A total of 335 interstitial water samples were gathered from 13 sites during Leg 175 (Table 1). The sampling protocol was developed to ensure essentially complete coverage of the stratigraphy at each site, and, with a few exceptions, we were able to obtain our deepest sample very near the total depth of penetration at each site (Table 1). Because of end-of-leg time constraints, the database from Site 1087 was not completed; consequently, a discussion of the chemistry at this site is not included here.
As described in the "Explanatory Notes" chapter and the individual site chapters (all this volume), the sampling frequency occurred in two main modes: (1) standard sampling of one sample per core for the uppermost 100 meters below sea floor (mbsf) and then every third core to the total depth of the hole and (2) at three sites (Table 1), ultra-high-resolution sampling at a frequency of one sample per section of core for the uppermost 60 mbsf, below which the standard sampling protocol was followed. These acquisition strategies ensured that we are able to address the early-, mid-, and late-stage diagenetic processes occurring at the various depths at a given site.
At each site, we generated a data set that included pH, alkalinity, Ca2+, Mg2+, K+, Na+ (by charge balance), SO42–, Cl–, H4SiO4, PO43–, NH4+, and Sr2+. Because of the extremely high core recovery during Leg 175 and the multitude of extra sites drilled, we were not able to utilize the shipboard atomic absorption facility for analyses other than for dissolved Sr2+. Analytical methods are described in the "Explanatory Notes" chapter (this volume) as well as by Gieskes et al. (1991). Postcruise analyses will specifically target trace metal (iron, manganese, barium, and others) and isotopic (δ18O, δ13C, 87Sr/86Sr) distributions to further expand this data set.