Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica)
Volcanic rocks forming sills, dykes or lava flows may display a magnetic anisotropy derived from the viscous flow during their emplacement. We model a sill as a steady-state how of a Bingham fluid, driven by a pressure gradient in a horizontal conduit, The magma velocity as a function of depth is ca...
Published in: | Geophysical Journal International |
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Format: | Article in Journal/Newspaper |
Language: | English |
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1997
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Online Access: | http://hdl.handle.net/11586/40729 https://doi.org/10.1111/j.1365-246X.1997.tb04083.x |
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ftunivbari:oai:ricerca.uniba.it:11586/40729 2024-04-14T08:04:04+00:00 Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) DRAGONI M LANZA R TALLARICO, Andrea Dragoni, M Lanza, R Tallarico, Andrea 1997 http://hdl.handle.net/11586/40729 https://doi.org/10.1111/j.1365-246X.1997.tb04083.x eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:A1997WC16600017 volume:128 firstpage:230 lastpage:240 numberofpages:11 journal:GEOPHYSICAL JOURNAL INTERNATIONAL http://hdl.handle.net/11586/40729 doi:10.1111/j.1365-246X.1997.tb04083.x info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0030923230 info:eu-repo/semantics/article 1997 ftunivbari https://doi.org/10.1111/j.1365-246X.1997.tb04083.x 2024-03-21T18:08:13Z Volcanic rocks forming sills, dykes or lava flows may display a magnetic anisotropy derived from the viscous flow during their emplacement. We model a sill as a steady-state how of a Bingham fluid, driven by a pressure gradient in a horizontal conduit, The magma velocity as a function of depth is calculated from the motion and constitutive equations. Vorticity and strain rate are determined for a reference system moving with the fluid, The angular velocity and the orientation of an ellipsoidal magnetic grain immersed in the fluid are calculated as functions of time or strain. Magnetic susceptibility is then calculated for a large number of grains with a uniform distribution of initial orientations. It is shown that the magnetic lineation oscillates in the vertical plane through the magma flow direction, and that the magnetic foliation plane changes periodically from horizontal to vertical. The results are compared with the magnetic fabric of Ferrar dolerite sills (Victoria Land, East Antarctica) derived from low-field susceptibility measurements. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Victoria Land Università degli Studi di Bari Aldo Moro: CINECA IRIS Bingham ENVELOPE(-63.400,-63.400,-69.400,-69.400) East Antarctica Victoria Land Geophysical Journal International 128 1 230 240 |
institution |
Open Polar |
collection |
Università degli Studi di Bari Aldo Moro: CINECA IRIS |
op_collection_id |
ftunivbari |
language |
English |
description |
Volcanic rocks forming sills, dykes or lava flows may display a magnetic anisotropy derived from the viscous flow during their emplacement. We model a sill as a steady-state how of a Bingham fluid, driven by a pressure gradient in a horizontal conduit, The magma velocity as a function of depth is calculated from the motion and constitutive equations. Vorticity and strain rate are determined for a reference system moving with the fluid, The angular velocity and the orientation of an ellipsoidal magnetic grain immersed in the fluid are calculated as functions of time or strain. Magnetic susceptibility is then calculated for a large number of grains with a uniform distribution of initial orientations. It is shown that the magnetic lineation oscillates in the vertical plane through the magma flow direction, and that the magnetic foliation plane changes periodically from horizontal to vertical. The results are compared with the magnetic fabric of Ferrar dolerite sills (Victoria Land, East Antarctica) derived from low-field susceptibility measurements. |
author2 |
Dragoni, M Lanza, R Tallarico, Andrea |
format |
Article in Journal/Newspaper |
author |
DRAGONI M LANZA R TALLARICO, Andrea |
spellingShingle |
DRAGONI M LANZA R TALLARICO, Andrea Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) |
author_facet |
DRAGONI M LANZA R TALLARICO, Andrea |
author_sort |
DRAGONI M |
title |
Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) |
title_short |
Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) |
title_full |
Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) |
title_fullStr |
Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) |
title_full_unstemmed |
Magnetic anisotropy produced by magma flow: Theoretical model and experimental data from Ferrar dolerite sills (Antarctica) |
title_sort |
magnetic anisotropy produced by magma flow: theoretical model and experimental data from ferrar dolerite sills (antarctica) |
publishDate |
1997 |
url |
http://hdl.handle.net/11586/40729 https://doi.org/10.1111/j.1365-246X.1997.tb04083.x |
long_lat |
ENVELOPE(-63.400,-63.400,-69.400,-69.400) |
geographic |
Bingham East Antarctica Victoria Land |
geographic_facet |
Bingham East Antarctica Victoria Land |
genre |
Antarc* Antarctica East Antarctica Victoria Land |
genre_facet |
Antarc* Antarctica East Antarctica Victoria Land |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:A1997WC16600017 volume:128 firstpage:230 lastpage:240 numberofpages:11 journal:GEOPHYSICAL JOURNAL INTERNATIONAL http://hdl.handle.net/11586/40729 doi:10.1111/j.1365-246X.1997.tb04083.x info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0030923230 |
op_doi |
https://doi.org/10.1111/j.1365-246X.1997.tb04083.x |
container_title |
Geophysical Journal International |
container_volume |
128 |
container_issue |
1 |
container_start_page |
230 |
op_container_end_page |
240 |
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1796300448636862464 |