The Evening statesman. [volume] (Walla Walla, Wash.) 1903-1910, 1903-10-24
GEOLOGY OF STATE
OFFICIAL REPORT
The United States Geological Survey
Is About to Issue Valuable
Paper.

The United States Geological Sur
vey is about to issue professional pa
per No. 10, being contributions to the
geology of Washington, by Mr.. George
Otis Smith, who writes on the geolc-
gy and physigoraphy of central Wash
ington, and Mr.. Bailey Willis, who
writes on the photography and defor-
nation of the Wenatchee- Chelan dis
trict, Cascade range.
The paper may be said to consist
Of three principal parts. The first, to
which both writers contribute, is q
description Of the topographic fea-
lures Of the Wenatchee- Chelan dis
trict, the treatment being according
to localities, and the purpose being
to present the evidence of physio-
graphic features. The several stages
of mountain growth and sculpture
which have been distinguished are
discussed, each by itself This sec
ton may be read as a statement OF
history, descriptions, provided the
reader accepts the evidence previous.
ly offered. The third part is a discus
sion of the reformation which has re-
suited in the uplift of the Cascade
range, and is closed by a speculative
consideration of the nature and locus
of activity of stresses which have
produced it.
The description and analysis of the
topographic features result in distin-
gushing three principal stages of ply
sographic development. First there
is recognized an ancient pene- plain,
which was described by Russell as the
Cascade plateau, and which is here
called the Methow plain. Disregard
ing occasional monadnocks, it's posi-
ton is seen to coincide with the
SUBMITS of the mountains or to eX-
tend above them. A few remnants
are identified as corresponding close
ly to the actual plain surface, but in
general the evidence Of it's former eX-
istence is found in the uniformity of
attitudes of neighboring peaks. Dur
ing the next, the Entiat stage, topo~
graphic features reached mature de-
velOpment, and the Methow plain
Entiat valleys are observed to form
the upper part Of the cross sections
OF the existing much deeper canyons,
but they are not always present
Their absence is interpreted to indi-
cate the effects of consequent develop
ment of streams and stream capture
during the succeeding stage The
third, or twisp, stage was that during
which the deep canyons that now
characterize the landscape were de-
veloped. The typical twisp features
are the dominant and striking ones of
the region. The Chelan stage CORE
spends to that of the latest glacial
occupation.
The effects of reformation are in
vestigated by ascertaining the form
of the warped surface of the Methow
plain. It is concluded that the cascade
uplift is one of great breadth and fat
surface, and that the eastern and
western margins are characterized by
minor warnings, the axial trend of
which is from southeast to northwest,
whereas the trend of the major axis
of the Cascades is from north by east
to south by west. The theoretical
discussion of the stresses capable of
producing such a structure leads to
the inference that the actual deforma-
ton of the rock mass has taken place
through the development Of cleavage
structures and shear structures, and
that the stresses, acting probably be-
low 40 miles in depth. were such as
are effective beneath the superficial
outer crust.