30 GEOLOGICAL SURVEY OF ALABAMA. 
half of the basin and empties into the Cahaba River, near 
the Henryellen Company’s No. 3 slope. The southwest 
half of the basin is drained by the Cahaba River and its 
tributaries. In 1883 this basin did not have a single mine 
opened in it on any of its seams. 
The DeBardeleben Coal and Iron Company have three 
slopes sunk on the lower bench of the Mammoth, and are 
now mining coal with the most approved machinery and 
appliances, under the skilful management of Mr. Samuel T. 
Brittle, with Mr. Hugh Howard as superintendent. Two 
railroads, (the Georgia Pacific and the Columbus and West- 
ern, or Central of Georgia), run through the basin to con- 
vey away the coal, and there is a fair prospect of another 
road very soon. The Macon and Birmingham Company, 
now building a railroad along Possum Valley from Gads- 
den to Montevallo, would develop by means of lateral 
roads all the southeast side of the Cahaba Coal Field, and 
would tap more available coal than any railroad in the 
State of the same length. The rocks of the vertical coal 
measures of the boundary fault have the same composition 
and general appearance that they possess in the interior of 
the basin. 
The measures of the Henryellen basin, like all our Ala- 
bama Coal Measures, were evidently at one time approxi- 
mately level, the ferns and peat mosses of that time in the 
lakes and bogs of that day, were then forming the carbon- 
aceous matter for our present coal seams. The split in the 
Mammoth shows that after the first five feet or so of the 
coal had been formed there was a depression of the seam, 
100 feet deep, towards Helena, which became filled up with 
white sand and other materials from external sources a 
after it had filled up to a level with the two ends, then the 
other portion of the Mammoth seam was formed on the 
top of it. 
The present inclined position of the formerly horizontal 
beds of the Henryellen basin is due to the great fault or 
upthrow of 10,000 feet on the south-eastern boundary of 
the basin, and to the upthrow of Jones Valley, which gave 
its present dip to the Millstone Grit and other measures of 
the northwest side of the basin. Some men look at this 
