Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/937

 down infrajacent rocks and at the same time get grooved in a corresponding direction. If the Greenland glacier does not reach the sea, then the programme of the Alpine glacier is repeated ; but when the lower end breaks on reaching the head of the fjord, then a different result ensues. The terminal moraine {if there is any; for none comes over the inland] ice, which leads me to believe that it does not rise in mountains ; and often the glacier is so short as to take little or none from the sides of its valley) floats off on the surface of the iceberg, and the moraine profonde either drops into the sea, or is carried further on in the base of the iceberg : very frequently this moraine profonde is composed of boulders and gravel, and it is rare that they are not dropped before the berg gets out of the fjord. The berg itself very often capsizes in the inlet and deposits what load it may have on its surface or bottom at the bottom of the sea ; and when it gets out of the inlet, as I have already described, it often ranges itself in the outside ice-stream ; and if it there capsizes, then the boulders lie on the bottom there, so that, if the floor of the sea were raised up, a long line of boulders would be found imbedded in a tenacious bed of laminated clay, with fossil shells and remains of other Arctic animals, skeletons of seals, heaps of gravel here and there, and so on, in what would then be a mossy valley, most likely the bed of some river. Again, allow me to remark that a berg may not capsize by pieces breaking off from above the water, but it may also lose its equilibrium (as is well known) by being worn away, as is most frequently the case, at the base, or (as is less known) by pieces calving off from below. If the berg ground on a bank or shoal, or in any other water not deep enough for its huge bulk to float in, it will often bring up from the bottom boulders, gravels, &c, deposited by former bergs, and carry them on until this material is deposited elsewhere ; when grounding, it will graze over the submerged boulders, or rocks just under water, grooving them in long grooves ; for an icebeg, it cannot be too often remembered, is merely a mountain of ice floating in the sea. In my earlier voyages in the Arctic regions I was rather inclined to underrate the transporting-power of bergs, as I saw but few of them with any earth, rocks, or other land-matter on them. Though still believing that this has been exaggerated to support their theories by some writers ignorant, unless by hearsay, of the nature of icebergs 1, I am inclined to think that I was in error.

Towards the close of my voyage, in 1861, I had occasion to ascend to the summit of many bergs when the seamen were watering the vessel from the pools of water on their summits; and I almost invariably found moraine, which had sunk by the melting of the ice into the hollows, deep down out of sight of the voyager sailing past, but which would have been immediately deposited if the berg had been capsized. In 1867 I saw many bergs with masses of rocks on them, and only at the mouth of the Waygatz one

1 I have found, however, that much of the " discoloration " in bergs is caused by the brown leaves of the Cassiope tetragona and other plants, growing among the rocks abutting on the glaciers, and blown down upon them.