The pore fluid samples analyzed in this research are either splits from the samples analyzed on board and reported in Salisbury, Shinohara, Richter, et al. (2002) and Mottl et al. (2003) or residues from the onboard hydraulic conductivity tests of Hart and Hammon (2002). The former were collected from 3-cm-long sample splits from whole-round serpentinite mud-containing cores. The experiments were conducted using the same apparatus and techniques as the routine onboard pore fluid sample collection. The analyzed rock samples are serpentinized peridotite clasts and muds collected aboard the JOIDES Resolution during ODP Legs 125 (Site 779: Conical Seamount) and 195 (Site 1200A: South Chamorro Seamount). For detailed descriptions of the clasts and muds see Salisbury, Shinohara, Richter, et al. (2002), Fryer (this volume), Savov et al. (this volume), and Savov (2004).
Iodine and bromide concentrations in mud, ultramafic clasts, and pore fluids were determined using inductively coupled plasma–mass spectrometry (ICP-MS) at the Japanese Institute for Nuclear and Radiological Sciences. Prior to analysis, the mud and clast samples were washed and the halides were extracted using hydropyrolysis and collected in a solution of 2% tetramethylammonium hydroxide (Schnetger and Muramatsu, 1996). Extractions were carried out three times in order to assure reproducibility, and both Cs and Rh were added as primary and secondary internal standards.
The boron abundances of the serpentinized peridotite clasts and muds were measured by direct-current plasma emission spectrometry (DCP-ES) at the University of South Florida (Tampa, Florida, USA) after Na2CO3 flux fusion in Pt crucibles and followed by standard additions (Ryan and Langmuir, 1993). Uncertainties strongly depend on the concentrations but are ±5% for the majority of the samples. Boron measurements were always reproducible, based on monitoring by replicates of the certified U.S. Geological Survey (USGS) and Geological Survey of Japan (GSJ) standards DTS-1, BIR-1, BHVO-1, JP-1, and JB-3. Pore fluid boron concentrations were measured using a JY2000 inductively coupled plasma–atomic emission spectrometer (ICP-AES) aboard the JOIDES Resolution following procedures described in Mottl (1992) and Mottl et al. (2003).