DENVER & RIO GRANDE WESTERN ROUTE. 



39 



made a trip to the source of the Mississippi when he was directed to 

 explore what was then known as the " Southwest." He and his 

 party left Missouri in July, 1806, and went across the country to 

 the Arkansas and up that valley to the site of Pueblo. At the mouth 



than a thousand feet of coarse mate- 

 rial. The Fountain formation is simi- 

 lar to the Dawson arkose, and much of 

 it was no doubt similarly deposited. 

 The Lykins formation is made up of 

 beds which were laid down in land- 

 locked bodies of water in a region 

 that had an arid climate. The Lara- 

 mie formation is made up of beds of 

 sandstone and shale between which 

 there are layers of coal that repre- 

 sent accumulations of vegetal matter 

 in swamps. When a tree dies in the 

 forest it quickly decays, but when it 

 falls into a pond of water, as in a 

 swamp, the water protects it in a 

 great measure from decay, so that its 

 carbon is stored up and accumulates 

 as coal. 



Colorado Springs is built on the 

 nearly horizontal Pierre shale. The 

 road from Colorado Springs to Man- 

 itou leaves this shale just west of 

 Colorado City and in the succeeding 

 3 miles crosses the steeply upturned 

 beds of the Cretaceous formations. 

 Beyond Quarry Spur it passes over 

 the Fountain beds, which underlie 

 Manitou. These relations will be un- 

 derstood from a study of the map 

 shown in Plate XXII and the cross 

 section forming figure 10. 



On leaving Manitou a walk of less 

 than a mile up Ute Pass as far as 

 Rainbow Falls takes one past the 

 sedimentary rocks into the granite. 

 On either hand, resting on the granite, 

 are the lowest white layers of the 

 Sawatch sandstone, of Cambrian age, 

 the oldest sedimentarj' rock in this 

 region. Tlie contact between the 

 granite and tlie sandstone is every- 

 where so remarkably even as to indi- 

 cate clearly that before the sand 

 which formed the sandstone was de- 

 posited the granite had been worn 

 down to a smooth surface or a nearly 

 perfect plain. About 50 feet above 



the granite the dove-colored Manitou 

 limestone (Ordovlcian), over 200 feet 

 thick, succeeds the sandstone and 

 forms the bulk of the ridge between 

 Ute Pass and Williams Canyon. In 

 Williaftis Canyon (PI. XXIII) the 

 walls are composed of the same two 

 formations, overlying the granite. 



The Cave of the Winds, in the Man- 

 itou limestone, compares favorably 

 with the Mammoth Cave of Kentucky 

 and the Luray Caverns of Virginia, 

 though it is by no means so large. 

 The limestone in which the cave has 

 been excavated was honeycombed by 

 the solvent action of rain water, 

 which .sank into it along cracks and 

 passed through it in small streams. 

 Later the streams left the caverns 

 which they had made, and the dis- 

 solved lime carbonate in the water 

 that dripped from the cracks in the 

 roofs of the cavern produced icicle- 

 shaped forms known as stalactites. 

 Water dropping on the floors of the 

 caves similarly built up stalagmites. 

 Queens Canyon, 3 miles north of Col- 

 orado City, is in the same formation. 



East of Manitou and north of the 

 railroad track there are fine exposures 

 of the Fountain formation, which 

 stretches over to the Garden of the 

 Gods. The red rock series — made up 

 of the Fountain formation, the Lyons 

 sandstone, and the Lykins formation — 

 is about 5,000 feet thick. Near 

 IManitou the Fountain beds dip 11° 

 E. In the Garden of the Gods they 

 were tilted until they stand vertical, 

 and in the intervening ground they 

 stand at intermediate angles. (See 

 fig. 10.) Interesting erosion forms 

 may be seen in the Fountain forma- 

 tion in Mushroom Park and just west 

 of the great masses of Lyons sand- 

 stone in the Garden of the Gods. 

 Some of these forms rise 200 or 250 

 feet above the adjacent ground. 



