Seattle daily post-intelligencer. [volume] (Seattle, W.T. [Wash.]) 1881-1888, 1883-01-16

Tho ALLEGED nlipping Of The baGAltie
moantains toward The Celumbia Eivsr,
q tho point vhoco The river cuts
through the Cascade range, has been a.
txibuted to the dope II the underlying
aAndstooe. Il isRore probable that the
slip u upon one or both Of the pasty
co0Giomoeafe beds above and below the
aandrock. The structure Of the noun
tain has been studied by Professor J..
LoCouto, whose deocEipeioo b quoted
below IN the lassly publiGhed rspogt
Of Leutenaut Symcods' examination
Of tho Upper Columbia Tiveg.
There = found: ]. AlenG The Vatoe,o
edge, and for about fifteen fest upward,
very eoarDe euoRiomoIato az rounded
porphyritic pebbles and boWidefs Of Ill
aizss, up to ax fest IN diameter, coher-
ing by an impsrfectly lthi6sd earthly
paste.
2. Above this couRlomegate il . very
distinct. irregular OLD ground surface
bed, in which are found silicided
stumps, With their ROOFS spreading out
over twenty fest in diametsR, penstIAt-
ing into the bewlder material beneath,
and evidently IN sits. This i undoubt-
odly N old forest ground surface.
3. Rasting directly in thb ground
surface and therefore inolooinR the
erect stumps, ID Q layer of stEatihed
sandstone, two oe three fest thick, Alled
With beautiful impressions Of leaves of
several kinds Of forest trees, about
whose silicified bases they are found.
This layer is not continuous, like the
Rr0und surface on which il rests.
4 Above this stratified leaf bearing
layer rests ooayse onn9lomerate similar
to that beneath at the water level.
Scattered about IN the lower part Of the
upper oonalomeIate and in the strati1ed
sandstone. and sometimes lying in the
dirt bed beneath it, are fragments Of
trunks and branches Of oaks and conf
fers, in silieif1ed or liRnitlxed condi-
ton. They are evidently silioihsd
driftwood.
5. Above this last conelemorate, and
resting upon it, Yise the layers Of lava,
mostly oolumnar basalt, ono above an
other, to the hight Of moro than 5000
fest.
The history Of these formations Pro
feseor L. Conte reads - follows:
l. Tho region Of the Columbia river
Va . forest, probably . valley over.
grown BY oooifegs and oaks. The sub
soil Of this forest was . coarse bowlder
drift produced BY erosion from older
rocks.
2. By excess of water, either By foods
or changes Of level, the trees we're killed,
and their leaves shed and buried in the
mud, and their trunks rottsd to stumps.
8. Tumultuous and rapid deposit Of
o0arae drift containing driftWood Gov
erod mp The forrest ground and the still
remaining stumps. ono hundred, par
hAps several hundred, feet in thick
1. The surface thus formed vas sro-
ded into hills and dales.
8. Then followed the outburut Of lava
in successive flows perhaps for . long
period Of time, and the silicihcatiou Of
the wood and tho oomentation Of the
dFift BY the psroolation Of hot alkaline
waters containing silica, - happens %
commonly in sub-lava drifts.
6. Finally followed the process Of
erosion By which the present stream
channels, whether main or tributary,
have been out 70 their ENORMOUS depth.
The outflow Of Lava which forms the
bulk Of the mountain was probably the
grandest and most Extraordinary lava
now that ever took place. Il covered
an area Of about 100000 Uqnare miles to
an average depth Of something like
1000 fest. 1ts greatest depth Was not
le0 than 800 feet.