HIDALGO , Silvana

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...

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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...

International audience

The Billecocha plateau (4000 m a.s.l.) lies in the high elevation Ecuadorian Andes volcanic arc. It overhangs by 2000 m above the interandean valley. Both the plateau and surrounding volcanoes are heavily affected by active faulting characterized by straight, sharp and discontinuous scarps within a 6 km wide and 24 km long corridor. Contrasting...

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...

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...

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...