^".^■^f^- GEOLOGY OF THE CENTRAL HIMALAYA. 443 



The Central Himalaya is divided into two portions: — (1) the 

 Southern Range, which, including many of the higher mountains, 

 may be said to begin with the mass of the Nampa Peaks on the 

 north-west frontier of Nepal, and to end near the Spiti valley ; and 

 (2) the Northern Range, which stretches parallel to the other range, 

 In some places separated by broad valleys 15,000 feet or more above 

 sea level, and in others connected by ridges. 



The Southern Range of the Himalaya averages 20,000 feet in 

 elevation, and from 16,000 feet upwards there is perpetual snow. It 

 is a true range though not a continuous ridge, being deeply furrowed 

 by rivers that rise to the north. The rocks are mainly crystalline, 

 being gneiss and schists with great granite intrusions. 



The Northern Range is more continuous, but of lesser elevation, 

 and comparatively free from snow. It consists of a system of great 

 flexures of sedimentary rocks, ranging from Pala30zoic to Tertiary, 

 and their description forms the chief subject of the present memoir. 



Some notion of the physical features of the area may be gathered 

 from the foregoing statement ; but it may be interesting to quote the 

 following passage : — 



"When travelling northwards from India to Tibet, through the 

 deep valleys and over the great passes of the Himalayas, the eye 

 becomes so accustomed to stupendous mountain masses, and a 

 seemingly interminable succession of ranges and steep cliffs, that 

 when finally reaching the last crest of the watershed, the view over 

 the Hundes Basin which meets the eye, fairly takes one by surprise. 

 At one's feet stretches, as far as the eye can see, an apparently level 

 expanse of country, a level in which, at that distance, all lower ridges 

 and inequalities seem to disappear. All of it is more or less of a 

 brownish-green colour — bare patches of gravelly soil with streaks of 

 bright green pasturage. Not a soul, nor living creature apparently, 

 inhabits this immense waste, only rarely and at great intervals one 

 may detect a solitary black tent belonging to a party of nomadic 

 shepherds, whose flocks may be grazing in the sheltered depressions 

 of this great expanse, where better pasturage is possibly found." 



Beyond this great expanse of flat country may be seen the 

 serrated elevations of the Kailas range, sparingly covered with snow, 

 although the heights average about 18,000 feet. 



The structure of the Himalaya is broadly that of a succession of 

 inverted flexures, leaning over towards the south-west. Two great 

 anticlinals, formed of immense flexures of older crystalline formations, 

 can be distinguished. Fossiliferous stratified rocks are preserved in 

 the synclinals, but faulting and the intrusion of igneous rocks have 

 modified the normal order in places ; for the inverted flexures are 

 often pushed one over the other along planes of dislocation, that form 

 oblique faults of great magnitude, and produce the " scale-structure" 

 so common in most areas of folding. The Southern Range is formed 

 perhaps of the larger of these main anticlinals, and there is only left 

 what might be taken to be a conformable series of metamorphic 

 strata. North of this great inverted flexure there follows a huge 



