THE DAMTJDA SERIES. 3l 



somewhat like those of the genus sigillaria. Imperfectly preserved 

 leaves of ferns are numerous. 



The greatest thickness of the ironstones is about 600 feet, between 

 Nappo and Usko^ and then there is a gradual thinning out to the west. 



In the CJiano basin^ there is a very good development of the group 

 north of Rikba. The drawbacks to the utilisation of the coal of this 

 area which were enumerated before, apply equally to these ironstones. 



As a source of supply we must look to the band which occurs in the 

 main body of the field. 



Rdmganj group. 



The lower boundary of this group in the northern portion of the 

 field partakes of the same uncertain character as the upper boundary of 

 the ironstone shales. Very few contacts of the two groups are to be 

 met with ; as most of the rivers are shallow and sandy, and expose 

 extremely imperfect sections. A very large area of the Haniganj beds 

 is obscured by alluvium, and thus the relations of the beds are often con- 

 cealed in the most critical spots. 



In the southern half of the field more rock is exposed, but the beds 

 are not so distinctive of the group, as they are in other localities ; and 

 the complete absence of ironstones renders the fixing of the boundaries 

 in many places a very arbitrary matter. 



The texture of the Raniganj sandstones is, generally speaking, fine ; 

 and like the normal upper Barakars, they contain none of those coarse 

 sandstones and grits so distinctive of the lower Barakars ; and as coal 

 occurs in either group, there is no sharply marked character by which 

 to be guided. 



The distribution of the Raniganj group is very simple : one small 

 area in the Chano basin, and a larger, fringing the Panchet hills. 



In the southern and western portion of the field the ironstones 

 are entirely overlapped. 



( 315 ) 



