hayden.] CURIOUSLY-ERODED SANDSTONES. 43 



it, since my first examination of it, nearly twenty years ago, yet more 

 direct proof must be brought to bear before long in some portion of our 

 continent. These red sandstones have always attracted much attention 

 wherever noticed, on account of their peculiar color, but nowhere have I 

 ever observed them performing such a conspicuous part in giving form 

 to the scenery of the country, as along the eastern base of the Rocky 

 Mountains in Colorado. This feature is more marked from a point about 

 fifty miles north of Denver to Colorado Springs, than in any other por- 

 tion of the continent. Along this belt the sandstones are more compact, 

 with every variety of red, from a pale dull tint to a deep purple color. 

 There is also every variety of texture, from a rather coarse conglomerate 

 to a fine sandstone. It varies much in thickness, ranging from 400 to 

 2,000 feet. Its greatest thickness south of Platte Canon is in Pleasant 

 Park and in the "Garden of the Gods," at Manitou. At Pleasant Park, 

 according to Dr. Peale, the aggregate thickness of the Eed Beds is about 

 2,000 feet. This series of beds is well shown in the pictorial section. 

 These sandstones have been elevated at various angles varying from 20° 

 to a vertical position. In the vicinity of the Manitou Springs, in what 

 is usually called the " Garden of the Gods," the same variation is seen, 

 but in many instances the beds are very massive, thick, and stand in a 

 nearly vertical position. In Plates VIII and IX we can see the massive 

 sandstones, which have been weathered into the most fantastic shapes, 

 standing up in immense walls or columns 50 to 250 feet in height. 

 Plate VIII represents what is called the gate or entrance to the "Garden 

 of the Gods." In the foreground is seen the massive wall of red sand- 

 stone rising on either side of the opening to the height of 100 to 150 

 feet. The wall was originally continuous, but has been worn through by 

 erosion. Whatever may have been the agents which in times past 

 have wrought out all these remarkable forms, it is plain that they have 

 acted in former times with far more intensity than at present. In the 

 background, through the opening, may be seen the snow-capped sum- 

 mits of Pike's Peak, rising to a height of 14,147 feet above sea-level. 

 Plate IX gives an example of what might be called a magnificent mono- 

 lith. It is an immense column of bright-red Triassic (?) sandstone rising 

 to a height of 250 feet above the general level, a portion of a massive 

 stratum elevated to a vertical position, and the contiguous portions 

 eroded away. Figure 1, plate IX, illustrates the singular columns which 

 stand at the entrance of the "Little Garden of the Gods," or, as it is now 

 called, " Glen Eyerie." On account of the peculiar forms which these red 

 sandstones have received from the eroding agents of nature, this locality 

 will always remain one of the most celebrated in Colorado. 



The more careful study of the relations of these sandstones to the 

 underlying rocks, has thrown much light on the physical history of 

 this region. My own observations, farther to the northward, led me to 

 the belief that the great uplift of the mountain-ranges, though imper- 

 ceptibly slow, was an unit in its action; or, in other words, that the 

 changes in the position of all the groups were brought about by the 

 same cause and at the same time. There could not be a strict conform- 

 ity in the sedimentary groups, inasmuch as entire groups are wanting, 

 and in some cases only fragments of others are remaining. But I have 

 hitherto supposed that the elevation of all the sedimentary strata along 

 the base of the mountains was a comparatively modern event. We now 

 have the evidence, from the texture of these red beds and their position 

 on the underlying granitic rocks, that the Front Range, during the 

 supposed Triassic period, formed a vast shore-line, and that the sedi- 

 ments of the Red Beds were deposited on the base against the sides of 



