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



St. Andrus. Its most southern known point is near Suvenoya^ twenty versts 

 from Wyborg. 



The northern shore of the Ladoga is much broken and indented ; its rocks 

 present several varieties of red and grey veined marble, formerly much used 

 at Petersburg : that of Reuscola was the most celebrated. Further eastward, 

 near Cerdopol*, were formerly worked veins of sulphuret of copper, but I 

 know not in what rock ; of late some attempts have been made at working both 

 copper and iron ores, higher up the country near Eno, but with indifferent 

 success. 



Nearly opposite Cerdopol, and at a considerable distance in the lake, is 

 the Island of Valaam, famous for its monastery, and for a magnetic sand 

 used in Petersburg for writing-sand ; it is the largest island in the lake. 

 North-east of Cerdopol is the Lake Shuya, near which was formerly worked 

 a rich iron ore in veins, which has since been abandoned on account of the 

 superior cheapness of the iron worked at Petrozavodsk, or procured in the 

 same manner as at that place f. 



The Lake Onega is bounded on its north-western shore by rocks of dark 

 green jasper-breccia, on the north by a veined marble sometimes resembling 

 that of Reuscola, sometimes greenish and full of tremolite, much like the mar- 

 ble of Glen Tilt. It is crystalline in its texture, and seems undoubtedly a pri- 

 mitive limestone. The western coast consists of a red sandstone of great hard- 

 ness and solidity: this, as well as the breccia and marble above mentioned, is 

 used in Petersburg as an ornamental stone. Blocks of the red sandstone are 

 found over a large tract of country to the southward, comprehended between 

 the Lake Onega, Petersburg, Moscow, and Kostroma ;{:. 



A striking resemblance may be traced in the features of the two lakes and 

 ot the Gulf of Finland. In each case, the northern shore is formed of the older 

 rocks, is much broken and indented, and skirted with islands ; and in each case 

 the deep waters are found alon^ those coasts. Sand or sandstone forms the 

 east and west sides, and the necks of land which divide the respective basins. 

 The southern boundary of each is a marsh, behind which, at a small distance, 

 is a chain of hills of secondary limestone, of one and the same formation. The 

 outlet of each is similarly situated ; the Svir connecting the Lakes Onega and 



* In the Swedish maps Sordivala. 



f See hereafter, p. 10, 



J I give these as the extreme known localities : of course there is no prescribing absolute limits 

 to the rolling of a boulder. The red sandstone boidders of Uryavetz are studded with pebbles of 

 white quartz, and are used as paving.stone at Nishne Novgorod. They are also found on the Oca. 



