English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/178012
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

The Ilopango caldera complex, El Salvador: Stratigraphic revision of the complete eruptive sequence and recurrence of large explosive eruptions

AuthorsSuñe-Puchol, I.; Aguirre-Díaz, Gerardo ; Pedrazzi, Dario ; Dávila-Harris, P.; Miggins, D.P.; Costa, Antonio; Ortega-Obregón, C.; Lacan, Pierre; Gutierrez, E.; Hernandez, Walter
KeywordsCentral America Volcanic Arc
Ignimbrite
Pull-apart graben
Stratigraphy of pyroclastic deposits
Tectonic-caldera
Issue DateApr-2019
PublisherElsevier
CitationJournal of Volcanology and Geothermal Research, 374: 100-119 (2019)
AbstractIlopango caldera erupted episodically at least 13 tuff-forming eruptions with a minimum estimate volume of 1–5 km 3 DRE per eruption, reaching up to 150 km 3 DRE for the first caldera-forming eruption. All tuffs are of dacitic-rhyolitic composition. The complete pyroclastic sequence spans a range in time from 1.785 to 0.0015 Ma, and based on stratigraphy and geochronology constraints can be divided into three formations: the Comalapa, Altavista and Tierras Blancas formations. In this work, we focus on the members of the newly described Altavista Formation (middle part of Ilopango caldera volcanic sequence), which consist of six consolidated pyroclastic deposits or tuffs. Each tuff corresponds to a specific eruption followed by a period of quiescence during which soil beds were developed on the deposits. The ages of the Altavista Formation ranges from 918 to 257 ka, based on new 40 Ar/ 39 Ar, U/Pb-zircon, and U/Th-zircon analyses. The tuffs of this formation show similar characteristics in mineralogy and composition. They are calcalkaline, rhyodacitic tuffs, with plagioclase, clinopyroxene, and hornblende. From field mapping and descriptions of the deposits, we have inferred the eruptive styles that include pumice fallouts, pyroclastic density currents and also hydromagmatic explosions. The common vent in all tuffs was the Ilopango caldera and each member of the Altavista Formation could correspond to a caldera collapse event, except for one of the six eruptions. The volume of each member was estimated to be >30 km 3 DRE, which is the same order of magnitude than that estimated for the Tierra Blanca Joven (TBJ) eruption at about 1,500 B. P, and smaller than those of the ignimbrites of the Comalapa Formation, the first three members of the Ilopango caldera reported previously. The tuffs of the Altavista Formation are visible up to 15–20 km away from the caldera's topographic margin. The recurrence interval of large explosive events at the Ilopango caldera was established by integrating the stratigraphic and geochronologic data of all 13 ignimbrites and pumice fallouts erupted from Ilopango caldera since the first one at 1.78 Ma to the last explosive event (TBJ). © 2019 Elsevier B.V.
Publisher version (URL)https://doi.org/10.1016/j.jvolgeores.2019.02.011
URIhttp://hdl.handle.net/10261/178012
DOI10.1016/j.jvolgeores.2019.02.011
ISSN0377-0273
Appears in Collections:(ICTJA) Artículos
Files in This Item:
File Description SizeFormat 
Pedrazzi_Journal_of_Volcanology_and_Geothermal_Research_374_100–119_postprint.pdf Embargoed until December 30, 201917,02 MBAdobe PDFThumbnail
View/Open    Request a copy
Show full item record
Review this work
 


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.