16 MINERAL RESOURCES OF ALABAMA. 



' field furnaces from the numerous banks about Russellville : 

 Metallic iron 53.67 per cent; Alumina 5.58 per cent; Silica 

 8.52 per cent.; Phosphorus, 0.33 per cent. It is said 

 to work well in the furnace and to yield an unusually good 

 quality of pig iron, that seldom runs higher than 0.60 per cent 

 of phosphorus and 0.50 per cent of silicon. 



The Lauderdale Chert: The ore of this formation is in 

 stratified seams and pockets. The former are probably the 

 weathered outcrops of carbonate and the pocket ore also, in part 

 at least, from the weathering and breaking down of the strati- 

 fied seams. 



The stratified ore in one or two seams may in some localities 

 be traced for miles where it is too thin or too cherty to be of 

 commercial value. At intervals along these outcrops there are 

 some extensive deposits of boulder, nodular and gravelly ore 

 of good quality, though as a rule inferior to the limonites of 

 some of the other formations. It has never been extensively 

 worked in Alabama. Some of the limonites of this formation 

 are highly manganiferous. 



The Knox Dolomite : The brown ore of the Knox Dolo- 

 mite is the most abundant, has been extensively mined and, in 

 general, is the best of the iron ores of the state. Some of the 

 deposits have been worked to depth of 100 feet wkh ore still 

 at the bottom. 



The most important deposits and mines are in Cherokee, 

 Calhoun, Talladega, Shelby, Bibb, Tuscaloosa and Blount 

 counties. The ore is found in irregular pockets in the red 

 clay resulting from the decomposition of the limestone of the 

 formation, and while mostly of good quality, high in iron and 

 low in silica and phosphorus, it is sometimes rough and cherty 

 and sometimes a black waxy ore, high in phosphorus. The 

 cherty ore is usually in large boulders, sometimes occurring in 

 rows as if outcrops of stratified ledges. 



The view in Plate II of an open cut at Greeley in Tusca- 

 loosa county, illustrates well the mode of occurrence and 

 method of mining the brown ore. 



The average composition of the dried ore, as shown by many 

 analyses is, Metallic iron 51.00 per cent; Silica 9 per cent; 

 Alumina 3.75 per cent; Lime 0.75 per cent; Phosphorus 0.40 

 per cent, and Sulphur o.io per cent. 



