Empirical scaling law as a tool for absolute paleointensity determination

Abstract:

Empirical scaling law (EPSL, 226, 521-528, 2004) revealed a fundamental linear magnetic relation capable of revealing the magnetizing field during either thermal and/or chemical magnetic remanence acquisition measured at room temperature. Power law relationship with exponent tied to demagnetizing field that is both magnetic minerals and/or shape dependent. Paleointensity vector estimate is done with using the measurement of efficiency of ratios between natural remanent and saturated remanent magnetizations at demagnetized (by alternating magnetic fields) to monotonously increasing levels up to 100 mT. Combining empirical law with the spectrum of alternating-field sample demagnetization allows not only unique view into the history of magnetic fields that were present during the history of the sample but also ability to group the magnetic carriers within sample according to their magnetic resistance towards AF demagnetization. We show how paleomagnetic field can be detected by using this method in Murchison meteorite samples, samples affected by magnetic field from lightning, discharge and geomagnetic field recorded in glass samples of various origins.