THE SANTA FE ROUTE. ET 
were forced to abandon them owing to the hostility of tribes living 
farther east. 
Two miles beyond Cosnino the train approaches a large cinder 
cone which extends for about a mile along the north side of the track, 
and halfway between mileposts 336 and 337 there are cuts exposing 
some features of the cinder deposits constituting this cone. Most of 
the material is fine grained but there are many included masses 
consisting of cinder agglomerated together and numerous bombs. 
One of the most notable examples of a recent cinder cone is Sunset 
Peak, which is visible 10 miles to the north from the vicinity of 
milepost 337. This cone is 300 feet high and has steep slopes of loose 
cinders, part of which are of a bright-red color, giving the cone the 
appearance of being illumined by the setting sun. The crater at 
the top is 80 feet deep and 
200 feet in diameter, but 
the original orifice under 
this depression is covered 
by the loose material 
sliding down the steep 
slopes. 
Halfway between mile- 
posts 338 and 339 is ared FiguRE 25.—Section of Elden Mountain, east of rio noe ay 
cinder cone 200 feet high, se, uma e dae sandstone (Coconino); c, red me 
half a mile north of the — (Supai); d, limestone (Redwall); ¢, igneous rock. (After H. H. 
railway, with a small 
tongue of lava extending from its base southward to a point a short 
distance east of milepost 339. : 
At Cliffs the train runs near the south edge of Elden Mountain, 
& prominent mass of dark-colored dacite of the second period of vol- 
canic activity. The lava is in heavy beds presenting 
rae an arched appearance, suggesting strongly that the 
Elevation 6,829 feet. in thick viscous layers which 
Mikdnarien tae tee, lava was poured out in thic us lay 
were finally bent upward by the pushing of some 
central force at or toward the end of the period of eruption. That 
this range has been considerably upthrust is further indicated by 
the presence of some large uplifted masses of the sedimentary rocks 
of the plateau along its east side. In this uplift are exposed the 
Redwall limestone, the red sandstone of the Supai formation, the 
Coconino sandstone, and the Kaibab limestone, all dipping steeply 
eastward with the relations shown in figure 25. : 
alf a mile south of Cliffs there are some remarkable sink holes in 
the bottom of the valley, known as the Bottomless Pits (PI. XXVIII). 
They form the entrance to a cavern in the Kaibab limestone made 
by the solvent action of water on the limestone in its passage under- 
ground through joints and fissures to outlets in the depths of Walnut 
Canyon, a few miles south. 
