xvi 
MANGANESE DEPOSITS OF INDIA. 
Page. 
Chapter XII.— The Kodurite Series of Vizagapatam and 
Ganjam. 
Vizagapatam district ...... 213 
The Calcareous or calc-gneisses .... 243 
The kodurite series. ..... 244 
Relations of the kodurite series to the other 
crystallines ...... 244 
The kodurite series of igneous origin . . . 247 
Nomenclature of the kodurite series . . . 249 
Pegmatite and vein quartz .... 250 
Minerals of the kodurite series .... 250 
Quartz ....... 251 
Felspar 251 
Apatite ....... 251 
Spandite ....... 251 
Manganese-pyroxenes ..... 252 
Biotite 252 
Graphite ....... 252 
Sphene 252 
Manganmagnetite ..... 253 
Petrology of the kodurite series . . . 253 
Magmatic differentiation of the series . . 254 
Localities for rocks of the series . . . 254 
Ganjam district ....... 255 
Chemical composition of kodurite .... 256 
Chapter XIII.— The Kodurite Series— concluded. 
The Alteration of the Kodurite Series and the Forma- 
tion of Manganese-ores ..... 262 
The replacement of quartz .... 263 
The alteration of the felspar .... 263 
The formation of chert and opal . . . 263 
Potash removed in solution as carbonate . . 264 
Alteration and replacement of apatite . . 264 
Replacement of spandite. .... 265 
Alteration of spandite ..... 265 
Formation of manganese-ores by replacement of 
the kodui'ite rocks ..... 2fl6 
Replacement of tho non-manganiferous varieties. 206 
Minerals replaced by manganese-ore . . . 267 
The removal of alumina ..... 268 
Replacement of the manganiferous varieties . 268 
