GENERAL DESCRIPTION OP AREA AND ROCKS. 5 



The Himalayan range has been commonly divided into three oro- 

 graphical zones : — the great range of snowy peaks, 



Darjiling hill terri- 

 tory belongs to zone of which, roughly speaking, form the axis of the 



chain ; the Lower or Outer Himalaya, forming a 

 broad belt of mountains of inferior, but still considerable, altitude south 

 of the snows ; and thirdly, the comparatively low hills forming the Sub- 

 Himalayan zone, either as ridges and spurs contiguous with the outer 

 hills or separated from them by c duns ' (flat-bottomed longitudinal 

 valleys), of which latter the Sivalik hills in the North-West Provinces 

 are the type.* These detached ridges are unrepresented along this 

 portion of the Eastern Himalayas, where the Sub- Himalayan zone is 

 locally even wanting altogether. , 



The basin of the Tista within the hills approximates to an oblong in 

 form, with the longer axis north and south. Near the north-western and 

 north-eastern corners tower the giant peaks of Kanchinjinga (28,156 ft.) 

 and Dankia (23,189 ft.) at a distance from each other of rather less 

 than fifty miles, and respectively about sixty and seventy miles from the 

 plains. From Kanchinjinga the Singalela ridge runs southwards, divid- 

 ing Nepal and the valley of the Tambar from Sikkim and that of the 

 Great Rangit. It is the continuation of this ridge in a south and then 

 south-easterly direction, by Tanglu, Senchal, and Sitang, with its various 

 lateral spurs, which constitutes the Darjiling hill territory west of the 

 Tista. From Dankia a lofty ridge runs southward by the Gnaream 

 and Chola peaks, separating the basins of the Tista and the Tursa from 

 each other. At Gipmochi (11,518 ft.) this ridge divides into two great 

 spurs ; one running to the south-east and the other to the south-west, 

 including between them the valley of the Jaldoka. It is the lower half 

 of the south-western spur, with its ramifications, that constitutes the hills 

 of the Daling Sub-division. The hills between the Jaldoka and the 



* Vol. Ill, pt. 2, p. 5. 



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