A short distance above the spring, and near the foot of the same spur, is a very remarkable, yellow-colored rock, soft and friable, consisting principally of carbonate of lime and oxide of iron, of regular structure, which is probably a fossil coral. The rocky bank along the shore between the Steamboat spring and our encampment, along which is dispersed the water from the hills, is composed entirely of strata of a calcareous _tufa_, with the remains of moss and reed-like grasses, which is probably the formation of springs. The _Beer_ or _Soda springs_, which have given name to this locality, are agreeable, but less highly flavored than the Boiling springs at the foot of Pike's peak, which are of the same character. They are very numerous, and half hidden by tufts of grass, which we amused ourselves in removing and searching about for more highly impregnated springs. They are some of them deep, and of various sizes--sometimes several yards in diameter, and kept in constant motion by columns of escaping gas. By analysis, one quart of the water contains as follows:
Sulphate of magnesia------------ 12.10 Sulphate of lime---------------- 2.12 Carbonate of lime--------------- 3.86 Carbonate of magnesia----------- 3.22 Chloride of calcium------------- 1.33 Chloride of magnesium----------- 1.12 Chloride of sodium-------------- 2.24 Vegetable extractive matter, &c-- 0.85 _____ 26.84
The carbonic acid, originally contained in the water, had mainly escaped before it was subjected to analysis; and it was not, therefore, taken into consideration.
In the afternoon I wandered about among the cedars, which occupy the greater part of the bottom towards the mountains. The soil here has a dry and calcined appearance; in some places, the open grounds are covered with saline efflorescences, and there are a number of regularly-shaped and very remarkable hills, which are formed of a succession of convex strata that have been deposited by the waters of extinct springs, the orifices of which are found on their summits, some of them having the form of funnel-shaped cones. Others of these remarkably-shaped hills are of a red-colored earth, entirely bare, and composed principally of carbonate of lime, with oxide of iron, formed in the same manner. Walking near one of them, on the summit of which the springs were dry, my attention was attracted by an underground noise, around which I circled repeatedly, until I found the spot from beneath which it came; and, removing the red earth, discovered a hidden spring, which was boiling up from below, with the same disagreeable metallic taste as the Steamboat spring. Continuing up the bottom, and crossing the little stream which has been already mentioned, I visited several remarkable red and white hills, which had attracted my attention from the road in the morning. These are immediately upon the stream, and, like those already mentioned, are formed by the deposition of successive strata from the springs. On their summits, the orifices through which the waters had been discharged were so large, that they resembled miniature craters, being some of them several feet in diameter, circular, and regularly formed as if by art. At a former time, when these dried-up fountains were all in motion, they must have made a beautiful display on a grand scale; and nearly all this basin appears to me to have been formed under their action, and should be called the _place of fountains_. At the foot of one of these hills, or rather on its side near the base, are several of these small limestone columns, about one foot in diameter at the base, and tapering upwards to a height of three or four feet; and on the summit the water is boiling up and bubbling over, constantly adding to the height of the little obelisks. In some, the water only boils up, no longer overflowing, and has here the same taste as at the Steamboat spring. The observer will remark a gradual subsidence in the water, which formerly supplied the fountains; as on all the summits of the hills the springs are now dry, and are found only low down upon their sides, or on the surrounding plain.