28 COLORADO COLLEGE STUDIES. 



the Springs and hence tlie springs do not become roily, and 

 the temperature of the water remains quite constant, retain- 

 ing still enough heat to be designated as ''thermal'" in the 

 U. S. Government Reports. 



The coincidence between the diminution of the salts and 

 that of the water and gas during the coldest winter mouths, 

 probably arises in this manner. The feeders of this fissure- 

 flow are in large part the seams and cleavage cracks in the 

 rocks adjacent to the main fault or its branches, and they in 

 turn derive their supply from the surface waters which per- 

 colate downward. In the very cold weather the seepage 

 waters — as is well known in mining regions at high eleva- 

 tions — are greatly diminished, being held in check by frost, 

 so that the supply is lessened in the main fault. In like 

 manner the slopes of the Ute Pass and the neighboring hills 

 which may be supposed to furnish the seepage waters of the 

 sedimentary beds at Manitou are restraining (by frost) their 

 quota of the supply for the springs. Especially would this 

 be true if, as appears probable, the more elevated and com- 

 paratiA^ely shaded south side of the Pass furnishes the bulk 

 of the seepage waters which make their way to the springs. 

 Under these conditions the temperature of the springs would 

 not generally gi-eatly vary in summer or winter, since the 

 colder surface waters of the latter season which mingle with 

 the decreased fissure- waters would also be much diminished 

 in volume. With the decrease in water would come a de- 

 crease in salts, and so also of the gas jiroduced by the re- 

 actions previously outlined. 



The salts coming from the assumed fissure beneath the 

 limestones naturally tend to follow the seams and bedding 

 planes of the stratified rocks and thus to make their way 

 down the easterly slopes without coming to the surface. The 

 resistance to this flow resulting from friction and perhaps 

 from sharp folds and faults east of Manitou, causes the waters 

 to force an exit through the broken and folded strata at the 

 western side of the city. The two small flexes of surface rock 

 before mentioned apj)ear to give in their crevices the oppor- 

 tunity for a final escape to the surface of the water and gas. 



