(Table 1) d18O of interstitial waters at DSDP Sites 87-582, 87-583, and 87-584

In the present paper, we report preliminary results on the 18O/16O ratios of the interstitial waters of the DSDP cores taken from subduction-related trenches near Japan: Sites 582 and 583 at the Nankai Trough off southwestern Japan, and Site 584 at the Japan Trench off northern Honshu, where thick piles of young sediments have accumulated. Special attention was paid to any differences in isotopic behavior of interstitial waters with different surrounding lithoiogy, the details of isotopic variation of interstitial waters in young, unconsolidated sediments, and the effects of sedimentary structural disturbance on interstitial waters.