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I even thought, with many other geologists, that obsidian, so far from being vitrified lava, belonged to rocks that were not volcanic; and that the fire, forcing its way through the basalts, the green-stone rocks, the phonolites, and the porphyries with bases of pitchstone and obsidian, the lavas and pumice-stone were no other than these same rocks altered by the action of the volcanoes.
Barker to tell you about that. McLean drifted to Green River last year and went up over on to Snake, and up Snake, and was around with a prospecting outfit on Galena Creek by Pitchstone Canyon. Seems he got interested in some Dutchwoman up there, but she had trouble died, I think they said and he came down by Meteetsee to Wind River. He's liable to go to Mexico or Africa next."
Most of these dikes are coated by a glossy layer, from one to two-tenths of an inch in thickness, which, unlike true pitchstone, fuses into a black enamel; this layer is evidently analogous to the glossy superficial coating of many lava streams.
It was the Virginian who came back, and as he stood at the foot of my blankets his eye, after meeting mine full for a moment, turned aside. I had never seen him look as he did now, not even in Pitchstone Canyon when we came upon the bodies of Hank and his wife. Until this moment we had found no chance of speaking together, except in the presence of others.
'Twas plain to see he'd got a genu-wine scare comin' through Pitchstone Canyon, and it turned him sour, so he'd hardly talk to us, but just mumbled 'How! kind o' gruff, when the boys come up to congratulate him as to his marriage. "But Willomene, she says when she saw me, 'Oh, I am so glad! and we shook hands right friendly. And I wished I'd told her good-bye that day at the Mammoth.
Secondly, small irregular nodules of the obsidian, either standing separately, or united into thin layers, seldom more than the tenth of an inch in thickness, alternate repeatedly with very thin layers of a feldspathic rock, which is striped with the finest parallel zones of colour, like an agate, and which sometimes passes into the nature of pitchstone; the interstices between the nodules of obsidian are generally filled by soft white matter, resembling pumiceous ashes.
Lin was unsaddling and looking after my horse, just because he was glad to see me. Since our first acquaintance, that memorable summer of Pitchstone Canyon when he had taken such good care of me and such bad care of himself, I had learned pretty well about horses and camp craft in general. He was an entire boy then.
There is also much imperfect rubbly pitchstone, with the interstices charged with powdery carbonate of lime apparently of contemporaneous origin. These lavas are conformably associated with strata of breccia and of brown tuff containing lignite. The whole mass has been broken up and tilted at an angle of 45 degrees, by a series of great volcanic dikes, one of which was thirty yards in breadth.
In a hand specimen, this substance would certainly be mistaken for a pale and peculiar variety of pitchstone; but when seen in mass its stratification, and the numerous layers of fragments of basalt, both angular and rounded, at once render its subaqueous origin evident.
The surface of this lake is 1,250 feet above that of the ocean, and its margin is enclosed within a border of rhyolite and pitchstone rising into a mass of the same material 1,800 feet high on the eastern side. The form of the lake does not suggest that it is itself the crater of a volcano, but rather that it was originated by subsidence.
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