100 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



to deterimine the true dip which is of the usual high amounts, 

 much obscured in places by surface deflection, but giving in general 

 a dip of 40 — 6o° S.E. or S.S.E. This is especially marked in the 

 vicinity of Koti-ki-khubbur, where the road from Berwal joins the 

 Hureepoor-Abbottabad road, five miles from Abbottabad. 



Here the basal conglomerate of the Infra-Trias is best seen in 

 its unconformable position above the slates. This unconformity is 

 one of the most important geological features of Hazara. It admits 

 of no doubt, and we are thus early introduced to that sharp line of 

 division separating everything that is above it from the great Slate 

 series beneath. 



The Infra-Trias is ushered in by this conglomerate, and it needs 

 but a glance at the great crags which form the ridge north of 

 Tanakki to see that they — composed of an ascending series of sand- 

 stones, quartzites, and limestones, coming above the conglomerate — 

 are dipping en masse in an exactly contrary direction to the slates. 

 Besides this, very many of the exposures on the hill slope individually 

 shew the over-stepping of the conglomerate across the truncated 

 edges of the Slate series. 



The nature of this conglomerate has already been described. 

 It is sufficient here to remark that its character and obviously derived 

 origin from the rocks immediately beneath tend to strengthen the 

 conclusion as regards the profound stratigraphical break indicated by 

 it. It is not difficult to follow this conglomerate round in a north- 

 easterly direction for some way up the Tanakki glen ; but due north of 

 Tanakki it is generally hidden locally by debris from the crags above, 

 or by slip faults in part connected with the great north Sirban 

 fault. The purple shales follow in normal sequence above, and these 

 in turn give way to the deep purple sandstone. They in turn pass by 

 a lithological transition into similarly coloured limestones which 

 higher up become flesh-pink and then white. All these belong to 

 the Infra-Trias group, a very fine section of which is to be found 

 above Tanakki by ascending a cleft or gully in the precipitous crags 

 north of that place. The ascent is easy. 

 ( 100 ) 



