HAYDEN : GEOLOGY OF NORTHERN AFGHANISTAN. 



Siwalik age. These beds form an anticline, of which the northern 

 limb has a comparatively steep dip, sometimes as much as 30°, whilst 

 the southern is flatter. 



5, Siwalik sandstones and conglomerates. 4, 3, Metamorphic limestone and slate. 

 1, Alluvium of the Surkh-ab. 2, Granite. 

 Fig. 4. 



Diagrammatic section across the valley of the Surkh-ab between the Siah Koh 

 and the Safed Koh. 



The road enters the Siwalik beds just below Fort Battye, and 

 continues among them for a short distance beyond 

 urkhpul. Gandamak. At the low pass between Gandamak 



and Surkhpul they are reduced to a narrow strip of sandstone and shale 

 lying unconformably on limestone and granite belonging to the crystal- 

 line series of the Siah Koh. To the west of the pass they expand again 

 and cover all the older rocks, which, except in some small hills to the 

 south of Surkhpul, appear only in the valleys. The Siwaliks also run 

 high up the southern slopes of the Siah Koh between Surkhpul and 

 Jagdallak, and are found on the Jagdallak pass (6,200 feet) between 

 these two places. At about two miles below the pass and at a short 

 distance from Jagdallak, the beds are very highly inclined, being some- 

 times even vertical. This high inclination has been observed at several 

 localities in the neighbourhood of Jagdallak and the Siah Koh. The 

 disturbance is always most marked where the beds abut against the 

 hill'-masses, and this points to comparatively recent movement in the 

 direction of elevation of the hills. 



To the east of Jagdallak the Siwaliks run up to the steep hills of the 

 crystalline belt of the Ruby Mines. The lime* 

 stone is here about £ mile wide, and is broken Up 



