Mesoarchean to Paleoproterozoic Crustal Evolution of the Belomorian Province, Fennoscandian Shield, and the Tectonic Setting of Eclogites

2021 ◽  
Vol 62 (5) ◽  
pp. 525-546
Author(s):  
A.I. Slabunov ◽  
V.V. Balagansky ◽  
A.A. Shchipansky
Keyword(s):  
Tectonic Setting ◽  
Granulite Facies ◽  
Fennoscandian Shield ◽  
Western Coast ◽  
High Grade ◽  
Structural Element ◽  
Metamorphic Overprint ◽  
History Of ◽  
Characteristic Features ◽  
Collisional Orogeny

Abstract —The Belomorian Province (BP) of the Fennoscandian Shield is a high-grade belt composed of Meso- to Neoarchean tonalite– trondhjemite–granodiorite (TTG) gneisses with subordinate supracrustal complexes. The Belomorian crust is underlined by a thick mantle keel, a structural element typical of Archean cratons. Belomorian rocks were metamorphosed under conditions of mainly high-pressure amphibolite to granulite facies in both Archean and Paleoproterozoic times. The TTG gneisses contain numerous blocks of almost completely retrogressed eclogite (eclogite-1). This paragenetic association of eclogite-1 and gneisses can be classified as an Archean eclogite–TTG gneiss mélange, a component of the Belomorian continental crust produced by subductional, accretionary, and collisional processes of the Belomorian collisional orogeny 2.9–2.66 Ga. The Paleoproterozoic history of the BP comprises of two prominent tectonic periods: (i) early Paleoproterozoic (~2.5–2.4 Ga), related to a superplume, and (ii) late Paleoproterozoic (2.0–1.85 Ga), resulted from crustal reworking during the Lapland–Kola collisional orogeny that produced strong penetrative metamorphic and local deformational overprint. The Paleoproterozoic highest-grade metamorphic overprint is represented by patches of eclogites (eclogite-2) in Paleoproterozoic mafic dikes and eclogite-1. Field relations between eclogite-1 and eclogite-2 are described in the Gridino area of the western coast of the White Sea. So, the BP is a high-grade polymetamorphic belt formed by a superposition of the Neoarchean Belomorian and Paleoproterozoic Lapland–Kola orogenies, whose characteristic features are eclogites produced by subduction and collision.

The Pikwitonei Granulite Domain, Manitoba: a giant Neoarchean high-grade terrane in the northwest Superior ProvinceThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.N. Machado, T.E. Krogh, and W. Weber are deceased.

2011 ◽  
Vol 48 (2) ◽  
pp. 205-245 ◽  
Author(s):  
L. M. Heaman ◽  
Ch. O. Böhm ◽  
N. Machado ◽  
T. E. Krogh ◽  
W. Weber ◽  
...  
Keyword(s):  
Granulite Facies ◽  
Superior Province ◽  
High Grade ◽  
Metamorphic Zircon ◽  
Special Issue ◽  
Metamorphic History ◽  
Zircon Growth ◽  
The World ◽  
Northwestern Margin ◽  
History Of

The Pikwitonei Granulite Domain located at the northwestern margin of the Superior Province is one of the largest Neoarchean high-grade terranes in the world, with well-preserved granulite metamorphic assemblages preserved in a variety of lithologies, including enderbite, opdalite, charnockite, and mafic granulite. U–Pb geochronology has been attempted to unravel the protolith ages and metamorphic history of numerous lithologies at three main localities; Natawahunan Lake, Sipiwesk Lake, and Cauchon Lake. The U–Pb age results indicate that some of the layered enderbite gneisses are Mesoarchean (3.4–3.0 Ga) and the more massive enderbites are Neoarchean. The high-grade metamorphic history of the Pikwitonei Granulite Domain is complex and multistage with at least four episodes of metamorphic zircon growth identified: (1) 2716.1 ± 3.8 Ma, (2) 2694.6 ± 0.6 Ma, (3) 2679.6 ± 0.9 Ma, and (4) 2642.5 ± 0.9 Ma. Metamorphic zircon growth during episodes 2 and 3 are interpreted to be regional in extent, corresponding to M1 amphibolite- and M2 granulite-facies events, respectively, consistent with previous field observations. The youngest metamorphic episode at 2642.5 Ma is only recognized at southern Cauchon Lake, where it coincides with granite melt production and possible development of a major northeast-trending deformation zone. The timing and multistage metamorphic history recorded in the Pikwitonei Granulite Domain is similar to most Superior Province high-grade terranes and marks a fundamental break in Archean crustal evolution worldwide at the termination of prolific global Neoarchean greenstone belt formation.

scholarly journals The Archaean gneiss complex of northern Labrador A review of current results, ideas and problems

1991 ◽  
Vol 39 ◽  
pp. 153-166
Author(s):  
D. Bridgwater ◽  
L. Schiøtte
Keyword(s):  
Major Part ◽  
Granulite Facies ◽  
High Grade ◽  
Late Archaean ◽  
West Greenland ◽  
Metamorphic History ◽  
Gneiss Complex ◽  
History Of ◽  
Augen Gneiss ◽  
Dominant Phase

1. The early Archaean rocks in northern Labrador can be subdivided into the ea. 3.78 Ga Nulliak supracrus­tal association, the migmatitic Uivak I gneisses, the dominant phase of which was emplaced at ea. 3.73 Ga, and the Uivak II augen gneiss. Inherited low-U rounded inclusions within igneous zircons in the Uivak I gneisses have ages between 3.73 and 3.86 Ga and are more likely to have been derived from a pre-existing high-grade metamorphic gneiss complex than from the Nulliak association. In the early Archaean there were probably several rapid cycles of sedimentary deposition and volcanism followed by emplacement of major plutons. Mid Archaean gneisses are more abundant in northern Labrador than previously realised. The late Archaean metamorphic history of these gneisses is different from the history of the early Archaean gneisses. Whereas an important part of the mid Archaean suite was emplaced in granulite facies and retrogressed at the time of granitoid veining at ea. 2.99 Ga, the major part of the early Archaean rocks were reworked under granulite facies conditions in a sequence of closely spaced events between 2. 7 and 2.8 Ga. The two groups of gneisses had different metamorphic histories until ea. 2.7 Ga, but late and post-tectonic granites of 2.5- 2. 7 Ga age cut across both. It is suggested that the terrane model in southern West Greenland can be extended to Labrador and that tectonic intercalation of early and mid Archaean gneisses took place around 2.7 Ga. Correlation between the Maggo gneisses around Hopedale, mid Archaean gneisses in northernmost Labrador and gneisses from the Akia terrane in West Greenland is suggested. Like the Malene supracrustals in West Greenland the Upernavik supracrustals in Labrador are composite associations, the youngest of which are thought to have been deposited around 2. 7 Ga.

Metamorphic evolution and geochronology of gneisses from the Wanni Complex, Sri Lanka

2020 ◽  
Author(s):  
Marcel Masten ◽  
Christoph A. Hauzenberger ◽  
Nikolaus Lechner ◽  
Daniela Gallhofer ◽  
G.W.A. Rohan Fernando
Keyword(s):  
Earth Sciences ◽  
Sri Lanka ◽  
Granulite Facies ◽  
Northwestern Part ◽  
Southwestern Part ◽  
Metamorphic Overprint ◽  
Icp Ms ◽  
Wide Range ◽  
History Of ◽  
Isotopic Model

<p>The Wanni Complex is found in the northwestern part of Sri Lanka. The boundary to the Highland complex occurring to the south is partly ill defined. Differences in isotopic model ages were used to seperate both units (Kitano et al. 2018; Milisenda et al. 1994). While the Highland Complex has gained a lot of attention due to the UHT metamorphic overprint (up to 1150°C and 8-12kbar)(Sajeev and Osanai 2004) detailed petrological and geochronological work in the Wanni Complex is missing. Only a few studies focus on the border area between the Wanni Complex and the Highland Complex (Kitano et al. 2018; Wanniarachchi and Akasaka 2016).</p><p>Large areas of the Wanni Complex are covered by biotite gneisses, mostly migmatic, partly with occurrences of arrested charnockites or displaying potassium metasomatism (Cooray 1994; Kröner et al. 2003). However, charnockitic gneisses, garnet bearing gneisses and in the southwestern part cordierite bearing gneisses and metapelites occur which can be used for obtaining the PTt history of this complex. PT conditions of the Wanni Complex obtained from garnet bearing rocks place the metamorphic overprint clearly into the granulite facies and partly into the UHT field. Compared to the Highland Complex, temperatures are somewhat lower at 800-1000°C at 7-9kbar.</p><p>LA-ICP-MS U/Pb dating was performed on zircons from different locations of the Wanni Complex and shows igneous protolith ages of 855-963Ma. The ages were obtained from felsic hornblende-biotite gneisses and charnockitic gneisses. The wide range of ages could be a result of resetting shortly after magmatic crystallisation. CL images of some zircons show dark zones separated from oscillatory zoned cores by thin bright fronts. Taken together with core/rim dating of these zircons, this could be a sign of transgressive recrystallization (Hoskin and Black 2000).</p><p> </p><p> </p><p>Cooray, P.G. 1994. Precambrian Research 66(1–4):3–18.</p><p>Hoskin, P.W. and Black L.P. 2000. Journal of Metamorphic Geology 18:423–39.</p><p>Kitano, I., Osanai, Y., Nakano, N., Adachi, T. and Fitzsimons, I.C.W. 2018. Journal of Asian Earth Sciences 156:122–44.</p><p>Kröner, A., Kehelpannala, K.V.W. and Hegner, E. 2003. Journal of Asian Earth Sciences 22(3):279–300.</p><p>Milisenda, C.C., Liew, T.C., Hofmann, A.W. and Köhler, H. 1994. Precambrian Research 66:95–110.</p><p>Sajeev, K. and Osanai, Y. 2004. Journal of Petrology 45(9):1821–44.</p><p>Wanniarachchi, D.N.S. and Akasaka, M. 2016. Journal of Mineralogical and Petrological Sciences 111(5):351–62.</p>

Petrological evolution in the roof of the high-grade metamorphic Central Zone of the Limpopo Belt, South Africa

2005 ◽  
Vol 142 (3) ◽  
pp. 229-240 ◽  
Author(s):  
ARMIN ZEH ◽  
REINER KLEMD ◽  
JAY M. BARTON
Keyword(s):  
South Africa ◽  
Temperature Increase ◽  
Central Zone ◽  
Granulite Facies ◽  
High Grade ◽  
Metamorphic Overprint ◽  
Granulite Facies Metamorphism ◽  
Facies Metamorphism ◽  
Zonation Patterns ◽  
Limpopo Belt

In this study we present new petrological results from the Endora Klippe in the Central Zone of the Limpopo Belt, which may result from horizontal tectonics during the Proterozoic at c. 2.0Ga. Microstructures, assemblages and garnet zonation patterns observed in metapelitic rocks provide evidence that the Endora Klippe rocks underwent a contemporaneous pressure–temperature increase from c. 600°C/5kbar to 650°C/6.5kbar. This is inferred by the use of conventional geothermobarometry and interpretations based on quantitative phase diagrams in the system MnO–(TiO2)–(CaO)–(Na2O)–K2O–MgO–Al2O3–SiO2–H2O. Thus, the petrological results indicate that this part of the Central Zone only underwent a medium-grade metamorphic overprint during a single orogenic event and was never affected by granulite-facies metamorphism, as reported from other parts of the Limpopo Belt. The inferred P–T path, in combination with previous structural and petrological results, leads to the conclusion that the area surrounding the Endora Klippe forms the roof zone of the c. 2.0Ga old granulite-facies rocks forming wide parts of the Limpopo Central Zone.

Thermobarometry and geochronology of the Uvauk complex, a polymetamorphic Neoarchean and Paleoproterozoic segment of the Snowbird tectonic zone, Nunavut, Canada

2007 ◽  
Vol 44 (2) ◽  
pp. 245-266 ◽  
Author(s):  
A J Mills ◽  
R G Berman ◽  
W J Davis ◽  
S Tella ◽  
S Carr ◽  
...  
Keyword(s):  
High Pressure ◽  
Shear Zones ◽  
Granulite Facies ◽  
Crustal Thickening ◽  
High Grade ◽  
Retrograde Metamorphism ◽  
Tectonic Zone ◽  
History Of ◽  
Thermal Overprint ◽  
Temperature Time

The Uvauk complex is an ultramylonite-bounded, granulite-facies suite of anorthosite–gabbro that forms part of the Chesterfield Inlet segment of the Snowbird tectonic zone. Following initial anorthosite–gabbro magmatism at ca. 2.71 Ga and a cryptic 2.62–2.60 Ga event marked by zircon and monazite growth, the Uvauk complex experienced two high-grade tectonometamorphic events at 2.56–2.50 and 1.91–1.90 Ga. Similar to the 2.56–2.50 Ga development of other shear zones in the region, the upper-amphibolite-facies to granulite-facies, moderately high-pressure (8.4–11.0 kbar and 705–760 °C) (1 kbar = 100 MPA) M1 event is interpreted to have involved the structural emplacement of ca. 2.71 Ga Uvauk complex rocks on ca. 2.68 Ga tonalitic rocks to the south. Granulite-facies, high-pressure (11.2–14.7 kbar and 695–865 °C) M2 metamorphism, gabbroic magmatism, and mylonite development within the complex at ca. 1.9 Ga culminated with ~3.5 kbar decompression at high temperature. Clockwise pressure–temperature–time (P–T–t) paths reflect crustal thickening, thought to be related to the early accretionary history of the Trans-Hudson Orogen. A thermal overprint at ca. 1.85–1.75 Ga resulted in retrograde metamorphism (5.8–6.0 kbar and 625–695 °C) associated with post-tectonic granitoid plutonism.

Mesyatseslovs memory of the Russian Orthodox Church

2020 ◽  
pp. 160-198
Author(s):  
Макарий Веретенников
Keyword(s):  
Russian Orthodox ◽  
Orthodox Church ◽  
Russian Orthodox Church ◽  
Analysis And Synthesis ◽  
Liturgical Texts ◽  
History Of ◽  
Complete Form ◽  
Characteristic Features ◽  
Heaven And Earth ◽  
The Church

Статья посвящена содержанию, общим принципам построения и характерным особенностям календаря, или месяцеслова, Русской Православной Церкви. Автор использует методы анализа и синтеза. В итоге делаются нижеследующие обобщения. Месяцеслов был принесён на Русь из Византии в достаточно завершённом виде, однако в процессе исторического развития он дополнился особенными русскими праздниками. Календарь-месяцеслов - это грандиозный собор святых, подвизавшихся в разных местах на протяжении веков, единение Церкви Небесной и земной, история святости и история нашей Церкви. Месяцесловным памятям посвящены составленные гимнографами богослужебные тексты, которые поются и читаются в храмах. Традиционно почитается день кончины угодников Божиих, память открытия мощей святых, перенесения их святых мощей или же день канонизации угодников Божиих, реже - день их рождения. Фенологические наблюдения русского народа связаны с повседневной деятельностью и увязаны с месяцесловом, что свидетельствует о его проникновении в повседневную жизнь русского человека. The article is devoted to the content, General principles of construction and characteristic features of the calendar, or mesyatseslov, of the Russian Orthodox Church. The author uses methods of analysis and synthesis. As a result, the following generalizations are made. The mesyatseslov was brought to Russia from Byzantium in a fairly complete form, but in the course of historical development it was supplemented with special Russian holidays. The calendar-mesyatseslov is a grandiose council of saints who have labored in different places over the centuries, the unity of the Church of Heaven and earth, the history of holiness and the history of our Church. Liturgical texts composed by hymnographers, which are sung and read in churches, are dedicated to the mesyatseslovs memory. Traditionally, the day of the death of saints, the memory of the discovery of the relics of saints, the transfer of their Holy relics, or the day of the canonization of saints, less often - the day of their birth are honored. Russian people’s phenological observations are related to their daily activities and are linked to mesyatseslov, which indicates its penetration into the daily life of the Russian people.

scholarly journals Identification of a Novel Missense KRT12 Mutation in a Vietnamese Family with Meesmann Corneal Dystrophy

2020 ◽  
Vol 11 (1) ◽  
pp. 120-126
Author(s):  
Pham Ngoc Dong ◽  
Le Xuan Cung ◽  
Tran Khanh Sam ◽  
Do Thi Thuy Hang ◽  
Doug D. Chung ◽  
...  
Keyword(s):  
Sanger Sequencing ◽  
Novel Mutation ◽  
Family Members ◽  
Corneal Dystrophy ◽  
Slit Lamp ◽  
Slit Lamp Examination ◽  
Corneal Epithelial ◽  
Epithelial Phenotype ◽  
History Of ◽  
Characteristic Features

Meesmann epithelial corneal dystrophy (MECD) is a rare dominantly inherited disorder that is characterized by corneal epithelial microcysts and is associated with mutations in the keratin 3 (KRT3) and keratin 12 (KRT12) genes. In this study, we report a novel mutation in the KRT12 gene in a Vietnamese pedigree with MECD. Slit-lamp examination was performed on each of the 7 recruited members of a Vietnamese family to identify characteristic features of MECD. After informed consent was obtained from each individual, genomic DNA was isolated from saliva samples and screening of KRT3and KRT12 genes was performed by Sanger sequencing. The proband, a 31-year-old man, complained of a 1-year history of eye irritation and photophobia. Slit-lamp examination revealed intraepithelial microcysts involving only the corneal periphery in each eye with clear central corneas and no stromal or endothelial involvement. Three family members demonstrated similar intraepithelial microcysts, but with diffuse involvement, extended from limbus to limbus. Sanger sequencing of KRT3 (exon 7) and KRT12 (exons 1 and 6) in the proband revealed a novel heterozygous KRT12 variant (c.1273G>A [p.Glu425Lys]) that was present in the three affected family members but was absent in the three family members with clear corneas. This study is the first report of a Vietnamese family affected with MECD, associated with an atypical peripheral corneal epithelial phenotype in the proband and a novel mutation in KRT12.

A Yahgan for the killing: murder, memory and Charles Darwin

2011 ◽  
Vol 46 (3) ◽  
pp. 415-443 ◽  
Author(s):  
JOSEPH L. YANNIELLI
Keyword(s):  
South America ◽  
Charles Darwin ◽  
Historical Memory ◽  
Cross Cultural ◽  
Western Coast ◽  
Cultural Interaction ◽  
European Expansion ◽  
Multiple Contexts ◽  
History Of

AbstractIn March 1742, British naval officer John Byron witnessed a murder on the western coast of South America. Both Charles Darwin and Robert FitzRoy seized upon Byron's story a century later, and it continues to play an important role in Darwin scholarship today. This essay investigates the veracity of the murder, its appropriation by various authors, and its false association with the Yahgan people encountered during the second voyage of theBeagle(1831–1836). Darwin's use of the story is examined in multiple contexts, focusing on his relationship with the history of European expansion and cross-cultural interaction and related assumptions about slavery and race. The continuing fascination with Byron's story highlights the key role of historical memory in the development and interpretation of evolutionary theory.

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