CHAPTER II 
The Continental Platform 
EXPLANATION TO ACCOMPANY PLATE I 
NE of the most recent and remarkable discoveries regarding the features of the submerged 
region surrounding the British Isles and European Continent is the fact that these land 
areas do not rise abruptly from the profound depths of the Atlantic Ocean, but are separated 
therefrom by a continuous belt, or platform, of varying breadth and comparatively slight 
depth, known as “the British and Continental Platform.” 
This feature was originally recognised by the late Mr. Godwin-Austen as far as the region outside 
the Bristol Channel is concerned; and was brought before the British Association by the late Mr. 
Hudleston and the author at the meeting at Bristol in 1898.’ In the chart which accompanied Mr. 
Hudleston’s communication, the outer margin of the platform was accurately traced; but the gaps 
showing the crossing of submerged river-valleys, descending from the interior lands, were ignored ; these, 
however, were indicated for the first time on the chart exhibited by the author at the same meeting.” 
Extent of the British Shelf—The western margin of the British Platform as shown on the adjoining 
map (Plate I.) corresponds, very nearly, with the isobathic contour of 100 fathoms (600 feet) running in 
a line from the Vidal Bank opposite the western coast of Scotland and Ireland at a variable distance 
southwards ; and enclosing a remarkable bay or gulf having its apex at lat. 59° N.° The waters of the 
Platform bathe the shores of the Irish Sea and the English Channel and spread over the North Sea to the 
coast of Norway ; and, as shown by Professor J. W. Spencer, extend to Iceland and Greenland ; owing to 
which the fauna and flora of Europe are largely represented in those high latitudes, as a comparatively 
slight elevation would establish a land connection. The Platform seldom exceeds 100 fathoms in depth, 
and its floor is largely overspread by silt, sand, and gravel, with shells and various marine forms of animals. 
Its shallowest part occurs at the Strait of Dover, which at one period formed the water-parting between 
the North Sea and the English Channel ; throwing off the rivers in opposite directions, towards the 
Arctic Ocean on the one hand and the Atlantic Ocean on the other.® 
The Continental Slope or Declivity—From its margin as above described, the Continental Slope descends 
to profound depths, by a descent more or less rapid, often approaching the vertical ; and, as will be shown 
by succeeding charts, reaches at its base a depth of 6000 to 7000 feet (1000-1200 fathoms), as indicated 
by the soundings. For the proof of this we have to point to the position of the submerged river-valleys, 
1 Hudleston, “Eastern Margin of the North Atlantic Basin,” Trans. Brit. Assoc., 1898, p. 881. Hull, “On the Sub-Oceanic Physical 
Features of the North Atlantic,” ibid. p. 879. 
2 ‘The omission of these gaps was probably due to oversight on the part of the cartographer employed by Mr. Hudleston ; not to Mr. Hudleston 
himself. 
8 This I propose to call “’The Spencerian Gulf,” in honour of my American fellow-worker Professor J. W. Spencer of Washington, who con- 
tributes Chapter IX. to this monograph. 
4 The American Geolgist, vol. xxxv., March 1905, p. 153. There can be no doubt that the North Sea bed is traversed by river-valleys 
emptying into the Arctic Ocean, but owing to silting up they are undistinguishable by means of the soundings on the Admiralty Charts. 
5 Though the margin of the shelf off the coast of Scotland nearly coincides with the 100-fathom contour, yet in front of the English Channel 
it increases in depth to 180-200 fathoms. 
4 
