Mecanismos de emisión, transporte y depósito de las Ignimbritas Roque Nublo (Gran Canaria, Islas Canarias)

Abstract

The Roque Nublo non-welded, lithic rich, ignimbrites are the most characteristic deposits of the second magmatic cycle (Pliocene in age) on Gran Canaria. They originated from vulcanianphreatom agmatic type eruptions wich caused rapid and significant erosion of vents thus in corporating a high proportion of lithic clasts into the eruption columns. These rapidly became too dense to be sustained vertically and collapsed nearly instantaneously causing the formation of high-density pyroclastic flows. The pyroclastic flows were confined to the radial network of paleovalleys at the flanks of the Roque Nublo stratovolcano during the main part of their emplacement. In distal areas, close to the coast line where these paleovalleys opened, most of the pyroclastic flows expanded and formed different small-volume flow units