 | | Journal (article/letter/editorial) | | 255 -28 6 J U N E 29, 1915 OBSIDIAN FROM HRAFNTINNUHRYGGUR, ICELAND: ITS LITH OPH YSiE AND SURFACE............................... 255 The Hrafntinnuhryggur obsidian.................................. .....best examples of which have been found in the obsidian of Yellowstone National Park. These were studied...February 13, 2016 25(5 F. E. WRIGHT----OBSIDIAN FROM ICELAND in accord, as to the genesis of the lithophysae...Iddings found “that the lithophysae in the obsidian of Obsidian Cliff, with their contents of prismatic |  | Ryan, A. G., Russell, J. K., Nichols, A. R. L., Hess, K.-U., Porritt, L. A. (2015) Experiments and models on H2O retrograde solubility in volcanic systems. American Mineralogist, 100 (4) 774-786 doi:10.2138/am-2015-5030 | Journal (article/letter/editorial) | | rhyolitic obsidian from Hrafntinnuhryggur, Krafla, Iceland, under atmospheric pressure. The obsidian is bubble-...crystal-free with an H2O content of 0.11(4) wt%. The obsidian cores were heated above the glass transition temperature...high-temperature (T) experiments wherein cores of obsidian are heated isothermally above the glass transition...experiments use rhyolitic obsidian from Hrafntinnuhryggur, Krafla, Iceland, as described and chemically...(2009) (Table 1). Their work showed the Hrafntinnuhryggur obsidian sampled from a <0.05 km3 outcrop to have |  | Castro, Jonathan M., Cottrell, Elizabeth, Tuffen, Hugh, Logan, Amelia V., Kelley, Katherine A. (2009) Spherulite crystallization induces Fe-redox redistribution in silicic melt. Chemical Geology, 268 (3) 272-280 doi:10.1016/j.chemgeo.2009.09.006 | Journal (article/letter/editorial) | | September 2009 Editor: D.B. Dingwell Keywords: Obsidian Spherulite Oxidation–reduction FTIR XANES a b...a c t Rhyolitic obsidians from Krafla volcano, Iceland, record the interaction between mobile hydrous...set in a glassy matrix (Fig. 1). They occur in obsidian domes, vitrophyric ash-flow tuffs (e.g., Smith... 1992; Tuffen et al., in review), spherulitic obsidian develops in spatially restricted zones (e.g.,...of spherulites (round and elliptical, black) in obsidian (brown). Various analytical points and traverses |  | | Journal (article/letter/editorial) | | Field Meeting. Proc. Geol. Ass., 99(3), 221-48. Iceland is probably the product of irregular diapiric upwelling...London Department of Extra-Mural Studies, visited Iceland between 23rd July and 2nd August, 1986. Regular...Nyidalur was spent in the tourist hut. Roads in Iceland are usually marked by posts but it is rare for...221 222 MICHAEL BAMLETr AND JOHN F. POTTER ICELAND ------66·n ---6S'n ~o 190 Km Key to daily...basaltic lavas are quenched by contact with water. In Iceland, the contact with water occurred because lavas |  | Castro, J. M., Beck, P., Tuffen, H., Nichols, A. R.L., Dingwell, D. B., Martin, M. C. (2008) Timescales of spherulite crystallization in obsidian inferred from water concentration profiles. American Mineralogist, 93 (11) 1816-1822 doi:10.2138/am.2008.2904 | Journal (article/letter/editorial) | | 2008 Timescales of spherulite crystallization in obsidian inferred from water concentration profiles Jonathan...Krafla volcano, Iceland. We measured water concentration profiles around spherulites in obsidian by synchrotron...spherulites. Keywords: Spherulite, diffusion, obsidian, crystallization introduCtion The rates and timescales...timescales of small spherical crystal aggregates in obsidian, known as spherulites (Fig. 1). We present synchrotron...water concentration profiles around spherulites in obsidian. We then model the concentration profiles by numerically |  | | Report (issue) | | Occurrence: As acicular crystals in lithophysae in obsidian (Lake Naivasha, Kenya). Association: Anorthoclase...California; and at Obsidian Cli®s, Yellowstone National Park, Wyoming. From Hrafntinnuhryggur, Iceland. Name: For |  | | Journal (article/letter/editorial) | | starting materials are cores of natural rhyolitic obsidian synthesized to have variable vesicularity (φ =...natural hydrous rhyolitic obsidian from Hrafntinnuhryggur, Krafla, Iceland (Tuffen and Castro, 2009)....Composition (wt.%) of obsidian (ρ = 2.394 g cm−3 ) from Hrafntinnuhryggur, Krafla, Iceland (Tuffen and Castro...◦ C) as measured calorimetrically on original obsidian (Castro et al., 2008). (For interpretation of...calorimetrically measured T g (690 ± 20 ◦ C) for the obsidian (Castro et al., 2008). MP results for the hydrous |  | | Journal (article/letter/editorial) | | growing in cristobalite-lined lithophysae in black obsidian from Coso Hot Springs, Inyo County, California...Sci. 9,43-46. Wright, FE., 1915. Obsidian from Hrafntinnuhryggur, Iceland: Its lithophysae and surface markings |  | Wadsworth, Fabian B., Vasseur, Jérémie, Schauroth, Jenny, Llewellin, Edward W., Dobson, Katherine J., Havard, Tegan, Scheu, Bettina, von Aulock, Felix W., Gardner, James E., Dingwell, Donald B., Hess, Kai-Uwe, Colombier, Mathieu, Marone, Federica, Tuffen, Hugh, Heap, Michael J. (2019) A general model for welding of ash particles in volcanic systems validated using in situ X-ray tomography. Earth and Planetary Science Letters, 525. 115726 doi:10.1016/j.epsl.2019.115726 | Journal (article/letter/editorial) | | sintering porosity surface tension tuffisite jet engine obsidian a b s t r a c t Welding occurs during transport...glass collected from Hrafntinnuhryggur, Krafla (Iceland). We crushed the obsidian to a powder using an...(g) The porosity as a function of time of the obsidian particles sintered in situ using time-resolved...methods to image the evolution of a welding pack of obsidian powder, lightly pressed into a free-standing cylinder...Source at the Paul Scherer Institute. Cylinders of obsidian powder were loaded into the imaging window of |  | | Journal (article/letter/editorial) | | to the Pre-Cambrian geology of the Lake Superior region. The elder Wright died at an early age in 1888'...B ull. 259, 47-68 (1905). The Unuk River mining region of British Columbia Geol,.Sowa. Canad'a, Summary...191-192 (1910). Some effects of glacial action in Iceland: Geol.Soc. Amer., BuJl.,2l, 717-730 (lglD). (and...Acad'. Sci.,5, 101-107 (1915). Obsidian from Hrafntinnuhryggur, Iceland: Its lithophysae and surface markings:...(1916). Note on the lithophysae in a specimen of obsidian from California: f ow. Waslt' Aca.d. Sci ', (t9r6) |  | | Journal (article/letter/editorial) | | infinite sheet, following the equations for an infinite region with two boundary condition temperatures (equation...(i.e. tholeiitic) composition of Hrafntinnuhryggur, Krafla, Iceland, reported in Table A3 (Ryan et al...relevant for permeability retention, is a narrow region of the deposit near the conduit wall. Since anything...Germany Torfajokull, Iceland Torfajokull, Iceland Torfajokull, Iceland Torfajokull, Iceland Unzen, Japan Unzen...Unzen, Japan <0.1 <0.03 Obsidian Φ < 0.1 Obsidian Φ < 0.1 Andesite Φ > 0.8 Andesite Φ > 0.8 Andesite |  | | Journal (article/letter/editorial) | | are best named on the basis of (i) structure, as obsidian, pumice, perlite, tuff; and (2) composition, indicated...composition, rhyolite pumice, dacite perlite, andesite obsidian, etc. Pitchstones generally have a high content...or composition estimated: i. Obsidian, Hrafntinnuhryggur, Krafla, Iceland. F. E. Wright, Bull. Geol. Soc...Soc. Am., Vol. XXVI (1915), p. 260. 2. Obsidian (biotite-soda rhyolite of Sitgreave's Peak), San Francisco...phenocrysts of orthoclase, apatite, and zircon. 4. Obsidian, Millard County, Utah. W. Cross, U.S. Geol.Surv |  | | Journal (article/letter/editorial) | | ])art 4] TERTIARY~'OLCANIC SERIES OF EASTERN ICELAND. 22. 549 OJt a n OLIVINE-DxcITE [n [,]te TERTIARY...tile Tertiary basalt-plateau of South-Eastern Iceland. A mass of acid rock occurring in a district entirely...Plant-lCmains found at various horizons in Eastern Iceland indicate a Tertiary age for the lavas ; but no...that provides the habitable part of the Hamarfjord region. With the exception of a few quartz-porphyry and...At the eastern end is a wall of black and green obsidian and pitchstone, 500 feet high, and commonly 6 |  | Casas, Ana S., Wadsworth, Fabian B., Ayris, Paul M., Delmelle, Pierre, Vasseur, Jérémie, Cimarelli, Corrado, Dingwell, Donald B. (2019) SO2 scrubbing during percolation through rhyolitic volcanic domes. Geochimica et Cosmochimica Acta, 257. 150-162 doi:10.1016/j.gca.2019.04.013 | Journal (article/letter/editorial) | | by a crystal-free obsidian emplaced at Hrafntinnuhryggur, Krafla volcano, Iceland. The glass sample corresponds...mechanism for degassing and origin of silicic obsidian. Geology 39, 67–70. Carn, S.A., Clarisse, L.,...Hofmann, A.W. (1978). Diffusion of Sr, Ba and Na in obsidian. Geochim. Cosmochim. Acta 42, 595-605. Maters...emplacement of an obsidian dyke through thin ice: Hrafntinnuhryggur, Krafla Iceland. J. Volcanol. Geotherm...electron microscope images of the typical crushed obsidian particles used in this study (a) prior to exposure |  | | Journal (article/letter/editorial) | | PETROGENETIC RELATIONSHIPS OF ACID AND BASIC ROCKS IN ICELAND: Sr-ISOTOPES AND RARE-EARTH ELEMENTS IN LATE...National Energy Authority, Laugavegur 116, Reykjavik, Iceland Received 28 March 1973 Revised version received...basalts in Iceland. Late and postglaeial basalts in Iceiand have been generated from a source region which...activity in Iceland has been concentrated in two main active belts (fig. 1), one in the west of Iceland and one...across Iceland, and fades out north o f Langjokull in central Iceland. In the north of Iceland the eastern |  | | Journal (article/letter/editorial) | | in Iceland JEFFREYA. CODERRE* and SIGURDURSTEINTHC~RSSON Science Institute, University of Iceland, Jardfraedahus...Jardfraedahus Reykjavik, Iceland Haskblans, (Received 25 May 1976; accepted in revised form 24 September...bution and geochemical behaviour of mercury in Iceland. The data may be grouped into four main classes:...indicate the baseline mercury concentration in Iceland; (2) atmospheric samples taken during a volcanic...high atmospheric mercury concentrations all over Iceland, especially at geothermal areas. The reported data |  | | Report (issue) | | references (p. ) Supt. of Docs, no.: I 19.16:1523 1. Obsidian Composition. I. Smith, Robert L. II. Thomas, John...the occurrence, geology, and petrography of the obsidian subgroups Group I: Obsidians from the early stages...47 48 50 51 Application to the whole body of obsidian data Magma mixing and assimilation Vapor-phase...discrimination plots Geochemical features of main obsidian groups Group I: Obsidians from primitive island...and orthoclase showing fields and averages for obsidian on*Aiir*c .........__........___............. |  | | Journal (article/letter/editorial) | | New Zealand. It consists of several lobes of obsidian of homogeneous chemical composition and low initial...calorimetric properties and textures of the rhyolitic obsidian (Ng 10-7) are assessed and the order in which...mechanism for degassing and origin of silicic obsidian. Geology 39, 67–70. Castro J. M., Beck P., Tuffen...(2008) Timescales of spherulite crystallization in obsidian inferred from water concentration profiles. Am...Dingwell D. B. (2011) Paleointensities of phonolitic obsidian: influence of emplacement rotations and devitrification |  | | Journal (issue) | | in the West are Berkeley Hills and the fv\ojave region in California; Virgin Vo lley, Beatty, Coyote Spr...centers in a glass. These structures are common in obsidian, rhyolite, and vitric tuffs. One of thedetails...lithophysae was made by Wright (1915) on obsidian from Iceland. He discusses the two theories for the origin... p. 3-6. Wright, F. E., 1915, Obsidian from Hrafntinnuhryggur, Iceland; its lithophysae and surface markings:...Australia, Belgium, Canada, Czechoslovakia, England, Iceland, Norway, South Africa, and West Germany joined |  | | Journal (issue) | | and stretching along the Leba dunes and Gdansl< region, they reach the Vistula Spit beyond Krynica Morska...Carson I. A. Ritchie ICELAND SfR RUKJAVI HOLSMYRI VIK There are no rockshops in Iceland. You have to visit...collecting. This is a very pleasurable experience. Iceland is so undeveloped that every thing offers the...originated. . Because of its very long coastllne, Iceland offers particularly fine beaches, such as the splendid...beautifully shaped basalt pebbles One particular gem, Iceland Spar, is unique to the country. Others, such as |  | | Journal (article/letter/editorial) | | System of Krafla, NE Iceland Knútur Árnason ÍSOR, Iceland GeoSurvey, 108 Reykjavík, Iceland; Knutur.Arnason@isor...Krafla volcano is the most studied volcano in Iceland. The onset of the Krafla Fires 1975–1984, often...volcano and its geothermal system(s). The Krafla region has long been known for its geothermal activity...build the first major geothermal power plant in Iceland in Krafla. The construction of a 60 MWe power plant...is located within the Northern Volcanic Zone of Iceland (Figure 1). The 2. Tectonic Setting Geology Ridge) |  | | Journal (article/letter/editorial) | | Accepted 6 October 2011 Keywords: Natural glass Obsidian Perlite Pitchstone Impactite Tektite Frictionite...Heide / Chemie der Erde 71 (2011) 305–335 2.1. Obsidian and pumice . . . . . . . . . . . . . . . . . ...produce tools and weapons. Natural glasses such as obsidian, the most frequent vitreous material on the earth’s...of weapons, decoration and mirrors. The use of obsidian determined the development of ancient civilizations...spanned trade in obsidian (e.g. Rapp, 2002, p. 79). The conchoidal fracture of obsidian allows for the |  | Masotta, M., Mollo, S., Nazzari, M., Tecchiato, V., Scarlato, P., Papale, P., Bachmann, O. (2018) Crystallization and partial melting of rhyolite and felsite rocks at Krafla volcano: A comparative approach based on mineral and glass chemistry of natural and experimental products. Chemical Geology, 483. 603-618 doi:10.1016/j.chemgeo.2018.03.031 | Journal (article/letter/editorial) | | at Krafla volcano during the perforation of the Iceland Deep Drilling Project Well 1 (IDDP-1). The perforation...magma batches from the mineral-liquid separation region (Masotta et al., 2016), or after the exhumation...(Wickham, 1987). NU The perforation operated by the Iceland Deep Drilling Project (i.e., IDDP-1) at the Krafla...the north of Iceland and is bisected by a NNE–SSW fissure swarm that marks the North Iceland Rift Zone (Figure...the 1975-1984 “Krafla Fires” and the 1724-1729 “Myvatn Fires” fissure eruptions associated to rifting |  | | Journal (article/letter/editorial) | | has shown that the rate of volcanic activity in Iceland accelerated by a factor of 30–50 following the...Explosive phreatomagmatic activity at Grímsvötn, Iceland, on 2 November 2004. Photograph by Matthew Roberts...Andes, the Cascades, the Aleutian–Kamchatkan arc, Iceland, Antarctica, Japan and New Zealand (figures 1 and...from a geothermally active zone high in the summit region adapted from Huggel (2009), photograph by R. Wessels...Wessels. (b) Map of Myrdalsjökull ice cap, Iceland, showing potential drainage directions of jökulhlaups |  | | Journal (issue) | | Bull. Geol. Soc. Am. 26, 255-286, Obsidian from Hrafntinnuhryggur, Iceland: its Lithophysae and Surface Markings |
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