92 



PENTTI ESKOLA. M.-N. Kl. 



Mol. iiiiiiiljcr 



797 

 12 



74 

 5^ 



75 

 321 

 270 



26 

 3 



100.14 



The most peculiar characteristic of this pyroxene is its high content 

 of alumina'. 



Following' two analyses of garnet- and pyroxene-bearing labradorite- 

 rocks (p. 36) may here be reprinted. I Sebo, Rado (by Lillejordj II Els- 

 fjord, Holseno (Hiortdahl and Irgens, op. cit. p. 21). 



The segregations of the dark minerals usually have lenticular shapes, 

 though irregular forms also occur. The lenticular structure is thought to 

 be a consequence of stress immediately before and during the consolidation. 

 Zonal arrangement sometimes occurs, the garnet forming the outer zone 

 around kernels mainly composed of the clinopyroxene. This arrangement, 

 however, is not common. (As we have seen, it is the regular case in the 

 labradorite-rocks in Sogn). More often garnet and pyroxene have been 



' Hiortdahl and Irgens, op. cit. p. 23, quote an imperfect analysis of diallage from coarse- 

 grained saussurite-gabbro, showing 49.52 SiO.^, 9.40 AI0O3, 10.70 FeaOa and 13.22 CaO. 



