Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland
This paper provides detailed structural data on the faults and intrusions of the eroded Stardalur volcano, in the Esja peninsula at the SW margin of the Icelandic rift, and new lithostratigraphic data on the host rocks. A swarm of centrally-dipping sheets, emplaced with a fan-shaped geometry in sect...
Published in: | Journal of Volcanology and Geothermal Research |
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Language: | English |
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Online Access: | http://hdl.handle.net/10281/1713 https://doi.org/10.1016/j.jvolgeores.2006.11.009 |
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ftunivmilanobic:oai:boa.unimib.it:10281/1713 2024-04-14T08:13:39+00:00 Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland Pasquare, F TIBALDI, ALESSANDRO Pasquare, F Tibaldi, A 2007-03-01 http://hdl.handle.net/10281/1713 https://doi.org/10.1016/j.jvolgeores.2006.11.009 eng eng ELSEVIER SCIENCE BV place:AMSTERDAM info:eu-repo/semantics/altIdentifier/wos/WOS:000245018500009 volume:161 issue:1-2 firstpage:131 lastpage:150 journal:JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH http://hdl.handle.net/10281/1713 doi:10.1016/j.jvolgeores.2006.11.009 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33846653177 Iceland Stardalur Esja sheet swarm regional dyke faults GEO/03 - GEOLOGIA STRUTTURALE info:eu-repo/semantics/article 2007 ftunivmilanobic https://doi.org/10.1016/j.jvolgeores.2006.11.009 2024-03-21T16:23:11Z This paper provides detailed structural data on the faults and intrusions of the eroded Stardalur volcano, in the Esja peninsula at the SW margin of the Icelandic rift, and new lithostratigraphic data on the host rocks. A swarm of centrally-dipping sheets, emplaced with a fan-shaped geometry in section view, depicts an ellipse in plan view with an about E-W major axis. Sheet intensity reaches 80% in one 100-m transect near the central portion of the swarm, where sheets strike E-W with sub-vertical dip. A 200-m-thick, multiply-intrusive body forms a laccolith in the middle of the centrally-dipping sheet swarm, at a higher altitude. Individual intrusive units within this laccolith are sub-vertical and strike E-W in the center, acquiring a sill-like geometry outwards, and were emplaced in a stress field locally dominated by a N-S-directed least principal stress (sigma 3). Within the inclined sheet swarm, the stress tensor rotated in response to an excess magma pressure, probably linked to an underlying magma chamber, which interacted with the tectonic stresses. Crosscutting relationships between the various intrusions and with the host rock indicate that the activity in the central zone of the Stardalur volcano ended with the emplacement of the laccolith. Later eruptions, if they occurred at all, were fed by centrally-dipping sheets. In the final stage, NNE-striking regional vertical dykes and normal faults cut the previous structures in response to dominant regional plate tectonic stresses with a WNW-ESE directed sigma 3 and a NNE-SSW directed intermediate principal stress (sigma 2). (c) 2006 Elsevier B.V. All rights reserved. Article in Journal/Newspaper Iceland Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) Esja ENVELOPE(-21.649,-21.649,64.236,64.236) Stardalur ENVELOPE(-21.482,-21.482,64.210,64.210) Journal of Volcanology and Geothermal Research 161 1-2 131 150 |
institution |
Open Polar |
collection |
Università degli Studi di Milano-Bicocca: BOA (Bicocca Open Archive) |
op_collection_id |
ftunivmilanobic |
language |
English |
topic |
Iceland Stardalur Esja sheet swarm regional dyke faults GEO/03 - GEOLOGIA STRUTTURALE |
spellingShingle |
Iceland Stardalur Esja sheet swarm regional dyke faults GEO/03 - GEOLOGIA STRUTTURALE Pasquare, F TIBALDI, ALESSANDRO Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland |
topic_facet |
Iceland Stardalur Esja sheet swarm regional dyke faults GEO/03 - GEOLOGIA STRUTTURALE |
description |
This paper provides detailed structural data on the faults and intrusions of the eroded Stardalur volcano, in the Esja peninsula at the SW margin of the Icelandic rift, and new lithostratigraphic data on the host rocks. A swarm of centrally-dipping sheets, emplaced with a fan-shaped geometry in section view, depicts an ellipse in plan view with an about E-W major axis. Sheet intensity reaches 80% in one 100-m transect near the central portion of the swarm, where sheets strike E-W with sub-vertical dip. A 200-m-thick, multiply-intrusive body forms a laccolith in the middle of the centrally-dipping sheet swarm, at a higher altitude. Individual intrusive units within this laccolith are sub-vertical and strike E-W in the center, acquiring a sill-like geometry outwards, and were emplaced in a stress field locally dominated by a N-S-directed least principal stress (sigma 3). Within the inclined sheet swarm, the stress tensor rotated in response to an excess magma pressure, probably linked to an underlying magma chamber, which interacted with the tectonic stresses. Crosscutting relationships between the various intrusions and with the host rock indicate that the activity in the central zone of the Stardalur volcano ended with the emplacement of the laccolith. Later eruptions, if they occurred at all, were fed by centrally-dipping sheets. In the final stage, NNE-striking regional vertical dykes and normal faults cut the previous structures in response to dominant regional plate tectonic stresses with a WNW-ESE directed sigma 3 and a NNE-SSW directed intermediate principal stress (sigma 2). (c) 2006 Elsevier B.V. All rights reserved. |
author2 |
Pasquare, F Tibaldi, A |
format |
Article in Journal/Newspaper |
author |
Pasquare, F TIBALDI, ALESSANDRO |
author_facet |
Pasquare, F TIBALDI, ALESSANDRO |
author_sort |
Pasquare, F |
title |
Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland |
title_short |
Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland |
title_full |
Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland |
title_fullStr |
Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland |
title_full_unstemmed |
Structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at Stardalur Volcano, Iceland |
title_sort |
structure of a sheet-laccolith system revealing the interplay between tectonic and magma stresses at stardalur volcano, iceland |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2007 |
url |
http://hdl.handle.net/10281/1713 https://doi.org/10.1016/j.jvolgeores.2006.11.009 |
long_lat |
ENVELOPE(-21.649,-21.649,64.236,64.236) ENVELOPE(-21.482,-21.482,64.210,64.210) |
geographic |
Esja Stardalur |
geographic_facet |
Esja Stardalur |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000245018500009 volume:161 issue:1-2 firstpage:131 lastpage:150 journal:JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH http://hdl.handle.net/10281/1713 doi:10.1016/j.jvolgeores.2006.11.009 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33846653177 |
op_doi |
https://doi.org/10.1016/j.jvolgeores.2006.11.009 |
container_title |
Journal of Volcanology and Geothermal Research |
container_volume |
161 |
container_issue |
1-2 |
container_start_page |
131 |
op_container_end_page |
150 |
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1796311678654087168 |