The Submerged Terraces and River- Valleys of 
the British Isles and Western Europe 
CHAPTER I 
Introductory and Historical 
HE appearance in the year 1895 of Professor Spencer's Memoir on “The Reconstruction 
of the Antillean Continent”! marks an epoch in Oceanic Geography. It is true that 
numerous writers, such as Professor Wyville Thomson, had investigated the form and depth 
of the floor of the ocean, and to a certain extent the streams which open out into its waters 
at various points. But the application of deep-sea soundings as a key to unlock the mysteries of the 
ocean-bed, to restore systematically its form and features, its terraces and submerged river-valleys, 
wherever such soundings had been made, were for the first time demonstrated by Spencer in that 
remarkable Memoir. In this work the author shows that the group of the West Indian Islands 
are only the emergent heights of a continental area which united the two Americas and enclosed 
the deeper portions of the Caribbean Sea and the Gulf of Mexico in the form of inland seas, 
bounded by two submerged terraces, those of the Continental Shelf and the Blake Plateau, which are 
continued round the West Indian Islands and the Gulf of Mexico, and stretch along the coast of the 
North American Continent to the Newfoundland Banks. He also showed that these terraces are traversed 
by the prolongation of the existing rivers which enter the northern shore of the Gulf of Mexico to depths 
of about go0o or 10,000 feet ; and he maintains that the physical features determined by the soundings 
can only be explained by supposing an uplift of the whole region to the extent of 10,000 feet as compared 
with the present sea-levels ; owing to which uprise the waters of the present Gulf Stream were for a time 
shut out from the Gulf of Mexico. As regards submarine extension of the Hudson River, Professor 
Spencer’s investigations were anticipated by America’s great geologist, Professor James D. Dana, and by 
Admiral Charles A. Chester, U.S.N., whose investigations were made known by Mr. A, Lindenkohl. 
These works are fully recognised by Professor Spencer himself.’ 
From the above statement it will be seen that Spencer may rightly claim to be the founder of a new 
branch of Science under the name of Sus-Ocrzanic Puysiocrapuy, which we may interpret as the 
application of the sounding line to the representation of the physical features of the ocean-bed ; and not 
only in the Atlantic, but throughout all parts of the ocean where such soundings have been carried out 
to a sufficient extent to warrant their use for that purpose. Along the eastern coast of the United States 
and the British Dominions, as also along that of the British Isles and Western Europe, these soundings 
have been completed in sufficiency of number and with absolute precision by the respective Governments, 
including those of the Prince of Monaco ; and by the detailed soundings of the Cable Companies, to 
enable us by the aid of isobathic contours to restore with approximate accuracy the varied features 
1 Bull. Geol. Soc. Amer. vol. vi. 
2 “Submarine Valleys off the American Coast and in the North Atlantic,” Bull. Geol. Soc. Amer. vol. xiv. (1902). 
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