LIORZOU , Céline

The eruptive chronology of arc volcanoes consists of construction stages usually punctuated by large collapse events affecting the edifice. In this paper, we reconstruct the eruptive chronology of Carihuairazo volcano, a Middle Pleistocene edifice from the Ecuadorian segment of the Andean Northern Volcanic Zone. This study is based on extensive...

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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...

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New K-Ar ages obtained on juvenile pumice glass shards indicate that the Chalupas ignimbrite, one of the main Pleistocene tephra markers of the Ecuadorian arc, was emplaced at 216 ± 5 ka. Morphology and major and trace element contents of the glass shards are similar to those of ash layers from deep-sea cores and allow correlation between...

International audience

Identifying the sources of distal tephra in marine sediments or polar ice provides clues on the dynamic and large-scale impact of major volcanic eruptions. However, determination of the volcanic source of distal tephra is challenging due to size-dependent fractionation during atmospheric transport that modifies the mineral, chemical and even...

Correlations between marine distal ash layers and continental proximal volcanic deposits constitute a strong tool to investigate the eruptive chronology of an active volcanic arc, to constrain the detailed stratigraphy of the marine sediments, as well as help constraining the magnitude of some large explosive eruptions.In the Andean Northern...

L'arc volcanique nord andin, induit par le plongement de la plaque océanique Nazca sous le continent sud-américain, s'étend de la zone centrale de l'Équateur à la zone centrale de la cordillère colombienne. En Équateur, l'arc est composé de plus de 80 édifices volcaniques actifs durant le Quaternaire, ce qui correspond à la plus forte densité...

Tephra layers preserved in marine sediments are strong tools to study the frequency, magnitude and source of past major explosive eruptions. Thirty-seven volcanoes from the Ecuadorian and Colombian arc, in the northern Andes, experienced at least one eruption during the Holocene. The volcanic hazard is therefore particularly high for the...

Along active margins, large magnitude earthquakes induce submarine slope instabilities, generating turbidite deposits and debris flows. These catastrophic events are recorded in the stratigraphy from the slope basins to the subduction trench. These sedimentary records provide a unique opportunity to time-extend local seismic catalogs, and their...

Major eruptions in the Andes are mainly characterized by the emission of large volumes of gas and volcanic ash. The plume may reach the stratosphere and be transported by winds. In Ecuador, the prevailing winds are westward, and the volcanic ash, also called tephra, is transported towards the Pacific Ocean. Vallejo (2011) studied tephra layers...