Four holes (Holes 1110A through 1110D) were drilled at Site 1110. Physical properties measurements were only conducted on APC cores from this site (Cores 180-1110A-1H and 2H and 180-1110B-1H) because of the very low recovery of hard rock in the XCB-cored interval and the fact that the recovered material consisted of clasts devoid of their matrix. At Site 1111, one hole (Hole 1111A) was drilled by RCB technique to a total depth of 173.7 mbsf. Again, physical properties measurements were limited by low core recovery. At Site 1112, total recovery was less than 1 m. Sparse physical properties data were collected, which are included in the data tables of this combined site summary. However, because there are so few data, Site 1112 is neither included in the figures nor discussed in the text. No physical properties measurements were made at Site 1113, again because of the low recovery.
Where applicable, measurements included MST readings (i.e., magnetic susceptibility, gamma-ray attenuation porosity evaluator [GRAPE] density, and natural gamma-ray count) and thermal conductivity measurements on unsplit cores, as well as index properties, PWS velocities, and sediment strength on split cores. Compilations of index property, velocity, thermal conductivity, and strength data are located in Tables T15, T16, and T17 (also in ASCII format in the ASCII TABLES directory).
All index properties data are summarized in Table T15. A full compilation of GRAPE data is presented with the MST measurement data set on the accompanying Lamont-Doherty Earth Observatory (LDEO) CD-ROM. Data from Site 1110 are limited, covering the interval from 0 to 9.5 mbsf. GRAPE bulk density increases from about 1.40 to 1.50 g·cm-3 at the seafloor to ~2.10 g·cm-3 at a depth of ~9 mbsf (Fig. F26). Measurements on discrete samples are generally consistent with the GRAPE data (Fig. F26). Grain density averages 2.70 g·cm-3 at Site 1110, which reflects the mineralogical composition of the predominantly calcareous clays, silty clays, and silts of lithostratigraphic Unit I (see "Lithostratigraphy"). Grain density shows a maximum value of 2.85 g·cm-3 at ~9 m, where bulk density is also elevated. Porosity reflects bulk and grain density variations and decreases within the upper 10 mbsf from an initial value of 80% at the seafloor. A minimum value of 44% occurs at the depth of the highest bulk and grain densities (Fig. F26).
In Hole 1111A, GRAPE density decreases from values around 1.80 g·cm-3 at a depth of ~70 mbsf to 1.40 g·cm-3 on average at ~140 mbsf (Fig. F27). Unlike the GRAPE densities that show considerable scatter, bulk densities from the index properties range only from 1.55 to 1.70 g·cm-3 between 70 and 140 mbsf. The index property data should be less affected by core disturbance than the GRAPE densities and, as a result, should be considered more reliable. Grain densities from Site 1111 average 2.70 g·cm-3. Porosity ranges from 59% to 62% at 60 mbsf to between 65% and 68% at depths greater than 120 mbsf (Fig. F28). Interpretation of this porosity increase with depth should be conducted with caution because recovery was very limited.
The P-wave velocity was measured using the P-wave logger (PWL) on the MST, the PWS1 and PWS2 insertion probe system, and the PWS3 contact probe system. Because of the poor quality of the PWL data, only PWS1, PWS2, and PWS3 results will be discussed. All pertinent velocity data are listed in Table T16.
The PWS1 and PWS2 insertion probe system was used to measure the transverse and longitudinal (i.e., along the core axis) P-wave velocity in unconsolidated oozes and clays from Holes 1110A and 1110B. The velocities were consistent within these 10-m intervals, ranging between 1500 m·s-1 and 1594 m·s-1 (Table T16). In Hole 1111A, data collected from Cores 180-1111A-8R, 11R, and 13R through 16R show relatively constant velocities of 1450 m·s-1 to 1605 m·s-1 (at depths of 65-145 mbsf).
Thermal conductivity data presented in Table T17 were all obtained from unsplit cores recovered from Holes 1110A, 1110B, and 1111A. Three repeat measurements per interval were conducted (Table T17). Thermal conductivities of the uppermost sediments range between 0.8 and 1.0 W·m-1·ºC-1, which is in agreement with results from similar sediments at previous locations (e.g., "Physical Properties" in the "Site 1109" chapter). Thermal conductivity values of 0.45 to 0.85 W·m-1·ºC-1 were measured at depths between 70 and 150 mbsf of Hole 1111A. The lower end of this range is probably invalid data, reflecting void space and disaggregation of the core within the liner.
Undrained shear strength and compressibility measurements were conducted on split cores from Sites 1110 and 1111 using the motorized miniature vane-shear device and the pocket penetrometer, respectively. The data from both sites are presented in Figure F28 and are listed in Table T18.
Both peak and residual undrained shear strength were measured in RCB cores from Site 1111. Failure of the semi-indurated clays and silts from 70 to 100 mbsf occurred at 20-40 kPa (Fig. F28). Residual strength values ranged from 5 to 20 kPa for the same depth interval. Below 100 mbsf, the sediment was too firm to insert the vane shear device into the split core.
Unconfined compressive strength (2 Su) was measured at the very top of Site 1110 with results varying between almost zero kPa (in soupy intervals) and ~20 kPa. Below 70 mbsf in Hole 1111A, strength increases from 22 to 100 kPa at ~135 mbsf, but occasionally peaks to 180 kPa within the well-lithified silt layers. A gradual increase in strength with depth can be seen, although outliers exist and the data are limited (Fig. F28).
Magnetic susceptibility measurements (MSM) were routinely conducted as part of the MST measurement of sediment cores from Sites 1110 and 1111. The entire MSM data set is presented as part of the MST compilation in ASCII format on the accompanying LDEO CD-ROM.
Similar to results from previous sites on Leg 180, (e.g., "Physical Properties" in the "Site 1109" chapter), some of the spikes in the susceptibility curve relate to the occurrence of relatively coarse grained sediment (Fig. F29). Within the nannofossil ooze (0-4.6 mbsf), thin (<2.5-cm-thick) sand layers exist as part of a series of fining-upward sequences (see "Lithostratigraphy"). Many of these sand layers correspond to susceptibility spikes, highlighted in Figure F29A (Holes 1110A and 1110B).
Natural gamma-ray (NGR) count was recorded from a small number of core sections at Sites 1110 and 1111. Insufficient information from Site 1111 precluded the recognition of any trends or relationships. The data from Holes 1110A and 1110B show minor scatter and range between 10 and 20 c/s (Fig. F29B). However, a broad NGR peak occurs at 5.7-6.9 mbsf and corresponds with a silt layer (see Fig. F29, orange/dark gray stipple, and "Lithostratigraphy;" see also "Core Descriptions" content list for core photos). Further, the nannofossil ooze shows little NGR response (Fig. F29, pink/intermediate gray stipple), which is in contrast to the volcaniclastic sediments that appear below 4.5 mbsf (Fig. F29, yellow/light gray stipple). The full NGR data set can be found as part of the MST compilation in ASCII format on the accompanying LDEO CD-ROM.