Magnetic susceptibility (MS) data collected from Holes 1266A, 1266B, and 1266C at 2.5-cm intervals were used to correlate cores and to construct a composite section for Site 1266 (Fig. F4). The MS data indicate that Cores 208-1266A-7H through 20H and 208-1266C-1H through 14H were cored nearly in parallel, which limited efforts to build a complete composite section for the lower Miocene–Oligocene interval (see "Biostratigraphy"). The XCB cores taken from Holes 1266A, 1266B, and 1266C in the interval ~220–380 mbsf were significantly stretched, squeezed, or disturbed as a result of the coring process and therefore were not suitable for core-to-core correlation. Therefore, a composite depth section for Site 1266 was constructed by assuming a constant growth rate of 15% for Hole 1266A, based on the average growth rates of previous Leg 208 sites, and by adding a mudline offset of 3.14 m that was obtained from correlation with Core 208-1266B-1H (Fig. F5). Subsequently, Cores 208-1266C-1H through 14H were correlated to Cores 208-1266A-7H through 20H, respectively, and Cores 208-1266C-15X and 19X through 21X were extrapolated using, again, a 15% growth rate. Finally, all cores drilled from just below and above the P/E boundary were aligned as closely as possible.
Following construction of the composite depth section for Site 1266, a single spliced record was assembled (Table T2). The lack of overlap between most cores resulted in >30 gaps in the spliced record. The spliced record is complete for the ~297- to 315-meters composite depth (mcd) interval. The P/E boundary interval in the composite was taken from Core 208-1266C-17H. The Site 1266 splice (Table T3) was used to plot other data sets from this site.