THE BARITE DEPOSITS OF MISSOURI 5 



County but includes a few square miles of St. Francois County 

 to the east. The total area of the district covered by the geologi- 

 cal map is about 230 square miles, about 50 square miles of 

 which had been mapped before the writer began his work. The 

 area includes all of townships 37 N., R. 2 and 3 E. ; 38 N., R. 2 

 and 3 E. ; 39 N., R. 3 E. ; the southern part of T. 40 N., R. 2 E. ; 

 and a small part of T. 40 N., R. 3 E. ; nearly half of T. 39 N., 

 R. 3 E. ; the southwest sections of T. 39 N., R. 4 E., and the 

 northwest corner of T. 39 N., R. 4 E. The entire area lies north- 

 west of the St. Francois Mountains and upon the Ozark Plateau. 

 It is some eight or ten miles to the nearest peaks of the moun- 

 tains from the southern border of the district. 



The Central district includes parts of Moniteau, Morgan, 

 Camden, Miller and Cole counties in the central part of the state 

 south of the Missouri River. The deposits are scattered over 

 these counties, probably the most important ones being in Mor- 

 gan, Miller, and Cole counties. The geography and geology of 

 this district will be discussed separately. 



TOPOGRAPHY 



Relief. — The Washington County district lies on a plateau 

 in which streams have developed a mature topography. The 

 highest points are in the southern part of the area, where several 

 of the ridges rise to an elevation of about 1,250 feet. East of the 

 ridge west of Hopewell and Summit, on the Iron Mountain Rail- 

 road, higher parts of the surface have a common elevation of 

 about 1,000 feet. North of the high ridge, referred to above, the 

 surface declines to about 1,100 feet west, northwest, and north 

 of Potosi. The ridge between Mine a Breton Creek and Amaux 

 Creek reaches 1,100 feet and the highest point at the northern 

 side of the area is 1,050 feet. This indicates that the surface 

 was originally a plain sloping to the north ; and into it the streams 

 have cut their valleys to depths of from 100 to 300 feet, the 

 deeper valleys being those of the major streams to the north. 



The lowest point of the area is a little less than 550 feet 

 above sea level. This is on Big River where it flows out of the 

 barite area. This is also the point where Mineral Fork, the 

 largest stream entirely within the area, enters Big River. This 



