242 
MANGANESE DEPOSITS OF INDIA : GEOLOGY. [ ParT ll : 
it seems to have been previously overlooked that everything black in the 
khondaUtes is not graphite. In several cases where I have tested Uttle 
black spots and areas in these rocks, they have turned out to be manganese 
oxide. One such occurrence near Sandapuram in the Vizagapatam dis- 
trict is noted on page 1115. Near KaUkot in Ganjam little veins and 
patches of psUomelane are common in an accumulation of boulders of 
khondalite (see page 1037) ; whilst among some specimens of;^khondalite 
sent as examples of building stone from Orissa, there were two from 
Khigerimudia, 3 miles south of Jatni near Khurda Road Station, Puri 
district, showing spots and streaks up to 1| inches long of soft black 
manganese oxide giving a brownish black streak. 
In none of these cases is the manganese oxide, as such, an original 
constituent of the rock ; it has always been deposited in its present form 
subsequent to the formation of the rock. According to the analysis shown 
by Walker^ , khondalite does not contain manganese ; but one may 
suspect that this rock, like most of the ancient crystallines, contains at 
least a small amount of this element, and that during the action of the 
weathering processes on those portions of the khondalites lying near the 
surface the manganese is dissolved out by circulating waters, and re-depo- 
sited where the conditions are suitable, this re-deposition being accom- 
panied by a metasomatic replacement of the rock. Some of this 
manganese oxide, however, has probably been derived from rocks other 
than those of the khondaUte series, such as the manganese-intrusives 
(kodurite series) of Vizagapatam. ji^ 
I Mem. Geol Surv. Ind., XXXII, pt. 3, page 9, (1902). 
