Bablon M. auteur aut IRD Quidelleur X. auteur aut IRD Samaniego Pablo auteur aut IRD Le Pennec Jean-Luc auteur aut IRD Santamaria S. auteur aut IRD Liorzou C. auteur aut IRD Hidalgo S. auteur aut IRD Eschbach B. auteur aut IRD text journalArticle eng text/pdf born digital access In the northern Andes, the Ecuadorian arc presents a large number of Quaternary volcanoes, spread over a rather restricted area. The origin of this volcanic clustering is not well understood, and only a few chronological data older than the Holocene are available in northern Ecuador to document the arc development stages. In this study, we present new K-Ar ages obtained on lava flow and pumice samples for Cushnirumi, Mojanda, Fuya Fuya, Imbabura, Cubilche, and Cusin volcanoes, located about 40 km north of Quito, the Ecuador's capital city. Our results show that the volcanic activity in the northern part of the Ecuadorian arc started at least at 1 Ma and that construction of volcanoes mainly occurred during the last 500 ka. Together with the radiometric data, numerical reconstructions of the paleomorphology of the volcanoes are used to estimate the volume of emitted magmas and the amount of eroded material in order to quantify their eruptive and erosion rates. Emission rates of Ecuadorian volcanoes range between < 0.2 and 3.6 +/- 2.1 km(3)/kyr. Highest rates are obtained for volcanoes constructed over time periods shorter than 100 kyr by sporadic eruptive pulses, whereas lowest rates are calculated over longer periods that include quiescence phases. Erosion rates range between 0.02 +/- 0.01 and 0.14 +/- 0.09 km(3)/kyr and highlight that volcanic edifices whose activity ended recently are rapidly dismantled by physicochemical processes. Finally, the spatial distribution of Quaternary volcanoes as well as the spatio-temporal evolution of lava geochemistry may reflect the progressive influence of the Carnegie Ridge at depth. Graphical abstract specialized Ecuador K-Ar dating Volcanic arc Eruptive rates Erosion Volumes EQUATEUR ANDES 066 82 1 art. 11 [23 p.] 2020 0258-8900 https://www.documentation.ird.fr/hor/fdi:010077917 10.1007/s00445-019-1346-1 0258-8900 [F B010077917] https://www.documentation.ird.fr/hor/fdi:010077917 https://www.documentation.ird.fr/intranet/publi/2020/03/010077917.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2020-05-18 2025-02-24 fdi:010077917 fre