Crummy, J, Savov, IP, Navarro-Ochoa, C et al. (2 more authors) (2014) High-K Mafic Plinian Eruptions of Volcan de Colima, Mexico. Journal of Petrology, 55 (11). 2155 - 2192. ISSN 0022-3530
Abstract
The last Plinian-type eruption of Volcán de Colima, Mexico, occurred in 1913; this resulted in the removal of the top 100 m of the edifice and the deposition of a tephra layer that blanketed the slopes of the Colima Volcanic Complex (CVC). Road-cuts on the flanks of the nearby Nevado de Colima edifice expose pre-1913 air-fall tephra, pyroclastic flow and ash-rich surge deposits resulting from numerous highly explosive events throughout the Holocene. The majority of the pumice and scoria fallout deposits are medium-K subalkaline basaltic andesite and andesite in composition, defining a clear major element differentiation trend. In contrast, three newly discovered scoria fallout deposits are high-K subalkaline, transitional to alkaline, basaltic andesite in composition and are characterized by the presence of phlogopite; these deposits have high MgO (up to 7·9 wt %), K2O (up to 2·6 wt %) and P2O5 (up to 0·67 wt %) contents. They are also strongly enriched in fluid- and melt-mobile large ion lithophile elements (LILE; Rb, Ba, K, Sr and Th) and light REE (LREE; La, Ce, Pr and Nd) relative to the majority of the Colima tephra fallout deposits. Strontium and Nd isotope systematics reveal that the high-K mafic scoria have more radiogenic Sr (87Sr/86Sr = 0·70365–0·70408) and less radiogenic Nd (143Nd/144Nd = 0·51279–0·51294) compared with the majority of the subalkaline tephras (87Sr/86Sr = 0·70338–0·70371 and 143Nd/144Nd = 0·51290–0·51295). Two-component mixing models, using whole-rock geochemical data, indicate the importance of magma mixing in the petrogenesis of the Colima magmas, with addition of up to 50% by volume of an alkaline mafic magma component in the most potassic magmas. This is supported by mineral chemistry and textural data, which reveal multiple episodes of decompression and magma mingling within a shallow crustal magma storage region. The presence of these potassic tephra fall deposits among the otherwise prevailing medium-K subalkaline stratigraphy indicates that pulses of K-rich alkaline mafic magmas periodically enter the CVC plumbing system on timescales of a few thousand years and may trigger Plinian explosive eruptions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author 2014. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 Dec 2014 14:10 |
Last Modified: | 07 Dec 2022 14:57 |
Published Version: | http://dx.doi.org/10.1093/petrology/egu053 |
Status: | Published |
Publisher: | Oxford University Press (OUP) |
Identification Number: | 10.1093/petrology/egu053 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:81443 |