Chap. IV. § I.] the damuda series. 43 



conformity in dip. The run of congloineritic sandstone extending into 



the ironstone shales is most anomalous and difficult to account for, the 



only explanation which appears probable is, that 

 Old shores of basin. 



it may have been a beach deposit, formed from 



the Lower Damudas, and thus resembling them so closely as to be 



undistinguishable when consolidated. A sharp change in the direction 



of the strike, which occurs just where ironstone shales come in beneath 



the conglomerate bed, supports this probability. 



It is also possible, as the ironstone shales are evidently much thinner 

 South of the Chanch fault than they are to the North, that that 

 fault was partly formed at a period subsequent to the age of the 

 Lower Damuda group and antecedent to that of the ironstone shales, 

 and that disturbance and denudation of the former took place prior to 

 the formation of the latter. 



Altogether there seems to be little reason to doubt that a slight break 

 of continuity exists between the Lower Damudas and the ironstone 

 shales. But no evidence of a similar break has been observed on the top 

 of the ironstones. It may exist : careful search, however, has failed to 

 prove its presence, and the tendency of the evidence at present is to 

 show that the ironstone shales are the lowest portion of the upper series. 



So few good fossils have been obtained from the Lower Damuda 



group, in comparison with the large collections 

 Comparison of fossils. . 



obtained irom the upper series, that the merely 



negative characters exhibited cannot be considered to have any great 

 weight in confirming the value of the two divisions. Fossils are 

 not rare in the ironstone shales, though badly preserved. But, 

 although good specimens of fossil plants are, in consequence of 

 the sandy nature of the beds, less frequently obtained from the Lower 

 Damuda, the impressions themselves are quite as abundant, and as 

 generally scattered as in the Upper series. The latter alone have fur- 

 nished in the Damuda field forms of Pecopteris, Trizygia, and a plant 



