Geology of the Lower Mitchell River. 15 



at Hillside, inverted conical depressions of considerable area 

 occur, as much as from 200 to 300 feet in diameter and from 50 

 to 60 feet in depth, such as are common in other limestone 

 districts. 



The flats on the banks of the Mitchell vary in width from 

 about two miles at the upper end to less than half a mile at 

 Bairnsdale, where they are confined by limestone cliffs. Their 

 fall follows that of the river, and is approximately 100 feet in 

 about 25 miles. The soil on them consists for the most part of a 

 loose, friable, siliceous material of great depth. In the upper 

 portions of the river, where its fall is greater and the flats are 

 wider, the genei'al slope is from the higher, more distant 

 banks towards the stream ; in places where subsidiary channels 

 have formed, the slope is towards them ; in flood times it 

 is by the backing up of water in these that portions of the 

 flats are submerged. In the lower portions of the river, the 

 banks now enclosing the channel are much higher than the 

 flats which, in general, fall away from them, and towards the 

 earlier formed, more elevated banks that bound them, so that 

 during floods the actual margins of the river are the last portions 

 to become submerged. The bed of the channel itself was 

 originally confined between banks which were covered with dense 

 vegetation. Above Lindenow the stream at one time consisted 

 of long stretches of deep water and shallow rapids over loose 

 stones. Below Hillside there was one continuous deep channel 

 to the mouth of the river. The present state of the stream is 

 widely different. The river banks have been denuded of 

 vegetation, and broken down in many places by stock, with the 

 result that the loose, friable soil has disappeared by the acre, and a 

 stony gravel bed, sometimes over a hundred yards across, has 

 been exposed ; the banks also have been left vertical, to wash 

 farther and farther away with every flood. The lighter material 

 is swept over the lower lands and passes into the lakes, while the 

 heavier material is continually creeping down what was once the 

 deep channel of the river, plugging it up solidily as it goes. 

 This action has gone on until it is now possible to ford the river 

 near Bairnsdale, wliile in the earlier days the Manaro crossing at 

 the Wuk Wuk village settlement, was the point at which the 

 river was fordable. Below Bairnsdale the river is from 200 to 



