Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins
Rifting near hotspots results in mantle melting to create thick mafic igneous crust at volcanic rifted margins (VRMs). This mafic crust is transitional between rifted continental crust with mafic intrusions landward and oceanic crust into which it grades seaward. Seismic velocities, crustal drilling...
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crcansciencepubl:10.1139/cjes-2016-0039 2024-06-23T07:53:57+00:00 Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins Karson, Jeffrey A. Polat, Ali 2016 http://dx.doi.org/10.1139/cjes-2016-0039 http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjes-2016-0039 http://www.nrcresearchpress.com/doi/pdf/10.1139/cjes-2016-0039 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 53, issue 11, page 1205-1215 ISSN 0008-4077 1480-3313 journal-article 2016 crcansciencepubl https://doi.org/10.1139/cjes-2016-0039 2024-06-13T04:10:49Z Rifting near hotspots results in mantle melting to create thick mafic igneous crust at volcanic rifted margins (VRMs). This mafic crust is transitional between rifted continental crust with mafic intrusions landward and oceanic crust into which it grades seaward. Seismic velocities, crustal drilling, and exhumed margins show that the upper crust in these areas is composed of basaltic lava erupted in subaerial to submarine conditions intruded by downward increasing proportions of dikes and sparse gabbroic intrusions. The lower crust of these regions is not exposed but is inferred from seismic velocities (Vp > 6.5 km/sec) and petrological constraints to be gabbroic to ultramafic in composition. Limited access to crustal sections generated along VRMs have raised questions regarding the composition and structure of this transitional crust and how it evolves during the early stages of rifting and subsequent seafloor spreading. Active processes in Iceland provide a glimpse of subaerial spreading with the creation of a thick (40–25 km) mafic igneous crust that may be analogous to the transitional crust of VRMs. Segmented rift zones that propagate away from the Iceland hotspot, migrating transform fault zones, and rift-parallel strike-slip faults create a complex plate boundary zone in the upper, brittle crust. These structures may be decoupled from underlying lower crustal gabbroic rocks that are capable of along-axis flow that smooths-out crustal thickness variations. Similar processes may be characteristic of the early history of VRMs and volcanic hotspot ridges related to rifting and seafloor spreading proximal to hotspots. Article in Journal/Newspaper Iceland Canadian Science Publishing Canadian Journal of Earth Sciences 53 11 1205 1215 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
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English |
description |
Rifting near hotspots results in mantle melting to create thick mafic igneous crust at volcanic rifted margins (VRMs). This mafic crust is transitional between rifted continental crust with mafic intrusions landward and oceanic crust into which it grades seaward. Seismic velocities, crustal drilling, and exhumed margins show that the upper crust in these areas is composed of basaltic lava erupted in subaerial to submarine conditions intruded by downward increasing proportions of dikes and sparse gabbroic intrusions. The lower crust of these regions is not exposed but is inferred from seismic velocities (Vp > 6.5 km/sec) and petrological constraints to be gabbroic to ultramafic in composition. Limited access to crustal sections generated along VRMs have raised questions regarding the composition and structure of this transitional crust and how it evolves during the early stages of rifting and subsequent seafloor spreading. Active processes in Iceland provide a glimpse of subaerial spreading with the creation of a thick (40–25 km) mafic igneous crust that may be analogous to the transitional crust of VRMs. Segmented rift zones that propagate away from the Iceland hotspot, migrating transform fault zones, and rift-parallel strike-slip faults create a complex plate boundary zone in the upper, brittle crust. These structures may be decoupled from underlying lower crustal gabbroic rocks that are capable of along-axis flow that smooths-out crustal thickness variations. Similar processes may be characteristic of the early history of VRMs and volcanic hotspot ridges related to rifting and seafloor spreading proximal to hotspots. |
author2 |
Polat, Ali |
format |
Article in Journal/Newspaper |
author |
Karson, Jeffrey A. |
spellingShingle |
Karson, Jeffrey A. Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins |
author_facet |
Karson, Jeffrey A. |
author_sort |
Karson, Jeffrey A. |
title |
Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins |
title_short |
Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins |
title_full |
Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins |
title_fullStr |
Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins |
title_full_unstemmed |
Crustal accretion of thick mafic crust in Iceland: implications for volcanic rifted margins |
title_sort |
crustal accretion of thick mafic crust in iceland: implications for volcanic rifted margins |
publisher |
Canadian Science Publishing |
publishDate |
2016 |
url |
http://dx.doi.org/10.1139/cjes-2016-0039 http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjes-2016-0039 http://www.nrcresearchpress.com/doi/pdf/10.1139/cjes-2016-0039 |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
Canadian Journal of Earth Sciences volume 53, issue 11, page 1205-1215 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/cjes-2016-0039 |
container_title |
Canadian Journal of Earth Sciences |
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53 |
container_issue |
11 |
container_start_page |
1205 |
op_container_end_page |
1215 |
_version_ |
1802645854623891456 |