27 O FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT. 
and the heavier members for growing cotton? corn, and other gen¬ 
eral farm crops. In Florida certain of the types are used in growing 
citrus fruits. The sandy members predominate. 
NORFOLK sand. 
The Norfolk sand consists of a gray or slightly brownish gray 
loose sand, underlain at about 5 to 8 inches by a gray, grayish-yellow 
or pale-yellow incoherent sand extending to a depth of 3 feet or 
more. In the lower part of the 3-foot section the material usually 
has a lighter color than the upper subsoil, especially in the lower 
lying, poorer drained situations. 
In the lower situations, where the Norfolk sand grades into the 
Portsmouth soils, the surface soil is darker in color, usually a dark 
gray to grayish brown. The texture of the Norfolk sand varies 
somewhat. In places quartz fragments of the size of buckshot are 
encountered. In other places the type contains large quantities of 
fine sand. 
The type occurs on slight elevations within bodies of Portsmouth 
soils. The largest areas are in the southern part of the county be¬ 
tween the Santa Fe and New Rivers, and on the higher elevations 
above the Santa Fe River near Worthington. One area is developed 
in the northeastern part of the county near Highland, on the ele¬ 
vation which forms the divide between the Gulf of Mexico and the 
Atlantic Ocean. 
The Norfolk sand was originally forested with longleaf pine, 
live oak, water oak, blackjack oak, and turkey oak. It supports a 
scant growth of wire grass. 
Very little of the type is under cultivation. It is so 1 thoroughly 
drained that crops are likely to suffer from drought even during 
ordinary periods of dry weather. The nature of the soil is such 
that with continuous cultivation the supply of organic matter be¬ 
comes depleted unless special care is taken to maintain the supply 
by plowing under green crops frequently. The incorporation of 
humus in the soil increases its water-holding capacity and renders 
it less susceptible to drought. As a whole the type is easily handled. 
It can usually be plowed within a few hours after a heavy rain. It 
is adapted to early truck crops, but is used locally for the general 
farm crops. 
