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Journal Article
Published: 01 February 2022
Russ. Geol. Geophys. (2022) 63 (2): 137–152.
... of relict Paleoarchean (3.4 Ga) melanocratic granulites and predominant Neoarchean mafic and felsic granulites (2.70–2.66 Ga), paragneisses (≤2.75 Ga), and gneissic granites (2.54 Ga). The Paleoproterozoic complexes include paragneisses (1.95–1.85 Ga), granitoids and charnockites (1.86–1.84 Ga), as well...
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Journal Article
Journal: Geosphere
Published: 22 December 2021
Geosphere (2022) 18 (1): 298–326.
... grains from six paragneiss samples from the Skagit Gneiss and from two metapelite and two conglomerate samples from the meta-Methow were extracted using standard mineral-separation techniques. The entire zircon population from each sample was poured and mounted in epoxy to avoid bias in age populations...
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Journal Article
Published: 01 July 2021
American Mineralogist (2021) 106 (7): 1172–1182.
...Graciela Sosa; Sebastián Oriolo; Alfons van den Kerkhof; Pablo Diego González; Ezequiel Olaizola; Florencia Bechis Abstract Quartz segregations in paragneisses from the Paleozoic basement of the North Patagonian Andes contain highly saline multiphase fluid inclusions with the rare daughter mineral...
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Series: Geological Society, London, Memoirs
Published: 27 May 2021
DOI: 10.1144/M55-2018-51
EISBN: 9781786209863
... (V1) volcanic rocks of the southern Antarctic Peninsula are derived from the isotopically uniform magma, but they have mixed with melts of upper-crustal paragneiss in high-level magma chambers. The V2 rhyolites from the northern Antarctic Peninsula are the result of assimilation and fractional...
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Journal Article
Journal: GSA Bulletin
Published: 22 April 2021
GSA Bulletin (2022) 134 (1-2): 179–200.
... and lower arc crust, and the contributions of these rocks to the evolution of arc crust remain unclear. In this paper, we conduct a systematic study of petrology, geochronology, and geochemistry of migmatitic paragneisses from the eastern Gangdese magmatic arc, southern Tibet. The results show...
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Journal Article
Published: 26 February 2021
Canadian Journal of Earth Sciences (2021) 58 (10): 1027–1039.
... continued thermal activity during the Rigolet phase of the orogen that resulted in migmatization of paragneiss at ca. 1004 Ma and juxtaposition of upper- and mid-crustal rocks during orogenic collapse. The lithologic ages and tectonic history of the Trenton Prong correlate to those in other Appalachian...
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Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 08 February 2021
Lithosphere (2021) 2021 (1): 6697858.
... block, two garnet bearing paragneiss samples were analyzed. Petrographic thin sections were made from all samples. Zircons were separated from 8 granitoid samples, two paragneiss samples, and one aplitic dike sample using a jaw crusher, disc grinder, water table, magnetic separation, and heavy liquids...
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Journal Article
Published: 02 December 2020
Environmental & Engineering Geoscience (2021) 27 (1): 95–111.
.... The Gadria catchment is located in the Vinschgau-Venosta Valley, eastern Italian Alps, and belongs to the Adige River basin ( Figure 1a ). At the fan apex, the catchment has a drainage area of 6.3 km 2 and ranges in elevation from 1,394 to 2,945 m a.s.l. ( Figure 1b ). The Gadria is underlain by paragneiss...
Journal Article
Journal: GSA Bulletin
Published: 01 December 2020
GSA Bulletin (2021) 133 (7-8): 1483–1504.
... in early Earth. The Paleoproterozoic Aketashitage orogenic belt is located at a key position in northwestern China and connects the North China craton, Tarim craton, Altaids orogen, and Tethys orogen. Garnet-bearing mafic and paragneissic granulite occur as interlayers or blocks preserved within...
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Journal Article
Journal: GSA Bulletin
Published: 07 October 2020
GSA Bulletin (2021) 133 (5-6): 1021–1038.
..., the oldest rocks of which contain granulite-facies mineral assemblages and all of which are deformed. Leucopegmatites that intrude pelitic paragneisses, which likely formed in response to high-grade metamorphism and which are all deformed, are 370–355 Ma in age. All metapelitic paragneisses contain...
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Journal Article
Published: 10 September 2020
Mineralogical Magazine (2020) 84 (5): 662–690.
... of >900°C. The last preserved stages of retrogression are recorded in paragneiss plagioclase–garnet, biotite–garnet and host rock ilmenite–magnetite pairs (≤3 kbar and ~380–560°C). The Amikoq Complex intruded a MORB-like crustal section and the former remained relatively undisturbed in terms of modal...
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Journal Article
Published: 28 July 2020
Canadian Journal of Earth Sciences (2021) 58 (1): 21–37.
... is unclear (see text). Coordinate system for location is EPSG 4326 (WSG84). Sample BC04 is a dark, fine-grained, sillimanite-bearing garnet paragneiss that is composed mainly of biotite, quartz, and plagioclase. It crops out in a small siliceous schistose metasedimentary layer surrounded by alkali...
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Series: GSA Field Guide
Published: 18 May 2020
DOI: 10.1130/2020.0059(02)
EISBN: 9780813756592
.... The biotite gneiss has previously been interpreted as a paragneiss resulting from metamorphism of dominantly pelitic sediments and local interleaved volcanic beds ( Silver, 1971 ; Frizzell and Powell, 1982 ), although sillimanite was not found to be a prominent constituent. Silver et al. (1963) and Silver...
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Journal Article
Journal: GSA Bulletin
Published: 06 April 2020
GSA Bulletin (2020) 132 (11-12): 2415–2431.
..., quartzite, amphibolite, and magmatic veins. The protoliths of paragneisses from the Maxianshan Group were reported to have formed at 940 ± 30 Ma ( Wan et al., 2003 ). The Phanerozoic cover contains early Paleozoic volcano-sedimentary series, late Paleozoic to Triassic shallow marine to continental sediments...
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Journal Article
Published: 03 March 2020
Journal of the Geological Society (2020) 177 (4): 738–751.
... partitioning in partially molten rock remain poorly understood. We use field and microstructural observations to unravel the evolution of a partial melt shear zone, Seiland Igneous Province, northern Norway. The Øksfjord shear zone (ØSZ) is one of several paragneiss shear zones present within gabbros...
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Journal Article
Published: 01 February 2020
Italian Journal of Geosciences (2020) 139 (1): 131–148.
...Gabriele Cruciani; Marcello Franceschelli; Valeria Caironi; Giovanni Musumeci ABSTRACT Chemical analyses of garnet-bearing metasediments and EMP and U/Pb analyses of detrital zircons of the Lula paragneisses in the Axial Zone of the Variscan belt (NE Sardinia) give significant contribution...
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Journal Article