298 H. S. Summers: 



Dog Creek Falls, having a fairly coarse granular groundmass. 

 From this we pass to a granite porphyry, which in itself shows 

 an increase of coarseness of grain as we descend the hill, and 

 finally to the coarse-grained plutonic granite occurring along the 

 river nearly 2400ft. below the summit of the hill. 



In deA^onian time the highlands were oontinuous from the 

 Strathbogies across the present valley of the Broken River to the 

 ToombuUup Ranges, and this ridge formed the northern boun- 

 dary of the basin in which the carboniferous sandstones were laid 

 down. 



So far I have only examined the carboniferous sandstones 

 sufficiently to show that they are ycunger than the granites and 

 porphyries which underlie theiu. The age of the oonglnmerate 

 is extremely doubtful. Tliey are certainly post-carboniferous as 

 fragments of carboniferous sandstones are present in them. If 

 of alluvial origin they are }>robably of pliocene age, but if of 

 glacial origin they may go back as far as iDermo-carboniferous. 

 To the north Mr. A. E. Kitson records several patches of con- 

 glomerates of glacial origin at Greta, Ta-minick and Glenrowan, 

 and suggests that they are possibly permo-carboniferous in age, 

 from their general similarity to the conglomerates of Bacchus 

 Marsh. 



SriTABITJTY OF ArEA FOR WaTER CONSERVATION. 



In considering the soiitability of the area for water conserva- 

 tion purposes it is necessary to discuss the geological features 

 of the area of the reseiToir. the catchment area., and more briefly 

 the area to be served. , 



The reservoir area is bounded on the east and west mainly 

 by granitic rocks with some silurian sediments on the eastern 

 side. The south and south westward biumdaries are composed 

 of carboniferous sandstones. High level alluvium may border 

 portion of the area-, but if this were stripped off it would be 

 seen that the proposed reservoir was surrounded on all sides 

 except a narrow outlet to the north by rocks of palaeozoic age. 

 This then should give a basin from which very little soakage 

 could take place, the only parts where slight loss might be ex- 

 pected being along the junctions of the different series and down 

 any fault and joint planes present in the rocks. 



