Jenolan Caves. 
241 
the admiration of every visitor. Just as fancy may 
prompt the observer, he finds in the handiwork of 
Nature’s own devising the form of a Gothic cathedral, 
or a Grecian temple with its forest of noble columns. 
Here and there a suggestion of groined arches in 
various groupings calls up visions of a fairy palace, 
some new and startling effects meeting one at every 
turn. And then the almost magic effect of light and 
shade lends an enchantment to those subterranean 
palaces that we may look for in vain elsewhere. 
Geologically, the existence of the caves depends on the 
fact that a bar of limestone runs almost directly across 
a deeply eroded valley — water, the giant sculptor of 
mountains, having found it easier to make itself a 
passage by dissolving the limestones, rather than by 
eroding them to the valley level. Apart from the 
actual features visible in the caves, a geological 
student will find much to interest him, not merely 
around the caves, but all the wav from Mount Victoria. 
Leaving Mount Victoria (on Hawkesbury Sand- 
stone), the road drops down in a few miles through 
the Narrabeen Shales and the higher beds of the 
Permo-Carboniferous, and through the Upper Marine 
beds, down to the granite at Hartley. Some 
interesting dykes cut through the granites hereabouts. 
Many varieties of granite are plentiful on the Cox 
River close by, red, grey, and blue-black granite being 
common. Graphic granite, felsite, and diorite are also 
abundant. Amongst the sedimentary rocks, chert, 
conglomerate, grit, sandstone, mudstone, clay shale, 
