(Appendix A) Helium isotope concentrations and ratios for leached replicates of sediments from ODP Hole 130-806B

To maximize the size of the samples analyzed, aliquots of 2 to 3 g were leached in 10% acetic acid for 6 h to remove CaCO3. This resulted in residues of about 250 mg of noncarbonate material, which were suitable for handling in the gas extraction system. Samples were then rinsed in distilled water, centrifuged to isolate the residue, ovendried at 60°C overnight, and wrapped in tin foil ready for loading into the Caltech Noble Gas Laboratory all-metal gas extraction system. Comparison between 2 to 3 g leached and 0.5 g unleached (bulk) aliquots of the same sample shows that helium in the samples is not affected by acetic acid leaching.