CA Proccedi)igs of tJie^ Royal Society of Victoria. 



of the South Wattle Gully Co.; while the once fabulously rich 

 mines on the other side of Wattle Crully, are as near to a syncline 

 as to an anticline. The Bolivia reef occupies a fault with a. 

 western hade, the country rock dipping east. The country in 

 the neighbourhood of quartz reefs is usually so disturbed that 

 observations of dip are unreliable in these localities. 



Rock fo/diui:^. — The whole series of rocks is much folded and 

 crumpled. Hand specimens may be gathered which show the 

 folding on the most minute scale and such crumpled rock gener- 

 ally occurs near the axis of one of the larger anti- or synclines. 

 To this puckering, I feel constrained to put down most, if not ;<11 

 the instances quoted, of " ripple marks " in our silurian rocks. 

 Two such instances may be noted. Mr. E. J. Dunn*' speaking 

 of the Bendigo " saddle-reefs," describes the rock slipping that 

 must have taken place during their formation,! and then notices 

 that one wall of the original cavity shows ripple-marks beauti- 

 fully develo23ed, that is, just at the place where rock-slipping 

 must have been greatest. The other instance occurs in the bed 

 of the Moonee Ponds Creek, near the Park Street bridge. In 

 this case also, there has been considerable rock movement, for 

 the bed which shows the marks is about eighteen inches below a 

 thrust-plane, which is accompanied by shattered rock, and small 

 veins of quai'tz. Innumerable other instarices may be quoted, 

 but when we are dealing with rocks like those of Castlemaine, 

 which have an average dip of over 70°, or of Bendigo with one of 

 65°, the simplest explanation seems to be that the structure is a 

 form of crumpling, for were it otherwise, its observance would 

 be a rarity instead of one of the commonest of occurrences. 



The larger anticlines succeeded each other very rapidly, the 

 average distance being 300 yards. In the water-race from 

 Chewton to Castlemaine, along the hill slopes to the seuth, I have 

 plotted thirteen in two and a half miles. This agrees closely 

 with what occurs at Bendigo. 1 The anticlines can be traced for 

 long distances. For instance, I have traced the anticline through 

 Monument Hill for two and a half miles. The anticlines have 

 a fairly constant strike of N.5°W. Owing to the way in which 



" Loc. cit., pp. 6 autl 12. 



t See also Wm. Nicholas, F.G-.S., in Bendvjo Adverliscr, aul Bendijo ludej^endenl, August 

 27, 1881, for similar explauatiou. 

 J Dunn, loc. dr., plan. 



