U.S. DEPARTMENT OF THE INTERIOR GEOLOGIC INVESTIGATIONS SERIES U.S. GEOLOGICAL SURVEY MAP IÐ2538 Pamphlet accompanies map 122°00' 121°00' 47°30' 45' 30' 15' 47°30' Qvt CORRELATION OF MAP UNITS Tpt Trr Qvt TKwa Qag LIST OF MAP UNITS Qvr TKwv Tstn Qag [*See Description of Map Units in pamphlet for specific unit age assignment] 4-6 Tstn Tstn Tstn Tss A" (See pamphlet for complete map unit descriptions) Tpt Qvt TKwa KJis Qa TKwg Qvr Qa Qag Qa Note: For mlange and metamorphic units, position of boxes with solid boun- Tdg Qvt 1 Qa Tss Qag daries indicates age of assemblage or metamorphism, respectively; position Qvr TKwa 3-6 Ql of boxes with dashed boundaries indicates age of protolith Qvt Qa MASS WASTAGE AND ALLUVIAL DEPOSITS ROCKS EAST OF THE STRAIGHT CREEK FAULT Tdrd Qa Teanaway River Block Tptm Trr Tsm Tn Approximate age (Ma) m Man-Modified land (Holocene) Qvt Qvr Tsgg Qa Tp 3-6 Tdrd (From time scale of Cowie Tnbg Kt MASS WASTAGE AND ALLUVIAL DEPOSITS GLACIAL DRIFT AND RELATED DEPOSITS Roslyn Formation (late and middle Eocene)ÑDivided into: Tnb Tdv and Bassett, 1989 and Alluvium (Holocene and Pleistocene) Tp Tmp TKwa Tv Ql KJia Qa Qa Berggren and others, 1985) Tv Tru Upper member (late Eocene) Qvt Tdr Qb Bog deposits (Holocene and Pleistocene) Tp Tptm TKwu Tsgs Tng Tit Tpr Ql Qt Tdgr m Holocene Trm Middle member (late and middle Eocene) Qva Qlh TKem Qa KJid Qa Qb Qt Ql Landslide deposits (Holocene and Pleistocene) Ql Qt 0.01 Qvt Trl Lower member (middle Eocene) Tit TKwg Qvr1 TKev Qvi3 Ked Tss Qa Qmw Mass-wastage deposits (Holocene and Pleistocene) Tit KJim Ql Qmw Qu QUATERNARY Tptm Tstn Kes Qvr** Qvi** Qvt Qva Qvu Tpt Tnmc Tt Teanaway Formation (middle Eocene) stade Pleistocene Qpf Fraser Qa Vashon Tpt Qa Tnmc Tstn Qag glaciation Qt Talus deposits (Holocene and Pleistocene) Qa Tdgr Qvr Tsm ALPINE LAKES WILDERNESS AREA Qpf Qpfa Tdg Diabase, gabbro, and basalt (Eocene) TKev Qag Qa Qa Ql Qvt Qvr Qvi Qa Tstn Qlh Lahar deposits (Holocene and Pleistocene) 7 Tpt 3 Tv ÑDivided into: Tv Qa Swauk Formation (middle and early Eocene) Tpt Tns **Numbers in map-unit symbols represent specific recessional intervals 1-7 (1 being Ql TKwa TKwg Qt Tss the oldest) that are shown. No number indicates an indeterminate age in intervals 1-7. GLACIAL DRIFT AND RELATED DEPOSITS Tss Sandstone TKwg Tv Tsgg Tnr Ked KJis Qvt Tv Multiple numbers indicate an indeterminate age within the expressed range. Tpr TKem Tns Qvr Qu Surficial deposits, undivided (Holocene and Pleistocene) Qvr1 Qt Tsc Conglomerate facies (middle and early Eocene) Qvr1 Qvr1 Ked Qag BEDROCK Qvi Tnr 1-2 Tsgf Qvt Qvi Qa Qag Alpine glacial deposits (Pleistocene) Tssp Silver Pass Volcanic Member (early Eocene) Qvr 5 Qa TKwg Tpt Tpt Qvr1 Tnmc Tsc Qvr Qag Tcp Qra Deposits of Vashon stade of Fraser glaciation of Armstrong and others (1965) of Ironstone (early Eocene) Qa Qvr Tsi 1 Qmw ALPINE LAKES Qcc ÑDivided into: Tp Qa 0.55 Qcct Cordilleran ice sheet (Pleistocene) WILDERNESS AREA Qag Pleistocene QUATERNARY Manastash River Block Qvt To Tsm Tns 0.70 Qvr Recessional outwash deposits Qb Qvr1 Qag Tnr Tbf Basalt of Frost Mountain (middle Eocene)—Locally divided into: Qa Tns Tss 1.6 Qva Qa Qag Ql Pliocene Qvi Ice-contact deposits Qvr Qa 2.4 Tbd Tsgs 1 Qt Tbfb Basalt breccia and tuff Qvt Qva Qvr Qvi 3-4 5 Qvt Till Qa Qpf Tsm Th Qa To Tta Taneum Formation (early Eocene) Qvr5 6 Qvr6 Tip Qva Advance outwash deposits Tnbg Qa Tcp Qvi Tit Qvr 1-2 Tm Manastash Formation (early Eocene) 5 12 Qvu Vashon Drift, undivided Qvr 2-3 Tng Qt Qvt Tng Tns Tss Tgn2 Qag Qag Te ROCKS SOUTHWEST OF DARRINGTON-DEVILS MOUNTAIN Tsgs Qa Qpf Glacial and nonglacial deposits of pre-Fraser glaciation age (Pleistocene) FAULT ZONE Qvr Ked Tgr2 Qvi5 Tit Qt Miocene Qvt To Tnmc Qpfa Alpine glacial drift of pre-Fraser glaciation age (Pleistocene) Rocks of the western mélange belt (middle Eocene and (or) Late Tp Qa Tss ÑDivided into: Qa Tng Tsgs Tsgf Cretaceous) Teg Qt Qa To 19 Tcr Qa Qag Th BEDROCK TKwa Argillite and graywacke A' Tit Tsgg TERTIARY Tdg Qag 20 Tit Knp Qa Tfv Tfb Qra Andesite of Mount Rainier (Pleistocene) Qvr1 To Qa Kes Tfc TKwv Metavolcanic rocks Tp Tolk Tolk Tip Tit Ql Tfci Tf Tdgr Tfrt ÑLocally, includes: Tp Tdg Qcc Basalt of Canyon Creek (Pleistocene) TKwg Tp Qu 21 Tfce Tfst Metagabbro Qvu Qvi Tfcr Tns Tidp Tp Tsgs Qcct Basaltic tuff and breccia Qa Ultramafic rocks Tstn Tsm TKwu Ql Ql Tns Th 25 Tdgr Qvt To Teg Qu Tiap Tbd Basalt of Dalles Ridge (Pliocene) Qvr1 To Teg Tdv Tdr Rocks of the eastern mélange belt (middle Eocene and (or) Late Qvt Tp Qvt Ql To To Qag Cretaceous)ÑDivided into: Qvr Ked Tdrd 4 Qa Qu Tsm Oligocene Th Howson Andesite (Miocene) Tit Tnr Tp Tf Tp TKev Chert, mafic metavolcanic rock, amphibolite, and marble Qb Qvr Tdb 2 Tp 28 Tcp Volcaniclastic rocks of Cooper Pass (Miocene) Qag To Tolk Tv TKem Marble Qvr Qvr Qvi3-4 2 2 ÑDivided into: Tp Qu Qmw Qag C' Columbia River Basalt Group Qa Teg Qag 36 pTqm Quartz Mountain stock (pre-Tertiary) Qvr Qa Tt ÑDivided into: Qvr 3 Qag Qag Grande Ronde Basalt (Miocene) Qa Qag Qb Tssp Qvi Qu Tit Unconformity ÑDivided into: Tdg 1-2 Teg Tidp TgnF Flows of normal magnetic polarity Lookout Mountain Formation of Stout (1964) (pre-Tertiary) Qvr2 Teg Tidp Qvr4 Qa Tp ROCKS WEST OF STRAIGHT CREEK FAULT ROCKS EAST OF STRAIGHT CREEK FAULT pTlm Mica schist Tssp TgrF Flows of reverse magnetic polarity Qag Qvt B' Teg Kes pTla Amphibolite and hornblende tonalite gneiss Tidp Tn Tn Qmw Qag Green River-Cabin Creek Block Teanaway River Block Manastash River Block Te Ellensburg Formation (Miocene) Qvi Qvr Tdg Tnr 3-4 2 Tnr Early pTlg Gabbro and metagabbro Qa Oligocene(?) ÑDivided into: Qa Rocks of Snoqualmie batholith Qa Qvi1 To Tf Tt Oligocene(?) Qvr4 Tn Tn Tns Trl 37 Tsgs Tonalite and granodiorite, southern phase (Miocene) ROCKS IN DARRINGTON-DEVILS MOUNTAIN FAULT ZONE Qvr2 Qag Tdg Qvr1-2 Teg Tidp Tng Tnb Tnr Tn Tpr Late Eocene TKt Tectonic complex of Stout (1964) (Tertiary and (or) Cretaceous)— Locally Qb Tt Tmp Tru Tsgf Fine-grained monzonite (Miocene) Tp Tp Qvr divided into: Qvr4 Tiap Qvr Trm Tnbg Tn 1 Teg Qag 40 Tdg Tp Trm Tsgg Granodiorite and granite (Miocene) Ultramafic rocks Qvr Tpt TKtu 1-2 Ql Ql Qa Tnmc Trl Qa TERTIARY Tstn Tonalite and granodiorite, northern phase (Miocene and Oligocene) ROCKS NORTHEAST OF DARRINGTON-DEVILS MOUNTAIN Tp Teg Tf Tns Tnr Middle Eocene Tfrt Tnr Qa FAULT ZONE Qvt Qa Tptm Eocene Tsm Mafic diorite and gabbro (Miocene and Oligocene) Qvr Tnr Trm Tnb Tdg Tf Tt Tbfb Kt Tonalite (Late Cretaceous) To Tbf 15' Tdg To Tip Ql Ql 47 Tcr Carbon River stock (Miocene) Tru 15' To Knp Metavolcanic rocks of North Peak (Late Cretaceous) Tf Tip Trr Qvt Qvr3 m 52 Intrusive rocks (Miocene and Oligocene)ÑDivided into: Tip To Qag Qa Qag Qmw Tsc Tp Teg Tfrt Tssp Tta ÑDivided into: Tn Tns Early Eocene Tip Pyroxene andesite porphyry Easton Metamorphic Suite (Early Cretaceous) Qa Tss Tm Kes Shuksan Greenschist Ql Tip Tf Qa Tit Tonalite Qvr Tiap Ql Tnr Kes Qa Ked Darrington Phyllite Qvu Uncomformity Tsi To Tnr Tiap Altered porphyry Qa Khs Ktz Tectonic zone (Early Cretaceous) Tip Tn Qag ROCKS SOUTHWEST OF ROCKS IN ROCKS NORTHEAST OF Ql Teg Qa Tidp Dacite porphyry Teg DARRINGTON-DEVILS MOUNTAIN DARRINGTON-DEVILS MOUNTAIN DARRINGTON-DEVILS Qvi Qa Qa MOUNTAIN FAULT ZONE Khb Tonalite gneiss of Hicks Butte (Early Cretaceous) Qvi 1 FAULT ZONE FAULT ZONE Tf Fifes Peak Formation (Miocene)ÑDivided into: Qag Kbg Banded gneiss (Early Cretaceous) Tf Tit Qvi 1 Qag Qag Tfv Volcaniclastic rocks Tit Teg Qvi Ql Tdg Ql Qa TKt* Middle Ingalls Tectonic Complex (Early Cretaceous or Late Jurassic) Qlh Qag Eocene Qvr Teg Qa TKtu* Tfb Andesite and basalt megabreccia 1 Eocene and and (or) TERTIARY AND KJis Foliated and massive serpentinite and serpentinized meta-peridotite Qag Ql TKwv (or) Late Tf Kes Cretaceous (OR) CRETACEOUS Tit TKem Crystal-lithic tuff Tn Cretaceous Tfc KJim Metabasalt, tuff, and breccia Teg Tidp Ql TKwg TKwa TKev TKwu Rhyolite unit of Clear West PeakÑDivided into: Tf Tf KJid Diabase and gabbro Ql Ql pTqm* Tfci Intracaldera rhyolite Tit Tnr Tn Ked Tiap Tn Kt KJia To Ql Qa Amphibolite Tf Tf pTlm* pTla* Knp Late Tfce Extracaldera rhyolite tuff Qvr 84 Cretaceous Ql Qa Qa To CRETACEOUS Tf pTlg* Tfrt Rhyodacite tuff Qvr Tv 6 Ked Qag 95 ÑDashed where inferred; dotted where concealed; queried where uncertain Khb Early Contact Qa Qlh Tfce Tidp Tidp Tta Kes Ked Ktz Khb Kbg Cretaceous Tfst Sun Top unit Tf Tip Qmw Kbg High-angle FaultÑDashed where inferred; dotted where concealed. Bar and ball on Qlh Early Qvr1 Qvt KJim Tfcr Chenuis Ridge unit downthrown side. Arrows shown in cross section indicate direction of relative Tn Ktz Qa Cretaceous CRETACEOUS movement Ql Qa Qlh Tfst Tit Tm KJia KJid or Late Tf OR JURASSIC Teg Volcanic rocks of Eagle Gorge (Miocene and Oligocene) Qlh Qa KJis Tbf Jurassic Qvr Tiap Qa Tnr TKwa Major FoldsÑDotted where concealed. Arrowhead along axial trace shows 1 Qlh Ql Qlh Qmw Volcanic rocks of Mount Daniel (Oligocene)ÑDivided into: direction of plunge Qlh To Qa Tbf Kes Tdv Andesite, dacite, and rhyolite volcanic rocks Anticline Tf Tn Tnb Ked KJim Tf TKtu Tdgr Granophyre and rhyolite porphyry Tfst Khb Khb Late Jurassic Syncline To Tdg Tm Ktz 153 pTqm KJia KJid Qlh KJis Tdrd Rhyodacite tuff Tiap Overturned Syncline Qvu Qvu Tbfb Qa 160 TKwg Tm Pre-Late JURASSIC Tdb Breccia Middle Strike and dip of bedding Tfce Jurassic To To Tnr Jurassic Tf Ql TKtu TKev pTlm pTla 20 Tdg pTla Tta Inclined Ql Qa Tbf Tdr Rhyolite Qa Qa Qa Tip Qu Tfce Early 20 Qag Tf Qlh Tf Qa ÑLocally, includes: Inclined, top known Qa Tnr TKt Tta To Ohanapecosh Formation (Oligocene) Qvu To Tiap Tnb Kes Ked Jurassic Tfst Ql Tdg Tp To 30 Qcc Ql Overturned Tit Tfst Qa Tolk Tuff member of Lake Keechelus PERMAIN Qa Tbfb TKem 30 To TO Overturned, top known Ql Tip Tv Volcanic rocks (Oligocene) Tip Qpfa Tdg pTlm DEVONIAN To Knp Vertical Tbd Tns ROCKS WEST OF THE STRAIGHT CREEK FAULT Tit Tfv Ql Tbfb Qcct Tm Tip Tdg Diabase, gabbro, and basalt (Oligocene? and Eocene) Vertical, top towards ball Qa Ql Qmw pTlg Tf Qag ° Green River-Cabin Creek Block Tnr 123° 122° 121° 120 Horizontal Qlh Ql Tip Tbf Qag Qag CANADA British Columbia Tn Naches Formation (early Oligocene? to middle Eocene)ÑDivided into: Tip 49° Strike and dip of foliationÑIn igneous and metamorphic rocks Tfst Tf Qa Ql Tnr pTla Washington Tfci UNITED STATES 20 To Ql Tns Tdg CLEARWATER Tf STRAIGHT Tns Feldspathic sandstone and volcanic rocks (late and middle Eocene) Inclined Qlh Qag Ql WILDERNESS Tip Tit Tf Tf Tf WEST Mt Shuksan AREA To Tbf NORTH Tnr Rhyolite (late and middle Eocene) Vertical Tf Qa Qa Qa pTlg Bellingham Tfcr NORSE PEAK Tnb Isl Tfst and Tp Qpfa Ql Tnb Qag n s CASCADE Mt Baker 40 Tip Ql WILDERNESS AREA ua M ÑShowing bearing and plunge. May be combined with other symbols Tf Ql J er Tnb Basalt (late and middle Eocene) Lineation Tfv Qa Qa San SYSTE v t
i s Ql Tta R WASHINGTON Tit Ql Qa pTqm re Tns TKt Haystack C ÑSee description of sandstone unit of Swauk Formation ( ) TgrF Ska Tng Guye Sedimentary Member (late and middle Eocene) Zone of sheared rock Tss Mtn git CREEK Ql Area of Figure 1 Qag TgrF ascade Qt Qag Vancouver C Island Tnmc Mount Catherine Rhyolite Member (late and middle Eocene) Zone of foliated rockÑSee Description of foliated and massive serpentinite and A To Darrington NOR HCATH serpentinized metaperidotite (KJis) of Ingalls Tectonic Complex Tnr S
Tfci a
Te Tnr Ked u Tnbg Glomeroporphyritic basalt (late and middle Eocene)
Tns DA k RRI Mount
Qt Tns NG R Zone of silicified rhyolite STRAIT OF TO Misch SCADE Ql Tfcr Qa Qa Qpfa Tfst Qt N- Qa Ql TgnF J DE Tp Puget GroupÑDivided into: UAN DE FUCA HELENA- V Glacier Qpfa Tfst W IL Qpfa F Qt Qa HAYSTACK ES S ENTIAT CRYSTALLNE A Peak Qmw To TE Crest of moraine R U Qt Ql Ql MÉLANGE N M Qt T L Tpr Renton Formation (late and middle Eocene) Ql A T Qag N N R Tfci Qmw Tip Ql D E Qa V ÑArrow indicates direction of flow of drainage from recessional glacial Qlh Ql E I Spillway Tit Qa ° OLY D A R F 48 N S CORE Tpt Tukwila Formation (late and middle Eocene) lakes. Number indicates present day altitude T A Ql M A E Tcr L U FAULT To TgnF PIC R Kyes L W N Ql T Peak To O Chelan Tiger Mountain Formation (middle Eocene) Tn M Tptm Qra Qa L Landslide arrowÑShows direction of movement of landslide Tfst Tfb TgnF É Qa L Tp Z Qag Qa Tf OLYMPIC A Ql Tf Tns Seattle O Tonga Ql N Qa N Tmp Volcanic rocks of Mount Persis (late? Eocene) Tf G Fm A ÑSee Table 1 in pamphlet E I Location of dated sample Tf Tit Tnb E ° Qa Tfcr Tit Ql 47°00' B 47 00' B M
E ° ° U 122 00' 45' 30' 15' 121 00' MOUNTAINS L Trr Raging River Formation (middle Eocene) B INTERIOR—GEOLOGICAL SURVEY, RESTON, VA—2000 L ÑArea underlain by dikes. Density of symbols indicate C T Teanway dike swarm Mt Daniel O SKYKOMISH C estimated percent RIVER 80-85% 5-10% Mt Stuart CHELAN Base from U.S. Geological Survey, 1975 18 1/ ° SCALE 1:100 000 Geology mapped by V.A. Frizzell, Jr., R.W. Tabor, and R.B. Waitt, 1975-82; Snoqualmie 2 T 1 01 2 346 5 7 89 10 KILOMETERS S. Allshouse and E.A. Rodriquez, 1975; J.F. Coburn and R. Tal, 1976; W. E Pass Transverse Mercator projection G U H Gaum, M. Goddard, and K.L. Marcus, 1977; E.L. Mathieson and N.B. Shew, Wenatchee P T R WALL O 1 0 1 234 5 MILES 1978; D.B. Booth, 1978-82; S.F. Connally, S.L. Sandberg, F. Beall, F.C. NORTHWEST N IC Moser, and S. Cook, 1981; C. Eddy, K.M. Ort, and T. Schirmer, 1982 OW CASCADE T W S E 5000 0 5000 10000 15000 20000 25000 FEET WASHINGTON H SYSTEM K N IT A
TRUE NORTH E C G Y A Digital database by R.W. Tabor R a O M I R VE kima R IC APPROXIMATE MEAN CONTOUR INTERVAL 50 METERS Edited by Dale Russell, Julia Thomas, and Jan Zigler; digital cartography by FA I-90 N ULT A DECLINATION, 2000 AREA OF QUADRANGLE LC NATIONAL GEODETIC VERTICAL DATUM OF 1929 Kathryn Nimz with assistance from Taryn A. Lindquist, Sara Boore, Susan SNOQUALMIE O V WENATCHEE Mayfield, and Kevin Ghequiere PASS 122° ° 47° ND 121 Manastash A ° STRAIGHT Manuscript approved for publication January 23, 1995 Ridge Y R 47 30' R i Snoqualmie area TA v Mt Rainier N e North E r Pass DIM Bend SE LI Unconsolidated deposits Y N AR E SNOQUALMIE (includes some deposits of TI A QUATERNARY 0 60 KILOMETERS TER MENT BATHOLITH Rimrock Lake the Cascade Arc) 0 60 MILES inlier Rocks of Cascade Arc Granite
C Mtn and REE Pliocene Regional overview of geologic setting for Snoqualmie Pass quadrangle, Washington. Arc plutons are Miocene Figure 1. Chester Morse Basalt, andesite, not shown. Wenatchee 1¡ by 2¡ quadrangle is composed of the Skykomish River, Chelan, Snoqualmie Pass, and K Lake TEANAWAY RIVER and minor dacite Wenatchee 1:000,000-scale quadrangles (shown in magenta). BLOCK Columbia River Basalt Group Ka Miocene c Keechelus h Andesite basalt, rhyolite, and es Cle Elum dacite (Fifes Peak Formation) Lake s R Lake id g e Andesite, basalt, and dacite (includes Kachess Tonalite to granite Ohanapecosh Formation, Lake (includes rocks of iver volcanic rocks of Mt Daniel)
A' R Snoqualmie batholith, Rampart er Goat Carbon River stock) A Grass Cascade Box iv Mountain A'' Howard Hansen Roslyn Crest Ridge Ridge Reservoir Oligocene METERS Mountain R s METERS
le Elum
STRAIGHT CREEK FAULT ZONE tu SECTION
BEND IN ROCKS WEST OF ROCKS EAST OF
C 2000 B-B' Tnbg 2000
ap Tdrd
Tdv F Hansen Creek Cooper River Gold Creek Gold Tnbg GREEN RIVER -- CABIN CREEK BLOCK STRAIGHT CREEK FAULT STRAIGHT CREEK FAULT
SECTION Tnr Q KJis Tdv AULT Cedar River Cedar Tnr
Tnbg W reen River Ked Tss Enumclaw Coal Creek 1500 Tnmc 1500 TERTIARY Teg G Teg Kes Tdgr Tdgr Tss W White River To Tsgs Tstn Ked Green River-Cabin Creek Block Teanaway and Manastash River Blocks Teg Tf Tng Tnmc Tng Tnmc Q Tns Kes Tss HITE Hu Q Q Q Tsgs Q Tss Q c 1000 Creek Prarie South Teg Tf To Q Q 1000 ke Q Tfcr Tf Tf lb Tp Q To Q Tfce Q Q Tfrt Q erry 500 Q Q 500 M RIV SEA LEVEL Tss SEA LEVEL ER o Interbedded fluviatile sandstone Oligocene(?) Tdgr un Tf To ta Hicks and volcanic rocks (includes Fluviatile sandstone, shale, and 500 500 in Pugit Group, Naches Formation) coal (Roslyn Formation) Tns Butte 1000 D 1000 Tfcr D To M F 1500 To 1500 Z Tip FAULT
Marine sandstone and shale Basalt and andesite flows and Eocene 2000 2000 Naches (Raging River Formation) breccia (Teanaway Formation, and 500 meters=1640.4 feet basalt of Frost Mtn) Pass Unconsolidated deposits, (Q) undifferentiated and exaggerated in thickness, small areas not shown Z MANASTASH ON Clear West E RIVER BLOCK Fluviatile sandstone and dacitic volcanic Peak CARBON RIVER rocks (Includes Swauk, Manastash, and Taneum Formations) 47°00' STOCK
0 5 10 km Unconformity
Terrane units 0 5 10 m WASHINGTON ROCKS SOUTHWEST ROCKS IN ROCKS NORTHEAST B B' C C' OF DARRINGTON- DARRINGTON-DEVILS OF DARRINGTON-
Blazed iver METERS METERS METERS METERS Area of Figure 2 R DEVILS MTN MTN FAULT ZONE DEVILS MTN WHITE RIVER FAULT ZONE Little Naches River
Ridge a 2000 Huckleberry Cougar 2000 2000 2000 Chenuis Creek Tta FAULT ZONE (DDMFZ) FAULT ZONE
Crow Creek Easton Mountain Mountain Tf Te Tnr Tnr Kbg Cle Elum Lake
Tfb WHITE RIVER FAULT ZONE 1500 Tfcr Tf Tfce 1500 1500 Tnb Tn Tbf Tm akim Ridge 1500 Tfce Teg Tf Tf Tn Y EXPLANATION Tfci Big Creek White River Teg Tf Tns Khb Tf Green River Tfrt Q Q To Kes West Fork Teanaway River Tt Tf Tfst To To Tfrt Tt Trm Trl 1000 Q 1000 1000 Q Tssp 1000 Teg Tf Q Q Rocks of western and eastern Serpentinite and argillite
ÑDotted where concealed Cretaceous Contact AND (OR)
Q TERTIARY Q and (or) Late
500 500 500 500 mlange belts (includes matrix tectonic breccia Middle Eocene CRETACEOUS To Tfst FaultÑDotted where concealed Lookout Mtn Formation of (tectonic complex of SEA LEVEL SEA LEVEL SEA LEVEL SEA LEVEL Stout, 1964, Quartz Mtn stock) Stout, 1964) To To Ked 500 To 500 500 500 Structural block boundary and fault
Tcr Early 1000 1000 ÑDotted where concealed. 1000 1000 Syncline CEOUS Easton Metamorphic Suite1 CRETA- Arrow indicates plunge Cretaceous 1500 1500 1500 Tss 1500 (includes tonalite gneiss of ÑDotted where concealed. Hicks Butte, tectonic zone) 2000 2000 2000 2000 Anticline Arrow indicates plunge 500 meters=1640.4 feet 500 meters=1640.4 feet
Unconsolidated deposits, (Q) undifferentiated and exaggerated in thickness, small areas not shown Unconsolidated deposits, (Q) undifferentiated and exaggerated in thickness, small areas not shown Early 1 CRETA-
Ultramafic rocks JURASSIC CEOUS OR Late Jurassic (Ingalls Tectonic Complex) Cretaceous or Figure 2. Generalized geologic map of Snoqualmie Pass quadrangle, Washington. DDMFZ, Darrington-Devils Mountain Fault Zone. TO Metamorphic rocks of PERMIAN North Peak1 DEVONIAN
1Unit shown by protolithic age GEOLOGIC MAP OF THE SNOQUALMIE PASS 30×60 MINUTE QUADRANGLE, WASHINGTON By For sale by U.S. Geological Survey, Information Services, Box 25286, R.W. Tabor, V.A. Frizzell, Jr., D.B. Booth, and R.B. Waitt Federal Center, Denver, CO 80225, or call 1–888–ASK–USGS
Printed on recycled paper 2000 Available on World Wide Web at http://geopubs.wr.usgs.gov/i-map/i2538