(Table 2) Ice rafted debris abundance and accumulation rate, sedimentation rate and dry bulk density of bottom sediments from the Sea of Okhotsk

Oxygen isotope records, radiocarbon AMS data, carbonate and opal stratigraphy, sediment magnetic susceptibility, tephrachronology, and paleontological results were used to obtain detailed sediment stratigraphy and an age model for the studied cores. For studying sea-ice sedimentation an analysis of lithogenic grain number in >0.15 mm grain size fraction of bottom sediments was carried out. For quantitative estimation of intensity ice-rafting debris sedimentation number of IRD particles per sq cm per ka was calculated. Obtained results allowed to plot IRD AR distribution for the first oxygen isotope stage (0-12.5 14C ka, 14C) and for the second stage (12.5-24 14C ka). The first stage was subdivided into the latest deglaciation and the beginning of Holocene (6-12.5 14C ka) (transitive period), when the sea level was changing significantly, and the second part of Holocene (0-6 14C ka), when climate conditions and the sea level were similar to modern estimates. Data clearly show strong increase in ice formation in the glacial Sea of Okhotsk and its extent in the middle part of the sea. Average annual duration of ice coverage during glaciation was longer than that for interglaciation. However the sea ice cover was not continuous all the year round and disappeared in summer time except the far northwestern part of the sea.

(Table 1) Compressional-wave velocities and anisotropies and wet-bulk densities of calcareous rocks and some cherts at DSDP Holes 62-463 and 62-465A

Anisotropy in compressional-wave velocities in sedimentary rocks recovered by DSDP has been recognized by several investigators (Boyce, 1976; Tucholke et al., 1976; Carlson and Christensen, 1977). The anisotropy is also observed at elevated pressures in laboratory experiments, and thus probably persists at depth in some calcareous rocks (Schreiber et al., 1972; Christensen et al., 1973; Carlson and Christensen, 1979). Carlson and Christensen (1979) suggested that the observed velocity anisotropy was produced not by the alignment of cracks but by the alignment of c axes of calcite perpendicular to bedding during compaction, diagenesis, and recrystallization. On DSDP Leg 62, calcareous rocks were recovered from the western Mid-Pacific Mountains (sub-bottom depths of 452-823 m, Site 463) and southern Hess Rise (276-412 m, Site 465). Most of the calcareous rocks are horizontally laminated and color-banded, and ages are early Cenomanian to late Barremian (Site 463 and 465 reports, this volume). The purpose of this study is to confirm the velocity anisotropy in the calcareous rocks and to identify any relationship of anistropy to bulk density, mean velocity, and burial depth.