(Table 1) Relative change in the thermal conductivity of ODP Hole 128-799B

Thermal conductivity of soft and hard sedimentary materials recovered from Hole 799B drilled during Ocean Drilling Program (ODP) Leg 128 in the Japan Sea was measured under hydrostatic pressures up to 100 MPa at room temperature. In sedimentary materials, the dependence of the thermal conductivity on pressure varies from sample to sample. Sediment fabrics and water content, as well as porosity, seem to be key factors controlling the pressure dependence, although we cannot definitely identify yet which of them is the most important factor for determining this property. Ratcliffe's estimate of pressure correction (1960) seems to be valid on average. In view of the small effect of pressure on the thermal conductivity within pressure ranges of this study, the heat flow values obtained so far from this area of the Japan Sea do not need to be corrected significantly.