208 



It cannot be concluded with any certainty that all the rocks 

 here described are connected, but their appearance as well as 

 their character makes it highly probable. We have then a 

 peculiar series, intimately connected by transitions, alternating 

 between very acid up to ultrabasic formations, but all distinguished 

 by certain minéralogie peculiarities — among other things the 

 common occurrence of biotite, often as large phenocrysts, com- 

 pletely transformed into chlorite — and by chemical analogies, 

 in that all are evidently rocks that are rich in alkali. We have 

 here probably a strongly differentiated effusive analogy to the 

 aegirine-syenite from C. Parry ^) described by Bäckström. 



As to the age of the rocks we only know that, as has 

 already been shown, the conglomerate at G. Brown, which is 

 presumably of paleozoic age or belongs to the oldest triassic, 

 contains boulders which seem to correspond to the medium 

 acid forms described above. On the other hand, they are 

 younger than the С Fletcher beds, which must, hov^'ever, also 

 derive from the paleozoic age. During what epoch of that 

 period the eruption took place cannot be determined at present. 



2. Alnoitic rocks from the Hurry Inlet coast of Liverpool Land. 



As has been already mentioned. Bäckström, from a block 

 found on the Fame Islands, described as monchiquite a dark 

 rock with large porphyritic hexagonal biotite slabs, brown horn- 

 blende and violet-red augite, together with a ground-mass of 

 the same minerals embedded in a colourless, almost isotropic 

 mass which has been interpreted as nepheline. He also calls 

 attention to the really striking resemblance to the alnöite from 

 Alnö, from which, however, the specimen examined differs in 

 that melilite, olivine and perowskite are wanting. 



I came across the same rock in situ right opposite the 



') A block of a grey aegirine-syenite rock was found by me on the shore 

 of Jameson Land a good way inside Scoresby Sund. Similar rocks, 

 consequently, seem to occur in several areas along this coast. 



