86 



AUSTRALASIAN ANTARCTIC EXPEDITION. 



Other sections show variation in the degree of metamorphism of the rock. The 

 crush areas may be less abundant and the andesine felspar better preserved. The 

 twin lamellae of the andesine may be curved and bent by the pressure. At the same 

 time there may be less sericite, less perthite, and less of the diablastic structure. In 

 other cases muscovite may be better developed, or chlorite may replace a portion 

 of the biotite, while green hornblende may appear. 



The microscopical examination, therefore, renders it apparent that this gneiss 

 is the metamorphosed equivalent of a granite or a granodiorite. 



CHEMICAL CHARACTERS. 



The following analysis .of the type specimen No. 11 was made in Victorian 

 Geological Survey Laboratory : 



Magmatic Name .......... Amiatose Amiatose 



I. Granodiorite gneiss, Specimen No. 11, hut site, Cape Denison, Adelie Land. Analyst, J. C. Watson- 

 II. Granodiorite, near Old Sawmill, Hesket, Macedon District No. 35. Analyst, A. Hall* 



III. Typical banded gneiss, north side of Hopkin's Bay, Rainy Lake, Canada, t 



IV. Biotite gneiss, near Sangobeag, Durcess, Scotland J 



" Annual Report of the Secretary of Mines, Victoria, for 1907," p. 61. 



The Archaan Geology of Rainy Lake, Restudied," A. C. Lawon/Geol. Surv. Canada, Mem. 40, p. 93. 

 The Geological Structure of the North-West Highlands of Scotland," Mem. Geol. Surv. Gt. Britain, 1907. 



