420 Geological Society. 



may combine to form characteristic torsion-curves. The author 

 regards the longitudinal and diagonal faults as constituting one 

 system. Each portion on one side of the anticlinal form of the 

 system has its reciprocal on the other side. The Spitz Kofi syncline 

 on the north is the reciprocal of that of Sella on the south, the 

 Langkofl on the south-west of that of Sass Songe on the north-east, 

 and so on. 



The anticlinal area of the Buchenstein Yalley is next described. 

 Here we have a torsion-system similar to that of the Groden Pass, 

 and made up of similar elements ; but the western portion of the 

 anticlinal is much compressed and displaced. Opposing areas of 

 depression are also found here, that of Sella and Sett Sass on the 

 north being reciprocated by that of the Marmolata on the south, and 

 soon. The porphyrite-sills have here been mainly injected into the 

 knee-bends of the northern wing of the anticlinal form, but igneous 

 injections and contact-phenomena are also met with in some of the 

 transverse faults. 



A full description is given of the sequence and stratigraphy in the 

 Sella massive — once regarded by some authorities as a Triassic 

 coral-reef. This is an ellipsoidal synclinal area with X.X.E. and 

 S.S.AV. axes twisted to north-east and south-west. Peripheral over- 

 thrusts have taken place outward from the massive, in such a way 

 as to buckle up the rocks like a broad-topped fan -structure, and these 

 overthrusts are traced by the author completely round the massive. 

 A central infold of Jurassic strata occurs on the plateau, where the 

 Upper Trias has been overthrust inwards on three sides of the infold. 

 The author next passes in review the results obtained in the area 

 of Sett Sass, etc. and shows how they all present corresponding 

 tectonic phenomena. 



The district thus studied in detail by the author forms a typical 

 unit in the structural features of the Dolomite region. It is cut off 

 to the eastward by the limiting fault (north-and-south N of Sasso 

 de Stria, and to the westward by the parallel fault of Sella Joch. 

 These are definite confines, which limit a four-sided area, influenced 

 by the Groden Pass torsion-system on the north and the Buchenstein 

 Valley system on the south. The limits of this four-sided figure 

 include a compound area of depression (formed by the Sella and Sett 

 Sass synclinals) traversed by the diagonal Campolungo buckle. 

 4 The area displays in a marked degree the phenomena of interference 

 cross-faults cutting a series of peripheral overthrusts round the 

 synclines, and parallel flexure faults between the anticlinal buckles 

 and the synclinal axes/ 



In conclusion, the author applies her results to the interpretation 

 of the complexities of the Judicarian-Asta region of the Dolomites 

 in general, aud also to the explanation of the characteristic 

 structural forms of the Alpine system as a whole. 



