Abstract

FRANCO-RAMOS, Osvaldo; VAZQUEZ-SELEM, Lorenzo; ZAMORANO-OROZCO, José Juan  and  VILLANUEVA-DIAZ, José. Edad, dinámica geomorfológica y tipología de barrancas en el sector norte del volcán Popocatépetl, México. Bol. Soc. Geol. Mex [online]. 2017, vol.69, n.1, pp.1-19. ISSN 1405-3322.

This study investigates the age and morphodynamics of ravines (barrancas) developed in late Pleistocene to Holocene pyroclastic deposits on the northern slope of Popocatépetl volcano by means of stratigraphic analyses, 14C dating and dendrogeomorphologic methods. On this basis, we propose a typology for the ravines according to their origin, age and geomorphological dynamics. The oldest and most stable ravines formed in pyroclastic deposits emplaced at ~17000 cal. yr B.P.; their slopes became relatively stable by ~6000 cal. yr B.P., were mantled by tephra from the 5600 - 5,900 and ~1100 cal. yr B.P. Plinian eruptions of Popocatépetl, and have been inactive for at least 200 yr, despite their young appearance. The younger and more active ravines were excavated in pyroclastic deposits from the last Plinian eruption (~1100 cal. yr B.P), during the final stages of the eruption or shortly thereafter. Today these ravines are characterized by unstable conditions and are episodically exposed to lahars, as is the case of the Huiloac ravine.

Keywords : Popocatépetl volcano; ravines; dendrogeomorphology; post-eruptive erosion.