The purpose of ODP Leg 185 is to sample old Pacific crust and sediments in order to better estimate geochemical fluxes during subduction of old, altered crust.  Two sites, BON-8A and ODP Site 801 will be drilled.  Previous work has involved study of alteration effects in basement (Alt et al., 1992) and geochemistry of sulfur in sediments and pore waters (Alt and Burdett, 1992), as well as sulfur in Mariana Arc volcanics (Alt et al., 1993).