112 GUIDEBOOK OF THE WESTERN UNITED STATES. 
Beyond this conglomerate is a wide area occupied by a thick succes- 
sion of light-colored shales, and in the distance are scattered buttes 
of still higher red sandstone (the Wingate), capped by small rem- 
nants of old lava sheets. Some of these lava buttes are very promi- 
nent features in the landscape far to the northeast of Winslow. The 
Moencopie formation extends northwest of Winslow and Moqui siding 
in a broad belt down the valley of the Little Colorado, which finally 
cuts down into the underlying limestone (the Kaibab). West 
of Winslow the train leaves this valley and climbs gradually to 
the Arizona Plateau. This extensive table-land rises continuously to 
Flagstaff and beyond and also northwestward to the edge of the 
Grand Canyon. The greater part of its surface consists of bare lime- 
stone (the Kaibab), which dips at a low but nearly uniform angle to 
the east and southeast. At Winslow this limestone is some distance 
beneath the surface, under the red sandstones of the Moencopie for- 
mation, but as it rises to the west at a somewhat more rapid rate 
than the ascent of the railway it finally reaches the surface. It first 
appears at a point a short distance beyond Dennison siding (see sheet 
18, p. 120), but for several miles, to and beyond Sunshine siding, 
numerous outlying masses of the basal red sandstone of the Moen- 
copie remain on it. Just south of Sunshine this sandstone has been 
quarried to a considerable extent for building stone. 
About 10 miles south of Sunshine is Crater Mound, long known as 
Coon Butte and for a while as Meteorite Mountain, perhaps the most 
mysterious geologic feature in the West. Viewed 
from the railway, it appears as a low ridge (see Pl. 
XXV, A), but on near approach this ridge is found 
to be circular and to inclose a great hole 4,000 feet 
in diameter and 600 feet deep. (See Pl. XXV, C.) The encircling 
ridge is from 100 to 150 feet high and consists of loose fragments 
Sunshine. 
Elevation 5,341 feet. 
Kansas City 1,227 miles. 
‘The cause of this great hole in the 
ground has not been ascertained. Sev- 
eral geologists believe that it was made by 
the impact of a great meteor, a view sug- 
masses of meteoric iron in the vicinity, 
as well as elsewhere in the surrounding 
to be buried in the hole failed to obtain 
any evidences of itsexistence. Many test 
0rl and a shaft were sunk 200 feet 
into the detritus in the floor of the hole, 
and a 1,020-foot hole found that the un- 
erlying es are not disturbed. 
- _ Moreover, a detailed survey with a mag- 
netic needle, hung to swing vertically, 
failed to show any evidence of the pres- 
ence of a body of metallic iron. 
Another suggestion is that the hole is 
as f+ £ i 
due toan e 
the broken sandstone and limestone con- 
j +h Ce 2 : 1¢ :e 
stitntine + 
ig Zz tne up- 
turned edges of the strata, which doubtless 
would bend upward somewhat before 
they broke. The large amount of fine 
sand produced would result from the 
violence of the explosion of steam con- 
ined in the interstices of the sandstone. 
Such an explosion might not greatly dis- 
wh, th < | heute a. = : Ree -£ +h, 
tm 
