40 GEOLOGICAL SURVEY OF ALABAMA. 



General Section of the Clinton Strata. 



Black Shale. 



Shaly and slaty beds, clay and some iron ore 15 feet. 



Heavy bedded sandstone, sometimes 40 to 50 feet, usually 10 " 



No. 1. Iron bed, ore lenticular or concretionary 2 to 4 " 



Yellow sand rock, soft, gnarly, no cleavage 10 " 



No. 2. Fossiliferous iron ore bed 6 inches to 2> " 



Soft, dark, irony sand rock 7 feet to 15 " 



No. 3. Iron ore bed, varying greatly in quality 2 " 7 " 



Flaggy sandstone, shale and clay 20 " 40 " 



No. 4. Iron ore, hard, rough, pebbly or lenticular 2 " 20 " 



Dark grey sand rock, often massive 20 " 50 " 



No. 5. Iron ore, soft, fine grained, dark ore, often limy . .3 ' 20 " 



Trenton Limestone. 



In addition to the five beds of iron ore presented in the 

 section, there are often several others; but as they are not 

 very persistent, and were .found nowhere thick enough to be 

 of value, or even of good quality, no notice has been taken 

 of them. 



This section only approximates the general structure and 

 arrangement. To present it by accurate measurements from 

 place to place, would require a very great number of sections. 

 These, by their variances, would rather confuse than aid the 

 reader. An average portion of the formation was therefore 

 taken and measured, by which all other portions can be 

 compared. 



The variations in the Clinton are great and numerous ; 

 they embrace all its constituent members^ The rocks vary 

 in thickness and quality, in color and texture. The iron ore 

 beds vary in number, and in quantity and quality of the ore; 

 and these variations take place rapidly. No one mile of this 

 formation is the exact equivalent, or counterpart of any 'other 

 mile. This formation was by the older geologists well named 

 "The Protean Group," because of its want of uniformity and 

 the rapidity of the changes in its strata. 



