AREA SOUTH OF THE SAFfiD KOH. 97 



ing north and south. Between the Samana range on the south and 

 the Safed Koh on the north there are three main ridges and four 

 troughs, the order being from south to north :— 

 Samcina Range- 

 Valley of the Khanki river. 

 Tsappar Range- 

 Valley ot the Mastura river. 

 Western portion of the Targhar Range 1 — 



Maidin and Wara*n valleys. 

 Eastern portion of the Torghar range 1 — 



B5ra valley. 

 Safed Koh and Surghar ranges. 

 The above ranges all present steep scarps to the south, but slope 

 away more or less gently to the north. 



As already noticed by Mr. Griesbach, 2 the rocks of this area 

 appear at first sight to dip steadily at low angles 



Structural Geology. , . . . . , 



to the north, but on closer inspection are round 



Beds everywhere much to be thrown into a series of folds, frequently 

 reversed. Not only is this true of the area 

 immediately to the north of the Samcina range, but from that range 

 up to AH IVrasjid in the Khaibar, this feature is constant. The rocks 

 have undergone much folding, and, if examined in detail, their struc- 

 tural geology is highly complicated (see PI. VI). The key to 

 the structure of the whole area is, however, the inverted fold, and 



when examined in this light, the whole section 

 Inverted folds. 



from the Khaibar to the Samana resolves itself 

 broadly into a series of reversed flexures, often much complicated 

 by crumpling and faulting, the faults frequently taking the form 

 of overthrusts. 



The recognition of the various beds, being dependent either on 



Lithological characters fossils or on the Hthological character of the 

 of the rocks not distinctive, rocks, is, therefore, a matter of no small diffi- 



1 As shown on map of " Tirah and surrounding country." (i "s=2 miles. Jan. 1893.) 



2 Op. cit.y p. 80. 



H ( 97 ) 



