Chemical Composition of Interstitial Waters from Marine Sediments, Baffin Bay

Abstract

ABSTRACT Seven cores from deep water were taken along a transect following the northwest-southeast axis of Baffin Bay between Greenland and the Canadian Archipelago. The sediments in the cores consist of sandy and silty muds. Pore water was squeezed from the sediments and analyzed for chlorinity, sulfate, calcium, magnesium, sodium, potassium, strontium, rubidium, and lithium. Chlorinity and sulfate in the interstitial waters are similar to those of Copenhagen seawater. Apparently bacterial reduction of sulfates in pore waters does not occur. The Ca/Cl ratio in interstitial waters decreases slightly relative to Copenhagen seawater, whereas the trend for the Mg/Cl ratio is one of increase. Increase in magnesium is considered to be related to its release by chlorite, which is abundant in the Bar in Bay sediments. Values for the Na/Cl and K/Cl ratios in the interstitial waters cluster about those for Copenhagen seawater. The ST/Cl ratio of interstitial waters tends to decrease relative to Copenhagen seawater, although in the pore waters of some cores this ratio overlaps with and even increases relative to Copenhagen seawater. The Rb/Cl ratio is higher in interstitial water than in normal seawater. The expected parallelism between the changes in the K/Cl and Rb/Cl ratios is not apparent. Despite some exceptions, the Li/Cl ratio in interstitial waters increases relative to seawater. Many of the changes in the cation/Cl ratios reported in this paper differ from those of other studies of interstitial waters and cannot be explained by simple cation exchange.