Report on the Rocl^-Specwiens. 



327 



The red glassy scoriaceoiis hornl)lende-basalt at Cape Adare 

 was seen by Mr. Bernacclii to be traversed l)y small dykes 

 of a black basalt showing columnar structure (see fig. below). This 

 V)asalt is more coarsely-grained than the hornblende-basalt, and 

 consists of a medium -grained aggregate of felspar-laths and pale 

 purple augites with only a little magnetite and no interstitial glass. 



Other specimens from the neighbourhood of Cape Adare show 

 numerous and fairly large phenocrysts of clear olivine and pleochroic 



BASALT-DYKE AT CAPE ADARE. 



(^Froin a Photugtaph by L. Banacchi.) ' 



(pale purple to yellow) augite in a glassy base of felspar laths, 

 magnetite grains and purple augite. One specimen also shows large 

 phenocrysts of deep red l)asaltic hornblende together with pheno- 

 crysts of olivine and augite. 



These porphyritic basalts, to judge from a specimen collected by 

 Lieutenant Colbeck, were taken from a cliff in Robertson Bay, about 



