24 



SUB-HIMALAYAN ROCKS OF N. W. INDIA. 



[Chap. II. 



o x; 



is* 



A 



£ 1 



60 3 



5 W 



M H 



into a sharp, coarse, dusty sand, which is carried 

 in quantities to the neighbouring stations as an 

 ingredient for mortar. Although very regular in 

 its position, this sandstone varies considerably in 

 thickness within short distances. It is important 

 to have unmistakeable evidence of this fact, such 

 as we find in the continuous sections round the 

 bases of these hills, because we shall have to ap- 

 ply it freely in attempting to connect these beds 

 with others at a distance. Along the south-east 

 side of the Boj there are not more than fifteen or 

 twenty feet in thickness of this sandstone ; more- 

 over it is here thin bedded, like the gritty slates be- 

 low it, and like the limestone over it ; its charac- 

 ters are, however, well preserved. Round the south 

 and south-east of the Krol there does not seem to 

 be much more of it than just noticed on the Boj, 

 but on the west and north of the Krol it must be at 

 least one hundred feet thick, and is in massive beds. 

 Everywhere on these hills the coarse sandstone 

 The lower limestone is overlaid by limestone. 

 and shales. This too is subject to very 



decided changes in thickness and in character. 

 The most conspicuous section of it is at the south- 

 east angle of the Boj. There we have at least 

 three or four hundred feet of clear, blue, compact 

 limestone, in very regular, thin, three to six inch, 

 beds ; it here and there contains some well-formed 

 nodules, and regular strings of chert ; while else- 

 where, as prominently along the eastern side of 

 the Krol, there seems to be no more than a very 

 few feet of the pure hard limestone, it being to 

 a great extent replaced by thick and thin beds of 

 a very fine semi-indurated marl, or calcareous silt, 

 that breaks up into acicular splinters. In some of 

 the beds of the Boj section an approach to this 

 variety is easily detected. Among all these beds, 

 as we ascend, shaly clays are introduced, often 

 having a light, but bright, pink, and sometimes 

 a mottled gi-een colour. These clay rocks oc- 

 casionally give rise to a little confusion when 

 they occur at the contact with the Sabaihu 

 group. The average thickness of all these argillo- 

 calcareous beds must be from five to eight hundred 

 feet. 



