Fig. 3.

Results of the Shaw paleointensity experiments. On the left are the NRM-TRM diagrams which constrain the paleointensity. The magnitude of the laboratory field used to impart a TRM was 30 μT. The inset of each plot shows orthogonal vector plots of AF demagnetization of NRM; squares show projections on the vertical plane, and circles show projections on the horizontal plane with an orientation following the ODP/IODP convention. On the right are the ARM1-ARM2 diagrams which check laboratory alteration. The color of each symbol shows the AF demagnetization step as indicated by the color bar. (a) Successful result from a Leg 153 sample. Demagnetization of this sample was performed by an in-line demagnetizer of cryogenic magnetometers. (b) Successful result from an Exp. 305 sample. (c) Result failed to meet slope = 1 condition in the ARM1-ARM2 plot. (d) Result failed to show characteristic remanence. (e) Result failed to show linearity in the NRM-TRM plot. (f) Result with anomalously low slope in the NRM-TRM plot. Demagnetization of this sample was performed by an in-line demagnetizer of cryogenic magnetometers.