Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere.
International audience The northernmost part of Scotland - the Hebridean Terrane - is formed of Archean rocks originally being part of the Laurentian North Atlantic Craton. The geological history of the terrane is well recognised, however details of its internal structure remain unknown. The Eocene...
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ftinsu:oai:HAL:insu-03669367v1 2023-12-17T10:33:09+01:00 Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. Buczko, Daniel Matusiak-Małek, Magdalena Upton, Brian J. G. Ntaflos, Theodoros Aulbach, Sonja Grégoire, Michel Puziewicz, Jacek Géosciences Environnement Toulouse (GET) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) à renseigner, Unknown Region 2022-05-16 https://insu.hal.science/insu-03669367 https://doi.org/10.5194/egusphere-egu2020-14255 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-egu2020-14255 insu-03669367 https://insu.hal.science/insu-03669367 BIBCODE: 2020EGUGA.2214255B doi:10.5194/egusphere-egu2020-14255 22nd EGU General Assembly https://insu.hal.science/insu-03669367 22nd EGU General Assembly, 0000, à renseigner, Unknown Region. ⟨10.5194/egusphere-egu2020-14255⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/conferenceObject Conference papers 2022 ftinsu https://doi.org/10.5194/egusphere-egu2020-14255 2023-11-22T17:31:32Z International audience The northernmost part of Scotland - the Hebridean Terrane - is formed of Archean rocks originally being part of the Laurentian North Atlantic Craton. The geological history of the terrane is well recognised, however details of its internal structure remain unknown. The Eocene (Faithfull et al. 2012, JGS) Loch Roag monchiquite (Lewis Island) sampled deep-seated lithologies, providing insight on evolution and geological structure of the deeper lithosphere of the Hebridean terrane. The monchiquite comprises abundant xenoliths of ultramafic, mafic and felsic rocks. The peridotitic xenoliths represent pieces of Archean mantle underlying marginal parts of the North Atlantic Craton, whereas the origin of non-peridotitic lithologies is uncertain.The studied suite of samples comprises two groups: 1) "xenoliths" of diorites (plagioclase, clinopyroxene, orthopyroxene, apatite, opaques) and biotite clinopyroxenites (+apatite), 2) "megacrysts" of clinopyroxene and K-feldspar, both with inclusions of clinopyroxene, biotite and apatite. Megacrysts of alkali-rich feldspar associated with corundum and HFSE-bearing minerals, and composite xenoliths formed of pyroxenite and K-feldspar-rich lithology have also been described from this locality (Menzies et al., 1986, Geol. Soc. Australia Spec. Pub.; Upton et al., 2009, Mineral. Mag.).We interpret the "xenoliths" as products of crystallization of fractionated mafic melt(s). The primary character of Sr isotopic ratios in plagioclase (87Sr/86Sr <0.702) suggests that parental melt of those lithologies originated from melting of depleted lithospheric mantle sources. The "megacrysts" represent fragments of disintegrated alkaline pegmatite(s) formed from melt of plausible mantle origin, possibly enriched (87Sr/86Sr in feldspar >0.704).Trace element composition, similar Sr isotopic ratios of minerals and textural features of "xenoliths" and "megacrysts" groups suggest their close genetic relationship. This geochemical resemblance may reflect crystallisation ... Conference Object Lewis Island North Atlantic Institut national des sciences de l'Univers: HAL-INSU Lewis Island ENVELOPE(134.367,134.367,-66.100,-66.100) Menzies ENVELOPE(61.911,61.911,-73.437,-73.437) |
institution |
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collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Buczko, Daniel Matusiak-Małek, Magdalena Upton, Brian J. G. Ntaflos, Theodoros Aulbach, Sonja Grégoire, Michel Puziewicz, Jacek Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience The northernmost part of Scotland - the Hebridean Terrane - is formed of Archean rocks originally being part of the Laurentian North Atlantic Craton. The geological history of the terrane is well recognised, however details of its internal structure remain unknown. The Eocene (Faithfull et al. 2012, JGS) Loch Roag monchiquite (Lewis Island) sampled deep-seated lithologies, providing insight on evolution and geological structure of the deeper lithosphere of the Hebridean terrane. The monchiquite comprises abundant xenoliths of ultramafic, mafic and felsic rocks. The peridotitic xenoliths represent pieces of Archean mantle underlying marginal parts of the North Atlantic Craton, whereas the origin of non-peridotitic lithologies is uncertain.The studied suite of samples comprises two groups: 1) "xenoliths" of diorites (plagioclase, clinopyroxene, orthopyroxene, apatite, opaques) and biotite clinopyroxenites (+apatite), 2) "megacrysts" of clinopyroxene and K-feldspar, both with inclusions of clinopyroxene, biotite and apatite. Megacrysts of alkali-rich feldspar associated with corundum and HFSE-bearing minerals, and composite xenoliths formed of pyroxenite and K-feldspar-rich lithology have also been described from this locality (Menzies et al., 1986, Geol. Soc. Australia Spec. Pub.; Upton et al., 2009, Mineral. Mag.).We interpret the "xenoliths" as products of crystallization of fractionated mafic melt(s). The primary character of Sr isotopic ratios in plagioclase (87Sr/86Sr <0.702) suggests that parental melt of those lithologies originated from melting of depleted lithospheric mantle sources. The "megacrysts" represent fragments of disintegrated alkaline pegmatite(s) formed from melt of plausible mantle origin, possibly enriched (87Sr/86Sr in feldspar >0.704).Trace element composition, similar Sr isotopic ratios of minerals and textural features of "xenoliths" and "megacrysts" groups suggest their close genetic relationship. This geochemical resemblance may reflect crystallisation ... |
author2 |
Géosciences Environnement Toulouse (GET) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) |
format |
Conference Object |
author |
Buczko, Daniel Matusiak-Małek, Magdalena Upton, Brian J. G. Ntaflos, Theodoros Aulbach, Sonja Grégoire, Michel Puziewicz, Jacek |
author_facet |
Buczko, Daniel Matusiak-Małek, Magdalena Upton, Brian J. G. Ntaflos, Theodoros Aulbach, Sonja Grégoire, Michel Puziewicz, Jacek |
author_sort |
Buczko, Daniel |
title |
Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
title_short |
Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
title_full |
Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
title_fullStr |
Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
title_full_unstemmed |
Caledonian magmatism record within Hebridean Terrane? Loch Roag dyke (Lewis Island, northern Scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
title_sort |
caledonian magmatism record within hebridean terrane? loch roag dyke (lewis island, northern scotland) non-peridotitic xenoliths and megacrysts as messengers from deep lithosphere. |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://insu.hal.science/insu-03669367 https://doi.org/10.5194/egusphere-egu2020-14255 |
op_coverage |
à renseigner, Unknown Region |
long_lat |
ENVELOPE(134.367,134.367,-66.100,-66.100) ENVELOPE(61.911,61.911,-73.437,-73.437) |
geographic |
Lewis Island Menzies |
geographic_facet |
Lewis Island Menzies |
genre |
Lewis Island North Atlantic |
genre_facet |
Lewis Island North Atlantic |
op_source |
22nd EGU General Assembly https://insu.hal.science/insu-03669367 22nd EGU General Assembly, 0000, à renseigner, Unknown Region. ⟨10.5194/egusphere-egu2020-14255⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-egu2020-14255 insu-03669367 https://insu.hal.science/insu-03669367 BIBCODE: 2020EGUGA.2214255B doi:10.5194/egusphere-egu2020-14255 |
op_doi |
https://doi.org/10.5194/egusphere-egu2020-14255 |
_version_ |
1785587064102715392 |