600 MISS M. M. OGILVIE [mRS. GOEDOf] ON THE [Aug. 1 899, 



strata buckled below the peripheral shear-plane on the south of 

 Sella. 



Some thickness of Schlern Dolomite surmounts the Cassian strata 

 on the Campolungo Pass, and has the same strike and dip as these 

 strata. The dolomitic rock has been weathered into fantastic needles 

 and large irregular blocks, cleavage -slabs of the rock forming the 

 dominant structural feature, although in places the planes of strati- 

 fication ma^^ be clearly distinguished. Cleavage has taken place 

 parallel with the strike, and also in a north-and-south direction 

 (see fig. 21, p. 614). These intersecting sets of cleavage-})lanes give 

 evidence of an actual twist of the overfold at the Campolungo Pass. 



The Campolungo-Pass outcrop of Schlern Dolomite thins out south- 

 ward towards theBovaAlp, and is cut off" on the north. At the same 

 time, certain lenticular patches of Raibl strata are present at intervals 

 on the top of the Schlern-Dolomite streak. The most vividly 

 coloured and largest of these occurs on the mountain-slope imme- 

 diately west of the needles of Schlern Dolomite, and at a higher 

 level than the latter. 



Strata above the shear-plane (east side). — A moun- 

 tain-shelf composed of Schern Dolomite and Eaibl strata rises above 

 the Bova Alp, and the same horizons of rock continue throughout 

 the east side of Sella in the form of a diagonal north-north-easterly 

 and south-south-westerly anticlinal fold, with strata dipping eastward 

 and west\'^ard. Schlern Dolomite, with a strike north and south, dip- 

 ping 30° westward, and a slight easterly flexure, forms the prominent 

 rounded summit of Col di Stein and the shelving terrace of Plan de 

 Sass, north of Col di Stein. The upper surface both of the summit 

 and terrace is wavy, and the strata show frequent contortions. 

 Eaibl rocks are present at the top of the terrace in complete succes- 

 sion, conformably overlying Schlern Dolomite. Large blocks of Dach- 

 stein Limestone are strewn over the terrace, some of them containing 

 numerous specimens of Megalodon triqueter ; there is, however, no 

 Dachstein-rock in situ on the terrace. 



The strike of the rocks curves round on the terrace from north 

 and south to north-north-west and south-south-east in the upper 

 part, where the dip is inward, and to north-north-east and south- 

 south-west in the lower levels of the terrace, where the strata dip 

 outward. The strata are, in short, twisted in difi'erent directions. 

 The cleavage-planes cross each other in northerly and southerly and 

 north-westerly and south-easterly directions. 



The outward-dipping layers of Schlern Dolomite descend to the 

 grassy slopes between the Campolungo Pass and the Corvara Pass, 

 and meet there Cassian marls and limestones with a north-easterly 

 strike and a steep dip towards the terrace. 



Associated fold-fracture and strike-torsion. — I 

 have frequently heard the opinion expressed that the Eaibl patch 

 west of the Campolungo Pass is merely a slipped fragment from 

 the complete succession of Eaibl strata on the Pian de Sass terrace 

 above. But that by no means explains all the facts as they may be 

 observed in the neighbourhood of the Eova Alp and Pian de Sass. 



