go PF.NÏTI KSKOLA. M.-X. Kl. 



'I'lic cliiiopN Tdxciic is riliiiost colrjiii-lcss Of faiiiily grcf.-nish grc}'. Diallage- 

 parting after (loo) is j)r()miii( iil. 2 K -88^ measured with Klein's lens. 

 Assuming [i 1-70, this \riluc gives 2 V " - 48 '. Axial dispersion is hardly 

 noticeable. 



The reddish hrown hioiiic and, in smaller (juantities, the green horn- 

 blende occiii- only as grou])s of fringes and minute grains around the 

 garnet and pyio.xene. The iron ore is more independent, but its grains 

 show irregular shapes. 



Occasional grains of ortliorhonibic pyro.xene are associated with the 

 monoclinic pyroxene. 



The rounded garnets often are enclosed in the pyroxene, thus having 

 the appearance of that mineral earliest crystallized out. They are free 

 from inclusions. 



All the minerals display signs of strong mechanical deformation. The 

 plagioclase for the greater part has been granulated, and the central kernels 

 of the crystals still preserved show bent lamellae and undulator}- extinction. 

 As Goldschmidt already pointed out, (op. cit.) these phenomena, in the 

 Jotun rocks, are probably of a protoclastic character. 



The garnet-gabbro from Aardal is genetically related to the eclogite- 

 gabbro from Romsdalshorn. Here also different stages of mineral develop- 

 ment may be discerned. The prevalence of iron over magnesia was 

 favourable to the preservation of the garnet, and therefore we do not see 

 here any proofs of the garnet having become unstable, although it no doubt 

 at first crystallized in the eclogite facies. 



The garnet-bearing variety, according to private information by Prof. 

 Goldschmidt, occurs as a boundary variety in a gabbro mass. 



ECLOGITE AND GARNET IN THE LABRADORITE- 



ROCKS OF THE BERGEN REGION. 



Synopsis of the Labradorite-rock Series after C. F. Kolderup. 



The labradorite-rocks in the Bergen region were first dealt with by 

 C. F. Naumann' and later by Th. Miortdahl and M. Irgens- who already 

 characterized the eclogite occurring in connection with these rocks simply 

 as "a variety of the labradorite-rock, and no independent rock". 



' C. F. Naumann, Beiträge zur Kenntniss Norwegens, Leipzig 1824'. 



2 Th. Hiortdahl og M. Irgens, Geologiske Undersogelser i Bergens Omegn. Universitets- 

 program for andet halvaar 1862. 



