556 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [JunO 17, 



The disturbance of the sand would be less or greater, according as 

 the face of the granite was more or less parallel with the line of 

 motion ; for, supposing the two to coincide at any point along the 

 line, then the latter would merely slide, as it were, along the face of 

 the sandy layers, and that of the older strata, causing little or no 

 disturbance ; should, however, the face of the granite be more vertical 

 than the line of movement, then the effect would be a lifting up and 

 lateral displacement of the deposit lying against it. 



An entire absence of any signs of disturbance in the Quader, near 

 the border, could, however, be possible only in the case that its 

 induration commenced subsequently to the period of upheaval of the 

 granite; but that this induration was completed before that rock 

 reached its present relative elevation, is proved by the fact that the 

 sandstone presents all along its border evident and unmistakeable 

 indications of having been subjected to lateral pressure. 



This latter fact is of great significance, as going far towards 

 accounting for the crushed condition and inclination of the strata 

 which lie against those parts of the granite border which are per- 

 pendicular, or nearly so, and the almost total absence of these phe- 

 nomena at Hohnstein and other parts, where the contact-line dips at 

 a small angle from the sandstone. The above- stated fact will also 

 go far towards accounting for the presence (at the surface) of the 

 Jurassic rocks at Hohnstein and Hinterhumsdorf, and their absence 

 at all other parts along the line. I will proceed to state the grounds 

 which my opinion with regard to this fact is based. 



At those places where the calcareous rock is found, the granite 

 overlies the newer rocks to a considerable extent, while at most other 

 parts of the line the granite and sandstone abut against each other 

 almost vertically, to the height of, at least, 500 feet. It would thus 

 seem probable that, prior to the commencement of the deposition of 

 the latter, a long range of cliffs may have formed the northern 

 shore of the Jurassic sea at this place, against which the strata of 

 that period were deposited. 



If this be admitted, three different epochs may be supposed to be 

 represented at a part of the border where the transverse direction of 

 the fissure approximates, more or less, to that of the moving force, 

 and the same epochs at a part where the fracture is vertical*. 



The continued advance of the granitic mass through the loose sand 

 at some parts of the border would have no other effect than that 

 of increasing in some degree the compactness of the latter in the 

 immediate vicinity of the disturbing agent ; but from the moment 

 that the Quader had become comjpletely indurated throughout its 

 depth, the case would be altered entirely ; the latter would now be 

 crushed back, and the ends of the strata in contact with the granite 

 would be lifted up through the whole extent of the subsequent 

 upheaval. 



At those parts, however, where the granite overlaps the strata, 

 they would be very slightly disturbed ; the granite would slide over 



* I consider the force to have been exerted in a horizontal and north and 

 south direction. 



