583 



in composition with a quartz-ceratophyre from the Noyang 

 district of Gippsland. The Victorian rock was formerly 

 described, by the late Dr. A. W. Howitt, as a quartz- 

 porphyrite, but later referred to by Professor Skeats as a 

 quartz-ceratophyre. ( 2 ) 



Analyses of some of the Gippsland ceratophyres are given 

 for comparison. 



3. Aplites. 



It would be interesting to have the analysis of the aplite 

 also, for it appears probable that the latter may be genetically 

 related to the ceratophyre; but T have so far been unable to 

 find time for this work. 



The prevailing felspar in the aplite is a microcline, and 

 the question is raised as to whether it is the normal potash 

 type or the soda variety, anorthoclase. 



Si0 2 ... 



A1 2 3 ... 



Fo o 3 ... 

 Feb 



MgO ... 

 CaO 



Na„0 ... 



K„6 ... 



H,0- ... 



h;o+ ... 



P o 5 ... 



MnO ... 



Ti0 2 ... 



Total ... 



Sp. Grav. 



A 



B 



C 



D 



76-26 



77-66' 



78-77 



72-41 



12*40 



12'30 



12'44 



14*38 



1'64 



0'61 



0-95 



2-94 



2'60 



0'17 



— 



0-85 



trace 



0-73 



0-02 



1-18 



0*28 



0*16 



0*53 



0'87 



6'27 



6-96 



6'79 



6*86 



•41 



0'19 



0-24 



0*13 



■12\ 



•02/ 



0*46 



0*26 



r o-04 



1 0-67 



trace 



trace 



— 



0*17 



— 



— 



— 



0*09 



0-50 



— 



— 



0-26 



100-50 



99*24 



100-00 



2'59 



100-85 



2-63 



A — Spec. No. 13. Quartz-Ceratophyre, Cathedral-rock Greek, 

 Mount Remarkable. Anal., E. O. Thiele. 



B — Quartz-Mica-Porphyrite (Quartz-Ceratophyre), Naviga- 

 tion Creek, Gippsland. A. W. Howitt. 



C — Quartz-Porphyrite (Quartz-Ceratophyre), Mount Eliza- 

 beth Creek, Gippsland. A. W. Howitt. 



D — Quartz-Ceratophyre, Nowa Nowa district, Gippsland. 

 E. O. Thiele. 



(2) "The Volcanic Rocks of Victoria," Prof. 

 D.Sc, A.A.A.S., Brisbane, 1909. 



E. W. Skeats, 



