Report cm the Rock-Specimens . 



327 



The red glassy scoriaceous hornljlende-basalt at Cape Adare 

 was seen by Mr. Bernacchi to be traversed by small dykes 

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

 basalt 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. 

 (From a Photograph by L. Bernacchi.) 



(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 



