phalen] the rocks of nugsuaks peninsula -09 



the present time must only tend to obscure and to detract attention 

 from the main topic at issue. At any rate, with this idea in view, 

 it was decided to append a second chapter, devoted chiefly to the 

 discussion of the rock analyses and their interpretation in the light 

 of the work already alluded to. 



UMANAK ISLAND 



Granite (Cat. No. 75,480). — Directly back of the low-lying ex- 

 panse which has been described as stretching a mile back from the 

 coast^ there rises, to a height of 3700 feet, a typical nunatak, com- 

 posed of granite. An analysis of this granite, comprising the boss, 

 follows, and with it an analysis of graphic granite from Omeo, Vic- 

 toria, Australia, by A. W. Howitt. 



Analysis of Granite — Omeose 



(i) (2) 



SiO^ 76.03 70.91 



ALO3 12.02 15.32 



Fc' O3 69 trace 



Feb 68 — 



R%0 18 .07 



CaO 1.61 .58 



Na-.0 2.97 2.31 



K.O 5.72 10.07 



H.O 20 .51 



TiO. .28 — 



100.38 99-77 



Note.— I. Greenland granite, W. C. Phalen, analyst. 2. Graphic granite, 

 Omeo, Victoria, Australia, A. W. Howitt, analyst. Trans. Roy. Soc. Vic- 

 toria, XXIV, pt. II, p. 120, 1888. 



Composition in Terms of Standard Minerals 



(i) (2) 



Quartz 34-38 18.00 



Orthoclase 33-92 59-49 



Albite 24.63 19-39 



Anorthite 2.78 1.67 



Ilmenite 61 



Magnetite 93 — 



Diopside i-57 -66 



Wollastonite i-39 — 



H2O -^o .51 



100.41 99.72 



According to the quantitative scheme of classification the rock 

 works out to an omeose, a rock very high in silica and potash, 

 granitic in every respect. 



^ See page 186. 



