50 UNIVERSITY OF MISSOURI STUDIES 



Barite has been reported also from many of the counties in the 

 northern part of the Ozark Plateau, where it is of mineralogical 

 rather than economic interest. 



Topography. — The district lies on the northern or north- 

 western slope of the Ozark Plateau. This slope, the Salem Plat- 

 form, is now dissected, the greatest relief being along the Osage 

 River, which cuts thru the region from the western to the east- 

 tern side. As a matter of fact the dissection along the Osage 

 River has been the determining factor in exposing the barite de- 

 posits. This is due to the fact that the deposits are confined 

 mainly to the lower geological formations and these have been 

 exposed by the river. 



The topography is mature over most of the district. The 

 streams have not developed flats of match size, not even the 

 largest streams. The higher portions of the region have a rela- 

 tively slight relief and are splendid agricultural lands, but the 

 portions along the Missouri and the Osage Rivers and their 

 larger tributaries are very rough, and not well adapted to agri- 

 culture, although the large part of the acreage is so used. 



Drainage. — The Missouri and the Osage Rivers receive the 

 drainage of the district, the major part going through the Osage, 

 a large navigable stream with an extremely tortuous course. 

 Other large streams are Moniteau and Moreau Creeks that drain 

 into the Missouri, and the Niangua, Anglaize, Gravois, Saline, 

 and Big Tavern Creeks that flow into the Osage. All the large 

 streams are at grade and the small ones have steep gradients 

 which enable them to handle the load of chert and gravel pro- 

 duced by the weathering of the carbonate rocks. The majority 

 of these streams have developed meandering courses. 



GEOLOGY 



The rocks of this district belong to the Cambrian (Proctor), 

 Ordovician (Gasconade, Roubidoux, Jefferson City, and St. 

 Peter), Mississippian (Burlington), and Pennsylvanian systems. 

 The time interval represented by them is long, and much of it is 

 represented by unconformities. The first four formations are 

 regarded as of Cambrian age by some geologists, while others 

 put the Jefferson City formation and part or all of the Gascon- 



