10 
Contents. 
CHAPTER IV. 
RUCKS. 
What is a Rock ? — Materials of Rocks — How to Study Rocks 
— Classification of Rocks — Rocks of Sydney and the Blue 
Mountains ......... 51 
CHAPTER Y. 
GEOLOGICAL SEQUENCE OF ROCKS. 
The Rocks not in confused masses — They occur in a definite 
order — Oldest Rocks of the Mountains — The true sequence 
of the Rocks ......... gj 
CHAPTER VI. 
RECENT DEPOSITS AND PLEISTOCENE. 
Marine deposits now forming— Wind-formed Rocks— Sand 
Dunes — Alluvial deposits — Tertiary 92 
CHAPTER VII. 
THE TRIASSIC ROCKS. 
Origin of the name — A three-fold division— The Tlawkesbury- 
Wianamatta Series— The Sandstones— The Shales— The 
Ironstones — Their Fossil contents — The Sandstones and 
Shales belong to the same geological period . . .98 
CHAPTER VII. — ( Continued .) 
THE FOSSIL PLANTS. 
The Hawkesbury-Wianamatta Series — The Fossil Plants — 
Character of the Triassic Flora — Fossil Plants described — 
Classification of Fossil Plants — The Sandstones and Shales 
belong to the same Geological Period — The Narrabeen 
Shales ; their origin and distribution .... 154 
