Open AccessMineral magnetic properties of artificial samples systematically mixed from haematite and magnetite
Author(s) -
Frank Ute,
Nowaczyk Norbert R.
Publication year - 2008
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2008.03821.x
Subject(s) - magnetite , remanence , coercivity , grain size , mineralogy , rock magnetism , saturation (graph theory) , natural remanent magnetization , materials science , geology , analytical chemistry (journal) , magnetization , magnetic field , metallurgy , chemistry , condensed matter physics , mathematics , physics , chromatography , quantum mechanics , combinatorics
SUMMARY Detailed rock magnetic investigations were carried out on a set of samples with defined ratios of haematite and magnetite. The measured parameters provide a reference for interpreting common rock magnetic parameters in investigations of sediments. The contribution of haematite to the magnetic fraction must exceed 95 wt‐% of the magnetic fraction when mixed with magnetite in order to visibly influence grain size and coercitivity indicative magnetic parameters. Coercivity of remanence ( B CR ) and coercive force ( B C ) do not change in the same way with increasing haematite content, which results in a peak B CR / B C value at around 99.5 wt‐% haematite. Variations in haematite content can be ignored when interpreting most rock magnetic parameters, especially grain size indicative parameters for samples where haematite contents range from 0 to 98 wt‐%. The S‐ratio is still the most sensitive parameter for estimating the relative amount of haematite in magnetite/haematite mixtures. A combination of S‐ratio, the saturation isothermal remanent magnetization divided by the low field magnetic susceptibility (SIRM/κ LF ) and B CR is the most effective way to identify haematite in natural samples . Our results agree with literature data and fill the gap between results obtained either from pure magnetite or haematite with comparable grain sizes.