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Washburn
Report Index
YELLOWSTONE EXPEDITION OF 1870
Page 28
edges a deep fringe of rock, the points of which
finally meet across the openings of the craters, forming a sort of sieve,
which finally closes entirely, forcing the waters to break out in some other
place. Numbers of these self-extinguished craters are seen scattered along
both banks of the stream, having now become cones of solid rock. Most of the
waters are clear, and the deposits are usually calcareous, but we found a
few springs of water resembling ink, for which the deposit was a black hard
rock, composed largely of silica, and extremely flinty, shattering the
blades of our hatchets, and giving forth showers of sparks when struck by
them. The valley here descended rapidly, and we soon saw in front dense
columns of steam rising above the hills. After traveling two miles among
these springs of various kinds, and through several bogs on the slopes, we
came suddenly upon an open rolling valley of irregular shape, about two
miles in width and three in length. This valley is known in the wretched
nomenclature of this region as the Firehole, and contains phenomena of
thermal springs unparalleled upon the surface of the globe. Crossing the
river we moved down to a central point of the valley, and camped in a little
grove of pine timber near the margin of a small marshy lake, around which
were to be seen numerous fresh signs of buffalo, driven out by the noise of
our hasty intrusion. Distance 6 miles.
Barometer, 22.70; thermometer, 40°; elevation,
6,626 feet.
The valley is of triangular shape, with an obtuse
angle on the south side of the river, which runs parallel with its longer
side, and about three hundred yards from the foot of the range. At the apex
of the obtuse angle a stream 50 feet wide comes in from the south, joining
the main river in the midst of the valley, below its central point. The
mountain ridges on all sides are 1,500 feet in height, composed of dark
lava, in solid ledges, are heavily wooded, and very steep. Small groves of
timber also cover the highest points of the valley, which is a succession of
ridges, and of rounded knolls capped by springs, the intervening depressions
being rendered marshy by the overflow of their waters. The whole surface of
the basin, to an unknown depth, is a calcareous bed, deposited from the
springs. Near the head of the valley, immediately after crossing to the
south side of the river, we came to one of the geysers, which was at the
time throwing water, with a loud hissing sound, to the height of 125 feet.
In a few minutes the eruption ceased, and we were enabled to approach the
crater. This had originally been a crack or fissure in the calcareous ledge,
the seam of which could be traced by minute vents a distance of 60 feet, but
was now closed up by deposits from the water to an opening 7 feet long by 3
feet wide in the center, from which the steam escaped with a loud, rushing
sound. The hillock formed by the spring is 40 feet in height, and its base
covers about four acres. Near the crater, and as far as its irruptive waters
reach, the character of the deposit is very peculiar. Close around the
opening are built up walls, 8 feet in height, of spherical nodules, from 6
inches to 3 feet in diameter. These, in turn, are covered on the surface
with minute globules of calcareous stalagmite, incrusted with a thin glazing
of silica. The rock, at a distance, appears the color of ashes of roses, but
near at hand shows a metallic gray, with pink and yellow margins of the
utmost delicacy. Being constantly wet, the colors are brilliant beyond
description. Sloping gently from this rim of the crater in every direction,
the rocks are full of cavities, in successive terraces, forming little
pools, with margins of silica the color of silver, the cavities being
irregular shape, constantly full of hot water, and precipitating delicate
coral-like beads of a bright saffron. These cavities are also fringed with
rock around the edges, in
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