J 92 
GEOLOGY OF NORTH CAROLINA. 
Magnesia, 0.50 0.58 1.07 1.39 1.42 trace 
Potash, 1.28 0.85 0.25 1.06 0.79 1.34 
Soda, 0.36 0.00 0.05 0.00 0.46 
Phosphoric Acid, 0.35 trace 0.34 0.10 0.39 0.44 
Sulphuric Acid, 0.49 0.18 0.0S 0.20 0.24 0.75 
Carbonic Acid, 40.61 40.29 42.33 39.35 32.46 20.96 
Water and Org. Mat., 0.16 0.26 0.46 0.45 0.52 2.98 
The first four specimens are from New Hanover county ; number 8 
from a point about a mile N. E. of Wilmington, the locality called Hard 
Scrabble; the others from Rocky Point and vicinity; 9 from D. T. Dur- 
ham’s place, one mile west of R. Pt., the marl lying so near the surface 
as to be exposed in the ditches and even the furroughs of the wide river 
fiats, which extend from the North East River at Rocky Point for nearly 
a mile in this direction and several miles along the course of the river ; 
No. 10 from a plantation known as Green Hill, some 2 miles above R. 
Point, in a situation cpiite similar to the last ; Mosely Hall, the next plan- 
tation above, furnishing sample 11. These marls are all of the same de- 
scription, viz, white, rather coarse, friable, shell and coral sandstone, easily 
removed with a pick, or even a hoe. The only point south of the Cape 
Fear where I have seen this formation is the bluff of Black Rock. 
Here it is quite similar to that just described, but it is only a few inches 
thick apparently, and lies in immediate contact with the greensand of 
that bluff. It is found however all along the course of North East River 
and the other streams north of Wilmington, and every where within a 
few feet of the surface. At the Davis place. 7 miles above the city on 
the N. E. River, as well as at Rocky Point, the formation occurs both in 
the form just described and as a compact limestone, which is valuable 
both for building purposes and as- a source of lime, for which it was largely 
used during the war : it has also served as a flux for iron smelting. 
It will be seen that these samples, which are representative for the 
region of the Cape Fear, have a chemical constitution not different from 
that of ordinary limestones, the percentage of carbonate of lime ranging 
from about 90 to 95. Of the same character are the outcrops along the 
North East River and its head waters through Duplin and (the eastern 
side of) Sampson counties, as for example, on Maxwell’s Creek, near the 
bridge at Chinquepin, at Mr. Jcs. Shines, some 7 miles east of Mt. Olive 
Depot, and at Mr. Henry’s in Young Swamp near Faison’s Depot. The 
outcrop near Kenansville, at Rev. Mr. Stallings’ differs from the preced- 
ing only in its somewhat lower percentage of carbonate of lime ; it is 
represented by No. 12. No. 13 is from Dr. Roberts’, near Mt. Olive, and 
