 | | Journal (article/letter/editorial) | | earth element abundances in volcanic rocks from Guam: implications for the evolution of the Mariana Arc...33199, USA 2 Earth Science Board, University of California at Santa Cruz, Santa Cruz, CA 95064, USA Abstract...Abstract. Volcanic rocks exposed on Guam were erupted during the Late Middle Eocene (Facpi Fm.), Late...element (REE) data for volcanic rocks from Guam Island. Guam is the southernmost island in the Mariana...erupted between 44 and 14 m.y.b.p. The oldest lavas on Guam are the oldest dated rocks in the Mariana arc system |  | | Report (issue) | | of Guam I GEOLOGICAL [SURREY PROFESSIONAL PAPER 403-C Petrology of the Volcanic Rocks of Guam By...VOLCANIC ROCKS OF GUAM By JOSHUA I. TRACEY, JR., and JOHN T. STARK GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS...of the basaltic and andesitic volcanic rocks of Guam and their relations to similar rocks of Saipan and...Mineralogy.- ______ _______ _________ __ _________ Plagioclase feldspar _______ _____ ____ _ _ _____ Alkali...Petrogenes Trace elements in the volcanic rocks of Guam, by Joshua elen I. Tracey, Trace Jr., and John T |  | | Report (issue) | | Limestones of Guam GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-D Petrology of the Limestones of Guam By SEYMOUR...HATI-IAWAY and DOROTHY CARROLL GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS GEOLOGICAL SURVEY PROFESSIONAL...---------------------- Limestone formations of Guam ______________________ _ Limestone of Eocene (b)...the Alifan Limestone. Phosphatic limestone from Guam and from Anguar, Palau Islands. Limestone from the...from Kirkuk, Iraq. Insoluble residues from selected Guam Limestone. Page FIGURE 1. Columnar stratigraphic |  | Ishizuka, Osamu, Tani, Kenichiro, Reagan, Mark K., Kanayama, Kyoko, Umino, Susumu, Harigane, Yumiko, Sakamoto, Izumi, Miyajima, Yuki, Yuasa, Makoto, Dunkley, Daniel J. (2011) The timescales of subduction initiation and subsequent evolution of an oceanic island arc. Earth and Planetary Science Letters, 306 (3) 229-240 doi:10.1016/j.epsl.2011.04.006 | Journal (article/letter/editorial) | | Trowbridge Hall, University of Iowa, Iowa City, IA 52242, USA d Department of Earth Sciences, Kanazawa University... A forearc basalt from the Mariana forearc near Guam produced a similar 40Ar/39Ar age of 51.1 Ma. The...oceanic island arc extends from Honshu, Japan to Guam, and resulted from subduction of the Pacific Plate...volcanic front (Fig. 1A). This forearc high includes Guam, Rota, Tinian, and Saipan, where Eocene to Oligocene...explored the Mariana fore-arc to the southeast of Guam and investigated the volcanic stratigraphy of the |  | | Journal (article/letter/editorial) | | Tertiary basalts of island arc tholeiitic series in Guam by lower K: O and somewhat higher TiO: contents...Quartz Plagioclase Actinolite Hornblende Chlorite Epidote Sphene Ores Others An % of Plagioclase Actinolite...minerals are actinolite, chlorite, and sodic plagioclase. Persistent accessories include epidote, sphene...and/or CO2 pressures; calcite is almost absent. Plagioclase occurs in clear and homogeneous crystals about...green mm in size. The anorthite content of the plagioclase, as determined from refractive indices measured |  | | Report (issue) | | Soils from Guam GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-F Mineralogy of Selected Soils from Guam By DOROTHY... By CARL H. STENSLAND GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS GEOLOGICAL SURVEY PROFESSIONAL...mineralogical study of selected soil samples of Guam, including data on chemical composition, grain-size...volcanic rocks _ _ _ _ Asan clay on volcanic rocks_____ Guam clay on limestones _______ Fossil red latosol_____________...limestones__________________________ Comparison of soils of Guam with those of similar parentage in other selected |  | ISHIZUKA, O, KIMURA, J, LI, Y, STERN, R, REAGAN, M, TAYLOR, R, OHARA, Y, BLOOMER, S, ISHII, T, HARGROVEIII, U (2006) Early stages in the evolution of Izu–Bonin arc volcanism: New age, chemical, and isotopic constraints. Earth and Planetary Science Letters, 250 (1) 385-401 doi:10.1016/j.epsl.2006.08.007 | Journal (article/letter/editorial) | | 75083-0688, USA e Department of Geoscience, University of Iowa, Iowa City, IA 52242, USA f National Oceanography... Oregon State University, Corvallis, OR, 97331, USA Received 1 February 2006; received in revised form...Bonin Ridge. The basement of the forearc island of Guam consists of ca. 44 Ma [27] boninite series pillow...clinopyroxene (3–6%), orthopyroxene (1– 3%), plagioclase (5–40%) phenocrysts; they may also have Fe–Ti...textures are common, including complex zoning in plagioclase phenocrysts, clinopyroxene rimming orthopyroxene |  | Reagan, Mark K., McClelland, William C., Girard, Guillaume, Goff, Kathleen R., Peate, David W., Ohara, Yasuhiko, Stern, Robert J. (2013) The geology of the southern Mariana fore-arc crust: Implications for the scale of Eocene volcanism in the western Pacific. Earth and Planetary Science Letters, 380. 41-51 doi:10.1016/j.epsl.2013.08.013 | Journal (article/letter/editorial) | | Sciences, University of Iowa, Iowa City, IA 52242, USA Hydrographic and Oceanographic Department of Japan...University of Texas at Dallas, Richardson, TX 75083, USA b a r t i c l e i n f o Article history: Received...b s t r a c t The Mariana fore-arc southeast of Guam consists of ophiolitic lithologies related to subduction...trench slope of the Mariana fore-arc southeast of Guam (Fig. 1) are similar to those that make up many...seafloor spreading. One FAB from the fore-arc near Guam was dated at 51.1 ± 1.5 Ma * Corresponding author |  | | Journal (article/letter/editorial) | | University of Arizona, Tucson, Arizona, 85721, USA Abstract. Low-K rhyolites and overlying 2-pyroxene...of Saipan is one of a group of islands (including Guam, Tinian, Rota and several smaller islets) that represent...it has been studied (Saipan: Cloud et al. 1956; Guam: Tracey et al. 1963; Reagan and Meijer in press;...with predominantly basalts and andesites exposed on Guam (Tracey et al. 1963; Reagan and Meijer in press)...08 2.67 2.69 . - 2.96 0.94 0.32 . 2.94 Plagioclase ~ C-pyroxene d 11.7 11.2 3.46 0.81 - . . - |  | | Report (chapter) | | at Dallas, Box 830688, Richardson, TX 75083-0688, USA 2 Institute for Research on Earth Evolution (IFREE)...OR 97331, USA 5 Pacific Marine Environmental Laboratory/NOAA, Newport, OR 97365-5258, USA 6 ALS Geochemistry...Sciences, University of Delaware, Newark, DE 19716, USA *Corresponding author (e-mail: rjstern@utdallas.edu)...show arc-like associations of anorthite-rich plagioclase with Fe-rich olivine. Magmatic temperatures for...2800 km south from near Tokyo, Japan, to beyond Guam, USA (Fig. 1a), and is an excellent example of an intra-oceanic |  | | Journal (article/letter/editorial) | | locality for boninite, a high-Mg andesite lacking plagioclase phenocrysts and with exceedingly low concentrations...front (FIG. 1); this high includes the islands of Guam, Rota, stood (e.g. Stern 2004). Exposed “naked forearcs...Japan E-mail: o-ishizuka@aist.go.jp 115–120 -2000 Guam -4000 Mariana forearc 6K1093 3 Department of...Trowbridge Hall University of Iowa, Iowa City IA 52242, USA PP. 0 Saipan 15˚ 2 IFREE, JAMSTEC, 2-15 Natsushima...orthopyroxenebearing gabbros, predominantly composed of plagioclase, clinopyroxene, and orthopyroxene, with accessory |  | | Journal (article/letter/editorial) | | Al-rich chromite, phenocrystic hornblende, and plagioclase without pyroxene, suggesting a high water content...spessartites composed essentially of hornblencle, plagioclase, and augite. They, with some exception, exhibit...hornblende, actinolite, biotite, highly zoned plagioclase, orthoclase, and quartz, together with microphenocrysts...of idiomorphic augite set in a groundmass of plagioclase, orthoclase, quartz, and brown or green hornblende...fine-grained spessartite. In the groundmass plagioclase appears to have crystallized earlier than hornblende |  | | Report (issue) | | Primary minerals._-____________________-_-_---Plagioclase feldspar.________________________ Alkali feldspar...and dacites from Saipan and volcanic rocks from Guam, the Palau Islands, and the Bonin Islands______...____ 2. Specific gravity and composition of plagioclase feldspar phenocrysts from various andesites of...groundmass. The average chemical composition of plagioclase feldspar phenocrysts in several varieties of...of volcanic rocks from Saipan, 1 of andesite from Guam, and 5 of basalt from the islands of Alamagan, Pagan |  | | Journal (article/letter/editorial) | | erupted after boninites) from the Bonin Islands and Guam. The age-corrected (initial) Os isotope ratios of...from the Bonin Islands (0.1187–0.1254) and from Guam (0.1220–0.1269) are unradiogenic relative to primitive...and micro-phenocrysts of olivine, augite, and plagioclase. Cr-spinel and magnetite occurred as inclusions...revealed euhedral olivine, clinopyroxene and plagioclase phenocrysts and SC R microphenocrysts with...Mukoujima CE P 2.2 Samples from Guam TE D (Maehara and Maeda, 2004). Guam, an island at the southern end |  | | Journal (article/letter/editorial) | | olivine–clinopyroxene–orthopyroxene– plagioclase crystallization sequence. Coexisting plagioclase and clinopyroxene in...clinopyroxene phenocrysts, elongate orthopyroxene and plagioclase microphenocrysts. Highly phyric boninitic basalt...Groundmass consists of less than 0.3 mm long plagioclase microlites with swallow-tail terminations, spherulitic...glassy groundmass (plane polarized light). (g) Plagioclase, orthopyroxene and clinopyroxene microphenocrysts...tuff are marked by the presence of abundant plagioclase laths as glomerocrysts and sparse cpx with or |  | | Journal (article/letter/editorial) | | College Station, Duke University, Durham, NC 27708, USA 2 Geological Research Division, A-0t5, Scripps Institution...Institution of Oceanography, La Jolla, CA 92093, USA Abstract. Boninite series volcanic rocks have been...the dacites orthopyroxene, clinopyroxene, and plagioclase. Most of the major and trace element variation...of olivine, orthopyroxene, clinopyroxene, and plagioclase in the proportions 2.5:4:1:2, leaving 47% residual...reverse zoned phenocrysts, resorbed olivine and plagioclase xenocrysts, and bulk rock compositions which |  | | Journal (article/letter/editorial) | | and includes olivine and plagioclase or olivine, clinopyroxene and plagioclase as phenocrysts, respectively...ground masses consist of olivine, clinopyroxene, plagioclase, and iron-titanium oxide. All the chromian spinels...and contains olivine and plagioclase or olivine, clinopyroxene, and plagioclase. The groundmass consists...consists of olivine, clin opyroxene, plagioclase, and iron-titanium oxide, but in the aphyric basalt ortho...considerable amount of phenocrysts consisting of plagioclase, clinopyroxene, orthopyroxene, less amounts of |  | | Report (issue) | | entirely replace primary mafic minerals and plagioclase, respectively, and quartz and pyrite have been...nepheline basalts. sisting almost entirely of plagioclase, monoclinic Although the melilite-nepheline and...on Tol and Ulalu, make correlation tation of plagioclase laths. Most of the andesites have of individual...%-inch crystals characterize pegmatitic zones. Plagioclase forms between 50 and 80 percent of the gabbro...scarps such as are found in the eastern islands. Plagioclase, augite, and olivine are commonly recognizable |  | | Journal (article/letter/editorial) | | in the first part of the cruise between Tokyo and Guam and publish their results. A full geological compilation...Parece ~ Vela Basin ESE - Ridge Mariana Trough ~ | Guam (12°N) 1404 1403 1402 km L.. ~,:~:.-,~ ,, ~o...sedimentary records from the volcanic islands of Saipan, Guam and Palau, the volcanic activity started at least...montmorillonite/chlorite, ol = olivine, plag = plagioclase, preh = prehnite, qtz = quartz, serp = serpentine...investigated [16]: the more central part southeast of Guam (stations 1402-1404) and the western end at the |  | | Report (issue) | | Marine Geology of Guam GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-B Marine Geology of Guam By K. O. EMERY...EMERY GEOLOGY AND HYDROLOGY OF GUAM, MARIANA ISLANDS GEOLOGICAL SURVEY PROFESSIONAL PAPER 403-B A study...-_-_------------------5 3. Bathymetric chart of Guam and vicinity._________________________-______--...--10 8. Distribution of deep-sea sediments near Guam, compiled from various sources_-__--------_-----------------12... 13. 14. Description of samples from slopes of Guam.____________________________________________________________ | | | Report (issue) | | Occurrence of High Rates of Neurodegenerative Diseases on Guam and a Hypothesis for the Cause of the Diseases By...the Occurrence of Neurodegenerative Diseases on Guam…………………………………………………………..…………36 Acknowledgements…...rock types from Guam…………………….17 Table 2. Mean chemical composition of rocks from Guam compared to mean...Table 3. Chemical analyses and means of soils from Guam…………………………...………22 Table 4. Mean chemical composition...composition of soils from various rock types of Guam compared to mean soil developed on basalt from the western |  | | Journal (article/letter/editorial) | | Illinois at Chicago, PO Box 4348, Chicago, IL 60680, USA Abstract. Lavas and intrusives from Ayios Mamas...CaO-rich, SiO2-poor variant, resembling those from Guam, but contrasting with those from Bonin and Cape...recognized (Table l), the lowermost (A) has plagioclase, clinopyroxene, magnetite, and rare olivine (Fo86-ss)...(Fo86-ss) as phenocryst phases. Plagioclase is AnTs-ss and up to 3 mm long. Clinopyroxenes are colourless...groundmass of either fresh or altered glass with plagioclase microphenocrysts. The inferred crystallization |  | | Journal (article/letter/editorial) | | phenocryst phases clinopyroxene, orthopyroxene, plagioclase, and magnetite, and repeated subsequent mixing...Series (Lo-LTS), with phenocrystic clinopyroxene, plagioclase, and olivine, occurs in one or two highly dissected...aphyric to sparsely phyric with phenocrystic plagioclase, augite, hypersthene, pigeonite, and Fe-Ti oxides...olivine, clinopyroxene, chromian spinel, and rare plagioclase dominates the upper third of the extrusive crust...of pillow lavas and only minor massive lavas. Plagioclase is the dominant groundmass phase, although most |  | | Journal (article/letter/editorial) | | 002, and 20 percent consists of phenocrysts of plagioclase (75 percent), orthopyroxene (8 to 10 percent)...either optically or by X-ray techniques. The plagioclase occurs as fragments of euhedral grains in all...and X-ray determinations indicate a bimodal plagioclase population with maxima at An65 and An75. Both...Volcano (Kuno, 1962). (4) Sodic—Andesite Boulder from Guam (Stark, 1963). (5) Pumice from Huzi Volcano (Kuno...J. T., 1963, Petrology of the volcanic rocks of Guam, U.S. Geol. Survey Prof. Paper 403-C, 32 p. MANUSCRIPT |  | | Journal (article/letter/editorial) | | Florida International University, Mtaml, FL 33199, USA Recewed October 29, 1990, rewsed and accepted July...the modern Manana Trench' the Mariana Islands of Guam and Smpan and the submerged Mariana fore-arc (DSDP...Pb-lsotopes for comparison with values obtained from plagioclase and groundmass separates. Isotopic measurements...Volcano arcs (MVA) and Palau-Kyushu Arc lavas found on Guam and in the Manana fore-arc. Values for one West...originated from the Palau-Kyushu Arc, such as lavas from Guam and DSDP Site 458 and 459. The Site 448 samples |
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