16 Rev. W. D. Cuui/beare on a Geological Map, c\c. [Jaj<. 



Gablova to Shipka, that the strata on the N are generally calca- 

 reous, and the summit a blue or variegated marble ; but on the 

 descent, the rocks change to a hard argillaceous schist, abound- 

 ing in large veins of quartz. 



On the S of the Crimea is a tract of slate which may be a pro- 

 longation of this chain. 



(N.) The Range of Caucasus. 

 This, though beyond the limits of Europe, is necessarily 

 included in our present survey, being placed exactly on the pro- 

 longation of the line of Mount Balkan, and of the slaty tract 

 of the Crimea, of which it, therefore, appears to be the con- 

 tinuation, forming with it the southern border of the great 

 European basin. It is said to exhibit the usual primitive and 

 transition rocks skirted by compact limestone, and to exhibit 

 near its centre some overlying summits of floetz trap. 



(O.) Granite Plains of the Dnieper. 



These appear to constitute a group of primitive rocks protrud- 

 ing through the secondary and tertiary deposits of the great 

 basin : granite principally prevails, and the country is characte- 

 rised by the unusual circumstance, that although of primitive 

 structure, it is yet low, and, except where furrowed by the valleys 

 of the rivers traversing it, level. 



(P.) The Ural Chain. 

 The great European basin is open through a wide interval, 

 destitute of any primitive barrier towards the Caspian and Aral. 

 Whether any primitive zone exists behind these inland seas, or 

 how far the secondary deposits extend in this direction into Asia, 

 is unknown ; but on the NE, the Ural Mountains on the con- 

 fines of Europe and Asia again present a primitive border, exhi- 

 biting, according to Pallas, the usual central and collateral zones 

 of ancient mountain chains. It seems probable, but has not, I 

 believe, been ascertained, that the primitive rocks of Finland on 

 the north of the great basin extend along the shores of the 

 White Sea till they join the northern extremity of the Ural 

 chain, thus completing the primitive margin of the basin on that 

 side. 



{To be continued.) 



