ECONOMICAL GEOLOGY. 185 
Alumina, 
2.51 
12.75 
8.4S 
Oxide of Iron, 
4.99 
8.S7 
17.49 
Oxide of Manganese, 
0.70 
Lime, 
.... 0.04 
4.37 
0.08 
Magnesia, 
.... 0.07 
1.33 
0.76 
Potash, 
0.07 
0.72 
0.10 
Soda, 
1.52 
0.10 
Phosphoric Acid, 
.... 0.09 
0.15 
trace. 
Sulphuric Acid, . 
.... trace. 
trace. 
0.00 
Chlorine, 
trace. 
0.22 
Organic Matter, 
.... 3.10 
3.95 
8.00 
Water, . . . 
.... 0.90 
2.00 
2.40 
The first of these specimens is from Leasbnrg, on the west border of Per- 
son county. It is an ash-colored, gravelly soil, overlying hornblendic and 
feldspathic rocks at the depth of a few feet. The growth is thickety, and 
composed of small blackjacks, post oaks and hickories. Plaster and salt 
would supply the most obvious defects, and doubtless much increase its 
productiveness, which is naturally low. Number 54 is from a gladey, 
blackjack flat, ten miles southeast of Charlotte, Mecklenburg county. 
The soil is a light gray, gravelly loam. The growth is almost exclusively 
blackjack, with an occasional post oak. The underlying rock of this region 
is syenyteand doleryte. It is evidently a very fine and durable soil, need- 
ing only thorough draining to develop its fertility. 
There is a large area of land of similar quality and origin to these two 
samples, overlying the amphibolic and syenytic rocks of the Greensboro 
and Charlotte belt of granitic rocks. The surface is generally quite flat, 
or but slightly undulating. The color is generally light to slightly yel- 
lowish gray, and sometimes dark gray and greenish, and in composition, 
the soils are generally a very gravelly clay, pasty and boggy in wet 
weather. 
Number 55 is from a flattish, gladey, blackjack woods, in the southern 
part of Granville county, three miles south of Taylor’s Bridge. The soil 
is derived from a coarse, dark trap (doleryte) dyke of several hundred 
yards breadth. There are some oaks among the growth, of which black- 
jack is the most characteristic. 
Soils of the Piedmont and Mountain Sections. 
56 57 58 59 
Silica, Insoluble, 76.88 71.64 54.87 77.06 
“ Soluble, 0.67 0.00 0.78 3.84 
