6Q 



J. A. Dunn : 



scratched for gold in the past, although in rather a spasmodic 

 manner. • 



The sediments are represented by sandstones and slates of 

 varying composition and texture, there being every gradation 

 between the normal sandstone and normal slate. In Bendigo 

 these have been mineralised to some considerable extent by the 

 impregnation of quite a high percentage of pyrite, with lesser 

 amounts of arsenopyrite, galena and sphalerite. At Big Hill 

 these sulphides are practically absent, but the Ordovician has 

 been metamorphosed fairly extensively with the formation of 

 micaceous sandstone (in some places the mica is in quite 

 coarse plates), whilst the occurrence of chiastolite in the slates 

 is common throughout the metamorphic aureole. 



Inclusion of Country Rock (A), surrounded by Basic 

 Segregation (B), in Granite (C). 



3. — The Harcourt Granite Intrusion. 



The granitic mass of Harcourt has never been critically exam- 

 ined, but it has generally been looked upon as a granodiorite 

 similar to that of Macedon, Dandenong,* Mount Eliza and Mount 

 Martha. The high percentage of SiO^ and the possibility that 



