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 ro4th 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, 
Souci 
