Paleomagnetic systematics of ordinary chondrites

The investigation shows that the decrease in intensity and the increase in stability of natural remanent magnetization (NRM) to alternating field (AF) demagnetization roughly parallel the decrease in Ni-Fe metal content and the corresponding enrichment of the metal phases in Ni. The stability of NRM within a chemical type appears to decrease with increasing degree of metamorphism, a feature interpretable in terms of composition, size, and shape of metal grains. Paleofield intensities required to imprint the NRM as thermo-chemical remanence are in the range from 0.01 to 0.3 Oe.