Country ISooJli. of Yarra. 2^3 



Wlieeler'.s Hill, that is, tu the last oi" tlic hill; hut also that the 

 liill seeiiis to rise above the general height of the plateau in this 

 locality. Possibly there may be a fault on the north-east of this 

 grou]) of hills, but the detleition jn-oduced in the Dandenong Creek 

 may l)e sutlicient cause for the steep slope along the north-east 

 fall. My suggestion that there has once been a continuous ridge 

 lo beyond Surrey Hills niiiy raise the objection that it would seen 

 that the count iv about Blackburn sliould have had its easiest outlet 

 to Koonuug ('reck, which, with a <lirect course, now joins the 

 Varra ai 2-1 ft. above sea levtl. But if we imagine the low vallov 

 of Koonung ('reck tilled in. and the ridge from East Cand;erwt,ll 

 continuous to Doncaster, the outlet of this area is difficult by any 

 route, and Main Creek might at some stages in the <levelopment 

 be the easier in spite of the necessity to cut through the ridge. 



Jutson (p. 470) mentions a decreasing throw of the Brushy Creek 

 fault from north to south till it is no longer traceable as a fault, 

 and appears to be represented by a gentle tilting on a line con- 

 tinuing south-westerly toward Springvale (with a possible fault for 

 a sh(n-t distance at Wheeler's Hill). Following this idea it 6eeo>H 

 better to consider this fault line as replaced by a wider easterly 

 tilt from the Notting Hill axis. Then the course of the Dandenong 

 Creek at Wheelci's Hill is in accordance with the direction of tilt 

 till it finds its way tlirough the hills. The Springvale valley also 

 lies within tlie tilted area and further south the tilt extends from 

 Beaumaris across the ('armim Swamp. 



The slope on which the formation of .swampy land appeals at 

 the lower parts of the creeks is in close agreement in the three 

 examples in this district. The Dandenong Creek begins to l)e 

 s\va,m]»y below the 50 ft. contour, falling from 50 to 40 in 50 

 <liains, or a grade of 1 in .'5.'{0. The channel from Dingley south- 

 Avard falls from oO to 30 in 65 cliains, and from 30 to 10 in about 

 105 chains; this biings it into the once swampy land north of tlie 

 main drain from the Dandenong Creek to Mordialloc. The Elstern- 

 wick ("reek falls fiom 50 to .')(• in (50 chains, and from 30 to 10 

 in 100 chains; thence to the outlet is much flatter. 



In I'onsidering the lagoons, the question suggested itself as to 

 whether there was any cause acting to keep them from silting up 

 <ir even to increase their size. In spite of statements about running 

 sands in some wells, there does not seem much likelihood of under- 

 grouTnl channels l)y wliich sand could move; and actually the 

 closed hollows usually liold water. There seems a slight possi- 

 bility that under pecviliar circumstances some of the upper sand 

 might slip in mass on an inclined clayey bed either doMn a valley 



13a 



