394 
MANGANESE DEPOSITS OF INDIA : GEOLOGY. [PaRT 11 : 
Manganese in the Tertiary. 
Excluding the laterite, which probably ranges in age from lower 
tertiary to recent, manganese- ores have been but sparingly found in the 
tertiary formations. In the Subathu division of 
Manganese in the Siwaliko. „. ,., . . <■ i / • , » .1 • t r 
the biwahks m Afghanistan there is a record of 
a black substance that may possibly be manganese-ore, although 
supposed to be graphite An occurrence of manganese-ore. 
Manganese hi the Fossil- possibly in the Fossil-wood group in the 
woud group. Magwe district of Burma, is mentioned on 
page 669 ; whilst a certain occurrence in this formation of masses 
and nodules of ores of this mineral in the Taung-gnu district is noticed 
on page 671. This occurrence is of no economic importance. 
Mans^anese in the Pest-Tertiary. 
An occurrence of manganiferous iron-ore in the post-tertiary rocks 
of the Hanthawadi district in Lower Burma is noticed on page 669- 
Recent Deposits of Manganese. 
General. 
Under the influence of the various meteoric agencies, such as rain, 
frost, and heat, the rocks of the earth's crust are constantly being broken 
up. Some of the constituents of the rocks pass into solution in the 
surface and ground waters and are eventually deposited in ponds and 
lakes, as incrustations on rocks in rivers, possibly as infiUings to 
mineral veins, and also as efflorescences on the surface of the ground. 
Those portions of the materials taken into solution that are not thus 
deposited are eventually carried to the sea in the waters of the rivers 
draining into it. Whilst a certain proportion of the constituents of 
rocks thus passes into solution and thus is disposed of, a considerable, 
and probably by far the larger, proportion is transported mechani- 
cally by water to be deposited in river valleys, lake basins, or the 
sea. The manganese contained in the various geological formations 
may be subjected to any of the influences mentioned above. Conse- 
quently the recent deposits of manganese-ore can be divided into 
four groups, as follows : — 
1. Manganese taken into solution by the meteoric waters and de- 
posited on the land areas, either in lakes, ponds, or rivers. 
2. Manganese that escapes dejiosition on the land areas and is car- 
ried to the sea, where it gets deposited on the ocean bottoms. 
1 \. B. Wynne, Be-. G. S. I., XII, p. Ill, (1879). 
