Yol. 55.] TOESION-STRTJCTUEE OF THE DOLOMITES. 625 



overthrusts have taken place towards the north ; the other is the 

 torsion of the strike in a north-westerly and south-easterly direc- 

 tion. 



With regard to the northward overthrusts, the Diirrenstein 

 area resembles the Groden-Yalley and Seis-Alp area farther west. 

 Both areas are proximal to the schists of the Central Alps. The 

 inclined faults therefore hade away from the main anticline of the 

 Alps, so far as it is represented by the flanking schists. This is 

 quite in accord with my experience within the Dolomites — the 

 inclined planes hade away from torsion-buckles and 

 towards the chief synclinal basins within the areas 

 specially examined. 



With regard to the south-easterly torsion of the strike at 

 Diirrenstein, it corresponds with the general torsion which the 

 district of the Dolomites undergoes in the neighbour- 

 hood of the Sexten Valley. It is explained as a strike 

 compensatory to, and co-ordinated with, the crust-torsion in the 

 direction of the north-north-western and south-south-eastern arches 

 of the Groden and Enneberg area. 



YI. Application of the Peinciples of Toesion in the Dolomites 



AND IN THE JuDICAEIAN-AsTA EeOION. 



Correlation of anticlines and synclines. — So far as 

 the observations of the present author go, there is one general law 

 which governs the inclination of the fault-planes in the torsion- 

 structure of the Dolomites. Whether overthrust-planes or normal 

 fault-planes, if they are parallel with the strike of the rocks, 

 they incline towards the areas of subsidence in the particular 

 localities. 



Hence at Diirrenstein and the Prags margin the inclination of 

 the fault-planes is south and south-west towards the broad synclinal 

 area of Dachstein Dolomite, comprising the Eothwand, Pfanes, 

 Tofana, and Cristallo groups. Round the southern curve of the 

 same synclinal area, my observations in the Falzarego and Cortina 

 district showed that the fault-planes incline northward and north- 

 westward. 



Again , it has been found in Enneberg that the%j hief anticlines 

 have distinct reference to the particular synclines 

 north of them. The knee-bend flexures facing south are the 

 most strongly compressed. Overthrust-fractures have occurred, 

 while torsion has, at the same time, produced a fan of obliquely- 

 set anticlinal slices at varying angles of obliquity to the original 

 anticlinal axis. Corresponding phenomena have taken place where 

 return knee-bends formed facing the north, and were twisted in the 

 diagonally opposite direction. The squeezed and shattered anti- 

 clines are pierced by intrusive rocks, for the most part injected along 

 fault-planes. 



The Groden-Pass Anticline has the Spitz-Kofl and Sass-Songe 

 Q. J. G. S. No. 219. 2 s 



