The copyright line for this article was changed on 11 August 2014 after original online publication.
Comparison and calibration of nonheating paleointensity methods: A case study using dusty olivine
Article first published online: 10 JUL 2013
©2013. The Authors.
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Geochemistry, Geophysics, Geosystems
Volume 14, Issue 7, pages 2143–2158, July 2013
How to Cite
2013), Comparison and calibration of nonheating paleointensity methods: A case study using dusty olivine, Geochem. Geophys. Geosyst., 14, 2143–2158, doi:10.1002/ggge.20141., , , and (
- Issue published online: 3 SEP 2013
- Article first published online: 10 JUL 2013
- Accepted manuscript online: 15 APR 2013 06:01AM EST
- Manuscript Accepted: 6 APR 2013
- Manuscript Revised: 29 MAR 2013
- Manuscript Received: 23 JAN 2013
- EPSRC and the Cambridge European Trust
- Institute for Rock Magnetism (IRM)
- dusty olivine;
 We present a comparative study of nonheating paleointensity methods, with the aim of determining the optimum method for obtaining paleointensities from “dusty olivine” in chondritic meteorites. The REM method, whereby thermoremanent magnetization (TRM) is normalized by saturation isothermal remanent magnetization (SIRM), is shown to “over normalize” TRM in dusty olivine due to the transformation of stable single-vortex (SV) states to metastable single-domain (SD) states in a saturating field. The problem of over normalization is reduced in the REMc and REM' methods, which more effectively isolate the high-coercivity stable SD component of remanence. A calibration factor of f = 1600 (1000 < f < 2900) is derived for the REM' method. Anhysteric remanent magnetization (ARM) is shown to be a near perfect analogue of TRM in the stable SD component of dusty olivine. ARM normalization of the high-coercivity (100–150 mT) remanence with a calibration factor fARM = 0.91 (0.7 < fARM < 1.2) yields paleofield estimates within ± 30% of the actual field values for SD dominated samples. A Preisach method for simulating TRM acquisition using information extracted from first-order reversal curve (FORC) diagrams is shown to work well for SD dominated samples, but fails when there is a large proportion of SV remanence carriers. The failure occurs because (1) SV states are not properly incorporated into the Preisach distribution of remanence carriers, and (2) the acquisition of TRM by SV states is not properly modeled by the underlying SD thermal relaxation theory.