Glacial Kangaroo Gidbj. 38 F 



shiiit. All these gentleintn were, at the time the analyses were made, 

 atlvunced students in the Geological department of the University. 

 Their results are as follow : — 



A. — Analysis of volcanic fragniental rock from main shaft, jjy T. 

 H. Plante, B.Sc. ; alkalies in above by E. 0. Thiele. M.Sc. 



B. — Analysis of nionchitiuite dyke, penetrating deixisit in 

 Kangaroo Gully, by H. C. Richards. M.Sc. 



(J. — Analysis of Ordovician fragment, from Jenkins and Bielski's 

 shaft, by H. C. Richards, M.Sc. 



D. — Analysis of monchiquite, fioni Central Red, White and 

 Blue mine. Sheepshead line, by F. L. Stillwell, M.Sc. (Quoted 

 from Proc. Roy. Soc. Vict.. Vol. xxv. (new series). Part i.. li)12. 



p. 1.; 



Total - 100.64 101.67 99.66 100.47 



Certain comments on the analyses are necessary. In tlie first 

 place both A and B are very altered i-ocks. This may be legarded 

 as explaining the high-water content (mostly in the serpentine), and 

 the amount of CO^ present in the rock. As the locks were sfv 

 altered, all the iron present was determined as Fe^Og. Allowing 

 for these points, it will be noticed that there is a close resemblance 

 in the analyses of the monchiquite dyke from Kangaroo Gully 

 analysed by Mr. Richards, and that of the Central Red White and 

 Blue mine analysed later by Mr. Stillwell. 



The comparison between analyses A and B brings out some 

 interesting points, and one very puzzling one. The percentages of 

 silica, titanium oxide, and ferric oxide in the two rocks are so 

 similar as to leave no doubt that the rocks were originallv essen- 



