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53
was derived from far older sources because in what appears to be the oldest & the youngest of the present group of cones, have a scanty mixing of glacial drift down in their deepest mouths & also up their sides. these boulders give evidence of having been subjected to great [immense] heat & are of a size & kind exactly corresponding to those forming the stratum in the plains on Rush Creek.
It seems impossible to account for the presence of these boulders in any other way than by supposing that they were erupted with the rest of the lava which forms the cones after the deposition of the lower volcanic stratum & of the thin deposit of boulders thus
[sketch of a cross section of earth]
54
Aug [August] The cone nearest the lake on the south side, is encompassed by a [very] regular circular embankment, which seems to be the base of an older crater, because there is no apparent difference between this embankment & the older cones to the south either in size slope or [sketch of a cone inside a crater] in the physical condition of the matter of which they are composed.
[sketch: Section of circular embankment showing the acuteness of angle at top & of the angle at which the sides of inner cone & embankment meet.]
Should any one of the older volcanoes of the range become active in a moderate degree & subside exactly such a ring would be formed
Date Original
November 1869
Source
Original journal dimensions: 10 x 16.5 cm.
Resource Identifier
MuirReel23Journal04P53-54.tif
Publisher
Holt-Atherton Special Collections, University of the Pacific Library
Rights Management
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Keywords
John Muir, journals, drawings, writings, travel, journaling, naturalist
