124 GUIDEBOOK OF THE WESTERN UNITED STATES. 
Half a mile beyond milepost 315, at the crossing of a small creek 
which enters the river from the ibis: the base of brilliant light- 
red sandstone is exposed. This sandstone is Triassic in age and is 
much more showy in color than any other rock which the traveler has 
seen since he left Canon City. On account of its striking color 
attempts have been made to utilize it as building stone, but gener- 
ally it is so easily affected by the weather that in a few years the 
corners are rounded off and even great holes are etched in the solid 
blocks. Where first seen these beds dip about 45° W., but the dip 
flattens in a short distance to about 25°.%* Beyond wide poet 316 the 
top of the bright-red beds may be seen on both sides of the river. 
On the right they extend down the hillside in a great curve, but on 
the left eid run along the face of the bluff with only a slight dip 
downstrea 
The sos that overlie the bright-red sandstone are variegated 
in color but are predominantly green and maroon. ree make up 
w. E. 
— 
== 
SS 
—- ss i= = . sak 
7,000 == ~ RAILROAD = ime greiner =e 
fare a = = 
“eos formation === = =~ 
Ficure 32.—Sketch section across the syncline at Wolcott on a line from east to west. 
what is called the Gunnison formation, so named from its outcrop 
in the valley of Gunnison River. The upper part of this forma- 
tion is without doubt the same as the Morrison formation on the 
east side of the mountains, but its lower part probably includes 
rocks that are not found on that side. The Gunnison formation 
here contains much soft shale and clay but includes also some beds 
of resistant sandstone. At this place the formation has been so 
much crushed that its thickness can not be estimated, but at other 
outcrops in this vicinity, where it is undisturbed, it is about 220 
feet thick. The discovery of the remains of some very wonderful 
“The peculiarities and irregulari- ; stand on edge, as shown by the ac- 
ties of the dips in this part of the | companying diagram, but they flatten 
valley can be best understood by refer- | rapidly as they pass below water level, 
ence to the map on page 134. This map | and as seen farther on they lie nearly 
shows that the river here cuts di- | flat along its axis. 
agonally across the rim of a sag or The meaning of the dips is well illus 
basin in the rocks (not a surface ba- | trated in the accompanying sketch (fig- 
sin), the lowest part or axis of which | 32), which shows the rocks as they 
is crossed by the railroad a mile or | would appear in a deep trench cut vel- 
so farther north toward Wolcott. On | tically from east to west through the 
the eastern rim of this basin the rocks | fold, 
