Interstitial Water studies on small core samples, deep sea drilling project, leg XII

With the exception of Site 114, all interstitial waters in Leg 12 showed marked increases in calcium, which can be attributed to diagenetic dissolution and recrystallization of calcium carbonate, especially coccolith and foraminiferal tests. Magnesium loss may be due to either or both replacement of iron in clays or the dolomitization of calcium carbonate. The lowest sample from Site 113, on the mid-Labrador Sea Ridge, yielded only 250 mg/kg magnesium but 2.56 g/kg calcium in interstitial water from a clayey, siliceous quartz silt. Strontium values close to and exceeding 100 mg/kg were noted, especially in sites showing extensive carbonate recrystallization. Few significant deviations in chloride concentration from sea water levels were noted.