Extinct Glaciers of Switzerland
WE have seen in the preceding chapters that the mountains of Scandinavia, Scotland, and North Wales have served, during the glacial period, as so many independent centres for the dispersion of erratic blocks, just as at present the icecovered continent of North Greenland is sending down ice in all directions to the coast, and filling Baffin's Bay with floating bergs, many of them laden with fragments of rocks.
Another great European centre of ice-action during the postpliocene period was the Alps of Switzerland, and I shall now proceed to consider the chronological relations of the extinct Alpine glaciers to those of more northern countries previously treated of.
The Alps lie far south of the limits of the northern drift described in the foregoing pages, being situated between the 44th and 47th degrees of north latitude. On the flanks of these mountains, and on the subAlpine ranges of hills or plains adjoining them, those appearances which have been so often alluded to, as distinguishing or accompanying the drift, between the 5O'ch and 70th parallels of north latitude, suddenly reappear and assume, in a southern region, a truly arctic development. Where the Alps are highest, the largest erratic blocks have been sent forth; as, for example, from the regions of Mont Blanc and Monte Eosa, into the adjoining parts of Switzerland and Italy; while in districts where the great chain sinks in altitude, as in Carinthia, Carniola, and elsewhere, no such rocky fragments, or a few only and of smaller bulk, have been detached and transported to a distance.