DOCSLIB.ORG

Geochemistry of the Alkaline Volcanic

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Geochemistry of the Alkaline Volcanic DOI: 10.1590/23174889201500020009 INVITED REVIEW Geochemistry of the alkaline volcanic- subvolcanic rocks of the Fernando de Noronha Archipelago, southern Atlantic Ocean Geoquímica das rochas vulcânicas-subvulcânicas alcalinas do Arquipélago de Fernando de Noronha, Oceano Atlântico Meridional Rosana Peporine Lopes1, Mabel Norma Costas Ulbrich2* ABSTRACT: The Fernando de Noronha Archipelago presents, on RESUMO: O Arquipélago de Fernando de Noronha mostra na sua its main island, a centrally-located stratigraphic unit, the Remédios ilha principal, na parte central, a Formação Remédios (idade em torno Formation (age around 8 – 12 Ma) constituted by basal pyroclastic de 8 – 12 Ma) constituída por rochas piroclásticas basais invadidas por rocks intruded by dikes, plugs and domes of varied igneous rocks, diques, plugs e domos de variadas rochas ígneas, capeadas por derrames capped by flows and pyroclastics of mafic to ultramafic rocks of e piroclásticas das rochas máficas a ultramáficas da Formação Quixaba the Quixaba Formation (age around 1 – 3 Ma), which is limited (idade de 1 a 3 Ma), separada da unidade inferior por uma superfície de from the underlying unit by an extensive irregular erosion surface. erosão extensa e irregular. Uma série predominante sódica de Remédios A predominant sodic Remédios series (basanites, tephrites, tephri- (basanitos, tefritos, tefrifonolitos, essexito, fonolitos) pode ser diferencia- phonolites, essexite, phonolites) can be separated from a moderately da da série moderadamente potássica (álcali basaltos, traquiandesitos, potassic Remédios sequence (alkali basalts, trachyandesites, tra- traquitos), pertencente à mesma unidade. Ambas as séries mostram ten- chytes), both alkaline series showing mostly continuous geochemi- dências geoquímicas geralmente contínuas em diagramas de variação de cal trends in variation diagrams for major as well as trace elements, elementos maiores e traços, indicando origem por cristalização fracionada indicating evolution by crystal fractionation (mainly, separation of (principalmente, separação de minerais máficos, incluindo apatitas e ti- mafic minerals, including apatites and titanites). There are textur- tanitas). São encontradas evidências mineralógicas e texturais apontando al and mineralogical evidences pointing to hybrid origin of some para origens hibridas em algumas rochas intermediárias (e.g., fenocristais intermediate rocks (e.g., resorbed pyroxene phenocrysts in basaltic reabsorbidos de piroxênio em traquiandesitos basálticos e alguns lampró- trachyandesites, and in some lamprophyres). The primitive Quixaba firos). As rochas primitivas do evento Quixaba, também alcalinas, são rocks are mostly melanephelinites and basanites, primitive under- mormente melanefelinitos fortemente insaturados e basanitos. A geologia saturated sodic types. Geology (erosion surface), stratigraphy (two (superfície de erosão), estratigrafia (dois eventos magmáticos distintos se- distinct units separated by a large time interval), petrography (varied parados por período prolongado), petrografia (evento Remédios petrogra- Remédios Formation, more uniform Quixaba unit) and geochemis- ficamente variado, o Quixaba mais uniforme) e geoquímica indicam try indicate that the islands represent the activity of a protracted vol- que as ilhas são o resultado de prolongado vulcanismo, alimentado por canic episode, fueled by intermittent melting of an enriched mantle, fundidos intermitentes de manto enriquecido, não relacionado com ati- not related to asthenospheric plume activity. vidade de pluma astenoférica. KEYWORDS: OIB; South Atlantic Ocean; Mafic to ultramafic PALAVRAS-CHAVES: OIB; Oceâno Atlántico meridional; rochas volcanic-subvolcanic rocks; Sodic and potassic series. vulcânicas-subvulcânicas máficas a ultramáficas; séries sódica e potássica. 1Pós-graduação, Instituto de Geociências, Universidade de São Paulo – USP, São Paulo (SP), Brazil. E-mail: [email protected] 2Instituto de Geociências,Universidade de São Paulo – USP, São Paulo(SP), Brazil. E-mail: [email protected] *Corresponding author Manuscript ID: 30305. Received: 04/12/2015. Approved: 05/18/2015. 307 Brazilian Journal of Geology, 45(2): 307-333, June 2015 Geochemistry of volcanic rocks of Fernando de Noronha INTRODUCTION Quixaba Formation. Almeida also separated the basanitic rocks outcropping at the São José peninsula, containing Within-plate oceanic islands are made up mostly o fa mantle xenoliths, from the Quixaba rocks and defined them series of diverse alkaline volcanic and subvolcanic rocks of as the youngest São José Formation. a basaltic ancestry, collectively called oceanic island basalts The next contribution to the FN geology was provided (OIB), clearly separated from the occurrences related to by Cordani (1970), who published K-Ar geochronological midoceanic ridge basalts (MORB), which belong to the data for the various rock types (K-Ar methodology; cf. also tholeiitic series. The name OIB, however, covers a wide Cordani et al. 2004). More recent and more precise 40Ar/39Ar range of petrographic and chemical variations, as displayed results can be found in Perlingeiro et al. (2013). in the literature on these rocks. The archipelago was visited sporadically by geologists Specifically in the Atlantic Ocean, many OIB islands who added geochemical and isotopic data (Gunn & Watkins are known and have been extensively studied, such as the 1976; Stormer & Whitney 1978; Schwab & Bloch 1985; Canarias Islands (Hoernle & Schmincke 1993; Araña et al. Cornen 1986; Gerlach et al. 1987; Weaver 1990). 1994; Gurenko et al. 2006), the Cabo Verde Archipelago More recently, geologists from the University of São (Furnes & Stillman 1987; Dyhr & Holm 2010; Ancochea Paulo presented contributions on FN (two Master’s thesis, et al. 2012) and the islands of Trindade and Martin Vaz one doctorate thesis: Maríngolo 1995; Lopes 1997, 2002), (Almeida 1961; Marques et al. 1999; Siebel et al. 2000). and several abstracts and publications on the subject (Ulbrich The Fernando de Noronha (FN) Archipelago is situated & Ruberti 1992; Ulbrich 1993; Ulbrich et al. 1994, 2004; in the southern Atlantic Ocean, at longitudes 32o 28’ to Maríngolo & Ulbrich 1997; Lopes & Ulbrich 1997, 1998; 32o 24’W and parallels 3o 52’ to 3o 50’ south. It outcrops at Ulbrich & Lopes 2000a, 2000b).A summary paper on the about 345 km from the nearest coastline (the Brazilian state lithogeochemistry and mineral chemistry of the Quixaba of Rio Grande do Norte), and belongs administratively to Formation was published in a Brazilian journal (Lopes & the state of Pernambuco, Brazil. It covers 18.4 km2, consti- Ulbrich 2006), and a more recent one on the mineral chem- tuted by one large island (16.9 km2), with a main NE-SW istry of these rocks (Lopes et al. 2014). A recent study on FN trending course, and many smaller islands (along both the was presented at Queensland as a Ph.D. thesis, dealing with occidental outlines of the main island, as well as a string geochronologic and petrogenetic aspects (Perlingeiro 2012). of them extending to the NE: Cuscuz, São José, Rasa, Sela Field work consisted mainly in the recognition and sam- Gineta, do Meio, Rata). pling of the several rock types identified by Almeida, add- The archipelago belongs to a vast volcanic edifice posi- ing more detailed information on the presence of dikes and tioned along the Fernando de Noronha ridge that rests on their structural disposition. The whole district is now mostly the ocean floor at a depth of around 4,000 m, stretching a natural reserve (Parque Nacional Marinho or Parnamar, some 75 km along an E-W trending fracture zone (Almeida the National Marine Park), subjected to oversight by the 1955, 2012; Bryan et al. 1972), which is supposed to have Brazilian Environmental Agency (Instituto Brasileiro de Meio channeled to the surface mantle-derived magmas. The old- Ambiente – IBAMA). IBAMA granted permission for col- est registered volcanism along this fracture zone is found lecting samples even in areas of total protection under their on its alleged continuation on the continental margin, jurisdiction. A total of about 109 hand specimens were col- at Ceará state, there presenting locally alkaline magma- lected in several field trips (1989, 1997, 1999). tism, dated 40 Ma ago, interpreted by some authors to be the result of the activity of a plume (appropriately called the Fernando de Noronha plume) impacting the westward STRATIGRAPHIC UNITS moving Southamerican plate. This plume is supposedly AND GEOLOGIC OCCURRENCES also the heat source responsible for the eruption of the Fernando de Noronha volcanic rocks (Fodor et al. 1998, Almeida (1955) mapped two units in the Archipelago, 2002; Almeida 2012). the older Remédios Formation, exposed as a centrally located The geologic units in FN were mapped by Fernando de erosion window, constituted mainly by accumulations of pyro- Almeida, who presented a classic publication on the geol- clastic material intruded by several dike systems and various ogy, petrography, stratigraphy and geomorphology of the plugs and domes, and the subhorizontal flows of the younger islands (Almeida 1955; see Fig. 1). Almeida defined two Quixaba Formation, bordering the Remédios Formation on main mapping units, the products of two volcanic events, both sides (to the NE and to the SW; Fig. 1). The pyroclas- the older Remédios Formation, separated by an erosion tic beds in the Remédios Formation are deeply altered and surface from the overlying, petrographically more uniform converted to soil
Load more

Recommended publications
  • Comments On'kaersutite from San Carlos, Arizona, with Comments On
    MINERALOGICAL MAGAZINE, SEPTEMBER I969, VOL. 37, NO. 287 Comments on 'Kaersutite from San Carlos, Arizona, with comments on the paragenesis of this mineral' by Brian Mason MARTIN PRINZ ~ Department of Geology, University of New Mexico, Albuquerque, New Mexico 87Io6 AND C. E. NEHRU Department of Geology, Brooklyn College, Brooklyn, New York II2~O s u MM A R Y. Electron probe analyses have been made of eight kaersutites from San Carlos, A~cizona, and one from Kakanui, New Zealand; also of olivine, clinopyroxene, ilmenite, and spinel from San Carlos. There is not as yet adequate evidence that the kaersutite is an upper mantle phase. MASON (I968a) suggests that kaersutite, as exemplified by the occurrence at San Carlos, Arizona, as well as from some other localities, may represent the amphibole phase in upper mantle rocks. The possibility of amphibole as an upper mantle phase was most clearly suggested by Oxburgh (I964) since it would help explain the alkali content of basaltic rocks, which otherwise would be derived from alkali-poor ultra- mafic mantle rocks. Since we are carrying out a detailed study of the ultramafic inclusions of the San Carlos, Arizona, locality, we would like to clarify some of the petrologic significance of the kaersutite from this area because it leads us to different conclusions from those of Mason. Hopefully, our comments will be of value to others suggesting amphibole as an upper mantle phase. San Carlos locality. The kaersutite described by Mason (I968a) in the San Carlos locality occurs as a granular aggregate of anhedral crystals, with a little inter-granular ilmenite.
    [Show full text]
  • Geology of the Nairobi Region, Kenya
    % % % % % % % % %% %% %% %% %% %% %% % GEOLOGIC HISTORY % %% %% % % Legend %% %% %% %% %% %% %% % % % % % % HOLOCENE: %% % Pl-mv Pka %%% Sediments Mt Margaret U. Kerichwa Tuffs % % % % %% %% % Longonot (0.2 - 400 ka): trachyte stratovolcano and associated deposits. Materials exposed in this map % %% %% %% %% %% %% % section are comprised of the Longonot Ash Member (3.3 ka) and Lower Trachyte (5.6-3.3 ka). The % Pka' % % % % % % L. Kerichwa Tuff % % % % % % Alluvial fan Pleistocene: Calabrian % % % % % % % Geo% lo% gy of the Nairobi Region, Kenya % trachyte lavas were related to cone building, and the airfall tuffs were produced by summit crater formation % % % % % % % % % % % % % % % % % Pna % % % % %% % (Clarke et al. 1990). % % % % % % Pl-tb % % Narok Agglomerate % % % % % Kedong Lake Sediments Tepesi Basalt % % % % % % % % % % % % % % % % %% % % % 37.0 °E % % % % 36.5 °E % % % % For area to North see: Geology of the Kijabe Area, KGS Report 67 %% % % % Pnt %% % PLEISTOCENE: % % %% % % % Pl-kl %% % % Nairobi Trachyte % %% % -1.0 ° % % % % -1.0 ° Lacustrine Sediments % % % % % % % % Pleistocene: Gelasian % % % % % Kedong Valley Tuff (20-40 ka): trachytic ignimbrites and associated fall deposits created by caldera % 0 % 1800 % % ? % % % 0 0 % % % 0 % % % % % 0 % 0 8 % % % % % 4 % 4 Pkt % formation at Longonot. There are at least 5 ignimbrite units, each with a red-brown weathered top. In 1 % % % % 2 % 2 % % Kiambu Trachyte % Pl-lv % % % % % % % % % % %% % % Limuru Pantellerite % % % % some regions the pyroclastic glass and pumice has been
    [Show full text]
  • Source to Surface Model of Monogenetic Volcanism: a Critical Review
    Downloaded from http://sp.lyellcollection.org/ by guest on September 28, 2021 Source to surface model of monogenetic volcanism: a critical review I. E. M. SMITH1 &K.NE´ METH2* 1School of Environment, University of Auckland, Auckland, New Zealand 2Volcanic Risk Solutions, Massey University, Palmerston North 4442, New Zealand *Correspondence: [email protected] Abstract: Small-scale volcanic systems are the most widespread type of volcanism on Earth and occur in all of the main tectonic settings. Most commonly, these systems erupt basaltic magmas within a wide compositional range from strongly silica undersaturated to saturated and oversatu- rated; less commonly, the spectrum includes more siliceous compositions. Small-scale volcanic systems are commonly monogenetic in the sense that they are represented at the Earth’s surface by fields of small volcanoes, each the product of a temporally restricted eruption of a composition- ally distinct batch of magma, and this is in contrast to polygenetic systems characterized by rela- tively large edifices built by multiple eruptions over longer periods of time involving magmas with diverse origins. Eruption styles of small-scale volcanoes range from pyroclastic to effusive, and are strongly controlled by the relative influence of the characteristics of the magmatic system and the surface environment. Gold Open Access: This article is published under the terms of the CC-BY 3.0 license. Small-scale basaltic magmatic systems characteris- hazards associated with eruptions, and this is tically occur at the Earth’s surface as fields of small particularly true where volcanic fields are in close monogenetic volcanoes. These volcanoes are the proximity to population centres.
    [Show full text]
  • Siluro-Devonian Igneous Rocks of the Easternmost Three Terranes in Southeastern New England: Examples from Ne Massachusetts and Se New Hampshire
    SILURO-DEVONIAN IGNEOUS ROCKS OF THE EASTERNMOST THREE TERRANES IN SOUTHEASTERN NEW ENGLAND: EXAMPLES FROM NE MASSACHUSETTS AND SE NEW HAMPSHIRE by Rudolph Hon, Department of Geology and Geophysics, Boston College, Chestnut Hill, MA 02467 J. Christopher Hepburn, Dept. of Geology and Geophysics, Boston College, Chestnut Hill, MA 02467 Jo Laird, Dept. of Earth Sciences, University of New Hampshire, Durham, NH 03824 INTRODUCTION Siluro-Devonian igneous rocks in northeastern Massachusetts and adjacent southern New Hampshire have been the subject of mineralogical, petrological and geological studies for over 150 years (Rodgers et al., 1989; Brady and Cheney, 2004), but only in recent times has it been recognized that these rocks lie in three distinct geological terranes. These rocks include a diverse variety of plutonic and volcanic rocks ranging in chemistry from peralkaline to calc-alkaline. Of particular note are the widely known mid-Paleozoic alkaline plutons that include the type localities of both the rock “essexite,” nepheline monzogabbro to nepheline monzodiorite (Sears, 1891), and the mineral “annite,” iron biotite (Dana, 1868). This field excursion is designed to demonstrate the diversity of the igneous rocks in the area and to visit (weather permitting) some of the classic localities. Throughout the excursion, the relationship of the timing and petrogenesis of the magmatism to the tectonics will be considered. It is impossible to exhaustibly discuss or credit all the work that has led to our current understanding of the igneous rocks in this region. The list includes many petrologists such as H.S. Washington, N. S. Shaler, C. H. Clapp, N. L. Bowen, J.
    [Show full text]
  • Kaersutite-Bearing Xenoliths and Megacrysts in Volcanic Rocks from the Funk Seamount in the Southwest Indian Ocean
    Kaersutite-bearing xenoliths and megacrysts in volcanic rocks from the Funk Seamount in the southwest Indian Ocean ARCH M. REID* AND ANTON P. LE ROEX Department of Geology, University of Cape Town, Rondebosch 7700, South Africa Abstract Eight samples (seven volcanic rocks and one quartz sandstone) have been dredged from the Funk Seamount, 60 km NW of Marion Island in the southwest Indian Ocean Oat. 46 ~ 15' S, long. 37 ~ 20' E). The volcanic rocks are fine-grained vesicular basanitoids and glass-rich volcanic breccias geochemically similar to the Marion Island lavas. Lavas and breccias contain a suite of megacryst minerals and of small polymineralic xenoliths, in both of which kaersutite is a prominent constituent. The megacryst suite comprises large unzoned single grains of kaersutite, plagioclase, pyroxene, magnetite and ilmenite, all showing textural evidence of resorption/reaction with the basanitoid host. The megacrysts have a limited range of compositions except for the plagioclase which ranges from oligoclase to labradorite. The small (2 mm to ~ 3 cm) xenoliths are mostly two-pyroxene amphibole assemblages with or without olivine, magnetite, ilmenite, plagioclase and apatite. The xenoliths show some evidence of reaction with the basanitoid host and most have undergone recrystallization and/or localised decompression melting. Xenolith and megacryst assemblages are interpreted as being associated with the formation and partial crystallization of a hydrous basanitoid melt at depth. KEYWORDS: kaersutite, amphibole, xenolith, Funk Seamount, Indian Ocean. Introduction megacrysts. Brown amphibole is a prominent con- stituent of both xenolith and megacryst suites. F U N K S E A M O U N T is a prominent seamount situa- Mantle xenoliths in abyssal lavas are rare and so ted 60 km to the NW of Marion and Prince Edward these samples are of particular interest.
    [Show full text]
  • Nonexplosive and Explosive Magma/Wet-Sediment Interaction
    Journal of Volcanology and Geothermal Research 181 (2009) 155–172 Contents lists available at ScienceDirect Journal of Volcanology and Geothermal Research journal homepage: www.elsevier.com/locate/jvolgeores Nonexplosive and explosive magma/wet-sediment interaction during emplacement of Eocene intrusions into Cretaceous to Eocene strata, Trans-Pecos igneous province, West Texas Kenneth S. Befus a,⁎, Richard E. Hanson a, Daniel P. Miggins b, John A. Breyer a, Arthur B. Busbey a a Department of Geology, Texas Christian University, Box 298830, Fort Worth, TX 76129, USA b U.S. Geological Survey, Denver Federal Center, Box 25046, Denver, CO 80225, USA article info abstract Article history: Eocene intrusion of alkaline basaltic to trachyandesitic magmas into unlithified, Upper Cretaceous Received 16 June 2008 (Maastrichtian) to Eocene fluvial strata in part of the Trans-Pecos igneous province in West Texas produced Accepted 22 December 2008 an array of features recording both nonexplosive and explosive magma/wet-sediment interaction. Intrusive Available online 13 January 2009 complexes with 40Ar/39Ar dates of ~47–46 Ma consist of coherent basalt, peperite, and disrupted sediment. Two of the complexes cutting Cretaceous strata contain masses of conglomerate derived from Eocene fluvial Keywords: deposits that, at the onset of intrusive activity, would have been N400–500 m above the present level of phreatomagmatism peperite exposure. These intrusive complexes are inferred to be remnants of diatremes that fed maar volcanoes during diatreme an early stage of magmatism in this part of the Trans-Pecos province. Disrupted Cretaceous strata along Trans-Pecos Texas diatreme margins record collapse of conduit walls during and after subsurface phreatomagmatic explosions.
    [Show full text]
  • Derivation of Intermediate to Silicic Magma from the Basalt Analyzed at the Vega 2 Landing Site, Venus
    RESEARCH ARTICLE Derivation of intermediate to silicic magma from the basalt analyzed at the Vega 2 landing site, Venus J. Gregory Shellnutt* National Taiwan Normal University, Department of Earth Sciences, Taipei, Taiwan * [email protected] Abstract a1111111111 a1111111111 Geochemical modeling using the basalt composition analyzed at the Vega 2 landing site a1111111111 indicates that intermediate to silicic liquids can be generated by fractional crystallization and a1111111111 equilibrium partial melting. Fractional crystallization modeling using variable pressures (0.01 a1111111111 GPa to 0.5 GPa) and relative oxidation states (FMQ 0 and FMQ -1) of either a wet (H2O = 0.5 wt%) or dry (H2O = 0 wt%) parental magma can yield silicic (SiO2 > 60 wt%) composi- tions that are similar to terrestrial ferroan rhyolite. Hydrous (H2O = 0.5 wt%) partial melting can yield intermediate (trachyandesite to andesite) to silicic (trachydacite) compositions at OPEN ACCESS all pressures but requires relatively high temperatures ( 950ÊC) to generate the initial melt Citation: Shellnutt JG (2018) Derivation of at intermediate to low pressure whereas at high pressure (0.5 GPa) the first melts will be intermediate to silicic magma from the basalt generated at much lower temperatures (< 800ÊC). Anhydrous partial melt modeling yielded analyzed at the Vega 2 landing site, Venus. PLoS mafic (basaltic andesite) and alkaline compositions (trachybasalt) but the temperature ONE 13(3): e0194155. https://doi.org/10.1371/ journal.pone.0194155 required to produce the first liquid is very high ( 1130ÊC). Consequently, anhydrous partial melting is an unlikely process to generate derivative liquids. The modeling results indicate Editor: Axel K Schmitt, Heidelberg University, GERMANY that, under certain conditions, the Vega 2 composition can generate silicic liquids that pro- duce granitic and rhyolitic rocks.
    [Show full text]
  • Geological Mapping, Structural Setting and Petrographic Description of the Archean Volcanic Rocks of Mnanka Area, North Mara
    PROCEEDINGS, 43rd Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, February 12-14, 2018 SGP-TR-213 Geological Mapping, Structural Setting and Petrographic Description of the Archean Volcanic Rocks of Mnanka Area, North Mara Ezra Kavana Acacia Mining PLc, North Mara Gold Mine, Department of Geology, P. O. Box 75864, Dar es Salaam, Tanzania Email: [email protected] Keywords: Musoma Mara Greenstone Belt, Mnanka volcanics, Archaean rocks and lithology ABSTRACT The Mnanka area is situated within the Musoma Mara Greenstone Belt, the area is near to Nyabigena, Gokona and Nyabirama gold mines. Mnanka area comprises of the sequence of predominant rhyolitic volcanic rocks, chert and metasediments. Gold mineralizations in Mnanka area is structure controlled and occur mainly as hydrothermal disseminated intrusion related deposits. Hence the predominant observed structures are joints and flow banding. Measurements from flow banding plotted on stereonets using win-TENSOR software has provided an estimate for the general strike of the area lying 070° to 100° dipping at an average range angle of 70° to 85° while data from joints plotted on stereonets suggest multiple deformation events one of which conforms to the East Africa Rift System (striking WSW-ENE, NNE-SSW and N-S). 1. INTRODUCTION This paper focuses on performing a systematic geological mapping and description of structures and rocks of the Mnanka area. The Mnanka area is located in the Mara region, Tarime district within the Musoma Mara Greenstone Belt. The gold at Mnanka is host ed by volcanic rocks that belong to the Musoma Mara Greenstone Belt (Figure 1). The Mnanka volcanics are found within the Kemambo group that comprises of the sequence of predominant rhyolitic volcanic rocks, chert and metasediments south of the Nyarwana fault.
    [Show full text]
  • Relationships Between Pre-Eruptive Conditions and Eruptive Styles of Phonolite-Trachyte Magmas Joan Andújar, Bruno Scaillet
    Relationships between pre-eruptive conditions and eruptive styles of phonolite-trachyte magmas Joan Andújar, Bruno Scaillet To cite this version: Joan Andújar, Bruno Scaillet. Relationships between pre-eruptive conditions and eruptive styles of phonolite-trachyte magmas. Lithos, Elsevier, 2012, 152 (1), pp.122-131. 10.1016/j.lithos.2012.05.009. insu-00705854 HAL Id: insu-00705854 https://hal-insu.archives-ouvertes.fr/insu-00705854 Submitted on 10 Jul 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Relationships between pre-eruptive conditions and eruptive styles of phonolite-trachyte magmas JOAN ANDÚJAR*,a AND BRUNO SCAILLETa a. CNRS/INSU-UNIVERSITÉ D’ORLÉANS-BRGM ; INSTITUT DES SCIENCES DE LA TERRE D’ORLEANS, UMR 6113 - 1A, RUE DE LA FÉRROLLERIE-45071 ORLEANS CEDEX 2 (FRANCE) * Corresponding author : Joan Andújar phone number : (+33) 2 38 25 53 87 Fax: (+33) 02 38 63 64 88 e-mail address: [email protected] Bruno Scaillet e-mail address: [email protected] KEY WORDS: Phase equilibria, phonolite, trachyte, experimental petrology, eruptive dynamic, explosive, effusive, andesite, rhyolite, melt viscosity, magma viscosity. 2 Abstract Phonolitic eruptions can erupt either effusively or explosively, and in some cases develop highly energetic events such as caldera-forming eruptions.
    [Show full text]
  • Stitial Oxide Ions Synthesized by Direct Crystallization
    La2Ga3O7.5: a metastable ternary melilite with a super-excess of inter- stitial oxide ions synthesized by direct crystallization of the melt Jintai Fan, Vincent Sarou-Kanian, Xiaoyan Yang, Maria Diaz-Lopez, Franck Fayon, Xiaojun Kuang, Michael Pitcher, Mathieu Allix To cite this version: Jintai Fan, Vincent Sarou-Kanian, Xiaoyan Yang, Maria Diaz-Lopez, Franck Fayon, et al.. La2Ga3O7.5: a metastable ternary melilite with a super-excess of inter- stitial oxide ions synthe- sized by direct crystallization of the melt. Chemistry of Materials, American Chemical Society, 2020, 32 (20), pp.9016-9025. 10.1021/acs.chemmater.0c03441. hal-02959774 HAL Id: hal-02959774 https://hal.archives-ouvertes.fr/hal-02959774 Submitted on 7 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. La2Ga3O7.5: a metastable ternary melilite with a super-excess of inter- stitial oxide ions synthesized by direct crystallization of the melt Jintai Fan,1,2 Vincent Sarou-Kanian,1 Xiaoyan Yang,3 Maria Diaz-Lopez,4,5 Franck Fayon,1 Xiaojun Kuang,3,6 Michael J. Pitcher1* and Mathieu Allix1* 1 CNRS, CEMHTI UPR3079, 45071 Orléans, France 2 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai, 201800, P.
    [Show full text]
  • Iron Isotope Compositions of Carbonatites Record Melt Generation, Crystallization, and Late-Stage Volatile-Transport Processes
    Miner Petrol (2010) 98:91–110 DOI 10.1007/s00710-009-0055-4 ORIGINAL PAPER Iron isotope compositions of carbonatites record melt generation, crystallization, and late-stage volatile-transport processes Clark M. Johnson & Keith Bell & Brian L. Beard & Aaron I. Shultis Received: 6 January 2009 /Accepted: 1 May 2009 /Published online: 30 May 2009 # Springer-Verlag 2009 Abstract Carbonatites define the largest range in Fe iso- fluid-rock or fluid-magma interactions comes from the tope compositions yet measured for igneous rocks, record- common occurrence of Fe isotope disequilibrium among ing significant isotopic fractionations between carbonate, carbonate, oxide, silicate, and sulfide minerals in the oxide, and silicate minerals during generation in the mantle majority of the carbonatites studied. The common occurrence and subsequent differentiation. In contrast to the relatively of Fe isotope disequilibrium among minerals in carbonatites restricted range in δ56Fe values for mantle-derived basaltic may also indicate mixing of phenocyrsts from distinct magmas (δ56Fe=0.0±0.1‰), calcite from carbonatites have magmas. Expulsion of Fe3+-rich brines into metasomatic δ56Fe values between −1.0 and +0.8‰, similar to the range aureols that surround carbonatite complexes are expected to defined by whole-rock samples of carbonatites. Based on produce high-δ56Fe fenites, but this has yet to be tested. expected carbonate-silicate fractionation factors at igneous or mantle temperatures, carbonatite magmas that have modestly negative δ56Fe values of ~ −0.3‰ or lower can Introduction be explained by equilibrium with a silicate mantle. More negative δ56Fe values were probably produced by differen- Stable and radiogenic isotope studies of carbonatites have tiation processes, including crystal fractionation and liquid been used to monitor the secular evolution of the sub- immiscibility.
    [Show full text]
  • The Alkaline Volcanic Rocks of Craters of the Moon National Monument, Idaho and the Columbia Hills of Gusev Crater, Mars Details
    The alkaline volcanic rocks of Craters of the Moon National Monument, Idaho and the Columbia Hills of Gusev Crater, Mars Details Meeting 2016 Fall Meeting Section Planetary Sciences Session Terrestrial Analogs for Planetary Processes: Oceans, Volcanoes, Impacts, and Dunes I Identifier P31E-01 Authors Haberle, C W*, Mars Space Flight Facility, Arizona State University, Tempe, AZ, United States Hughes, S S, Idaho State University, Idaho Falls, ID, United States Kobs-Nawotniak, S E, Department of Geosciences, Idaho State University, Idaho Falls, ID, United States Christensen, P R, Arizona State University, Tempe, AZ, United States Index Sediment transport [4558] Terms Atmospheres [5405] Titan [6281] Venus [6295] Abstract Idaho's Eastern Snake River Plain (ESRP) is host to extensive expressions of basaltic volcanism dominated by non evolved olivine tholeiites (NEOT) with localized occurrences of evolved lavas. Craters of the Moon National Monument (COTM) is a polygenetic lava field comprised of more than 60 lava flows emplaced during 8 eruptive periods spanning the last 15 kyrs. The most recent eruptive period (period A; 2500-2000 yr B.P.) produced flows with total alkali vs. silica classifications spanning basalt to trachyte. Coeval with the emplacement of the COTM period A volcanic pile was the emplacement of the Wapi and Kings Bowl NEOT 70 km SSE of COTM along the Great Rift. Previous investigations have determined a genetic link between these two compositionally distinct volcanic centers where COTM compositions can be generated from NEOT melts through complex ascent paths and variable degrees of fractionation and assimilation of lower-middle crustal materials. The Mars Exploration Rover, Spirit, conducted a robotic investigation of Gusev crater from 2004-2010.
    [Show full text]