pkale.] DESCRIPTIVE GEOLOGY — SODA SPRINGS, &C. 591 



are two small vents, from which hot air and gas escape. The tem- 

 peratures here were 83° F. and 85° F. There is a great deal of old 

 deposit surrounding these springs, and the remnants of spring basins, 

 in which the springs have long been extinct, are seen in many places. 

 On the opposite side of the Bear several reddish and yellowish cones or 

 chimneys are still standing. 



A small bluff just above the Steamboat Spring has a curious bright-yel- 

 low tufa, with a coral-like structure, which has been deposited by springs 

 in times long past. It is calcareous, 1 colored with iron. The whole bank 

 of the river for some distance is macle up of tufa. Even some distance 

 back from the river there is but little soil, the hard tufa forming most 

 of the surface, covered in many places with a saline efflorescence. 



Above the mound of yellow tufa, a creek comes in, which we will call 

 Basin Creek, as the large spring at the head of it was called Basin Spring 

 by Fremont. 



Basin Creek. — Near the mouth, in a gully about 300 yards from the 

 Steamboat Spring, is a spring about three feet in diameter. There is no 

 iron deposit ; and the water has a sharp, sweetish taste, with a slight 

 escape of carbonic-acid gas. Its temperature was 50° F., with the air 

 at 79° F. This spring I have named Cold Spring. Near it is a small 

 hole, from which gas escapes through the water with considerable noise. 



Near the head of the creek there are several springs, some of which 

 are ordinary cold springs. The largest spring is Basin Spring. This 

 spring was not visited by us this year. The following description was 

 given in the Beport for 1871 (p. 152) by Dr. Hayden : 



Near the foot of the hills, a mile from the river, there is a soda spring, with a mound 

 about 10 feet high, with a large rim 30 by 100 feet, but with a small quantity of water 

 compared with what formerly flowed from it ; temperature, 53^°. Near this spring 

 arc a number of large springs issuing from beneath the hills of limestone, without the 

 deposit or the taste of the acidulous ones, so that we have in close proximity, and 

 apparently coming from the same rock, with about the same temperature, acidulous 

 and non-acidulous springs. There were two springs the waters of which were above 

 the ordinary temperature, respectively, 76^° and 78°. ' 



This spring is without doubt the same one described as follows by 

 Fremont :* 



Descending the mountains and returning towards the camp along the base of the 

 ridge which skirts the plain, I found at the foot of a mountain spur, and issuing from 

 a compact rock of a dark blue color, a great number of springs having the same pungent 

 and disagreeably metallic taste already mentioned, the water of which was collected 

 into a very remarkable basin, whose singularity perhaps made it appear to me very 

 beautiful. It is large — perhaps 50 yards in circumference — and in it the water is con- 

 tained at an elevation of several feet above the surrouuding ground by a wall of cal- 

 careous tufa, composed principally of the remains of mosses, three or four, and some- 

 times ten feet high. The water within is very clear and pure, and three or four feet 

 deep, where it could be conveniently measured near the wall ; and at a considerably 

 lower level is another pond or basin of very clear water, and apparently of consider- 

 able depth, from the bottom of which the gas was escaping in bubbling columns at 

 many places. This water was collected into a small stream, which in a few hundred 

 yards sank under ground, reappearing among the rocks between the two great springs 

 near the river, which it entered by a little fall. 



A 



On the eastern branches of Basin Creek there are several springs, in 

 which the water is cold and of agreeable taste. In 1871 some of these 

 were named and temperatures taken as follows : 



Rill Springs, 56J° F., 58° F., 53£° F.— These are situated at the end 

 of a ridge northwest of the west village. 



Left-Rand Springs, 54£° F., 52£° F. — These are northwest of the Beer 

 Springs. 



Beer Springs. — The Beer Springs, as named by Fremont, are on the 



* Fremont's First and Second Expeditions, l842~'43-'44 ; p. 138. 



