T. BELT ON THE STEPPES OF SOUTHERN RUSSIA. 843 



45. The Steppes of Southern Bussia. By Thomas Belt, Esq., 

 F.G.S. (Bead June 20, 1877.) 



I first saw the steppes of Southern Russia in the spring of 1873, 

 and under circumstances calculated to impress some of their peculiar 

 features on my mind. I had, in company with a friend, crossed the 

 Caucasus from Tiflis to Vladikafkas. We had travelled by the great 

 military road through the pass of Dariel, and down the stupendously 

 precipitous valley of the Terek. At Vladikafkas we came out on 

 a vast plain, sensibly level as far as the horizon, and running in 

 between and around the spurs of the mountains, like the sea around 

 the headlands of a precipitous coast. I have since then travelled for 

 thousands of miles over similar plains in Asiatic and European 

 Bussia ; but the vividness of my first impressions of the steppe of 

 Vladikafkas has not been dimmed, although my interest in the 

 great plains has been increased by the personal experience I have 

 since gained of their almost continental extent. 



At Vladikafkas I saw no sections to a greater depth than 15 feet. 

 These showed the upper surface of the plain to be composed of 

 about 4 feet of black soil, resting on a fine grey loess-like clay, the 

 base of which was not seen. I was only able to make a short search, 

 and found no organic remains. 



In 1875, and again in 1876, 1 travelled much in Southern Bussia ; 

 and I propose to lay before the Society the information I have 

 obtained respecting the extent, the constitution, the geological age, 

 and the probable origin of the steppe-formations. 



Very fine sections are to be seen around the shores of the Sea of 

 Azof, where for many miles there are continuous cliffs, often more 

 than 100 feet in height, composed almost entirely of the sands and 

 clays to which the Bussian geologists have given the name of 

 " diluvium." The strata near Taganrog have been noticed by Sir 

 Boderick Murchison in his ' Geology of Bussia in Europe ;' but the 

 diluvial beds were not described in detail by him. Immediately 

 below the town the beds are masked by debris ; but after passing 

 the mole there are fine sections several miles in length. The follow- 

 ing sections (figs. 1 & 2), which I took on the coast, about two miles 

 apart, give a fair representation of the general run of the beds. 



Sarmatic, or Passage-beds. — The lowest beds seen are stratified 

 limestones full of shells. The strata rise to about 10 feet above the 

 level of the sea ; and as they retain the same position for several 

 miles along the shore, they must be nearly, if not quite, horizontal. 

 Some of the beds are arenaceous ; and the topmost are much decom- 

 posed, so that the shells can be picked out from the matrix. The 

 commonest forms are Mactra podolica, Tapes gregaria, Cardium 

 plicatum, and C. obsoletum amongst the bivalves, and Bulla La- 

 jonlcairiana, Buccinum duplication, B. Verneuilli and Trochus podo- 

 ticus amongst the univalves. They are the " Passage-beds " of Mur- 

 chison, and the " sarmatische Schichten " of Suess. 



