590 EEPOET UNITED STATES GEOLOGICAL SUEVE5T. 



of the Bear River Valley on the east side from Georgetown to Soda 

 Springs. Mount Prenss is the culminating point in the range and at- 

 tains an elevation of 9,070 feet. To the southward the range soon falls 

 off and the Jurassic limestones curve over the ridges in a series of folds, 

 probably not more than two in number. This region was not crossed, 

 and we have, therefore, no geological data to present in regard to it. 

 • The slopes of the range are well timbered, and give the settlers in 

 the valley a good source of supply for pine wood. The principal streams 

 draining the southern portion of the range are Twin Creek and Tullock's 

 Fork, or Davis' Creek. The latter in reality drains the ridges just 

 south of the range. Between the two creeks are several streams, which 

 in the spring furnish water for irrigation. Late in the summer most of 

 them are without water. 



The nucleus of the range, as we have already noted, is Carboniferous, 

 the limestones being very sharply folded 'towards the north. Jurassic 

 limestones and sandstones, with beds of quartzite, are, however, the pre- 

 vailing rocks. Their southern prolongations were crossed in the cation 

 of Bear Biver north of the Bear Lake Plateau. 



The section of the beds at the latter point has already been given, and 

 the sections north of Mount Preuss will be found in the preceding 

 chapter. 



SODA SPEINGS AND BEAE EIVEE BEND. 



The soda springs at the bend of Bear Biver have long been known, 

 as the old Emigrant Road passes by them. On account of the effervescing 

 gas and jdeasant pungent taste of the water in some of the springs, they 

 were known as the Beer Springs. Most of the springs are cold, only 

 one or two properly deserving the name of thermal springs. The prin- 

 cipal one is the one named the Steamboat Spring by Fremont. 



Steamboat Spring. — This spring is on the bank of the river, near the 

 edge of the water. It has a small cone about two feet in diameter, 

 rising several inches above the surrounding level. The opening is coated 

 with a bright red deposit of iron. There is a large escape of carbonic 

 acid gas, which agitates the water so violently that it appears to be 

 boiling. It is thrown about two feet at the highest, although this is 

 only at intervals. It is accompanied by a subterranean noise, from 

 which tact it was named. The deposit is hard and almost like porcelain. 

 An analysis is given in Fremont's Report,* which is quoted below. 



Analysis. 



Carbonate of lime 92. 55 



Carbonate of magnesia 0. 42 



Oxide of iron .' 1. 05 



Silica ) 



Alumina > 5. 98 



Water and loss ) 



100. 00 



The water is not very agreeable in taste. It is slightly sharp, with a 

 metallic and sweetish taste. Its temperature at 1.30 p. m., when the 

 air was at 80° F., was 88° F. The following day it was 87f ° F. In 1871 , 

 the temperature was given as 85£° F. The difference is probably due 

 to a difference in thermometers, the temperature given by Fremont 

 is 87°, showing that there has been but little or no change in the tem- 

 perature. There is a very slight overflow of water. Near this spring 



* Fremont's First and Second Expeditions, 1842-43 and '44. - 



