Yol. 55.] THE TOESION-STEUCTURE OE THE DOLOMITES. 615 



converse curves and oppositely radiating faults on the eastern side 

 of Sella has been pointed out above (p. 604). 



Pralongia Pan It. — The next diagonal fault that I determined 

 on the Pralongia ridge is the Pralongia Fault, which divides a 

 central portion of the ridge, including the highest point (2182 metres), 

 from a western wing, where a cross stands upon a slightly lower 

 summit (2141 metres). The western wing is thrown down, and 

 large blocks and standing pieces of the highest thickly-bedded 

 Cassian limestones are jDreserved on it; whereas the fossiliferous 

 marls representing an older palseontological zone than these limestones 

 are exposed on the high central segments at Stuores. 



This Pralongia Pault may be traced northward along a line of 

 landslips as far as Corisell on the right bank of the Sore stream. 

 There it meets the eastern extremity of the southerly limiting-fault 

 of the Groden-Pass Anticline. Traced southward, the Pralongia 

 Fault causes marked disturbance in the strata of the southern 

 slopes at the 2000-metre and 1900-metre contour-lines. It is 

 continued through the overthrusts of Cherz Hill and across the 

 Buchenstein Valley to the Soraruaz area, whence it curves towards 

 Sasso di Mezzodi. This fault throughout has a downthrow to the 

 west. 



Stuores bundle of diagonal faults. — Another diagonal 

 fault cuts the Pralongia ridge, separating the central part with 

 its summit at 2182 metres from an eastern wing with its summit 

 at 2172 metres. Downthrow is to the east; hence the central 

 part of the Pralongia ridge corresponds to a diagonal 

 north - north - east and south- south -west arch with 

 flexure-faults on the opposite sides. This fault is a 

 branch from the more important diagonal fault which limits the 

 Stuores meadows against the western side of Sett Sass, with con- 

 siderable downthrow to the east. Between these two faults others 

 are present with similar effect, converging towards the north of 

 the Stuores meadows. The bundle of Stuores faults intersects the 

 southern overthrusts, and the latter curve at the area of intersection 

 from a west-north-westerly and east-south-easterly to a west-south- 

 westerly and east-north-easterly direction. The analogy between 

 the Stuores bundle and the Bova-Alp bundle of diagonal faults 

 (p. 604) will be at once apparent. 



The chief fault of the bundle between Stuores and Sett Sass 

 is continued northward along the western side of the Kreuz-Kofl. 

 dolomite-mountains.^ The main Stuores Fault marks as great a 

 downthrow of the strata on the east side o£ the Pralongia meadows 

 as that which has taken place on the west side, where a west-south- 

 west and east -north -east curved torsion -fault limits the Langs- 

 da-Fiir Anticline against the syncline of Siadu, and in both cases 

 the downthrow is eastward. 



These two faults form the two sides of a triangle whose wide base 

 is formed by the uptilted "Wengen strata of Campolungo and Cherz 



^ See my paper in Quart. Journ. Geol. Soo. vol. xlix (1893) pp. 64-66, and 

 Eotbpletz, ' Geol. Q.uerschnitt durch die Ost-Alpen,' 1894, p. 57. 



