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IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 
the widening of the valley cn the harder rocks, there was, no 
doubt, a far more extensive broadening upon the red beds and 
granite, but the valley floor on those rocks has been lowered 
many thousand feet, at least near the river, and the higher level, 
if it still survives cn them, is to be seen only in the foothills of 
the adjoining mountains.” 1 
The intermediate plain above referred to, and its correlation 
with the section of the river above the gorges will have an im- 
portant bearing on the unravelling of Yangtze history. At 
present there are no data available for such correlation. There 
is, however, a region beyond the gorges which is marked by ridges 
Fig. 5. At Suifu, showing two ridges,, which are the . two limbs of an 
anticline Which has “broken down to depths of several hundred feet, 
leaving the limbs projected a mile or more apart, with open valleys 
between.” 
standing out above the surrounding country to heights of 500 
to 1,000 feet. Near the city of Suifu one can stand on a hill 
and look across and along such ridges, fiat and even as far as 
the eye can reach. The Yangtze and its tributaries pay little at- 
tention to them, for at one point the eye can follow the course 
of the main river as it cuts through three or four gaps in these 
ridges. Where tributaries enter the main stream they have cut 
U-'ailey Willis. Research in China, Vol. I, 334. 
