A glacial deposit near Christiania. 7 



syenite-porphyry and adding two hundred and fifty-six speci- 

 mens of the central type-rock, we then get a total sum of 

 three hundred and twenty-one individual specimens. 



Then comes a rather heterogenic group embracing dyke 

 rocks of very different types. Here we see five specimens 

 of a light-coloured rock, very fine in grain, and probably 

 being a keratophyre, a bostonite or a mænaite. One single 

 specimen of true syenite-porphyry is also seen. Then we 

 meet with a group of dark-coloured rocks, very fine in grain, 

 and being of a basic type, diabases. Out of those rocks we 

 count thirteen specimens. Besides, we observe one speci- 

 men of a greyish diabase-porphyrite. Summing up those 

 dyke-rocks we find twenty specimens. 



Then we meet with some rare and higly interesting 

 rocks. We observe one single specimen of the brecciated 

 augite-porphyrite of the region of the Lake of Alunsjøen, 

 characterized as is this rock by greenish epidote. We also 

 observe one single bit of another interesting rock-specimen, 

 the breccia or fault-rock met with along the line of disloca- 

 tion of Ekeberg, in the eastern suburb of Christiania. I also 

 found one single specimen of a grey norite-rock, tinged with 

 a reddish colour. I have met with quite the same type as 

 constituting the firm rock near the Glacier of Sletmarkhø in 

 Jotunheimen, but I dare not say, if the same rock is not 

 also found in other places of central Norway. 



Placing in a table the percentage of the different rocks 

 forming the blocks and stones of the gravel we get the 

 following list: 



Archæan schistose rocks 15,05 



Archæan igneous rocks 1,39 



Sedimentary rocks 12,67 



Contact-metomorphosed rocks .... 2,77 



