The Hon. Mr. Strang ways on the Geologi/ of Russia. 37 



which forms the bulk of the country of Shirvan. The hills of Dagestan and 

 Shirvan nearest the sea on the north of Bacou^ are composed of a shelly 

 limestone. The bituminous formation re-appears in the Isles of Naphtha^ on 

 the eastern shore of the Caspian, and, it is said, also in Georgia. 



Salt Steppe. — The most remarkable of all the steppes is that which, lying 

 at an extremely low and generally uniform level, extends between the Black 

 Sea and the Caspian, and of which Pallas has partly traced the ancient boun- 

 daries. It is marked by an extreme want of fresh water, and is covered with 

 sand and recent shells, such as are now found in the neighbouring seas. 

 The lakes and pools which it contains are mostly salt*, and the scanty vegeta- 

 tion of the steppe consists of such plants only as are found with us on the sea- 

 coast, or which are of a like nature. The rock under the superficial sand is a 

 hard clay, sometimes left bare. It may easily be imagined that this district is of 

 an extreme sterility, and is consequently scarcely inhabited. 



The origin of this steppe is usually attributed to a change of level in the 

 waters of the Black Sea, which, having burst a passage through the straits of 

 Constantinople, left dry the shallow tract between it and the Caspian. The 

 extent which this sea is supposed to have occupied formerly is loosely traced 

 upon the map ; according to which there must formerly have been either two 

 inland seas, separated by land in the neighbourhood of the Bosphorus, or the 

 Mediterranean must have extended to the interior of Asia, as far as the low 

 steppe continues ; and in that case its eastern shore would have been the 

 high land which, in the steppe of the Kirghis, connects the Altay with the 

 Himalaya mountains. Many considerable islands and peninsulas would have 

 thus been formed, such as the Crimea f , Kharizm, the Beshtan, &c. : for the 

 bed of a strait is said to be traced across the isthmus of Perecop, including the 

 steppe of the Dniepr on the north, and a part of that of the Crimea on the 

 south ; the Lake Aral would have been joined by narrow seas with the Cas- 

 pian on the north-west, and perhaps also on the south-west. And among the 

 smaller islands would have been those insulated hills, which now rise in the 

 steppe between the Volga and Oural rivers, and which consist of alternating 

 strata of limestone, and red and yellow sand, and clay, with salt, gyps, and ala- 

 baster, Uke those which accompany the salt formation in the south of Russia. 



* The salt contained in the ground is frequently said to form an efflorescence on the surface 

 resembliug hoar-frost. Salt rain also is said to fall in the neighbourhood of the Caspian Sea, al- 

 though its waters are much less salt than those of the British Channel, Mherc that sort of rain is 

 not known. 



t See Pliny, Hist. Nat. lib. 4. 



