At Site 1079, three holes were cored with the APC to a maximum depth of 129.9 meters below seafloor (mbsf). At the last sections of Holes 1079A and 1079B, as well as at several sections of Hole 1079C, flow-in structures were observed. These are described as pseudobedding parallel to the core liner and 1- to 2-cm-wide tubular structures penetrating the entire section (see "Lithostratigraphy" section, this chapter). Additional core disturbances caused by gas expansion are common at Site 1079.
The physical properties data set for Site 1079 included GRAPE density, P-wave velocity, and magnetic susceptibility, which were measured on the MST at 2-cm (Hole 1079A) and 4-cm intervals (Holes 1079B and 1079C). Natural gamma emissions were measured with a 32-cm sample interval on the MST. Color reflectance data were measured at 2-cm (Hole 1079A) and 4-cm intervals (Holes 1079B and 1079C). The correlation of features present in the physical and visual properties measurements of adjacent holes was used to demonstrate continuity of the stratigraphic sequence drilled and to establish a meters composite depth (mcd) scale for Site 1079. The continuity of the stratigraphic sequence was shown to 132 mcd.
At Site 1079, magnetic susceptibility and wet bulk density (GRAPE) 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 or 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 Figure 13 and Figure 14 were processed as described above.
The stratigraphic correlation among Holes 1079A, 1079B, and 1079C is excellent up to ~75 mcd. A core overlap of ~50% at Hole 1079C compared with Holes 1079A and 1079B allowed for a good correlation of sedimentary features expressed in the magnetic susceptibility and wet bulk density logs. Below 75 mcd, coring disturbance and, possibly, gas expansion introduced a higher scatter in both data sets used. The magnetic susceptibility log appears to be intensively disturbed between 75 and 132 mcd. The interhole correlation of this parameter was very poor in this depth interval, and the logs show few features suitable for alignment. The GRAPE wet bulk density also exhibits some disturbance from 75 to 132 mcd. Major variations in the density record for Site 1079 are still distinguishable in this parameter. The alignment of these features demonstrates the completeness of the sedimentary sequence drilled at Site 1079 down to 132 mcd. The evaluation of color reflectance data, especially for the problematic interval from 75 to 132 mcd, revealed no additional information compared with GRAPE wet bulk density. The red/blue ratio (650/450 nm) shows a decreased amplitude compared with the Lower Congo Basin sites (see "Lithostratigraphy" section, this chapter, and the "Composite Section" and "Lithostratigraphy" sections in the "Site 1075," "Site 1076," and "Site 1077" chapters, this volume). The total reflectance data (lightness L*) of Site 1079 reveal more variation but are also affected by drilling disturbance (see "Lithostratigraphy" section, this chapter). According to the available data, an application of offsets to cores below ~80 mcd was not justified (Table 6; Fig. 15). Thus, compared with the standard ODP mbsf scale, the final growth of the mcd scale is less than 5% at Site 1079.
The spliced record presented in Figure 14 and Table 7 is continuous to 132 mcd for magnetic susceptibility and GRAPE wet bulk density. It was constructed using cores from Hole 1079A whenever possible. The spliced record could be constructed with very smooth transitions between the core fragments used in the upper half of Site 1079 (i.e., 0 to ~80 mcd; Fig 14).