gS l'KNÏTI ESKOLA. M.-N. Kl.- 



around the py roxcnc arc .':f;mcti'n-.es not unlike the diopside-plagioclase 

 symplectite, though their stiucture is n cre irrtgular. On closer examinatirn, 

 however, we find here quite other minerals, and the alteration .of the gar- 

 net and ol the pyroxene have led to almost the same products. — As 

 Koldciuio points out, the alteration /ones contain, besides pale green 

 hornblende, niiicli chlorite, epidote and mica. The latter is in 

 part colourless, a niuscovite, but more generally a fainty pleochroic, 

 pale green mica that might be taken for chlorite but for its strong 

 birefringence. The same mica is also commonly niet with in the saussurite- 

 mass associated with zoisite. Amongst the alteration products I have, also^ 

 commonly observed margarite, known by its "micaceous" characters and 

 Y — a about o.oio. 



In terms of the facies theory this kind of alteration means that the 

 changes under consideration have proceeded in ihe greenschist facies and 

 not in the amphiboHte facies, as the alteration ot the eclogites in Nordfjord 

 and Møre. The rocks, after solidification, on their way towards the earth's 

 surface, have happily surpassed the middle depth-zone, the amphibolite 

 region, but still farther upwards been subject to differential movements and 

 stress action promoting' the change into, or nearly into, the greenschist 

 facies. 



Besides this g r e e n s c h i s t-kely phi te there are also frequent 

 examples of common am ph i bol i te-kely phi te. In a specimen of garnet- 

 labradorite-rcck from the Kismul Mine all the pyroxene has been com- 

 pletely replaced, and the garnet in large part, by different zones of pure 

 green hornblende. An incipient saussuritization has later left its impress 

 on the plagioclase, but has not affected the hornblende. 



Miiicralogical Varieties of dark Segregations. 



Concerning the dark segregations I have little to add to Kolderup's 

 description. Three kinds were represented among the specimens studied 

 by me: (i) Those of monoclinic pyroxene, with border-zones of gar- 

 net (specimens from Arnevaagen, near Bergen); (2) Segregations 

 composed of green hornblende, with border-zones of garnet (Alvaer- 

 st rommen); (3) Segregations composed of garnet, clinop3Toxene and 

 orthopyroxene without border- zones (specimens from several localities 

 on Holseno). 



The last-named kind of segregations alone deser\-es description in this 

 place, being one of the most interesting rocks studied bv nie. In one 

 of the specimens, such segregaticns are of the siz'e of the fist, but 

 probabl}' others of them are much larger. At all events, they, more than 

 the other kinds of inclusions mentioned present the aspect of a true rock, 

 and were that postulate omitted that an eclogite must contain clinopyroxene 



