Ammonia (NH 4 ) 



Ammonia can come directly from sea water, nitrates, nitrites, and organic 

 material. Ammonia may come from petroleum after its formation. 



Lithium (Li) 



Lithium, like N0 2 and N0 3 , has been rarely determined; however, some 

 connate waters have been found to contain abnormally high concentrations of this 

 element. 



Magnesium (Mg) 



Magnesium, like calcium, has some decidedly variable values, but they far 

 from attain those of calcium. Some magnesium salts have a greater solubility 

 than those of calcium. Only in very few waters has the concentration of mag- 

 nesium been found to exceed that of calcium. One water of the Permian Basin 

 of West Texas, contained 3 grams per liter of calcium and 34 grams per liter 

 of magnesium. Calcium and magnesium are not found in some waters, which 

 are generally waters of weak concentration and meteoric waters that have 

 penetrated the beds and, in doing so, have undergone a reduction of SO4 or an 

 exchange of bases. 



Calcium (Ca) 



The calcium content of connate waters is variable. The calcium has its 

 origin essentially by dissolution of certain sedimentary rocks, particuarly of 

 limestone, dolomite, gypsum, anhydrite, and marlstone. Sandstones contribute 

 only through their cementing material; and the crystalline rocks contribute only 

 small quantities. The calcium content can be increased by the exchange of 

 bases, or it can be decreased by the reduction of S0 4 or by the exchange of bases 

 of calcium against sodium at which point the content of calcium can fall to zero. 



Strontium (Sr) 



Some connate waters contain high concentrations of strontium, but, con- 

 versely, some do not contain any, or very little. Because strontium is a com- 

 panion of calcium, limestones may be rich in strontium. Waters with the highest 

 calcium content, as a rule, are the richest in strontium. However, it is the SO4 

 ion and the free C0 2 in the water that determines the amount of the element 

 that can remain in solution. 



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