Geochronological evolution of the potentially active Iliniza Volcano (Ecuador) based on new K-Ar ages

The youngest volcanism of the Ecuadorian Volcanic Front (Western Cordillera) is mainly dominated by highly explosive events, including growth and violent destruction lava domes, formation thick pyroclastic sequences. Deposits associated with such eruptive dynamics have been identified at Iliniza, a compound volcano located in Western Cordillera poorly defined evolutionary history. We present first K-Ar ages Iliniza combined stratigraphic data, numerical reconstructions, geochemical analyses, providing new perspective on its evolution. Our results show that much younger than previously proposed. twin-peaked shape result superposition two andesitic to dacitic stratovolcanoes. (1) North (NI) edifice was constructed successions an intermediate satellite vent, showing short range effusive activity between 123 ± 6 116 2 ka. (2) South (SI) began construction through Lower SI stage when massive lavas dated ~45 ka formed basal cone. During Upper stage, uppermost part this destroyed Jatuncama phase (VEI 5) leaving 30–40 m-thick ignimbrite sequence. subsequent extrusion several domes reconstructed summit around 35 Terminal corresponds emission 31 4 25 3 extended into Late Pleistocene Holocene Tishigcuchi dome, Pongo flow Based proposed history, we suggest revised volcanic hazard assessment potentially active required.