The Hon. Mr. Strangways on the Geology of Russia. 23 



valley a stream makes its way down to the river, which it enters near the salt 

 magazines*. 



The Volga too, below the town, has no less claim to notice than the Oca. 

 About two versts from the fortress,, on the left side of the road to Cazan, are 

 seen ravines and chasms of the same nature as those so often described. But 

 a little further on, the lofty bank of the Volga becomes wooded and cultivated. 

 On a knoll considerably lower than these banks, but yet raised high above 

 the river, is placed the monastery of Pechersk, and not far from it a large 

 village of the same name. Beyond it is seen, in a situation somewhat similar, 

 the white steeple of the church of Podnolye, another considerable village, 

 which, as well as Pechersk, is built close to the water's edge. The roads 

 down to these villages, winding among the large trees and orchards with which 

 they are surrounded, are no less remarkable for beauty of scenery than for 

 some geological circumstances which may there be examined. We here see 

 for the first time beds of pale red sandstone alternating with the marl. The 

 colour of this sandstone sometimes varies to a dusky green, and is marked by 

 irregular concretions and a sort of globular structure, like those of Borovichy 

 and the Poporca. The red variety sometimes presents a singular appearance, 

 when, with the fracture and aspect of a very ill made brick, it discovers, on 

 breaking, a number of flattened cells or cavities, in which are loose concre- 

 tions of marl, usually of some shade of red, which easily fall out of their 

 receptacles. At the bottom of the cliff along the shore is seen a thick bed of 

 a remarkably hard and compact tuf, the cavities of which are often lined 

 with brown sulphate of lime, deposited stalactitically; it sometimes nearly 

 resembles that found among the solid alabasters, and is capable of taking a 

 fine polish. Fresh- water shells are found in this tuf, though rarely. A si- 

 milar formation exists on the Oca near the salt magazine. 



From the summit of these heights may sometimes be seen a phenomenon si- 

 milar to what has been observed in other places. The blue waters of the Volga, 

 on receiving those of the Oca, which are by no means of an equal degree of pu- 

 rity, are seen to flow uniformly along the left side of the channel; while the 

 other stream on the contrary keeps as regularly along the right. From their 

 point of junction, the difference of colour is too striking to be overlooked by 

 the most casual observer; and it appears but little abated where they pass out 

 of sight. The explanation of the phenomenon is simply this: — The Volga above 



* These magazines are not stored with the salt of the neighbouring districts, but with that of 

 the Steppes of the south-eastern parts of Russia, wliich is supplied at a cheaper rate for the 

 consumption of the interior. 



