Thermoremanence acquisition and demagnetization for titanomagnetite under lithospheric pressures
The geological sources of large-scale lithospheric magnetic field anomalies are poorly constrained. Understanding the magnetic behavior of rocks and minerals under the pressures and temperatures encountered at large crustal depths is particularly important in that task. The impact of lithospheric pr...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
10 May 2017
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| In: |
Geophysical research letters
Year: 2017, Volume: 44, Issue: 10, Pages: 4839-4845 |
| ISSN: | 1944-8007 |
| DOI: | 10.1002/2017GL073279 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1002/2017GL073279 Verlag, Volltext: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017GL073279 
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| Author Notes: | Nicolas Launay, Pierre Rochette, Yoann Quesnel, François Demory, Natalia S. Bezaeva, and Dominique Lattard |
| Summary: | The geological sources of large-scale lithospheric magnetic field anomalies are poorly constrained. Understanding the magnetic behavior of rocks and minerals under the pressures and temperatures encountered at large crustal depths is particularly important in that task. The impact of lithospheric pressure is not well known and most of the time neglected in numerical models of the geological sources of magnetic anomalies. We present thermal remanent magnetization (TRM) acquisition and stepwise thermal demagnetization on synthetic titanomagnetite dispersed powder, within an amagnetic cell under hydrostatic pressure up to 1 GPa. TRM is measured after thermal cycling within a cryogenic magnetometer. Pressure-dependent increase in the Curie temperature (initially in the 50-70°C range) is observed, mostly between 0.3 and 0.6 GPa, on the order of 20 K/GPa. TRM intensity also increases with pressure up to 200% at 675 MPa, although the pressure variation with temperature inside the cell complicates the interpretation. |
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| Item Description: | Gesehen am 24.09.2018 |
| Physical Description: | Online Resource |
| ISSN: | 1944-8007 |
| DOI: | 10.1002/2017GL073279 |