12 UNIVERSITY OF MISSOURI STUDIES 



rapid erosion. Where erosion is rapid, the quartz is at the sur- 

 face, and not infrequently barite is abundant there also. This is 

 especially true of the outlying areas where barite is just begin- 

 ning to be produced. The soils of the Potosi are fertile and are 

 tilled wherever the topographic position of the land permits. 



Proctor soil. — There is practically no difference in color 

 between the Proctor and the Potosi soils. As the Proctor dolo- 

 mite contains very little chert, its soils are relatively free from 

 it, unless they contain some which is residual from the overlying 

 Gasconade dolomite and sandstone. The Proctor dolomite is less 

 resistant to weathering than the other formations and forms gen- 

 tle benches on the less steep slopes. The soils are very fertile, 

 and are tilled over most of the area where the Proctor formation 

 is found. Since the soil derived from the Proctor formation is 

 usually free from chert it is tilled on the crest of a hill or on the 

 sides. 



Soils from the Gasconade and Rouhidoux Formations. — The 

 soils from these formations are gray and black at the surface but 

 below they are yellow and brown where the other for- 

 mations are red. Almost without exception these soils are full 

 of chert, sandstone, or quartzite. The exceptions are the occasi- 

 onal flat areas on the crest of the ridges. Here the soils are 

 sometimes relatively free from chert and are of an ash-gray 

 color. They are generally only a foot or eighteen inches thick. 

 With sufficient rain they make very good soils. Since there is 

 much sandstone in these formations, the soils from them are 

 largely sandy loams. Pines are numerous on such soils. 



Wind-blown soils 



It has been mentioned above that all the soils, especially 

 those on the crests of the ridges, may have an ash-gray color. 

 This color is rarely more than a few inches thick and gives way 

 to a clay loam below. Examination with a microscope shows 

 that the particles are more or less rounded altho they are very 

 fine. Since they are found especially upon the crests of the 

 ridges it is believed that the material is largely wind-blown. 



