1823.] the principal Mountain Chains of Europe. 15 



The Erzegeberge (forming the NW border of the Bohemian 

 basin) presents the same primitive rocks skirted by the transition 

 series. Its ridge supports in many places insulated basaltic 

 summits, which are also abundant on the Bohemian side, where 

 in the Mittelwald between the Erzegeberge and the Eger, they 

 repose on tertiary deposits containing lignite. Porphyritic rocks 

 overlying coal abound on the N of this chain as in the Thuringer- 

 wald. 



The Riesengeberge (a continuation of the Erzegeberge on the 

 opposite side of the Elbe, forming the north-eastern border of 

 the Bohemian basin) has a central granitic axis, skirted by 

 gneiss sometimes including micaslate, by clayslate, and lastly, 

 by transition rocks ; The gneissy zone is most extensive on 

 the north, and that of clayslate on the south, of the central 

 range. Beyond the valley of the Neisse, the continuation 

 of this chain (here principally composed of clayslate), assumes 

 the name of the Sudetengeberge, and ranging round the 

 district of Glatz, unites itself with the slaty ridges proceeding 

 from the Bohemerwald, thus completing the enclosure of the 

 Bohemian basin (which, as we shall hereafter see, is occupied by 

 the carboniferous series, new red sandstone, tertiary, and basal- 

 tic formations). The Valley of the Oder on the north, and of 

 Moravia on the south, separate these chains from those of the 

 prolongation of Alps towards the Carpathians ranging by 

 Presburg. 



(L.) Carpathian Mountains. 



These mountains range in a semicircle round Hungary from 

 Presburg, on the W, to the neighbourhood of Belgrade on the E; 

 the ancient rocks, however, are not exhibited on the surface 

 throughout the whole of this semicircle, there being an interval 

 near the middle of its course (above the sources of the river 

 Theiss) in which the older rocks only appear in patches bursting 

 through an overlying sandstone deposit. With this exception, 

 however, which does not amount to more than a sixth part of 

 the whole semicircular range, the older formations are uninter- 

 rupted. They present first a central granite, then granite, gneiss, 

 and micaslate, alternating together. 3. Micaslate and clayslate 

 containing granular limestone. 4. Serpentine diallage rock 

 (Euphotide) and greenstone porphyry. 5. Transition rocks. 



Having enclosed Transylvania by a rapid bend, the primitive 

 chain crosses the Danube below Belgrade. 



It then appears to extend itself to the S, turning round to the 

 E, and forming the chain of the Balkan or Mount Hannus. 



(M.) Mount Balkan or Hamus. 



I am not acquainted with any geological description of this 

 chain. Macmiehael, however, observes, in crossing it from 



