Palaeozoic Geology of Victoria. 69 



3. Serpentinous Grit, Upper Cambrian, Dolodrook River. 



4. Rhyolite Tuff, Upper Palaeozoic, Lake Kariig, Mt. Wellington. 



5. Melaphyre, Upper Palaeozoic, Wallaby Creek, Wellinjjtan Divstrict. 



6. Porphyroid, Lower Devonian, Ironstone Creek, Nowa Nowa. 



7. Porphyroid, Lower Devonian, Bog-gy Creek, Nowa Nowa. 



8. Altered AiUdesite. Lower Devonian, Boggy Creek, Nowa Nowa. 



9. Trachytic Andeeite, Lower De^'onian, Nowa Nowa. 



10. Quartz-Porphyrite, Lower Devonian, Tara Range. 



11. Quartz-Ceratophyre, Lower Devonian, Nowa Nowa. 



12. Quartz-Ceratophyrej Lower Devon.ian, Nowa Nowa. 



Descpiption of Photomicrographs. 



•Fig. 1. — ^Ser'ientinized peridotite, E-Jiowing some unaltered olivine. Prc- 

 Upper-Cambrian, Serpentine area, Mt. Wellington District. 



Slide No. 182. Ordinary light x 40. 



.Fig. 2. — Serpentinous g^^it, showing much calcite and altered basic 

 igneous fragments. Upper Cambrian. Dolodrook R., Loc. B. 



Slide No. 39. Ordinary light x 40. 



Fig. 3. — ^Serpentinous grit, showi::g much calcite, one example twinned, 

 also felspar and pyroxene fragments much altered. Upper Cam- 

 brian, Loc. B. 



No. 41, Crossed Nicols x 40. 



Fig. 4. — Rhyolite tuff, showing irregular tube structures set in felsitic 

 ground-maes. Upper Palaeozoic, Lake Karng, Mt. Wellington. 



No. 111. Crossed Nicols x 40. 



Fig. 5.— Melaphyre, s^howing abundant laths of triclinic felspar, rrobably 

 oliigoclase, with some chlorite and magnetite. Upper Palacozv:ric, 

 Wallaby Creek, Mt. Wellington District. 



No. l';7. Ordinary light x 40. 



Fig. 6. — Porphyroid. Schistose structure indicated by lines of sericite ; 

 some tricline felspar fragments are f-'^t in a schistose felsitic 

 base. Lower Devonian. Ironstone Creek, Nowa-Nowa, 



No. 27. Crossed Nicols x 40. 



Fig. 7. — Porphyroid. Schistose structure indicated by lines of sericite; 

 felspar fragments small a.nd less abundant. Lower Devonian, 

 Boggy Creek. 



No. 2. Crotjsed Nicols x 40. 



F^. 8. — Altered Ar.desitr. Phenocrysts of triclinic felr.par of ?tout 

 habit and chloritized ferro-magnesian minerals in a microcrys- 

 talline ground-mas-:. Lower Devonian, Bcjgy Creek. 



No. 11, Ordinarv light x 40. 



Fig. 9.- — Trachytic-Andesite, showing abundant triclinic felspars of 2 

 generations and central felspar, showing secondary alteration. 

 Lower Devonian, Boggy Creek. 



No. 12. Ordinarv light x 40. 



Fig. 10. — Quarlz-porphyrite, showing eimbayed quartz phenocryet. Lower 

 Devonian. Tara Range. 



No. 105. Crossed Nicols x 40. 



.Fig. 11.— Quartz-oeratophyre, showing triclinic feKriar phcnocrystH, prob- 

 ably andesine. Lower Devonian, Nowa-Nowa. 



No. 68. Crossed Nicols x 4<>, 

 Fig. 12. — Quartz ceratophyre (featuree afi in Fig. 11). 



No. G8. Cro**sod Nicolfl x 40. 



2a 



