Two holes with a maximum penetration of 205.2 mbsf were cored with the APC at Site 1077. Hole 1077C was abandoned after retrieval of Core 175-1077-3H at 22 mbsf. Physical properties and color reflectance data were measured at 2-cm (Hole 1077A) and 4-cm (Hole 1077B and Hole 1077C) intervals. The correlation of features present in the physical and visual properties measurements of adjacent holes were used to demonstrate the completeness of the local stratigraphic sequence drilled and to establish a depth scale in terms of meters composite depth (mcd) for Site 1077. The continuity of the stratigraphic sequence was shown from 15 to 211 mcd. A gap of 1.2 m at 14 mcd is caused by poor recovery (60%) of Cores 175-1077A-2H and 175-1077C-2H (Fig. 15).
At Site 1077, magnetic susceptibility and red/blue ratio (650 nm/450 nm) calculated from color reflectance data were used to establish the mcd scale. The data sets were extensively processed before being used for correlation. Suspect measurements were eliminated by thresholding the data, followed by additional processing using a linear approximation filter algorithm. For 10 measurements, taken over an interval of 20 to 40 cm, a linear regression and the standard deviation of the data were calculated. Measurements with values outside twice the standard deviation were reassigned the linearly approximated value. Finally, the data were smoothed using a Gaussian filter with a length of 12 cm. All data shown in Fig. 15 and Fig. 16 were processed as described above.
The double APC coverage at Site 1077 did not allow for the demonstration of a complete sedimentary record over the entire 205 mbsf drilled. In addition, the cores from Holes 1077A and 1077B did not overlap in an optimal fashion. The determination of the composite depth scale relies on the identification of features common to physical properties measurements in overlapping sections of adjacent cores. Where this was not possible, the driller's depth (in mbsf) was taken as composite depth (mcd). Cores 175-1077A-2H through 5H, and 175-1077B-2H, 6H, and 7H remained at their respective depth in mbsf (Fig. 14, Fig. 16, Fig. 17; also see Table 8). The strategy for the construction of the composite section was to combine depth information from Holes 1077A and 1077B in an optimal fashion. Where justified, the overlap between adjacent cores was increased to avoid the inclusion of data from the top and bottom ends of individual cores in the spliced record. In fact, an improvement of core overlap was possible only in a few depth intervals. The resulting growth of the mcd scale compared with the standard ODP mbsf scale is ~6%.
The spliced record presented in Figure 16 and Table 9 is continuous between 15 and 211 mcd for magnetic susceptibility and GRAPE wet bulk densities. The remaining data gaps within this depth interval are of decimeter to centimeter size and thus are considered negligible. The selection of cores to be included in the spliced record and the placement of tie points was carried out mainly using the composite section of magnetic susceptibility from Site 1077. The strategy for splicing was to construct a continuous spliced record with smooth transitions between individual cores for most of the cored depth interval.