References of "Liégeois, Jean-Paul"
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See detailDifferentiation of tholeiitic basalt to A-type granite in the Sept Iles layered intrusion, Canada
Namur, Olivier ULg; Charlier, Bernard; Toplis, Michael et al

in Journal of Petrology (2011)

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See detailAnorthosite formation by plagioclase flotation in ferrobasalt and implications for the lunar crust
Namur, Olivier ULg; Charlier, Bernard ULg; Pirard, Cassian et al

in Geochimica et Cosmochimica Acta (2011), 75

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See detailSveconorwegian (Grenvillian) Massif type anorthosites and related granitoids result from postcollisional remelting of a continental arc root
Vander Auwera, Jacqueline ULg; Bolle, Olivier ULg; Bingen, Bernard et al

in EOS : Transactions, American Geophysical Union (2009), 90(52), 11-02

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See detailPetrogenesis of the Kabanga-Musongati layered mafic-ultramafic intrusions in Burundi (Kibaran Belt): geochemical, Sr-Nd isotopic constraints and Cr-Ni behaviour
Duchesne, Jean-Clair ULg; Liégeois, Jean-Paul ULg; Deblond, André et al

in Journal of African Earth Sciences (2004), 39

A succession of mafic-ultramafic layered intrusions forms an alignment in the boundary zone between the Kibaran belt and the Tanzania craton. The intrusions represent a continuous series of cumulate rocks ... [more ▼]

A succession of mafic-ultramafic layered intrusions forms an alignment in the boundary zone between the Kibaran belt and the Tanzania craton. The intrusions represent a continuous series of cumulate rocks. For instance, in the Mukanda-Buhoro and Musongati (MBM) contiguous bodies, the series starts with dunite and passes to lherzolite, pyroxenite, norite, gabbronorite and anorthosite on top. Cumulate textures are conspicuous in all rock types and cryptic layering characterises cumulus mineral compositions, thus evidencing fractional crystallization as a major differentiation mechanism. The increase of Cr in the ultramafic members of the series indicates that chromite was not a liquidus mineral in dunite and lherzolite rocks, thus unable to form chromitite layers. The high Ni-content of dunite seems to preclude the existence of conjugate Ni-rich sulphide deposits. The 87Sr/86Sr initial ratio is relatively constant and averages 0.7087, with some values up to 0.712 due to local assimilation. Fine-grained rocks from the MBM area are isotopically (Nd and Sr) similar to the MBM cumulates. Modelling their crystallization produces cumulus mineral compositions similar to those in the Musongati ultramafic rocks, which suggests a broadly picritic parental magma. On the other hand, fine-grained rocks from the Nyabikere area are not related to the Nyabikere cumulates. Nd and Sr isotope ratios show that the MBM magmatism is related to an enriched source, possibly an old subcontinental lithospheric mantle. The Nyabikere dykes, as well as the Waga dykes, come from a depleted mantle source, as do the A-type granitoids occurring in the same boundary zone. Several lines of evidence point to two types of parental magmas, a picritic magma, and a more evolved magma, broadly similar to the Bushveld Main Zone magma. [less ▲]

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See detailDerivation of the 1.0-0.9 Ga ferro-potassic A-type granitoids of southern Norway by extreme differentiation from basic magmas
Vander Auwera, Jacqueline ULg; Bogaerts, Michel; Liégeois, Jean-Paul ULg et al

in Precambrian Research (2003), 124(2-4), 107-148

Major and trace elements, Sr and Nd isotopic data as well as mineral compositions are presented for a selection of the 1.0 - 0.9 ferro-potassic A-type granitoids (Bessefjellet, Rustfjellet ... [more ▼]

Major and trace elements, Sr and Nd isotopic data as well as mineral compositions are presented for a selection of the 1.0 - 0.9 ferro-potassic A-type granitoids (Bessefjellet, Rustfjellet, Verhuskjerringi, Valle, Holum, Svöfjell, Handeland-Tveit, Åseral, Lyngdal gabbronorites) that occur close to the Mandal-Ustaoset Line of southern Norway. These hornblende biotite granitoids (HBG) define an extensive differentiation trend ranging from gabbronorites (50 wt % SiO2) to granites (77 wt % SiO2). This trend is interpreted as resulting from extreme fractional crystallization of several basaltic magma batches with similar major and trace elements compositions. At 930 Ma, the HBG suite displays a narrower range in ISr (0.7027 - 0.7056) than in Nd(t) (+1.97 down to -4.90) suggesting some assimilation of a Rb-depleted lower crust (AFC process) or/and source variability. An age of 929 ± 47 Ma is given by a Rb-Sr isochron on the Holum granite (Sri = 0.7046 ±0.0006, MSWD = 1.7). Geothermobarometers indicate a low pressure of emplacement (1.3-2.7 kbar) and an oxygen fugacity close to NNO. High liquidus temperatures are given by the apatite saturation thermometer (1005°C to 1054 °C) and are in agreement with results from other studies. The basaltic parent magmas of the HBG suite are partial melts of an hydrous mafic, potassic source lying either in the lithospheric upper mantle or in the mafic lower crust derived from it. This contrasts with the 930 Ma anorthosite-mangerite-charnockite suite (AMC) of the Rogaland Province for which a depleted lower crustal anhydrous gabbronoritic source has been indicated. The present data imply the penecontemporaneous melting of two contrasting sources in southern Norway. The source duality could result from an increasing degree of metamorphism (amphibolite to granulite) from East to West, an horizontal stratification of the lower crust or from the stratification of the lithosphere (melting of the lower crust or upper mantle). It may also indicate that the AMC and HBG suites formed in two distinct crustal segments. The linear alignment of the HBG suite along the Mandal-Ustaoset shear zone suggests that a linear uprise of the asthenosphere, following a lithospheric delamination under this structure, could be the vector of the mantle heat. [less ▲]

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See detailPetrology of the Lyngdal granodiorite (southern Norway) and the role of fractional crystallization in the genesis of Proterozoic rapakivi-like granites
Bogaerts, Michel; Scaillet, Bruno; Liégeois, Jean-Paul ULg et al

in Precambrian Research (2003), 124(2-4), 149-184

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See detailSr, Nd isotopes and geochemistry of the Bayuda Desert high-grade metamorphic basement (Sudan): An early Pan-African oceanic convergent margin, not the edge of the East Saharan ghost craton?
Küster, D.; Liégeois, Jean-Paul ULg

in Precambrian Research (2001), 109(1-2), 1-23

The high-grade metamorphic basement of the Bayuda Desert is situated at the inferred transition between the juvenile Neoproterozoic mainly greenschist facies Arabian-Nubian Shield (ANS) and the pre ... [more ▼]

The high-grade metamorphic basement of the Bayuda Desert is situated at the inferred transition between the juvenile Neoproterozoic mainly greenschist facies Arabian-Nubian Shield (ANS) and the pre-Neoproterozoic mainly amphibolite facies domain of the East Saharan Ghost Craton. New geochemical and Sr-Nd isotope data reveal that this basement in Bayuda constituted a Neoproterozoic oceanic convergent margin succession with limited and probably late input of old material. Within this series, garnet amphibolites and epidote-biotite gneisses have geochemical characteristics of HFSE-depleted tholeiitic basalts and low- to medium-K dacites and rhyodacites, indicating magmatism in an oceanic island arc or back-arc basin environment. This magmatism occurred at 806 ± 19 Ma (Sm-Nd 11 WR isochron), similar in age to arc magmatism in the ANS. Leucocratic gneisses, muscovite schists and garnet-biotite schists form the dominant meta-sedimentary rocks of the study area. They were primarily derived from two different sources: volcanogenic sediments from a Neoproterozoic island arc (TDM Nd model ages between 790 and 900 Ma) and terrigeneous sediments from an older continental source (TDM Nd model ages up to 2100 Ma). The volcanosedimentary succession was metamorphosed under amphibolite facies conditions prior to 670 Ma, probably at approximately 700 Ma. The high-grade metamorphism is related to a frontal collisional event that also produced syn-collisional peraluminous granites preserved as muscovite-biotite gneisses. Meta-igneous rocks from eastern Bayuda have εNd values at 806 Ma of + 5.2 ± 0.4, indicating a less depleted mantle source (crustal contamination can be excluded) than the neighbouring Gabgaba-Gebeit terrane (εNd, ca. + 7) from the Arabian-Nubian shield. Less depleted mantle source is also known at Jebel Moya to the south, and inside the Arabian-Nubian Shield to the southeast of Bayuda. Lithological and structural similarities (dominantly northeast striking foliation) with the Bayuda Desert succession occur in many parts of central and western Sudan, suggesting a comparable geodynamic evolution. It is proposed that a Neoproterozoic oceanic convergent margin (Bayuda type succession) collided at approximately 700 Ma to the northwest with the East Saharan ghost craton, whose easternmost limit must lie below or more to the west than previously thought. © 2000 Elsevier Science B.V. [less ▲]

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See detailDyke swarms in the Pan-African basement from the Alpine Danubian window : new field and geochemical investigation in southern Carpathians (Romania)
Femenias, Olivier; Demaiffe, Daniel; Liégeois, Jean-Paul ULg et al

in Journal of Conference Abstracts (2001), 6

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See detailGeochemistry of granitoids from the south Carpathians: A review
Berza, Tudor; Andar, Petre; Tatu, Mihai et al

in Anuarul Institutului Geologic al României (2000), 71

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See detailThe crustal tongue melting model and the origin of massive anorthosites
Duchesne, Jean-Clair ULg; Liégeois, Jean-Paul ULg; Vander Auwera, Jacqueline ULg et al

in Terra Nova (1999), 11

Recent detailed field studies in several anorthosite complexes have shown that anorthosites are frequently linked with weakness zones in the crust which favour their emplacement at mid-crust levels ... [more ▼]

Recent detailed field studies in several anorthosite complexes have shown that anorthosites are frequently linked with weakness zones in the crust which favour their emplacement at mid-crust levels. Recent experimental data have also shown that the parent magma compositions of various anorthosite massifs lie on thermal highs in the relevant phase diagrams, indicating that these magmas cannot be derived by fractionation of peridotitic mantle melts but rather are produced by melting of gabbronoritic sources. In the Sveconorwegian province terrane boundaries have been traced in deep seismic profiles to Moho offsets or to tongues of lower crustal material underthrust to depths of 40-50 km. We therefore suggest that the parent magmas of anorthosite massifs are produced by melting of gabbronoritic rocks from the lower crust that had been thrust into the mantle by collision of terranes. [less ▲]

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