ECONOMICAL GEOLOGY. 
J 95 
represented by a line parallel to and 3 or 1 miles west of the Wilmington 
and Weldon Railroad, from Halifax to Goldsboro. Southward, the inland 
boundary is found to be generally but little west of a line connecting the 
latter point and Lnmberton, that is, a line parallel to the coast and about 
65 miles distant from it. 
The area included within the above limits is about one-fourth of the 
state, — a much larger territory than the whole state of Massachusetts, or 
New Jersey. 
These beds, even along the western boundary, are seldom found at an 
elevation exceeding 100 feet above the sea. 
The analyses given below, of specimens gathered from the whole region, 
will give the means of judging of the value of these deposits, and of their 
importance to the agricultural development of a large section of the 
state. 
Blue Marls South of the Gape Fear. 
21 22 23 2d 25 26 27 
Silica, 6.97 61.61 18.S1 53.25 25.28 39.36. 5.65 
Ox. oflron and Alumina, 0.86 2,80 2.72 11.28 3.02 3.17 3.30 
Lime, 17.62 19.60 11.48 13.19 37.52 2S.96 18.51 
Magnesia, 1.03 0.12 0.16 1.96' 
Potash, 0.37 0.56 0.22 0.75 0.23 
Soda, 0T5 0.09 0.25 0.17 0.30 
Phosphoric Acid, 0.19 0.18 0.10 0.11 trace. 
Sulphuric Acid, 0.11 0.06 0.61 0.10 0.18 0.31 
Carbonic Acid, 38.15 15.37 32.07 10.59 29.02 22.73 39.80 
Org. Matter and Water, 1.25 3.12 2.9S 1.11 0.60 
No. 21 is from a point in Robeson county, 3 miles north of Lumber- 
ton, — farm of 13. Godwin. It is a gray earthy mass, with many shells, 
in every stage of decay, most of them small. It is very rich in lime, and 
has several other valuable ingredients. The proportion of sand is 
unusually small. It has been used with excellent effect on the farm. 
The bed is within three feet of the surface. Similar beds are reported 
3 miles northwest of this point, and on Lumber River 1 to 2 miles above 
and below Lnmberton, and 10 miles south, on Hog Swamp. No. 22 is 
found near Whiteville, Columbus county, half a mile south, in the slight 
acclivity just across the swamp. It is composed largely of comminuted 
shells, and is brown in color. The materials have evidently been dis- 
turbed since their deposition, and the bed in consequence conforms 
