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Stratigraphic correlation and composite section

Magnetic susceptibility, GRA density, and NGR data collected from cores of Holes U1359A–U1359D were used to construct the composite section for Site U1359. The NGR and magnetic susceptibility measurements were primarily used for core to core correlation and to construct the composite section (Figs. F61, F62, F63). The depth offsets that define the composite section for Site U1359 are given in Table T15.

There are two gaps in the upper 30 m of the composite record. This is a direct result of intensive sampling for microbiologic and geochemical analysis in the first two cores from Hole U1359B and the lack of recovery in the second core in Hole U1359C. The gaps in the composite record occur at ~10.9 mcd (between Cores 318-U1359A-2H and 3H) and ~29.8 mcd (between Cores 318-U1359B-4H and 318-U1359C-4H).

Following construction of the composite depth section for Site U1359, a single spliced record was assembled from the aligned core intervals from all four holes (Table T16). The composite data show that the cores from Site U1359 provide two continuous sequences from 36.84 mcd (top of Section 318-U1359A-6H-1) to 162.08 mcd (bottom of Core 318-U1359B-17H) and from 162.29 mcd (top of Core 318-U1359B-18H) to 214.49 mcd (bottom of Core 318-U13459B-22H). Below this depth, Cores 318-U1359B-23H through 24X and 318-U1359D-7R through 48R were appended to the record (Figs. F61, F62, F63; Table T16).

Cores that had been significantly stretched, squeezed, or disturbed by the coring process were not used for the splice. Without a stretching or squeezing correction, all points within each core are offset equally. As a result, some of the patterns are not perfectly aligned between holes (e.g., at ~45 and ~72 mcd in Fig. F61). Thus, the meters composite depth values of the different holes will approximate but not precisely correspond to the same stratigraphic horizon in alternate holes.

The Site U1359 splice (Table T16) can be used as a guide to sample the sedimentary sequence and was used to plot other data sets from this site. The meters composite depth to meters below seafloor growth factors for Holes U1359A–U1359C were ~5%, ~6%, and ~4%, respectively (Fig. F64A, F64B, F64C).