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Showing 1 to 20 of 32 for “"Island Arc"”.
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Geochemistry of boninites and other low TiO2 island arc volcanic rocks
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1983.
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Controls of Melt Genesis and Evolution at Buldir Volcano in the Western Aleutian Island Arc
… the westernmost emergent volcano in the Aleutian island arc, to investigate the role of amphibole fractionation versus source variability in the genesis of andesites and dacites from Buldir. Buldir lavas range from basalt to dacite and define a strongly calc-alkaline or low-Fe igneous series. …
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Petrological and geochemical study of spilites and associated dike rocks from the Virgin Island core (Caribbean Island arc)
… feet that was taken at St. John, U. S. Virgin Islands. The present study is confined to the upper 1180 feet and comprises a cummulative total of 950 feet of albitized mafic extrusive rocks (spilite). This portion of the core is also intruded by four dikes: two amphibole porphyryes (129-13h and …
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Pluton source varition over two magmatic pulses in the White-Inyo range, central-eastern California : implications for paleozoic and mesozoic tectonic reconstructions
… easternmost extent of the Mesozoic Cordilleran arc and the western edge of Basin and Range extension. The main goal of this dissertation is to understand the lithospheric structure of this area in relation to the broader regional tectonics. Chapters 2 and 3 specifically investigate the Eureka …
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Paleocene Turbidite Deposition in the Central American Seaway (NW Costa Rica): Geochemical Analysis and Provenance of Detrital Spinel and Clinopyroxene
… patterns. Modern Costa Rica is part of the island arc that formed over the western Caribbean subduction zone, and the Santa Elena peninsula is on the northwest coast of Costa Rica next to the Sandino forearc basin. This study focuses on the origin and provenance of the Paleocene deep water …
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Lithofacies, provenance, and diagenesis of jura-cretaceous strata of the Northern Bowser Basin, British Columbia
… of the sandstone suggests an obducted island arc and oceanic crust asprovenance. Three petrofacies have been identified by modal analysis of framework grains. Petrofacies 1(P1), which occurs in undivided Bowser Lake Group and Currier Formation strata, (QtFL = 34-14-52;QmFLt = 9-14-77) …
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The Determination of Lithospheric Rheology and Long-Term Interplate Coupling in Japan: Finite Element Modeling
… approximately perpendicular to the strike of the island arc, 2-D finite-element modeling can be used to examine the deformation over time of the island-arc lithosphere. The model geometry is based on geophysical and geological data, and each model run requires an assumed rheology and interplate …
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Distribution of Platinum Group Elements in the New Afton Alkalic Cu-Au Porphyry Deposit, Kamloops, British Columbia
… Kamloops, British Columbia, within the Quesnel island arc terrane, a Late Paleozoic to Mesozoic arc complex that occupies the eastern part of the Intermontane Belt of the Canadian Cordillera. Bulk rock and sulfide minerals from New Afton contain potentially economic concentrations of platinum …
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The tectonic relationships of the Hillabee Chlorite Schist and the adjacent rock units in southern Cleburne County, Alabama
… analysis indicates the origin to be in an island arc environment. The Coosa Block is thrust over the Talladega clock. The Hollins line fault is the contact between the Talladega and Coosa Blocks. The Coosa Block is composed of high grade Amphibolites facies rocks. Mica Schist with garnet …
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Petrological insights into pre- and syn-eruptive degassing at Ambrym volcano, Vanuatu
… processes at Ambrym volcano, a basaltic island arc volcano recently identified as a prodigious emitter of volcanic gases. Typical activity at this volcano entails heavy degassing from quasipermanent lava lakes, with Strombolian activity of fluctuating intensity. This is punctuated on an …
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The Analysis of the Shonen Protagonist and Aragoto Warrior: The Eternal Strength of Boyhood
… and the narrative structure of the Wano Country Island Arc of the story. The final section is dedicated to visual styles that are less direct, and a breakdown of specific narrative events and character archetypes represented in both pieces. This analysis not only shows the interesting overlap …
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STRUCTURAL AND KINEMATIC INVESTIGATION OF THE DADEVILLE COMPLEX-BREVARD ZONE CONTACT (SOUTHERN APPALACHIANS): POLYPHASE EMPLACEMENT OF AN ALLOCHTHONOUS TERRANE ON THE LAURENTIAN MARGIN
… and western Georgia. The DC formed as a volcanic island arc during the Taconic orogeny (Ordovician Period) and was accreted onto Laurentia during the Acadian orogeny (Devonian-Mississippian Periods); however, the mechanism and role of accretion during the Acadian orogeny is not well constrained. …
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Thermal Modeling of Cooling Time of Submarine Dacite Lapilli Tuff: Brothers Volcano, Kermadec Arc
… even though they are essential to developing island arc systems and represent the second largest volcanic systems on Earth. Scientific drilling allows for the opportunity to study these systems. This study focused on two drill sites on Brothers volcano from IODP Expedition 376: Site U1528, …
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Continental Arc Processes in British Columbia and Earthquake Processes in Virginia: Insights from Seismic Imaging
… the batholith complex and the accreted Stikine island arc terrane. The P and S wave models demonstrate a high-velocity (P 7.0 km/s, S 3.8 km/s) layer in the lower crust beneath the youngest (late Cretaceous to Eocene) portion of the continental arc complex. In contrast, the lower crust under the …
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Geology of the Ajax East and Ajax West, silica-saturated alkalic copper-gold porphyry deposits, Kamloops, South-Central British Columbia
… in the Nicola Group, a well defined volcanic island arc package. Pit mapping delineated eleven significantly different rock units: Nicola Group volcanic rocks, picrite and nine intrusive units ranging in composition from diorite or gabbro to quartz monzonite. The Ajax deposits occur at the …
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The geology and geochemistry of a Robinson Creek gold ocurrence, north of Amisk Lake, Saskatchewan
… 1982) and perhaps from an ocean floor to an island arc setting (Stauffer, 1974). However, all of the rocks in the area have been affected by several phases of deformation and are metamorphosed to greenschist to lower amphibolite grade. Chemical alteration of the rocks has been enhanced be …
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Geochemistry and petrology of the Lake Vermilion Formation, Ely Greenstone Belt, northeastern Minnesota
… Vermilion Formation basalts display a volcanic arc basalt trend of constant Ti02 with increasing Zr, similar to low-K tholeiites of the island arc tholeiitic series. The few Lower Ely basalt .samples are similar. The Upper Ely samples display a trend of increasing Ti~ with increasing Zr, similar …
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Geochemical investigation of Meso- to Neoarchean (3075–2800 Ma) supracrustal rocks in the Nuuk region, southern west Greenland
… rocks, and geodynamic setting. The Mesoarchean Ivisaartoq belt underwent two stages of calc-silicate alteration. Stage-I alteration appears to have resulted from sea-floor hydrothermal alteration. Stage-II alteration was developed during the regional metamorphism. Both stages of …
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Historic and prehistoric volcanic activity on St Kitts and Nevis, West Indies: Controls on future hazard
… lie in the northern part of the Lesser Antilles island arc, an archipelago formed by the subduction of the North American plate beneath the Caribbean plate. An integrated approach was undertaken to understand the most recent volcanic activity on the islands, and to assess likely future eruption …
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Investigation of the upper mantle as a source for contribution to magnetic anomalies
… examines the mantle wedge beneath multiple island arcs. Magnetic anomalies in island arc settings have been attributed to a serpentinized mantle wedge. While this material is not available to test, metasomatized mantle, common to the mantle wedge, is available. Metasomatized mantle is mostly …
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