86 W. BLANFORD;, WESTERN INDIA. [PaRT II. 



stood up above the general level of country. Where denudation has so far 

 removed the traps that the old surface is once more visible, the hard ridges 

 again protrude, while some trap yet remains in the hollows between them. 

 Trap dykes occasionally occur in the metamorphics. They were 

 especially observed in the jungles north-east of 

 Poonghat. They appeared at that place to have two 

 principal directions, south-east and east-20°-north, the latter coinciding 

 with the lamination of the metamorphics. 



A very interesting section occurs in the Tawa (a) river near its junc- 

 tion with the Nerbudda. At the mouth of the Tawa, 

 Tawa section. . . 



the Bijawur limestone is seen presenting a peculiar 



concentric structure; the alternating bands of siliceous and calcareous 

 minerals, instead of being plane, are concentric around nuclei of quartz. 

 Many of these concentric masses are of great size. 



A little further south, there is an immense mass of hard quartzose 

 breccia similar to that seen north of the river, north-west of Chandgurh, 

 composed of purplish jasper-like rock with enclosed angular fragments of 

 quartzite. Upon this rest Vindhyan shales, sandy as usual, and passing 

 upwards into the typical quartzite-sandstone, which forms hills west 

 of the stream. 



It is difficult to say what is the position of the breccia. It was at 

 first supposed to be Bijawur, but the occurrence of similar breccia ap- 

 parently interstratified in the Vindhyans on the Nerbudda close by, 

 renders it possible that it may belong to that series.(5) The shaley beds 

 appear to be unconformable upon the breccia, and the breccia upon the 

 Bijawur limestone, but neither unconformity is very clearly made out, 

 and apparent unconformities of breccia or quartzite beds resting upon 

 Bijawurs must be regarded with suspicion on account of the pre- 

 dominance of cleavage foliation in some of the beds of that series and its 

 absence in the hornstones and quartzites. 



(«)- This is the smaller Tawa called the Chota Tawa or Sooktawa rivers. 

 (&). This was pointed out by Mr. Mallet. 



< 348 ) 



