46 SUEVEY OF COLORADO AND NEW MEXICO. 



lias formed a basin six or eiglit feet across, from the center of which 

 boils up a most violent current, so that one would suppose there was 

 water enough to make a good-sized trout brook, and yet not more than 

 five or six gallons a minute issue from it. A small stream about four 

 inches wide, and an inch deep, passes oif into the creek. About this 

 , si)ring, also, there is a large deposit, which is rounded off on the side 

 toward the creek by the overflow of the water from the spring. 



On the opposite side of the creek, not more than twenty feet from it, . 

 and located about ten feet above it, is a third small spring. The water is 

 stronger than that of the others and is used principally for drinking 

 purposes. The cavity in this deijosit is about twelve inches in diameter 

 and the water twelve inches deep, and the bubbles rise continually and 

 energetically, but not more than half a gallon of water a minute passes 

 off. There is now a constant deposition of a whitish substance from 

 the sjDring, and it extends to the margin of the creek. Between the sec- 

 ond and third springs are two massive red felspathic granite boulders, 

 a coarse aggregate of feldspar, quartz, and some black mica. Ou e of these 

 boulders, which lies on the left side of the creek, must be at least twenty- 

 five feet in diameter, and is partially rounded by atmospheric influences. 

 The other is perhaps six feet in diameter and lies in the middle of the 

 stream, and between the two, in a space of three feet, the greater part 

 of the water of the brook rushes down with considerable force. 



The fourth spring is perhaps fifty feet above the second, on the right 

 side of the creek, and within four feet of the water's edge. There is no 

 sediment deposited around it, and, although the water bubbles up some- 

 what, it is rather chalybeate than otherATise. The taste is scarcely 

 perceptible, and but little notice is taken of it by tourists. 



The basin of the second spring is about four feet deep and is used for 

 bathing. The first three S]3rings are strongly impregnated with car- 

 bonic acid gas and are the true springs. 



These springs must necessarily have their origin in the metamorphic 

 rocks, although the waters may pass up through a considerable thick- 

 ness of the older sedimentary beds. On both sides of Tountain Creek 

 there is a considerable thickness of the carboniferous beds, but the creek 

 seems to run through a sort of monoclinal rift, though at the falls above, 

 the stream cuts through the ridges nearly at right angles. At any rate, 

 there cannot be a very great thickness of the unchanged rocks below 

 the surface at the springs. 



As these springs must at some period become a celebrated and ]wpu- 

 lar resort for invalids from all parts of the world, I will add an analysis 

 of a fragment of the incrustation mentioned above, as given in Fremont's 

 report, page 117. 



Carbonate of lime 92. 25 



Carbonate of magnesia 1. 21 



Sulphate of lime, chloride of calcium, chloride of magnesia .23 



Silica 1. 50 



Vegetable matter .20 



Moisture and loss 4. 61 



100. 00 



"At 11 o'clock, when the temperature of the air was 73°, that of the 

 water in this was 60^.5 ; and that of the uj)per spring, which issued from 

 the flat rocks more exposed to the sun, was 69°. At sunset, when the 

 temperature of the air was 66°, that of the lower springs was 58°, and 

 that of the upper 61°." — Fe:^mont. 



