 | Borisova, Anastassia Yu., Pichavant, Michel, Polvé, Mireille, Wiedenbeck, Michael, Freydier, Remi, Candaudap, Frédéric (2006) Trace element geochemistry of the 1991 Mt. Pinatubo silicic melts, Philippines: Implications for ore-forming potential of adakitic magmatism. Geochimica et Cosmochimica Acta, 70 (14) 3702-3716 doi:10.1016/j.gca.2006.04.030 | Journal (article/letter/editorial) | | element geochemistry of the 1991 Mt. Pinatubo silicic melts, Philippines: Implications for ore-forming potential...2006 Abstract The dacite pumice erupted from Mt. Pinatubo on June 15, 1991 (whole-rock, rhyolitic groundmass...minimum of 100 t Au and 5 · 105 t Cu from the Mt. Pinatubo magma. Our data suggest that intrusives having...Cl, Sr/Y, Pb/Ce, Mo/Ce, As/Ce and Sb/Ce in Mt. Pinatubo melts reflect the contribution of deep fluids derived...et al., Trace element geochemistry of the Mt. Pinatubo silicic melts 1997; Mungall, 2002). Understanding |  | | Journal (article/letter/editorial) | | 381–411 1999 The 15 June 1991 Eruption of Mount Pinatubo. I. Phase Equilibria and Pre-eruption P–T–f...ejected during the 15 June 1991 eruption of Mt Pinatubo, to define the pre-eruption conditions of this...abundances and the compositions of hornblende, plagioclase, and melt indicate that the eruption tapped a...greater than NNO + 1·5. Compositional zoning of plagioclase reflects crystallization over 150°C (900–750°C)...e-mail: bscaille@cnrs-orleans.fr contents of the plagioclase. Compositional zoning of hornblende is consistent |  | RodrÍguez, Carolina, Sellés, Daniel, Dungan, Michael, Langmuir, Charles, Leeman, William (2007) Adakitic Dacites Formed by Intracrustal Crystal Fractionation of Water-rich Parent Magmas at Nevado de Longaví Volcano (36·2°S; Andean Southern Volcanic Zone, Central Chile) Journal of Petrology, 48 (11) 2033-2061 doi:10.1093/petrology/egm049 | Journal (article/letter/editorial) | | Volcano (3628S; Andean SouthernVolcanic Zone, Central Chile) UNIVERSITE¤ DE GENE'VE, DE¤PARTEMENT DE...chemically distinct from other evolved magmas of the region in that they have high La/Yb (15^20) and Sr/Y (60^90)...plate margins originates in the high-temperature region of the asthenospheric mantle wedge as a consequence...hornblende and to significantly suppress residual plagioclase. Crystal fractionation of the requisite mineral...position of the SVZ relative to the Northern, Central, and Austral Volcanic zones (NVZ, CVZ, and AVZ |  | | Journal (article/letter/editorial) | | active arcs (Avacha of Kamchatka arc and Iraya of Luzon–Taiwan arc) to fertile spinel lherzolite of highpressure...replacement by the continental lherzolite at the region of backarc to continental margin. Asthenospheric...Asthenospheric upwelling beneath the continental region, which has frequently occurred at the Western Pacific, has...Continental margin 1. Introduction The Western Pacific region has been one of the most mobile zones, having had...Takahashi, 1978a; Aoki, 1987). The Western Pacific region is especially noteworthy to provide peridotite |  | Cao, Mingjian, Evans, Noreen J., Reddy, Steven M., Fougerouse, Denis, Hollings, Pete, Saxey, David W., McInnes, Brent I.A., Cooke, David R., McDonald, Bradley J., Qin, Kezhang (2019) Micro- and nano-scale textural and compositional zonation in plagioclase at the Black Mountain porphyry Cu deposit: Implications for magmatic processes. American Mineralogist, 104 (3) 391-402 doi:10.2138/am-2019-6609 | Journal (article/letter/editorial) | | nano-scale textural and compositional zonation in plagioclase at the Black Mountain porphyry Cu deposit: Implications...(10–100 mm) and nanoscale (10–100 nm) zoning in a plagioclase phenocryst from a fresh, syn-mineralization diorite...porphyry (Black Mountain porphyry Cu-Au deposit, Philippines) was characterized for major and trace elements...spectrometry, and atom probe tomography. The complex plagioclase crystal (3.0 × 5.4 mm) has a patchy andesine...crystallization. The occurrence of micro-scale zoning in plagioclase indicates a minimum cooling rate of 0.0005 °C/yr |  | | Journal (article/letter/editorial) | | progressive evolution by fractionation/assimilation in a central chamber is ambiguous. Rather than defining a liquid...concept of protracted in situ fractionation in a central subvolcanic magma chamber is an oversimplification...velocities (m/s) for grains of 1-mm radius of plagioclase (horizontal ticks) and magnetite (vertical ticks)...an ignimbrite sheet with a single-magma base, a central zone with two magma types, and a single-magma top...required by the considerable thickness of the central layer in which pumices of both magmas are present |  | | Journal (article/letter/editorial) | | of the dacite that chamber ascended through the central part of the conduit that suffered low shear stress...breakage of phenocrysts during magma ascent along the region of high shear stress near the conduit walls. The...deposits: the 1991 eruption products of Pinatubo, Philippines (Pallister et al., 1996; Polacci et al.... 2005; Rosi et al., 2004). Both eruptions, at Pinatubo and Quilotoa, are characterized by crystal rich...orthopyroxene and Fe Ti oxide analyses. For plagioclase and amphibole, a defocused (5 8 μm in diameter) |  | | Journal (article/letter/editorial) | | magma as hot as 1,030 C. Zoning profiles in plagioclase and/or magnetite phenocrysts indicate that mixing...estimated at 93–185 days based on the thickness of plagioclase overgrowth rims. Introduction Many studies have...solid dots (18, 77, CBV) Active volcanism in the region results from northward subduction of the Cocos...rhyodacitic glass (Fig. 2a) and <1 vol% phenocrysts of plagioclase, orthopyroxene, magnetite, and ilmenite, suggesting...but are regularly found attached to relatively calcic plagioclases (Fig. 2b), and are believed to be |  | | Journal (article/letter/editorial) | | 1993) ABSTRACT Lascar Volcano, located in the Central Volcanic Zone of Northern Chile, is a medium- to...Northern Volcanic Zone (NVZ) from 2°N to 5°S, the Central Volcanic Zone (CVZ) from 16°S to 28°S, and the...Zones the crust is 50 km thick or less, but the Central Zone is built on thick (50-70 km) crust. On the...B: Glaciation. Eruption of Aguas Calient** A: Central om http://petrology.oxfordjournals.org/ at Imperial...phenocryst phase in the eruption products is plagioclase. Large amounts of orthopyroxene and augite also |  | Ayati, Farimah, Yavuz, Fuat, Asadi, Hooshang H., Richards, Jeremy P., Jourdan, Fred (2013) Petrology and geochemistry of calc-alkaline volcanic and subvolcanic rocks, Dalli porphyry copper–gold deposit, Markazi Province, Iran. International Geology Review, 55 (2) 158-184 doi:10.1080/00206814.2012.689640 | Journal (article/letter/editorial) | | fractionation of amphibole and the suppression of plagioclase crystallization from hydrous calc-alkaline magmas...temperature–corrected Al-in-hornblende barometry and amphibole-plagioclase thermometry, suggest that the hornblende phenocrysts...3.8 ± 0.4 kbar. An alternative method using the calcic amphibole thermobarometer indicates that the Dalli...kbar. Keywords: porphyry Cu–Au deposit; Dalli; Central Iran; Miocene; diorite; granodiorite; hornblende;... These rocks contain phenocrysts of quartz, plagioclase, biotite, hornblende, and rarely pyroxene. The |  | | Journal (article/letter/editorial) | | conspicuous portion of the plagioclase phenocrysts in the Karymsky andesite has calcic cores, with compositions...of pre-existing chamber magma from the Karymsky central vent; (2) direct mixing of basaltic and andesitic...composition to ‘normal’, formed rims on inherited calcic plagioclase, and caused the resorption of dispersed olivine...Kamchatka; magma mixing; andesite; volcanic glass; plagioclase KEY WORDS: INTRODUCTION Downloaded from http://petrology...adjacent Academy Nauk caldera are located in the central part of the Eastern Volcanic Front of Kamchatka |  | | Report (chapter) | | monitoring record. These examples are drawn largely from Mount St. Helens volcano, for which there are abundant...variables (Fig. 1). Our generic volcano comprises a region of principal magma storage, typically referred...chamber to the surface above and to the magma source region below. Intensive parameters can vary spatially...inputs 3 Feeder system Crystal rich magma Source region Figure 1. Schematic of a sub-volcanic magma system...recharged via a feeder system from a deeper source region and discharged via a shallow conduit system connected |  | BROWNE, BRANDON L., EICHELBERGER, JOHN C., PATINO, LINA C., VOGEL, THOMAS A., DEHN, JONATHAN, UTO, KOZO, HOSHIZUMI, HIDEO (2006) Generation of Porphyritic and Equigranular Mafic Enclaves During Magma Recharge Events at Unzen Volcano, Japan. Journal of Petrology, 47 (2) 301-328 doi:10.1093/petrology/egi076 | Journal (article/letter/editorial) | | and porphyritic, and contain large, resorbed, plagioclase phenocrysts in a matrix of acicular crystals...Unzen Scientific Drilling Project; resorbed plagioclase INTRODUCTION Downloaded from http://petrology...% SiO2), with abundant large hornblende and plagioclase phenocrysts, and minor orthopyroxene, clinopyroxene...enclaves is characterized by abundant large plagioclase phenocrysts (Fig. 4) that exist in a groundmass...elongate, acicular microphenocrysts of mostly plagioclase and hornblende crystals and interstitial glass |  | | Journal (article/letter/editorial) | | Ascent-driven crystallisation of dacite magmas at Mount St Helens, 1980±1986 Received: 30 July 1999 / Accepted:...glasses in dacites from the 1980±1986 eruption of Mount St Helens volcano (WA) span a wide range in SiO2...The compositions of more evolved (higher SiO2) plagioclase-hosted inclusions and groundmass glasses are...ascent-driven fractional crystallisation of plagioclase, oxide and orthopyroxene phenocrysts and microlites...pressures. During this polybaric crystallisation, plagioclase phenocrysts trapped melts with a wide range of |  | | Report (chapter) | | Society, London, Memoirs Chapter 19 Magma storage region processes of the Soufrière Hills Volcano, Montserrat...Library on June 23, 2014 Chapter 19 Magma storage region processes of the Soufrière Hills Volcano, Montserrat...indicate that magma in the pre-existing magma storage region had been heated from approximately 825 to 835 8C...Potentially, global heating of magma in the storage region may influence magma rheology and eruptive styles...included approximately 45– 55 wt% phenocrysts of plagioclase, ferrohastingsitic amphibole, orthopyroxene, |  | | Journal (article/letter/editorial) | | mechanisms, and ‘Plagioclase exchange’ that is influenced by co-crystallizing plagioclase composition. The...supported by equilibrium calculations involving plagioclase and melt, and indicate some amphiboles are relicts...hotter thermal regime than that of the dominant plagioclase population and melt. Fast equilibrating melts...along with other equilibrium tools involving plagioclase and melts. Coupled with new temperature-oxygen...continental Australian plate. The geology of the region is extensively reviewed elsewhere (Wilson et al |  | | Journal (article/letter/editorial) | | saturated with five to eight mineral phases (plagioclase ? orthopyroxene ? titanomagnetite ? ilmenite...hornblende ± clinopyroxene ± sanidine ± pyrrhotite). Plagioclase and orthopyroxene phenocrysts (identified using...the Ni–NiO buffer. With temperature known, the plagioclase-liquid hygrometer was applied; maximum water...water concentrations calculated for the most calcic plagioclase phenocryst in each sample range from 2.6 to...proposed that the wide compositional range in plagioclase and orthopyroxene phenocrysts, despite their |  | | Journal (article/letter/editorial) | | Keywords: Hekla phase equilibria magma storage plagioclase zoning deformation a b s t r a c t Understanding...FeO and anorthite (CaAl2 Si2 O8 ) content in plagioclase reveal that thermal gradients were more important...(∼70 km) deformation of Uturuncu volcano in the Central Andes is probably caused by intrusion of intermediate...further interrogate chemical zoning profiles in plagioclase phenocrysts to investigate thermal and compositional...conducted to estimate the depth of the magma storage region beneath the volcano. Early studies, including repeated |  | | Report (chapter) | | long-lived historical eruptions have taken place in the region: Wadge et al. From: Wadge, G., Robertson, R. E...invoked for the dacite erupted in June 1991 at Pinatubo (Scaillet & Evans 1999). Melt inclusion studies...been proposed that prior to the 1991 eruption of Pinatubo, oxidized mafic magmas intruded the dacite reservoir...2009a). The phenocryst assemblage is 30– 35 vol% plagioclase feldspar, 6–10 vol% hornblende, 2– 5% orthopyroxene...are generally phenocryst-poor (,5 vol%), with plagioclase feldspar being the dominant framework phase, |  | | Journal (article/letter/editorial) | | these magmas have comparable phase assemblages (plagioclase ? orthopyroxene ? titanomagnetite ? ilmenite...relative to the Ni–NiO buffer. Application of the plagioclase-liquid hygrometer to each sample at these calculated...melt water concentrations of 4.6–3.1 wt% during plagioclase crystallization, indicating that the magmas were...wide, continuous range in the composition of plagioclase (B44 mol% An) and orthopyroxene (B16% Mg#) phenocrysts...concentrations favoring Fe-rich pyroxene. Both plagioclase and orthopyroxene commonly display diffusion-limited |  | | Journal (article/letter/editorial) | | chemical variation in plagioclase phenocrysts from the 1980 eruptions of Mount St. Helens, USA Kim Berlo...trace-element chemistry of plagioclase phenocrysts from the 1980 eruptions of Mount St. Helens volcano. Despite...considerable variation in textures and composition of plagioclase phenocrysts, distinct segments have been cross-correlated...compositionally different melts offset by the plagioclase crystallisation vector. In both of these melts...abundance of plagioclase in the 1980 dacites. We propose that rapid crystallisation of plagioclase upon magma |  | | Journal (article/letter/editorial) | | rhyolitic melts prior to degassing, and we use plagioclase–liquid hygrometry to calculate melt water contents...(2015). All samples are multiply saturated with plagioclase + orthopyroxene + titanomagnetite + ilmenite...ten samples as mineral inclusions in sparse plagioclase and orthopyroxene phenocrysts (e.g., Waters and...(MLV-36, -44, TEQ-21, PCR-R3, -7) are devoid of plagioclase microlites, which contains the time interval...suppression of groundmass crystallization of plagioclase, leading to a microlitefree obsidian, requires |  | | Book (edition) | | Our earliest ancestors evolved in the volcanic region of the East African Rift, where their activities...sport of nature that humans evolved in a volcanic region, or was this African volcanic environment especially...is, if the mantle rock were brought upward to a region of shallower depth in the Earth. It was only with...Krakatau, 1883 Mount Pelée, 1902 Paricutin, 1943 Bezymianny, 1956 Surtsey, 1963 Mount St. Helens, 1980...1980 El Chichon, 1982 Nevado del Ruiz, 1985 Pinatubo, 1991 B.C. One of the largest explosive eruptions |  | Czuppon, György, Lukács, Réka, Harangi, Szabolcs, Mason, Paul R.D., Ntaflos, Theodoros (2012) Mixing of crystal mushes and melts in the genesis of the Bogács Ignimbrite suite, northern Hungary: An integrated geochemical investigation of mineral phases and glasses. Lithos, 148. 71-85 doi:10.1016/j.lithos.2012.06.009 | Journal (article/letter/editorial) | | compositions. The mineral assemblage consists of plagioclase, orthopyroxene, biotite with minor and variable...from both basaltic and more silicic magmas. The calcic plagioclases (An = 80–90 mol%) and magnesian orthopyroxenes...Bükkalja volcanic field in northern Hungary (eastern-central Europe); provides an excellent place to investigate...silicic volcanic field in the Carpathian–Pannonian region (panel A) and the type-locality of the Bogács Ignimbrite...often with flattened tubular vesicles and contain plagioclase, quartz and biotite phenocrysts. The groundmass |  | Pallister, John S., Thornber, Carl R., Cashman, Katharine V., Clynne, Michael A., Lowers, Heather, Mandeville, Charles W., Brownfield, Isabelle K., Meeker, Gregory P. (2008) Petrology of the 2004-2006 Mount St. Helens lava dome -- implications for magmatic plumbing and eruption triggering. Professional Paper 1750_30. US Geological Survey doi:10.3133/pp175030 | Report (issue) | | A Volcano Rekindled: The Renewed Eruption of Mount St. Helens, 2004–2006 Edited by David R. Sherrod,...1750, 2008 Chapter 30 Petrology of the 2004–2006 Mount St. Helens Lava Dome—Implications for Magmatic Plumbing...eruptions ended in 1986, and with little warning, Mount St. Helens began to erupt again in October 2004...incompatible elements of the magmas erupted at Mount St. Helens during the past 500 years. Since shortly...80225 4 5 American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 samples |
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