GEOLOGICAL SURVEY OF THE TERRITORIES. 143 



if they liad been partially changed by heat. There is every variety of 

 texture, mostly silicious, but some layers appear to be an impure lime- 

 stone. 



For a space of about ten miles from north to south, and an average 

 width of five miles from east to west, about Colorado City, all the 

 unchanged rocks are displayed in a unique and remarkably clear man- 

 ner. The ridges of upheaval are spread out over an unusually wide 

 space. Here every formation known in this region is distinctly revealed 

 to the scrutiny of the geologist. 



Beginning in the plain country we have the sands and sandstones 

 of the Monument Creek group in a perfectly horizontal position, and 

 separated from the older rocks by a valley about half a mile wide. It is 

 through this valley, which runs neaily north and south, that the road 

 passes. The Monument ('reek group is seen on the east in the form of. 

 a rounded grassy range of hills; while on the west side the cretaceous 

 formations are exposed in the form of upheaved ridges. I have no 

 doubt but that this intervening valley is underlaid by lignite tertiary 

 beds, for as we enter it from Monument Creek valley we have an expo- 

 sure of the sandstones of this group for a little distance, revealed by the 

 stripping off' of the Monument Creek sands by erosion. They very soon 

 pass beneath the more recent deposits. On the west side of the road, 

 near Camp Creek, which flows through what is called the second "Gar- 

 den of the Gods," we find the chalky shales of No. 3 with Inoceramus and 

 Ostrea congesta in great abundance. All the cretaceous rocks, including 

 the massi'S'e sandstones of No. 1, are finely displayed in this region, and 

 No. 1 forms a most picturesque and nearly vertical wall for six to ten 

 miles, as it were inclosing the "Garden of the Gods." There is one 

 peculiar feature presented by these nearly perpendicular walls of sand- 

 stone, and that is, two quite distinct lines of cleavage, but not quite as 

 regular or as well defined as in the gneissoid rocks of the mining regions. 

 These lines cross each other, one set with a direction northwest and 

 southeast, and the other southwest and northeast. 



The rocks included in this wall-like ridge are layers of fine black shale, 

 fine sandstone with bits of vegetable matter, and a thin seam of earthy lig- 

 nite. Then come beds of whitish sandstones, with thin layers of limestone 

 made up of indistinct fragments of fossil shells, with bed of snowy 

 gypsum ; then a series of whitish, yellow, and brick-red sandstones, with 

 intervals of loose, laminated sands, which form a kind of grassy valleys. 

 In passing up the Fountain Creek valley we cross the upheaved edges 

 of twenty or thirty of these fragmentary ridges, all inclining at various 

 angles, from ten degrees to sixty degrees. It is to the peculiar weath- 

 ering of these variegated upturned ridges of sandstone that the wonder- 

 fully unique scenery of the "Garden of the Gods" is due. In some 

 localities some of these beds seem to pass over beyond verticality 3^ 

 to 5°. The composition of these sandstones is mostly fine sand, but 

 often it is an aggregate of minute particles of quartz, with some small, 

 rounded pebbles. All the beds exhibit the indications of ripple 

 marks, irregular lines of deposition, and in most, the water-worn pebbles 

 are small, but sometimes they are from six to ten inches in diameter. 

 The upper portions of the variegated beds are a light brick red, with 

 spots and irregular layers of whitish sandstone. 



As we pass to older beds this red color deepens until it becomes a dull 

 purple hue. There are in all these sandstones a great many irregular 

 seams of gypsum. Everywhere among these curious projecting ridges 

 of sandstone are beautiful gTassy intervals. To show the irregularity 

 of the dij) of these rocks, the ridges that give the most marked features 



