The eruptive chronology of the Carihuairazo volcano (Ecuador): Recurrent sector collapses of a Middle Pleistocene stratovolcano of the northern andes
Autor: | Pablo Samaniego, Jorge Ordóñez, Mathilde Bablon, Minard L. Hall, Xavier Quidelleur, Pierre Lahitte, Santiago Santamaria, Céline Liorzou |
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Přispěvatelé: | Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Instituto Geofisico - Escuela Politecnica Nacional (IGEPN), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Geo-Ocean (GEO-OCEAN), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
Rok vydání: | 2022 |
Předmět: |
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics
Carihuairazo [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Unspiked K-Ar dating [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Debris avalanche deposits Geology Ecuador [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology Eruptive chronology Earth-Surface Processes |
Zdroj: | Journal of South American Earth Sciences Journal of South American Earth Sciences, 2022, pp.103865. ⟨10.1016/j.jsames.2022.103865⟩ |
ISSN: | 0895-9811 |
Popis: | International audience; 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 fieldwork on both the proximal flanks of the volcano and the medial-to-distal deposits of the nearby Ambato basin, as well as a large dataset of geochronological (40K-40Ar, 14C) and geochemical (major and trace element) data. The Basal Carihuairazo edifice is mainly composed of an andesitic lava flow succession dated at 230-200 ka. The resulting edifice suffered a first sector collapse that was responsible for a relatively large (4 ± 1 km3) debris avalanche deposit (DAD-1) that covers the entire Ambato basin. This event occurred between 206 ± 4 and 216 ± 5 ka. Then, Carihuairazo started a succession of construction (Intermediate and Terminal lava flow successions) and destruction stages lasting about 50 ky (i.e., from 200 to 150 ka), which are composed by thick block-and-ash flow deposits (L- and U-BAFD) and debris avalanche deposits (DAD-2). This volcanic succession is recorded in the Ambato basin, interlayered with several tephra fallout deposits (TFD-1 to -4) whose source is the neighbouring Huisla-Mulmul volcanic complex. The current morphology of Carihuairazo results from two additional sector collapses (DAD-3 and -4) that occurred during the past 40-50 ka, i.e., following a long period (at least 100 ka) without volcanic activity. We stress these debris avalanches were not related with magmatic activity. Samples from the Carihuairazo volcano defines a medium-K magmatic trend composed of andesites and dacites with a mineral assemblage of plagioclase, amphibole, ortho- and clino-pyroxene, and Fe–Ti oxides. The evolution of the Carihuairazo edifice, recorded in the medial-distal deposits of the Ambato basin, represents a unique example in the Ecuadorian arc of an edifice that experienced successive destruction and construction stages during a major part of its volcanic history. |
Databáze: | OpenAIRE |
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