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The shifting of levels in the morainic material would account for the drying up of some lakes and the terrace formations in others, whilst curious trenches in the ground are obviously due to cracks in the ice beneath. We are now quite convinced that the queer cones on the Ramp are merely the result of the weathering of big blocks of agglomerate. As weathering results they appear unique.
Such tumultuous hills and hummocks, set with depressions of all shapes, which usually are without outlet and are often occupied by marshes, ponds, and lakes, surely cannot be the work of running water. The hills are heaps of drift, lodged beneath the ice edge or piled along its front. The basins were left among the tangle of morainic knolls and ridges as the margin of the ice moved back and forth.
The central area of the Malaspina is also free from debris; but on the outer edge large quantities of englacial drift are exposed by surface melting and form a belt of morainic waste a few feet thick and several miles wide, covered in part with a luxuriant forest, beneath which the ice is in places one thousand feet in depth.
In almost every valley of the Sierras and the Rockies the records of these vanished ice streams may be found in cirques, glacial troughs, roches moutonnecs, and morainic deposits. It was during the Glacial epoch that Lakes Bonneville and Lahontan were established in the Great Basin, whose climate must then have been much more moist than now.
The journey proved to be one of the most interesting he had made in this country with reference to local glacial phenomena. Compass in hand, he followed the extraordinary ridges of morainic material lying between Bangor and Katahdin, to the Ebeene Mountains, at the foot of which are the Katahdin Iron Works.
A great deal of the underlying ice is exposed, but we had doubts as to whether this ice was not the result of winter drifting and summer thawing. We have a little difference of opinion as to whether this morainic material has been brought down in surface layers or pushed up from the bottom ice layers, as in Alpine glaciers.
Signor Gastaldi has shown that all the ponds in that area consist exclusively of what M. de Mortillet has denominated morainic lakes, i.e. caused by barriers of glacier-mud and stones. Fifthly. The deposits alluded to on the borders of the Lake of Zurich are those of Utznach and Durnten, situated each about 350 feet above the present level of the lake and containing valuable beds of lignite.
Some lakes are due to the blockade of ancient valleys by morainic delms, and this class includes many of the lakes of the Adirondacks, the mountain regions of New England, and the Laurentian area. Still other lakes rest in rock basins scooped out by glaciers.
To-day I walked round the shores of the North Bay examining the kenyte cliffs and great masses of morainic material of the Barne Glacier, then on under the huge blue ice cliffs of the Glacier itself. With the sunset lights, deep shadows, the black islands and white bergs it was all very beautiful.
In such cases it is possible that the river was pushed to one side of its former valley by a lobe of ice, and compelled to cut a new channel in the adjacent uplands. A section of the valley may have been blockaded with morainic waste, and the lake formed behind the barrier may have found outlet over the country to one side of the ancient drift-filled valley.
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