Page:A Voyage of Discovery and Research in the Southern and Antarctic Regions Vol 1.djvu/146

72 the larger of these seams are marked on the annexed plan. Whether the coal is in sufficient abundance ever to be of commercial importance we had not the opportunity of ascertaining: but at the present day, when steam vessels are traversing every portion of the ocean, it may not be unworthy a more extended examination, for in no situation would it be more desirable to have a coal depôt than at this island, lying, as it does, immediately in the high road to all our Indian and Australasian colonies, abounding with excellent harbours, and at a convenient distance from the Cape of Good Hope. For many interesting geological details respecting the formation of the land in the vicinity of Christmas Harbour I must refer to the following report of Mr. M’Cormick, who was most indefatigable in its examination:—

"The northern extremity of the island, visited by the expedition, is entirely of volcanic origin: the bold headlands of Capes Cumberland and François present a striking appearance from the sea; the trap rocks, of which they are composed, form a succession of terraces nearly horizontal, which, on first making the land, have a very striking 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 generally from 500 to 2500 feet. Many of the hills are intersected by trap dykes; these dykes are