geology of the greens creek mine area, alaska · gallagher t system greens creek thrust system...

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Fowler

Fowler

LilSore

Creek

Creek

Creek

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ekZi

nc

Creek

Bruin

Cub

Cre

ek

Creek

Cliff

Creek

Greens

Creek

Gallagher

CreekSore

Big

Creek

Greens

Creek

Cascade

Creek

Zinc

YOUNG BAY

KillerCreek

Ha

wk

I n

l et

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YOUNG BAY SHEAR ZONE

YOUNG BAY SHEAR ZONE

HAWK

IN

LET SHEAR ZON

E

ZINC

CREEKTHRUST

UPPER

UPPER

SHEAR

SHEAR

ZONE

ZONE

CLIFF CREEK

THRUST

GALLAGHER

FAULTSYSTEMGREENS

CREEK

THRUST

MAKI FAULT SYSTEM

A–ROAD

Cannery

SerpentineGulch

Killer CreekSerpentinite

B–R

OA

D

B–ROAD

Gallagher

Ridge

HawkInlet

Limestone

Blu

ff

A–Road Prospect

Lil Sore

Lower Zinc CreekUpper Zinc Creek

Lakes District

Mammoth Claims

Mammoth Ridge

Upper Bruin Creek

Lower Bruin Creek

Cub Creek

Upper Cliff Creek

Mine Portal

Gallagher Creek

Big Sore

Killer Creek

LowerCascade

UpperCascade

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Greens CreekMine

Pcs

Pcs

Pcp

Pcs

Drg

^hba

Qhse

^hpb

^hpb

^h(?)am

^h(?)am

^ha

^hba

Drg

Pcp

Qhpb

Drg

^ha

Drg

^hpb

Drg

^hpb

Pcp

KJs

^hpb

Drpb

Pcpw

^hpb

Drg

Drg

^hba

^hba

Pcp

^ha

^ha

^hba

^hba

Qha

^hc

^hba

^hba

Pcpw

Drg

^ha

^hpb

Drm

Drg

Pcs

Drg

Drpb

Drpb

Drg

^hgb

^hgb

^hba

^ha

Drpb

Drpb

^hpb

^ha

^ha

Drg

Drg

^ha

^hba

^hse

^ha

Drpb

Drg

^ha

^hba

^hbx

Drg

^hgb

Qhgc

Drpb

^hgc

Pcpw

Qha

Pcpw

Pcpw

^hgb

^ha

^hgb

Drg

Qhse

Drpb

Pcpw

^hpb

Drg

Pcs

Pcpw

Drg

^h(?)am

Drg

^hse

^hsr

^hgb

^hgb

Pcpw

Pcpw

^hbx

^ha

^ha

^h(?)am

Drg^hgc

Drg

Drg

Drpb

^hbx

^ha

Pcpw

^hbx

^hse

Drg

^ha

^hc

^hgb

^ha

^hgb

^hse

Drpb

^hgb

^hsr

^hsr

Pcpw

^hse

^hba

Drm

^hbx

Pcpw

^hl

Pcpw

^hsr

^hsr

Pcpw

^hgc

^hpb

^hse

^hpb

^hl

^ha

Drpb

^hc

^hpb

^hpb

Qhc

^ha

Drg

^hpb

^hsr

^ha

^hl

^ha

2,000 ft

3,000 ft

-1,000 ft

-2,000 ft

1,000 ft

Sea level

2,000 ft

3,000 ft

1,000 ft

B

^hgb

^ha

Drg

Drpb

^haDrpb

Drg

^hbx

Hyd

Unco

nfor

mity

Drm Drg

Pcs

B'

PcsDrg

Drg

Drg

^hbx

^hpb

^ha

^hc

^hgb ^ha

^hgb

^hgb

^ha

^hse

^ha^hc

^hpb

Drg

^ha

^ha

^hc

^hba

^hba

KJs

B"

-1,000 ft

-2,000 ft

Sea level

Looking west Looking north-northwest

-1,000 ft

1,000 ft

2,000 ft

3,000 ft

4,000 ft

-2,000 ft

Sea level^h(?)am

Pcs

DrpbDrpb Drg

A

^hgb

^hse

Drg

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^hse

Drg

Drg

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^ha

Drg

Drg

Drg

Drg

Drg

Drg

^hse

^hse

^ha

^ha

Killer CreekSerpentinite

Looking north-northwest NO VERTICAL EXAGGERATION

NO VERTICAL EXAGGERATION

Looking northeast

^hgc

^hgc

Mammoth RidgeGreen Carbonate

unit

^ha^ha

DrgDrg

^hsr Drg

Greens CreekOre Horizon

F2 Lower Limbon Section

^ha

F2

Drg

^hpb

F3

Pcpw

Broad F3 Structural Arch

^ha

^ha

^hba

^hba

^hba

Drg

^hl

^h(?)am

A"A'

-1,000 ft

-2,000 ft

Sea level

-1,000 ft

2,000 ft

3,000 ft

F2

ZIN

C C

RE

EK

TH

RU

ST

YOUNG BAYSHEAR ZONE

GR

EE

NS

CR

EE

K T

HR

US

T

Big

Sore

Cre

ek

UPPER SHEAR ZONE

CLI

FF C

REE

K T

RU

ST

Projection of the upper shear zone

Lil S

ore

Cre

ek

Fow

ler C

reek

Zinc

Cre

ek

Gre

ens

C

reek

Greens CreekMine (office)

Gre

ens C

reek

B

B'

B″

A

A'

A"

134°45’ 515000mE 134°40’ 520000mE 134°35’ 525000mE

134°45’ 515000mE 134°40’ 520000mE 134°35’ 525000mE

58°10’

58°10’

6445000mN

6445000mN

58°05’

6440000mN

6435000mN

58°05’

6440000mN

6435000mN

SCALE 1: 24 0001 MILE1 1/ 2 0

7000 FEET1000 10000 2000 3000 4000 5000 6000

.5 1 KILOMETER1 0

CONTOUR INTERVAL 100 FEETNATIONAL GEODETIC VERTICAL DATUM OF 1929

Compiled by N.A. Duke and A.W. West in 2001Data sources: Early compilations by T.C. Crafford (1980s), area mapping by N.A. Duke (1995–2001), detailed mapping by P.A. Lindberg (1994–1998), J. M. Proffett (1997–2001), A.W. West (2000–2001), and C.M. Schrader (2000)

U.S. DEPARTMENT OF THE INTERIORU.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1763

PLATE 4–1

Universal Transverse Mercator projection. 1927 North American Datum (NAD 27) 5,000-meter Universal Transverse Mercator grid ticks, zone 8, shown in blue100-foot contours are from 1997 AreoMap computer-drawn map,with modifications from field surveysContour elevations are relative to sea level

ALASKA

MAP LOCATION

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Although this information product, for the most part, is in the public domain, it also contains copyrighted materials as noted in the text. Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner. GEOLOGY OF THE GREENS CREEK MINE AREA, ALASKA

ByNorman A. Duke, Paul A. Lindberg, and Andrew W. West

2010

24°

TRUE

NOR

TH

MAG

NETI

C NO

RTH

APPROXIMATE MEANDECLINATION, 2001

Suggested citation:Taylor, C.D., and Johnson, C.A., editors, 2010, Geology, geochemis-

try, and genesis of the Greens Creek massive sulfide deposit, Admiralty Island, southeastern Alaska: U.S. Geological Survey Professional Paper 1763, 429 p., 7 plates on CD.

This and other USGS information products are available athttp://store.usgs.gov/ U.S. Geological SurveyBox 25286, Denver Federal CenterDenver, CO 80225

To learn about the USGS and its information products visithttp://www.usgs.gov/ 1-888-ASK-USGS

This report is available at:http://pubs.usgs.gov/pp/1763

Prepared in cooperation with the

KENNECOTT GREENS CREEK MINING COMPANY

EXPLANATION

Lithologic contact

Major fault—Brittle or ductile fault

D2 thrust fault—Sawteeth on upper (tectonically higher) plate

Inclined bedding (S0)—Showing strike and dip

Vertical bedding (S0)—Showing strike

Inclined S2 foliation—Showing strike and dip

Vertical S2 foliation—Showing strike

Inclined S3 foliation—Showing strike and dip

Vertical S3 foliation—Showing strike

L2 lineation—Showing bearing and plunge

L3 lineation—Showing bearing and plunge

D2 Fold—Showing plunge of axis and dip of axial plane

D3 Fold with inclined axial plane—Showing plunge of axis and dip of axial plane

D3 Fold with vertical axial plane—Showing plunge of axis

Overturned F2 or F3 fold—Showing axial trace of syncline (arrows ponting toward trough) or anticline (arrows pointing away from trough)

Prospects or mineral occurrences

BOUNDARIES

Admiralty Island National Monument

Experimental forest

Greens Creek joint venture

Land exchange

SURFACE FEATURES

Roads

Buildings

Streams

Waterbody

55

60

50

40

15

2035

3280

40

Juneau

Mansfield

Peninsula

Admiralty

IslandChatham

Strait

Young Bay

Stephens

Passage

DouglasIsland

Hawk

Inlet

MAP

AREA

134°30’134°45’135°00’ 134°15’

58°00’

58°15’

Inset map: Location of map, depicted in yellow, relative to the surrounding area.

Jurassic-Cretaceous

Upper Triassic

Seymour Canal flysch

HYD GROUP

Basalt

Limestone

Mine argillite

Conglomerate

Fault breccia

Siliceous rock

Serpentinite

Black phyllite

Permian-CarboniferousCANNERY FORMATION (?)

Siliceous white phyllite

Siliceous schistose sedimentary rock

Dolomitic phyllite

DevonianRETREAT GROUP

Greenstone

Marble

Gabbro Amphibolite

Green carbonate

Black phyllite

[See chapter 4 for more complete lithologic descriptions and a discussion of regional stratigraphic correlations.]

LIST OF MAP UNITS

KJs

^hgb ^h(?)am

^hl

^ha

^hc

^hbx

^hsr

^hse

^hpb

^hgc

^hba

Pcpw

Pcp

Pcs

Drm

DrpbDrg

DEFORMATION HISTORY

POST SEYMOUR CANAL FLYSCHD5—Major northwest-trending, generally right-lateral brittle or ductile faultsD4—Late reactivation of D2 thrust faults following D3D3—Northwest-southeast-trending chevron folds with spaced axial planar cleavageD2—Dominant east-west-trending, shallow, south-dipping, penetrative foliation

axial planar to recumbent isoclinal folds and north-verging thrusts (Zinc Creek and Upper Cliff Creek thrusts)

POST RETREAT GROUP, PRE CANNERY FORMATIOND1—Relict metamorphic segregation foliation in Retreat Group greenstone and

black phyllite

METAMORPHIC DOMAINSGreenschist facies—Greens Creek domain bounded by Young Bay shear zone

and Greens Creek thrust faultEpidote amphibolite facies—Northeast of Young Bay shear zone and southwest

of Greens Creek thrust faultGarnet amphibolite facies—South of Upper Cliff Creek thrust fault