.8 



one is a coarse graphite schist^) which when examined 

 microscopically was found to contain besides graphite a 

 quantity of biotite, quartz, and plagioclase. Approaching 

 close to this rock is an eruptive rock (probably a dyke) which 

 when examined microscopically proves to belong to the same 

 class of eruptive dykes as those reported below from some 

 places around Cape Dan. It consists of a basic plagioclase 

 in thin, elongated prismatic columns, particularly fresh and un- 

 broken and showing a zonal structure; a greyish brown augite 

 in the shape of somewhat irregular grains; crystals of magne- 

 tite; and a fine, fibrous mass of laminae of a green mineral, 

 doubtless chloritic , with a rather strong double refraction. 

 Olivine also occurs along the cracks turned into a substance 

 resembling or identical with the above-mentioned. 



While, on the one hand, it is obvious that certain true 

 diabases, viz. in Sweden, forms of the so-called Ås by type, 

 are as well-preserved as the specimens in question, yet, on the 

 other hand, it must be acknowledged that they are almost iden- 

 tical with the basalts occurring in numerous beds and dykes 

 in the interior of Scoresby Sound, among which may be men- 

 tioned the intrusive beds of basaU in the Jura sandstone in 

 the South-Eastern part of Jameson Land; and on comparing 

 these rocks one cannot but conclude that the dykes in the 

 district of Angmagsalik are undoubtedly nearly contemporary 

 with the immense massive basalts on the more northerly coast. 



A similar rock occurs in the collection from the island 

 of Kumarmiut situated more to the south near Ingmikertok 

 (lat. 66° 45' N. and long. 36° 56' W.). The plagioclase, augite 

 and ore resemble those described above; and here as there 



') The graphite schist lies about NE. — SW. and dips 70° due NW. ; the 

 thickness is about 11 cm. The rocks are connected with the south side 

 of Ikerasak and consist alternately of crystalline schists and of a light- 

 coloured pegmatite gneiss (striped granite). The sides t)f the sound 

 show lofty sections of rock.s consisting of the same succes.^ions of layers. 



C. Kruuse. 



