Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/197

Rh AND CIRQUES IN NORWAY AND GREENLAND. 150

to 1800 feet + the depth of the Waigat, which is unknown. The islets also near the colony of Egedesminde are moutonnees, showing that here also the glaciers once reached the sea.

In Norway I have investigated more closely the former thickness of the glaciers, estimating them from the heights at which I found boulders, grooves, or roches moutonnees on isolated mountains, on islands in the fjords, and along the sides of the fjords. The follow- ing arc the results : —

Varaldso is an island in the middle of the Hardanger Fjord, com- posed of clay-mica-schists and some other slates. The depth of the fjord inside this is, according to the sea-charts, 631 metres. I found a boulder of granite 3 metres long on the island at a height of 305 metres. In the northern parts there are grooves at a height of 457 metres, lioches moutonnees and grooves are seen at a height of 569 metres, which to the eye appears only a few metres below the highest point of the island.

The islands of Sulend lie before the mouth of the Sogne Fjord and rise to a height of 500 metres. The soundings of the Sogne Fjord inside them are the deepest known in Norway, being about 1200 metres over an extent of some 20 miles, the greatest depth being 12-14 metres. The Sulends consist of a conglomerate resting on clay-mica-schists. In ascending the mountain of Pollefjeld (their highest summit) I found boulders of foreign rock on the conglo- merate. The greatest height at which these occurred was 511 metres, and the summit of Pollefjeld was by measurement 529 metres above the sea-level, that is, only 18 metres above the highest boulders. Roches moutonnees abound in these islands ; their lower parts are formed of an undulating rock-surface, and the sides over the sounds are steep and polished, and near the sea not rarely grooved. To these observations numbers from similar localities could easily bo added ; in short, the islets of the Skiirgard along the Norwegian coast are all moutonnees whenever the nature of the rock has allowed this form to be preserved.

lloclies moutonnees are usually found along the sides of the fjords, as well as in the islands, wherever the original surface is un- wcathered; this may be readily seen in travelling along the fjord at some distance from the land: by looking seawards (that is, in the direction in which the glacier moved) the characteristic smooth undulated outlines of the back of the icc-w r orn rocks will be at once recognized ; but on looking up the fjord the steeper sides of the rocks face the spectator, rising one above the other like a series of steps. This structure is rendered most conspicuous when the country is covered by snow, which of course does not rest on the steep faces of these rocks. In the Aurlands Fjord (a branch of the Sogne Fjord) grooves occur at 391 metres and at the higher level of 606 metres above the w^ater. Roches moutonnees appear to continue up to a height of 668 metres. The depth of the fjord below^ is 275 metres.

Along the side of the Stir Fjord, in Hardanger, Professor Sexe * observed groovings 471 metres above the sea, the depth below being
 * Marker efter en Istid, p. 6.