Figure F36. Basalt-sample Zijderveld plots. A. AF demagnetization of Sample 191-1179D-11R-1, 17–19 cm. This sample never reaches a stable direction, as shown on an equal area stereonet (circle inset). B. Thermal demagnetization of Sample 191-1179D-18R-4, 53–55 cm. This sample shows nearly univectorial decay after removal of an overprint at temperatures <300°C.