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2nd. That a great current, originating, probably, in the 
union of a North Polar current, with a modification of the 
present Gulf-stream, was constantly setting in upon the 
northern and western shores of Great Britain and Ireland, 
with the climate of an Arctic character. 
3rd. That a gradual submergence of the area of the British 
Isles took place to the extent, in some parts, of at least 
1,600 feet ; — and subsequently a gradual emergence of the 
same extent. 
The submergence is chronicled by the scratched rocks, and 
boulders of the true boulder clay series. 
The emergence is marked by more elevated terraces or 
extended platforms of rolled boulders and gravel, sometimes 
being merely a re-distribution of the materials of the boulder- 
clay; sometimes the pebbles of adjacent rocks regularly 
stratified. 
4th. That during the uprising, the severe and rigorous 
conditions of the climate were modified ; erratics from more 
distant localities were dropped by the grounding and melting 
of ice-bergs; while the scratching and grooving action of 
littoral ice in a great measure ceased. The marks of up- 
rising on the east and west coasts of Great Britain and the 
Isle of Man, are the last traces of the physical condition of 
the country during the glacial epoch. 
Other subsequent minor changes have occurred : — the 
erosion by the sea, in the separation between the British 
Isles and the continent of Europe — a slight depression, to a 
certain extent, about fifteen to twenty feet below the present 
high water level, as indicated by water-worn caves and in- 
land cliffs. Lastly, a slight subsequent elevation, in some 
situations, which has left a low line of beach above the 
present sea level, to the base of the pleistocene cliffs, inland, 
forming rich alluvial tracts on what were formerly the sands 
of wide estuaries. 
