Fetrolo;/;/ and (leoUxjii of (Jveci.^toU'H J)isfricf. 123' 



the writer at tlir Iniprrial ('(.lU-s;e of Seieme. London. For (uii-- 

 poses of comparison. t\v(. vury similar analyses of ofher Victorian 

 diorites are appended. 



II. III. 



49.65 52.03 



16.7a 23.57 



0.31 1.60 



8.99 6.90' 



5.88 5.39 



7.87 7.80 



0.80 1.34 



3.10 2.31 



2.50 1.2? 



0.14 0.26. 

 1.08 

 0.04 

 0.14 



2.81 n.dt 

 n.det>. 

 NiO tr. 



100.04. 99.60. 

 2.91 2.855 



A me ricaii Classifiaitivn. 



Maguiatic Name Bandose tfes.sose Hessose 



near Hessose 



I. Quartz Diorite, Caledonia Mine, Queenstown. Analyst, N. R„ 

 Junner. 



II. Quartz Diorite, Morning Star Dyke, Wood's Rnnt. Analyst,. 

 N. R. Junner. 



III. Quartz Diorite, Dargo. A. W. Howitt.^ 



The chemical analysis of the Queenstown rock confirms its micro- 

 scopical determination as a quartz diorite. The marked excess of 

 soda over potash, and the relatively high percentage of lime, finds 

 expression in the predominance of soda lime felspais over jjotasb 

 felspars. The high percentages of water and cail)on dioxide are 

 due to the presence of chlorite and calcite. and do not signify that 

 the rock has suffered weathering, as these minei-als are regarded as- 

 being formed immediately after the consolidation of the rock_ 



1 Vidr, Proc. Roy. Soc. Viotoii.a, 1SS7. 



