Geology of Kerguelen's Land * 
27 
Art. V. Geological Remarks on Kerguelen's Land. By 
Robert M‘Cormick, Esq., Surgeon of H. M. S. 
Erebus. 
The northern extremity of the Island, visited by the 
Expedition, is entirely of volcanic origin : the bold head¬ 
lands of Capes Cumberland and Francois present a 
striking appearance from the sea; the trap rocks, of 
which they are composed, forming a succession of ter¬ 
races, nearly horizontal, which, on first making the land, 
have a strong resemblance to stratified sandstone, or 
limestone. 
Basalt is the prevailing rock, assuming the prismatic 
form, and passing into greenstone, and the various 
modifications of amygdaloid and porphyry. The general 
direction of the mountain ranges inclines to the S. W. 
and N. E., varying in height from 500 to 2500 feet. 
Many of the hills are intersected by trap dykes, usually 
of basalt, and of very frequent occurrence. Several 
conical hills, with crater-shaped summits, evidently have 
once been volcanic vents. 
Three or four very remarkable detached hills, composed 
of an igneous kind of arenaceous rock, forming piles of 
loose slaty fragments, through which the mass protrudes 
in places in prismatic columns, occur in Cumberland 
Bay. 
The vast quantities of debris which have accumulated 
at the base of the hills, in many places to the height of 
two or three hundred feet and upwards, afford strong 
evidence of the rapid disintegration which this land is 
undergoing, from the sudden atmospheric changes and 
vicissitudes of climate to which it is exposed. 
The whole Island appears to be deeply indented by 
bays and inlets, and the surface intersected by numerous 
small lakes and water-courses ; these becoming swollen 
