Geomorphological evolution and chronology of the eruptive activity of the Columba and Cuevas volcanoes (Campo de Calatrava Volcanic Field, Ciudad Real, Central Spain)

摘要

In this study we analyze the geomorphological evolution and chronology of the eruptive phases of the Columba and Cuevas volcanoes (Campo de Calatrava Volcanic Field, Central Spain). These are two cinder cones located at the margins of the Jabalon River valley, between the localities of Granatula de Calatrava and Aldea del Rey (Ciudad Real). In order to generate geomorphological map, we conducted fieldwork and photointerpretation of aerial images, in addition to morphometric and volcanostratigraphic analyses aimed at correlating the volcanic deposits and fluvial terraces of the Jabalon River. Finally, we applied OSL (optically stimulated luminescence) dating to obtain the age of fluvial deposits affected by both volcanoes, plus radiocarbon dating to the organic matter of a paleosoil located between the Columba volcano deposits. The results provide a maximum age of 75.16 +/- 4.9 ka for the formation of the Cuevas volcano. Moreover, the Columba volcano began its activity with a Strombolian phase around 33.9 +/- 236 ka BP, followed by a long period of inactivity between 24.9 and 232 ka and 14-13.5 ka BP in which the aforementioned paleosoil formed. Subsequently, the eruptive activity resumed with a phreatomagmatic phase followed by another Strombolian phase, in which a lava flow was emplaced crossing and damming the Jabal& River, thus forcing the deposition of a 9 m thick fluvial terrace above it, at about 6.27 +/- 4.28 ka. The Columba volcano is a good example of polycyclic eruptive behavior in a monogenetic volcanic field, whose last eruption occurred between 14 and 6.2 ka ago. The interaction between volcanic and fluvial processes was responsible for the morphological evolution of the area, the study of which has been crucial to determine the evolution of the eruptive activity, its morphological results, and the relative chronologies. (C) 2019 Elsevier B.V. All rights reserved.