1922] EDWARDS, GEOLOGICAL WORK AT GRAND CANYON 93 



fully a thousand people lived at one time in these cliff dwellings which 

 are scattered along the entire three miles of the canyon. 



From Flagstaff' our journey led on to Williams, and from there, 

 by a branch line of the railway, to the Grand Canyon, sixty-four miles 

 to the north. The railroad between Williams and the Grand Canyon, 

 is built entirely upon the flat, but gently rising surface of the Coconino 

 Plateau. This plateau is underlain by the Kaibab limestone, and it is 

 through this great plateau that the Colorado river has carved its way 

 in the series of canyons, which together form the Grand Canyon. From 

 the end of the branch of the railroad, it is but a few steps to the brink 

 of the canyon itself, which is cut through the level rocks of the plateau 

 and is invisible until one is at its very brink. From any point upon the 

 edge ,of the canyon the panorama is most impressive. It is probably 

 of equal, if not greater, interest than that to be seen at any other place 

 in the world. 



Directly in front of the hotel, the river has excavated a channel 

 forty- four hundred feet in depth, and about ten miles in width. The 

 river is about twice as far from the north rim of this great gorge as it 

 is from the south rim, and is almost completely concealed by the walls 

 of the Granite Gorge, a deep and narrow canyon cut into the bottom 

 of the main excavation. The walls are made up of the various layers 

 of rock which form the high plateaus on both sides of the canyon. 

 They are red, light green, white and gray in color, and in horizontal 

 layers which can be traced along the walls of the canyon as far as the 

 eye can reach. These layers consist of sandstone, limestone and shale 

 which, by their structure and by the fossils they contain, show that 

 they were formed beneath the waters of the sea. Since they now occur 

 nearly a mile above that level, it follows that this region has been ele- 

 vated at least to that extent and without any appreciable deforma- 

 tion of the layers, as they still appear as horizontal and level as if they 

 were in their original positions. Some study, however, soon shows 

 that the northern rim of the canyon is considerably higher than the 

 southern. This is caused by the slope of these beds, the same lime- 

 stone forming the surface of the plateau north of the canyon as south 

 of it. 



Many buttes, mesas, temples and other imitative forms are seen on 

 the north side of the river between the Granite Gorge and the rim of 

 the canyon. These make a most interesting series of rock forms, which, 

 for the most part, simulate architectural designs on an enormous scale. 

 These buttes and mesas are the features which, above others, distin- 



