The Granulite Belt of Lapland

Barbey, Pierre; Raith, M.

doi:10.1007/978-94-009-2055-2_7

Cited by 21 publications

(7 citation statements)

References 31 publications

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“…penetrative schistosity and shear band foliation of the belt were formed in the deep crust before and during the granulite grade metamorphism (Hormann ef al., 1980;Barbey and Raith, 1990), as is commonly the case in granulite terrains (Harley, 1989). Intrusion of enderbitic melts (1.93 Ga) (Meriliiinen, 1976;Sorjonen-Ward et al, 1994) was concomitant with metamorphism and deformation, as is shown by the mineral assemblages and explicitly by the concordant sheet-like geometry of the crystallized rock bodies (Figs 1 and 2a).…”

Section: Geological Evolutionmentioning

confidence: 75%

“…The belt offers a large section of deep crustal (6-9 kbar) rocks for examination of their geological and geophysical properties. It comprises a 40-90 km wide and 400 km long sequence of Palaeoproterozoic (2.0-1.9 Gal metasedimentary (khondalites) and metaigneous rocks (enderbites), which border to the NE and S to the Archaean Inari and Savukoski terranes, respectively, and are juxtaposed on its SW margin to the Palaeoproterozoic Central Lapland-Karasjok Schist Belt (Eskola, 1952;MerGinen, 1976;Honnann et al, 1980;Ga&l et al, 1989; Barbey and Raith, 1990;Sorjonen-Ward et al, 1994). Between the Central Lap land-Karasjok Schist Belt and the LGB there is a narrow belt of strongly reworked mafic volcanics and granitic gneisses intruded into them collectively called Tanaelv Belt (Marker, 1990(Marker, ,1991.…”

Section: Tectonic Setting Of the Lapland Granulite Beltmentioning

confidence: 99%

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Field, petrophysical and carbon isotope studies on the Lapland Granulite Belt: implications for deep continental crust

et al. 1996

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The Palaeoproterozoic Lapland Granulite Belt is a seismically reflective and electrically conductive sequence of deep crustal (6–9 kbar) rocks in the northern Fennoscandian Shield. It is composed of garnet‐sillimanite gneisses (khondalites) and pyroxene granulites (enderbites) which in certain thrust sheets form about 500 m thick interlayers. The structure was formed by the intrusion of intermediate to basic magmas into turbiditic sedimentary rocks under granulite facies metamorphism accompanied by shearing of the deep crust about 1.93–1.90 Gyr ago (Gal. Granulites were upthrust 1.90–1.87 Ga and the belt was divided by crustal scale duplexing into four structural units whose layered structure was preserved. The thrust structures are recognized by the repetition of lithological ensembles and by discordant structural patterns well distinguishable in airborne magnetic and electromagnetic data. Thrusting gave rise to clockwise pressure‐temperature evolution of the belt. However, some basic rocks possibly record an isobaric cooling path. The low bulk resistivity of the belt (200–1000 Ωm) is caused by interconnected graphite and subordinate sulphides in shear zones. On the basis of carbon isotope ratios this graphite is derived mostly from sedimentary organic carbon. The seismic reflectivity of the belt may be caused by velocity and density differences between pyroxene granulites and khondalites, as well as by shear zones.

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Section: Geological Evolutionmentioning

confidence: 75%

Section: Tectonic Setting Of the Lapland Granulite Beltmentioning

confidence: 99%

Field, petrophysical and carbon isotope studies on the Lapland Granulite Belt: implications for deep continental crust

et al. 1996

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Section: Introductionmentioning

confidence: 99%

“…However, different conclusions have been reached in different regions. For example, the Archaean complexes in the central Limpopo Belt (Droop, 1989) and early Proterozoic granulite belt of Lapland (Barbey & Raith, 1988) are characterized by post-peak isothermal decompression, whereas the Napier Complex of Enderby Land (Harley, 1985) and the south-east Highland Series of Sri Lanka (Schenk e l af., 1988) show isobaric cooling P-T paths before tectonic uplift. In the Jining district of south-east Inner Mongolia, China, Archaean khondalites and granulites are widespread (Figs 1 & 2).…”

Section: Introductionmentioning

confidence: 99%

P–T–t paths and tectonic history of an early Precambrian granulite facies terrane, Jining district, south‐east Inner Mongolia, China

Lu¹,

Shiqin²

1993

Journal Metamorphic Geology

107

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The widespread khondalite series of south-east Inner Mongolia consists largely of biotite-sillimanitegarnet gneiss and quartzo-feldspathic gneiss with some marble and mafic granulite layers. It has experienced two metamorphic events at c. 2500 and 1900-2000 Ma.A pre-peak stage of the first metamorphism at T = 600-700" C and P > 6-7 kbar is recognized by the relict amphibolite facies assemblage Ky-Grt-Bt-PI-Qtz and 'protected' inclusions of biotite, hornblende, sodic plagioclase and quartz in garnet or orthopyroxene. The peak stage, with T = c. 800 f 50" C and P 8-10 kbar, is characterized by the widespread granulite facies assemblages Sil-Grt-Bt-Kfs-PI-Qtz in gneiss and Opx-Cpx-PI f Hbl f Grt in granulite. The P-T-t path suggests that the supracrustal sequence was buried in the lower &st by tectonic thickening during Dl-D2. The beginning of the second metamorphism is characterized by further temperature rise to 700°C or more at lower pressure. This stage is manifested by the appearance of cordierite after garnet, fibrolite (Si12) after biotite in gneiss and transformation of Hbll into Opx2 and Cpx2 in granulite. Coronas of symplectitic Opx2 + PI2 surrounding Grtl and Cpxl in mafic granulite are interpreted as products of near-isothermal decompression. The P-T-t path may be related tectonically to waning extension of the crust by the end of the early Proterozoic.

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“…De nombreuses études pétro-structurales, géochronologiques, géochimiques et géophysiques ont montré que le Paléoprotérozoïque est une période charnière dans l'évolution de la croûte terrestre (Barbey et Raith, 1990 ;Lucas et al, 1994 ;Hajnal et al, 1995 ;Vidal et al, 1996 ;Pons et al, 1995 ;Vidal et al, 1996 ;Mortaji et al, 2000). Les caractères archaïques y sont bien marqués, mais de plus en plus d'études révèleraient l'existence d'autres caractères se rapprochant de ceux des chaînes modernes.…”

Section: Introductionunclassified

Petrographie Des Volcanites Et Plutonites De La Partie Sud Du Sillon Volcano-Sedimentaire De Toumodi-Fetekro (Cote D’ivoire)

Inza

Nicaise

Chérubin

et al. 2017

ESJ

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The southern part of Toumodi-Fètêkro greenstone belt is located in the Center -Southeast of Ivory Coast. Petrographic study of volcanic and plutonic rocks shows three units. The first unit is composed of basaltic to rhyolitic lavas which imply effusive character. Then we have volcanosedimentary unit composed of pyroclastic formations (lapilli tuff, breccia, ash deposit and ignimbrites) and the pillow-lavas. Indeed, the presence of this last shows clearly that an explosive volcanism and a submarine effusive volcanism have occurred during during the setting of Toumodi-Fètêkro belt. Plutonic unit is constituted of gabbroic to granitic rocks. Sericite, chlorite, epidote observed in these rocks are consistent with the impacts of greenschist facies metamorphism. The rocks of the southern part of the Toumodi-Fètêkro greenstone belt are formed in a subduction context rather than in oceanic plateaus context because of the old inheritance, sometimes of Archean age, found somewhere in theBirimiandomain. The lithologies of the southern part of Toumodi-Fètêkro meet elsewhere in the other Birimian greenstone belts. Also, these lithologies are affected by a hydrothermal alteration due to the abundant veins of quartz, carbonates, sericite, chlorite, epidote, sulphides and oxides. However, volcanic show in some places amphibolit facies metamorphism. Keywords

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The Granulite Belt of Lapland

Cited by 21 publications

References 31 publications

Field, petrophysical and carbon isotope studies on the Lapland Granulite Belt: implications for deep continental crust

Field, petrophysical and carbon isotope studies on the Lapland Granulite Belt: implications for deep continental crust

P–T–t paths and tectonic history of an early Precambrian granulite facies terrane, Jining district, south‐east Inner Mongolia, China

Petrographie Des Volcanites Et Plutonites De La Partie Sud Du Sillon Volcano-Sedimentaire De Toumodi-Fetekro (Cote D’ivoire)

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