of the Buchan District. 105 



As to the period at which these faults were formed, I 

 cannot well form an opinion beyond this : that they are 

 subsequent in age to the Middle Devonian, for they pass 

 through the Buchan beds, which, in the locality referred to, 

 terminate the geological record .* 



* In the Report of Progress, No. 5, of the Geological Survey of Victoria, 

 p. 134, I' suggested an explanation of the formation of the ore deposits at 

 Murendel. At that time I inclined to the belief that the black basalt-like 

 rocks at Back Creek might be intrusive. Subsequent investigations have shown 

 that these rocks belong to the Diabase porphyrites, and are contemporane- 

 ously interbedded in the Buchan series. It is therefore necessary to point 

 out that in so far my suggestion requires to be modified, but it may remain 

 as to the probable reactions between metaUic solutions permeating the faults 

 and the organic constituents of the limestones which they traversed. 



