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AUSTRALASIAN ANTARCTIC EXPEDITION. 



3. CHEMICAL CHARACTERS. 



The table below (Table V) contains the results of three chemical analyses. A 

 fourth analysis of the Broken Hill rock, the mineral composition of which is given in 

 Table I, is given for comparative purposes. 



TABLE V. 



I. No. 181, Porphyroblastic magnetite-garnet-gneiss, Adelie Land. Analyst, A. L. Coulson. 



II. No. 102, Garnet-quartz-magnetite rock, Adelie Land. Analyst, A. L. Coulson. 



III. No. 348, Garnet-magnetite-schist, Adelie Land. Analyst, A. L. Coulson. 



IV. Quartz-garnet-magnetite rock, Broken Hill, New South Wales.* Analyst, W. G. Stone. 



The analyses are noteworthy for their low silica as there is abundant free quartz 

 in each case. Felspar is an equally important constituent in Nos. 181 and 348 where 

 appreciable alkalies are present. Felspar is not recorded in No. 102 or in the Broken 

 Hill specimen and the total alkalies are extremely small. The remarkable high 

 content of magnetite and garnet is reflected in the high total iron. Lime and magnesia 

 are extremely low and reflect the paucity of ferromagnesian minerals. Magnesia is 



" Geology of the Broken Hill District," E. C. Andrews. Mem. 8, Geol. Surv., N.S.W., p. 172. 



