Index properties measurements were made at a resolution of one sample for every two sections in the cores from all Site 1124 holes. Index properties were determined by a gravimetric method (see "Physical Properties" in the "Explanatory Notes" chapter). Values of measured index properties (void ratio, porosity, water content, bulk density, and grain density) are presented in Table T17 (also in ASCII format). The properties show two fairly homogeneous sediment sections occurring between 20 and 178 mbsf (lithostratigraphic Subunits IA and IB), and between 178 and 280 mbsf (lithostratigraphic Subunit IC; see "Lithostratigraphy"). In both these units, the index properties profiles are nearly vertical with little variation (Fig. F29). No downhole increasing trend occurred in these two homogeneous sections. The porosity in Subunit IC is generally 15% lower than in Subunits IA and IB (above 178 mbsf), where sediments are apparently more compacted. An abrupt change in the index properties occurred at 178 mbsf; at this depth, lithification of the mud and nannofossil ooze into mudstone and nannofossil chalk, respectively, begins (see "Lithostratigraphy"). Below 310 mbsf, wet-bulk density increases from 1.5 to 2.0 g/cm3 downhole, while porosity decreases from 65% to 40% downhole. Two abrupt changes in the index properties occurred at 310 and 390 mbsf, possibly reflecting zones of depositional hiatuses or erosion, although this cannot be substantiated from the biostratigraphic results. Lithostratigraphic Unit IV, a dark mudstone (between 420 and 430 mbsf), is characterized by lower bulk density and higher porosity relative to the chalks above and below.
The shipboard physical properties program at Site 1124 included nondestructive measurements of bulk density, magnetic susceptibility, and natural gamma-ray activity on whole sections of all cores using the MST (Fig. F30). Magnetic susceptibility was measured at 4-cm intervals and at high sensitivity (4-s measurement time) in all Site 1124 holes. High-amplitude fluctuations in magnetic susceptibility above 200 mbsf are associated with the occurrence of tephra layers (see "Lithostratigraphy"). Magnetic susceptibility increases below 178 mbsf, the boundary between lithostratigraphic Subunits IB and IC, and then decreases below 310 mbsf. Lithostratigraphic Units II and III are characterized by very low magnetic susceptibility values; this finding is consistent with the high carbonate content of the nannofossil chalk (see "Organic Geochemistry"). Below 420 mbsf, magnetic susceptibility increases abruptly corresponding to the high clay content of the dark mudstone in Unit IV. Below the dark mudstone (430 mbsf), magnetic susceptibility decreases again.
Natural gamma radiation was measured with a 15-s count every 14 cm in all Site 1124 holes. Natural gamma radiation values range from 0 to 40 counts/s. High values of natural gamma radiation indicate a relatively high clay mineral content. The low natural gamma radiation observed below 310 mbsf (except between 420 and 440 mbsf) indicates less clay-rich sediment than in the upper part of the core. The spikes in natural gamma radiation in the upper part of the section are probably a result of the presence of abundant tephra layers. High natural gamma radiation values occurred between 420 and 430 mbsf and correlate with high magnetic susceptibility. These features are associated with the dark mudstone of Unit IV. Lithostratigraphic Unit VI is characterized by an abrupt increase in natural gamma radiation below 430 mbsf.
GRAPE bulk-density measurements were made at 4-cm intervals at all Site 1124 holes. A comparison of GRAPE density with the wet-bulk density determined from discrete samples shows general agreement although GRAPE density values are overall higher than bulk density obtained by index property measurements in the upper portion of the cores (APC cores). The P-wave velocity measurements (PWL) were made at 4-cm intervals at all Site 1124 holes. The PWL measurements were only collected from APC cores. High P-wave velocity peaks from Hole 1124C are associated with tephra layers.
Compressional-wave (P-wave) velocity was measured perpendicular to the long axis of the core from XCB coring (below 178 mbsf) using the Hamilton frame velocimeter. P-wave velocity values are fairly constant in Subunit IC (between 178 and 280 mbsf). Nearly constant P-wave velocity can also be seen in the index properties record between 178 and 280 mbsf. Gradually increasing P-wave velocity values occurred below 310 mbsf. This change is not reflected in magnetic susceptibility and natural gamma radiation records, but a similar increase does occur in the GRAPE density profile. These changes indicate increasing overburden and lithification downhole. Lithostratigraphic Units II and III are distinguished by a reversal of P-wave velocity occurring at 410 mbsf. The dark mudstone of Unit IV is characterized by low P-wave velocities.
Four downhole temperature measurements with the Adara temperature tool were taken at the position of Cores 181-1124C-5H, 7H, 9H, and 11H. The Adara temperature tool yielded only one good-quality temperature estimate of 5.66°C from Core 9H (Fig. F31). Temperature records collected from Cores 7H and 11H were unusable. This bad reading might have been produced by sensor movement caused by the ship's motion. Accordingly, the temperature values from Cores 7H and 11H are provided only for reference (6.12°C and 6.56°C at Core 7H, and 6.87°C at Core 11H). On Core 9H (93.7 mbsf), the Adara temperature tool measured a value that reached 15.24° C just after the penetration, because of the effect of frictional heat production; in the same location, and at near equilibrium with the in situ sediments, it recorded 7.62°C just before pulling out. Based on temperature equilibration curves from Cores 7H, 9H, and 11H, the temperature estimate at the mudline is 0.92°C. Thermal conductivity was measured in the shipboard laboratory on the same core as the Adara temperature tool was used in; four measurements were made per core. A thermal gradient of 5.21°C/100 m was then calculated from the Adara tool and thermal conductivity measurements. Using an average thermal conductivity of 0.944 W/(m·K), heat-flow was estimated to be 0.049 W/m2. The thermal gradient and the estimated heat-flow value are both lower than those determined from sediments recovered from Site 1120. However, the values were only determined from two Adara temperature profiles and should be used with caution.