370 Proceed I }i(j^ of fJie lioi/al Sucietjj of Victoria. 



preserving a remnant of once more extensive beds on account 

 of their having been locally depressed. 



This adds another to the numerous instances now known 

 showing that local disturbances of deposits about the age of 

 our deep leads occvir, and that consequently it is not safe to 

 assume that in working the deep leads they wiU maintain with- 

 out variation their original slopes. As early as 1875 Mr. R. A. 

 F. Murray called attention to the difl&culty in explaining the 

 direction of fall in some of the Ballarat leads/ and noted an 

 instance at Buninyong of a lead dipping both ways.^ I have 

 since shown that local subsidences can explain the disturbance 

 at this locality, though I suggested a possible explanation also 

 by a succession of volcanic vents. ^ 



In 1882 a fault was met with traversing the gutter at the 

 Hepburn Home Paddock Gold Mine. It produced an abrupt 

 change of level in the lead of 23 feet, followed by a greater dip 

 than usual for the next 500 feet of the lead down stream. It 

 is shown in a section prepared by the manager (Mr. J. T. 

 McKenna), and now in the possession of the Ballarat School 

 of Mines. Local subsidences have also recently been given by 

 Professor Gregory as the explanation of an area occupied by 

 tuffs in the workings of the Spring Hill and Central Mine,^ and 

 for various lakes in the Western District of Victoria. 



In conclusion, I desire to thank Mr. H. Herman for a tracing 

 of an unpublished map of the basin made by Mr. S. Hunter. 



References. 



I. — Geology and Mineial Resources of Ballarat. R. A. F. 

 Murray : Progress Report Geological Survey of Vic- 

 toria, No. I., pp. 76, 77. 



2.— Ibid, Figure 16. 



3. — Proc. Roy. Soc. Vic, vol. xii., part 1. 



4. — Bulletins of the Geological Survey of Victoria, No 1. 



DESCRIPTION OF PLATES. 



No. XXV. — Plan showing the position of Stony Creek Basin, 

 and its relation to the Corinella Dyke. 

 XXVI. — Plan of the Basin on a larger scale. 



