Twenty-two whole-round
samples were taken for interstitial water analysis from Holes 996A (seven
samples), 996D (six samples), and 996E (nine samples). The interstitial waters
were extracted using the procedure and equipment described by Manheim and Sayles
(1974). Eight samples of meltwater from dissociation experiments on massive
pieces of hydrates were collected for analysis from Holes 996B (two samples of
the same hydrate nodule), 996C (three samples of which two were taken from the
same nodule), 996D (two samples), and 996E (one sample). Interstitial water and
hydrate meltwater were analyzed for Cl- (precision 0.2%) according to
the methods described in ODP
Technical Note 15 (Gieskes et al., 1991). The 
2H
values (reproducibility ± 0.5
)
were determined at Institute for Energy Technology (Kjeller, Norway) by
reduction over Zn at 900șC and analysis of H2 by a Finnigan MAT
Delta E Isotope Ratio Mass Spectrometer. Values are reported relative to the
standard mean ocean water (SMOW) scale.
