62 GEOLOGICAL SURVEY OF ALABAMA. 
neglected and out of common use. Said wagon road crosses 
the Cahaba river at the Lacey Ford, passing under the high 
railroad trestle in section 5, crossing Shades mountain at 
Brock’s Gap, thence on by Oxmoor to Elyton and Birming- 
ham. On the top of Shades mountain, two other roads 
branch from this, one going southwest on the top of the 
mountain towards Gurnee and Blocton, the other one takes 
a northeast course on the top of Shades mountain and leads 
to the Morrow orchard, Howell orchard, the Earnest vine- 
yard and the Hale place. Both these last mentioned roads 
follow along close to the edge of the basin, the roads being 
but a short distance above the base of the Millstone Grit. 
The length of this basin is about three and a half miles 
from the southwest end to the northeast end, by an average 
width of two miles, and it contains an area of seven square 
miles. The amount of good, workable coal in it, in seams 
over two feet in thickness, amounts to 23,000,000 tons (of 
2,000 pounds), at a depth of not. over 2,200 feet; in this 
computation there is no allowance for loss in pillars or 
waste in mining ; about three-fourths of the above 23,000,- 
000 tons are very good coking coals, furnished by the Gould, 
and Cahaba or Wadsworth seams. 
The Cahaba basin is drained by the Cahaba river and its 
tributaries, Buck creek, Bailey’s branch, Black creek, Mar- 
tin’s branch, Lainey branch and others. 
The prominent ridges of this basin are Shades mountain 
on its northwest side, then Pine ridge, near and parallel to 
the last mentioned, and Red or Chestnut ridge, near and 
parallel to the other two. The South and North Alabama 
Railroad Vertical Section, and the Helena Horizontal Section 
on the accompanying map, give the relative positions of the 
seams of this basin; also the form of the basin and its rela- 
tions to the interior fault and the Helena basin. The hori- 
zontal section, showing both basins, is taken along the line 
shown on map from “I” to “J,” said line crossing the South 
and North Alabama Railroad very near the slope of the 
South Birmingham Coal and Iron Company, at Sydenton. 
The rocks of this basin can be seen to the best advantage 
along the South and North Alabama Railroad. Commenc- 
ing at the northwest end of the Brock’s Gap cut, the lower 
