176 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



Table of Eighth or Sentinel Group. 



1 



Name. 



Size of spring. 



a 



CO 







Eemarts. 



1 



riatCone 



Small Cone 



Rosette Geyser 





°p. 

 200 



165 

 196* 



198 



190 

 195t 



199 



199 



201 

 al94 

 6195 



190 



«132 

 6140 



175 



193 



al90 

 199 



198 

 135 



197 





o p. 



This spring is on a high 

 mound. Water rises and 

 falls ; boiling, periodical. 



^a■ 



10 inches diameter 



Basin 20 feet diameter, 

 geyser 1 by 2* feet. 



Two openings, each 

 about a foot diameter. 







2 









3 







sette-like pebbles; spouts 

 10 to 30 feet. 

 Tellow-lined. oblong, flat 

 mound. 



4 









fi 











Beaded mound, 6 inches 

 high. 



Irregular, yellow-lined 

 hole ; mound 1 foot high. 



This spring is on a high 

 mound like No. 1. It 

 boils vigorously, and 

 sometimes bulges a foot 

 or more. 



Boiling spring like 187; 

 mound is flatter ; a and 

 b are vents alongside. 



Lake-like spring, bulging 

 at one end. 



Green-lined pool, circular 

 at each end. It is in 

 timber. 



Whi te basin, lined -with yel- 

 low globular masses. 



Sloping, beaded edge; bub- 

 bles. 



Yellow-beaded silica sepa- 

 rates the two openings, 

 and a yellow and red 

 water-way carries off the 

 overflow. 



fi 











7 



Steep Cone 



Mound Spring. 

 Eed Terrace . . . 



8 feet diameter 



9.45 am... 



45 



8 



12 by 15 feet 



9 



60 by 20 by 25 feet 



40 by 25 by 18 feet, dou- 

 ble spring. 



Basin is 6 feet diameter, 

 18 inches deep; tissuro 

 in center 2 feet by 6 

 inches. 



2by 3feet 







in 







n 





10.45 a. m. 



49 



^•i>, 





13 



Bulgers 







49 



u 









15 





3 by 5 feet 







Clear spring, with mud- 

 holes beyond iL 



16 























near by. 



At low water. 



f "With water down. 



DESOKIPTION. 



^0. 1. Flat Cone. — This is the first spring met with on the north side 

 of the valley. It is on the top of a mound of gray geyserite that rises 

 between 15 and 20 feet above the surrounding level, and has a diameter 

 of about 55 feet on the summit. It is of course much larger at the base. 

 It was named Flat Cone Geyser in 1872, although mound would be a 

 better designation than cone. I do not think it is a geyser, as the spring 

 on the summit is regularly agitated, and the surface of the mound shows 

 no evidence of any spouting. The spring basin on the summit of the 

 mound has a diameter of about 9 feet, and has a dark brown rim which 

 is raised 6 to 8 inches. The water rises and falls, and has periods of 

 very active ebullition. The temperature of the water was 200° Y. The 

 temperature obtained by Professor Bradley in 1872 was 197° P. Just 

 outside of the spring is a small cone 10 inches in diameter and a foot in 

 height, in which the water has a temperature of 165° P. The spring is 

 not in the center of the mound, but near one side, and outside the mound 

 has considerable standing water. 



