THE GEOLOGIST. 
MAY, 1860. 
ON CANADIAN CAVERNS. 
By George D. Gibb, M.D,, M.A., F.G.S., Member of the Canadian 
Institute. 
(Continued from iMge 133). 
1. — Caverns on the Shores of the Magdalen Islands. 
On passing the interesting group of islands in the Gulf of St. 
Lawrence, known as the Magdalens, the observer is struck with their 
beautiful and picturesque appearance, which is suddenly presented 
to his view. The cliffs, which vary in height, present equally 
various colours, in which the shades of red predominate ; these, con- 
trasted with the yellow of the sand-bars, and the green pastures of 
the hill-sides, the dai'ker green of the spruce trees, and the blue of sea 
and sky, produce an effect, as Captain Bayfield describes, extremely 
beautiful, and one which distinguishes these islands from anything 
else in the Gulf Such an agreeable picture it has been my own 
good fortune to witness and admire. The striking feature in their 
formation is the dome-shaped hills rising in the centre of the gi'oup, 
and attaining a height of from two hundred to five himdred and 
eighty feet. They are composed of the Triassic or New Red Sand- 
stone formation, which forms their base, being surmounted or topped 
by masses of trap rocks. The highest of the Magdalens is Entry 
Island, with an elevation of five hundred and eighty feet ; its red 
cliffs rise at its north-east point to three hundred and fifty feet, and 
are what they have been described, truly magnificent and beautiful. 
The soft and friable character of the brick-red cliffs forming the 
shores of these islands, with their remarkable capes and headlands, 
have in many places yielded to the force of the waves, and have be- 
come worn into arches and caverns. This is more strikingly mani- 
fest at Bryon Island, which is nearly surrounded by perpendicular or 
overhanging cliffs, wliich are broken into holes and caverns, and fast 
VOL. III. X 
