Eruptive chronology of the late Miocene Peñuela Volcanic complex formed during the early stage of activity of the Trans-Mexican volcanic belt

The Peñuela Volcanic Complex is in the central part of the Trans-Mexican Volcanic Belt (TMVB). It consists of volcanic domes emplaced over marine sedimentary successions from the Upper Jurassic to Upper Cretaceous periods. In this paper, we present a new geological map, stratigraphic, structural, and geochemical data of these domes. The Peñuela Volcanic Complex is made of two successions of dacitic and rhyolitic calc-alkaline rocks. New UPb zircon ages of these successions yielded 11.72 ± 0.61 and 10.71 ± 0.19 Ma (late Miocene). These ages correlate with the early stages of volcanic activity in the eastern sector of the TMVB. Volcanism in the region has been characterized by the emplacement of different successions of rocks ranging from andesitic to dacitic and rhyolitic, under a NW-SE oriented structures that occurred during the Miocene. The geochemical and petrographic analysis shows evidence of magmatic differentiation through a combination of assimilation and different degrees of fractional crystallization. These results suggest that the Peñuela Volcanic Complex is part of a broader Miocene magmatic episode in the TMVB, shaped by crustal assimilation, tectonic extension, and regional-scale migration of volcanic activity.