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Viscous magnetization of loess/palaeosol samples from Bulgaria

Abstract

The processes of acquisition of viscous remanence and its decay in zero magnetic field are studied for three sets of palaeosol and loess samples. A linear behaviour of VRM vs. log t minus is obtained for 10–104 min. to 30 days of acquisition experiments. Linear correlation between the obtained coefficients of viscous acquisition normalized to saturation magnetization (Sa/Js) or frequency dependent magnetic susceptibility (Sa/χfd%) and the ratio of susceptibility to saturation magnetization (χ/Js), suggests that ultra fine SP/SD grains are mainly involved in the process of viscous acquisition. Non-linear VRM vs. log t behaviour is observed during viscous decay in μ-metal shielded space, being most pronounced for the first 10 min. of the experiment. It is supposed that this phenomena is due to the presence of composite grains (core/shell structure), formed as a result of low-temperature oxidation. The latter increases towards older palaeosol units.

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Correspondence to Diana Jordanova.

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Jordanova, D., Yancheva, G. & Gigov, V. Viscous magnetization of loess/palaeosol samples from Bulgaria. Earth Planet Sp 53, 169–180 (2001). https://doi.org/10.1186/BF03352374

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Keywords

  • Magnetite
  • Loess Sample
  • Magnetic Viscosity
  • Thermoremanent Magnetization
  • Spinner Magnetometer