THE DISTRICT OF SCHEMNITZ, HUNGARY. 315 



potherium, Machairodus, and Antilope, with species of Sits and Hy- 

 cena. The volcanic islands of Hungary must at this stage of their 

 history have been very similar in appearance to those of the Grecian 

 archipelago. 



That during this period of subsidence the basal wreck of the 

 Schemnitz cone underwent a vast amount of denudation we have the 

 clearest proofs ; the crater-ring was evidently breached at a number 

 of points, and " barrancos " formed leading into it, the sea being 

 thus permitted to enter it and to eat back the cliffs around it, with 

 the same kind of action that Lyell and Darwin have shown to be 

 taking place in the submerged volcanos of the Atlantic ; and in this 

 manner the extent of the vast " caldera " was probably greatly 

 increased. Around the flanks and in the centre of the ruined vol- 

 cano, deposits enclosing relics of the interesting fauna and flora of 

 the period were accumulated — beds with marine, brackish- water, 

 and freshwater shells alternating with lignites, formed by the 

 numerous vegetable remains carried down into the lagoons, and 

 with masses of tuffs ejected from the volcanic vents. 



It was during this condition of the volcano that the last eruptions 

 of the Schemnitz area took place ; and these were almost entirely 

 confined to the central lagoon occupying the crateral hollow of the 

 old volcano. The materials ejected during these later outbursts 

 consisted in the first instance of quartz-trachytes (liparites or rhy- 

 olites) with the beautiful varieties of perlitic rocks which we have 

 already referred to as having probably been formed for the most part 

 under water and not constituting true pumice. The eruption of these 

 highly acid rocks was followed by that of those of extreme basic 

 character — the basalts. At this period of its history the appearance 

 of the volcano of Schemnitz must have presented a most striking re- 

 semblance to that now exhibited by Santorin. The latter is a nearly 

 submerged and greatly ruined crateral ring, the interior of which is 

 occupied by the sea, in the midst of which a number of new and 

 smaller cones arc being gradually built up by the eruptions which 

 are taking place at the present day. In the Schemnitz caldera the 

 ejection of the rhyolitic lavas and tuffs was followed by that of the 

 basalts, and a number of cones were formed which gradually rose 

 above the surface of the central lagoon ; and thus the eruptions that 

 were at first submarine gradually became subaerial ones. By a 

 continuance of these outbursts, the depression of the central area 

 appears to have become eventually entirely filled up, and the sea ex- 

 cluded from it, the process being probably aided by a process of slow 

 upheaval which the whole district was gradually undergoing. 



It is impossible to pass by in silence the points of analogy in the 

 succession of the different lavas of the Tertiary Hungarian volcanos 

 and that of the more recent ones of the Lipari Islands *. In both 

 cases the ejected materials which have formed the great mass of the 

 volcanos, consist of rocks of composition intermediate between the 

 acid and the basic types ; and the eruption of these was followed, 



* See Geological Magazine, Decade ii. vol. ii. p. 00. 

 Q. J. G. S. No. 127. z 



