346 



T. BELT ON THE STEPPES OE SOUTHERN RUSSIA. 



surface modification of the fine diluvial clay, produced by the pene- 

 tration of roots carrying down organic matter. 



About eleven miles north-east from Taganrog, at the village of 

 Siniafka, the following section (fig. 3) is exposed near the railway 

 from Taganrog to Ilostof. 



Fig. 3. — Section near Siniafka, 11 miles N.E. of Taganrog. 



I31ack soil 

 Diluvium 



10 



Fluviatile beds .... 



Older SteppeLime- ) 

 stone or Con- C 1° 

 gerian beds. ' 



Farmatic or Pas- I jg 

 sage-beds. J 



Covered with talus 



Alluvium 

 of Don. 



The lowest strata seen at this place are thinly laminated beds of 

 dark sandy silt, containing impressions of Tapes gregaria and a few 

 other shells belonging to the Sarmatic or Passage-beds. 



Above these lie about 15 feet of limestone, composed, in a great 

 measure, of the shells of a species of Dreissena. Some of the lowest 

 beds were entirely composed of these shells, held together by a little 

 calcareous cement. The upper beds are sometimes concretionary, 

 and resemble in appearance some of the magnesian limestones of the 

 north of England. These limestones are the Older Steppe Lime- 

 stone of Murchison, and the Congerian or Ingersdorf strata of the 

 Austro -Hungarian geologists. 



Above the limestone lies about 10 feet of yellow sand, which 

 becomes a little loamy upwards. At the base I found fragments of 

 limestone and pebbles of quartz and quartzose sandstone. I saw no 

 shells ; but fragments of bones and of tusks of the Mammoth were 

 not uncommon. I picked several pieces out of the undisturbed 

 sand ; and the workmen employed in getting ballast for the railway 

 had thrown on one side many others. 



In ascending the estuary of the Don a similar succession of beds 

 is often exposed, though one or more members of it are frequently 

 absent through denudation ; but everywhere the diluvium caps the 

 series, resting sometimes on the Congerian strata, and sometimes on 

 the Sarmatic beds. I sketched the following section (fig. 4) near 

 Nova Tcherkask, the chief town of the Don Cossacks. 



The cliff near Nova Tcherkask is mostly formed of the Sarmatic 

 and Congerian strata, and there is a capping of only about 18 feet 

 of black earth, diluvium, and sand; but the diluvium thickens 



