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- W2030428138 abstract "Hydrogen isotope ratio, water content and Fe3 +/Fe2 + in coexisting amphibole and biotite phenocrysts in volcanic rocks can provide insight into shallow pre- and syn-eruptive magmatic processes such as vesiculation, and lava drainback with mixing into less devolatilized magma that erupts later in a volcanic sequence. We studied four ~ 35 ka and younger eruption sequences (i.e. Kings Creek, Lassen Peak, Chaos Crags, and 1915) at the Lassen Volcanic Center (LVC), California, where intrusion of crystal-rich silicic magma mushes by mafic magmas is inferred from the varying abundances of mafic magmatic inclusions (MMIs) in the silicic volcanic rocks. Types and relative proportions of reacted and unreacted hydrous phenocryst populations are evaluated with accompanying chemical and H isotope changes. Biotite phenocrysts were more susceptible to rehydration in older vesicular glassy volcanic rocks than coexisting amphibole phenocrysts. Biotite and magnesiohornblende phenocrysts toward the core of the Lassen Peak dome are extensively dehydroxylated and reacted from prolonged exposure to high temperature, low pressure, and higher fO2 conditions from post-emplacement cooling. In silicic volcanic rocks not affected by alteration, biotite phenocrysts are often relatively more dehydroxylated than are magnesiohornblende phenocrysts of similar size; this is likely due to the ca 10 times larger overall bulk H diffusion coefficient in biotite. A simplified model of dehydrogenation in hydrous phenocrysts above reaction closure temperature suggests that eruption and quench of magma ascended to the surface in a few hours is too short a time for substantial H loss from amphibole. In contrast, slowly ascended magma can have extremely dehydrogenated and possibly dehydrated biotite, relatively less dehydrogenated magnesiohornblende and reaction rims on both phases. Eruptive products containing the highest proportions of mottled dehydrogenated crystals could indicate that within a few days prior to eruption, degassed vesiculated magma or lava had drained back down the volcanic conduit and mixed with less devolatilized magma. The vesiculated magma contained hydrous phenocrysts with lattice damage, which locally raised the effective H diffusion coefficient by ca 10–100 × and resulted in increased mineral dehydrogenation. Remobilization of dacite magma mush by relatively more reduced mafic magma appears to have generated further fO2 variations in May 1915 as oxidized magma from shallow levels circulated to depths where dehydrogenation of hydrous phenocrysts began. The δDMagmatic H2O expressed in LVC acid hot springs is likely a mixture derived from devolatilized ascending mafic magmas and crystallizing silicic magma mush." @default.
- W2030428138 created "2016-06-24" @default.
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- W2030428138 date "2012-05-01" @default.
- W2030428138 modified "2023-09-27" @default.
- W2030428138 title "Hydrogen isotope investigation of amphibole and biotite phenocrysts in silicic magmas erupted at Lassen Volcanic Center, California" @default.
- W2030428138 cites W101982721 @default.
- W2030428138 cites W1207354341 @default.
- W2030428138 cites W1523852427 @default.
- W2030428138 cites W1971267582 @default.
- W2030428138 cites W1981524330 @default.
- W2030428138 cites W1995106978 @default.
- W2030428138 cites W1996361224 @default.
- W2030428138 cites W2000126527 @default.
- W2030428138 cites W2001653617 @default.
- W2030428138 cites W2001743379 @default.
- W2030428138 cites W2002132035 @default.
- W2030428138 cites W2002525407 @default.
- W2030428138 cites W2005637065 @default.
- W2030428138 cites W2006139581 @default.
- W2030428138 cites W2006434547 @default.
- W2030428138 cites W2007684610 @default.
- W2030428138 cites W2008099803 @default.
- W2030428138 cites W2012411784 @default.
- W2030428138 cites W2016875897 @default.
- W2030428138 cites W2024418086 @default.
- W2030428138 cites W2024572491 @default.
- W2030428138 cites W2025307763 @default.
- W2030428138 cites W2026227982 @default.
- W2030428138 cites W2026930688 @default.
- W2030428138 cites W2032271031 @default.
- W2030428138 cites W2034526979 @default.
- W2030428138 cites W2035534401 @default.
- W2030428138 cites W2045642416 @default.
- W2030428138 cites W2045764565 @default.
- W2030428138 cites W2049120266 @default.
- W2030428138 cites W2050622444 @default.
- W2030428138 cites W2052586810 @default.
- W2030428138 cites W2055595543 @default.
- W2030428138 cites W2061162406 @default.
- W2030428138 cites W2069243531 @default.
- W2030428138 cites W2070020726 @default.
- W2030428138 cites W2071362208 @default.
- W2030428138 cites W2074636974 @default.
- W2030428138 cites W2079371725 @default.
- W2030428138 cites W2081830829 @default.
- W2030428138 cites W2084995136 @default.
- W2030428138 cites W2085849006 @default.
- W2030428138 cites W2086190141 @default.
- W2030428138 cites W2090107047 @default.
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- W2030428138 cites W2101110196 @default.
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- W2030428138 cites W2167568423 @default.
- W2030428138 cites W2327885894 @default.
- W2030428138 cites W2338617351 @default.
- W2030428138 cites W342937969 @default.
- W2030428138 doi "https://doi.org/10.1016/j.jvolgeores.2012.02.019" @default.
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