THE BARITE DEPOSITS OF MISSOURI 99 



granite. E. L. Jones in the same report describes barite veins 

 with a maximum width of three and one-half feet, 10 miles from 

 Parker, Arizona. They are in basalt flows, tuffs and breccias 

 and in some places in sandstones. The veins are not persistent 

 along the strike and are of no prospective value. They are, howv 

 ever, of interest in the general problem of the origin of barite de- 

 posits. 



This summary of the main features of the barite deposits of 

 this country shows that barite is found in veins, which are more 

 or less persistent and not uncommonly very strong. The vein 

 material is either pure barite, or barite with calcite, fluorite, and 

 various sulfides, chief among which are galena, sphalerite, and 

 pyrite. 



These veins are in many cases associated with faults or fault 

 zones, a condition which suggests that the solutions found egress 

 from below. In other cases, there are replacement deposits in 

 limestone. Igneous rocks exist in the neighborhood of some of 

 these deposits. 



In the Piedmont region of the Appalachians, the barite is 

 wholly in igneous and metamorphic rocks. In these cases, the 

 conclusion that there is a genetic connection between them seems 

 almost unavoidable. Similar deposits are found in the western 

 United States, in some places wholly within the igneous rocks. 

 Furthermore, many ore deposits of igneous origin contain barite 

 as a gangue mineral. 



The important German deposits are wholly in veins which 

 are directly connected with igneous rocks, and are believed by 

 German scientists to have been deposited by magmatic waters. 



From the evidence, it seems to the writer that the formation 

 of many of these deposits is readily explained by assuming that 

 they are directly connected with igneous rocks from which the 

 barite and associated minerals were derived. 



Conclusion as to origin 



Evidence has been presented to show that barium is a widely 

 disseminated element in all kinds of rocks, but that it is far more 

 abundant in igneous than in sedimentary rocks. A discussion of 

 the adequacy of ground water solutions to concentrate and bring 



