68 



GEOLOGICAL SURVEY OF THE TERRITORIES. 



the northwest margin of the main terrace there is an example of what 

 I have called an oblong mound. There are several of them here, extend- 

 ing in different directions, from fifty to one hundred and fiftj' yards in 

 length, from 6 to 10 feet high and from 10 to 15 feet broad at the 

 base. There is in all cases a fissure from one end of the summit to the 

 other, nsually from 6 to 10 inches wide, from which steam sometimes is- 

 sues in considerable quantities, and as we walk along the top we can 

 hear the water seething and boiling below like a cauldron. The inner 

 portion of this shell, as far down as we can see, is lined with a hard, 

 white enamel-like porcelain ; in some places beautiful crystals of sulphur 

 have been precipitated by the steam. These have been built up by a 

 kind of oblong fissure-spring in the same way that the cones have been 

 constructed. The water was continually spouting up, depositing sedi- 

 ment around the edges of the fissure until the force was exhausted, and 

 then the calcareous basin was rounded up something like a thatched 

 roof by overlapping layers. 



Near the upper terrace, which is really an old rim, are a number of 

 these extinct, oblong geysers, some of which have been broken down so as 



Fig. 15. 



to show them to be 

 a mere shell or cav- 

 ern, which is now 

 the abode of wild 

 animals. (Fig. 15.) 

 I attempted to en- 

 ter one of them, 

 and it was full of; 

 sticks and bones 

 which luid been 

 carried in by wild 

 beasts, and swarms 

 of bats flitted to 

 and fro. Some of; 

 them have been 

 worn away so that p 

 sections are ex- p; 

 posed, showing the 8-^^ 

 great number and """""^^-^ 

 thickness of the overlapping layers of sediment. 

 Some of these mounds are overgrown with pine- 

 trees, which must be at least eighty to a hundred -ju^ji 

 years old. Indeed, the upper part of this moun- 

 tain has the aspect of a mag'nificent ruin of a extinct oblong geysers. 

 once flourishing village of these unique structures, now fiist decompos- 

 ing, even more beautiful and instructive in their decay. We can now 

 study the layers of deposit, which are sometimes revealed by thou- 

 sands on a single mound, as we would the rings of gTowth of a tree. 

 How long a period is required to form one of these mounds, or to 

 build up the beautiful structure which we have just described, I have 

 not the data for determining. Upon the middle terrace, where the 

 principal portion of the active springs are at the present time, some 

 of the pine-trees are buried in the sediment apparently to the depth of 

 or 8 feet. All of them are dead at the present time. We have evi- 

 dence enough around the springs themselves to show that the mineral- 

 water is precipitated with great rapidity. I think I am safe in believing 

 that all the deposits in the immediate vicinity of the active springs are con- 

 stantly changing from the margin of the river to the top of the White 



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