Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt
Mineral Chemistry, and major and trace element variations of the basalts from Klyuchevskoy, the world's most active island are volcano, are most consistently explained by the persistence of a non-steady state, erupting, recharging, and fractionating magma chamber in which fractionation of a par...
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1994
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fthighwire:oai:open-archive.highwire.org:petrology:35/1/1 2023-05-15T16:59:10+02:00 Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt KERSTING, ANNIE B. ARCULUS, RICHARD J. 1994-02-01 00:00:00.0 text/html http://petrology.oxfordjournals.org/cgi/content/short/35/1/1 https://doi.org/10.1093/petrology/35.1.1 en eng Oxford University Press http://petrology.oxfordjournals.org/cgi/content/short/35/1/1 http://dx.doi.org/10.1093/petrology/35.1.1 Copyright (C) 1994, Oxford University Press Articles TEXT 1994 fthighwire https://doi.org/10.1093/petrology/35.1.1 2013-05-27T06:37:50Z Mineral Chemistry, and major and trace element variations of the basalts from Klyuchevskoy, the world's most active island are volcano, are most consistently explained by the persistence of a non-steady state, erupting, recharging, and fractionating magma chamber in which fractionation of a parental high-MgO basalt melt produces high-Al 2 O 3 basalt. Although fractional crystallization is the dominant controlling mechanism, periodic recharge with a more primitive high-MgO basalt is also an important process contributing to the chemical evolution of the magmas. Hybrid basalts are the mixed product of high-Al 2 O 3 basalt recharged with high-MgO basalt. The lavas range in composition from high-MgO, low-Al 2 O 3 (∼ 12 wt. % MgO, 14 wt. % Al 2 O 3 ) to high-Al 2 O 3 , low-MgO (∼ 18 wt. % Al 2 O 3 , 4 wt. % MgO). The high-MgO lavas are characterized by phenocrysts of olivine (cores FO 90–80 and rims FO 85–75 ) with chromite inclusions [Cr/(Cr + Al)≥0.7], clinopyroxene (Wo 46–42 En 48–42 Fs 15–7 ), and the rare occurrence of orthopyroxene (En 72–70 ). All the phenocrysts are normally zoned and set in a groundmass of plagioclase, pigeonite, clinopyroxene, magnetite, � orthopyroxene. The high-Al 2 O 3 basalts contain plagioclase (An 85–55 ), olivine (Fo 80–65 ), clinopyroxene (Wo 45–30 En 50–38 Fs 23–11 ), � orthopyroxene (En 72–70 ) phenocrysts, that preserve both normal and reverse zoning in a groundmass of plagioclase, pigeonite, olivine, clinopyroxene, magnetite, � orthopyroxene. Hybrid basalts have characteristics of both high-MgO basalts and high-Al 2 O 3 basalts and preserve complicated normal-to-reverse, reverse-to-normal, and normally zoned phenocrysts. No hydrous minerals are present in any of the lavas. The varied basaltic magmas erupted from Klyuchevskoy are derived from a magma chamber(s) located near the base of the Kamchatka crust (pressures ∼ 0.5–0.9 GPa) and characterized by relatively high crystallization temperatures, some in excess of ∼1150�C. Under these conditions, the fractionation of a parental ... Text Kamchatka HighWire Press (Stanford University) Journal of Petrology 35 1 1 41 |
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Articles KERSTING, ANNIE B. ARCULUS, RICHARD J. Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt |
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Mineral Chemistry, and major and trace element variations of the basalts from Klyuchevskoy, the world's most active island are volcano, are most consistently explained by the persistence of a non-steady state, erupting, recharging, and fractionating magma chamber in which fractionation of a parental high-MgO basalt melt produces high-Al 2 O 3 basalt. Although fractional crystallization is the dominant controlling mechanism, periodic recharge with a more primitive high-MgO basalt is also an important process contributing to the chemical evolution of the magmas. Hybrid basalts are the mixed product of high-Al 2 O 3 basalt recharged with high-MgO basalt. The lavas range in composition from high-MgO, low-Al 2 O 3 (∼ 12 wt. % MgO, 14 wt. % Al 2 O 3 ) to high-Al 2 O 3 , low-MgO (∼ 18 wt. % Al 2 O 3 , 4 wt. % MgO). The high-MgO lavas are characterized by phenocrysts of olivine (cores FO 90–80 and rims FO 85–75 ) with chromite inclusions [Cr/(Cr + Al)≥0.7], clinopyroxene (Wo 46–42 En 48–42 Fs 15–7 ), and the rare occurrence of orthopyroxene (En 72–70 ). All the phenocrysts are normally zoned and set in a groundmass of plagioclase, pigeonite, clinopyroxene, magnetite, � orthopyroxene. The high-Al 2 O 3 basalts contain plagioclase (An 85–55 ), olivine (Fo 80–65 ), clinopyroxene (Wo 45–30 En 50–38 Fs 23–11 ), � orthopyroxene (En 72–70 ) phenocrysts, that preserve both normal and reverse zoning in a groundmass of plagioclase, pigeonite, olivine, clinopyroxene, magnetite, � orthopyroxene. Hybrid basalts have characteristics of both high-MgO basalts and high-Al 2 O 3 basalts and preserve complicated normal-to-reverse, reverse-to-normal, and normally zoned phenocrysts. No hydrous minerals are present in any of the lavas. The varied basaltic magmas erupted from Klyuchevskoy are derived from a magma chamber(s) located near the base of the Kamchatka crust (pressures ∼ 0.5–0.9 GPa) and characterized by relatively high crystallization temperatures, some in excess of ∼1150�C. Under these conditions, the fractionation of a parental ... |
format |
Text |
author |
KERSTING, ANNIE B. ARCULUS, RICHARD J. |
author_facet |
KERSTING, ANNIE B. ARCULUS, RICHARD J. |
author_sort |
KERSTING, ANNIE B. |
title |
Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt |
title_short |
Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt |
title_full |
Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt |
title_fullStr |
Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt |
title_full_unstemmed |
Klyuchevskoy Volcano, Kamchatka, Russia: The Role of High-Flux Recharged, Tapped, and Fractionated Magma Chamber(s) in the Genesis of High-Al2O3 from High-MgO Basalt |
title_sort |
klyuchevskoy volcano, kamchatka, russia: the role of high-flux recharged, tapped, and fractionated magma chamber(s) in the genesis of high-al2o3 from high-mgo basalt |
publisher |
Oxford University Press |
publishDate |
1994 |
url |
http://petrology.oxfordjournals.org/cgi/content/short/35/1/1 https://doi.org/10.1093/petrology/35.1.1 |
genre |
Kamchatka |
genre_facet |
Kamchatka |
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http://petrology.oxfordjournals.org/cgi/content/short/35/1/1 http://dx.doi.org/10.1093/petrology/35.1.1 |
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Copyright (C) 1994, Oxford University Press |
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https://doi.org/10.1093/petrology/35.1.1 |
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Journal of Petrology |
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35 |
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1 |
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1 |
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41 |
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1766051382851272704 |