Figure 15. Depth profile for silica in Site 1001 interstitial waters. The stratigraphic position of a major unconformity (see text and Sigurdsson, Leckie, Acton, et al., 1997, for details) and the basaltic basement are indicated. Ash (as discrete layers) and chert distributions are also included. The arrow indicates mean ocean bottom-water silica concentration. The two symbols (open and solid) used in the silica profile reflect the incorporation of data from two holes at Site 1001.