330 AUSTKALASIAN ANTARCTIC EXPEDITION. 



DESCRIPTION OF PLATES. 



PLATE XLIV. 

 Fig. 1. Cordierite-Garnet-Plagioclase-Biotite-Gneiss, Stillwell Island (No. 980). 



The micro-photograph shows a mass of cordierite and biotite derived from 

 the alteration of an earlier garnet crystal. Mag. 80 diams. 



2. Hypersthene-Alkali-Felspar-Gneiss, Madigan Nunatak (No. 1227). The 



micro-photograph shows small biotite crystals proceeding from a 

 large ilmenite grain and projecting into felspar. Mag. 44 diams. 



3. Hypersthene-Alkali-Felspar-Gneiss, Madigan Nunatak (No. 778). The 



micro-photograph shows a synneutic aggregate of hypersthene in a 

 matrix of felspar. Reaction between the hypersthene and the 

 felspar has liberated ilmenite which has in places formed nuclei for 

 biotite growths which project into the felspar. Mag. 35 diams. 



4. The same rock as in Fig. 3. 



A portion of the field of the previous photograph has been considerably 

 enlarged to show more clearly the relation between the ilmenite, 

 biotite and felspar. Mag. 170 diams. 



PLATE XLV. 



Fig. 1. Amphibolite occurring in situ near the Magnetograph Hut at Cape 

 Denison (No. 421). 



Crystals of sphene with nuclear ilmenite are shown together with biotite, 

 felspar and a little hornblende. Mag. 35 diams. 



2. Garnet-Plagioclase-Amphibolite, in situ, Cape Denison (No. 977). The 



micro-photograph shows a reaction zone where dactylitic growths 

 of hornblende are the medium of transference of material from 

 ilmenite to garnet via felspar. Massive hornblende is also seen in 

 the field of view. Mag. 125 diams. 



3. Hornblende-Plagioclase-Pyroxene-Gneiss, in situ, Cape Denison (No. 



972). 



The micro-photograph shows a circular region where earlier garnet has 

 given place to a granulitic mass of pyroxene and felspar. Some 

 remnants of the original garnet crystal remain. Mag. 44 diams. 



Sydney : Thomas Henry Tenuant, Government Printer 1940. 



