62 BOKARO COAL-l'IELD. 



Economic. — The economic value of the Ironstones is well known. 

 In the Bokaro Field the stones are rather siliceous; and the Native 

 workmen seem to prefer the iron from, the middle Barakars for smelting. 



In the Kaininpoora Fields the ore worked is almost exclusively 

 that of the lower group. 



Section 3. — The Raniganj group. — This group occupies the area 

 between the Bokaro and the Dhungadugwa rivers. The beds dip on the 

 whole to the westj towards the basin in which the Panchet series rests. 

 There is no difference in lithological character between the rocks of this 

 group as developed in the present area and those of the Jherria and 

 Raneegunj districts^ to the descriptions of which reference need be made. 

 The only facts of any interest to record in connection with the group here 

 are, the unconformity which it exhibits to the lower groups of this series, 

 and the general absence of any serviceable beds of coal. The uncon- 

 formity is best seen in the neighbourhood of Hosir and Sarum^ where the 

 Ironstone shales are so completely overlapped that the Raniganjs rest 

 directly upon the Barakars. 



In the Jherria Field, no unconformity was made out between any of 

 the sub-divisions of the Damuda series^ but Mr. W. T. Blanford, in bis 

 report on the Raneegunj area, speaks of a break between the lower and 

 middle groups. 



The observations in this district tend, on the contrary, to show that 

 there is here a more intimate relation between the Barakars and the 

 Ironstones, than between the latter and the Raniganjs ; and that in fact 

 unconformity exists only between the middle and upper groups. 



The Ironstone shales in the Karunpoora Field, thin out completely ; 

 and it is questionable whether they ever set in again further to the west i 

 the mode of occurrence of the group suggesting that, although spread 

 over a considerable area, it is comparatively local, and confined to the 

 coal fields of the Damoodah valley, 



( 100 ) 



