A specific goal at this site was to evaluate the areal extent of the continental lithosphere component that has been recognized in the Leg 119 Site 738 lavas using trace element and isotope geochemistry. Sedimentary objectives at this site were to determine sequence facies, to define the ages of seismic sequence boundaries, to estimate the duration of possible subaerial and shallow marine environments, and to obtain minimum estimates for basement age. As discussed below, the 128.1 m of sediment and 33.3 m of basement penetration will enable us to achieve most of our objectives. Although this basement penetration was much less than the planned 150 m, a result of an unexpectedly slow drilling rate, a significant unanticipated bonus was the recovery of Albian and Late Cretaceous nannoplankton, foraminifera, and pollen assemblages that will provide information on paleoceanographic conditions during those times. Disturbance by drilling concentrated the coarse material, and the nature of sediment composing this unit is uncertain.
Some intervals contain partially cemented sediments.
Minor amounts of clay and quartz are present and silt-size palagonitized basaltic glass shards cause the brown color. The ooze contains abundant inoceramid prisms, sponge spicules, and ostracods in addition to common foraminifers and nannofossils. Beginning at 128.1 mbsf, Hole 1136A penetrated three basaltic lava flows, which are designated Units 1 through 3. No definitive evidence favors a subaerial or submarine emplacement for these flows. However, we recovered 6.22 m of the massive interior and base of the flow.