Anisotropy of magnetic susceptibility of rocks induced by experimental deformation
In the present paper, the influence of the rheological process on the Anisotropy of Magnetic Susceptibility (AMS) of rocks is studied experimentally. The cylindrical samples of quartz-magnetite rock undergo a process under the confining stress of 300 MPa, temperature of 500-800 °C and strain rate of...
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| Format: | Article |
| Language: | English |
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Istituto Nazionale di Geofisica e Vulcanologia (INGV)
1997-06-01
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| Series: | Annals of Geophysics |
| Subjects: | |
| Online Access: | http://www.annalsofgeophysics.eu/index.php/annals/article/view/3923 |
| _version_ | 1818281196659933184 |
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| author | J. Zhou Z. Gu J. Hao |
| author_facet | J. Zhou Z. Gu J. Hao |
| author_sort | J. Zhou |
| collection | DOAJ |
| description | In the present paper, the influence of the rheological process on the Anisotropy of Magnetic Susceptibility (AMS) of rocks is studied experimentally. The cylindrical samples of quartz-magnetite rock undergo a process under the confining stress of 300 MPa, temperature of 500-800 °C and strain rate of 5 ´ 10-5 - 1 ´ 10-4/s. The residual deformation after the above process ranges 9-42%, depending on the experimental condition. It is found that the magnetic susceptibilities and the shapes of magnetic grains in these samples are almost isotropic before deformation. After being deformed, these samples show certain amounts of anisotropy of magnetic susceptibility and the axes of maximum principal susceptibilities deviate from the original ones more or less. Furthermore, the grains become oblate-ellipsoidal and a certain preferred orientation occurs. The grain shape anisotropy seems to be the main reason for AMS formation. It appears that there is a limitation of the piezomagnetic theory in explaining some tectonomagnetic phenomena. The results obtained in this study imply that ductile deformation at high temperature and pressure in depth during a long time-process may result in another kind of response in rock magnetism, which could be a new mechanism of tectonomagnetic variation. |
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| format | Article |
| id | doaj.art-786b6df5b51341f5bcda08be9dcd1c70 |
| institution | Directory Open Access Journal |
| issn | 1593-5213 2037-416X |
| language | English |
| last_indexed | 2024-12-13T00:01:17Z |
| publishDate | 1997-06-01 |
| publisher | Istituto Nazionale di Geofisica e Vulcanologia (INGV) |
| record_format | Article |
| series | Annals of Geophysics |
| spelling | doaj.art-786b6df5b51341f5bcda08be9dcd1c702022-12-22T00:06:24ZengIstituto Nazionale di Geofisica e Vulcanologia (INGV)Annals of Geophysics1593-52132037-416X1997-06-0140210.4401/ag-3923Anisotropy of magnetic susceptibility of rocks induced by experimental deformationJ. ZhouZ. GuJ. HaoIn the present paper, the influence of the rheological process on the Anisotropy of Magnetic Susceptibility (AMS) of rocks is studied experimentally. The cylindrical samples of quartz-magnetite rock undergo a process under the confining stress of 300 MPa, temperature of 500-800 °C and strain rate of 5 ´ 10-5 - 1 ´ 10-4/s. The residual deformation after the above process ranges 9-42%, depending on the experimental condition. It is found that the magnetic susceptibilities and the shapes of magnetic grains in these samples are almost isotropic before deformation. After being deformed, these samples show certain amounts of anisotropy of magnetic susceptibility and the axes of maximum principal susceptibilities deviate from the original ones more or less. Furthermore, the grains become oblate-ellipsoidal and a certain preferred orientation occurs. The grain shape anisotropy seems to be the main reason for AMS formation. It appears that there is a limitation of the piezomagnetic theory in explaining some tectonomagnetic phenomena. The results obtained in this study imply that ductile deformation at high temperature and pressure in depth during a long time-process may result in another kind of response in rock magnetism, which could be a new mechanism of tectonomagnetic variation.http://www.annalsofgeophysics.eu/index.php/annals/article/view/3923anisotropyrheologyductile deformationhigh-temperaturehigh-stress experimentseismomagnetism |
| spellingShingle | J. Zhou Z. Gu J. Hao Anisotropy of magnetic susceptibility of rocks induced by experimental deformation Annals of Geophysics anisotropy rheology ductile deformation high-temperature high-stress experiment seismomagnetism |
| title | Anisotropy of magnetic susceptibility of rocks induced by experimental deformation |
| title_full | Anisotropy of magnetic susceptibility of rocks induced by experimental deformation |
| title_fullStr | Anisotropy of magnetic susceptibility of rocks induced by experimental deformation |
| title_full_unstemmed | Anisotropy of magnetic susceptibility of rocks induced by experimental deformation |
| title_short | Anisotropy of magnetic susceptibility of rocks induced by experimental deformation |
| title_sort | anisotropy of magnetic susceptibility of rocks induced by experimental deformation |
| topic | anisotropy rheology ductile deformation high-temperature high-stress experiment seismomagnetism |
| url | http://www.annalsofgeophysics.eu/index.php/annals/article/view/3923 |
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