Based upon correlations among MST measurements of magnetic susceptibility, GRAPE density, and Minolta spectrophotometer measurements, the completeness of the stratigraphic sequence was documented for the upper 141 mcd at Site 1082. Development of this composite depth section follows the procedure described in the "Explanatory Notes" chapter (this volume). All data used for constructing the composite section were measured at 2-cm intervals in Cores 175-1082A-1H through 8H and at 4-cm intervals for the remainder of Hole 1082A, as well as for Holes 1082B and 1082C.
Magnetic susceptibility, GRAPE density, and color reflectance (chromaticity b*) parameters were all used to develop interhole correlations to verify core gaps, though the composite is primarily based upon magnetic susceptibility. Natural gamma ray (NGR) emissions and P-wave velocity were also measured on the MST; however, the coarseness (32-cm measurement interval) for NGR and low signal-to-noise ratio for P-wave velocity precluded their use in constructing the composite section. Measurement quality decreased downhole and required extensive filtering of the data because of core disturbance and gas voids. The filtering procedure is described in the "Composite Section" section, "Site 1075" chapter, this volume.
Hole-to-hole splices constraining intercore gaps for this site were excellent over the entire composite section of 141 mcd (Fig. 14). A composite record below 141 mcd was not possible because the bottom of Hole 1082B was reached and recovery was relatively poor for the XCB-cored portion of Hole 1082A. Although not part of the composite section, magnetic susceptibility and chromaticity data are plotted below 150 mcd in Figure 14.
At Hole 1082C, an interval of 5 m was double-cored in Cores 175-1082C-3H and 4H. Based on magnetic susceptibility, we found an excellent correlation of the lower 5 m of Core 3H to the upper 5 m of Core 4H, as well as to adjacent Core 175-1082A-3H, despite the double coring of Hole 1082C. It should be noted that according to the driller's depth (in mbsf) recorded in the core log, Core 175-1082C-4H overlaps Core 5H by 5 m.
Gaps between successive cores of the same hole average between 1 and 2 m at Site 1082. Gaps are not necessarily actual coring gaps. They may result from the stretching of the mcd scale compared with the mbsf scale as a result of core expansion alone. Between Cores 175-1082C-1H and 2H, a large 4.5-m gap exists.
Continuous overlap of the composite section of Holes 1082A–C enables the construction of a single spliced record constructed from magnetic susceptibility and color reflectance (chromaticity b*; Fig. 15). The splice is composed primarily of Holes 1082A and 1082B and can be used as a sampling guide to ensure a continuous stratigraphic sequence. Tie points between cores of adjacent holes used to construct the splice are given in Table 9. Below 141 mcd, the relative core depths were not adjusted but were simply appended to the composite depth scale.
Because depth adjustments to the whole core are based upon correlation of sedimentary features over a ±2-m window, intracore features outside this window may be offset as a result of core distortions. Thus, some features in the composite record (Fig. 14) may not be aligned between adjacent holes of the composite section. Offsets of the mcd scale relative to the mbsf scale are given in Table 10. These measurements indicate that the composite section is expanded by ~10% relative to the mbsf scale (Fig. 16).