Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway
The Seiland Igneous Province (SIP) is situated in western Finnmark, Northern Norway. The SIP comprises a suite of mainly gabbroic plutons, with ultramafic, syenitic and felsic intrusions. The origin of the region has been interpreted in different ways and several tectonic models have been proposed....
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Universitetet i Tromsø
2010
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ftunivtroemsoe:oai:munin.uit.no:10037/2897 2024-06-02T07:54:53+00:00 Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway Rustad, Birgit Katrine 2010-11-22 12400620 bytes application/pdf https://hdl.handle.net/10037/2897 eng eng Universitetet i Tromsø University of Tromsø https://hdl.handle.net/10037/2897 URN:NBN:no-uit_munin_2630 Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0) openAccess Copyright 2010 The Author(s) https://creativecommons.org/licenses/by-nc-sa/3.0 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi petrologi geokjemi: 462 VDP::Mathematics and natural science: 400::Geosciences: 450::Mineralogy petrology geochemistry: 462 GEO-3900 Master thesis Mastergradsoppgave 2010 ftunivtroemsoe 2024-05-07T08:42:34Z The Seiland Igneous Province (SIP) is situated in western Finnmark, Northern Norway. The SIP comprises a suite of mainly gabbroic plutons, with ultramafic, syenitic and felsic intrusions. The origin of the region has been interpreted in different ways and several tectonic models have been proposed. Many different ideas have been suggested about the metamorphic, magmatic and deformation history. New age dates by Roberts (2008) fall within a narrow time range, from 555 Ma to 579 Ma, concluding that the main magmatism took place within ten million years. This is a much shorter period than previously estimated, and the deformation and metamorphic history of the province is therefore reconsidered. In order to better understand the metamorphic and deformation history of the SIP, studies on microstructures, deformation and metamorphism have been carried out in this thesis on a gabbroic pluton and a strongly sheared quartz-feldspathic xenolith of the Seiland Igneous province situated between Langfjord and Øksfjord. Observations from the field and thin sections indicate that the metamorphic and deformational history of these two rocks can be divided into the following stages: contact metamorphism of the country rock caused by the emplacement of the plutonic gabbro (stage I) with subsequent cooling (stage II) and following loading probably as a result of nappe emplacement during the Caledonian orogeny (stage III). Microstructures and metamorphic reactions observed in the rocks support pressure and- temperature estimates given by Elvevold et al. (1994). Both rock types show evidence of a cooling and subsequent solid state deformation. The cooling stage was followed by a higher-pressure metamorphism interpreted to be related to emplacement of a tectonic unit of cold thrust sheet over hot rock during the Caledonian orogeny. The nappe emplacement resulted in the formation of thin mylonitic zones recognized by a strong grain size reduction and a replacement of a pyroxene granulite assemblage to a garnet granulite assemblage. ... Master Thesis Alta Finnmark Northern Norway Øksfjord Finnmark University of Tromsø: Munin Open Research Archive Alta Elvevold ENVELOPE(23.184,23.184,69.878,69.878) Langfjord ENVELOPE(22.363,22.363,70.056,70.056) Norway Seiland ENVELOPE(23.275,23.275,70.430,70.430) Øksfjord ENVELOPE(22.351,22.351,70.239,70.239) |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi petrologi geokjemi: 462 VDP::Mathematics and natural science: 400::Geosciences: 450::Mineralogy petrology geochemistry: 462 GEO-3900 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi petrologi geokjemi: 462 VDP::Mathematics and natural science: 400::Geosciences: 450::Mineralogy petrology geochemistry: 462 GEO-3900 Rustad, Birgit Katrine Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi petrologi geokjemi: 462 VDP::Mathematics and natural science: 400::Geosciences: 450::Mineralogy petrology geochemistry: 462 GEO-3900 |
description |
The Seiland Igneous Province (SIP) is situated in western Finnmark, Northern Norway. The SIP comprises a suite of mainly gabbroic plutons, with ultramafic, syenitic and felsic intrusions. The origin of the region has been interpreted in different ways and several tectonic models have been proposed. Many different ideas have been suggested about the metamorphic, magmatic and deformation history. New age dates by Roberts (2008) fall within a narrow time range, from 555 Ma to 579 Ma, concluding that the main magmatism took place within ten million years. This is a much shorter period than previously estimated, and the deformation and metamorphic history of the province is therefore reconsidered. In order to better understand the metamorphic and deformation history of the SIP, studies on microstructures, deformation and metamorphism have been carried out in this thesis on a gabbroic pluton and a strongly sheared quartz-feldspathic xenolith of the Seiland Igneous province situated between Langfjord and Øksfjord. Observations from the field and thin sections indicate that the metamorphic and deformational history of these two rocks can be divided into the following stages: contact metamorphism of the country rock caused by the emplacement of the plutonic gabbro (stage I) with subsequent cooling (stage II) and following loading probably as a result of nappe emplacement during the Caledonian orogeny (stage III). Microstructures and metamorphic reactions observed in the rocks support pressure and- temperature estimates given by Elvevold et al. (1994). Both rock types show evidence of a cooling and subsequent solid state deformation. The cooling stage was followed by a higher-pressure metamorphism interpreted to be related to emplacement of a tectonic unit of cold thrust sheet over hot rock during the Caledonian orogeny. The nappe emplacement resulted in the formation of thin mylonitic zones recognized by a strong grain size reduction and a replacement of a pyroxene granulite assemblage to a garnet granulite assemblage. ... |
format |
Master Thesis |
author |
Rustad, Birgit Katrine |
author_facet |
Rustad, Birgit Katrine |
author_sort |
Rustad, Birgit Katrine |
title |
Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway |
title_short |
Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway |
title_full |
Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway |
title_fullStr |
Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway |
title_full_unstemmed |
Microstructural and metamoprhic study in rocks of the Seiland Igneous Province between Langfjord and Øksfjord, Alta kommune, Northern Norway |
title_sort |
microstructural and metamoprhic study in rocks of the seiland igneous province between langfjord and øksfjord, alta kommune, northern norway |
publisher |
Universitetet i Tromsø |
publishDate |
2010 |
url |
https://hdl.handle.net/10037/2897 |
long_lat |
ENVELOPE(23.184,23.184,69.878,69.878) ENVELOPE(22.363,22.363,70.056,70.056) ENVELOPE(23.275,23.275,70.430,70.430) ENVELOPE(22.351,22.351,70.239,70.239) |
geographic |
Alta Elvevold Langfjord Norway Seiland Øksfjord |
geographic_facet |
Alta Elvevold Langfjord Norway Seiland Øksfjord |
genre |
Alta Finnmark Northern Norway Øksfjord Finnmark |
genre_facet |
Alta Finnmark Northern Norway Øksfjord Finnmark |
op_relation |
https://hdl.handle.net/10037/2897 URN:NBN:no-uit_munin_2630 |
op_rights |
Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0) openAccess Copyright 2010 The Author(s) https://creativecommons.org/licenses/by-nc-sa/3.0 |
_version_ |
1800744146951995392 |