| Autor: |
Nikolaisen, Even S, Harrison, Richard, Fabian, Karl, Church, Nathan, McEnroe, Suzanne A, Sørensen, Bjørn Eske, Tegner, Christian |
| Přispěvatelé: |
Nikolaisen, Even S [0000-0002-8285-2797], Fabian, Karl [0000-0002-3504-3292], Church, Nathan [0000-0001-5426-6224], McEnroe, Suzanne A [0000-0002-0011-6156], Sørensen, Bjørn Eske [0000-0002-9647-1784], Tegner, Christian [0000-0003-1407-7298], Apollo - University of Cambridge Repository |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Nikolaisen, E S, Harrison, R, Fabian, K, Church, N, Mcenroe, S A, Sørensen, B E & Tegner, C 2022, ' Hysteresis parameters and magnetic anisotropy of silicate-hosted magnetite exsolutions ', Geophysical Journal International, vol. 229, no. 3, pp. 1695-1717 . https://doi.org/10.1093/gji/ggac007 |
| Popis: |
SUMMARY Anisotropy of remanent magnetization and magnetic susceptibility are highly sensitive and important indicators of geological processes which are largely controlled by mineralogical parameters of the ferrimagnetic fraction in rocks. To provide new physical insight into the complex interaction between magnetization structure, shape, and crystallographic relations, we here analyse ‘slice-and-view’ focused-ion-beam (FIB) nano-tomography data with micromagnetic modelling and single crystal hysteresis measurements. The data sets consist of 68 magnetite inclusions in orthopyroxene (Mg60) and 234 magnetite inclusions in plagioclase (An63) were obtained on mineral separates from the Rustenburg Layered Suite of the Bushveld Intrusive Complex, South Africa. Electron backscatter diffraction was used to determine the orientation of the magnetite inclusions relative to the crystallographic directions of their silicate hosts. Hysteresis loops were calculated using the finite-element micromagnetics code MERRILL for each particle in 20 equidistributed field directions and compared with corresponding hysteresis loops measured using a vibrating sample magnetometer (VSM) on silicate mineral separates from the same samples. In plagioclase the ratio of remanent magnetization to saturation magnetization (Mrs/Ms) for both model and measurement agree within 1.0 per cent, whereas the coercivity (Hc) of the average modelled curve is 20 mT lower than the measured value of 60 mT indicating the presence of additional sources of high coercivity in the bulk sample. The VSM hysteresis measurements of the orthopyroxene were dominated by multidomain (MD) magnetite, whereas the FIB location was chosen to avoid MD particles and thus contains only particles with diameters |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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