Measurements of whole core taken at Site 899 included magnetic susceptibility, Gamma-Ray Attenuation Porosity Evaluator (GRAPE) bulk density, and thermal conductivity. Compressional-wave velocities were measured in split cores with the Digital Sound Velocimeter (DSV) in unlithified sediments and in discrete samples with the Hamilton Frame Velocimeter in consolidated sediments and crystalline rock. Undrained shear-strength was measured in split sediment cores, and electrical resistivity was measured in split sediment cores and drilled "minicores" from crystalline rock. Index properties were calculated from wet and dry masses and wet and dry volumes.
Index properties were determined using gravimetric methods (Table 18; Fig. 52). The estimated uncertainties for density and porosity are ±0.02 g/cm3 and ±2%, respectively. Bulk and grain densities and porosity show great variability downhole. Offsets and changes in slope can be correlated with distinct changes in lithology. Gravimetrically determined bulk densities increase from a low of 1.5 g/cm3 at the top of the cored interval of Hole 899A (81.5 mbsf) to about 1.9 g/cm3 at a depth of 170 mbsf, with a corresponding decrease in porosity from about 70% to 50%. Grain densities over this range are uniform and average 2.8 g/cm3.
Between 170 and 230 mbsf, bulk densities and porosities are scattered. A zone of high bulk densities and low porosities between 200 and 240 mbsf, at the base of Hole 899 A, lies below the contact between lithostratigraphic Subunits IIA and IIB. Grain density through this zone is uniform.
Just below 230 mbsf the bulk densities are lower, and the porosities higher, than in Unit I. Bulk density then increases from about 1.85 g/cm3 at 230 mbsf to 2.15 g/cm3 at 370 mbsf (bottom of Unit III), while porosity decreases from 50% to 40%. Grain densities maintain an average value near 2.8 g/cm3 over this range.
Feldspathic sandstones at the base of Unit III yield relatively low bulk densities and high porosities. Grain densities are unusually high in these sediments samples, which may contain ferruginous minerals and basaltic clasts.
The boundary between lithostratigraphic Units III and IV (369.9 mbsf) is marked by abrupt changes in all index properties (Fig. 52). Porosity decreases sharply from 40% to 0%-10% at a depth of 390 mbsf, and grain density decreases to about 2.58 g/cm3. Bulk density dominantly reflects the decrease in porosity; it approaches and sometimes exceeds the calculated grain density at this depth (this probably indicates the range of measurement error at 0% porosity). The downhole trend in grain density appears to correlate with the degree of calcitization of the serpentinized peridotite breccia unit that makes up Unit IV, reflecting differences in the densities of calcite (2.72 to 2.9 g/cm3) and serpentine (2.55 g/cm3).
Bulk densities were also estimated from whole-core GRAPE measurements taken in all sections recovered from Holes 899A and 899B. In the sedimentary section, the maximum GRAPE densities within an interval of about 10 m give the best estimate of the corresponding gravimetrically determined bulk density (Boyce, 1973; Gealy, 1971).
The visually estimated maximum densities are indicated by the curve in Figure 52. In the upper sedimentary section, between 81.5 and 131.6 mbsf, the average estimated density is 1.9 g/cm3. Below 131.7 mbsf, which coincides with the boundary between lithostratigraphic Unit I and Subunit IIA(see "Lithostratigraphy and Petrology" section, this chapter), the bulk density decreases abruptly to an average of 1.8 g/cm3 and remains fairly constant down to a depth of about 180 mbsf. Between 200 and 365 mbsf, a net increase in bulk density from 1.8 to 2.0 g/cm3 can be seen. Below 365 mbsf, the cores are highly fractured and do not fill the core liner, which prevented us from applying an adequate volumetric correction (see "Explanatory Notes" chapter, this volume). This is reflected in the large scatter observed in the data points.
Electrical resistivity was measured at intervals of 0.5 to 0.75 m in all split cores from the sedimentary section and in drilled minicores in the breccia and other hard rocks. Formation factors were calculated for the interval down to 370 mbsf.
An average formation factor of 3.5 characterizes the upper sedimentary section between 80 and 130 mbsf (Fig. 52). The latter depth corresponds to the boundary between lithostratigraphic Unit I and Subunit IIA(see "Lithostratigraphy and Petrology" section, this chapter). Below this, the formation factor increases downhole to an average of 8 at 180 mbsf. Between 200 and 270 mbsf, values exhibit a larger scatter around a mean of 5.5; this is followed by a steep increase from 8 to 13 in the interval between 270 and 320 mbsf. In the lower- most sedimentary section, the formation factor is scattered around a mean of 8.
Above 400 mbsf as well as below 490 mbsf, electrical resistivity in the brecciated and crystalline rocks of Unit IV (Fig. 53) is relatively low (Cores 149-899B-19R and -28R), with values that range from 10 to 125 
m. Between these two zones, electrical resistivities from 150 to 350 m were observed, with three local maxima of about 775 m between 410 and 420 mbsf. Two of these values were measured in large clasts of serpentinized peridotite, rather than breccia, and the third minicore was transected by a large calcite vein.
Undrained shear strength was measured in Cores 149-899A-lR to -10R (Fig. 54). Peak shear strength shows a general downhole increase from about 40 kPa at 80 mbsf to about 160 Kpa at 170 mbsf. Variations in peak strength values (e.g., Cores 149-899A-1R through -5R) probably are controlled by lithologic variations.
Discrete acoustic velocity was measured in sediment samples from each core recovered from Holes 899A and 899B, except for the wash core (Table 19). The DSV was used for Cores 149-899A-1R to -9R (82-159 mbsf) to measure the vertical velocity. The Hamilton Frame Velocimeter was used to measure velocities in sediment samples taken from Cores 149-899A-9R to -899B-15R (159-364 mbsf). Velocities in these samples were measured in three mutually orthogonal directions (see "Explanatory Notes" chapter, this volume). Compressional-wave velocity in crystalline rock from Cores 149-899B-16R to -35R (373-548 mbsf) was measured in minicores in the horizontal direction (Hy) with the Hamilton Frame Velocimeter. Repeated measurements of selected samples and calibration standards suggest an accuracy of 2% to 3% for the velocity measurements.
Discrete acoustic velocity measurements in the sedimentary section show a general increase with depth, from about 1600 m/s at 82 mbsf to 1750 m/s at 364 mbsf (Fig. 55). The vertical velocity shows a reasonably linear trend having a slope of 0.62 s-1, with a correlation coefficient of 0.85. The horizontal velocities show similar downhole variations. Acoustic anisotropy is generally less than 4%, which is less than the estimated error.
Compressional-wave velocities in Unit IV range from 3000 to 6800 m/s (Fig. 56). Velocities of less than 4000 m/s occur within brown serpentinized breccia at depths of less than 390 mbsf (Cores 149-899B-16R to -18R), and beneath the breccia at depths greater than 490 mbsf (Cores 149-899B-29R to -35R). Samples from intervening depths in Cores 149-899B-19R to -26R mostly have velocities greater than 4400 m/s. The single velocity greater than 6800 m/s in Figure 56 is from a sample in which a 2-cm-wide calcite vein ran along the axis of the minicore.
Magnetic susceptibility was measured at intervals of 3 to 5 cm in all cores collected at Site 899. The results are discussed in the "Paleomagnetism" section (this chapter).
Thermal conductivity was measured in alternate sections of all cores from Site 899. The mean error associated with these measurements was estimated as ±0.2 W/(m·K). In the sedimentary section, the thermal conductivity values show no significant change with depth.
Between 80 and 360 mbsf, thermal conductivity values of about 1.35 W/(m·K) were observed (Fig. 57; Table 20). At 370 mbsf, an abrupt increase in thermal conductivity to 1.8 W/(m·K) marks the boundary between the soft sediments and the more lithified rocks and breccias. Data scatter increases below 370 mbsf, reflecting the lithologic heterogeneity (see "Lithostratigraphy and Petrology" section, this chapter).
The physical properties data obtained at Site 899 are heterogeneous, reflecting the variations in consolidation and lithology. Clearly, the most important discontinuity is the contact between the breccia units and the overlying sedimentary units. Variations in physical properties in the overlying sediments also suggest the existence of smaller-scale heterogeneities in lithology and/or consolidation.
