i;S MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



on the map it may be seen to be very sharply defined by bounding 

 faults or overthrusts from its two neighbouring zones. Like the Slate 

 zone it takes its name from the rock most prominently displayed at the 

 surface, viz., the Nummulitic limestone, although unlike the Slate zone 

 this is not the lowest formation visible but very nearly the highest. 

 Wherever through erosion, or by reason of the crumpling and faulting 

 of the rocks, the lowermost strata of the zone are exposed, they 

 belong uniformly to the Trias. We have already seen that the Infra- 

 Trias series was unrepresented along the southern sub-zone of the 

 great Slate zone, and therefore we should not expect to find it 

 anywhere visible in this still more southern zone of rocks ; and this 

 is found to be the case. But besides this, there is also no visible 

 occurrence of the Slate series beneath the Trias. If we follow up any 

 of the long straight longitudinal valleys, or traverse down any of the 

 deep-cut transverse gorges belonging to this area we shall alike 

 find the Trias limestone to be the apparent base of everything — the 

 geological foundation of this zone ; just as the slates, and nothing 

 below them, were found to be the lowest exposed strata in the Slate 

 zone. 



One of the most striking orographical features of this zone is 

 the absence of wide alluvial valleys such as the Dore, and also the 

 absence of plains such as the Abbottabad, Hureepoor, and Man- 

 sehruh plains. Another very noteworthy feature of this zone is 

 that the main rivers, streams, and valleys are parallel to the 

 general strike of the country (E.N.E. — W.S.W.) ; and between 

 them run parallel hill-ranges. The valleys are narrow and winding, 

 and sometimes of considerable steepness, whilst the intervening 

 ranges form either continuous masses of the nature of scarped, craggy, 

 narrow but broad-topped table-lands, or, if they are cut through by 

 transverse streams, the latter are of the nature of deeply-cleft gorges, 

 so sharp and precipitous that they are hardly visible until one is 

 directly over them. There are also no isolated hill-masses like those 

 of Sirban, Gundgurh, Tandidni, etc., in this zone, nor are there 

 disjointed outliers of younger rocks above older with circular cr 



( 178 ) 



