GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 



Fig. 15. 





iM**'i 



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 fifty 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, usually from 6 to 10 inches wide, from which steam sometimes is- 

 sues in considerable quantities, and as we walii 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 ft 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-spriug 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. 



Xear 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 

 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 fall of' 

 sticks and bones | 

 which had been 

 carried in by wild 

 beasts, and swarms 

 of bats flitted to 

 and fro. Some of 

 them have been 

 worn away so that 

 sections are ex- 

 posed, showing the 

 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 

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

 tain has the aspect of a magnificent ruin of a 

 once flourishing village of these unique structures, now fast 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 growth 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 

 6 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 



EXTINCT OBLONG GEYSERS. 



