Alt. IX.] Watson, Manganese Ore- Deposits of Georgia. 165 



rived from the two formations. The decay of the Weisner 

 quartzite is a gray to yellow siliceous clay admixed with 

 fragments of the quartzite in all stages of decay ; that of the 

 Beaver limestone is a deep-red clay, less siliceous than that de- 

 rived from the Weisner formation, admixed with some chert- 

 fragments ; and, near its eastern margin in contact with the 

 Weisner quartzite, additional fragments of the latter rock are 

 found. 



The ore is distributed through the clays in an extremely 

 irregular manner in the form of pockets or lenticular masses, 

 rarely as distinct beds ; veins and stringers cutting the clays in 

 all directions ; as single nodules or concretionary masses assem- 

 bled in the clays ; and as small disseminated grains scattered 

 through the clay. In places, the ore-distribution in the clays 

 conforms in a general way to the bedding of the inclosing clays ; 

 usually, however, this is obscured and the ore-bodies indiscrim- 

 inately cut in all directions. The pockets vary widely in size 

 and number. They range in size from mere nests to bodies 6 

 and more ft. thick and more than 30 ft. long, and in extreme 

 cases may yield several hundred tons of ore. Rarely are they 

 composed of solid ore free from the surrounding clay, the usual 

 form being that of somewhat thickly-studded nodules in the 

 clays. They may occur close together, or far apart, and are 

 usually not in any way connected ; although in many cases ir- 

 regular stringers and small veins are observed to lead from one 

 pocket to another. (See Figs. 6 and 7.) 



The ores are never entirely free from inclusions and admix- 

 tures of the inclosing clays, a condition which naturally results 

 from their method of accumulation. Some of the ores are, of 

 course, freer from these mechanical impurities than others, and 

 in the purest ore the included grains of silica and the adhering 

 clay are reduced to a minimum. The proportion of clay to ore 

 is usually larger than in the closely associated brown iron-ores. 



Depth of the Residual Decay. — The depth of the rock- 

 decay varies greatly, and it is dependant, other things being 

 equal, on the character and composition of the rock, and on 

 the disposition of the rock-strata. The quartzite of the Car 



