44 GEOLOGIOAL SURVEY OF ALABAMA. 
ellen basin. The’Cambrian measures on the southeast side 
are the same as those surrounding the southeast side of the 
Henryellen basin. 
The Acton basin is due south from Birmingham; a line 
from the Union depot, Birmingham, running due south, 
would cross the top of Red Mountain at a distance of two 
miles, and intersect the first seam of the basin (the Brock 
seam) at a distance of five miles; said line continued due 
south would reach the southeast boundary of the Acton 
basin at W. Y. Jones’ place in Possum Valley, at a distance 
from the Union depot of eleven and a half miles. This due 
south line would follow very close, almost parallel with the 
public road that leaves Cahaba Valley at Bishop’s Mill, 
crossing Cahaba river at Bain’s Ford and leads to Birming- 
ham. 
For relative positions of the seams of this basin, see the 
Acton Horizontal Section from “G” to “H,” and the South 
and North Railroad Vertical Sections, both on the accom- 
panying map. The prominent rocks exposed in this basin 
are very similar to those described in the Henryellen basin. 
Commencing at the Millstone Grit on the northwest side of 
Shades Mountain and ascending in the measures by going 
southeast, you will find an immense ledge of the Millstone 
Grit, forming all the upper part of the top of the mountain 
and all the southeast side of Shades Mountain. After 
passing over this, you will find a thick bed of gritty slate 
with a thin seam imbedded in it, occupying the valley be- 
tween Shades Mountain and Pine Ridge. The next ridge 
(or Pine Ridge) southeast of Shades Mountain has a heavy 
ledge of the white sandstone of the Milistone Grit forma- 
tion, for a cap rock or shield; this also underlies the soil on 
the southeast side. Descending Pine Ridge on the south- 
east side you will arrive at the immense beds of gritty slate 
that underlies the Gould seam. After passing over the 
Gould seam you arrive at the large bed of gritty slate and 
slaty sandstone that overlies the Gould seam; these gritty 
slates occupy almost the whole of the Gould Valley, except- 
ing a few thin ledges of pink and red sandstones. On the 
southeast side of this valley is Red or Chestnut Ridge ; this 
is capped with the upper layer of the white sandstone of 
