DENVER & EIO GRAlsTDE WESTERN" ROUTE. 



37 



on end and then were partly removed by the dissolving action of the 

 atmosphere. This is a slow process, but it is always in operation, 

 and each day a few grains of sand are loosened and carried away. 

 Under this constant attack new and picturesque forms are being 

 produced and the old pinnacles and towers are being worn away. 

 All these interesting monuments of the activity of weathering proc- 

 esses will at some time be worn down to the level of the plain, but 

 that time will be so far in the future that the loss of the monuments 

 need not give much concern to the present generation. 



The great ledges that give to the Garden of the Gods its pic- 

 turesqueness extend to the north and are again strikingly exposed in 

 Glen Eyrie, which for a long time was the chosen home of Gen, 

 Palmer. Plate XVII, C (p. 33) , shows one of the more striking rocks 

 in this well-known glen.^^ 



" The rocks in and about the Garden 

 of the Gods and Glen Eyrie are more 

 fully described by Prof. George I. Fin- 

 lay as follows : 



Few regions in the United States 

 offer so much to the traveler and to 

 the student of rocks as the country 

 about Colorado Springs. The Rocky 

 Mountains here meet the Great Plains 

 with a bold front. At some places, 

 owing to faults or breaks in the beds 

 of rock, the old, strong granite of the 

 mountains stands in direct contact with 

 the young, weak rocks of the plains; 



under the waters of shallow seas that 

 from time to time invaded this part of 

 the continent. Such seas were exten- 

 sions of the Gulf of Mexico or were 

 connected with the oceans that sur- 

 rounded the continent. At one time, 

 in the Cretaceous period, the Gulf of 

 Mexico and the Arctic Ocean were con- 

 nected by a sea that extended across 

 North America. The continent was 

 then reduced to a number of islands, 

 many of which were nearly continental 

 in size. The shallow water between 

 them became the settling ground for 



SOOOfeet above sea level 



Figure 10. — Section through Garden of the Gods. The spires and walls of the gateway 

 are carved in the upstanding block of sandstone, and this block is separated from the 

 rocks on both sides by faults. For explanation of letters see Plate XXII. 



at others, as at Manitou and in the 

 Garden of the Gods, the sedimentary 

 beds are upturned in a narrow belt 

 that offers the traveler an unusual op- 

 portunity to examine and study them. 

 The layers of rock that compose the 

 foothills and plains are like books on 

 a shelf which have fallen over toward 

 one end, so that most of them lie at 

 low angles, although a few are nearly 

 vertical. (See fig. 10.) 



These rocks lie in distinct layers 

 because most of them were laid down 

 80697°— 22 4 



the sand, mud, and gravel which the 

 streams brought down from these great 

 islands. Along the shores the waves 

 were cutting away the land and re- 

 ducing it to mud and sand, and strong 

 currents were carrying these materials 

 widely over the sea floor. After this 

 condition had prevailed for a long 

 time the continent was uplifted and 

 was restored to something like its old 

 outline. During these changes sand 

 was consolidated into sandstone, mud 

 into shale, and gravel into conglomer- 



