T. BELT ON THE STEPPES OF SOUTHERN RUSSIA. 849 



To the west there is a descent into the valley of a tributary of the 

 Dniester, on the other side of which is the Austrian frontier town of 

 Podwolochisk. Westward from Podwolochisk the country gradually 

 rises, and beds of limestone containing marine shells occasionally 

 come to the surface, whilst the hollows between these knolls of the 

 older rocks are filled with diluvial clay. The diagram, fig. 6 (p. 850), 

 shows the position of the surface-beds at Wolochisk and Podwo- 

 lochisk. 



In rising from the alluvial plain at Podwolochisk westward some 

 deep railway-cuttings had been made ; and these were being widened 

 at the time of my visit, affording me an excellent opportunity of 

 examining the diluvial beds. At the point marked * in the dia- 

 gram I obtained the section, fig. 7 (p. 850). 



The lowest bed of the diluvium seen here (marked 3 in fig. 7) is 

 a yellowish brown fine clay, rather sand}', and breaking into irregular 

 flakes, as if the pressure of the beds above had given to it a sort 

 of slaty structure. Shells of Helix hispida, Succinea oblonga, and 

 Pupa marginata were scattered through the upper part of the stra- 

 tum. Above this lies about 20 feet of rather sandy clay, with obscure 

 signs of stratification. I could find no shells in this clay ; but this 

 part of the section was much hidden by soil slipped down from 

 above. 



The topmost bed of the diluvium is composed of about 10 feet of 

 yellowish-grey unstratified calcareous clay. Shells are abundantly 

 scattered through it, the most common being Succinea oblonga and 

 Pupa marginata. I also gathered Helix hispida, H. minuta, and 

 H. ericetorum, var. minuta. It also contains fragments of Miocene 

 shells and angular pieces of limestone. 



The resemblance of these clays to the beds of the Rhine and the 

 Danube, both in their composition and fossil contents, is most 

 remarkable. There is no question of this deposit being the diluvium 

 of the south of Russia ; and,[as I have already mentioned, it can be 

 followed continuously, excepting where cut through by the larger 

 rivers, all the way to Karkov. Westward from Podwolochisk, 

 through the province of Galicia, the same clay covers most of the 

 country to a height at least of 1200 feet above the sea. Near 

 Zloczou the black earth rests directly above shaly debris, and the 

 country loses its steppe-like appearance, and is more broken up into 

 hills and valleys. 



In November 1875, I tried to trace the diluvium northwards 

 from Karkov to its junction with or change into the northern drift 

 that covers the north of Russia to similar heights as the diluvium 

 further south. I found the country covered with diluvial clay all 

 the way to the city of Orel, on one of the tributaries of the Oka, 

 and near the top of the water-shed between that river and the 

 Dnieper. At Orel the low hills bounding the valley are all 

 covered with from 10 to 30 feet of unstratified yellowish brown 

 clay, containing calcareous concretions; and here I got the first 

 indications of the northern drift in a few pebbles of quartzite 

 scattered through the clay. 



