Recent Deposits. 
93 
happened in Cretaceous or in early Tertiary times. 
The reply is direct, and, I think, convincing. We 
believe the elevation to have taken place in 
Recent times because the fossils referred to, although 
now many miles from the sea, are all the remains of 
existing species, and in no way differ from what is 
now living in the adjacent seas. 
Nothing at all like this condition of things is 
known about Sydney. In the absence of any evidence 
pointing to elevation, there is a presumption that the 
land may be undergoing depression. But, so far, little 
or no direct evidence has been discovered in proof of 
any recent depression of our Coast. 
Attention has been drawn to a submerged forest 
at Shea’s Creek. In the absence of any more satis- 
factory explanation, this points to a relative change 
in the level of the sea or land. 
gEolian. — The sand-hills about Kensington, on 
Cronulla beach, and between Bondi and Port Jackson, 
are the best illustrations of wind-blown formations 
near Sydney. Altogether these wind-blown sand- 
hills cover a large extent of country from Port 
Hacking to Sydney. They can be observed in many 
places burying fences, trees, and even houses. The 
encroachment of moving sand-hills about Newcastle 
was at one time a source of considerable trouble and 
expense. 
Fulgurites, or tubes of fused silica, are not 
uncommon in these sand-hills. They are caused by 
lightning striking the sand, and in its passage fusing 
