There have been some recent additions to the geological data that's available on the Vic Govt website. The search engine works well. Lots of historical maps have been scanned.
http://geology.data.vic.gov.au/searchAssistant
As an example, I searched for Dunolly and this is a map that is available:
http://geology.data.vic.gov.au/reports/maps/31680/G10933_58p_31_parishplan.jpg
http://geology.data.vic.gov.au/searchAssistant
As an example, I searched for Dunolly and this is a map that is available:
http://geology.data.vic.gov.au/reports/maps/31680/G10933_58p_31_parishplan.jpg