Paleomagnetic investigations of Leg 196 Hole 1173B cores conducted during Leg 197 consisted of measurements of natural remanent magnetization, stepwise alternating-field (AF) demagnetizations and subsequent remanence measurements, and measurements of bulk magnetic susceptibility. The remanence of oriented discrete samples from the working-half sections was primarily measured using a 2G Enterprises DC-Superconducting Quantum Interference Device (SQUID) magnetometer (Model 760R). The 2G SQUID magnetometer is equipped with an in-line AF demagnetizer (Model 2G600), which can demagnetize samples to peak fields of 80 mT. Both the magnetometer and AF demagnetizer are interfaced with a PC-compatible computer and are controlled by 2G's Long Core software (National Instruments). Some discrete samples were also measured using a Molspin Minispin spinner magnetometer. A DTECH D-2000 AF demagnetizer was available for stepwise demagnetization of those discrete samples measured with the Molspin magnetometer. The DTECH demagnetizer is capable of peak fields up to 200 mT. Bulk magnetic susceptibilities for discrete samples were measured using a Geofyzika Brno Kappabridge KLY-2 magnetic susceptibility meter. Calibrations of these instruments were based on shipboard standards and standards from the University of Rochester.
The standard ODP core orientation convention (fig. 8 in Shipboard Scientific Party, 1991a; fig. 8 in Shipboard Scientific Party, 1997) was applied. The convention is such that the +z-axis of the sample is parallel downhole to the z-axis of the drill core. With the split face of the drill core representing the y-z plane, the x-axis is then perpendicular to the split face and is directed into the working half of the core. The x-axis is used as the reference "geomagnetic" north for the definition of magnetic declination values. Discrete minicores were marked with an arrow in the -z-axis (uphole) direction on the plane representing the split surface of the working half.
Discrete samples were taken from basalt rocks by drilling cylindrical minicores (~10 cm3) with a water-cooled drill bit attached to a standard drill press. Minicores were oriented following the convention discussed above.
4This section was written during Leg 197. Leg 197 Contributor addresses can be found under "Leg 197 Contributors" in the preliminary pages of the volume.