Palaeozoic Geology of Victoria. 12^ 



igneous rocks, plutoiiic and volcanic, conform closely to the graphs-, 

 with the Dacites at the least acid end, and the granites of Gabo, 

 Woolamai, etc., at the other end. 



The quartz porphyrites of the Tara Range are found to occupy a 

 position corresponding very closely v^'ith that of the Gabo Island 

 granite, and as has been shown petrographicaily, it is with a granite- 

 of this type that they appear to be associated. 



It Avould appear, therefore, that the acid rocks of the Snowy River 

 Series belong to an acid alkali province, in contrast to the acid 

 sub-alkali province, to which the dacites and grano-diorites belong, 

 but all conforming to a normal variation curve. 



It -^^'ould be further interesting to consider the position and rela- 

 tionship of' the andesites, but these rocks are much altered and de- 

 composed, and, so far, no specimens suitable for analysis have been 

 obtJained. 



It is worthy of note also that porphyries and rhyolites of the 

 Wellington Series form again a more acid series than those of the- 

 Snowy River. 





1 



H 



3 



4 



5 



6 



7 



SIO. 



- 72.55 - 



73.41 - 



71.68 - 



70.51 - 



72.41 - 



72.39 - 



72.49- 



Al.,6., 



- 11.74 - 



12.30 - 



13.57 - 



14.36 - 



14.38 - 



14.42 - 



13 48 



Y^\0, 



- 2.54 - 



2.09 - 



1.28 - 



0.33 - 



2.94 - 



0.56 - 



1.16 



FeO 



- 0.46 - 



2.13 - 



1.94 - 



1.95 - 



0.85 - 



0.30 - 



2.09- 



MgO 



- 0.68 - 



0.14 - 



1.37 - 



1.08 - 



1.18 - 



1.85 - 



0.49- 



CaO 



- 1.85 - 



1.08 - 



1.88 - 



2.98 - 



0.87 - 



0.85 - 



1.31 



Na^O 



- 3.46 - 



3.71 - 



2.22 - 



3.17 - 



6.86 - 



5.93 - 



338 



K,0 



- 4.41 - 



4.04 - 



3.87 - 



3.15 - 



0.13 - 



1.23 - 



4.06 



H,0 + 



- 0.41 - 



1.51 - 



1.24 - 



1.18 - 



0.67 - 



1.13 - 



0.76- 



H^O- 



- 0.06 - 



0,10 - 



0.29 - 



^^ 



0.04 - 



— ■ - 



0.18 



co, 



- 1.80 - 



^ 



0.08 - 



nil - 



nil - 



— - 



tr. 



TiO, 



- 0.175- 



0.16 - 



0.33 - 



1.20 - 



0.26 - 



— 



0.46- 



PA 



- 0.14 - 



tr. 



0.03 - 



0.12 - 



0.17 - 



tr. 



— 



NiO 















0.08 - 



— 



— 



— 



MnO 



— - 



— - 



0.13 - 



— - 



0.09 - 



O.Ol - 



0.13- 



100.27 100.67 100.11 100.85 98.67 99.99- 



1. Quartz Porphyrite, No. 100, Mt. Tara Range. 



— Anial.yst E. O. Teale. 

 2.. Quartz Porphyribe, No. 105, Mt. Tara Rauge. 



—Analyst E. O. Teale. 



3. Quartz Porphyry, Federal Territory. 



—Analyst A. G. Hall. 



4. Quartz Porphyrite, Violet Town, Strathbogie Range. 



— ^ Analyst G. Ampt. 



5. Quartz Ceratophyre, No. 68, Nowa Nowa. 



—Analyst E. O. Teale. 



6. Quartz Ceratophyre, Navlgtatiou Creek, Noyang. 



— Analyst A. W. Howitt. 



7. Granite, Gabo Island. 



— Analyst J. Watson 



