RT Journal Article
T1 An extensive K-bentonite as an indicator of a super-eruption in northern Iberia 477 My ago
A1 Gutiérrez-Alonso, Gabriel
A1 Gutiérrez Marco, Juan Carlos
A1 Fernández Suárez, Javier
A1 Bernárdez Rodríguez, Enrique
A1 Corfu, F.
A1 López Carmona, Alicia
AB Zircon and monazite ID-TIMS U-Pb dating of four Lower Ordovician altered ash-fall tuff beds (K-Bentonites) in NW Iberia provided coetaneous ages of 477.5±1, 477±1.3 Ma, 477.2±1.1 Ma and 477.3±1 Ma, with a pooled concordia age of 477.2±0.74 Ma. A conservative estimation of the volume and mass of the studied K-bentonite beds (using data from the Cantabrian Zone) returns a minimum volume for the preserved deposits of ca. 37.5 km3 (Volcanic Explosivity Index - VEI = 6, Colossal). When considering other putative equivalent beds in other parts of Iberia and neighbouring realms the volume of ejecta associated to this event would make it reach the Supervolcanic-Apocalyptic status (VEI=8, >1000 km3). Contrary to most cases of this kind of gargantuan eruption events, the studied magmatic event took place in relation to continental margin extension and thinning and not to plate convergence. We speculate that a geochronologically coincident large caldera event observed in the geological record of NW Iberia could be ground zero of this super-eruption.
PB IOP Publishing
SN 1755-1307, ESSN: 1755-1315
YR 2019
FD 2019
LK https://hdl.handle.net/20.500.14352/13675
UL https://hdl.handle.net/20.500.14352/13675
LA eng
NO Ministerio de Economía y Competitividad (MINECO)
NO Russian Federation
DS Docta Complutense
RD 1 may 2024