THE LAVA BEDS. 307 



The lava beds, where the Indians were encamped, are a 

 very extraordinary formation. The valley on which we 

 looked down was about two miles across, opposite to us, 

 with a bounding ridge of rugged mountains on each side 

 of it ; and was, from side to side and for its entire length, 

 a solid sea of lava billows. The lava covered the entire 

 valley. This lava deposit was of inconsiderable depth at 

 its edge, close to the foot of the mountains ; but as it had 

 filled up all hollows and depressions in the ground to a 

 general level, was of very varying thickness. In the centre 

 of the valley it was from one to two hundred feet thick, 

 occasionally much thicker, as shown by that being the depth 

 of tne main fissures in it. These fissures were clefts from 

 the surface of the lava down to the bed-rock of granite, 

 which formed the structural floor of the valley, and they 

 varied in width from a stone's-throw to hundreds of feet ; 

 and the inequalities of their almost perpendicular opposite 

 sides had such complete correspondence to one another, 

 that the fissures looked as if they had only just opened. 

 These main fissures were joined by numbers of large and 

 small lateral ones, for all tho clefts in the lava converged 

 and united one into the other, until ultimately there was 

 but one the Black Canon. The immense depth and 

 volume of lava in the valley inferred the fact that it was 

 the accumulation of a flood, during a geological period, 

 from now long since extinct volcanoes. Whether the fis- 

 sures were the result of contraction on cooling, of earth- 

 quakes, or of a gradual expansion, caused by slow upheaval 

 of the granite floor on which the lava rested, or of all these 

 causes or some unsuggested one, I am not capable of 



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