310 Dr. M. M. Ogilvie Gordon — Monzoni and Upper Fassa. 



in the Monzoni mountain based upon the details of strike-cleavage 

 in the Campagnazza Meadowland and Monzoni. 



The Costabella downslip slice strikes N. 75°-80° W., the Cam- 

 pagnazza shear-slice strikes N. 65° E,, the Pellegrino thrust-slice 

 strikes N. 65°-80° W. These facts indicate that the proximal 

 crust-slices have adjusted themselves in the Campagnazza along 

 different strikes, the one being the differential correlative of the 

 other. But at Allochet the strike both of the Costabella and 

 Campagnazza crust-slices curves to the E.N.E.-W.S.W. direction, 

 and the monzonite rocks of Monzoni have this as their fundamental 

 strike, the dip-cleavages being towards the north-west at an angle 

 of ca. 50°, and towards the south-east at an angle of ca. 40°. The 

 E.N.E. and "W.N.W. strikes may both be suitably termed ' Asta ' 

 strikes, from the famous Cima d'Asta Massive in the Dolomites, 

 where Professor Suess first determined overthrust movement towards 

 the S.S.E. 



H 



Transverse section through the Costabella range (Middle Triassic limestone) ; the 

 Campagnazza Meadowland (Lower Triassic mixed deposits and fault-fragments 

 of Permian strata) ; the slopes of Pellegrino Valley (Permian strata {Pm.) and 

 Quartz Porphyry (Q.F.)) ; ff, 'Asta' faults; E.W., old east-west fault; 

 s s, porphyi'ite sUl and dyke system ascending faults, cleavage-planes, and 

 bedding-planes. 



Tn my previous papers I have demonstrated that these correlative 

 strikes developed in consequence of the superposition of the Peri- 

 Adriatic movements upon the regional East Alpine movement, and 

 this explanation is fully borne out in the Campagnazza. The 

 east- west fault north of Monzoni and the Campagnazza is, according 

 to my researches, an old synclinal fault between two fundamental 

 East Alpine anticlines, that of the original Pellegrino anticline on 

 the south of the fault, and on the north of it the anticline which 

 I shall term the Contrin anticline, from its favourable exposure on 

 the Contrin Alpe north of the Costabella range. 



The north fault-limit of Monzoni with east-west direction has 

 in previous literature gone by the name of the 'eruptive fissure,' 

 and probably the direction of this fault gave the erroneous impression 

 that the monzonite had a parallel strike. But the monzonite rock 

 both here and in the Predazzo area, a little to the south-west of 

 Monzoni, strikes E.N.E.-W.S.W., and as will appear from what 

 follows, the original intrusion of monzonitic magma was a continuous 



