PHASE PHENOMENA IN CALCITE-SEAWATER SYSTEM 203 



9. W. H. Berger, Foraminiferal Ooze: Solution at Depths. Science, 156: 383-385 (1967). 



10. W. H. Berger, Diversity of Planktonic Foraminitera in Deep-Sea Sediments, Sciences 

 (N. Y.), 168: 1345-1347(1970). 



11. W. H. Berger, Sedimentation of Planktonic Foraminifera, Mar. Geol., 11: 325-358 

 (1971). 



12. W. H. Berger, Planktonic Foraminifera: Selective Solution and Paleoclimatic Interpreta- 

 tion, Deep-Sea Res., 15: 31-43 (1968). 



13. R. C. Cooke, The Lysocline and Calcium Carbonate Compensation Depth in the Sea, 

 Ph. D. Thesis, Dalhousie University, August 1971. 



14. M. N. A. Peterson, Science, 154: 1542-1544 (1966). 



15. J. Lyman and R. H. Fleming, J. Mar. Res., 3: 134-146 (1940). 



DISCUSSION BY ATTENDEES 



Kilham: I have studied the magnesium and strontium contents of deep-sea 

 bivalve mollusks from 1000 to 5000 m in the Atlantic. Generally, I found that 

 the amount of magnesium in the shells decreased with increasing depth. The 

 same was also true of strontium. It is important to note that all the shells were 

 aragonitic. 



Cooke: Strontium is taken up in aragonite to a greater extent than it 

 is in calcite— magnesium taken up in calcite. I did experiments on strontium and 

 found no discernible result by changing strontium in a calcite system. Obviously, 

 the number of experiments that would follow this sort of thing are legion, but 

 aragonite has to be looked at as well. It may be that much the same thing exists 

 in that case — on the other hand, if there is no inclusion or incorporation of an 

 atom in the lattice of aragonite which raises its solubility, then the lysocline for 

 aragonite would perhaps have a completely different source. 



