38 MALLET^ VINDHYAN SERIES. 



little distance up stream from the Koteesar limestone, several thin bands 



of it are interstratified with porceUanic shales. The fact of these bands 



being only a few feet thick is very strongly against the supposition of the 



rock being contemporaneous trap. 



Between the Rehund and Koel the porcellanic beds gradually pass 



above into those of ordinary shale and sandstone. 

 6. Shale and sandstone. « -n- • p i . • i . ^^ i i 



East 01 ripia tor about eight miles a sandstone is 



found in a low range of hills dipping north-20"-east at 30°, which constitutes 



the highest beds of the series occurring south of the Sone in this region. 



At the mouth of the Ghagur Nuddee is some massive whitish sandstone, 



to which it seems a similar position in the section should be assigned, as it 



appears to underhe the shales which stretch along the north bank of the 



Sone at intervals from this to Jadoonathpoor, where they are lost under 



the alluvium. At Jaradag they are black and brittle with interstratified 



layers of sandstone. Immediately below the limestone (7), the beds are 



green and fawn-colored aluminous clunchy shale. . . 



It appears that at Burdhee, concretionary black shales belonging to 

 No. 8 rest directly on the porcellanic beds, and that Nos. 6 and 7, as well 

 as the sandstone of 8, are therefore entirely absent ; a fact evidently con- 

 nected with the constricted nature of the lower Vindhyan area along 

 here, in which the whole series is undoubtedly thinner than elsewhere. 

 To the west the beds of 6 reappear, and are largely developed along the 

 Mahanuddy. Their general character is that of a black, or greenish- 

 black brittle rock, in beds mostly ^ to | an inch thick, but often 6 inches or 

 more. Sometimes they are more indvu-ated and of a yellow color. They 

 are intersected by several lines of jointing, the three most prominent 

 of which divide the strata into regular triangles with angles of 

 30° 45° and 105°. Ripple marking is almost universal. Often, as 

 in the Japamn Nuddee from Bijragoogurh downwards, the entire surface 

 of every layer is covered by rippling, besides which sun-cracks and the 

 marks of rain-di'ops are very common. All three may frequently be 



( 38 ) 



