31 
Geology of Kerguelen s Land . 
upon, but tlie succession of terraces, nearly horizontal, 
to its summit, sufficiently indicate its basaltic structure 
to be the same as that of the main land. 
The range of mountains flanking Cumberland Bay, 
on each side, generally presents the same trap terraces 
as in Christmas Harbour. 
Six miles and a half up the bay are two inlets, nearly 
opposite to each other : the one on the south side is a 
mile and a half deep, a mile broad at its widest part, 
and one-third at its entrance. The trap rocks bounding 
this bay differ from the others, in containing drusy 
cavities of beautiful quartz crystals; many fine fragments 
of which were scattered about the surface of the rocky 
ledges. 
At the top of the bay is a remarkable hill, between 
three and four hundred feet in height, constituted of an 
igneous arenaceous rock, with a slaty fracture confusedly 
intermingled with greenstone and basalt, having a crater¬ 
shaped summit, filled by a lake 200 yards long and 150 
broad, three feet deep near the margin, and the centre 
covered with thin ice. It is surrounded by an irregular 
wall of greenstone, from five to twenty feet in height. 
The water finds an outlet by a water-course down the 
south-east side of the hill, forming a small cascade in its 
first descent from the lake. 
The ascent of the hill on the south-east side is by a 
narrow gorge, three feet wide, nearly perpendicular, and 
through a mass of the hard arenaceous rock, having a 
tendency to the prismatic form. On attaining the 
summit, a quantity of loose fragments of slate strew the 
surface. Near the centre a basaltic dyke, 3 feet wide, 
and having a south-east and north-west direction, divides 
an amorphous mass of arenaceous rock from the green¬ 
stone on the north side. 
