Stratigraphy and K-Ar ages of the Diego Hernández wall and their significance on the Las Cañadas Caldera formation (Tenerife, Canary Islands)

The Las Canadas Caldera corresponds to a volcanic caldera formed after a long period of explosive activity. The structural and lithological variations which can be observed in the caldera wall make clear the complexity of the original Las Canadas Edifice in which different eruptive centres existed. The stratigraphic and structural reconstruction of the Las Canadas Caldera indicates that the Diego Hernández wall, located at the eastern side of the caldera wall, comprises the youngest pre-caldera deposits. Determination of their K-Ar ages has provided the maximum age for the formation of the Las Canadas caldera. The results are internally consistent with stratigraphic relationships and allow two pre-caldera volcanic cycles in the Diego Hernández wall to be differentiated in accordance with geological evidence. The first cycle shows imprecise age limits. The second cycle ranges from 0.35 to 0.17 Ma. This upper pre-caldera age suggests that the Las Canadas caldera and the Teide-Pico Viejo were formed more recently than was previously assumed.