ANTARCTIC ROCKS AND MINERALS. 39 



Basaltic Andesite. 

 Olivine Dolerite. 

 Olivine Basalts. 

 Limburgites. 

 Basic TufF. 



Mica Schist (Biotite). 

 ^b) Specimens from Possession Island — 

 Amygdaloidal Trachyte. 

 Augite Andesite. 

 Basalts. 



The specimens presented to the Tasmanian Museum 

 have been placed at the autlior's disposal, through the 

 kindness of Mr. A. Morton, and comprise the following — 



Minerals — 



Quartz, containmg Siderite. 



Ferruginous Quartz Specimen. 



Massive Olivine. 

 Rocks — 



Basalt (Olivine). 



Basalt (Olivine). 



Basalt (Hornblende). 



Scoriaceous Basalt. 



Sandstone. 



Mica Schist. 



Decomposed Basalt (?) Ferruginous. 



Taking these in the order above given, the first speci- 

 men is that of a milk-white variety of quartz, attached 

 on one side to mica-schist, and fringed on the other edge 

 (water-worn) with crystalline carbonate of iron. 

 Another more massive specimen is a ferruginous or 

 " rusty " quartz. Unfortunately, these specimens are 

 barely large enough to permit of assay specimens being 

 taken ; still, the appearance of quartz w^ould warrant 

 prospecting for gold, if climatic conditions were 

 favourable. 



The remaining mineral specimen consists of a granular 

 and fragile massive mineral, pale green in colour, and 

 resembling bottle glass. The hardness, colour, and 

 chemical tests (yielding Si O^, Mg O, and a little Fe O) 

 clearly point to the mineral ])eing " olivine." This is a 

 particularly fine specimen, and the mineral probably 

 occurs in connection with the basalts to be mentioned. 



