PHYSICAL FEATURES. 5 
and granuHtes, which are probably in part the equivalents of the 
similar Archaean rocks of the Peninsula and Burma, The com- 
plete absence amongst these of fossiliferous sediments leads us to 
the conclusion that this part of the Himalaya belongs stratigraphi- 
cally to the Peninsula, and has from earliest Palaeozoic times been a 
land surface, in fact the northern coast of Gondwanaland. 
This zone comprises all the highest peaks of the Himalaya, the 
relics of the snow-clad mountain range which was originally the line 
of water-parting between the S.-N. and N.-S. drainage systems. 
Now, however, it has been cut through by the more active rivers of 
the southern watershed, which have captured much of the watershed 
of the northward-flowing tributaries of the Tsangpo, and the once 
continuous range is now merely a series of isolated peaks or groups 
of peaks, which can, however, be followed from end to end of the 
Himalaya. 
Here and there branches of granite diverge from the main mass 
of the crystalline zone, and force their way through the sedimentary 
beds to the north. Throughout the greater part of the Himalaya, 
such off-shoots are not apparently of great extent : but in the area 
with which we are at present chiefly concerned, they are both 
numerous and extensive. The most important of these subordinate 
intrusions diverges from the central core on the western boundary of 
Bhutan and Chomolhari and runs towards the north-east, forming the 
range of snowy peaks which constitutes the water-parting between the 
drainage flowing northwards to the Tsangpo and lake Yamdrok and 
the southward-flowing rivers of the highlands of Bhutan.^ 
Further off-shoots run from the Lingslii range northwards to 
Nojinkangsang and the Karo La, the only group of snowy peaks 
between Northern Bhutan and the Tsangpo, and a mass of intrusive 
granite, genetically related to that of the crystalline zone, is found 
' This range is a perfectly definite orographic unit, but has no name since 
the Tibetans name only peaks and passes; it might be conveniently called the 
Lingshi range, from the pass of that name, leading through it from the Tuna 
plain to Bhutan, 
( 126 ) 
