Powderized rock material 462 from each sample (produced in the laminar flow hood on the JOIDES Resolution using a sterile mortar and pestle) was immediately transferred to sterile, muffled glass containers and stored in a desiccator until analysis of carbon and nitrogen according to established methods. Briefly, samples were weighed into methanol rinsed silver boats (4 x 6 mm, Costech). 96-well glass plates (combusted 4 hrs at 450°C) holding these samples were placed in a vacuum desiccator that also contained an open dish with about 50 mL fresh, concentrated (12N) HCl. An inverted crystallization dish was placed over the samplesto protect them from water condensation. The desiccator was closed and pumped out with an airdriven aspirator, to a reading of about ~ 0.5 atm and the desiccator was placed in an oven kept between 60 and 65 °C. Acidification was allowed to run for 60 to 72 hours. When acidification was complete, the samples were removed and set in the oven to dry (60-65 °C), and then placed in a vacuum desiccator charged with indicating silica gel (Fisher S162-500, activated by heating above 220 °C for several hours) and pumped down again and dried for about 24 hours.