Wessington Springs herald. (Wessington Springs, Aurora County, Dakota [S.D.]) 1883-1891, 1889-01-04
GREAT .LATA FLOOD.
HO,r the Columbia Rirer Makes It's Wa
ThrOsxah the Cascade RaMae.

GREAT Lava FLOOD.
I5o'r the Columbia Rirer Makes its Way
Through the Cascade Range.
The Central and Eastern parts of
Oregon are vast bed Of lava, which
covers, according to Prof. La Conte, be-
tween 20O, 900 and 100000 square miles
of territory. 1t is probably the most
extraordinary lava food in the world.
Commencing in Middle California as
separate streams, in Northern California
1t becomes a flood flowing over and
completely manteling the smaller ine-
qualities, and flowing around the greater
inequalities of surface, while in North
ern Oregon and Tacoma it becomes an
absolutely universal food, beneath
which the whole original face of the
country with its hills and dales, noun
tains, and valleys, lies buried several
thousand feet. It covers the greater
portion of Northern California and
Northwestern Nevada, nearly the whole
Of Oregon, Tacoma, and Idaho, and runs
far into Montana on the East and Brit
ish Columbia on the North
This enormous matter evidently arose
through assures, and flowed until the
streams or masses met, forming an al
most continuous sheet. The Cascade
range of mountains seems to have been
q source of immense overflow.
The area covered by this overflow can
not be less than 100000 square miles,
with an average thickness of about 2, 600
feet, but having q thickness in some
places of $500 feet. The statement,
which seems an extraordinary one, is
sustained by the extensive observations
of Prof. LIE Contc. The Columbia
River cuts through the Cascade range
in gorge a hundred miles in length,
with perpendicular cliffs. The Cas-
cades of the river are at the axis of the
range, and the cliffs here are $500 to
$500 feet above the river surface, and
are composed of lava, tier upon tier,
from top to bottom. Considering sur
face erosion, 1000 feet is regarded as q
moderate estimate for the original thick
ness of the lava flood at this place.
But the entire thickness of the lava
has been cut through, and the surface
revealed on which the flood was origin
ally formed. Here, at the rivers sur
face, underlying the mountains of lava,
are remains of ancient forests and evil
dences of interesting geological changes.
There occurs at the rivers edge, and
about fifteen feet upward, layer of
course conglomerate; on this, q layer
which appears to have been dirt-bed,
Or playground surface. On this surface
were found two silicifed stumps, with
their roots spread out, one Of which was
two feet in diameter, the roots reaching
over an area twenty feet in diameter.
Trunks Of other trees were seen. Over
this was layer of stratified sandstone,
with beautiful impressions Of leaves OF
several kinds of forest trees. Upon this
lies about one hundred feet of con.
glomerate, resembling drift, in the bot
tom of which were found trunks and
branches of oaks and conifers. Upon
the conglomerate the lava lies in colum-
mar masses to height of $500 feet.
The geological age Of the wood and
leaf bearing stratum is believed to be
miocene, or middle tertiary, and, If so,
the lava flood began to occur during or
after the miocene.