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Showing 1 to 19 of 19 for “"anorthosite"”.
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On the carbothermic reduction of anorthosite
Includes bibliographical references (pages 197-210).
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Economics of alumina production from the Laramie Range anorthosite, Albany County, Wyoming, The
Includes bibliographical references (pages 92-95).
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Geology of the Piney River-Roseland titanium area, Nelson and Amherst counties, Virginia
… mapped area is underlain by a mass of pegmatitic anorthosite, about which other mappable rock units are distributed more or less peripherally. The chief units, listed from oldest to youngest, are: augen gneiss, biotite pencil gneiss, biotite aplitic gneiss, granitic gneiss, feldspathic gneiss, …
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Ore breakage characterisation of UG2 deposits using the JK RBT
… of UG2 chromitite, pyroxenite, spotted anorthosite and mottled anorthosite grab samples from run-of-mine (RoM) ore stockpile (particle selection method) and cut drill core particles (cut core method). A mineralogical analysis of UG2 chromitite, pyroxenite, spotted anorthosite and mottled …
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Petrogenesis of the Mesoproterozoic anorthosite, syenite and carbonatite suites of NW Namibia and their contribution to the metasomatic formation of the Swartbooisdrif sodalite deposits
… fluids and the neighbouring and incorporated anorthosites led to the formation of economically important sodalite deposits. Investigated anorthosite samples display the magmatic mineral assemblage of Pl (An37-75) ± Ol ± Opx ± Cpx + Ilm + Mag + Ap ± Zrn. Ilmenite and pyroxene are surrounded by …
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Anorthositic sills of the southern Adirondack Mountains of New York state
… The Speculator Sheet consists of gabbroic anorthosite and has a mafic lower margin due to gravitational settling of mafic phases. Plagioclase and pyroxene compositions suggest that the Wells gabbro is distinct from the rest of the sills and is related to the Oregon Dome. Whole rock data …
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Petrology and contact relationships, SW portion PC Mullen Creek mafic complex, Medicine Bow Mts., Wy.
… rocks that originally ranged from pyroxenite to anorthosite but were dominantly gabbro and leucogabbro. Most of these rocks underwent regional medium-grade metamorphism to form amphibolite facies assemblages in which hornblende has replaced pyroxene, labradorite has remained stable and relict …
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Petrology and tectonic setting of relatively low temperature eclogites and related rocks in the Dalsfjord area, Sunnfjord, West Norway.
… basic intrusions typical of mid-Proterozoic anorthosite suites.
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Petrographic Analysis of an Early Cenozoic Breccia from the Tinton Area, Northern Black Hills, South Dakota
… amphibolite, monzonite porphyry, metamorphosed anorthosite, quartz latite, muscovite-biotite? schist?, graphite schist, and a separate category of highly altered clasts. The clasts are 0.1 to 10 cm in diameter; they are well mixed and many are rounded. Both clasts and matrix are hydrothermally …
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Geochemical characteristics and rare earth element trends of the Upper Zone in the western Bushveld Complex
… gabbro, magnetite gabbro, lesser magnetite and anorthosite layers. Plagioclase comprises 50 to 70 volume percent of most samples investigated. Up to 87 volume percent plagioclase is found in anorthosite while magnetitite layers consist of up to 97 volume percent oxide. Unlike the eastern …
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The noble gas record of terrestrial and meteoritic samples
… noble gases in a 3.3 x 10<sup>9</sup> year old anorthosite from Greenland revealed isotopic anomalies of krypton and xenon which could be accounted for by a combination of two effects,</p> <ol> <li>a selective enrichment of the heavy isotopes by mass fractionation, and</li> <li>an enrichment of …
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STRUCTURAL, THERMOCHRONOLOGICAL, AND STRATIGRAPHIC CONSTRAINTS ON THE EVOLUTION OF THE CLEARWATER METAMORPHIC CORE COMPLEX, IDAHO
… internal zone that consists of Paleoproterozoic anorthosite and basement schist, and an external zone that consists of Archean to Paleoproterozoic intrusive bodies, basement metasediments, and metasediments of the Mesoproterozoic Belt Supergroup. This thesis is focused on constraining the …
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STRUCTURAL, THERMOCHRONOLOGICAL, AND STRATIGRAPHIC CONSTRAINTS ON THE EVOLUTION OF THE CLEARWATER METAMORPHIC CORE COMPLEX, IDAHO
… internal zone that consists of Paleoproterozoic anorthosite and basement schist, and an external zone that consists of Archean to Paleoproterozoic intrusive bodies, basement metasediments, and metasediments of the Mesoproterozoic Belt Supergroup. This thesis is focused on constraining the …
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EVOLUTION OF THE EASTERN ALPS FROM THE PALEOZOIC ONWARD: CONSTRAINTS AND INSIGHTS FROM THE (ULTRA)BASIC ECLOGITIC COMPLEX OF MILCHENKAR ÖTZTAL-STUBAI COMPLEX (EASTERN ALPS, TYROL, AUSTRIA)
… analyses on preserved olivine gabbro, anorthosite and pegmatoid gabbro samples allowed to infer the main crystallization processes, conditions of intrusion and main geochemical features of the parental melt. Olivine gabbros are the most primitive products and are characterized by the …
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A coming together: The juxtaposition of the Rae and Hearne cratons along the Virgin River shear zone (Snowbird tectonic zone), Saskatchewan, Canada, and the implications for proto-Laurentia
… Careen Lake group. The ca. 2110 Ma Clearwater anorthosite complex and a swarm of mafic dykes intruded the Taltson basement complex near the Virgin River shear zone. These rocks were intruded by continental volcanic arc plutons between 1.99 and 1.97 Ga, indicating a convergent tectonic setting …
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Metamorphic evolution of ultrahigh-temperature granulite facies and upper amphibolite facies rocks of the Epupa Complex, NW Namibia
… The rocks of the EC are transsected by a large anorthosite massif, the Kunene Intrusive Complex (KIC). The Orue Unit and the Epembe Unit were affected by two distinct Mesoproterozoic metamorphic events, as is evident from differences in their metamorphic grade, in the P-T paths and in the age of …
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An investigation into the complementary capabilities of X-ray computed tomography and hyperspectral imaging of drill core in geometallurgy
… less altered rocks (feldspathic pyroxenite and anorthosite) than the more altered rocks (altered harzburgite and pegmatoidal pyroxenite). The high scanning resolution allowed for the extraction of mineral texture, such as mineral association and grain size distribution (GSD). The 3D XCT derived …
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A petrographical and mineralogical investigation of the rocks of the Bushveld Igneous Complex in the Tauteshoogte-Roossenekal area of the Eastern Transvaal
… study has revealed the presence of a mineralized anorthosite below Lower Magnetitite Seam 2 which contains in places up to 1 per cent Cu, 0, 18 per cent Ni and 1, 6g/ton platinum metals. Continuous, slow convection and bottom crystallization probably gave rise to the homogeneous rocks of the Main …