THR KAMPA SYSTEM. 
49 
Nechung spur were determinable specimens found. This band is 
overlain by quartzite — a combination suggesting the upper Cretaceous 
series and ferruginous sandstone of Tiina and Kampa dzong. 
Further down the Kyi Chu valley and also up the Trolung Chu, these 
beds are apparently underlain by shale and slate, part of the extensive 
series which has been referred to the Jurassic system. 
The same limestones occur again between Lhasa and the Pempogo 
La and run on through the higher ridges bordering the Lhasa 
plain. Just below the Pempogo La they are underlain by the typical 
Jurassic beds of central Tibet, and in spite of the want of 
palaeontological evidence, it is difficult to resist the conviction that 
this calcareous series, overlain by quartzite, is the equivalent of 
the Cretaceous system of Tiina and Kampa dzong and probably 
connected with beds of similar age known to occur at Nam Tso.^ 
Throughout the rest of the area visited Cretaceous beds are 
apparently absent, though, as already stated, they may occur among 
the metamorphosed rocks between Gyantse and Kampa dzong. 
The extent of the system at Nam Tso is quite unknown. 
CHAPTER VIL 
THE KAMPA SYSTEM— {continued). 
On every section on which it has been found, the uppermost 
Cretaceous (Tiina) limestone is invariably over- 
Ferruginous sandstone. , . , , , , . r , • , r 
lain by a bed — about 200 feet thick — of coarse 
sandstone, gritty and slightly conglomeratic in parts and fre- 
quently highly ferruginous. In the hills around Kampa dzong, 
it contains small segregated masses of iron ore, usually one of the 
hydrated forms, but occasionally pure haematite. The change from 
' Supra p. 40. 
( ) 
