26 GEOLOGICAL 6UBVEY OF ALABAMA. 



are shown in its structure and surrounding. Its true posi- 

 tion is not free from doubt. 



In the Cloivdus Gap in S. 13 the structure is yet more 

 complicated. From the northwestern side of the Lower 

 Conglomerate, measured southeastward, at right angle with 

 the strike, to the first known vertical coal seam, the dis- 

 tance is 545 feet, and thence to southeastern side of vertical 

 rocks 450 feet, making whole thickness of vertical strata 995 

 feet. The highly inclined strata dipping S. E. gives the 

 following 



SECTION : 



(1) From southeast side of vertical rocks to first known 



coal seam 50 feet. 



(2) COAL, thin and irregular 3 to 12 inches. 



(3) Slate, dark blue. .32 feet. 



(4) COAL, thin seam 3 to 4 inches. 



(5) Slate, light blue to grey 300 feet. 



(6) COAL, good, bright, hard, cokes well 1 to 3 feet. 



(7) Slate, gray, and hard brownish gray sandstone . 50 feet. 



(8) COAL, hard, brittle, cubical, (Saw Mill seam) . 22 inches. 



(9) Slate, hard light blue to gray 60 feet. 



It is evident from inspection of this section, that no point 

 of identity with similarly located sections farther to the 

 southwest, either in coal seams or strata, can be clearly per- 

 ceived. It may be that seam No. (6) is the equivalent of the 

 Waide, or Cowden Seam ; but it carries much better coal, 

 and is crushed and distorted to such a degree that its iden- 

 tity could only be a matter of inference. 



The bed-rock of seam No. (8) alone, of all the strata seen 

 in this section, bears a strong resemblance to the bed-rock 

 of the Cowden Seam. But in all other particulars the two 

 seams are wholly dissimilar. 



That a fault, or slip in the strata, of unknown extent, ex- 

 ists in this gap, is evident from seams above No. (6) of the 

 last section, not bearing the same relation to it, or to each 



