments. The latter have the largest areal development and are constituted by limestones where stromatolite, verme and palynomorph remains were recognized. The second inter-eruptive event is almost exclusively represented by lagoon systems and was probably larger than the first. The morphology and the thickness of the depocenters were conditioned by the previous structure of the Bonilla (Cambro-Ordovician) and Santa Elena (Carboniferous) formations, as well as by a widespread system of faulting during the last volcanic events of the Choiyoi Group.

Keywords : Choiyoi Group; Mendoza Precordillera; Eruptive and inter-eruptive stages; Lower Permian; Argentina.

        · abstract in Spanish     · text in Spanish     · pdf in Spanish