﻿106 



PROF. E. W. SKEATS ON THE 



[Feb. 1905, 



Sett Sass. 



No. 



*112 



107 



108 



CaC0 3 . 



Mg0O 3 . 



Per cent. 



Per cent. 



54-8 



45-2 



54-6 



44-2 



54-6 



44-1 



Insoluble residue. 

 Per cent. 



1-20 



1-26 



Not in place. 



Three specimens were collected from the northern - end of Sett 

 Sass. No. 112 was taken from a block fallen from the upper part 

 of the mass ; No. 107 from the upper, and No. 108 from the lower 

 part of the mass at the junction with the St. Cassian Limestone below. 



No. 

 110 



CaC0 3 . 1 MgC0 3 . 



Insol. res. 



Per cent. 1 Per cent. 





54-7 | 45-3 



... 



The Eichthofen Eeef. 



Eesidue is absent from Nos. 112 & 110, but present in fair 



quantity in Nos. 107 & 108. 

 The rocks are all dolomites of 

 theoretical composition. The 

 Eichthofen Eeef is a wedge- 

 shaped mass, apparently interbedded with the St. Cassian Limestone 

 which occurs below Sett Sass. 



St. Cassian Limestones from Sett Sass. 



Two analyses of St. Cassian Limestones from this district are 



included for comparison 

 Insol. res. w ith the dolomites. No. 



P tmce^ 109 WaS taken * T ° m the 

 6 . 4 Q rock lying between the 



base of the dolomite of 



Sett Sass and the Eichthofen Eeef; No. Ill from just below the 



Eichthofen Eeef. It will be seen that the limestones are only 



slightly dolomitized, that they are distinctly ferruginous, and that, 



while No. 109 is free from insoluble residue, No. Ill contains over 



6 per cent. 





CaC0 3 . 



MgC0 3 . 



Fe 2 3 . 



No. 



Per cent. 



Per cent. 



Per cent 



109... 



907 



6-0 



3-33 



111... 



781 



11-8 



373 



The Cortina District. 

 Col Crepa. 



Specimens Nos. 49 to 51 were collected, in descending order, from 



the western side, and Nos. 62 & 

 64 from the northern side of 

 Col Crepa near Cortina. This 

 hill consists of Schlern Dolomite 

 faulted on all sides against 

 St. Cassian and Wengen Beds. 

 It will be noticed that the rocks, 

 while highly dolomitic, are not theoretical dolomites, and that (with 

 the exception of No. 51) they are practically free from insoluble 

 residue. 



No. 

 49. 

 50. 

 51 . 

 62. 

 64 . 



CaC0 3 . 



MgC0 3 . 



Insol. res. 



Per cent. 



Per cent. 



Per cent. 



601 



39-9 





60-0 



400 





56-7 



42-8 



•46 



599 



401 



■013 



620 



38-0 



•02 



