96 



I'KXTTI KSKOI.A. 



M.-N. Kl. 



The plagifx'lasc in tliis rock shows _[_ PM extinction angles (>( 22 

 cofres];)onding- to Ab^,,. 



Other constituents are garnet and clinopyroxenc, the latter turbid 

 iVoni pigmentary substances and pale \iolet in colour, but it does not 

 show any notable axial dispersion. It is surrounded by narrow zones of 

 radiating fibrous hornblende, pale green in colour. The garnet locally has 

 similar though much narrower border-zones (kelyphite). 



Another specimen from Radø is a gabbro, also containing scapolite. 

 Garnet occurs here as large crystals including rounded grains of intenseh" 

 green though non-pleochroic augite which is also abundant as a coarse- 







Fig. 14. Strings ot garnet and dark inclusions (of clinopyroxenei with boundar\'-zones of 

 garnet in the labradorite-rock from the Bergen-region. 



grained mass with the plagioclase. The pyroxene is surrounded by zones 

 of homoaxial hornblende. When bordering against the plagioclase that is 

 an andesine (Abg^), much saussuritized, the hornblende is surrounded by- 

 zones of epidote in myrmekite-like intergrowth with a colourless mineral 

 which I did not succeed in determining. It is not in parallel orientation with 

 the adjacent plagioclase and has a considerably lower refraction than the 

 latter. From these facts and from analogy to the quartz-epidote-myrmekite 

 formerly observed by me in the rocks from Sviatoy Noss in Transbaikalia ' 

 I would suppose it to be quaitz. 



In the specimen from Alvaerstrommen there are frequent crystals of 

 garnet in plagioclase (Abgj), forming the main part of the rock. In the 

 plagioclase also are enclosed rounded crystals oi' pyroxene and scapolite. 

 A dark, sharply bounded veinlet, one centimeter in its thickest portion, 

 intersects the rock in the manner of a dike. It is mafnly composed of 



' P. Eskola, On the Igneous Rocks of Sviatoy Noss in Transbaikalia. Ufversikt av Finska 

 Vet.-Soc. Förh. XLIII, 1921, p. 66. 



