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Minerals of charnockites from IndiaNaidu, Purma Rangashayee Jagapathym, January 1955 (has links)
Thesis--Basel. / "Reprinted form 'Schweizerische Mineralogische und Petrographische Mitteilungen' Bd. 34, Heft 2, 1954." Stamped on cover: Arbeiten aus dem Mineralogisch-petrographischen Institut der Universität Basel. No. 18, Ser. III. eContent provider-neutral record in process. Description based on print version record.
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Minerals of charnockites from IndiaNaidu, Purma Rangashayee Jagapathym, January 1955 (has links)
Thesis--Basel. / "Reprinted form 'Schweizerische Mineralogische und Petrographische Mitteilungen' Bd. 34, Heft 2, 1954." Stamped on cover: Arbeiten aus dem Mineralogisch-petrographischen Institut der Universität Basel. No. 18, Ser. III. Also issued in print.
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Tectonic evolution of the west-central portion of the Newton window, North Carolina Inner Piedmont timing and implications for the emplacement of the Paleozoic Vale charnockite, Walker Top Granite, and mafic complexes /Byars, Heather E. January 2010 (has links)
Thesis (M.S.)--University of Tennessee, Knoxville, 2010. / Title from title page screen (viewed on July 20, 2010). Thesis advisor: Robert D. Hatcher, Jr. Vita. Includes bibliographical references.
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The Crustal Evolution of Nilgiri Block, Southern India : A Study on Archean Tectonics and Crustal GrowthSamuel, Vinod Oommen January 2015 (has links) (PDF)
The oldest dated rocks from the Acasta gneisses of the western Slave Province, Canada present an igneous age of ~4030 Ma. Following this the detrital zircons from the Jack Hills, Narryer Gneiss Terrane, Yilgarn Craton, Western Australia are identified as 4404 ±8 Ma. These discoveries suggest that crustal formation started as early as the Priscian Eon. Hitherto the Earth has gone through a series of interactions involving the atmosphere, hydrosphere, crust, mantle and core. However, only limited remnants of these early processes remain on the accessible crust due to extensive crustal reworking. The Southern Granulite Terrane (SGT) in the southern part of India represents the most extensive exposure of lower crustal granulite terranes in the world. This study mainly focuses on the characteristics of Archean (~2500 Ma) tectonics and nature of subsequent crustal growth, which led to the formation of Archean Nilgiri Block. Detailed fieldwork in this terrane and subsequent petrographic analysis revealed charnockites, hornblende-biotite gneiss, metagabbro/mafic granulite, websterite, amphibolite, Grt-Ky metasediment, metatuff and banded iron formation as the main rock types in this terrane. Field and petrographic results show a regional trend with garnet-orthopyroxene-biotite-quartz-plagioclase-K- feldspar bearing charnockites in the southern part which gets subsequently enriched in clinopyroxene that forms garnet-absent two pyroxene granulites consisting of orthopyroxene-clinopyroxene-quartz-plagioclase-K-feldspar towards the central part. Further north, metagabbro/mafic granulite is enriched in garnet-clinopyroxene-plagioclase assemblage. Websterite, amphibolite, metasediment, metatuff and banded iron formation are stacked and closely associated within this mafic belt in the north. The metagabbro represents peak P-T conditions of ~850°C and ~14kbar compared to the charnockites, which recorded a peak P-T of ~850°C and 9-10kbar. Petrographic results of oxide minerals show that the southern charnockitic part is abundant in rutile-ilmenite association represent reduced conditions compared to the oxidized magnetite-hematite-ilmenite associations in the mafic rocks. This oxidation trend is followed by pyrrhotite-chalcopyrite enriched southern charnockitic region that transforms to pyrite rich northern mafic belt. Ilmenite¬titanite association with no sulphides characterizes the hornblende-biotite gneiss in the entire Nilgiri Block. The geochemical variations of major, trace and rare earth elements show that the granulite-amphibolite grade felsic rocks evolved in an arc magmatic process leaving behind mafic magma, which later intruded into these rocks, in a subduction related arc magmatic process. The U-Pb LA-ICPMS and SHRIMP dating of charnockite, hornblende-biotite gneiss and met gabbros shows ca. 2550 Ma formation age and ca. 2450 Ma metamorphism in this terrane.
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Igneous and metamorphic charnockitic rocks in the Southern Marginal Zone of the Limpopo Belt with special emphasis on the Matok Enderbitic - Granatic Suite.Bohlender, Frank 04 June 2014 (has links)
D.Phil. (Geology) / Please refer to full text to view abstract
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