The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton
The geodynamic regime(s) that predominated during the Archaean remains controversial, with the plethora of competing models largely informed by felsic lithologies. Ultramafic-mafic rocks displaying distinctive geochemical signatures are formed in a range of Phanerozoic geotectonic environments. Thes...
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ftdatacite:10.6084/m9.figshare.c.4878588 2023-05-15T17:30:52+02:00 The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton Guice, George L. McDonald, Iain Hughes, Hannah S. R. MacDonald, John M. Faithfull, John W. 2020 https://dx.doi.org/10.6084/m9.figshare.c.4878588 https://geolsoc.figshare.com/collections/The_origin_s_and_geodynamic_significance_of_Archaean_ultramafic-mafic_bodies_in_the_mainland_Lewisian_Gneiss_Complex_North_Atlantic_Craton/4878588 unknown Geological Society of London https://dx.doi.org/10.1144/jgs2020-013 CC BY 4.0 https://creativecommons.org/licenses/by/4.0 CC-BY Geology FOS Earth and related environmental sciences Collection article 2020 ftdatacite https://doi.org/10.6084/m9.figshare.c.4878588 https://doi.org/10.1144/jgs2020-013 2021-11-05T12:55:41Z The geodynamic regime(s) that predominated during the Archaean remains controversial, with the plethora of competing models largely informed by felsic lithologies. Ultramafic-mafic rocks displaying distinctive geochemical signatures are formed in a range of Phanerozoic geotectonic environments. These rocks have high melting points, making them potentially useful tools for investigating Archaean geodynamic processes in highly metamorphosed regions. We present field mapping, petrography, traditional bulk-rock geochemistry, and platinum-group element geochemistry for 12 ultramafic-mafic bodies in the Lewisian Gneiss Complex (LGC), which is a highly metamorphosed fragment of the North Atlantic Craton in northwest Scotland. Our data indicate that most of these occurrences are layered intrusions emplaced into the tonalite-trondhjemite-granodiorite (TTG)-dominated crust prior to polyphase metamorphism, representing a significant re-evaluation of the LGC’s magmatic evolution. Of the others, two remain ambiguous, but one (Loch an Daimh Mor) has some geochemical affinity with abyssal/orogenic peridotites and may represent a fragment of Archaean mantle, although further investigation is required. The ultramafic-mafic bodies in the LGC thus represent more than one type of event/process. Compared with the TTG host rocks, these lithologies may preserve evidence of protolith origin(s), with potential to illuminate tectonic setting(s) and geodynamic regimes of the early Earth. Article in Journal/Newspaper North Atlantic DataCite Metadata Store (German National Library of Science and Technology) |
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topic |
Geology FOS Earth and related environmental sciences |
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Geology FOS Earth and related environmental sciences Guice, George L. McDonald, Iain Hughes, Hannah S. R. MacDonald, John M. Faithfull, John W. The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton |
topic_facet |
Geology FOS Earth and related environmental sciences |
description |
The geodynamic regime(s) that predominated during the Archaean remains controversial, with the plethora of competing models largely informed by felsic lithologies. Ultramafic-mafic rocks displaying distinctive geochemical signatures are formed in a range of Phanerozoic geotectonic environments. These rocks have high melting points, making them potentially useful tools for investigating Archaean geodynamic processes in highly metamorphosed regions. We present field mapping, petrography, traditional bulk-rock geochemistry, and platinum-group element geochemistry for 12 ultramafic-mafic bodies in the Lewisian Gneiss Complex (LGC), which is a highly metamorphosed fragment of the North Atlantic Craton in northwest Scotland. Our data indicate that most of these occurrences are layered intrusions emplaced into the tonalite-trondhjemite-granodiorite (TTG)-dominated crust prior to polyphase metamorphism, representing a significant re-evaluation of the LGC’s magmatic evolution. Of the others, two remain ambiguous, but one (Loch an Daimh Mor) has some geochemical affinity with abyssal/orogenic peridotites and may represent a fragment of Archaean mantle, although further investigation is required. The ultramafic-mafic bodies in the LGC thus represent more than one type of event/process. Compared with the TTG host rocks, these lithologies may preserve evidence of protolith origin(s), with potential to illuminate tectonic setting(s) and geodynamic regimes of the early Earth. |
format |
Article in Journal/Newspaper |
author |
Guice, George L. McDonald, Iain Hughes, Hannah S. R. MacDonald, John M. Faithfull, John W. |
author_facet |
Guice, George L. McDonald, Iain Hughes, Hannah S. R. MacDonald, John M. Faithfull, John W. |
author_sort |
Guice, George L. |
title |
The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton |
title_short |
The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton |
title_full |
The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton |
title_fullStr |
The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton |
title_full_unstemmed |
The origin(s) and geodynamic significance of Archaean ultramafic-mafic bodies in the mainland Lewisian Gneiss Complex, North Atlantic Craton |
title_sort |
origin(s) and geodynamic significance of archaean ultramafic-mafic bodies in the mainland lewisian gneiss complex, north atlantic craton |
publisher |
Geological Society of London |
publishDate |
2020 |
url |
https://dx.doi.org/10.6084/m9.figshare.c.4878588 https://geolsoc.figshare.com/collections/The_origin_s_and_geodynamic_significance_of_Archaean_ultramafic-mafic_bodies_in_the_mainland_Lewisian_Gneiss_Complex_North_Atlantic_Craton/4878588 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://dx.doi.org/10.1144/jgs2020-013 |
op_rights |
CC BY 4.0 https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.6084/m9.figshare.c.4878588 https://doi.org/10.1144/jgs2020-013 |
_version_ |
1766127985718460416 |