DESCRIPTIVE GEOLOGY: NUMMULITIC ZONE. 1 77 



(e) That the faults, as would be expected in such an area of 

 great disturbance and flexuring, are generally of the 

 nature of reversed strike, or fold-faults, whereby the 

 outliers of the younger rocks are made to plunge or 

 dip down on one side (generally the north-west) 

 against the older series. 

 5. One of the most patent facts about this zone is that the 

 sculpturing of the area by denudation has been very intense and long 

 continued, as is testified by the great size of the valleys and plains 

 excavated in this zone, by their irregular course, either with or across 

 the strike or at any other angle to it, by their great depth, and by 

 the fact that no single instance is to be found throughout the zone of 

 uplift areas of what is known as the Uinta type, that is to say flexures 

 that by their original form have given immediate shape and character 

 to the resulting mountains and glens ; in other words, no valley is ever 

 a pure and simple synclinal, and no hill is a pure and simple anticlinal. 

 We may also note, as further exemplifying the great activity dis- 

 played by denudation, that most of the ridges steepen towards their 

 crests and are very deeply scored by side ravines. 



6. That the topography, resulting from (5), presents the high 

 contrasts of towering crags and culminating peaks overlooking the 

 deep river and stream- beds, and shews a marked tendency to a 

 natural division of its surface into isolated ranges and culminating 

 points with radiating spurs, e.g., Gifndgurh range, and the Sirban, 

 Tope, Tandidni, Taumi, and Mian-jani centres ; from each of which 

 its own hill-sides descend in spurs and buttresses and give to it a 

 distinct individuality of its own. 



Chapter IV.— Descriptive Geology— contd. 



C — The Nummulitic zone. 

 Orography, 

 The boundaries of this zone have been given, page 8j. The 

 zone is an exceedingly characteristic one. Throughout its whole extent 

 N ( 177 ) 



