Calcium carbonate concentrations in Early Miocene sediments from ODP Hole 145-884B in the subpolar North Pacific

We measured calcium carbonate concentrations in sediment samples from ODP Site 145-884. Mass percents of calcium carbonate were measured using a CM5014 CO2 coulometer. Between 3 and 15 mg of dry, pulverized sediment were added to capsules, which were acidified using 4 N sulfuric acid. The mass of inorganic carbon was measured after 8 minutes. Pure calcium carbonate standards and blanks were run every 8 and 19 samples, respectively, for quality control. Blank-corrected sample masses of inorganic carbon were converted to masses of calcium carbonate, and then this was divided by the mass of dry sediment analyzed to calculate calcium carbonate concentrations. Sample replicates and pure calcium carbonate standards indicate measurement precision within 1% calcium carbonate.