238 A. S. PACKARD, Jk, ON THE GLACIAL PHENOMENA 



a direction a few degrees east of north. It must be remembered, as Professor Dana has 

 noticed in his remarks on the Mohawk River glacier, that the glacial striae, when following 

 river courses, were made by local glaciers at the close of the period of great continental : 

 glaciers, when the snow line was rapidly ascending, and the mer de glace stood much farther 

 in the interior. 



Such an arrangement of estuary deposits, as noticed below, at the mouth of the Andros- 

 coggin River, occurs also at the mouth of the Saco River, and of the Merrimac, and in fact 

 of all the rivers of New England. In tracing the Androscoggin and Saco rivers from their 

 mouths back to their head-waters, we shall find repeated at intervals along their course, 

 wherever a village rests upon the bank, river terraces, resting on ancient marine beaches' 

 altered from ancient glacial moraines, flanking a former sea-bottom, consisting of marine 

 clays. In tracing up the Androscoggin, these are finely shown at New Gloucester, Lewis- 

 ton, Paris, and Bethel, in Maine. At Bryant's Pond is a fine example of a glacial moraine 

 lake. Its northwestern end lies at the foot of hills rising abruptly around and partly en- 

 closing it, while its southeast shore is composed of a semicircular altered moraine risino- as 

 a barrier between the pond and the river which flows by it a few rods to the eastward. 

 On the sides of all the valleys lying at the foot of the White Mountains are distinctly seen 

 moraine hills, which, lower down, are rewashed and modified into lake terraces, which were 

 but dilatations of the large rivers, now represented by small mountain torrents and streams. 2 

 In passing from Gorham, N. H., to the Glen House we see on each side of the road, fine 

 examples of true glacial moraines which apparently have never been modified by the sea. 

 These moraines, presenting vertical cliffs from fifty to one hundred feet high, of clay and 

 mud and gravel, are mixed in confusion, though near the top of the deposit there is a rude 

 stratification probably similar to what has been noticed in the ancient moraines in the 

 Alps. There is a marked difference between the soft, oozy, treacherous, glacial mud which 

 sticks to the enclosed rounded, worn, and polished boulders, and into which one may sink 

 almost knee-deep, and the tough, tenacious, marine clays of the coast. 



This moraine matter I observed, in ascending the sides of Mount Washington, to be- 

 come gradually freer from the glacial mud, and the soil through which the boulders are 

 scattered becomes more loamy and gravelly. Also, as we ascend the mountain, the bould- 

 ers become more angular. Half way up the mountain, at a point beyond the limits of 

 growth of the deciduous trees, where the spruces grew from 30 to 40 feet high, the drift 

 was almost wholly composed of boulders, one half of which were angular, while the other 

 half were rounded. As we ascend higher the rocks continue to grow more angular, until 

 just beyond the limit of trees, at a height of 4150 feet, both the boulders and gravel are all 

 angular. At this height no foreign boulders of rock differing from the peculiar slate which 

 forms the summit of the mountain, and which, as Prof. Leslie oberves, 3 is not found at the base, 

 were observed. The sides of the mountain, and the summits of Mounts Jefferson, Adams 

 Clay, and Madison, are strewn thickly with angular masses of granite and mica slate contain- 

 ing staurotide in great abundance. The " Ledge " is an embossed and rounded rock 3840 feet 



i By continental glaciers we would not convey the idea of a such seas of ice capping broad areas of thousands of square 



single, broad, unbroken ice-dome extending from one ocean miles. 



to the other, but rather of a system of vast seas of ice capping a See " Hitchcock's Surface Geology," Smithsonian Contri- 



the principal water-sheds of Eastern North America, and butions. We would, however, rather consider the " moraine 



sending branches down the principal valleys. This may be terraces " of that learned investigator, as remodelled ula 



assumed, though many years of observation, in British North moraines, which at a later period formed ancient beaches. 



America especially, are needed to prove the existence of 3 Proc. Amer. Phil. Soc. 



'lacial 



