332 N. li. Jminev 



(b) Dip (tnd strike of the siluria/i and evidence of pitch. 



The strike of the folded sediments is fairly constant tliroughout. 

 The maximum value of the strike is about north 45 deg. east, and 

 the minimum value is a few degrees west of north. The average 

 value is about north 20 deg. east. It is only in the Avest and 

 northern parts of the area that any considerable variation from 

 the average value occurs. To the north-west of Greensborough, 

 near the bend to the west of the Plenty River, the strike is nearly 

 north and south. The dip varies considerably, and when away 

 from the axial lines the average value is between 50 deg. and 60 deg. 

 In the east and north-east of the area, Jutson^ has shown that the 

 beds have a decided northerly pitch. Certain sections along the 

 aqueduct illustrate this very well. Near Diamond Creek and 

 further west near Greensborough, however, no defined regional pitch 

 occurs. Mr. Dunn- has stated that the pitch of the beds near 

 Diamond Creek is to the north. The writer has not been able ta 

 verify this, and he believes that no regional pitch is here present^ 

 but that minor local pitches do not infrequently occur. 



(c) Relation of mining helts to structural features. 



Since the fine and instructive paper by Emmons^ in 1886, it has 

 become more and more recognised that the study of the structural 

 features in any mining field is essential to the complete mastering 

 of the various problems connected with the ore deposits. We have in 

 Victoria, at Bendigo, perhaps as fine an example of this connec- 

 tion as we might wish for. It is essential, therefore, that wc .should 

 study the structural features in some detail. This has been done- 

 to some extont above, and it has been seen that the payable quartz 

 reefs in the silurian in this urea, in practically all cases. 

 are localised to near the axial lines, and generally to 

 near the anticlines, and a reason for this has been sug- 

 gested. Synclinal reefs do sometimes occur, however, as 

 at Warrandyte,^ and in a section along the railway line 

 between Greensborough and Eltham, a minor anticline and syncline 

 occur with a thin bedded svnclinal reef. Jointing lias been shown 



1 Jutson. c, p. 525. 



2 Op. cit. 



3 S. F. Eninioiis. The structural features of ore deposits. Trans. Aiiur. Inst. Min. Kng., 

 vol. xvi., p. 804-839. 



4 Jutson, c, p. 535. 



