The working halves of cores from Holes 1202A and 1202B were sampled using U-channels at the ODP Gulf Coast Repository in College Station, Texas. The U-channels were then shipped to the Paleomagnetism Laboratory at the University of California, Davis, where the measurements were made.
Natural remanent magnetization (NRM) and anhysteretic remanent magnetization (ARM) were measured at 1-cm intervals using an automated 2G Enterprises model 755R cryogenic magnetometer (Weeks et al., 1993; Verosub, 1998). Initially the samples were stepwise demagnetized in peak alternating fields (AFs) of 0, 20, 30, 40, 50, and 60 mT, and the NRM was measured after each step. An ARM was then imparted using a peak AF of 100 mT and a direct bias field of 0.05 mT. The samples were then stepwise demagnetized with peak AFs of 0, 10, 20, 30, 40, 50, and 60 mT.
Low-field magnetic susceptibility (MS) was measured every centimeter using a Bartington susceptibility meter and a field surface probe. This process required the U-channels to be opened in order to place the surface probe directly onto the sediment.
The temperature variation of MS (up to a maximum temperature of 700ºC) was measured on 13 bulk samples evenly spaced along Hole 1202B using a furnace-equipped Kappabridge KLY-3 at the Istituto Nazionale di Geofisica e Vulcanologia in Rome, following procedures described by Hrouda (1994). Hysteresis parameters were measured at University of California, Davis, using a Princeton Measurements Corporation alternating gradient magnetometer.