SciELO - Scientific Electronic Library Online

 
vol.28 issue1Talc mineralization related to the ultramafic bodies of the Río de Las Tunas belt, Frontal Cordillera of Mendoza provinceVolcanism and associated mineralization in the Cerro Tiporco area, San Luis province, Argentina 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

BENEDINI, Leonardo  and  GREGORI, Daniel. The Garamilla Formation: Lower Jurassic volcanic eventin western Comarca Nordpatagónica, Río Negro province, Argentina. Ser. correl. geol. [online]. 2012, vol.28, n.1, pp. 131-144. ISSN 1666-9479.

The Garamilla Formation cropping out at the western edge of the Nordpatagonian Region is composed by volcanic and pyroclastic rocks of andesites, dacíticas and rhyolitic compositions whose age extends from the Late Triassic to Early Jurassic. In the area of the puestos Quiñenao, Fuensalida and cañadones Mencué, Blancura and Currú Mahuida appears a sequence 800 m thick where three volcanic events were recognized. The first one consists of domes and rhyolitic lavas, as well as lava-like ignimbrites. The second is represented by dikes and andesitic to dacitic lava flows, lapilli-tuffs and eutaxitic lapilli-tuffs of dacitic composition. The third event is made up of tuffs, rheomorfic tuffs, lapilli-tuffs, volcanic breccias, lava flows and dikes. This unit forms a calc-alkaline series related to a subduction process. An U-Pb age of 185 ± 2 Ma (Pliesbachian) was obtained for the lapilli-tuffs lithofacies of the second volcanic event. These features allow correlation with the Lower Jurassic calc-alkaline volcanism developed in the Neuquén province.

Keywords : Garamilla Formation; Nordpatagonian Region; Jurassic magmatism; Argentina.

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