560 MISS M. M. OGILVIE [mRS. GORDON] ON THE [Aug. 1 899, 



34. The Torsion- Strttcture of the Dolomites. By Maria M. 

 Ogilvie [Mrs. Gordon], D.Sc. (Communicated by Prof. W. 

 W. Watts, M.A., Sec. G.S. Eead December 21st, 1898.) 



[Plate XL— Map.] 



Contents. 



Page 



I. Introductory Eemarks 560 



II. The Anticline of the Grodeii Pass 566 



III. The Anticline of the Buchenstein Valley .583 



IV. The Sella Massive 590 



V. Sett Sass and Pralongia 613 



VI. Application of the Principles of Torsion in the 



Dolomites and in the Judicarian-Asta Region 625 



I. Introductory Eemarks. 



The Sella Massive at the time when I examined it (1891- 

 1893) was one of the least visited of the Dolomite-mountains. 

 Its remoteness from the main tourist-routes was the chief draw- 

 back to popularity. But, in 1894, a new driving-road was opened 

 between Bruneck in the Puster Valley and Corvara in Enneberg 

 (a village at the foot of the Groden Pass and the Sella Massive). 

 A shelter-hut was also built on the mountain-terrace below the 

 Boe summit, and has since been satisfactorily conducted under the 

 auspices of the Bamberg section of the German and Austrian 

 Alpine Club. Thus, when I revisited the country in the season of 

 1898, I found that Enneberg and the Sella Massive had been 

 brought well within the sphere of ordinary tourist intercourse, and 

 that the physical difficulties of the long marches and ascents had 

 been very materially reduced. 



An historical epitome of the Geological Literature respecting 

 the ^Dolomites' was given in my first paper on the subject, pub- 

 lished in February 1893.^ It will be sufficient here to note briefly 

 the facts and opinions arrived at by geologists previous to the 

 reading of the present paper, grouping them generally according 

 as they deal, on the one hand with the stratigraphical, and on the 

 other hand with the tectonic side of the question. 



Stratigraphical. — The general succession of the Triassic rocks 

 as laid down by Baron E. von llichthofen ^ for the region of the 

 Dolomites is familiar to most geologists. The various members of 

 the sequence occur in the following (ascending) order : — 



(A) The Lower Trias or Werfen Series, subdivided locally into Seia 

 Limestone and Campil Sandstone, with characteristic fossils. 



(B) The Middle Trias or Muschelkalk Series, embracing a lower 

 and more calcareous and fossiliferous horizon, and a higher and more 



^ M. M. Ogilvie, ' Contributions to the Geology of the Werigen & St. Caasian 

 Strata in Southern Tyrol,' Quart. Journ. Geol. Soc. vol. xlix (1893) pp. 1-78. 



2 •GeognostischeBeschreibung der Umgegend von Predazzo, St. Cassian etc.,' 

 Gotha, 1860. 



