COAPIER. I, 
THE HENRYELLEN BASIN. 
The Henryellen basin occupies the north end of the Ca- 
haba Coal Field; it is twenty-eight miles in length by an 
average width of four and a quarter miles, measuring from 
the base of the Millstone grit on the north-west side of 
Rocky Ridge to the great boundary fault in "Possom Valley, 
on the south side of the Cahaba Coal Field. Its greatest 
length is measured from the southwest end of the basin at 
a point about a mile in a straight line south of the mouth 
-of the east fork of the Cahaba river, where it joins the main 
stream, to the northeast boundary of the basin as well as 
‘of the Coal Field, at the Springville prong of Canoe creek. 
This basin contains an area of 119 square miles, and is 
drained solely by the waters of the Cahaba river and its 
tributaries ; chiefly of the east fork of Cahaba river and 
‘the numerous prongs of Black creek. The outcropping of 
the Millstone grit, having a rate of dip of about nine de- 
grees, and forming what is known in this region as Rocky 
Ridge, clearly outlines the northwestern and the north- 
eastern boundary of the basin, as well as the b. undary of 
this portion of the Cahaba Coal Field. The great fault in 
"Possum Valley separating the Cambrian from the Carbon- 
iferous measures, forms its south-eastern boundary. South- 
east of said boundary fault, and running parallel with it, is 
a high, prominent cherty ridge of Silurian age, known near 
the southwest end of the basin as Mill Ridge, near the 
middle portion of the basin as Pine Ridge, and near the 
northeast end of the basin as Anderson Mountain. This 
prominent ridge can be seen from almost any part of the 
high ridges in the basin, guiding the eye to the location of 
the basin (also Coal Field) at its foot. The southwest boun- 
dary of the basin passes through sections 28, 34 and 35, 
township 18, range 2, west, intersecting the Cahaba river at 
