CHAPTER VI 
The Mediterranean Basin and Submerged River- Valleys 
EXPLANATION TO ACCOMPANY PLATE V 
HAT this great inland sea, at least in- its western half, has partaken of the vertical 
oscillations which affected the coast of Western Europe and Africa will be readily understood. 
The general elevation of the ocean-bed and adjoining lands which have been shown to have 
taken place in the case of these countries must necessarily have extended into the adjoining 
regions of the Mediterranean coasts and sea-bed. But while this is the case, it is not to be expected 
that the physical features of these submerged lands should be as clearly developed within the confined 
area of the Mediterranean basin as along the Atlantic coast, confronted by the prevalent westerly winds 
originating powerful wave action on an exposed coast. 
The coastal features of the Atlantic, both submerged and above the sea-level, including the 
Continental Shelf formed during a long pause in the vertical movements of the crust, and the more or less 
precipitous descent into the abyss, are less pronounced in the case of this inland sea. But nevertheless the 
old submerged coast, at the edge of the Continental Shelf, is found to descend into deep water by a 
broken slope down to a depth of 1000-1200 fathoms, when it gives place to the abyssal region, which 
descends to depths of about 1500 fathoms, or gooo feet. As a consequence of this restricted area, the 
submerged river-valleys are also less clearly definable than those off the Atlantic coast of the Peninsula.? 
The only submerged channels of the Mediterranean which I have been able to trace on the Admiralty 
Charts are those of the Ebro and Rhone, together with that discovered by the late Admiral Spratt, 
between “‘ Adventure Bank” and Cape Bon. But, in addition to these, we have to note the remarkable 
discovery of similar channels recorded by the late Professor Arturo Issel off the northern coast of the 
Gulf of Genoa. These are of especial value as tending to confirm the results arrived at by the author— 
coming from an independent source—regarding the Geological period of the great uplift. 
The following are some details regarding the submerged river-beds of this great inland sea : 
1. The Submerged Channel of the Ebro—The number of soundings off Cape Tortosa, tor the purpose 
of determining the course of the submerged valley of this river, are not as numerous as might be wished ; 
still the inward bend of the contours from that of 40 fathoms down to that of 1000 fathoms immediately 
opposite the mouth of the river, cannot be mistaken as other than indications of the course of the channel. 
Along the Gulf of Valencia the representative of the Continental Shelf is unusually broad and well defined, 
breaking off at the 100-fathom contour at a distance (opposite Valencia) of 60 miles from the coast, and 
with a very steep descent for a depth of 500 fathoms, beyond which it cannot be traced. 
2. The Submerged Channel of the Rhéne.—This channel is perhaps even more definitely indicated than 
that of the Ebro by the inward bend of the isobaths extending from 100 to 1200 fathoms. The channel 
commences directly south of the city of Marseilles at a distance of about 30 miles to the east of the point 
where the river itself now enters the sea; but it is in a direct line with the course of the main stream 
below Arles ; and between the two points the submerged channel may be supposed to pass through the 
Continental Shelf, though not apparent by the plumb-line owing doubtless to silting up. The Shelf 
1 They were found, in fact, too insignificant for insertion on the map of a small scale. 
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