Fig. 6

Zero-field warming curves of saturation IRM produced by a field of 5 T at 10 K for six unannealed crushed magnetites. Compared to Fig. 2, the curves are rather featureless, particularly above T_V. Cooling curves were not measured but the remanences after cooling back to 10 K are shown as individual points at the left. In most cases these are virtually identical to the values measured at 300 K, indicating zero recovery of remanence in the second crossing of T_V