52 



EDWARD M. SHEPARD 



cussion, 20 miles north of Wynne. The land here is frequently too 

 poor to support much vegetation. There is little or no loam, and 

 arid patches of sand are common. Along the edges of the cracks 

 and fault scarps large deposits of sand are frequently found. Another 

 peculiar feature of the country which should be mentioned is the 

 presence of "sand blows" — low mounds of fine white sand mixed 

 with small pieces of lignite. These mounds are 3 or 4 feet high, 

 with a diameter of from 20 to 100 feet, and are frequently slightly 



Fig. 4. — An east-and-west geological section through Memphis, Tenn. Vertical 

 scale exaggerated about 250 times. The Orange Sand (LaFayette formation) lies 

 between the Artesian Sand and the Impervious Blue Clay of the diagram. (From 

 J. M. Safford's report to the Artesian Water Co., of Memphis, Tenn.) 



hollowed in the center. They are scattered over the whole district, 

 and the sand is so pure that it will not support vegetation, and conse- 

 quently barren patches mark their site. 1 



ASSOCIATED ARTESIAN CONDITIONS 



The Mississippi Valley forms a strong artesian basin between 

 the Tennessee Mountains and the Ozarks. Referring to the geo- 

 logical section and map adapted from the report on The City Water 

 Supply 0} Memphis, by Safford, it will be noticed that loess covers 



1 The inhabitants claim that wells driven in these " sand blows " give a better 

 quality of water. 



