We built a continuous meters composite depth (mcd) scale and a splice (as defined in the "Composite Section" in the "Explanatory Notes" chapter) that range from the top of Core 184-1145C-1H to the bottom of Section 21X-7. The splice and the mcd scale extend continuously from 0.0 to 132.58 mcd. Extension of a continuous splice below this interval was precluded by incomplete core recovery and alignment of core gaps. However, as described below and in the "Composite Section" in the "Explanatory Notes" chapter, we were able to construct a discontinuous ("floating") mcd scale and splice for the interval spanning 139.8 to 210.0 mcd.
The mcd scale and the splice are based on the stratigraphic correlation of whole-core multisensor track (MST) and split-core color spectral reflectance (CSR) data (lightness, L*) collected at 4- to 5-cm intervals (see "Physical Properties" for details). From the MST, we used magnetic susceptibility (MS), gamma-ray attenuation (GRA) bulk density, and natural gamma radiation (NGR) data. These data, and the splice constructed from them, are presented on the mcd scale in Figures F1, F2, F3, and F4 (also as Synergy Software KaleidaGraph plots and Microsoft Excel data files [see the "Supplementary Materials" contents list]; the spliced records are also available in ASCII format). The depth offsets that comprise the mcd scale are given in Table T3 (also in ASCII format). The splice tie points (Table T4, also in ASCII format) should be used as a guide for detailed postcruise sampling.
Magnetic susceptibility data were the most useful stratigraphic tool for correlation at this site; the MS profiles for the three holes are extremely similar, even at very fine (centimeter) scales.
We constructed the mcd scale by assuming that the uppermost sediment (the "mudline") in Core 184-1145C-1H was the sediment/water interface. This core, the "anchor" in the composite depth scale, has the same depth on both the mbsf and mcd scales. We correlated downhole from this anchor, core by core, until we reached 132 mcd. At this point, aligned core gaps prevented further downhole construction of the continuous mcd scale and splice.
Although the cores below 132 mcd could not be tied directly to the continuous composite depth scale and thus the splice, they could be correlated with each other. We were able to place these cores on a discontinuous composite depth scale. This "floating" scale is not tied to the overlying mcd scale (and thus back to the mudline). Instead, the positions of the cores are adjusted such that correlative features match. We chose Core 184-1145B-16X as the top of the floating splice. The depth of this core on the mcd scale is based on the overlying continuous mcd scale. Cores at similar depths from adjacent holes were mapped to Core 184-1145B-16X; correlation then progressed downhole, as in the construction of the continuous mcd scale.