| Abstract: | Abstract— Meteorite magnetic records constitute physical evidence of processes acting during early solar system evolution. Consequently, the validation of these records is important in meteorite research. The first step in the validation process should be the REM value. The REM value is the ratio of natural remanence (NRM) to saturation remanent magnetization imparted by a 1 T magnetic field (SIRM). The REM values range over 3 to 4 orders of magnitude for stony meteorites and for chondrules from Allende (C3V‐S1), Bjurböle (L4‐S1), and Chainpur (LL3‐S1) meteorites. The REM values computed from published NRM and SIRM data identify many orders of magnitude range in the REM values including REM values >100 × 10?3. These data suggest a dependence for the NRM intensity on the curatorial location from which the sample was obtained. Any earth rock acquiring thermoremanent magnetization (TRM) in the geomagnetic field has a restricted range in REM mostly between 5 and 50 × 10?3, the exception being the mineral hematite in the multidomain size range. The only terrestrial samples with REM much greater than 100 × 10?3 are those struck by lightning. The REM value provides a physical basis for recognition between valid records and those that “might be contaminated.” The isothermal remanence acquisition (RA) curve is presented as a contamination curve that allows an indication of the level of magnetic field contamination required to give the computed “REM” (RM/SIRM) value. In the case of the Bjurböle and Chainpur chondrules, with REM values >100 × 10?3, the RA curve indicates that unrealistically large contamination magnetic fields would be required to give REM values greater than 100 × 10?3. This would suggest contamination other than by a hand magnet that is normally available to an experimenter. This would require an explanation that would involve large magnetic fields during chondrule formation, or some extraordinary remanence acquisition mechanism that remains to be described. Magnetic contamination experiments, using ～80 and ～40 mT magnets, demonstrate that the “REM” values and extent of modification of the magnetic vector record are mineralogy dependent, and this is mostly related to the amount and characteristics of the mineral tetrataenite. The complexity of the meteorite records suggest validation of the record as a first step. The REM value is the first physical statement that can be made in this validation. |
