WASHINGTON DEPARTMENT OF NATURAL RESOURCES
DIVISION OF GEOLOGY AND EARTH RESOURCES
PREPARED IN COOPERATION WlfH fHE
U.S. GEOLOGICAL SURVEY
PRELIMINARY SURFICIAL GEOLOGIC MAP of the MUKILTEO and EVERETT QUADRANGLES, SNOHOMISH COUNTY, WASHINGTON
Mostly sand ond grovel deposited by streams. Moy con-
tain some silt, cloy, and organic material
Mostly sand and gravel with some silt and cloy . Occurs
as alluvial fons at the foot of steep volley sides.
Processes that specifically deposited older alluvium
ore no longer active
Lorge slumps that occurred during the oblation of the
Puget Lobe of the Vashon ice sheet by lowering
of water- table level, Slides may have been
active since original movement; locks evidence
of recent movement
Vashon recessional outwosh
Light- brown loosely compacted sand and gravel . Dry
grovel seeks angle of repose of 35°; wet gravel
will stand in near-vertical cliff. Sorting varies;
part icle size varies from medium sand to cobbles.
Stones ore usually covered with o light-brown
dusty coating and ore well rounded from stream
transportation . Contains some ice contact deposits
Poorly sorted, nonstrotified lodgment till deposited as
ground moraine. Mixture of clay, silt, sand, peb-
bles, and cobbles with occas iona l large boulders.
Appears gray to blue on fresh surface; may weather
to brown or yel low, Extreme ly compact, will stand
in near- vertical cliffs; generally locks surficial
cracks or ioin ts . Stones are subongulor to rounded.
Some larger closts show striations and faceting.
Vertical faces sometimes spoil off in large blocks .
Some areas of Ovt ore covered by a thin veneer of
loose ly consolidated , nonsorted oblation till and(or)
Voshon advance autwash
Fresh, light- gray , stratified, compact sand and grovel.
Will stand in near- verHcal cliff. Sorting varies;
particle size varies from fine sand to coarse pebbles
Thinly bedded (from 2 to 6 inches), fresh, light- gray
sand layers. Particle size varies from medium to
coarse sand (with lO percent pebbles); small peb-
bles often occupy the base of each individual bed
or lens. Occasional lenses of coarse grovel occur.
Usua ll y sloughs ta angle of repose on exposed
Sil~, cloys, and pebbly glociolocustrine silts; deformed
by ice thrusting
Generally medium-bedded (2 to 4 feet) sand, silt, and
clay. Color varies from light brown to gray. Par-
ticle siz e varies from cloy to coarse sand with a
few lenses of small pebbles. Sorting is generally
good within each individual bed. Clay and silt
beds can be as thin as 2 inches. Nonglacial river
flood - plain deposits . May show tectonic deforma-
Double SluH Drift
Contains: (1) iron-oxide cemented grave l, consisting of
small to medium pebbles well cemented in a grit
matrix; (2) pebbly glociolacustrine silts; and (3)
massive si It and lesser beds of sand and grove l.
Well compacted and will stand in a near- vertica l
cliff. Pebbly sifts display des iccation crocks at
the surface . Moy show tecton ic deformation
Arti fi ci a 1 fill
0 w 0
u .., .~c'» r[
' ,, C='I \ r/3P 1 .,
J \ I ~~ _)/)? \ s:u; ~ >·>r ,'I
1L -,~1 r; , \_L.':i .··, (· •.
\..._ ."'-.:-l.,, , -r· 'I · 'b
1~----.;"~ '( --~ ~~'-,. 1 · :·"" ~ --.. '·
, :·\\\Js-\nl /v , ':' i. ; ~\ ~ ~ :.·· ,,.- ''
l~:' - ,,, .. _ r·]-h\Jri'i //
ro8eaco 'l'io ) ) . ••.. :
I ,I -~ 'r ,. f 1,··r· ( . \...\
~1-·H ~-\\c~Y+- +---~
' r. I ' ~. .. ~. . ' .
~1 Q vr
' ,_I ' .
I ' ' . . " \ \ , I
\ ' •
T • \ "'
24 \ . '/ · ..
• • ~ 530'
·-Q ., -
' .. · .. .
~ . ; . J
~ I 1
' . ~r ..
.. ...,-,'1 , .. . : ~ I ._ I
_'.. y· , ,'.- ,I
·.· ~ ,~
• • . . r
?1 . • ~ - ..
· i . Gvt i\
~. - I
. ai' ,,,
- " -,,
I ·' I ,'
"' . .,
1!: .. '
:'f i ,. '
"' 1! ' : :: i .,
:'ii/ ,, ' ... :u .. ., .
"' // f
/,!; , .. ,,, ...
; ! !