DISTRIBUTION OF CALCIUM CARBONATE IN PELAGIC SEDIMENTS

Statistical analysis of 1,350 pelagic sediment samples indicates that on a worldwide basis water depth correlates poorly with CaCO3 percentage of sediments. When the data are grouped into 1,000 m intervals, correlations between percent CaCO3 and water depth are not greatly improved. Grouping the data first by latitudinal ranges and then by geographic areas only improves correlations sporadically. When nearshore data are excluded to remove the effects of clastic influx, correlations between percent CaCO3 and depth improve. This exclusion raises the correlation between percent CaCO3 and water depth to-0.620, meaning that water depth, predicts about 40% of the variability in CaCO3 percentage of pelagic sediments. Neither variations in CO2 concentration nor supposed rates of inorganic CaCO3 solution appear to be satisfactory explanations for this moderate correlation between percent CaCO3 in pelagic sediments and water depth. We suggest that adsorbtion of organic molecules to carbonate particles may prevent or inhibit carbonate-sea water interactions. © 1968.