Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/950

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.

(3.) By this time the country was much higher than now, and, the land being connected with the Continent, the bulk of the present flora and fauna crept into it from various quarters, though the alpine plants still kept possession of the higher mountain-regions during a great portion of this epoch. The red deer, the great Irish elk, great wild bull, the musk-ox, the brown bear, and the reindeer in all probability appeared about this time, though I am not altogether sure that some of them did not hold possession of the tops of the mountains even during the period of submergence.

(e.) A depression now took place, and the estuarine beds or carses of the Scottish rivers were formed. Much of the fossiliferous boulder-clay formed as I have described it is now under the sea ; off the coast we continually dredge up remains of its fauna. Man had also by this time got into the country ; and it is possible that he was there during the former epoch, having travelled overland from the Continent at a period when the Thames was a tributary of the Rhine, and our other rivers had not settled down in their beds, though for long periods previous to this the general contour of our country was as it is just now, only its boundaries were not settled.

(£.) The land after this seems to have risen, in all probability to its present level ; for we have no certain evidence that since the dawn of history there were any oscillations of level. These latter changes I have touched but slightly on, as they do not concern our subject so much as the former.

Conclusion. — I have thus given what I honestly conceive to be a correct description of glaciation in Greenland, with logical deductions regarding glaciation in Britain and, by context, in northern Europe. The paper resolves itself into two parts : — 1st, fact ; 2nd, theory. Still our facts are too few to allow any theory to be more than tentative ; and it is only by making frequent ventures, and being content to see our first efforts fail, that we can ever arrive at any conclusions regarding the glacial epoch in Scotland. Though we have a number of so-called facts ready-made to our hand, yet the difficulty is to believe them, simply because the recorders, though perfectly honest and upright, see these facts through a preconceived theory, and, unknown to themselves, twist them into a form which will support their views, and omit (unintentionally) to record the very things most necessary to be observed. I conceive, however, that we are on the right track, and that it is only by long observation of the glacial system of Greenland (because in Spitzbergen the glaciers are on such a small scale as to show us glaciation but imperfectly 1 ) that we can ever arrive at a sound knowledge of the

that of theory founded on ascertained facts. An ancient river-bed shows that at the time of its formation Scotland must have been at least 260 feet higher than the present level ; and the river which flowed in it most likely was a tributary of the Rhine. Whether we can agree with Mr. Croll, however, in believing the glacial "period" to have been a succession of heats and colds, requires further consideration of facts.

1 Spitzbergen, like all the high Arctic islands of any size, has an "inland ice " and glacier-system of its own ; but it is too intersected by fjords and broken