i6 



influences, or because of their position with regard to the 

 currents. They seem to be an aggregation of quartz grains 

 and pebbles loosely held together in a nearly circular column, 

 which tapers from the thick base towards the top. This shaft 

 is surmounted by a cap of rust-colored sandstone, which owes 

 its greater size to the oxide of iron that forms a cement, bind- 

 ing the grains together. This sandstone being on that ac- 

 count a much harder compound than the layers below it has 

 resisted erosion to a greater degree. The smaller monuments 

 here described vary in height from 10 to 20 feet. There 

 remain, however, some other forms which must not be 

 omitted in this description, and those are the castellated 

 forms of the larger table buttes or " mesas." These mass- 

 ive objects are from 100 to 250 feet in height, and are some- 

 times capped with a layer of purple porphyritic basalt. 

 They rise from the beautiful green meadows, and their almost 

 perpendicular sides give them an appearance which is par- 

 ticularly impressive just at sunset. 



There seems to be but little doubt that this line of up- 

 turned strata exists throughout the whole length of the Front 

 Range, though hidden in some parts of its length. It is 

 separated from the Front Range by a valley, the portion of 

 which that lies fifty miles to the north of Colorado Springs 

 is the most picturesque, and will always retain its celebrity, 

 on account of the striking forms of erosion just described. 



Pike's Peak is situated just west from Manitou and the 

 Garden of the gods. It is a mountain composed of fine- 

 grained reddish granite, which is believed to be metamorphic. 

 The appearance of some fragments of sedimentary rock at its 

 foot gives rise to the supposition that in Silurian times there 

 was a bay at its base, this being the point farthest west at 

 which these rocks are found in this range. It is also the 

 point where the summit of the range approaches nearest to 

 the plains ; the upheaving force seems here to have been ex- 

 pended in elevating the older layers above the sea, making 

 them form part of the shore-line and driving the sea more to 

 the east ; whereas to the north of this the force being more 

 distributed caused a more general elevation. The same is 

 supposed to be true with regard to the Mt. Evans group at 



