Sequence of Rocks. 
89 
in the world's history. Each tells of races that lived, 
multiplied and died, of the lands that were tenanted, 
and waters thronged with life — so oft-repeated, again 
and again, that the mind, at first excited by the 
marvels, at last grows weary and loses itself in the 
contemplation of the works of the Infinite Creator/ 5 
dancing at the succession of strata as shown in 
Fig. 22, it will be seen that the oldest rocks on the 
Mountains are the Silurian slates and limestones. 
Next in order of age come the Devonian sandstones 
of Mount Lambie, and the Canoblas. The Permo- 
Carboniferous are seen to be newer than the 
Devonian, and newer still are the Hawkesbury Sand- 
stones, these last being of Triassic age. Much more 
recent than the sandstones is the basalt that caps 
Mount Hay, Mount Tomah, and Mount King George. 
This basalt was poured out subsequent, of course, to 
the formation of the sandstone, and before any of the 
Blue Mountain gorges were eroded. The basalt is 
therefore, geologically speaking, comparatively recent. 
So that between the formation of the sandstones and 
the out-pouring of the basalt there are many chapters 
of the geological record missing. In other words, no 
traces of Cretaceous, Eocene, Miocene, or Pliocene 
rocks remain on the Blue Mountains, if they ever 
existed. 
The succession of strata, as illustrated in Fig. 22, 
refers to New South Wales only. The geology of 
New South Wales cannot, however, be separated from 
