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Université de Fribourg

Ollo de Sapo Cambro-Ordovician volcanics from the Central Iberian basement—A multiphase evolution

Raumer, Jürgen F. von ; Stampfli, Gérard M.

In: Terra Nova, 2018, vol. 30, no. 5, p. 350–358

The Cambro-Ordovician rhyodacitic to dacitic volcanics from the Central Iberian basement, currently known as Ollo de Sapo (toads eye), have been reported as a specific group of felsic porphyritic rocks with blue quartz and large phenocrysts of K- feldspar, in a partly vitreous or fine-grained matrix. Interpreted to form Cambro- Ordovician volcanic domes, they are accompanied by tuffs,...