Leg 185 revisited and redefined an ODP legacy site on the western Pacific plate. Hole 801C is now a reference site for a number of key physical and chemical features of the planet, most notably for the birth and structure of the Pacific plate, the variation of the magnetic field in the Jurassic, and the bulk geochemical composition of oceanic crust. For the latter, the crust not only acts as a sink for major and trace elements in global fluxes between seawater and the continents but also as an important part of the input into the subduction factory for key chemical components. When subducted, these elements play a key role in the global fluxes of the planet through mobilization during subduction metamorphism and melting and final recycling into the mantle. Leg 185 also permitted the quantification of sediment input into the subduction system along a north-south transect where the components show an extreme variation, largely controlled by the wide range in paleoenvironments traversed by the plate. These different sediment inputs are recorded in the outputs of nearby volcanoes and also in components that will be recycled into the mantle and may be sampled later in Earth's history by mantle melting and magmatism.