Characterization and space–time distribution of Plio-Quaternary volcanism NE of Caldas, Colombia

In the tectonically active NW corner of South America, our investigations have revealed the presence of at least 28 monogenetic volcanic structures within Colombia's Central Cordillera, NE of the currently active polygenetic volcanoes. Termed the Northeast Caldas Monogenetic Volcanic Field (NCMVF), this comprises small-volume magmatic and phreatomagmatic structures whose spatial distribution is mainly controlled by the NNE-trending Palestina and Río Dulce fault systems. Combined 40 Ar/ 39 Ar and 14 C geochronological datasets indicate ages ranging from 3.5 ± 0.2 Ma to 17 767 ± 253 years cal BP. Individual volcanic structures within this field mostly correspond to lava domes, some of them with associated deposits of phreatomagmatic nature, maar–diatreme and some monogenetic composite edifices such as dome complexes that have had at least two distinct eruptive activities separated by thousands of years. Whole-rock composition ranges from 58.9 to 74.9 wt% SiO 2 and 5–7.4 wt% alkalis, alongside a geochemical trace element signature akin to subduction-related arcs, and consistent with the geochemistry of neighbouring polygenetic volcanoes. This paper presents volcanological descriptions of felsic monogenetic volcanoes in the NCMVF, as well as new ages obtained, which could indicate that the volcanic field is active. This finding provides important knowledge to understand this type of volcanism and its tectonic setting, as well as for volcanic hazard assessment in Colombia.