84 UxNIVERSITY OF MISSOURI STUDIES 



Since the actual circulation of the water is confined to these 

 openings, the solvent power of the water is restricted to the sides 

 of the passages, a greatly limited amount of rock as contrasted 

 with that ordinarily assumed to be affected in such considera- 

 tions. That this is actually the case is proved, as rock absolutely 

 fresh and unaltered is found to within a fraction of an inch of 

 the joint. Even at the surface where solutions have their great- 

 est opportunity of attacking and penetrating the rock they rarely 

 penetrate it for more than a quarter of an inch. The dolomite 

 under the clay in the barite pits is disaggregated to a depth of a 

 few inches at the most. Many instances were noted where sul- 

 fides occurred adjacent to the joints, yet were wholly unaltered. 



When the actively circulating waters above ground water 

 level are unable to penetrate and alter the rocks more than a frac- 

 tion of an inch, the slowly moving waters below ground water 

 level will certainly attack them much less. The movement is so 

 slight that the small vugs are usually without water in them, even 

 above ground water level where the circulation is fastest. 



It does not seem that ground waters are adequate to concen- 

 trate such small traces of barium salts as might exist, since they 

 are able to reach only the portions of the rock adjacent to the 

 joints. Also the above analyses show that the rocks in this vici- 

 nity contain almost no barium. 



Deposition of the barite. — If the barium is transported in 

 solution as the sulfate there is no need to seek for a source of 

 the sulfate. This is an improbable means of transportation, how- 

 ever, as ground waters have little power of transporting barium 

 sulfate. 



It is more likely that the barium is carried as the carbonate 

 or the chloride, probably the latter, as is shown by the analyses 

 above. If it is transported as the carbonate it was probably al- 

 ready in existence in that form. In any case it becomes neces- 

 sary to account for a sulfate radical in the vein solutions. If the 

 vein contains a sulfate radical, it would react with some barium 

 salt, if present, and produce barite. Or, it might be assumed, 

 that the oxidation which produced the limonite so commonly 

 found with the barite formed the sulfate radical which united 

 with the barium. But, since the barite was deposited on the 



