38 



GUIDEBOOK OF THE WESTERN UNITED STATES. 



PIKES PEAK. 



Manitou is the place from which the start is made on the Cogwheel 

 Road for the ascent of Pikes Peak. Pikes Peak, the highest moun- 

 tain in this part of the system (14,109 feet), was named for its dis- 

 coverer, Lieut. Zebulon M. Pike, who was commissioned by Presi- 

 dent Jefferson to explore certain parts of the western country ac- 

 quired from France by the treaty of Paris, signed April 30, 1803, 

 and generally known as the Louisiana Purchase. Pike had already 



ate, all being cemented and welded to- 

 gether by the great weight of the lay- 

 ers above. In the sea limy shells ac- 

 cumulated in great beds and were in 

 large part ground up by the waves and 

 reduced to fine particles, which were 

 cemented together by a part of their 

 lime carbonate into beds of limestones. 

 These several kinds of rock — shale, 

 sandstone, conglomerate, and lime- 

 stone — are the sedimentary beds which 

 are so well represented near Colorado 

 Springs, where their total thickness is 

 over 10,000 feet. These beds of rock 

 were not originally vertical or inclined 

 but lay horizontal, and it was the up- 

 lift of the mountains, which occurred 

 long after they had been formed, that 

 disturbed them. Their edges are now 

 exposed all the way from Manitou to 

 Austin Bluff, east of Pikeview. The 

 oldest of these beds are those which 

 lie upon the granite of the mountains ; 

 the youngest are those which are ex- 

 . posed in Austin Bluff and beyond; and 

 the beds of intermediate age are those 

 in the Garden of the Gods. 



The formations into which the sedi- 

 mentary rocks of the Colorado Springs 

 region are grouped by geologists and 

 the names of the geologic periods in 

 which they belong, as determined by 

 the study of their fossils, are shown 

 on sheet 2 (opposite p. 84) and in the 

 general section on page ii. The term 

 formation is generally applied to a 

 distinctive bed or a series of distinc- 

 tive beds of rock, such as sandstone, 

 shale, or limestone, that were formed 

 continuously or in close succession dur- 

 ing a certain period of geologic time, 

 or to a group of beds that are of 

 about the same geologic age. It 



is thus frequently applied to such 

 an assemblage of beds as may be 

 grouped together as a unit for con- 

 venience in mapping. The deposits 

 made in a single geologic epoch or 

 period are usually represented by sev- 

 eral formations. In this region the 

 Upper Cretaceous epoch, for instance, 

 is represented by eight formations, 

 though other periods are each repre- 

 sented by only one formation. Be- 

 tween the Manitou limestone and the 

 shale at the base of the Fountain for- 

 mation there are no representatives 

 of the rocks that were formed else- 

 where during the Silurian and De- 

 vonian periods. Nor is there any rock 

 to represent the earliest division of 

 the Carboniferous period. The ab- 

 sence of tliese beds means either that 

 during these long periods of time the 

 Colorado Springs region was dry land, 

 upon which no material was being de- 

 posited, or that the rocks then de- 

 posited there were later worn away. 

 Between the Lykins and the Morrison 

 formations no representative is found 

 of the Triassic period, whose rocks 

 constitute another of the geologic sys- 

 tems. 



Not all the sedimentary rocks of the 

 Colorado Springs region were laid 

 down on the sea floor. The Dawson 

 arkose, for instance, at the top of the 

 column, was spread out on the land 

 by the many eastward-flowing streams, 

 which brought quantities of disinte- 

 grated granite and gravel down from 

 high lands on the west. As these 

 streams shifted from side to side over 

 the country they spread gravel some- 

 what evenly over the slope until they 

 had thus deposited considerably more 



