THE GLACIAL DRIFTS AT MUSWELL HILL AND FINCHLEY.

I.

Introductory.

The presence at Muswell Hill of certain mysterious memorials, connected in some way with the great Glacial Period of pre-historic times, was first made publicly known in the year 1835. At a spot in Coldfall Wood, just beneath the vegetable soil, an eminent London geologist, Mr. N. To Wetherell, of Higbgate, discovered a strange accumulation of fossil remains, consisting of miscellaneous rocks, shells, teeth of fish, and bones of saurians of extinct species, evidently brought hither by some unknown agency from the formations of various northern areas of England .

The discovery was an eventful one. It gave to Middlesex and the adjacent counties north of the Thames a new place in the physical history of the country. Henceforth it was concluded that the southern lowlands of England, as well as the mountains of Wales and the northern counties, showed traces of their former occupation by glaciers, and perhaps a glacial sea.

The favourite rural stop just outside the Town, which shares with Highgate and Hampstead the title of the Northern Heights of London, has ever since had an interest and charm in addition to its landscape attractions. It has now become widely and popularly associated with that great period of climatal change when the glacial conditions of the Arctic circle descended as far south as the latitude of London.


Preparation For A Visit To Muswell Hill And Finchley.

Where shall the stranger to Muswell Hill and Finchley look for these remains of Glacial England; and what shall he look for ? How shall he recognise these remarkable memorials when he sees them, and read their wonderful history?

Fortunately, the locality over which these glacial relics at North London are spread is now far more accurately known. Since the days of the strange discovery in in1835 in Coldfall Wood, railways, cemeteries, brick pits, and excavations of various kinds, have afforded ample opportunities for exploration. This glacial area has now been mapped, and has become a familiar resort for the field-geologists of London . And yet the visitor would certainly be disappointed if he went without some general instruction and guidance.

The preparation required for a visit to this interesting region is of a two-fold character. In the first place, the. visitor should possess a general idea of the great events of the Glacial Period itself. The glacial memorials at Muswell Hill and Finchley can only be recognised and understood in the light of the great occurrences in the physical history of England in which those memorials originated. With this information, the visitor will find himself an intelligent eye-witness of what the Glacial Period has left behind it in the environs of London .

Accordingly, for the information of strangers to the subject, a brief outline of the main facts of the great Glacial Period, so far as they concern our own island, is here prefixed as introductory to a detailed, account of the glacial accumulations of our district.

Historical Outline of the Great Glacial Period, or Age of Ice, in England.

The following is the series of events in which the glacial remains at Finchley and, Muswell Hill had their origin:

I. A gradual coming on of an Arctic climate, accompanied by a subsidence of the land. The occupation off the higher grounds, and eventually of the northern parts of Britain and the whole of Wales, by glaciers, and by a general ice-sheet which terminates in the sea; a state of things which now prevails in Greenland and on the Antarctic Continent. The ice, moving for the most part southwards, wastes the ground over which it travels, disintegrating the rocks with their fossils, and accumulating the material at its seaward termination in the form of a moraine. Much of this ice being below the sea-level, the sea is blocked out from areas which it would otherwise occupy.

II. As theses, advances, the land-ice gradually retires, leaving its moraine at each stage of the recession to be distributed over the sea-bottom. In this way the land becomes covered by the sea, which in one part of our island had a depth of at least 1.400 feet, as shown by the presence to-day of shells of the glacial sea on a Welsh mountain at this height; and eventually, only an archipelago of ice-clad islands remains above the waves. The sunken country forms the floor of the glacial sea, on which ice-bergs and rafts deposit 'heir burden of transported rocks and of organic remains torn from such rocks.

III. The land, emerges from the glacial waters, tile late sea-floor now forming the new land-surface, and.the land becomes occupied with vegetation and large animals. Then comes a time when glaciers accumulate in the valleys of the mountain districts. Finally this is followed by our present temperate

Such is the great series of events in the physical history of England which throw light on the once mysterious glacial drifts of Coldfall Wood and elsewhere, and render them intelligible. With these grand data to start from, the following conclusion is arrived at with regard to the drifts of our district:­

The tract of glacial ground at Muswell dill awed Finchley is nothing less than a remnant of the sea-bed of the great Glacial Period. It was accumulated when the country was submerged beneath an icy sea.

This is the great fact which the visitor to the spot must realise if he is to recognise the glacial drift, and to understand its nature and origin.

Today, this old sea-bed at Muswell Hill and Finchley, from which the waters long ago retreated, serves as a land surface, and supports terrestrial life. But it still contains within it, as we shall see, all the strange materials which tell of its accumulation beneath the glacial waters.

 

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