nOMMtJNrCATION DE M. WARREN UPIIAM 
241 
*"haracter and seqiiencc, first, a comparalively long continucd 
’^plift, whicli in its culmination appears to liavc givcn a liigh 
plateau climate witli abundant suowfall forming an ice-sheet, 
'^bose duration extended until tlie land sank somewhat lower 
*an now, leading to amelioration of the climate and tlie depar- 
ot the ice, Ibllowed by re-elevation to the présent level. 
“6 coincidence oF these great earth movements witli glaciation 
^sbirally leads to the conviction that they were the direct and 
®afficient cause of the ice-slieets and of their disappearance. 
"lhe epeirogenic movements of the countrics whicli bccainc 
s aciated were ouly a portion of wide-spread oscillations of con- 
cntal areas during the closing part of Tertiary time ami the 
^‘isuiug much shorter Ouaternary era. Not only was northwest- 
Europe uplifted thousands of feet, but probably ail the 
""Csteru side of Europe and Africa shared in this movcmcnt, of 
‘‘Cil we bave the most convincing proof in the submerged 
^^lannel of the Congo, about four hundred miles south of 
^ cquator. From soundings for the sélection of the route for 
■‘^ubinarine cable to connect commercial stations on the Afri 
can 
coast, Mr J. Y. Buchanan ^ found this channel to extend 
miles into the océan, to a dcpth of more than 6000 feet. 
'c twenty miles of the Congo hâve a depth from 900 to 
I , feet. At tlie mouth of the river its width is three miles, 
the *^cplh 2000 feet. Thirty-five miles olî shore the width of 
Submerged channel or canon is six miles, with a depth of 
^"iciO feet, its bottom being nearly 3000 feet below the sea 
so side. Fifty miles from the mouth of the river, the 
tv| submarine continental slope is nearly 3000 feet, 
re^^^ *'he bottom of the olcl channel is at 6000 feet. This very 
_ ^hle continuation of the Congo valley far beneath the sea 
lik those of the Hudson and St. Lawrence rivers, and 
but submerged vallcys on the coast of California ; 
*'bc Congo rcaches to a greater depth than these of North 
de even exceeds the Sogne fjord, the longest and 
^Û80 Norway, which lias a maximum soundiug of 
less ■^''^‘^Iher deep submariiie valley, called the « Bottom- 
having soundings of 2700 feet, is described by Buclia- 
he African coast, 350 miles north of the equator, and 
^ CS that a similar valley e.xists in the Southern part of the 
S 
'-ottish Geograplilcal Mag’azinc, vol. III, 1887, p. âlT-a.SS. 
CONCR. CÉOL. INTERN. 
16 
