Figure 4. AF and thermal demagnetization results characteristic of some of the better sedimentary rock samples from Site 1001 (Samples 165-1001A-49R-2, 28 cm, and 51R-1, 115 cm). AF demagnetization results show that the magnetic mineral carrying the ChRM has a medium-to-high coercivity whereas the drill-string overprint has a low coercivity. This allows the drill-string overprint to be removed by ~15-20 mT. Thermal demagnetization results show that the steep drill-string overprint is removed by ~300°C with the shallow ChRM direction remaining. See Figure 2 caption for diagram descriptions.