CHAPTER X. 
SILURIAN. 
SILURIAN SLATES TILTED FROM ORIGINAL POSITION 
IN CONTRAST WITH PERMO-CARBONIFEROUS TRUE 
SLATES AND FLAGSTONES — ORIGIN OF THE SILURIAN 
LIMESTONE— SOME LIMESTONES OLD CORAL REEFS 
CAVES CAVE-SHELTERS — LIMESTONE CAVES — STALAC- 
TITES — STALAGMITES — THE JENOLAN CAVES. 
One of the first characters of the Silurian rocks that 
will be noted is the fact that their stratification layers 
are, as a rule, highly inclined, making the strata 
appear to stand on end. This character is fairly per- 
sistent over the Silurian areas of the colony ; so much 
so, that we come to look for vertical strata as particu- 
larly distinctive of Silurian Slates. It may be remarked, 
however, that in other countries — notably in parts of 
North America and Russia — Silurian rocks are very 
little disturbed, and often rest in their original hori- 
zontal position. The nearest locality to Sydney where 
rocks of Silurian age may be studied is the country 
around the Jenolan Caves. In the cuttings on the 
road down Cave Hill, on the way to the caves from 
Mount Victoria, slates can be seen highly inclined 
as shown in Fig. 62. This contrasts strongly with the 
