80 EEPOET UNITED STATES GEOLOGICAL SURVEY.' . 



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Twelfth terrace. — This was the seat of very active springs in 1872, 

 which were not there in 1871. They are now dying out again. The 

 springs are at two different levels. A slight terrace between them has 

 at present no springs, although the snowy-white basins show that it is 

 not long since they disappeared. 



Kos. 25, 2G, and 27 are on the lower level. 



IsTo. 26 marks the location of several small holes that bubble in a space 

 of about 3 feet diameter, surrounded with a reddish deposit on which 

 there are the soft silky filaments. There is considerable overflow, and 

 one of the holes bubbles spasmodically, giving off sulphureted hydro- 

 gen gas. The water spreads out in a pool. 



No. 25 marks the place of three small fissures. The flow of water is 

 very small, and it soon spreads out on the flat surface of the deposit 

 and disappears. 



No. 27 is a raised mound, and on the summit is the spring with a tem- 

 perature of 1GU° F. There are three bubbling points at the base of the 

 mound. 



No. 28 is on the upper level, on the summit of a mound measuring 35 

 feet by 40, with white basins on its front. It is a white spring, and has 

 a coating of lime carbonate on the surface. The water has a tempera- 

 ture of 142° r. Back of these springs is the bluff of the thirteenth 

 terrace. 



At the foot of the narrow ridge which separates the eleventh from the 

 twelfth terrace are two oblong mounds that in 1872 had some of the 

 most active springs of the twelfth terrace. They appear to have ceased 

 flowing recently, judging from the appearance of the deposit. By re- 

 ferring to the table of springs it will be seen that of the eight temi^era- 

 tures taken only one was at all high, and it was only 160° F. Of the 

 eight temperatures taken in 1872 three were 162° F., and five 160° F. 



Thirteenth and fourteenth terraces. — For the purpose of description 

 these two terraces may be considered as one, with a very irregular sur- 

 face. As seen from the surrounding hills it presents a quite uniform 

 surface back for some distance, and its edges, fronting the wagon road 

 and the eleventh terrace, are fringed with old empty basins. It must 

 once have been a prominent part of the springs, far exceeding the pres- 

 ent state of the ninth terrace, to which it bears some resemblance. "When 

 it was the seat of active springs the eleventh terrace held the same re- 

 lation to it that the area about the Liberty Cap does to the ninth terrace, 

 the mounds and ridges on the eleventh terrace corresponding to the 

 Liberty Cap and Bee Hive. The mounds and ridges on the back part 

 of the nineteenth terrace hold the same relation to the old terrace, the 

 bluff face of which now forms the upper limit of the active springs. This 

 old terrace is concealed by the very heavy growth of timber which covers 

 its sides, but traces of old basins can still be seen along the wagon- 

 road which goes up over it. Back of the level portion of the thirteenth 

 tei?racethe surface is broken into hollows and ridges, all heavily timbered. 

 Beyond these is what was described as the fourteenth terrace in 1872. 

 At some places, particularly near Glen Grotte, its level is slightly below 

 that of the thirteenth terrace. On the west side of the latter a ridge 

 with a fissure, like the one on the ninth terrace, rises above the road. 

 This must once have been the site of active springs. The slopes facing 

 the wagon-road are covered with old gray basins. At the summit a 

 little steam still escapes. On the east side of the terrace, at the edge 

 of the bluff overlooking the twelfth terrace, there have been active springs 

 recently. There are fissures in the deposit, from which there is a slight 

 escape of steam. 



