MANGANESE ORES OF THE CARTERSVILLE DISTRICT, GEORGIA." 
By C. W. Hayes. 
Closely associated with the Georgia deposits of iron ore (see pages 
233-242) are extensive deposits of manganese. These have been 
quite fully described b}' Dr. Penrose, 6 and require only brief mention 
here. All the iron ore contains traces of manganese, but the main 
deposits of the latter ore are quite distinct from the iron. The ore 
occurs, like the brown hematite, embedded in a heavy mantle of 
residual clay, associated with chert and angular fragments of quartz- 
ite. The proportion of clay to ore is usually larger than in the 
deposits of brown hematite. The ore occurs as small concretions 
scattered through the clay, and also in the form of veins, penetrating 
the clay in an irregular manner. It has the appearance of having 
been deposited by solutions percolating through the residual mantle. 
The original source of the manganese was probably the Beaver lime- 
stone, although some of it may have come from the Weisner quartz- 
ite. The deposits occur with about equal frequency in the residual 
material derived from the two formations. 
Dr. Penrose holds the view that some at least of these deposits 
existed in their present form in the rocks of the region before weather- 
ing, and are therefore strictly residual. While this may be true in a 
few cases, the writer has found no evidence of it in the field; and the 
manganese ores are regarded, like the iron ores with which the} 7 are 
associated, as purely secondary deposits, their distribution being 
determined chiefly by chemical and physical conditions, rather than 
by the outcrop of beds especially rich in manganese. 
Although, in the aggregate, a large amount of ore has been mined 
from this district, most of the work has been done in a primitive and 
inefficient manner. It is probable that with modern appliances a 
large amount of material would pay for working which does not con- 
tain a sufficiently large proportion of ore to be profitably worked by 
the present methods. 
"Abstracted from the descriptive text of the Gartersville folio of the Geologic Atlas of the 
United States, in preparation. 
b Penrose. R A. F., jr., Manganese, its uses, ores, and deposits: Ann. Rept. Geol. Survey 
Arkansas, Vol. I, 1890, pp. 418-426. 
232 
