340 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



that six miles from Laodicea, at the site of the ancient city of Hierapo- 

 lis. The genera] resemblance to the Mammoth Hot Si)rings of Gardiner's 

 Eiver, in the Yellowstone Park, which are also calcareous, will be appar- 

 ent from the following description by Prof J. Lawrence Smith:* 



SPRINGS OF ITIERAPOLIS. 



The site is seen for many miles before it is reached, as it rises abruptly from the 

 north side of an extensive plain, and the sides of the hill are covered with an incrus- 

 tation of dazzling whiteness for upward of a mile in length, and from this it has re- 

 ceived its present name, Panbiik-Kelescy (cotton castle). Its thermal waters have 

 always been its principal object of note, as evinced by the extensive ruins of baths. 

 In fact, the very hili upon which the city stands owes its formation to the deposition 

 of carbonate of lime from these waters, and it now rises upward of a hundred feet 

 above the plain, with a width of about six hundred feet. Immediately behind the 

 city rises another set of hills of calcareous rock, Irom which flow the waters in ques- 

 tion. * * * The amount of water is very great, aud it is so highly charged with 

 carbonate of lime as to incrust all bodies that it comes in contact with ; and it takes 

 place so rapidly that the concretion does not possess great solidity, and frequently has 

 a granular form, resembling driven snow. 



In some places, as the waters flow over the steeply-inclined sides of the hill, it forms 

 a succession of terraces at regular distances, that require but little eflbrt of the im- 

 agination to liken to an amphitheater with its marble seats. At other places it flows 

 over the precipitous sides 64 or 70 feet high, and 100 or 2U0 feet wide, incrustiug the 

 precipice with a snow-white sheet, which might be likened to a consolidated cataract ; 

 and, what adds to the delusion, at the base the incrustations have accumiilated an 

 irregular mass not unlike foam. This petrified stream extends several hundred feet 

 into the plain. It has formed walls and dikes, and incrusts the grass and vegetation 

 that it flows over, and many of the tufts of grass, in perfect verdure, are thickly in- 

 crusted near the roots with this white carbonate of lime. 



Strabo, speaking of these springs, says that the people of the city 

 conda(;ted the waters along the vineyards and gardens wherever they 

 wanted a wall, and the channels became long fences, each a single stone, 

 formed from the deposits left by the water. 



In the deposits, as described above, we have the same arrangement 

 in terraces that we have seen in the Mammoth Hot Springs of the 

 National Park and the Tetarata of New Zealand, and in all three there 

 is the general resemblance to a frozen cascade. A photograph of the 

 Hierapolis deposits in "Anatolica"t (opposite page 99) shows that the re- 

 semblance to the Gardiner's River Springs is striking. Similar small 

 basins are seen on the sides of the main mass, although the latter does 

 not appear to be so extensive as the main terrace at Gardiner's Eiver, in 

 the Yellowstone Park. 



ASIA. 



There are said to be about twenty-four volcanoes in Asia, twelve of 

 them being in Kamtscb atka. The volcanic line extends through Central 

 Asia mainly between Siberia and China, turning southward and east- 

 ward into Turkestan. The distribution of thermal springs corresponds 

 with the extension of this volcanic line. Thermal springs are found in 

 Kamtschatka, in Southern Siberia, and in Turkestan and North ern Per- 

 sia, south of the Caspian Sea. In the latter region there is a region 

 called the "Field of Fire," reminding us of our own "Fire Hole" in the 

 Yellowstone Park. The plains of Siberia appear to be destitute of 

 thermal springs. It is not until the mountainous parts are reached that 

 they are found. Many springs that in other places would be cold ought 

 to be considered as thermal springs in Siberia. Thus, at Slatoust, 

 Aleski, and Tomsk there are springs that never fi?eeze, although the 



* In " Original Researches: The Thermal Waters of Asia Minor," page 98. 

 t Anatolica, by Rev. E. J. Davis, LondoUj 1874. 



