ECONOMICAL GEOLOGY. 
197 
there are many occurrences of such beds, as at Owen’s Hill, — mostly 
oyster shells ; about Elizabethtown, above and below, (a sample from Cro- 
marty’s gave Dr. Emmons 40 per cent, of carbonate of lime); at Brown's 
Creek, and again at Walker’s Bluff, where the marl is nearly 20 feet 
thick, and about 50 feet above the river, and overhanging it. It abounds 
in shells, at one point exclusively oysters (0. mauricensis). Again the 
marl appears at Brown’s Landing, and at D. F. Flower’s, who lias long 
used both this and the greensand marl very successfully. The miocene 
marl on his place is of a brown color, and full of shells. At a point near 
this, some 2 miles from the river, the shells are all oysters (O. mauri- 
censis), and perfectly sound, as at Walker’s Bluff. Shell marl is also 
abundant, and has been profitably used at D. A. Lamont’s, a few miles 
below. In the southern part of Brunswick it is said to be abundant, 
both on the Waccamaw River and between that and the coast, eastward 
of the Green Swamp. 
Blue Marls of New Hanover. 
28 
29 
Silica, 
37.24 
43.21 
Ox. of Iron & Alumina. 
, 2.09 
4.57 
Lime, 
.30.45 
27.50 
Magnesia, 
l.SS 
0.41 
Potash, 
1.60 
0.49 
Soda, 
0.34 
0.00 
Phosphoric Acid, 
0.38 
0.51 
Sulphuric Acid, 
. 1.10 
0.49 
Carbonic Acid, 
.25.16 
21.31 
Org. Mat. and Water,. 
1.51 
30 
31 
32 
33 
34 
49.17 
65.94 
45.17 
25.34 
26.35 
2.98 
4.72 
4.12 
1.61 
5.47 
25.20 
14.32 
25.50 
34.43 
33.03 
0.52 
0.54 
0.57 
0.59 
0.59 
0.45 
0.77 
0.55 
0.66 
0.91 
0.03 
0.46 
0.10 
0.00 
0.02 
0.74 
1.22 
1.33 
0.39 
1.67 
0.32 
2.25 
trace 
1 34 
0.28 
19.50 
9.47 
19.44 
30.53 
24.S9 
1.09 
0.31 
3.22 
0.11 
6.S9 
The larger part of Hew Hanover county contains blue marl, as well as 
deposits of the two preceding and underlying formations. The first of 
the above samples is from the left bank of the Cape Fear at Parsley’s 
mill, about a mile above Wilmington. The bed lies immediately on the 
Greensand, 6 or 8 feet above water. The color is light gray, and shells 
are abundant, and generally small and much decayed. The analysis 
shows a marl of very good quality, with an unusually large percentage of 
potash and magnesia. This marl is very easy of access and probably 
abundant, and would be of great benefit to the sandy soils of the neigh- 
borhood. Hear the Carolina Central depot is another outcrop of the bed, 
the upper part of which is a solidified conglomerate, the shell bed lying 
