Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador)
Abstract The Tierra Blanca (TB) eruptive suite comprises the last four major eruptions of Ilopango caldera in El Salvador (≤45 ka), including the youngest Tierra Blanca Joven eruption (TBJ; ∼106 km3): the most voluminous event during the Holocene in Central America. Despite the protracted and produc...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2021-05-01
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| Series: | Geochemistry, Geophysics, Geosystems |
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| Online Access: | https://doi.org/10.1029/2020GC009507 |
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| author | A. Cisneros de León A. K. Schmitt S. Kutterolf J. C. Schindlbeck‐Belo W. Hernández K. W. W. Sims J. Garrison L. B. Kant B. Weber K.‐L. Wang H.‐Y. Lee R. B. Trumbull |
| author_facet | A. Cisneros de León A. K. Schmitt S. Kutterolf J. C. Schindlbeck‐Belo W. Hernández K. W. W. Sims J. Garrison L. B. Kant B. Weber K.‐L. Wang H.‐Y. Lee R. B. Trumbull |
| author_sort | A. Cisneros de León |
| collection | DOAJ |
| description | Abstract The Tierra Blanca (TB) eruptive suite comprises the last four major eruptions of Ilopango caldera in El Salvador (≤45 ka), including the youngest Tierra Blanca Joven eruption (TBJ; ∼106 km3): the most voluminous event during the Holocene in Central America. Despite the protracted and productive history of explosive silicic eruptions at Ilopango caldera, many aspects regarding the longevity and the prevailing physicochemical conditions of the underlying magmatic system remain unknown. Zircon 238U‐230Th geochronology of the TB suite (TBJ, TB2, TB3, and TB4) reveals a continuous and overlapping crystallization history among individual eruptions, suggesting persistent melt presence in thermally and compositionally distinct magma reservoirs over the last ca. 80 kyr. The longevity of zircon is in contrast to previously determined crystallization timescales of <10 kyr for major mineral phases in TBJ. This dichotomy is explained by a process of rhyolitic melt segregation from a crystal‐rich refractory residue that incorporates zircon, whereas a new generation of major mineral phases crystallized shortly before eruption. Ti‐in‐zircon temperatures and amphibole geothermobarometry suggest that rhyolitic melt was extracted from different storage zones of the magma reservoir as indicated by distinct but synchronous thermochemical zircon histories among the TB suite eruptions. Zircon from TBJ and TB2 suggests magma differentiation within deeper and hotter parts of the reservoir, whereas zircon from TB3 and TB4 instead hints at crystallization in comparatively shallower and cooler domains. The assembly of the voluminous TBJ magma reservoir was also likely enhanced by cannibalization of hydrothermally altered components as suggested by low‐δ18O values in zircon (+4.5 ± 0.3‰). |
| first_indexed | 2024-03-11T12:58:58Z |
| format | Article |
| id | doaj.art-e4ab586cc3e640b98a5920382182cb37 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:58:58Z |
| publishDate | 2021-05-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-e4ab586cc3e640b98a5920382182cb372023-11-03T16:55:31ZengWileyGeochemistry, Geophysics, Geosystems1525-20272021-05-01225n/an/a10.1029/2020GC009507Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador)A. Cisneros de León0A. K. Schmitt1S. Kutterolf2J. C. Schindlbeck‐Belo3W. Hernández4K. W. W. Sims5J. Garrison6L. B. Kant7B. Weber8K.‐L. Wang9H.‐Y. Lee10R. B. Trumbull11Institut für Geowissenschaften Universität Heidelberg Heidelberg GermanyInstitut für Geowissenschaften Universität Heidelberg Heidelberg GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel SFB574 Kiel GermanyInstitut für Geowissenschaften Universität Heidelberg Heidelberg GermanyObservatorio Ambiental Ministerio de Medio Ambiente y Recursos Naturales San Salvador El SalvadorDepartment of Geology and Geophysics University of Wyoming Laramie WY USADepartment of Geosciences and Environment California State University Los Angeles CA USADepartment of Geology and Geophysics University of Wyoming Laramie WY USADepartamento de Geología Centro de Investigación Científica y de Educación Superior de Ensenada Ensenada BC MexicoInstitute of Earth Sciences Academia Sinica Taipei TaiwanInstitute of Earth Sciences Academia Sinica Taipei TaiwanGFZ German Research Centre for Geosciences Potsdam GermanyAbstract The Tierra Blanca (TB) eruptive suite comprises the last four major eruptions of Ilopango caldera in El Salvador (≤45 ka), including the youngest Tierra Blanca Joven eruption (TBJ; ∼106 km3): the most voluminous event during the Holocene in Central America. Despite the protracted and productive history of explosive silicic eruptions at Ilopango caldera, many aspects regarding the longevity and the prevailing physicochemical conditions of the underlying magmatic system remain unknown. Zircon 238U‐230Th geochronology of the TB suite (TBJ, TB2, TB3, and TB4) reveals a continuous and overlapping crystallization history among individual eruptions, suggesting persistent melt presence in thermally and compositionally distinct magma reservoirs over the last ca. 80 kyr. The longevity of zircon is in contrast to previously determined crystallization timescales of <10 kyr for major mineral phases in TBJ. This dichotomy is explained by a process of rhyolitic melt segregation from a crystal‐rich refractory residue that incorporates zircon, whereas a new generation of major mineral phases crystallized shortly before eruption. Ti‐in‐zircon temperatures and amphibole geothermobarometry suggest that rhyolitic melt was extracted from different storage zones of the magma reservoir as indicated by distinct but synchronous thermochemical zircon histories among the TB suite eruptions. Zircon from TBJ and TB2 suggests magma differentiation within deeper and hotter parts of the reservoir, whereas zircon from TB3 and TB4 instead hints at crystallization in comparatively shallower and cooler domains. The assembly of the voluminous TBJ magma reservoir was also likely enhanced by cannibalization of hydrothermally altered components as suggested by low‐δ18O values in zircon (+4.5 ± 0.3‰).https://doi.org/10.1029/2020GC009507Central AmericaGeochemistryOxygen isotopesSIMSU‐seriesZircon |
| spellingShingle | A. Cisneros de León A. K. Schmitt S. Kutterolf J. C. Schindlbeck‐Belo W. Hernández K. W. W. Sims J. Garrison L. B. Kant B. Weber K.‐L. Wang H.‐Y. Lee R. B. Trumbull Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador) Geochemistry, Geophysics, Geosystems Central America Geochemistry Oxygen isotopes SIMS U‐series Zircon |
| title | Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador) |
| title_full | Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador) |
| title_fullStr | Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador) |
| title_full_unstemmed | Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador) |
| title_short | Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador) |
| title_sort | zircon and melt extraction from a long lived and vertically extensive magma system underneath ilopango caldera el salvador |
| topic | Central America Geochemistry Oxygen isotopes SIMS U‐series Zircon |
| url | https://doi.org/10.1029/2020GC009507 |
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