Magnetic Susceptibility of Stony Meteorites from the National Meteorite

Introduction: There has been recent interest in using magnetic susceptiblity to characterize and classify meteorites [1,2]. Measurements of magnetic susceptibility represent a fast, non-destructive and systematic way to categorize the rapidly expanding inventory of stony meteorites being discovered on Earth. Previous studies [1,2] have demonstrated that although magnetic susceptibility varies over 4 orders of magnitude, there is consistency between different fragments of the same meteorite and also between different meteorites in the same class. Application of the magnetic susceptibility technique has also been used to identify misclassified meteorites [1,2]. The National Meteorite Collection of Canada is hosted at the Geological Survey of Canada (GSC), which is part of Natural Resources Canada. This collection contains 2700 meteorite specimens belonging to 1100 different meteorites. Among these are 730 different stony meteorites. The Canadian collection thus represents an opportunity to apply and expand the magnetic susceptibility approach initiated by Rochette and co-workers [1,2]. In this paper we report initial results from the Canadian collection. We present magnetic susceptibility data for 194 specimens from 108 different stony meteorites. For 11 meteorites we analyzed multiple specimens (for a total of 97). In addition, our equipment and measurement protocol allowed us to investigate two additional parameters, which were not part of previous meteorite studies [1,2], frequency dependence and anisotropy. We evaluated the frequency dependence by measuring specimens at two frequencies, 19000 and 825 Hz. Our method for approximating anistoropy is discussed below.