Extremely high demands for measurement accuracy in precise determination of frequency-dependent magnetic susceptibility of rocks and soils
Frequency-dependent magnetic susceptibility, which is an important tool for environmental and palaeoclimatologic research, is usually relatively low, mostly less than 15% of the low frequency value and there is a demand for high precision of its measurement. The accuracy required for the susceptibility measurement at individual operating frequencies for precise determination of the parameter characterizing the frequency-dependent susceptibility was investigated theoretically and also experimentally through repeated measurement of artificial specimens and sediments of a loess/palaeosol sequence using the MFK1 Kappabridge. It was found that the variation in the frequency-dependence in the order of 1% is well reproducible and the measurements can be interpreted in terms of magnetic granulometry even in weakly magnetic materials.
Keywordsaccuracy susceptibility frequency dependence
- Borradaile G.J., 2007. Statistics of Earth Science Data: Their Distribution in Time, Space, and Orientation. Springer Verlag, Berlin, Germany.Google Scholar
- Heller F. and Evans M.E., 2003. Environmental Magnetism: Principles and Applications of Enviromagnetics. Academic Press, New York.Google Scholar
- Jelínek V., 1977. The Statistical Theory of Measuring Anisotropy of Magnetic Susceptibility of Rocks and its Application. Geofyzika n.p., Brno, Czech Republic.Google Scholar
- Nagata T., 1961. Rock Magnetism. Maruzen, Tokyo, Japan.Google Scholar
- Pokorný J., Suza P., Pokorný P., Chlupáčová M. and Hrouda F., 2006. Widening power of low-field magnetic methods in the investigation of rocks and environmental materials using the Multi-Function Kappabridge Set. Geophys. Res. Abstr., 8, EGU 06-A-04141.Google Scholar