Effect of Glacial Waters 
47 
its present flood-waters is about six feet, proved by a fern-cov¬ 
ered calcareous deposit, projecting some fifteen feet, caused by 
a spring (Shower-Bath Spring) on the side of the wall, seven or 
eight miles above the mouth, which is never permitted by the 
floods to build nearer the floor of the canyon. A suspicion 
arises, on contemplating some of these apparent discrepancies, 
that the prevailing conditions of corrasion are not what they 
were at some earlier period, when they were such that it was 
Bad Lands on Black’s Fork of Green River. 
Photograph by U S. Geol. Survey 
rendered more rapid and violent; that there was perhaps an 
epoch when these deep-cut tributary canyons carried perennial 
streams, and when the volume of the Colorado itself was many 
times greater, possessing a multiplied corrasive power, while 
the adjacent areas were about as arid as now. At such a time, 
perhaps, the Colorado performed the main work of the inner 
gorge, the Kanab, and similar affluents, their deep now rather 
evenly graded canyons. Such an increase of volume, if we 
suppose the aridity to remain as now, could have come about 
