PEALE] SPEINGS ON S. W. AEM OF YELLOWSTONE LAKE. 119 



These mud puffs resemble closely the mud puffs in the Fountain 

 Group of the Lower Geyser Basin of the Fire Hole. The center of the 

 basin is depressed in the same manner, and the mud cones or mounds are 

 similar. The mud forming the latter has about the consistency of putty. 

 The variation in the character of the mud springs, as I have mentioned 

 in previous reports, depends on the amount of water supplied to the 

 springs. When we saw these springs the mud was thick and tough. 



In the immediate neighborhood of the mud puffs are numerous mud 

 springs of all consistencies. Some are simply turbid springs •, others 

 have thin muddy water of white, red, or yellow colors, and some are 

 thick mud springs resembling mud puffs. 



One red turbid spring gives a temperature of 190° F. ; a white one 

 north of it is 182° F. ; a second white one 142° F. ; and other turbid 

 springs have temperatures of lo4o F., 176o F., 132° F., 174° F. In the 

 south end of this subgroup the temperatures are 190° F., 146° F., 163° F., 

 1850 F., and 168o F. 



North of these are clear springs of 10 to 50 feet diameter and 40 or 

 50 feet depth, usually with funnel-shaped orifices. In some of these the 

 ultramarine and sea-green tints are beautifully shown. They are prob- 

 ably pulsating springs. One is particularly noticeable, having a diame- 

 ter of about 50 feet and a temperature 173° F. Further north the springs 

 are lake-like in character, the water standing over large areas. In 

 many of the springs the soft leathery -looking substance noted in the 

 Shoshone Basin and in the Geyser Basins of Fire Hole Eiver is abun- 

 dant. The surface is generally brilliant in color, while underneath it 

 is brown or black. It tills some of the basins to a considerable depth, 

 although on the surface it is about 2 inches in thickness. It resembles 

 jelly in some places, and is no doubt ^'- viandite,''^ the new variety described 

 by Mr. Golschmith in Part III of this report. In some of the lower lay- 

 ers it is seen in a solidified state, and is more like the harder varieties 

 of other varieties of the geyserite. 



Still further north the temperatures of twenty-four or twenty-five 

 springs were taken and found to range from 140° F. to 185° F. 



The character of the deposits about the silicious springs of this local- 

 ity is not so fine as in the Fire Hole Geyser Basins, and the ornamenta- 

 tion is much less. Dr. Heizmann, speaking of this group, says "the 

 temperatures range from 70° to 180°, and all evolve carbonic acid; a 

 few only sulphureted hydrogen."* He gives the deposits as silica, iron, 

 alumina, magnesia, lime, soda, sulphides, sulphates and chlorides, and 

 classes the springs with those of the Fire Hole Yalley.t 



Kone of the specimens of the silicious deposits collected by us have 

 ever been analyzed. The mud I found in 1871 contained iron, alumina, 

 lime, and silica. Specimens of the mud collected by the Washburn 

 Doane party in 1870 were analyzed and found to contain silica and 

 alumina as the principal constituents. These analyses will be given in 

 Part III of this report. 



Underneath the silicious deposits which line the shore of the lake at 

 this locality are modern lake depo.sits — sandstones composed of disin- 

 tegrated volcanic rocks (obsidian, &c.) and indurated clays. 



Upper Groiip. — I did not visit this grouj) in 1871, and the following 

 description is taken from Professor Oomstock's report, he having seen 

 them in 1873, before he came to the Lower Group : 



Like most of the collections witliin tlie limits of tlie ancient lal<o basin, this cluster 

 contains a number of bowls, which emerge directly from the silty deposits, the cou- 



*Ecport of Eecouuaissance of N.W. Wyoming, by Capt. W. A. Jones, 1873, p. 304. 

 . ilbid., p. 304. 



