98 UNIVERSITY OF MISSOURI STUDIES 



They consist of very pure barite. In Madison County, they ap- 

 pear to be near a zone of faulting. 



Many minor deposits are found in Pennsylvania, New York, 

 New Jersey, Maryland, and various other eastern states. It is 

 well known that the lead, zinc, and flourite deposits of western 

 Kentucky and southern Illinois contain barite. In some mines it 

 is found in considerable quantities, altho this district produces 

 little barite. These deposits are associated with igneous rocks, 

 but the genetic relation of the deposits to the igneous rocks is not 

 generally conceded. The deposits in central Kentucky are in 

 veins which are inclined to the bedding of the formations. The 

 veins are strong, tho found irregularly in the Ordovician lime- 

 stone. They are lean in a .shaly member. Fluorite, galena, and 

 sphalerite are the associated minerals. 



H. S. Poole and C. H. Warren have described important ba- 

 rite deposits at Five Islands, Nova Scotia, and at Lake Ainslie, 

 the latter having been worked since 1890. The Five Islands de- 

 posit is along a fault breccia and forms a large well-marked vein. 

 The fault zone lies along the contact of a syenite and some folded 

 Devonian slates and quartzites. The Lake Ainslie deposits are in 

 several parallel veins cutting Pre-Cambrian felsite. They are 

 quite persistent altho irregular along the strike, and they range 

 from 7 to 10 feet in width. Poole suggests that the igneous rocks 

 may have furnished the material. 



The western part of the United States has several minor de- 

 posits of barite. One of the largest is near Wrangell, Alaska. 

 Others are in California, Arizona, Idaho (10 miles northwest of 

 Hailey), and Clark, Elko, Mineral, and Nye Counties, Nevada. 

 The deposit near Wrangell, Alaska, is described by Burchard.^ 

 It is essentially an island about 75 feet wide and 250 feet long. 

 The deposit is found in schists of various kinds. According to 

 Hill^ a deposit of barite and witherite (the latter being in the 

 deeper parts of the mine) has recently been opened near El Por- 

 tal, Mariposa County, California. It appears as veins in sedi- 

 mentary rocks for at least a mile east of the main mass of intru- 

 sive granitic rock. This suggests a genetic relationship with the 



'Burchard, E. F., Bull. 592, U. S. G. S., pp. 109-117. 1914. 

 'Hill, J. M., Min. Res. U. S., pt. 2, p. 64. 1914. 



