Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism
Magnetic properties from the Reinfjord Ultramafic Complex, in northern Norway, which formed as part of a deep magmatic conduit system, have been investigated to determine the magnetic signature of ultramafic rocks now exposed at the surface and deeper in the lower crust. The dominant carriers in the...
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American Geophysical Union (AGU)
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Online Access: | http://hdl.handle.net/11250/2627234 https://doi.org/10.1029/2018GC008132 |
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ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2627234 2023-05-15T17:43:26+02:00 Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism ter Maat, Geertje McEnroe, Suzanne Church, Nathan Stewart B. Larsen, Rune 2019 http://hdl.handle.net/11250/2627234 https://doi.org/10.1029/2018GC008132 eng eng American Geophysical Union (AGU) Geochemistry Geophysics Geosystems. 2019, 20 (4), 1794-1817. urn:issn:1525-2027 http://hdl.handle.net/11250/2627234 https://doi.org/10.1029/2018GC008132 cristin:1707087 1794-1817 20 Geochemistry Geophysics Geosystems 4 Journal article Peer reviewed 2019 ftntnutrondheimi https://doi.org/10.1029/2018GC008132 2019-11-27T14:09:19Z Magnetic properties from the Reinfjord Ultramafic Complex, in northern Norway, which formed as part of a deep magmatic conduit system, have been investigated to determine the magnetic signature of ultramafic rocks now exposed at the surface and deeper in the lower crust. The dominant carriers in these ultramafic rocks are a chrome‐spinel with Fe‐rich exsolution blebs and exsolution lamellae of magnetite in clinopyroxene. Except locally, in a fault zone and in discrete small fractures, these rocks show only minor to no alteration. We infer that the magnetic oxides characterized here are representative of pristine magnetic carriers in similar rocks deeper in the crust. These oxides can be stable in lower crustal, possibly upper mantle, depths when temperatures are below the Curie temperature of magnetite, taking into account pressure effects. These ultramafic rocks are candidates for potential sources of long‐wavelength anomalies. publishedVersion ©2019. American Geophysical Union. All Rights Reserved. Article in Journal/Newspaper Northern Norway NTNU Open Archive (Norwegian University of Science and Technology) Norway Geochemistry, Geophysics, Geosystems 20 4 1794 1817 |
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Open Polar |
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NTNU Open Archive (Norwegian University of Science and Technology) |
op_collection_id |
ftntnutrondheimi |
language |
English |
description |
Magnetic properties from the Reinfjord Ultramafic Complex, in northern Norway, which formed as part of a deep magmatic conduit system, have been investigated to determine the magnetic signature of ultramafic rocks now exposed at the surface and deeper in the lower crust. The dominant carriers in these ultramafic rocks are a chrome‐spinel with Fe‐rich exsolution blebs and exsolution lamellae of magnetite in clinopyroxene. Except locally, in a fault zone and in discrete small fractures, these rocks show only minor to no alteration. We infer that the magnetic oxides characterized here are representative of pristine magnetic carriers in similar rocks deeper in the crust. These oxides can be stable in lower crustal, possibly upper mantle, depths when temperatures are below the Curie temperature of magnetite, taking into account pressure effects. These ultramafic rocks are candidates for potential sources of long‐wavelength anomalies. publishedVersion ©2019. American Geophysical Union. All Rights Reserved. |
format |
Article in Journal/Newspaper |
author |
ter Maat, Geertje McEnroe, Suzanne Church, Nathan Stewart B. Larsen, Rune |
spellingShingle |
ter Maat, Geertje McEnroe, Suzanne Church, Nathan Stewart B. Larsen, Rune Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism |
author_facet |
ter Maat, Geertje McEnroe, Suzanne Church, Nathan Stewart B. Larsen, Rune |
author_sort |
ter Maat, Geertje |
title |
Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism |
title_short |
Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism |
title_full |
Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism |
title_fullStr |
Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism |
title_full_unstemmed |
Magnetic Mineralogy and Petrophysical Properties of Ultramafic Rocks: Consequences for Crustal Magnetism |
title_sort |
magnetic mineralogy and petrophysical properties of ultramafic rocks: consequences for crustal magnetism |
publisher |
American Geophysical Union (AGU) |
publishDate |
2019 |
url |
http://hdl.handle.net/11250/2627234 https://doi.org/10.1029/2018GC008132 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_source |
1794-1817 20 Geochemistry Geophysics Geosystems 4 |
op_relation |
Geochemistry Geophysics Geosystems. 2019, 20 (4), 1794-1817. urn:issn:1525-2027 http://hdl.handle.net/11250/2627234 https://doi.org/10.1029/2018GC008132 cristin:1707087 |
op_doi |
https://doi.org/10.1029/2018GC008132 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
20 |
container_issue |
4 |
container_start_page |
1794 |
op_container_end_page |
1817 |
_version_ |
1766145496927174656 |