6 
Magnetite, an oxide of iron, is a common mineral of our soils, and is 
of value in furnishing iron to plants. 
Quartz is by far the most predominant mineral existing in most of 
the soils of North Carolina, the only exception being those of the Ire¬ 
dell Series. In this series quartz is subordinate to epidote and horn¬ 
blende. Much information can be obtained by a close observation of 
the quartz fragments as to the conditions through which a soil has 
passed. These fragments are often rounded, showing that erosion has 
taken place and that they have been subjected to great leaching. Especi¬ 
ally is this true of the soils of the Coastal Plain. 
In many of the Coastal Plain soils, especially those of the Ports¬ 
mouth series, an abundance of animal remains, phytolitharien, sponge 
spicules, or rhizopoda casts are found. The presence of these animal 
remains indicate that at some previous time these soils were covered 
with water. This may be responsible for the low state of productivity 
of these soils. 
Invariably the silt separates contain a larger amount of plant food 
bearing minerals than do the sands, and in the Piedmont and Mountain 
sections these minerals have suffered greater decomposition than those 
in the sands. Often the silt separates from the Coastal Plain 3 oils 
present pure clean faces, as though little alteration had taken place. 
As quartz is the most abundant mineral found in these soils, and 
as it has no plant food value so far as is known, in the mineralogical 
examinations, the author has done as McCaughey and Pry did; compared 
the other minerals to quartz, and knowing no better way to show the 
mineralogical composition, have tabulated these analyses after their 
fashion. 
Mountain Soils. 
Classification .— The soils of the Mountain section are somewhat 
analagous to those of the Piedmont Plateau, but in all cases they have 
been considered as belonging to separate series. All the upland soils 
encountered so far in the detail soil survey have been considered as 
belonging to the one broad series known as Porter’s. The various 
types of this series have been formed from schists, gniesses, and gran¬ 
ites. The individual types are more dissimilar, perhaps, than is com¬ 
monly the case, but it has not seemed possible to form a new series m 
any of the areas so far surveyed. With the extension of the survey to 
other counties, it is possible that representative types of other soil 
series will be formed. There is little doubt, however, that the great 
bulk of the upland falls within the present limits of the Porter’s series. 
The two extensive upland soils are loam and sandy loam, while three 
other types are represented by smaller areas. These are the clay, sand, 
and black loam. 
The valley and bottom land soils are included in the Toxaway series. 
These are of alluvial origin, modified by colluvial wash, and have been 
formed from washing of the Porter’s series, and deposited by streams. 
The surface of these soils is flat, or level, with a gradual slope toward the 
streams. They lie at sufficient elevations above the normal water level 
of the streams so as to be fairly easily drained. However, most of these 
soils are subject to frequent overflow. The two types thus far found 
are the Toxaway loam and Toxaway fine sandy loam. 
