94 UNIVERSITY OF MISSOURI STUDIES 



chalcopyrite are very common. In special types of deposits other 

 minerals occur. A tabulation of 26 Canadian barite deposits 

 showed the following mineral associates. These deposits con- 

 tained essentially the same minerals as listed above but not in the 

 same abundance. 



Occurrence 

 in deposits 



Calcite 10 



Fluorite 6 



Hematite 6 



Galena 3 



Quartz 2 



Copper ores 2 



Pyrite 2 



Sphalerite 1 



There is a marked similarity between the mineralogy of the 

 Missouri deposits and that of the various ore deposits which con- 

 tain the metals. In this connection, the lack of barite in south- 

 eastern Missouri deposits and its rare occurrences in the Joplin 

 area and the Upper Mississippi Valley region are very striking. 



The rocks, in which mineral deposits containing barite as an 

 abundant gangue mineral are found, include all the types of ig- 

 neous, metamorphic, and sedimentary rocks. In the United 

 States igneous rocks predominate in association with those de- 

 posits which contain the most barite as a gangue mineral. 



Similarity to shallow vein deposits. — Lindgren has presented 

 the data of shallow deposits made by ascending thermal waters 

 in genetic connection with igneous rocks in chapter 22 in his 

 "Mineral Deposits." He points out that hot springs are known 

 to deposit barite. He gives several examples, such as the hot 

 springs at Carlsbad and Teplitz. To these may be added the in- 

 teresting radio-active hot spring in Japan that is depositing 

 barium and lead sulfates from a water which contains also free 

 hydrochloric acid.^ Altho not hot springs, those described by 

 Headden^ are interesting because they are radioactive and are 

 depositing a large amount of barite. 



'Yokachiro, Okamoto, Chem. Abstracts, vol. 7, p. 2369, 1913. 

 'Headden, W. P., Proc. Colo. Soc, vol. 8, pp. 1-30. 1905. 



