32 Hall, Some Notes on the Gippsland Lakes. [vol"xxxi 



All these lakes and swamps are due to causes still in action, 

 and are among the most recent of the geological features of 

 our coast-line. The dunes that form their seaward margin 

 are still being added to along almost the whole of their course. 

 Behind the dunes the swamps and lagoons are gradually 

 filling, partly by sand blowing in from seaward, but chiefly by 

 the material washed down from the land. The old shore-line 

 behind the swamps can generally be readily traced, and 

 especially so when it was marked by cliffs. 



In the Gippsland Lakes, differing entirely in character from 

 the larger lakes, are three at the eastern end of the area — 

 namely, the North Arm at Cunninghame, Lake Bunga, and 

 Lake Tyers. These are narrow, winding sheets of water, and 

 are the drowned ends of river valleys which are deeply trenched 

 in the Tertiary plateau. They point to a subsidence of the 

 coast-line. The great depth of silt in the Mitchell River at 

 Bairnsdale, and at the crossing over the Nicholson, has given 

 much trouble to the engineers on the new Bairnsdale-Orbost 

 railway, and the long piles of the bridges have not found 

 bottom. This also points to recent subsidence. 



The Gippsland Lakes are bounded on their landward side 

 by a gravel-capped plateau of marine Tertiary rocks ; on the 

 eastern side of the lakes the plateau ends in cliffs, now partly 

 smoothed down by weathering, which are well marked from 

 Tambo Bluff to Red Bluff, near Lake Tyers. Westward from 

 Eagle Point, near the mouth of the ^litchell, the plateau slopes 

 down to sea-level more gradually, and without going over the 

 ground it is not always possible to mark the line on the map, 

 though the high land is always visible from the steamer. 

 Sale stands near the old shore, and from Paynesville to Sale 

 the former coast appears to run almost straight. There is, 

 however, some high land to the south of Lake King, from 

 Sperm Whale Head to slightly west of Red Bluff, which is 

 about a mile from the entrance of M'Lennan's Strait. This 

 Red Bluff must not be confused with the similarly named one 

 near the entrance to Lake Tyers. This high land I saw only 

 from the steamer, and am not sure of its character. At first 

 I felt sure it was part of the Tertiary plateau, but later, when 

 we were abreast of Red Bluff, it was clear that the cliif there 

 was dune. So I wrote " (?) Dune " along Sperm Whale Head 

 on my map. Since my return I mentioned the matter to Mr. 

 H. W. Wilson, who knows the lakes well, and he tells me that, 

 though he has not landed on Sperm Whale Head, he thinks 

 that red sands occur. This point needs looking into. 



On the east side of Lake Wellington Mount Cunningham is 

 marked on the map, but none of the ground rises much more 

 than twenty feet, if as much, so that this has probably the 

 distinction of being the lowest " mount " in Victoria. 



