382 
DESCENT OF THE SEREBRIANKA. 
traversed. Poor gold washings, now abandoned, were formerly worked at Kedrofka 
in a depression near the axis, and deposits of brown iron ore between that and 
Rabina Gora, slightly diversify the features of the subsoil, which invariably present 
the facies of metamorphic rocks, amid which one band of white crystalline lime- 
stone is apparent, and has, like all the other strata, a persistent strike from south 
to north. At the village of Lukovka, thirteen versts from Serebriansk and on the 
western slope of the chain, small greenstone protrusions were first observed by 
Colonel Helmersen, the position of which is highly interesting in exhibiting a 
central axis of metamorphic rocks enclosed between eruptions of igneous matter 1 . 
It was, indeed, very gratifying to see, that in proportion as we receded from the 
igneous zone upon the east, the sedimentary strata gradually parted with their tal- 
cose, quartzose and chloritic character, and assumed the appearance of ordinary 
argillaceous schist, with bands of grauwacke, grit and psammite, all parallel to the 
crystalline axis of the chain. Arrived at Serebriansk, the appearance of the strata 
at the edges of the excavations around the Zavod and along the banks of the ar- 
tificial lake and of the river Serebrianka, led us to suppose, that the strata were 
not of higher antiquity than the Uppermost Silurian, particularly as we found the 
Leptama Uralensis and Terehratula aspera in a band of impure limestone. 
Descent of the Serebrianka River to its Mouth . — The Zavod of Serebriansk is 
established for the purpose of catching the waters of the Serebrianka river before 
they enter into a narrow and tortuous defile of some length, by which they escape 
to the Tchussovaya. A large lake is thus established above the works, by the 
water of which the ores of Blagodat are to a great extent worked. Having 
expressed our desire to descend the Serebrianka to its junction with the Tchus- 
sovaya (for we saw by the Map that its banks must expose good sections of the 
strata), it was most mortifying to perceive, that the river beneath the water-works 
was nearly dry. The Imperial instructions, however, for the fulfilment of our 
wishes were not to be slighted, and by daybreak after the evening of our arrival 
at Serebriansk the worthy Director of the establishment, M. Moskvin, having let off 
a large body of water from the upper reservoirs or lakes, had in one night created 
a river for our use, on which by daybreak a few canoes and a larger boat were 
already afloat and manned ! 
In this little flotilla we descended the wild and uninhabited gorge, though not with 
1 M. Le Play also speaks of hornblendic rocks on the western slope of the axis, but to the south of 
this section. (Comptes Rendus, October 21, 1844, t. xix. p. 853.) 
