Palaeozoic Geology of Victoria. 121 



The above description also concisely describes the features of No, 

 ^d>. The occurrence of this rock is! shown in Map 4, near the head 

 of one of the branches of Ironstone Creek. The outcrop, however, 

 is very limited, being partly surrounded by late Kainozoic sands and 

 gravel f5. 



The relationship to the igneous rocks of the district is not shown,, 

 but it is almost certainly later than the earliest members of the 

 Snowy Kiver Series, which show here various stages of shearing 

 with the development of porphyroids. Some of these outcrop in the 

 stream bed a short distance below the ceratophyre. 



From the chemical analysis of No. 68, applying the American 

 Classification, it is interesting to note that it falls into the persodic 

 Subrang, noyangose, of liparase, the per-alkalic Rang. (I) of 

 britannare, the quardofelic Order (4) of persalane. Class 1. 



Analysis and Molecular Ratios and Classification. 



SiO, 



72.41 ■ 



- 1.207 



A1.,0, - 



14.38 ■ 



- 0.141 



Fe.p3 - 



2.94 ■ 



. 0.018 



FeO 



0.85 ■ 



• 0.012 



MgO - 



1.18 



- 0.029 



CaO 



0.87 - 



0.015 



Na.,0 



6.86 - 



0.110 



KoO 



0.13 



- 



H.,0 -t- - 



0.67 



- 



H..0 - - 



0.04 





CO., 







TiO., 



0.26 



- 0.003 



P.O, - 



0.17 



- 0.001 



MnO 



0.09 ■ 



. 0.001 



Total 



100.85 





Quartz 



29.28 



Orthoclase - 



0.55 



Albite 



58.16 



Anorthite - 



3.33 



Corundum - 



2.84 



Hyperstlieue 



2.90 



Magnetite - 



2.32 



Ilmeiiite 



0.45 



Hematite - 



1.28 



Class - 



1 



Order 



4 



Rang - 



1 



Sub rang 



5 



Maginatic Name, Noyangose. 



S.G. 2.63 



Granife liocl-^. — Only one small occurrence of granite has l)eon 

 noted in the area included in the map. It is limited to an exposure 

 of a few chains extent along the bed of one of the branches of the 

 Tara Creek, No. 9.S. On the west it is in contact with the frag- 

 mental igneous rocks of the Snowy River Series. No evidence of 

 contact alteration of these rocks was noted, nor have any dykes 

 or offshoots of granitic rocks into them been observed. It is prob- 

 able, therefore, that the granite is the older rock. A much more 

 extensive outcrop of granite closely similar macroscopically, and in 

 thin sections also, occurs a few miles to the east of the Tambo River, 



