METAMORPHIC CREST OF THE ARCTIC URAL. 
407 
troops of rein-deer, and by whose aid we ascended the mountain. Fiom the 
summit of Petchora-ill-is (about 3600 feet above the sea), the spectator casts his 
view eastwards into the wide and deep valley of the Sosva (see p. 405), occupied by 
dense dark forests, beyond which are ranges of heights 1 , called Telbunniar by the 
natives. Still further to the east are green dark-wooded plains, in which a lew lakes 
appear, and in the distance are the boundless, yellowish steppes of Siberia. To 
the west, on the contrary, the view is soon arrested by numerous rocky elevations, 
which surround the upper woodland depression in which the rivers Yegra-laga 
and Petchora have their origin. The crest itself is seen to range very distinctly 
from south to north, along a series of broken, rocky summits, whose sides are, for 
the most part, covered with debris or grassy slopes. 
The mountain of Petchora-ill-is consists of chloritic and micaceous schists, often 
highly quartzose, in beds obscurely stratified, and approaching to veiticality. 
These rocks occupy a broad zone, including another mountain, called by the Zyrians 
Balvano-is, or the Mount of Idols, which owes its name to a peculiar phamome- 
non. On its rounded verdant summit are seen certain grotesque and rude columnar 
masses of chloritic quartz rock, mostly attenuated towards their base, and occasion- 
ally attaining the height of 100 feet. These natural monolithes are eight in number, 
and as five of them lie in the same alinement, or from north-east to south-w'est, 
we might at first suppose that they were indications of a great vein. Their 
schistose and depositary character, however, and the irregular distribution of the 
other three pillars, render it more probable that they are simply the hardest por- 
tions of the rock, which have most effectively resisted destruction. 
To the west, the geologist descends through similar quartzose, chloritic and mi- 
caceous rocks and marshy forests, into the vast alluvial plain of the ^egra-laga. 
This plain is much occupied by gravel and rounded blocks of medium size, all de- 
rived from the adjacerd chain. A few deserted huts are to be found which formerly 
served as places of barter between the Zyrians and the Ostiaks. 
Looking eastwards from this tract, we were struck with the conical form of a 
mountain named Cosis, which we supposed might be trappsean, but, judging from 
specimens brought to us by the natives, we found it to be composed of the same 
rocks as the Petchora-ill-is. 
Lower and Upper Silurian Rocks .— In descending the Yegra-laga we observed 
on both its banks alternations of argillaceous slaty schist, with bands of black 
1 According to Strajefski these hills are trappsean. 
3 G 2 
