OKIGIX AND USE OF NATURAL GAS AT MANITOU. 15 



It may be of interest to discuss the origin of this natural 

 gas, and then to describe the means by which it is made to 

 again impregnate the mineral water taken from the springs. 



In seeking to trace the sources of this abundant supply 

 of natural gas, it will be helpful to consider certain of the 

 prominent geological and topographical features of the dis- 

 trict in which the springs occur. Manitou lies in a mountain 

 gulch or valley at the base of Pike's Peak, and just at the 

 entrance to the Ute Pass. In fact the valley is but the 

 eroded and widened outlet of the Pass — itself a narrow water- 

 carved channel through which the drainage of an area some 

 seventy-five to one hundred square miles in extent finds its 

 way to the eastern base of the mountains. The stream which 

 drains this tract obtained the name '"Fontaine qui Bouille" 

 from the bubbling or boiling springs on its banks at Manitou. 

 On the south and west of the picturesque little city rise the 

 granite slopes of Pike's Peak, while to the north are piled up 

 the huge masses of stratified rock which flank the other side 

 of the valley. Thus Manitou lies at the junction of the old 

 archaean rocks, with more recent sedimentary formations. 

 Just west of Manitou, however, the limestone beds are found 

 for a short distance on both sides of the Ute Pass. The 

 archaean rocks at Manitou consist almost exclusively of 

 highly feldspathic red granite which disintegrates very readily 

 under atmospheric agencies. Further up the Pass are found 

 patches of syenitic gray granites containing soda feldspars. 

 There are no igneus rocks in this neighborhood save a few 

 narrow dikes, and on the south slope of Pike's Peak, about 

 two miles from the summit, one exposure of phonolite, but 

 not many miles distant at Cripple Creek, large areas of erup- 

 tive rocks are exposed to view. A number of rock slips or 

 faults in the granite are to be seen in the neighborhood of 

 the Peak. 



At Manitou and to the northwest, only the paleozoic 

 series of sedimentary beds are exposed, e. r/. silurian, carbon- 

 iferous and juratriasic, and these are mainly represented by 

 limestones and sandstones. The granite slopes of the Front 

 Range, which extend in a generally north and south line, are 



