BABLON , Mathilde

Des forages IODP réalisés dans le bassin de Panamá, au large de l'Équateur, ont mis en évidence une trentaine de niveaux de cendres volcaniques enregistrées dans les séquences sédimentaires marines. Ces cendres ont été émises lors d'éruptions explosives majeures qui ont eu lieu au cours des derniers 10 Ma. Dans la Cordillère nord andine, le...

We compare K-Ar ages obtained on groundmass and plagioclase from lava domes that erupted after flank collapse events in the Lesser Antilles and Ecuador. All samples contain plagioclase with distinct zoning patterns, as well as inclusion-rich zones, that reveal one or more crystal resorption events due to rapid temperature changes. In these...

The Cotacachi-Cuicocha volcanic complex (CCVC), located to 60-70 km from Quito, is part of the volcanic front (Western Cordillera) of the Ecuadorian Andes. This complex is located inside the new Imbabura UNESCO Geopark, and it is surrounded by several highly populated cities like Cotacachi and Quiroga.New geochemical, petrological and...

Despite the multiple efforts to understand the temporal evolution of the Ecuadorian Volcanic Arc, the evolutionary history of the oldest volcanic edifices remained poorly studied. The Paris-Saclay University, the Instituto Geofísico of the Escuela Politécnica Nacional and the French Instituto de Investigación para el Desarrollo carried out an...

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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Based on new geological data and analysis of Digital Elevation Model, we update the active fault mapping and determine earthquake geology hints of a section of a major crustal active fault system of continental Ecuador, namely the Pallatanga Fault to its junction with the Cosanga Fault, a part of the continental-scale dextral shear zone between...

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...

International audience

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...

Extensive fieldwork at the Cotacachi-Cuicocha Volcanic Complex (CCVC, North of Ecuador) resulted in a new collection of geological data including cartography, chronology, petrography, geochemistry, and morphology. This volcanic complex is formed by a central volcano (Cotacachi: 4939 m asl, current bulk volume of 56 ± 4 km3), several peripheral...

Based on new geological data and the analysis of a 4 m spatial resolution Digital Elevation Model (DEM), we provide a detailed and comprehensive description of section of the Chingual Cosanga Pallatanga Puna Fault System, a major active fault system in Ecuador. This work allows estimating new slip rates and large earthquakes parameters...

The volcanism of the Northern Andes is characterized by an intense Plio-Quaternary activity, whose onshore deposits have covered older products associated with the early development of the arc. To improve our knowledge of the largest explosive eruptions that occurred in the Northern Andean arc since the Miocene, we analyzed tephra layers...

The volcanism of the Northern Andes is characterized by an intense Plio-Quaternary activity, whose onshore deposits have covered older products associated with the early development of the arc. To improve our knowledge of the largest explosive eruptions that occurred in the Northern Andean arc since the Miocene, we analyzed tephra layers...

L'identification de la source volcanique de niveaux de cendres (téphras) préservés dans les sédiments marins apporte des informations essentielles pour étudier l'impact des éruptions majeures passées et pour contraindre temporellement les séquences sédimentaires. Les sources volcaniques sont généralement déduites de corrélations terre-mer...

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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...