4 
BALL AND SIMPSON: COALFIELDS OF INDIA. 
felspathic and are made up of grains of quartz and decomposed 
or kaolinized felspar, the latter characteristic distinguishing 
them from sandstones of Talchir age. The typical Barakar 
sandstone is white, but other tints occur and in some parts 
predominate. The conglomerates are made up of small, well- 
rounded, quartz pebbles, usually embedded in a white sand- 
stone matrix. The shales are grey, blue, or black, and are 
usually arenaceous and sometimes micaceous. The coals of the 
Barakar stage all agree in having a peculiar laminated 
appearance, due to their being composed of alternating layers of 
bright, and dull, shaly coal. Some of the seams exhibit a 
peculiar spheroidal structure, and round balls, up to more than 
a foot in diameter, break away from the mass when the coal is 
mined. 
Overlying the Barakar stage in the Raniganj, Jharia and a few 
J ^ J other coalfields of the Daniuda valley comes the 
Ironstone Shales stage. It attains a maximum 
thickness of about 1,500 feet, and is composed of black or 
grey shales with lenticular bands and nodules of clay iron- 
stone, some of which is of the carbonaceous variety known as 
blackband. 
In the Damuda valley the highest member of the Damuda series 
is the Raniganj stage, which attains a thickness 
The Ramganj stage. ^^^^^ ^^^^ .^^ Raniganj coalfield. It is 
chiefly composed of sandstones with some shales, and coal- 
seams. The sandstones are usually coarse and massive, white or 
brown in colour, showing decomposed felspar, and obliquely 
laminated. The shales are grey, red, brown, or black in colour 
and are occasionally ferruginous. The coal has the same peculiar, 
laminated appearance as that from the Barakars. 
In the Narbada valley the rocks of the Damuda series overlying 
the Barakars are known as the Motur and 
Bijori stagi" Bijori stages. They are chiefly made up of an 
immense thickness of sandstones, and do not 
contain workable coal-seams. 
In the Godavari valley the equivalent beds have been called the 
Kamthi group. They are not less than 6,000 
The Kamthi beds. , . , . , \ . , , , ' , , 
feet in thickness, and consist of quartz-pebble 
conglomerates, ferruginous grits, sandstones of varying characters. 
