10 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
founded with the deeper canyon further south, where the same creek 
cuts down through the Kanab plateau to the Colorado river in the 
Grand canyon. The canyon in the Trias is of interest in giving an 
open section of nearly the whole Triassic formation, and in exhibiting 
the alternation of aggrading and degrading action by a stream in an 
arid region. 
The Triassic strata are much more variable in texture than the 
Jurassic. They present many alternations from weak and thin-bedded 
muddy sandstones tv thick, massive, resistant sandstones ; and as a re- 
sult the walls of this canyon are characterized by numerous benches. 
Cross-bedding is very common, though not on so remarkable a scale 
as in the Jurassic. The red color is very strong in many beds. It 
seems at first sight to prevail throughout, but a closer examination 
shows that some of the cliffs are made of a gray sandstone, whose 
outcrops are stained by the red wash from the overlying slope. 
The uppermost of the red beds are seen in tle base of the buttes 
that front the Jurassic escarpment; the Triassic platform is violently 
colored with them over large areas. The hne of the ground is so streng 
and so little concealed by the scanty vegetation that we saw passing 
cumulus clouds with a distinctly ruddy tinge on their under side, due 
to light reflected from the colored earth. 
Kanab canyon has two terraces of well-stratified alluvium, usually of 
fine texture and containing lateral unconformities such as are to be 
expected in the deposits of aggrading streams; yet on the whole the 
stratification is remarkably even. The higher terrace is eighty or one 
hundred feet over the stream bed; it is less continuous than the lower 
one, which stands from forty to seventy-five feet over the stream. The 
channel below the lower terrace is the work of a series of floods begin- 
ning in the summer of 1883; a great part of the alluvium then accumulated 
along the valley was rapidly swept away. This seemed to be so excellent ~ 
an example of the spasmodic action of floods in arid regions that I made 
special inquiry about it, and through the assistance of E. D. Woolley of 
Kanab secured an account written by his townsman, Herbert E. Riggs ; 
the following is an abstract of the original :— 
“ At the time of the settlement of Kanab, in 1871, the creek ran at the level 
of the lower one of the two terraces that are now seen along its canyon. The 
meadow was about a quarter of a mile wide, with much swamp occupied with 
flags, bulrushes, rabbit brush and willows. This condition prevailed for 
about seven miles from the Trias escarpment (Vermilion cliffs) northward up 
the canyon to where the stream headed, and for about five miles southward, 
