CAHABA COAL FIELD: HELENA BASIN. 53 
ures of the Mammoth split, (b,) from above Henryellen to 
Blocton, wherever the writer has seen these rock layers ex- 
posed. Then passing over an additional seventy-six feet of 
fine grained sandstone brings you to the Blackshale seam ; 
this seam is three to three and a half feet thick, on an aver- 
age, in this basin. This seam is the upper bench of the 
Mammoth seam, and is also the same seam as the Gholson 
seam now being worked by the Excelsior Coal Company at 
the No. 1, No. 2, and No. 3 slopes at Gurnee, on the Brier- 
field, Blocton and Birmingham Railroad. The Blackshale 
and the Buck are the Helena equivalent of the Mammoth at 
Henryellen. The Blackshale is also the same as the Ghol- 
son in the Lolley basin and the Dailey Creek basin. From 
the South and North Railroad to the south end of the field 
this seam and the Buck occupy an almost continuous val- 
ley, along which the engineers. have recentiy located the 
Helena and Blocton branch of the Birmingham Mineral 
Railroad, the Buck or Clark being generally near the bot- 
tom of, or on the northwest side of the valley, while the 
Blackshale or Gholson will generally be found on its south- 
east side, often some distance up the side of the hill. 
While the Blackshale is six feet at Henryellen and is five 
feet thick at the old Gholson mine, the average of it, in this 
basin, as has been proved by actual tests, is not over three 
and a half feet, yet it is a solid seam of good coal, free from 
any interlarded layers of slate, smut, or other injurious 
partings. The following is a measured section of the Black- 
shale, from a test pit near the South and North Railroad: 
[Blackshale seam, in N. E. 14 of N. E. 14 of section 16, township 20, S., 
range 38, W). 
SANDSTONE 
SreEETIINcH Cofl 
\\G Bozrom SLATE 
(b) The word split here refers to the barren strata—sandstones, etc., 
which come in between and separate the two benches of the Mammoth 
6eam, 
