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orthogneiss

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Journal Article
Published: 01 April 2025
Russ. Geol. Geophys. (2025) 66 (4): 379–402.
... om111 63.589 159.155 Orthogneiss Upper Omolon 1989 10 1.17 – 16   om108-1 63.566 159.192 Orthogneiss Noddi 1944 18 0.8 – 6   om90 63.449 158.908 Leucogranite Anmandykan 424 2 0.04 0.85 6   om75-1 63.420 158.950 Leucogranite Anmandykan 433 3 1.0 0.33 9...
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Journal Article
Journal: GSA Bulletin
Published: 14 November 2024
GSA Bulletin (2025) 137 (3-4): 1649–1669.
... of the Sakarya Composite Terrane (SCT). It consists of para- and orthogneisses that host bands, lenses, boudins, and tectonic slices of amphibolites, and are altogether intruded by the Sarıcakaya Granitoid. The characterization and timing of the precursor magmatic events for the protoliths of this assemblage...
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Journal Article
Published: 08 November 2024
Journal of the Geological Society (2025) 182 (1): jgs2024-093.
... are visible in either unit, and the order of succession is unknown. Granitic orthogneisses and amphibolite intrusions were emplaced either prior to or during the earliest tectonic events ( Flinn 1994 , 2014 ). Lower age limits on deposition are provided by the ages of youngest detrital zircons, which are c...
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Journal Article
Published: 11 October 2024
Bulletin de la Société Géologique de France (2024) 195 (1): 20.
...-LP cycle ending with a first retrogression and a subsequent HP eclogite-facies metamorphism similar to that of the neighbouring eclogites. Some paragneisses and orthogneisses are only slightly deformed and retrogressed, showing the structure of nebulitic migmatite or metagranite, respectively; both...
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Journal Article
Published: 01 October 2024
Italian Journal of Geosciences (2024) 143 (3): 426–454.
... ) and on the orthogneiss from the La Reale area ( Franceschelli et al., 1989 ; Di Pisa et al., 1993 ). Amphibolite bodies are embedded within migmatite of the HGMC, P-T estimates on such rocks from the Punta Scorno area ( Fig. 3a ) revealed an early granulitic stage (minimum P=0.7–0.8 GPa and T=720–740 °C; Di Pisa et al...
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Journal Article
Published: 04 September 2024
Scottish Journal of Geology (2024) 60 (2): sjg2024-005.
...J. Stephen Daly; Michael J. Flowerdew; Martin J. Whitehouse; Eszter Badenszki A geochronological and isotopic study grounded by field observations is presented on the southernmost Lewisian orthogneisses of Iona, SW Scotland. Syenitic orthogneisses in western Iona and granodioritic orthogneisses...
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Journal Article
Journal: GSA Bulletin
Published: 03 July 2024
GSA Bulletin (2025) 137 (1-2): 241–258.
... Ga, with minor ages of 1000–900 Ma and 2000–1500 Ma and only 1–2 grains 3.0–2.5 Ga, indicating maximum depositional ages of 1000–900 Ma. A new U-Pb zircon age for an orthogneiss lens in marble is 661 ± 3 Ma like others previously dated in the Nome Complex. Orthogneiss ages provide an upper age limit...
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Journal Article
Published: 20 June 2024
Bulletin de la Société Géologique de France (2024) 195 (1): 10.
... of northern Brittany. It is established that granitic, porphyritic rocks crystallized at the end of the Rhyacian (Paleoproterozoic), 2038 ± 12 Ma ago, before being transformed into orthogneisses at a late Neoproterozoic (Ediacaran) age of 621 ± 2 Ma, which is a minimum age, given the retrograde alteration...
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Journal Article
Journal: GSA Bulletin
Published: 07 June 2024
GSA Bulletin (2024) 136 (11-12): 5231–5248.
..., including the accretion of discrete terranes. The oldest rocks, found in the Garzon Massif, are high-grade metamorphic rocks with contrasting Proterozoic protolith crystallization ages. Whereas the SW part of the massif formed during the Putumayo Orogeny (ca. 1.2–0.9 Ga), we report orthogneisses for the NE...
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Series: Geological Society, London, Special Publications
Published: 22 April 2024
DOI: 10.1144/SP542-2022-359
EISBN: 9781786206398
... Rheic Ocean suture. Meta-intrusive rocks from c. 620 and 625 Ma contain a mylonitic fabric and intrude foliated mafic metavolcanic rocks. At c. 305 Ma, granulite facies orthogneisses were thrust over amphibolite facies meta-igneous rocks in the transpressive Tinker Creek Nappe. The overturned limb...
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Journal Article
Published: 05 February 2024
Journal of the Geological Society (2024) 181 (2): jgs2023-171.
... outcrops in terms of exposure and preservation were identified on the western border of the massif, mainly related to the hanging wall of the Alicura and Manzano faults ( Fig. 2 ). The basement here is represented by schists, migmatites (metatexites and minor diatexites), orthogneisses, granitoids...
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Journal Article
Published: 01 February 2024
American Mineralogist (2024) 109 (2): 286–301.
... microblocks consist of orthogneiss, amphibolite, and lenses of BIF-bearing metavolcanic and metasedimentary rocks ( Zhai et al. 2015 ; Tang and Santosh 2018 ; Duan et al. 2021 ). The BIF-hosted Fe deposits in the Eastern Zone are located at the Jianping, northern Liaoning, eastern Hebei, and western...
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Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 19 January 2024
Lithosphere (2024) 2024 (1): lithosphere_2023_272.
... abundance and their poor quality, the boundaries between the lithologies are only approximate. Similarly, the different varieties of the lithodemic Haad Nai Phlao Complex (i.e., Haad Nai Phlao paragneiss [HNP], Haad Nai Phlao orthogneiss [HNP-cg], Haad Nai Phlao meta-andesite [HNP-a]; all formerly...
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Series: Geological Society, London, Special Publications
Published: 04 October 2023
DOI: 10.1144/SP531-2022-162
EISBN: 9781786209634
... photographs of the Betsiboka Suite: ( a ) granite showing large K-feldspar augen at the sampling location of DA13-003; ( b ) migmatitic orthogneiss at the sampling location of DA13-016; ( c ) charnockite at the sampling location of DA13-080; and ( d ) granite orthogneiss at the Betsiboka River Bridge...
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Journal Article
Published: 21 August 2023
Journal of the Geological Society (2023) 180 (5): jgs2022-092.
... and Cambrian–Ordovician metamorphism in the northern Swedish Caledonides. This work includes several lithologies of the Mårma terrane in the Seve Nappe Complex exposed in the Kebnekaise region. U–Pb zircon geochronology yielded crystallization ages of 835 ± 8 Ma for a mylonitic orthogneiss, 864 ± 3 Ma...
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Journal Article
Published: 04 August 2023
Geological Magazine (2023) 160 (7): 1376–1394.
... pressure (∼775–850 °C and 0.5–0.6 GPa; Rolland et al. 2001 ; Rolland et al. 2006 b) event is also recorded in domal culminations (Dassu and Askole) in the area (Searle, 1991 ). Monazite from sillimanite-bearing orthogneiss in the core of the Dassu dome are as young as ca. 5.4 Ma (Fraser et al. 2001...
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Journal Article
Published: 03 July 2023
Mineralogical Magazine (2023) 87 (5): 741–747.
... = □, Ca, Na and Fe 2+ ; M = Mg, Fe 2+ , Fe 3+ , Al and Mn; T = Si and P; Ø = O and OH; Z = □, OH and F). It was found in cavities of a leucogranitic orthogneiss at the Casette quarry, Montoso, Bagnolo Piemonte, Cuneo Province, Piedmont, Italy. Crystals of aluminotaipingite-(CeCa) are light pink to pink...
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Series: GSA Memoirs
Published: 23 January 2023
DOI: 10.1130/2022.1220(17)
EISBN: 9780813782201
... of dioritic to granitic orthogneisses occupy intermediate positions in Quebecia and in the west. The inboard granites are consistently old in all segments (1.5–1.45 Ga), but the preserved volcano-sedimentary belts are older in the east and in Quebecia (1.5–1.45 Ga) and younger in the west (1.39? and 1.36 Ga...
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Journal Article
Journal: Geology
Published: 11 October 2022
Geology (2022) 50 (12): 1387–1392.
... orthogneisses recrystallized at granulite-facies conditions (~800–900 °C and <10 kbar) during the Sveconorwegian orogeny at ca. 930 Ma ± 50 Ma ( Bingen et al., 2001 ). Subsequently, these rocks were partially overprinted at upper-amphibolite to eclogite-facies conditions during the Caledonian orogeny between...
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Series: GSA Special Papers
Published: 03 May 2022
DOI: 10.1130/2021.2555(07)
EISBN: 9780813795553
...-MS) coupled to a Photon Machines Analyte 193H, a 193 nm ArF excimer laser with a Helex 2-volume laser-ablation cell, following analytical procedures described in Sharman et al. (2013) . One sample of orthogneiss, which intruded into unit Єpm, as well as one additional sample and one duplicate...
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