70 THE HAWKESBURY SANDSTONE. 
to which I have already referred. It is formed of very fine sani 
accumulated by the wind, and cemented by the re infiltration 
of water. In a short time the whole of this will be a hardened 
rock, and if the observations of Sir Wyville Thomson apa to 
be lost , it might easily be regarded as a marine rock, were it not 
that the deposit is full of the trunks of cedar trees which the wind 
wn down and mingled with the mass. I have very little 
doubt that much of the interior of Australia is composed of wind 
blown sand to a considerable depth. In 1863 I was able to 
examine a section of a well, sunk in a sandy heath-like country 
about 300 feet above the level of the sea. There was 90 feet ot 
laminated yellow, white, and red sands, resting upon foss 
miocene rock, e beds were in layers and laminations at like 
' the Hawkesbury rock, except that they were quite loose, and not 
aggregated together. This was on the edge of the Murray Desert, 
where there are tracts of sand-hills 100 feet and more in height, 
covered with a light growth of eae like vegetation, of which 
i A lanuginosum, Xanthorrea mines with various 
epacrids and sedges, form the Fria ook plants. Every three years 
or so these are burnt off, and then the sand blows about quite 
loosely. The are quite rounded, rassy level places are 
found in large tracts much below the level of the sand-hills, and 
then there is a stiff glay with swampy land, A sufficient accumu: 
The fine mud of the ee pana i in such gael which 1 a 
s, This Sicae repreediite the curious stratified 
saa found between the layers in the Blue ountains. a 
onstone. i gs must next 
ei our attention. As already obecrrey these fom a ms ee 
tic fea the Hawkesbury sandsto | them in 
rena hydrated peroxide of iron and the thick "bands ey ee 
most of the formation cannot fail to arrest the attention 5 pao i 
moreover, not only a feature in the Hawkesbury rocks, inte 
in these laminated sandstones wherever ig eal are et ie 
Range, Little Liverpool Range, ourees 
pool &e, of Fad here is ne a have 
from  pighociae) ores of i iron are terite, Fe 5 
- come drated peroxides as we t ‘ 
As to the daha a can be no doubt se cg ; 
ams 3et been entirely siliceous. It is often seen to be ¢ - Pnbleni 
ow, of fragments of mica, felspar, and fragnene 7 spe 
bade ‘other derived minerals, Hornblende dykes are 
ee ee of the older rocks from which t 
ay derived. In some hornblende se 
weaclibins oh tea ha te sisal oF a ksi 
