148 Bulletin of Laboratoncs of Dniison University. [Voi. xii 



Manganiferous iron-ores, - - - - 167 



Analyses of Cartersville iron- and manganese-ores, - 168 



Chemical composition, - - - - - 168 



Individual properties, .... jgg 



The Cave Spring district,- ... . i6g, 



Topography, ..... 169 



Stratigraphy, - - - - - - 171 



Structure, ....... 172 



Character of the residual decay, - - - 173; 



Manganiferous chert-breccia, - - - ■ ' 73 



Manganiferous stained chert, ..... ly^ 



Occurrence of the ores, .... ij^ 



Associated ore-deposits, - - - " '75 



Chemical composition, - - - - - 17^ 



Analysis of manganese ore. Cave Spring district, - - 175 



Olher manganese deposits of the Paleozoic group, - - 175; 



The Lindale deposit, - - - . 176 



The Tunnel Hill district, - - - - - - 178 



Origin of the manganese ores in the Paleozoic area, - - - iSo- 



(,i). Soisrce of the manganese, - - - 183 



(2). Solution, transportation and precipitation of tlie manganese, 185 



(3). Local accumulation of the manganese, - - 186 



II. Manganese deposits of the crystalline area, - - - 189 



Rocks of the crystalline area, - - - - 190 



The rock-forming minerals of the crystalline area, . - - 190 



Residual decay of the crystalline rocks, - - - 191 



Mode of occurrence of the manganese ores, - - - 191 



Mineralogical forms of the ores, - - - 193 



Extent of the work and location of the deposits, - - 194 



Genesis of the ores in the crystalline area, - - - 194 



Methods of mining the ore, - - - - - - 196 



Preparation of the ore, ...... 197 



Introduction. 



A part of the field-seasons of 1900, 1901 and 1902 was 

 devoted by the writer to a study of the manganese ore-deposits 

 of Georgia. A report embodying the results of this study is 

 rapidly nearing completion, and when finished it will be pub- 

 lished as a bulletin of the Geological Survey of Georgia. I 

 believe, however, the importance of these deposits warrants a 

 separate and earlier publication than that made possible by the 

 Survey, in which the more important results of the study are 

 briefly set forth. It is principally for this reason that the pres- 

 ent paper has been prepared. 



