120 



REPORT UNITED STATES GEOLOGICAL SURVEY. 



tents of whicli are, therefore, more or less contaminated liy the admixture of iusoluhle 

 ingredients. Near the lower end of the group a small, muddy flat ruus back from the 

 shore, which appears to have been the bed of an ancient stream, if not the channel of 

 a recent creek during seasons of flood. On this are situated several mud bowls and a 

 number of orifices of smaller dimension, in which the agitation is not powerful enough 

 to render the contents turbid. Nearer the shore there are several large, clear, or 

 nearly clear, springs, which constantly overflow, sending their surplus into the lake. 

 The little stream which carries oft" the waste is so highly heated that one cannot bathe 

 with comfort in its track, except by wading for some little distance into the lake before 

 venturing opposite its entrance. Several mud pots occur at a higher level, just norlh 

 of the flat on which the above are located. South of this point, at a still higher level, 

 there are what may be called three clusters of springs, although They are not widely 

 separated. The first collection comprises a set of half a dozen bowls of varying dimen- 

 sions, which emerge from the summit of a kind of terrace of old hot spring deposits, 

 15 feet above the level of the lake at low water. In several of these the vapor issues 

 with considerable force, but with a seething rather than a puffing sound. 



One spring has a large bowl about 4 feet in diameter. Back of these the members 

 of the second cluster issue from a silty area, for which reason the contents are mostly 

 turbid or muddy. The third group is further from the lake and more elevated than 

 the others, and may be said to combine, in a measure, the features of them all. Tiie 

 products are as varying as the varying character of the springs would suggest. The 

 mud pots deposit about the usual proportion of ferric hydrate in addition to the 

 other ingredients, and the amount of iron dissolved in the water of the clearer springs 

 is apparently large, judging from the amount of colloid and confervoid growth, which 

 exists wherever favorable conditions are x>resent for such accumulations. The orna- 

 mentation of the margins of the clearer bowls is comparatively simple, and raised 

 rims are almost entirely absent. Hydrated alumina is a prominent ingredient, and in 

 some of the ancient deposits it is blended and intermingled with the silicious accumu- 

 lations in a very interesting manner. In the past, as now, there has evidently been a 

 close connection between this group of springs and the Yellowstone Lake, for all the 

 bowls are situated in a section which has been worked over by the beating of the 

 waves upon a beach, and the ancient deposits have been greatly modified since their 

 formation by the same action.* 



Eeeapitulation of springs of Yellowstone Lake. 



Ifame. 





Snlphur Hills Group . . . 

 Turbid Lake Group . . . 



Steamboat Springs 



Mary's Bay Group 



Lake Butte Springs 



Brimstone Basin 



Springs on West Arm . 



Total number of springs. 



10+ 

 11+ 



7+ 

 10 



7 



66 

 112+ 



°F. 



190 

 192 

 192 

 192 



So far as known, we have no large geysers in the groups of springs 

 surrounding Yellowstone Lake. 



CHAPTEK V. 



PELICAN CREEK SPRINGS. 



The springs on Pelican Creek may be divided into three groups, ac- 

 cording to their location, viz, '^ Lower Group," "Three Forks Group," 

 and "West Pelican Springs." 



Lower Group. — Dr. Hayden, in 1871, visited these springs, which are 



* Report of Reconnaissance of N. W. Wyoming, by Capt. W. A. Jones, 1873, pp. 

 233, 234. 



