238 GEOLOGICAL SURVEY OF NEW JERSEY. 



mixture and consistency, it is an excellent and inexpensive road 

 material. The abundance of such gravel in a country where 

 the natural roads are bad is a fortunate coincidence. When 

 sand and gravel are cemented together by compounds of iron, as 

 is often the case, a durable conglomerate is formed, which is the 

 principal building-stone of the region. 



The sources of the rivers of the Coastal Plain are on its 

 northwestern edge. The land slopes gradually to the sea, and 

 is so level that tide-water penetrates far. into the interior. 

 Drainage is therefore good, and stagnation of standing water 

 only occurs here and there in places which are underlain with 

 an impermeable hardpan. 



The Plains* are extensive, practically treeless regions in the 

 northern part of the Coastal Plain. The region called the East 

 Plains contains 6,662 acres, and the West Plains 7,737 acres. 

 There are other areas of the same nature, so that 20,000 acres 

 is a conservative estimate of the amount of land of this kind. 

 These Plains are hilly, about one hundred feet in height, and 

 with gentle slopes. The surface soil is usually a bleached sand. 

 Often there is a subsoil of clayey loam and gravel at varying 

 depths. Often the subsoil is hard-pan, and in places there are 

 beds of conglomerate and strata of clay. There is practically 

 no physical difference between the soil of the Plains and the 

 soil of thousands of acres in the neighborhood on which trees 

 of good dimensions are growing. Owing to the hilliness of the 

 region in comparison with the surrounding country, and owing 

 to the lack of a more extensive cover, the soil has been subjected 

 to the leaching and beating of rain and the scorching and drying 

 effects of the sun and wind. One would expect to find it, there- 

 fore, exceedingly poor in quality, with a dearth of plant food, 

 which might, at least in part, account for the absence of a more 



*The term "plain" is usually applied to broad stretches of country which are level or undulating. 

 Owing to the fact that vast treeless areas in the West are called " The Plains," treelessness is popularly 

 associated with the word " Plain." For this reason, no doubt, certain treeless regions in New Jersey are 

 called " The Plains," although they are hillier than the surrounding country. Geographers, however, 

 apply the term to level regions regardless of their cover ; for instance, " the Atlantic Coastal Plain." It 

 is worthy of note in this connection that the people of the West distinguish between the " Plains " and 

 " Prairies." The term " Prairies" is applied to the region between the io4th meridian and the eastern 

 base of the Rockies. Their treelessness is mainly due to a lack of moisture. East of this are the 

 " Plains," a fertile but formerly treeless region. The absence of trees is here due rather to the extreme 

 fineness of the soil or to fire and grass than to moisture conditions. Wherever a plain is produced by fire 

 reforestation is possible, but in regions where treelessness is due to a lack of moisture, afforestation is 

 difficult and often impossible without irrigation. 



