Construction of the composite and spliced section from Holes 1134A and 1134B followed the methods outlined in "Composite Depths" in the "Explanatory Notes" chapter. Table T3 (also in ASCII format) relates meters below seafloor (mbsf) depth to meters composite depth (mcd) for each core and section at Holes 1134A and 1134B and provides offset values for the conversion of mbsf depths to mcd. The composite section was constructed to a depth of 151.7 mcd and indicates complete recovery of the cored Holocene-middle Miocene sedimentary section at Site 1134.
The primary lithologic parameters used to create the composite section were the 400-nm color reflectance data, a ratio of the 700- to 400-nm color reflectance data measured on split cores, and gamma-ray attenuation (GRA) bulk density data collected by the multisensor track (MST) on whole-round cores (Fig. F9). Natural gamma radiation (NGR) emissions measured by the MST exhibited low values with little variation and were, therefore, not used for composite section construction. For specifics regarding data collection procedures and parameters, see "Physical Properties".
The composite section for Site 1134 is presented in Figure F9. The primary difficulty encountered in the construction of this composite section was the presence of several thick slumped intervals within the upper Miocene and Pliocene section.
The sediments comprising the composite section are of Holocene-early Miocene age, based upon biostratigraphic data (see "Biostratigraphy"). The stratigraphic record within the range of the composite section is divided into three primary lithostratigraphic units (Fig. F9; see "Lithostratigraphy"). The upper unit, lithostratigraphic Unit I (0-33 mbsf, 0-34.7 mcd), is defined by the presence of calcareous nannofossil ooze that alternates between a wackestone and packstone texture. The color reflectance data record the lithologic variations as well-defined, high-amplitude (20%-40%) oscillations with a wavelength of 1-2 m that are easily correlated between holes. The lithologic variations are not as clearly defined in the GRA density data.
Lithostratigraphic Unit II is late Miocene-Pliocene in age and occurs from 33-66 mbsf (34.7-68.9 mcd). This unit is characterized by two slumped intervals at 35-43.3 mcd and 51.2-67.4 mcd (Fig. F9). The top of each slump is easily correlated between holes based upon a dramatic excursion to low color reflectance values and high 700:400 nm reflectance values. The slumps are also characterized by a slight plateau and a more constant signal in GRA density data. The base of each slump is easily recognized and correlated, based upon an abrupt return to the more typical, high-amplitude oscillations in the record.
Lithostratigraphic Unit III is middle-late Miocene in age and occurs from 66 to 152 mbsf (68.9-158.3 mcd). This unit is defined by the presence of calcareous nannofossil ooze, alternating between wackestone and packstone texture and exhibiting variable degrees of lithification. This unit exhibits relatively high reflectance values (60%-80%), with oscillations over very short wavelengths (<0.5 m) and fewer long wavelength features. The 700:400 nm data show a nearly constant record within this unit. Overall, the record within lithostratigraphic Unit III is relatively dissimilar between holes, making correlations more difficult. This may be the result of differential lithification and diagenesis.
The composite and spliced sections indicate that the entire section from 0 to 151.7 mcd was recovered at Site 1134 (Figs. F9, F10). However, correlations between ~100 and 130 mcd are difficult and yield poor correlation coefficients. As a result, Cores 182-1134A-13H and 14H were appended to the splice rather than tied (Table T4, also in ASCII format). Below 152 mcd, core recovery was greatly diminished because of the presence of chert horizons, and core overlap was negligible.