Evolution of a shear zone before, during and after melting
Partial melt in the deforming mid/lower continental crust causes a strength decrease and drives formation of lithological heterogeneities. However, mechanisms of formation of syn-melt deformation zones and strain partitioning in partially molten rock remain poorly understood. We use field and mi- cr...
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ftdatacite:10.6084/m9.figshare.c.4819494 2023-05-15T17:43:30+02:00 Evolution of a shear zone before, during and after melting Amicia L. Lee Lloyd, Geoffrey E. Torvela, Taija Walker, Andrew M. 2020 https://dx.doi.org/10.6084/m9.figshare.c.4819494 https://geolsoc.figshare.com/collections/Evolution_of_a_shear_zone_before_during_and_after_melting/4819494 unknown Geological Society of London https://dx.doi.org/10.1144/jgs2019-114 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.4819494 https://doi.org/10.1144/jgs2019-114 2021-11-05T12:55:41Z Partial melt in the deforming mid/lower continental crust causes a strength decrease and drives formation of lithological heterogeneities. However, mechanisms of formation of syn-melt deformation zones and strain partitioning in partially molten rock remain poorly understood. We use field and mi- crostructural observations to unravel the evolution of a partial melt shear zone, Seiland Igneous Province, Northern Norway. The Øksfjord shear zone (ØSZ) is one of several paragneiss shear zones present within gabbros of the Seiland Igneous province, formed by syn-intrusive deep crustal shearing during lithospheric extension relating to continental rifting. Microstructures from the ØSZ show evidence for different de- formation conditions. The first phase was active pre-melt and involved deformation at high subsolidus temperatures. This was followed by syn-melt deformation of the shear zone causing a relative strength increase towards the shear zone centre upon crystallisation. The second phase nucleated two parallel shear zones at the edges of the ØSZ, melt textures are absent and microstructures indicate deformation at lower temperatures and higher stresses. In effect, melt migration towards the shear zone centre ultimately led to strengthening of the shear zone core, with post-crystallisation deformation focusing along shear zone margins where significant heterogeneities are present. Article in Journal/Newspaper Northern Norway Øksfjord DataCite Metadata Store (German National Library of Science and Technology) Norway Seiland ENVELOPE(23.275,23.275,70.430,70.430) Øksfjord ENVELOPE(22.351,22.351,70.239,70.239) |
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Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
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topic |
Geology FOS Earth and related environmental sciences |
spellingShingle |
Geology FOS Earth and related environmental sciences Amicia L. Lee Lloyd, Geoffrey E. Torvela, Taija Walker, Andrew M. Evolution of a shear zone before, during and after melting |
topic_facet |
Geology FOS Earth and related environmental sciences |
description |
Partial melt in the deforming mid/lower continental crust causes a strength decrease and drives formation of lithological heterogeneities. However, mechanisms of formation of syn-melt deformation zones and strain partitioning in partially molten rock remain poorly understood. We use field and mi- crostructural observations to unravel the evolution of a partial melt shear zone, Seiland Igneous Province, Northern Norway. The Øksfjord shear zone (ØSZ) is one of several paragneiss shear zones present within gabbros of the Seiland Igneous province, formed by syn-intrusive deep crustal shearing during lithospheric extension relating to continental rifting. Microstructures from the ØSZ show evidence for different de- formation conditions. The first phase was active pre-melt and involved deformation at high subsolidus temperatures. This was followed by syn-melt deformation of the shear zone causing a relative strength increase towards the shear zone centre upon crystallisation. The second phase nucleated two parallel shear zones at the edges of the ØSZ, melt textures are absent and microstructures indicate deformation at lower temperatures and higher stresses. In effect, melt migration towards the shear zone centre ultimately led to strengthening of the shear zone core, with post-crystallisation deformation focusing along shear zone margins where significant heterogeneities are present. |
format |
Article in Journal/Newspaper |
author |
Amicia L. Lee Lloyd, Geoffrey E. Torvela, Taija Walker, Andrew M. |
author_facet |
Amicia L. Lee Lloyd, Geoffrey E. Torvela, Taija Walker, Andrew M. |
author_sort |
Amicia L. Lee |
title |
Evolution of a shear zone before, during and after melting |
title_short |
Evolution of a shear zone before, during and after melting |
title_full |
Evolution of a shear zone before, during and after melting |
title_fullStr |
Evolution of a shear zone before, during and after melting |
title_full_unstemmed |
Evolution of a shear zone before, during and after melting |
title_sort |
evolution of a shear zone before, during and after melting |
publisher |
Geological Society of London |
publishDate |
2020 |
url |
https://dx.doi.org/10.6084/m9.figshare.c.4819494 https://geolsoc.figshare.com/collections/Evolution_of_a_shear_zone_before_during_and_after_melting/4819494 |
long_lat |
ENVELOPE(23.275,23.275,70.430,70.430) ENVELOPE(22.351,22.351,70.239,70.239) |
geographic |
Norway Seiland Øksfjord |
geographic_facet |
Norway Seiland Øksfjord |
genre |
Northern Norway Øksfjord |
genre_facet |
Northern Norway Øksfjord |
op_relation |
https://dx.doi.org/10.1144/jgs2019-114 |
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.4819494 https://doi.org/10.1144/jgs2019-114 |
_version_ |
1766145596403482624 |