22 GEOLOGICAL SURVEY OF ALABAMA. 
to the left, in the valley, on the left the divide between the 
head waters of Shades creek and a prong of the Cahaba 
river is soon passed, Trussville may be seen to the left 
from a point on the mountain abouta mile southwest of the 
gap where Cahaba river penetrates Rocky Ridge. Hick- 
man’s Mill is on the river, a short distance up stream, and 
Revis’s Grist Mill down stream from this gap. Our boun- 
dary line continues along Rocky Ridge, following the same 
direction (the measures having a rate of dip to the south- 
east of about nine degrees), until arriving at a point one 
and a quarter miles south of Springville, where the Rocky 
Ridge with its accompanying Millstone Grit changes its 
direction and bears to the southeast, the Springville prong 
of Canoe creek following close along its foot at the north- 
east side. Opposite to Truss’ Mill, on Canoe creek, it will 
be noticed that the Millstone Grit became vertical and the 
direction of the boundary of the basin and Coal Field 
changes and bears from this point due south, merging into 
the great southeastern boundary fault at a point about 
one and a half miles north of Odenville. The boundary oi 
the basin and Coal Field then continues along ’Possum Val- 
ley, passing close by the DeBardeleben Coal & Iron Com- 
pany’s office and store at Henryellen, keeping along the 
valley north-west of the high cherty ridge known as Ander- 
son Mountain, Pine Ridge and Mill Ridge, for a distance of 
twenty-six miles, to what is known as Bragg’s school-house 
or Methodist church. 
The southwest boundary of the basin extends from this 
point northwest across the Cadaba Coal Field, intersecting 
Cahaba river about a mile in a straight line above Caldwell’s 
mill, thence continuing on to the Millstone grit on the north- 
west side of the basin at a point due southeast from Birm- 
ingham and about four or five miles distant. 
There are about six public and settlement roads crossing 
this basin, along which nearly all the rocks of our Canaba 
Coal Measures can be examined, except the great 500 feet 
conglomerate that overlies the Montevallo seam; though 
a part of this conglomerate can be seen on the Birmingham 
and Columbiana road near DeLoach & Company’s grist 
mill. One of the roads leaves the Birmingham and Spring- 
