AMETERS

2000

1500

1000

500

SEA LEVEL

500

1000

1500

2000

Trm Trl

Cle

Elu

m L

ake

Yak

ima

Riv

er

Big

Cre

ek

BlazedRidge

KesQ

Ked

KhbTbf

TnrWH

ITE

RIV

ER

FA

ULT

ZO

NE

TnrTnb

TnsTo

Lit

tle

Nac

hes

Riv

er

Tf

Cro

w C

reek

TeTfbTfTn Tn

Tta

TmKbg Easton

Ridge

TtTtTssp

Tss

Wes

t For

k T

eana

way

Riv

er

QQQG

reen

Riv

er

HuckleberryMountain

WH

ITE

RIV

ER

FA

ULT

ZO

NE

Whi

te R

iver

Che

nuis

Cre

ek

TfciTf

QTfcr

To

Tcr

Tfce

Tf Tfst

Tfst

To

To ToTeg Tf

TfTf

ToTo

TfrtTfrtTegTeg

Q

CougarMountain

Q Q

TfTfce

Cle

Elu

m R

iver

GoatMountain

Wap

tus

Riv

er

Coo

per

Riv

er

ST

RA

IGH

T C

RE

EK

FA

ULT

ZO

NE

RampartRidge

Coa

l Cre

ek

CascadeCrest

Han

sen

Cre

ek

Ced

ar R

iverGrass

Mountain

Whi

te R

iver

Sout

h P

rari

e C

reek

KJisTss

Q

TdrdTdv

TssTdgr

Tdv

TdgrTss

TdgrTss

TssKesKedKed

KesTnr

TstnTns

QTnbg

TnbgTnrTnbgTnmc

Tnmc TngTng TnmcTsgsTsgs

TegTf

To

Teg QToTf

TfrtTegTf

Tf

ToTfcr

TfTfcrTo

To

Tip

Tp

Teg To

Tfce Q

Gre

en R

iver

Gol

d C

reek

Tns

Q QQ

QQQQQ

Q

QQ Q

Q

BE

ND

IN

SE

CT

ION Box

RidgeA''

METERS2000

1500

1000

500

SEA LEVEL

500

1000

1500

2000

C'METERS2000

1500

1000

500

SEA LEVEL

500

1000

1500

2000

CMETERS

2000

1500

1000

500

SEA LEVEL

500

1000

1500

2000

500 meters=1640.4 feetUnconsolidated deposits, (Q) undifferentiated and exaggerated in thickness, small areas not shown

500 meters=1640.4 feetUnconsolidated deposits, (Q) undifferentiated and exaggerated in thickness, small areas not shown

500 meters=1640.4 feetUnconsolidated deposits, (Q) undifferentiated and exaggerated in thickness, small areas not shown

B'METERS2000

1500

1000

500

SEA LEVEL

500

1000

1500

2000

BMETERS

2000

1500

1000

500

SEA LEVEL

500

1000

1500

2000

A'

SE

CT

ION

B-B

'

20

20

20

40

30

30

m

Qa

Qb

Ql

Qmw

Qt

Qlh

Qu

Qag

Qvr

Qvi

Qvt

Qva

Qvu

Qpf

Qpfa

Qra

Qcc

Qcct

Tbd

Th

Tcp

TgnF

TgrF

Te

Tsgs

Tsgf

Tsgg

Tstn

Tsm

Tcr

Tip

Tit

Tiap

Tidp

Tf

Tfv

Tfb

Tfc

Tfci

Tfce

Tfrt

Tfst

Tfcr

Teg

Tdv

Tdgr

Tdrd

Tdb

Tdr

To

Tolk

Tv

Tdg

Tn

Tns

Tng

Tnb

Tnr

Tnbg

Tnmc

Tp

Tpr

Tpt

Tptm

Tmp

Trr

Tru

Trm

Trl

Tt

Tdg

Tss

Tsc

Tssp

Tsi

Tbf

Tbfb

Tta

Tm

TKwa

TKwv

TKwg

TKwu

TKev

TKem

pTqm

pTlm

pTla

pTlg

TKt

TKtu

Kt

Knp

Kes

Ked

Ktz

Khb

Kbg

KJim

KJid

KJia

KJis

LIST OF MAP UNITS(See pamphlet for complete map unit descriptions)

MASS WASTAGE AND ALLUVIAL DEPOSITS

Man-Modified land (Holocene)

Alluvium (Holocene and Pleistocene)

Bog deposits (Holocene and Pleistocene)

Landslide deposits (Holocene and Pleistocene)

Mass-wastage deposits (Holocene and Pleistocene)

Talus deposits (Holocene and Pleistocene)

Lahar deposits (Holocene and Pleistocene)

GLACIAL DRIFT AND RELATED DEPOSITS

Surficial deposits, undivided (Holocene and Pleistocene)

Alpine glacial deposits (Pleistocene)

Deposits of Vashon stade of Fraser glaciation of Armstrong and others (1965) of Cordilleran ice sheet (Pleistocene)ÑDivided into:

Recessional outwash deposits

Ice-contact deposits

Till

Advance outwash deposits

Vashon Drift, undivided

Glacial and nonglacial deposits of pre-Fraser glaciation age (Pleistocene)

Alpine glacial drift of pre-Fraser glaciation age (Pleistocene)

BEDROCK

Andesite of Mount Rainier (Pleistocene)

Basalt of Canyon Creek (Pleistocene)ÑLocally, includes:

Basaltic tuff and breccia

Basalt of Dalles Ridge (Pliocene)

Howson Andesite (Miocene)

Volcaniclastic rocks of Cooper Pass (Miocene)

Columbia River Basalt GroupÑDivided into:

Grande Ronde Basalt (Miocene)ÑDivided into:

Flows of normal magnetic polarity

Flows of reverse magnetic polarity

Ellensburg Formation (Miocene)

Rocks of Snoqualmie batholithÑDivided into:

Tonalite and granodiorite, southern phase (Miocene)

Fine-grained monzonite (Miocene)

Granodiorite and granite (Miocene)

Tonalite and granodiorite, northern phase (Miocene and Oligocene)

Mafic diorite and gabbro (Miocene and Oligocene)

Carbon River stock (Miocene)

Intrusive rocks (Miocene and Oligocene)ÑDivided into:

Pyroxene andesite porphyry

Tonalite

Altered porphyry

Dacite porphyry

Fifes Peak Formation (Miocene)ÑDivided into:

Volcaniclastic rocks

Andesite and basalt megabreccia

Crystal-lithic tuff

Rhyolite unit of Clear West PeakÑDivided into:

Intracaldera rhyolite

Extracaldera rhyolite tuff

Rhyodacite tuff

Sun Top unit

Chenuis Ridge unit

Volcanic rocks of Eagle Gorge (Miocene and Oligocene)

Volcanic rocks of Mount Daniel (Oligocene)ÑDivided into:

Andesite, dacite, and rhyolite volcanic rocks

Granophyre and rhyolite porphyry

Rhyodacite tuff

Breccia

Rhyolite

Ohanapecosh Formation (Oligocene)ÑLocally, includes:

Tuff member of Lake Keechelus

Volcanic rocks (Oligocene)

ROCKS WEST OF THE STRAIGHT CREEK FAULT

Diabase, gabbro, and basalt (Oligocene? and Eocene)

Green River-Cabin Creek Block

Naches Formation (early Oligocene? to middle Eocene)ÑDivided into:

Feldspathic sandstone and volcanic rocks (late and middle Eocene)

Rhyolite (late and middle Eocene)

Basalt (late and middle Eocene)

Guye Sedimentary Member (late and middle Eocene)

Mount Catherine Rhyolite Member (late and middle Eocene)

Glomeroporphyritic basalt (late and middle Eocene)

Puget GroupÑDivided into:

Renton Formation (late and middle Eocene)

Tukwila Formation (late and middle Eocene)

Tiger Mountain Formation (middle Eocene)

Volcanic rocks of Mount Persis (late? Eocene)

Raging River Formation (middle Eocene)

ROCKS EAST OF THE STRAIGHT CREEK FAULT

Teanaway River Block

Roslyn Formation (late and middle Eocene)ÑDivided into:

Upper member (late Eocene)

Middle member (late and middle Eocene)

Lower member (middle Eocene)

Teanaway Formation (middle Eocene)

Diabase, gabbro, and basalt (Eocene)

Swauk Formation (middle and early Eocene)ÑDivided into:

Sandstone

Conglomerate facies (middle and early Eocene)

Silver Pass Volcanic Member (early Eocene)

Ironstone (early Eocene)

Manastash River Block

Basalt of Frost Mountain (middle Eocene)—Locally divided into:

Basalt breccia and tuff

Taneum Formation (early Eocene)

Manastash Formation (early Eocene)

ROCKS SOUTHWEST OF DARRINGTON-DEVILS MOUNTAINFAULT ZONE

Rocks of the western mélange belt (middle Eocene and (or) Late Cretaceous)ÑDivided into:

Argillite and graywacke

Metavolcanic rocks

Metagabbro

Ultramafic rocks

Rocks of the eastern mélange belt (middle Eocene and (or) Late Cretaceous)ÑDivided into:

Chert, mafic metavolcanic rock, amphibolite, and marble

Marble

Quartz Mountain stock (pre-Tertiary)

Lookout Mountain Formation of Stout (1964) (pre-Tertiary)ÑDivided into:

Mica schist

Amphibolite and hornblende tonalite gneiss

Gabbro and metagabbro

ROCKS IN DARRINGTON-DEVILS MOUNTAIN FAULT ZONE

Tectonic complex of Stout (1964) (Tertiary and (or) Cretaceous)— Locallydivided into:

Ultramafic rocks

ROCKS NORTHEAST OF DARRINGTON-DEVILS MOUNTAIN

FAULT ZONE

Tonalite (Late Cretaceous)

Metavolcanic rocks of North Peak (Late Cretaceous)

Easton Metamorphic Suite (Early Cretaceous)ÑDivided into:

Shuksan Greenschist

Darrington Phyllite

Tectonic zone (Early Cretaceous)

Tonalite gneiss of Hicks Butte (Early Cretaceous)

Banded gneiss (Early Cretaceous)

Ingalls Tectonic Complex (Early Cretaceous or Late Jurassic)

Foliated and massive serpentinite and serpentinized meta-peridotite

Metabasalt, tuff, and breccia

Diabase and gabbro

Amphibolite

ContactÑDashed where inferred; dotted where concealed; queried where uncertain

High-angle FaultÑDashed where inferred; dotted where concealed. Bar and ball on

downthrown side. Arrows shown in cross section indicate direction of relative

movement

Major FoldsÑDotted where concealed. Arrowhead along axial trace shows

direction of plunge

Anticline

Syncline

Overturned Syncline

Strike and dip of bedding

Inclined

Inclined, top known

Overturned

Overturned, top known

Vertical

Vertical, top towards ball

Horizontal

Strike and dip of foliationÑIn igneous and metamorphic rocks

Inclined

Vertical

LineationÑShowing bearing and plunge. May be combined with other symbols

Zone of sheared rockÑSee description of sandstone unit of Swauk Formation (Tss)

Zone of foliated rockÑSee Description of foliated and massive serpentinite and

serpentinized metaperidotite (KJis) of Ingalls Tectonic Complex

Zone of silicified rhyolite

Crest of moraine

SpillwayÑArrow indicates direction of flow of drainage from recessional glacial

lakes. Number indicates present day altitude

Landslide arrowÑShows direction of movement of landslide

Location of dated sampleÑSee Table 1 in pamphlet

Teanway dike swarmÑArea underlain by dikes. Density of symbols indicate

estimated percent

mQa Qb

Ql Qmw

Qt Qlh

**Numbers in map-unit symbols represent specific recessional intervals 1-7 (1 being

the oldest) that are shown. No number indicates an indeterminate age in intervals 1-7.

Multiple numbers indicate an indeterminate age within the expressed range.

ROCKS WEST OF STRAIGHT CREEK FAULT

Green River-Cabin Creek Block

Tfv Tfc

TfciTfce

Tf

Tfcr

Tfb

TfrtTfst

Tn

Tnmc

Tnb

Tnbg

Tns

Tng

Tnb

Tnr

TnrTpr

Tpt

Tptm

TpTn

TbfbTbf

TKtu*

TKt*

TKwgTKwu

TKwv

TKwa

TKem

TKev

pTqm*

KtKnp

Kes Ked Ktz Khb Kbg

KJiaKJis

KJim

KJid

Tta

Tm

Tt

TsspTsc

Tss

Tsi

KJiaKJis

KJim

KJidKhb

Kes Ked

Knp

pTqm

TKwg

TKwa

TKev

TKem

pTlm pTla

Vashon

stade

Fraser

glaciation

Holocene

Pleistocene

QUATERNARY

Pleistocene

Miocene

QUATERNARY

Oligocene

TERTIARY

Pliocene

Early

Oligocene(?)

Middle

Eocene

Late Eocene

Early Eocene

Oligocene(?)

Eocene

TERTIARY

Middle

Eocene and

(or) Late

Cretaceous

Eoceneand (or)Cretaceous

Late

Cretaceous

Early

Cretaceous

EarlyCretaceousor LateJurassic

Late Jurassic

Pre-LateJurassic

EarlyJurassic

JURASSIC

CRETACEOUS

OR JURASSIC

ROCKS EAST OF STRAIGHT CREEK FAULT

TERTIARY AND

(OR) CRETACEOUS

CRETACEOUS

PERMAIN

TO

DEVONIAN

Teanaway River Block Manastash River Block

ROCKS SOUTHWEST OF

DARRINGTON-DEVILS MOUNTAIN

FAULT ZONE

ROCKS IN

DARRINGTON-DEVILS MOUNTAIN

FAULT ZONE

ROCKS NORTHEAST OFDARRINGTON-DEVILSMOUNTAIN FAULT ZONE

BEDROCK

Tdgr

Tdv

Tdrd

Tdb

153

160

Middle

Jurassic

95

84

52

47

40

37

36

28

25

19

21

20

12

6

52.41.6

0.70

0.55

0.01

MASS WASTAGE AND ALLUVIAL DEPOSITS GLACIAL DRIFT AND RELATED DEPOSITS

Unconformity

Uncomformity

Qag

Qvr** Qvi** Qvt Qva Qvu

Qpf Qpfa

Qu

QraQccQcct

Tbd

Th

Tcr Tsgs Tsgf

Tsgg

Teg

Tstn Tsm

TvTo

Tcp

TeTgn2

Tgr2

Tip Tit

Tidp

TiapTdr

Trl

Trm

Tru

Tdg

Trr

Tmp

Tdg

pTlg*

pTla*pTlm*

Tolk

CORRELATION OF MAP UNITS[*See Description of Map Units in pamphlet for specific unit age assignment]

Note: For m�lange and metamorphic units, position of boxes with solid boun-

daries indicates age of assemblage or metamorphism, respectively; position

of boxes with dashed boundaries indicates age of protolith

Approximate age (Ma)(From time scale of Cowieand Bassett, 1989 and

Berggren and others, 1985)

ST

RA

IGH

TC

RE

EK

FA

ULT

DDMFZ

WHITE

RIVER

FAULT

ZONE

MANASTASHRIVER BLOCK

Figure 2. Generalized geologic map of Snoqualmie Pass quadrangle, Washington. DDMFZ, Darrington-Devils Mountain Fault Zone.

0

0 5 10 m

5 10 km

GREEN RIVER -- CABIN CREEK BLOCK

KeechelusLake

KachessLake

SnoqualmiePass

Howard HansenReservoir

GraniteMtn

NorthBend

Chester MorseLake

122°47°30'

121°

Cle ElumLake

TEANAWAY RIVERBLOCK

Roslyn

Enumclaw

SNOQUALMIEBATHOLITH

Clear WestPeak

HicksButte

CARBON RIVERSTOCK

Kachess Ridge

47°00'

Huckelberry Mountain

NachesPass

Unconsolidated deposits

(includes some deposits of

the Cascade Arc)

Marine sandstone and shale

(Raging River Formation)

Basalt and andesite flows and

breccia (Teanaway Formation, and

basalt of Frost Mtn)

Terrane units

ROCKS SOUTHWEST

OF DARRINGTON-

DEVILS MTN

FAULT ZONE

ROCKS NORTHEAST

OF DARRINGTON-

DEVILS MTN

FAULT ZONE

ROCKS IN

DARRINGTON-DEVILS

MTN FAULT ZONE

(DDMFZ)

Rocks of western and eastern

m�lange belts (includes

Lookout Mtn Formation of

Stout, 1964, Quartz Mtn stock)

Serpentinite and argillite

matrix tectonic breccia

(tectonic complex of

Stout, 1964)

Easton Metamorphic Suite1

(includes tonalite gneiss of

Hicks Butte, tectonic zone)

Ultramafic rocks1

(Ingalls Tectonic Complex)

Metamorphic rocks of

North Peak1

Basalt, andesite,

and minor dacite

Rocks of Cascade Arc

Columbia River

Basalt Group

Andesite basalt, rhyolite, and

dacite (Fifes Peak Formation)

Tonalite to granite

(includes rocks of

Snoqualmie batholith,

Carbon River stock)

Andesite, basalt, and dacite (includes

Ohanapecosh Formation,

volcanic rocks of Mt Daniel)

ROCKS WEST OF

STRAIGHT CREEK FAULT

Green River-Cabin Creek Block

Interbedded fluviatile sandstone

and volcanic rocks (includes

Pugit Group, Naches Formation)

Fluviatile sandstone, shale, and

coal (Roslyn Formation)

ROCKS EAST OF

STRAIGHT CREEK FAULT

Teanaway and Manastash River Blocks

Fluviatile sandstone and dacitic volcanicrocks (Includes Swauk, Manastash,

and Taneum Formations)

Unconformity

QUATERNARY

Pliocene

and

Miocene

Miocene

Oligocene

Oligocene(?)

Eocene

TERTIA

RY

MiddleEocene

and(or)Late

Cretaceous

Early

Cretaceous

Early

Cretaceousor

LateJurassic

TERTIA

RY

AND(O

R)

CRETACEOUS

CRETA-

CEOUS

CRETA-

CEOUSOR

JURASSIC

PERMIA

NTO

DEVONIA

N

ContactÑDotted where concealed

FaultÑDotted where concealed

Structural block boundary and fault

SynclineÑDotted where concealed.

Arrow indicates plunge

AnticlineÑDotted where concealed.

Arrow indicates plunge

EXPLANATION

1Unit shown by protolithic age

Area of Figure 2

OLYMPIC

WALLOWA

LINEAMENT

Seattle

CANADA

UNITED STATES

British Columbia

Washington

DARRINGTON-DEVILSM

TN

FA

UL

TZ

ON

E

WESTERNAND

EASTERN

MÉ

LAN

GE

BE

LT

Chelan

Wenatchee

WHITERIVER

FAULTSNOQUALMIE

PASS WENATCHEE

CHELAN

SKYKOMISHRIVER

HELENA-HAYSTACKMÉLANGE

SaukR

ManastashRidgearea

Mt Baker

Mt Shuksan

GlacierPeak

KyesPeak

HaystackMtn

Mt Daniel

Mt Stuart

Mt Rainier

Rimrock Lake

inlier

NORTHWESTCASCADESYSTEM

Area of Figure 1

WASHINGTON

Cascade

Cre

st

OLYMPIC

MOUNTAINS

SnoqualmiePass

SanJuan

Islands

Skagit

River

NORTHWEST

CASCADE

SYSTEM

JUAN DE FUCASTRAIT OF

PU

GE

TLO

WLA

ND

TongaFm

I-90

Bellingham

MountMisch

Darrington

Yakima

Rive r

FA

ULT

EN

TIA

T

0 60 KILOMETERS

60 MILES0

TERTIARY SEDIMENTARYAND

VOLCANICROCKS

CO

LUM

BIA

RIV

ER

IslandVancouver

NORTH

CASCADECRYSTALLNE

CORE

ST

RA

IGH

TC

RE

EK

FA

ULT

Figure 1. Regional overview of geologic setting for Snoqualmie Pass quadrangle, Washington. Arc plutons are

not shown. Wenatchee 1¡ by 2¡ quadrangle is composed of the Skykomish River, Chelan, Snoqualmie Pass, and

Wenatchee 1:000,000-scale quadrangles (shown in magenta).

123° 122° 121° 120°

49°

48°

47°

ALPINE LAKESWILDERNESSAREA

ALPINE LAKES

WILDERNESSAREA

NORSE PEAK

WILDERNESSAREA

CLEARWATER

WILDERNESS

AREA

A

B'

A"

B C

C'

A'

Ql

Qag

Tf

Teg

To

Qu

QagTeg

Tidp Qag

Ql

TipTo

Qa

Tiap

Tip

Tip

Teg

Ql

Ql

Tpt

KJis

KJis

Qvt

Qa

Trr

Tss

QvtQvt

Tss

QaTstn

TKwa QagTstn

QaQvt

Qag

Tdrd

Qa

Trr

Qa

Tdgr

Qvt

Tnbg Kt

TvTKwa

Qa

Tdr

Qvt

Qva Qa

Tv

Ql

QaKed

Tns

Qa

KJim

Qa

QaQvrQa

Qa Tstn

Ked

To

TKwaTKwgQvt

TnrQt

QaQvr

Tns

QvtTpt

Qvt

Qva

Qva

Qag

Tsm

QvtTsgs

Qvr

QagQa

Tng Tns

Qa

Qa

Qvt

Qvr

Tp

Qag

Tng

Qvi

Qa

Tp

Teg

QaTitTp

Tp

Qvt

Qvt

Qu

Tt

Tp

Qvt

TsgsQa

TpQa

Qvr

QuQag

To

TsmTp

Tn

Qb

Qa

QuTegQaQag

Qa Qb

Qmw

Tt

Qa

Qa

TnTidpQagTn

QaTnr

Qa

Tns

Tt

QbTp

Qa

Qag

Teg

Teg

Tf

Teg

TpQa

Tnr Qa

TfQag

Tfrt Qa

Tnr

Tru

Tnr

Ql

QvtTo

To

Tp

Qvu

Qmw

Qlh

m

QlQa

Qa

Qa

Tnr KesTf

Qag

TnQlTeg

Qvi

Tf

Qa

Qa

Tn

QviQag

Tit

Tit

Qlh

Tf Tf

Tns

Tf

Qa

Ked

Tm

QvrQa

Tf

Qa

To

Tidp

Ql

Qlh

Qlh Qvt

Tit

Tf

Tf Tfst

Qa Qlh

QaTiapQlh

Qvu

Qlh

Tm

To

Ked

Qa

Tf

Tfst

Qlh

Qvu

Tf

Tnr

Tta

Qa

QlTnr

Tm

Tiap

Qcc

Ql

Qa

Tf

Qlh

Ql

Tfce

Qvu TfstTo TiapTo

To

Tf

QaTit

Tbd

Tip

TmQcct

Tip

Tnr

QlTfv

Tnb

pTla

pTlg

pTlg

Tfst

QlQag

QlQag

Qa

Tf

Tip

TnsQl

Qlh

TfTip

QagQl

TfTfTip

Tfst

Ql

QlQpfa

TnsQl

Qag

QlQa

Qpfa

Qt

TgnF

TnsTgnF

Qra

Ql

Tfst

Ql

Tf

Tfci

TfbQa

To

Qa

Tf

Ql Tn

Tf

Qa

QaTnbTfcr Tit

TptQvt

Tp

Tpt

Tpr

Tpt

Tp

Qvr

Ql

Tmp

Tpr

Tpt

Tpt

Tp

Tptm

TKwg

TKwa

Qa

TKwg

TKwg

Tsm

Tsgs

TKwa

Tv

Qmw

Tsm

Tv

Qag

Tsgg

Qa

Tng

Tsgg

TKev

Tnmc

TKem

Tv

Tstn

Qag

Ql

Tn

Qag

Tv

Qt

Qt

Qa

Tstn

Ql

Ked

Tnr

Tcp

Qag

Tdrd

Ql

Tdv

Tit

Qa

Qag

Qa

Qa

Qa

Ql

Qag

Tss

Qt

Tdgr

Qa

Tss

Ked

Kes

Tns

Qa

Qt

To

Tolk

Tnbg

Tng

Tnmc

Qag

To

QaTsm

Tsgs

Ql

Qa

TKwg

To Tit

Tip

Qvt

Qpf

Qvt

Tp

Tdg

Tp

Tdg

Ql

Tp

To

Qu

Qag

Teg

Tp

Qag

Qmw

Ql Ql

Tidp

QagQag

Tolk

Tssp

Tssp

To

Tf

Qa

Qvr

Ql

Qag Tfrt

Teg

Qpfa

Qag Tp

To

Tfcr

Tcr

Qt

Tfci

Qt

Tfci

Qag

Tit

Qpfa

Qmw

Tfst

Qlh

To

Ql

Qt

Tip

Tfv

Ql

Ql

Tnr

Tnb

pTlm

TKt

Tbfb

Ql

Tbfb

Tbf

Tta

Tdg

pTla

Khb

Qag

Qa

Qa

Qag

Tnb

Tn

Tbf

Tit

Ql

Ql

Qag

Tdg

Qa

Ql

Ql

Tidp

Qa

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U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Geology mapped by V.A. Frizzell, Jr., R.W. Tabor, and R.B. Waitt, 1975-82; S. Allshouse and E.A. Rodriquez, 1975; J.F. Coburn and R. Tal, 1976; W. Gaum, M. Goddard, and K.L. Marcus, 1977; E.L. Mathieson and N.B. Shew, 1978; D.B. Booth, 1978-82; S.F. Connally, S.L. Sandberg, F. Beall, F.C. Moser, and S. Cook, 1981; C. Eddy, K.M. Ort, and T. Schirmer, 1982

Digital database by R.W. Tabor

Edited by Dale Russell, Julia Thomas, and Jan Zigler; digital cartography by Kathryn Nimz with assistance from Taryn A. Lindquist, Sara Boore, Susan Mayfield, and Kevin Ghequiere

Manuscript approved for publication January 23, 1995

Base from U.S. Geological Survey, 1975

Transverse Mercator projection

SCALE 1:100 000

1 10 4

5000 100000 15000 20000 25000 FEET

1 0 3 5 7 8 10 KILOMETERS

5 MILES

1 2 4 6 9

2 3

5000

CONTOUR INTERVAL 50 METERSNATIONAL GEODETIC VERTICAL DATUM OF 1929

WASHINGTON

AREA OF QUADRANGLE

GEOLOGIC MAP OF THE SNOQUALMIE PASS 30×60 MINUTE QUADRANGLE, WASHINGTONBy

R.W. Tabor, V.A. Frizzell, Jr., D.B. Booth, and R.B. Waitt2000

GEOLOGIC INVESTIGATIONS SERIES

MAP IÐ2538

Pamphlet accompanies map

APPROXIMATE MEANDECLINATION, 2000

MA

GN

ET

IC

NO

RT

H

18 / °12

TR

UE

N

OR

TH

47°00'

47°30'122°00'

45' 121°00'47°30'

15'

47°00'121°00'15'30'122°00'

15'

30' 15'

45'

WASHINGTON

For sale by U.S. Geological Survey, Information Services, Box 25286,Federal Center, Denver, CO 80225, or call 1–888–ASK–USGS

Available on World Wide Web at http://geopubs.wr.usgs.gov/i-map/i2538Printed on recycled paper

INTERIOR—GEOLOGICAL SURVEY, RESTON, VA—2000

80-85% 5-10%