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paragneiss

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Journal Article
Journal: GSA Bulletin
Published: 07 October 2020
GSA Bulletin (2020)
..., 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...
Journal Article
Journal: GSA Bulletin
Published: 06 April 2020
GSA Bulletin (2020) 132 (11-12): 2415–2431.
... and intercalated lenses or layers of marble, 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...
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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
Journal: Economic Geology
Published: 01 December 2019
Economic Geology (2019) 114 (8): 1569–1598.
.... The majority of the deposits are hosted within sodically altered Lyon Mountain granite gneiss, although some deposits occur within paragneiss, gabbro, anorthosite, or potassically altered Lyon Mountain granite gneiss. The IOA deposits and the waste and/or tailings piles associated with them have potential...
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Journal Article
Published: 22 November 2019
Bulletin de la Société Géologique de France (2019) 190 (1): 12.
..., paragneisses, and amphibolites that include pre-anatectic relics of eclogites, high-pressure mafic granulites, ultramafites and calc-silicates ( Faure-Muret, 1955 ; Malaroda et al. , 1970 ; Blasi, 1971 ; Bortolami et al. , 1974 ; Bogdanoff and Ploquin, 1980 ; Bogdanoff, 1986 ; Latouche and Bogdanoff...
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Journal Article
Journal: Geology
Published: 22 May 2019
Geology (2019) 47 (8): 715–718.
... UHP minerals. The “gneiss-eclogite unit” of the Saxonian Erzgebirge, located in the northwestern Bohemian Massif (Germany), was subjected to ultrahigh-pressure (UHP) metamorphic conditions during the Variscan orogeny. This unit is predominantly composed of ortho- and paragneisses with numerous...
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Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 16 April 2019
Lithosphere (2019) 11 (4): 465–487.
...-to-north shear-sense, extending as much as ∼1 km below and ∼2 km above the GH-Chekha Formation contact. The GH section in northwestern Bhutan consists of ∼8 km of migmatitic, garnet- and sillimanite-bearing paragneiss, with interlayered schist, quartzite, and orthogneiss ( Gansser, 1983 ; Kellett et...
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Journal Article
Published: 07 February 2019
Canadian Journal of Earth Sciences (2019) 56 (8): 829–847.
... populations with ages ranging from 3.2 to ca. 1 Ga. Paragneiss units from the Kellys Mountain area contain Meso- to Neoproterozoic detrital zircons, in which the youngest grains indicate that the maximum depositional age is <600 Ma. The detrital zircon populations of rocks from both areas are consistent...
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Series: Geological Society, London, Special Publications
Published: 01 January 2019
DOI: 10.1144/SP474.11
EISBN: 9781786204202
..., we report the age of metamorphism of high-pressure (HP) granulite-facies paragneisses from the Namche Barwa Complex (NBC). These paragneisses consist of variable proportions of garnet, biotite, plagioclase, K-feldspar, quartz, rutile and ilmenite. Using phase equilibrium modelling of garnet growth...
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Journal Article
Published: 01 January 2019
American Mineralogist (2019) 104 (1): 17–30.
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Journal Article
Published: 27 December 2018
Scottish Journal of Geology (2019) 55 (1): 21–34.
... and myrmekite growth in feldspars. These textures are locally overprinted by lower temperature textures such as subgrain formation in quartz and core mantle textures in feldspars. Partly migmatized paragneisses occur as xenoliths in the granites. They are increasingly common towards the southwestern part...
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Series: GSA Field Guides
Published: 29 March 2018
DOI: 10.1130/2018.0050(08)
EISBN: 9780813756509
...—Grenville basement; GSF—Great Smoky fault; GSG—Great Smoky Group; MB—Murphy belt; SG—Snowbird Group; WBR—Western Blue Ridge; WCG—Walden Creek Group. States: GA—Georgia; NC—North Carolina; TN—Tennessee. Figure 10. Zircon U-Pb geochronology for migmatitic paragneisses from the Clyde 7.5 min...
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Journal Article
Journal: Geosphere
Published: 05 February 2018
Geosphere (2018) 14 (2): 835–860.
... history of this and related Paleozoic arc terranes of the western North American Cordillera. Mapping shows that the oldest YAC rocks consist of quartzofeldspathic paragneiss (meta-arkose) and quartzose calc-silicate paragneiss (metacalcareous siltstone) in gradational contact. Paragneisses are cut by syn...
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Journal Article
Published: 01 December 2017
Mineralogical Magazine (2017) 81 (6): 1503–1521.
...Maw Maw Win; M. Enami; T. Kato; Ye Kyaw Thu Abstract Rutile grains occur extensively in host phases of biotite and quartz-feldspar aggregate in high-temperature paragneisses of the Mogok metamorphic belt of Myanmar. They occur as an isolated phase and sometimes show intergrowth texture...
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Series: GSA Memoirs, GSA Memoirs
Published: 11 September 2017
DOI: 10.1130/2017.1213(10)
EISBN: 9780813782133
.... Additionally, there are limited samples in the Georgia Blue Ridge and Inner Piedmont and no samples from Alabama included in this study ( Fig. 3 ). In general, 5 to 10 kg rock samples were collected from various orthogneiss and paragneiss units in the Blue Ridge and Inner Piedmont. Careful sample selection...
Journal Article
Journal: Geosphere
Published: 01 June 2017
Geosphere (2017) 13 (3): 681–698.
... with paragneiss containing quartzite and calc-silicate rock. Structurally below the orthogneiss, some quartzites have multiple concordant populations of detrital-zircon grains as young as ca. 1700 Ma, while others have no zircon grains younger than ca. 2500 Ma. Structurally above the Archean gneiss...
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Journal Article
Published: 07 March 2017
Geological Magazine (2018) 155 (6): 1263–1276.
...–0.68), and have flat heavy rare earth elements (HREE) patterns. The high contents of transition elements (e.g. Cr, Ni, Sc, V) and moderately radiogenic Nd isotopic compositions suggest that the paragneisses might be those of first-cycle erosion products of predominantly mafic rocks mixing with small...
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Journal Article
Published: 01 November 2016
European Journal of Mineralogy (2016) 28 (4): 765–775.
... crystals occur in a vuggy, 3 cm thick hydrothermal pyrite vein, penetrating a migmatized paragneiss near the contact with two-mica granite of the Eisgarn type. Separated crystals (43 altogether) were studied using a four-circle X-ray diffractometer with a CCD area detector. From 217 frames per user-defined...
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Journal Article
Journal: GSA Bulletin
Published: 01 November 2016
GSA Bulletin (2016) 128 (11-12): 1571–1592.
... of exhumation of the Greater Himalayan Sequence mainly driven by the coupled activity of Main Central thrust and South Tibetan detachment between ca. 23 and 17 Ma. TABLE 1. REPRESENTATIVE ELECTRON MICROPROBE ANALYSES (IN WT%) OF MINERALS IN THE PARAGNEISS SAMPLE KL-19 TABLE 2. REPRESENTATIVE...
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