78 UNIVERSITY OF MISSOURI STUDIES 



suits. These are the only instances that could be found where 

 barium has been shown to occur in limestones or carbonate rocks. 

 Winslow^ gives the following analyses, made by J. D. Rob- 

 ertson : 



Magnesion limestones (Cambrian) 

 Locality Percentage of BaSOi 



1. Pettis County, near Smithton 0017 



2. Pettis County, near Smithton 0020 



3. St. Francois County, Desloge Mine 0040 



4. St. Francois County, Desloge Mine 0050 



5. St. Francois County, railway tunnel, Valle Mines. . .0011 



Average 00246 



Lower Carboniferous limestones 



7. Jasper County, Carthage quarry 0022 



8. Jasper County, Carthage quarry 0020 



9. Jasper County, Joplin, bluff on Turkey Creek 0047 



10. Jasper County, Joplin, bluff on Turkey Creek 0049 



11. Jasper County, Webb City, near Sucker Flats 0037 



12. Jasper County, Webb City, near Sucker Flats 0049 



13. Lawrence County, one-half mile south of Aurora. . .0012 



14. Lawrence County, one-half mile south of Aurora. . . .0008 



15. Pettis County, Sedalia quarry trace 



These analyses, all having less than .005 per cent BaSO^, 



show how small an amount of this substance occurs in some of 

 the limestones and dolomites of Missouri. 



In order to determine whether there was any barium in the 

 Potosi, Proctor, or Gasconade formations of the Washington 

 County district, very careful qualitative tests were made of these 

 formations and not a trace of barium was found. This is con- 

 firmatory of many other analyses made for this purpose. It also 

 indicates that the source of the barium in the Missouri deposits 

 must be looked for outside of the surface rocks of the region. 



A limestone, described by Ransome,^ from the Rico district, 

 Colorado, shows a trace of BaO. Smith^ reports .02 per cent 

 BaO in the St. Louis limestone from the northern part of Crit- 



"Winslow, Arthur, Mo. Geol. Sur., vol. 7, pp. 4S0-481. 1894. 

 'Ransome, F. L., 22d Ann. Rept., U. S. G. S., Pt. 2, p. 283. 

 'Smith, W. S. T., op. cit. 



