152 Proceedings of the Royal Society of Victoria. 



10. Ranft, J. A. H. T. — Origin and Formation of Auriferous 



Rocks and Gold. Sydney, 1889. 



11. Selwyn, A. R. C — Notes on the Pliysical Geography, 



Geology, and Mineralogy of Victoria. Intercol. 

 Exhib. Essays, 1866-67. Off. Rec, pp. 147-227. 



12. Selwyn, A. R. C. — A Descriptive Catalogue of the Rock 



Specimens and Minerals in the National Museum. 

 96 pp. Melbourne, 1868. 



13. Walker, B. D.— Report on Neglected Gold Fields, Part 



II., Spec. Rep. Dep. Mines Vict., 1894, 12 pp. 



14. Whitelaw, O. A. L. — Geological Sketch Map of the 



Parish of Heathcote. Mines Dep., Sept., 1896. 



III. — The Geological Sequence at Heathcote. 



The palaeozoic rocks at Heathcote may be divided between 

 four systems. The famous glacial deposits of Derrinal occur to 

 the west ; though often recorded as mesozoic, they are probably 

 of upper carboniferous age. Their only concern with this paper 

 is that they are rich in fragments of the metamorphic and 

 diabase rocks. The remaining palaeozoic rocks belong to the 

 Silurian and ordovician systems, and to a group of igneous 

 and metamorphic rocks. 



III. (A). — Silurian. 



The Silurian rocks lie to the north-east of Heathcote, and 

 occur as a thick series of breccias, conglomerates, quartzites and 

 quartzose grits. Certain bands are extremely rich in fossil casts, 

 including encrinite stems, brachiopods, gastropods, and occa- 

 sional trilobites. I have not given attention to the palaeon- 

 tology of these beds ; but they contain a Homolonotus of the 

 type found in the lower part of the Victorian silurian system. 

 Further east the sandy type is less persistent and some shales 

 occur. The prevalent strike of the silurian rocks is from north 

 to south, but around Mount Ida the strike is from east to west ; 

 this cliange is no doubt due to a fault, which is now hidden by 

 the valley to the south of the mountain. In the breccias the 

 pebbles are mainly quartzites, derived in the main from the 

 silurian and ordovician rocks. Mr. Lidgey has recorded the 



