194 



COOKE 



C0 2 AND N 2 



TRIGGERING CONNECTION 



TO 

 ATMOSPHERE 



RECORDER 



Fig. 2 Analysis system. 



approximately 80 miles north of Bermuda. Artificial seawater and ion-deficient 

 seawater were also used (Lyman and Fleming ). 



Total C0 2 in seawater, both before and after exposure to calcite in the 

 reactor, was determined by taking the seawater from the pressure vessel through 

 alternate valving (Fig. 1). Once background total C0 2 was measured in seawater 

 not in contact with the calcite, the total C0 2 in calcite-exposed seawater was 

 determined at a number of pressures. Information in the figures is presented in 

 terms of concentration of total C0 2 in exposed seawater vs. pressure. The total 

 C0 2 concentrations in the exposed seawater, relative to the unexposed seawater, 

 is indicative of precipitation, dissolution, or steady state within the calcite— 

 seawater system. These three processes were all observed and were functions of 

 pressure and composition. 



In the first experiment, seawater of 35.5% salinity and pH of 7.985, with 

 total C0 2 of 2.247 millimoles/liter, was passed through the calcite column in the 

 system described in the preceding paragraph. At moderate pressures (10 to 334 

 atm), precipitation took place upon the calcite surfaces within the column, and 

 the total C0 2 of the effluent seawater was diminished by removal of carbonates 

 from solution. The schematic recorder trace for this process is shown in Fig. 3. 

 In Fig. 3, seawater is passing through the reactor after having laid down a 



