Art. IX.] Watson, Manganese Ore Deposits of Georgia. i8i 



ture of the region, the distribution, occurrence and nature of 

 the ores preclude any connection or relationship to these lines 

 of breakage. The region is, furthermore, one of extensive and 

 closely associated ore-deposits of different mineral types, and 

 each type is of considerable commercial importance. These 

 have been separately and independently studied by different 

 geologists in recent years, and while the deposits are closely 

 associated, they have been shown to bear no genetic relation- 

 ship to each other. It is necessary here to make clearer this 

 association of deposits. 



The more important associated deposits consist of brown 

 iron-ore, yellow ocher and bauxite. The deposits of iron-ore 

 all contain traces of manganese, and most of the manganese 

 contains traces of iron, but the principal deposits of the two 

 metals are quite distinct from each other. According to origin 

 several distinct types of limonite or brown iron-ore occur in 

 association with the manganese in the Paleozoic area, grouped 

 by Hayes ^ as (i) Gossan-ores; (2) Tertiary gravel-ores ; (3) 

 Concentration-deposits ; and (4) Fault-deposits. Other forms 

 of iron-ores occur, but they are of less importance within the 

 immediate manganese districts. Only the concentration and 

 fault-deposits concern the discussion of the genesis of the man- 

 ganese accumulation. 



Hayes refers to the concentration-deposits of the Carters- 

 ville district as follows : ^ 



"At various times these valleys [limestone] have received the 

 drainage not only from the adjacent quartzite and limestone, but prob- 

 ably, also, from other of the valley formations ; and the widely dissem- 

 inated iron leached from these formations during the process of decay 

 has been transported to the limestone valley, and there concentrated 

 upon the underlying impervious quartzite." 



The principle underlying the genesis of the concentration- 

 deposits is well expressed in the following sentence by Hayes : ^ 

 "They may occur wherever a limestone is underlain by an in- 



1 Trans., xxx., p. 411 (1901). 



2 Ibid., pp. 412-413. 



3 Ibid., p. 412. 



