SVlll 
MANGANESE DEPOSITS OS INDIA. 
Chapteb XIV. — concluded. Page. 
The More Complete Metamorphism of the Dharwars . 288 
Primary manganese-ores formed by the metamor- 
phism of manganese-oxide sediments . . 288 
Formation of the manganese silicates, spessartite 
and rhodonite, in the ore -bodies . . . 289 
Liberation of w ater, oxygen, and rarely of carbon 
dioxide 291 
Formation of manganese silicates at the peripher- 
ies of deposits ...... 292 
The banded structure of the ore -bodies . . 292 
Apatite 293 
The Alteration of the ilanganiferous Silicates , . . 293 
Re-conversion of spessartite and rhodonite into 
oxi lized ores (deep secondary ores) . . 293 
Time of alteration of t! e manganese sihcates . 294 
Method of alter;' tion of the manganese silicates . 295 
Mineral Veins ?nd Tntrusives ..... 29o 
Percolation of mineralized w aters during the meta- 
morphism of the ore-bodies .... 296 
Veins traversing the ore -bodies . . . 296 
Rocks intrusive in the ore -bodies . . . 296 
Manganese- ores in Crystalline Limestones . . . 297 
Dharwars in the Chhindwara district . . . 298 
Origin of the quartz-pyroxene-gneisses and crys- 
talline limestones ..... 298 
Origin of the manganiferous limestones . . 300 
Piedmontite-gneisses ..... 301 
Theory of formation of the manganiferous lime- 
stones ....... 301 
Formation of piedmontite, spessartite and rhodo- 
nite 302 
Nodules of manganese-ore and piedmontite . -302 
Alteration of manganiferous limestones . . 303 
Secondary formation of pyrolusite . . . 303 
JIanganiferous cherts ..... 303 
The mineral composition of the manganese-ores . 303 
Folding and faulting of the manganese-ore bands 304 
Classification of the Manganese-ores associated with 
ti o Dliarwar Series ...... 304 
Chapter XV.— The Gondite Series. 
General 306 
Origin of the name ..... .'iCS 
