The anisotropy of magnetic susceptibility (AMS) for each sample was calculated by inserting the sample into a Geofyzika Brno KLY_2 KappaBridge alternating-current (AC) susceptibility bridge in 15 different orientations. The software provided by Geofyzika Brno determined the anisotropy tensor from the measurements. Table T3 lists the depth, F-statistics for anisotropy of magnetic susceptibility (Fig. F2), declinations and inclinations of the maximum, intermediate, and minimum axes of the AMS ellipsoid (Fig. F3) and their 95% confidence angles (Figs. F4 and F5), the mean magnetic susceptibility, the normed principal susceptibilities and their uncertainties, the components of the anisotropy of magnetic susceptibility tensor, and measures of anisotropy based on those principal susceptibilities.
AMS was determined for 51 samples from Unit I, 20 samples from Unit II, and 15 samples from Unit III. In Unit I, 42 of the 51 samples have significantly anisotropic AMS ellipsoids (F > 3.84). Of the 42 anisotropic samples, there are 25 significantly prolate/triaxial AMS ellipsoids (F12 > 4.25), 30 significantly oblate/triaxial AMS ellipsoids (F23 > 4.25), and 2 AMS ellipsoids that are neither significantly prolate/triaxial nor significantly oblate/triaxial (Samples 191-1179C-5H-6, 38–40 cm, and 17H-4, 120–122 cm). There are 15 triaxial AMS ellipsoids, 10 prolate AMS ellipsoids, and 15 oblate AMS ellipsoids.
In Unit II, all 20 samples are significantly anisotropic and significantly oblate/triaxial. Half of the samples are significantly prolate/triaxial, which means there are 10 triaxial AMS ellipsoids and 10 oblate AMS ellipsoids. In Unit III, all 15 samples are significantly anisotropic and significantly oblate/triaxial. Ten of the samples are also significantly prolate/triaxial, so there are 10 triaxial AMS ellipsoids and 5 oblate AMS ellipsoids.
The measures of anisotropy defined and listed in Table T3 are shown vs. depth below seafloor in Figure F6. There is a shift in AMS ellipsoid shape (T, q) from approximately equal distributions of prolate and oblate in sedimentary Unit I to dominantly oblate ellipsoids in sedimentary Units II and III (Fig. F6A, F6B).
The measure of anisotropy L (Fig. F6C; Table T2) is very close to isotropic for Units I, II, and III. The other measures of anisotropy (F, P, and Pj) shown in Figures F6D–F6F are all close to isotropic in Unit I and more anisotropic in Units II and III. There is an increase in anisotropy beginning with Core 191-1179C-21H (229.3 mbsf).