Art. VI. — Tlic Geology, of Castleniainc, zvitJi a sub- 

 division of part of the the Loiver Siluricxn Rocks 

 of Victoria, and a List of Minerals. 



By T. S. Hall, M.A., 



Demonstrator and Assistant-Lecturer in Biology, University 

 of Melbourne. 



(With Plate VI.) 



[Read lOtli May, 1S94.] 



The discovery of the graptolite succession in the Castlemaine 

 rocks has already !)een briefly indicated by myself in a short 

 paper contributed to the Adelaide meeting of the Australasian 

 Association towards the close of last year. In the present 

 communication I propose discussing the geology of the district in 

 more detail, and adding a few observations which have since 

 then come under my notice. 



In 1853 Sir Arthur Selwyn, then Director of the Geological 

 Survey of Victoria, examined the district, and made a traverse of 

 its northern part from the Campaspe to the Loddon, passing 

 through IVIounts Alexander and Tarrengower. He published a 

 sketch map, and a section along the line mentioned, and briefly 

 descriljed the physical features and the rocks of the district.* 

 Since then the most important work done has been the mapping, 

 by Mr. Geo. Ulrich, of a large extent of country from Harcourt 

 to Mount Franklin, and fiom Maldon to Elphinstone, on a scale 

 of two inches to the mile. Selwyn, in one of his reports,! gives 

 some interesting details of the work involved in the preparation 

 of these quarter-sheets. He says : " In the construction of the 

 Castlemaine sheet alone over 300 miles have been traversed 

 snlely to lay down topographical features, exclusive of the 

 contouring requisite for hills. Three thousand holes have been 



* Papers presented to Parliament 1853-4, vol. ii.— Reprinted in Q. J. G. S., vol. x., 1854. 

 t Geological Surveyor's Report, 1861. 



