34 GEOLOGICAL SURVEY OF THE TEERITOEIES. 



the sediments become finer and finer, until the whole group contains a 

 very small portion of the coarse aggregate. It would appear that the 

 sediments of these beds were derived from the mass of metamorphic 

 rocks in the vicinity after they had risen to or near their present eleva- 

 tion. 



" The variety -of coloring is not so well shown in the Monument Creek 

 group as in the Triassic sandstones of Pleasant Park. The metallic 

 oxides have given a good share of beauty to the former, enhancing the 

 attractions of these singular freaks of nature. Pleasant Park is located 

 among the uplifted ridges of the Triassic, Jurassic, and Cretaceous 

 groups, and the peculiar forms that are worn out of the variegated sand- 

 stones are not even as wonderful as the variety of rich, beautiful shades of 

 coloring. Far north of this point, and south, in the Garden of the Gods, 

 and many other localities, the red sandstones are displayed on a grand 

 scale, but nowhere else are the rich colors, consisting of all shades of red, 

 pink, yellow, gray, and white so well shown. The tints were unusually 

 vivid, and contrasted so as to produce fine effects. This whole region 

 would be a paradise for an artist. The unique forms which have been 

 carved by the elements out of the sandstones are most conspicuous. 

 Near Koontz ranch is a group of weathered masses of sandstone that 

 look like hay-stacks. These rocks are stratified, with the layers in- 

 clining from the mountains to the east 10°. 



The next point of interest is the district around the east base of Pike's 

 Peak, in the valley of the Fountain Creek. This little stream rises up 

 in the mountain-range of which Pike's Peak forms a part, flows south- 

 east, cutting through the upheaved Sedimentary ridges, after emerg- 

 ing from the mountains, nearly at right angles. The ridges on the 

 north side of the creek trend a little east of south, but immediately 

 on the south side flex toward the mountains at a sharp angle, 

 trending west of south and very soon apparently striking the granite 

 mountain-sides and are thus cut short off. The entire group thus forms 

 an obtuse angle, and Fountain Creek has carved out its channel pretty 

 directly through the angle. The channel therefore affords a most excel- 

 lent opportunity for the study of the formations in their consecutive 

 relations. But the question arises, how is it that they are developed to 

 such an enormous thickness so suddenly ? Has there been an increased 

 deposition of sediments at this particular locality? I have already 

 alluded to the absence of all rocks below the supposed Triassic or red 

 beds along the flanks of the mountains from the Union Pacific Eailroad 

 to Colorado Springs. We may, then, ask why it is that there should be 

 exposed here so suddenly, not only an unusual development of the Tri- 

 assic or red group, but below it 1,000 to 1,500 feet of reddish and gray 

 sandstone-quartzites with intercalated beds of clay of varied thickness, 

 probably Carboniferous, ahd below this a group of limestones more or 

 less impure resting unconformably on the Metamorphic rocks contain- 

 ing well-defined Silurian fossils. There cannot be less than 4,000 feet 

 of sedimentary beds below the Cretaceous No. 1 exposed in the valley 

 of Fountain Creek, while for a distance of one hundred and fifty miles 

 north of this point the aggregate thickness of the Triassic and Jurassic 

 groups is probably not over 1,500 feet at any locality. The little streams 

 that flow down from the mountain- sides have cut deep canons through the 

 Silurian beds as they lie high upon the granite foot-hills, and deep into the 

 granites also; so that the opportunity. for special studies is as complete 

 as could be desired. Most excellent sections can be obtained in Williams's 

 Caiion, Chiann Cafion, and in a dozen gorges extending along the mount- 

 ains for about five miles. My time was so limited that, even with 



