PETTKO ON SCHEMNITZ. 63 
from copious warm springs in the interior of the crater, of which the 
thermal waters of Glashiitten and Eisenbach are the feeble remains. 
The Gran was compelled to force a way through the elevation- 
crater itself. The river broke through the ring above the village of 
Jalna, and formed in the interior, probably for a long period, a lake in 
which the sandstone containing brown coal was deposited, until it 
again found a way out at Konigsberg. It divides the crater into two 
halves, and has thus contributed to render its true character so very 
difficult to be recognised. 
It is remarkable that the laws established by Beudant for the dis- 
position of the trachytic rocks are in perfect harmony with this new. 
view. He says that the trachyte everywhere rises to the greatest 
elevations, and forms as it were the kernel on which, with gradually 
decreasing height, the porphyry, pearlstone and millstone are depo- 
sited. It is evident that he considered the individual projecting 
members of the trachyte ring as so many central points, from which 
he descended towards the Gran in the interior of the crater. A further 
symmetry of disposition arose from the occurrence of the volcanic tufa 
on both sides of the trachyte, this rock in reality occupying extensive 
tracts, not only in the interior of the crater, but also on its exterior 
declivities. 
In reference to the geological age of the Schemnitz veins, there are 
especially three circumstances from which this may be pretty distinctly 
known ; these are the epoch of the elevation which caused the fissures, 
then the formations which the veins do, and lastly those which they 
do not traverse. 
1. The veins at Schemnitz are nearly parallel to each other, and 
also to the high ridge of gneiss which runs across from the Glashiitten 
valley to that of Hodritsch, and follows almost the inner border of 
the rmg of trachyte mountains. It is not improbable that the eleva- 
tion of this ridge has also caused the formation of the fissures. On 
the gneiss, along with subordinate beds of quartz-rock, clay-slate and 
sandstone, rests a compact limestone of great extent and thickness, 
which is again covered by a limestone conglomerate. In the latter, 
at Eisenbach, blocks occur, consisting almost entirely of nummulites, 
and also nummulites dispersed singly im an arenaceo-calcareous basis. 
_ These bodies are no longer regarded as exclusively tertiary fossils, but 
they occur here in a deposit which is not their original place, and 
which may therefore be tertiary, even although the nummulites may 
have lived in the more recent secondary epochs. Now these strata 
are themselves elevated, and consequently the elevation, and hence also 
the formation of the fissures must have taken place after the depo- 
sition of the tertiary conglomerate, and thus at all events not earlier 
than the tertiary period, probably in its middle division. This cir- 
cumstance may even fix the age of the great elevation-crater itself. 
2. The rocks traversed by the Schemnitz mineral veins are green- 
stone and greenstone tufa. There is nothing to show that the green- 
stone of this district is older than the connected trachyte, whilst the 
frequent. transitions of the two rocks into each other, and their com- 
mon local disposition, forming together the great ring-shaped moun- 
