62 DOMESTIC WATER SUPPLIES FOR THE FARM 



The materials include clays, sands, gravels, marls and a few 

 more or less solid limestones, the latter being present mainly in 

 the southern states. A few of the sandy layers have been con- 

 solidated and now form sandstones. The beds dip gently toward 

 the coast. The waters in the North occur mainly in sands and 

 gravels, especially in those at the base of the Coastal Plain de- 

 posits. Farther south, particularly in the Gulf States, water is 

 found both in sands and in the porous limestones. The quality of 

 the water in the gravels in the northern portion of the belt is 

 generally soft and good, but farther south, notably where sands 

 and gravels alternate with clay or limestone beds, the waters are 

 often hard or are charged with sulphur and iron. The capacity 

 of the wells is generally large and many of them flow without 

 pumping. In the aggregate, there are several thousand deep wells 

 scattered throughout the Coastal Plain. They are used principally 

 for domestic and farm supplies, but some of them that yield soft 

 waters are utilized for industrial purposes. In the Gulf States, 

 especially in Louisiana, a large number of wells furnish water for 

 the irrigation of rice. A considerable number are also used as 

 sources of public water supplies. 



The Piedmont Plateau. - - The Piedmont Plateau proper con- 

 sists of a belt of crystalline rocks, including a few small basins of 

 Triassic sandstones, that extends southward from southeastern 

 New York along the east front of the Appalachian Mountains to 

 Alabama, lying between the mountains and the Coastal Plain. 

 Where the plateau joins the Coastal Plain its elevation is only a 

 few hundred feet, but the altitude of its surface increases gradu- 

 ally toward the northwest, until at the base of the mountains, 

 especially in western North Carolina and vicinity, its highest 

 points have altitudes of several thousand feet. In the main its 

 surface, where uncut by streams, is flat or gently rolling, but 

 in its higher portions it has been cut into a series of prominent 

 mountains. In the vicinity of the streams near the coast it is 

 also cut into a series of lower hills, as in the case of the Coastal 

 Plain. 



