DSrm

DSs DSs?

Dc

Dc Dc

Dj

Dj

Dj

Dj

Dp

Dp

Mca

Mca

Mca

Mca

Mca

Mca

Mca

Mca

Mcb

Mcb

Mcb

Mcb

Mcb

Mcb

Mca

Mcd

Mcl

Mcl

P*weu

P*weu

P*weu

P*weu

P*weu

P*weu

*wel

*wel

*wel

*wel

*wel

*wel

*wh

*wh

*wh

*wh

*wh

*wh

Qa

Qa

Qa

Qa

Qa

Qa

Qa

Qa

Qaf2

Qaf2

Qaf2

Qaf2

Qaf3

Qaf3

Qaf3

Qaf3

Qaf3

Qaf3

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qafc

Qao

Qao

Qao

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qc

Qcfg2

Ql

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls

Qls Qsbd2

Qsbd2

Qsbd2

SOp

SOp

St SOp

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tca

Tcac

Tcac

Tcar

Tcar

Tcar

Tcat

Tcat

Tcat

Tcc Tcc

Tcc

Tcc

Tcc

Tcc

Tcc

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcdd

Tcls

Tcls

Tcls

Tcls

Tcrt

Tcrt

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tcd

Tg

Tg

Tig

Tig

Tig

Tig

Tig

Tig

Tig

Tig

Tig

Tig

Tig?

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tiv

Tj

Qafc Qafc

A

C

A’

C’

B

B’

85

85

73

55 55

65

55

70

53

65

60 70

55

70

70

75

35

60 65 15 40

20 30

30

75

75

75

5

10

45

45

80

25 25

25

20

40

30

65

20

25 30

20 30

25 20

50

15

10

40

45

25

20

35

35

20

45

55

60

45 45

85

80

30 40

40

10

40

18

17 10

30

35

35

30

30

45

20

15

45

50 50

80

10

30

30

30 30

30 25

25

30

40

80

40

40 60

65

10

45

65

60 60 35

30

70

35

20 25

40 45

45

0

25

40

30

25 15

40 50

40

35

80

55

25

50

25

20 40

25

20 20

20

40

20

30

45

40

25

25 15

40

35

25

20

15

65

30

40

40

60

20

65

50

50

45

30

35

25

15

15

20

40

15

20 20

25

25 30

35

40

45

40 50

25

35

30

40

20

40

40 40

80

55

45

45

60

15

15

40

20

45

15

30

40 40

40

40 15

40

20

20

30

30

25

25

35

20

35

45 45

50 30

30

25 25 20

10

10

65 45

45

25

25

50 45

55

25

45

60

30

45

45 55

40

40 50

40

55

65

55

40

40

50

25

25

35

25

40

35

40 20 15

20

20

7 15

35

40

45

55

35

55

50

40

65

45 60 45

45

55

60

35

35

45 55 45

55

55

65

65

60

60

35

15

35 25

15

35

30

50

35 20

15

45

60

25

65 3070

35

20

20

20

35

30

25

15 40

30 55

45

10

45

30

15

40

20

10

20

0

25

70

50

20

35

40

25

5

5

45

65

65

65

60

55

35

45

45

40

40

40

60 35 40 30

50

45 45 30

15 20 35

30

20

40 30

55

45

50 40

45

40

50

55

80

0

30 55

30 30

65

40

50

30

30

45

60

50

45

50

40

50

35

40

5

10

25

20 30

35

50

45

60 35 50

45

25

45

45

40

65

50 50

45 30

45

40

60 30

30

55

50

30

25

30

20

25 70

20 30

35 30

25

20

35

20

15

15 25 5 30

0 0

30

30

25 25

30

30

60

45

25

25 25

30

15

45

35

45

55 25

30

40 15 35

40

25

55

35

25

10

50

50 55

25

30 35

25

20

25

10

45

45

45 55

35 45

60

40

50

35

35

70

35

35

40

40

40

35 35

25 30

50

40

40

50

20 40

20

65

75

60

70

25

65

75 85

60

40

50

80

20

60

40

20

35

32

20

40

20

30

30

40

70

20

25

20

30

75

52

60

25 25

20

15

15

20 25

25

35

30

20

15

40

40

20

30

45

60

20

15

25 30

35

12

20

25

45 45

20

25

55 20

35 30

20

25

25

30 30

40

20

15

20

50

25

10 30

25

15

25

30

35

15

25

45

35

25

45

25 20

40

20 

55 

65

70

70

52

0

0

70

70

80

65 65

50

70

70

80

80

15

20 40

80

60 55

75

60

65

30

25

40

50

55

80

20

45

25

35

35

40

40

30

35

15

70

18

30

F-1

X

F-5 X

F-2 F-4

F-3 F-2

X

X

X

X

LC-3

Qa Qa Qa Qc Qaf3 Qaf2

A

T

Tca

Tca

Tcar

TKbg

Mca

Mca

Mca

Mcd

Mcl

Mcl

Mcl

Dp

Dj

Dj

Dj

Dj

Dj

Dc Dj

Dc

SOu

SOu

Dc

Dc

Dc DSrm DSrm

DSrm

DSrm

DSrm

Mcd Mcd

Dp

Antler-age

thrust fault Antler-age

thrust fault

PINE

MOUNTAIN

FISH CREEK

CROOKS

CREEK

WEST FORK

FISH CREEK

A

T

Mcb

Mcb

Qafc

Qc

Qc

Qa

Dp

A

T

C

METERS

2,200

2,400

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0

C’

FEET

7,000

8,000

6,000

5,000

4,000

3,000

2,000

1,000

0

B–Bʹ 

SECTION

B B’

Qa

Qls

Qls

Qls

Qls

Qsbd2

Tiv

Tiv

Tig?

Tcd

Tcd

Tca Tcrt

TKbg

P*weu

P*weu

*wel

*wel

*wel

*wh

*wh

DSs

DSs

SOp

Mcb

Mcb

Mca

Mcd

Mcl

SOu

Dp

Dj

Dj

Dc

Dc

Dc

DSrm

DSrm

DSrm

Antler-age

thrust fault Antler-age

thrust fault

Antler-age

thrust fault

Antler-age

thrust fault

COPPER BASIN

THRUST FAULT

PINE

MOUNTAIN

FISH CREEK

METERS

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0

FEET

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

C–Cʹ 

SECTION

?

?

?

? ?

?

?

?

?

?

?

?

?

?

?

Qa Qafc Qafc

Qafc

Qafc

Qc

Qc

Qsbd2

Tiv

Tiv

Tca

Tcrt

*wel

*wel

*wel

*wh

*wh

*wh

*wh

*wh

DSs

DSs

DSs

DSs

DSs

DSs?

DSs?

St

St

St?

SOp

SOp

SOp

SOp

Mca

Mcd

Mcl Dp

Dj

Dj

Dc

Dc Dc

DSrm

TKbg

TKbg

P*weu

P*weu

P*weu

Qafc

Tcd

LONG CANYON

Huff Creek

FISH CREEK

COPPER BASIN

THRUST FAULT

Antler-age

thrust fault

Antler-age

thrust fault

Antler-age

thrust fault

A A’

METERS

2,200

2,000

1,800

1,600

1,400

1,200

1,000

800

600

400

200

0

FEET

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

Lacustrine deposits (Holocene)

Alluvium of Fish Creek drainage (Holocene and late Pleistocene)

Landslide deposits (Holocene and late and middle Pleistocene)

Alluvial and colluvial fan deposits (Holocene and late and middle Pleistocene)

Colluvium (Holocene and Pleistocene)

Fan alluvium 2 (late Pleistocene)

Old alluvium (middle and early(?) Pleistocene)

Older fan alluvium (middle and early(?) Pleistocene)

Carey pahoehoe and aa basalt-hawaiite flows (upper Pleistocene)

Basaltic pahoehoe flows, pyroclastic deposits and vent crater of Fish Creek Reservoir

 (inferred to be lower middle Pleistocene)

Rhyolitic ignimbrites

Gravel

Jasperoid (Oligocene(?) and Eocene(?))

Gossan (Miocene and post-Permian)

Dikes

Latitic ignimbrite of Stoddard Gulch

Dacite flows, domes, and interbedded ignimbrite

Dacitic ignimbrite

Tuff of Antelope Creek

Andesitic vitric-crystal tuff and tuff breccia

Andesite flows and dikes

Rhyolitic lithic-crystal tuff

Smiley Creek formation (informal unit of Paull, 1974)

Biotite granodiorite (Tertiary and Late Cretaceous(?))

Wood River Formation (Lower Permian and Upper and Middle Pennsylvanian)

Idavida Volcanics (Miocene)

Challis Volcanic Group (Eocene)

Eagle Creek Member (Lower Permian and Upper Pennsylvanian)

Lower part (Upper Pennsylvanian)

Upper part (Lower Permian and Upper Pennsylvanian)

Hailey Member (Middle Pennsylvanian)

Siltstone (Devonian(?) and Silurian)

Trail Creek Formation (Silurian)

Phi Kappa Formation (Middle and Lower Silurian and Ordovician)

Copper Basin Group, undivided (Upper and Lower Mississippian)

Argosy Creek Formation (Upper and Lower Mississippian)

Drummond Mine Limestone (Lower Mississippian)

Little Copper Formation (Lower Mississippian)

Picabo Formation (Upper Devonian)

Jefferson Formation (Upper and Middle Devonian)

Carey Dolomite (Middle and Lower Devonian)

Roberts Mountains Formation (Lower Devonian and Upper Silurian)

Upper Silurian and Ordovician rocks, undivided, only in cross section C–C’

LIST OF MAP UNITS

Ql

Qa

Qls

Qafc

Qc

Qaf2

Qao

Qaf3

Qcfg2

Qsbd2

Tiv

Tig

Tj

Tg

Tcd

Tcls

Tcdd

Tcat

Tcac

Tcar

Tca

Tcrt

Tcc

TKbg

P*weu

*wel

*wh

DSs

St

SOp

Mcb

Mca

Mcd

Mcl

Dp

Dj

Dc

DSrm

SOu

Ql

Qa

Qls Qafc

? ?

?

?

?

?

?

?

Qc

Qaf2

Qaf3 Qao

Qcfg2

Qsbd2

Tiv

Tig

Tj

Tg

Tcd

Tcls

Tcdd

Tcat

Tcac

Tcar

Tca

Tcrt

Tcc

TKbg

P*weu

*wel

*wh

DSs

St

SOp

Mcb

Mca

Mcd

Mcl

Dp

Dj

Dc

DSrm

SOu

?

CORRELATION OF MAP UNITS

[See Description of Map Units in pamphlet]

SURFICIAL DEPOSITS

IGNEOUS ROCKS

Sedimentary deposits Basalt lava flows

Craters of the Moon

volcanic field

Snake River Group

Idavada Volcanics

Hanging wall of

Pioneer thrust fault

Footwall of

Pioneer thrust fault

SEDIMENTARY ROCKS

Unconformity

Unconformity

Unconformity

Unconformity

Unconformity

Wood River

Formation

Copper

Basin

Group

Footwall of

Antler-age

thrust

Hanging wall of

Antler-age

thrust

Challis Volcanic Group

Holocene 

Late

Pleistocene

Middle

Pleistocene

Early

Pleistocene

Miocene

Oligocene

Eocene

Paleocene

Upper

Cretaceous 

Lower

Permian

Upper

Pennsylvanian

Middle

Pennsylvanian

Lower

Pennsylvanian

Upper

Mississippian

Lower

Mississippian

Upper

Devonian

Middle

Devonian

Lower

Devonian

Upper Silurian

Middle Silurian

Lower Silurian

Upper

Ordovician

Lower

Ordovician

QUATERNARY

TERTIARY

CRETACEOUS

PERMIAN

PENNSYLVANIAN

MISSISSIPPIAN

DEVONIAN

SILURIAN

ORDOVICIAN

Contact—Dashed where approximately located

Faults

Normal—Dashed where approximately located; dotted where

 concealed. Bar and ball on downthrown side; tick indicates

 measured dip on fault surface. Showing relative motion in

 cross section: A, away from observer; T, toward observer 

EXPLANATION OF MAP SYMBOLS

A

T

65

Anticline—Dashed where approximately located

Syncline—Dashed where approximately located

Strike-slip, right-lateral—Dashed where approximately located.

 Arrows indicate relative right-lateral movement

Thrust of Mesozoic age (showing probable later normal movement)—

 Dashed where approximately located, dotted where concealed;

 Open sawteeth on upper plate

Strike and dip of beds in sedimentary rocks and tuffaceous sediments in

 volcanic rocks

Strike and dip of flow layering

Inclined—Showing strike and direction of dip

Horizontal

Vertical—Showing strike

Overturned—Showing strike and dip

30

Inclined—Showing strike and direction of dip. Inclined flow layering in

 rhyolitic ignimbrites

30

Inclined—Showing strike and direction of dip; circle indicates top

 determined on sedimentary structures

30

44

Overturned—Showing strike and dip. Ball shows top direction of beds

 known from local features

75

Vertical—Showing strike. Ball shows top direction of beds known

 from local features

Thrust of Antler age (post-Devonian to pre-Middle Pennsylvanian)—

 Dotted where concealed; Closed sawteeth on upper plate

Lineament—Identified from aerial photograph

Inclined crenulated or warped bedding—Showing approximate strike

 and dip of severely deformed beds

Approximate—Showing strike and dip 30

55 

Inclined—Showing strike and direction of dip. Inclined flow layering in

 igneous rocks

30

Inclined—Showing strike and direction of dip. Inclined flow layering in

 volcanic rocks other than ignimbrites

30

Cleavage

Rim of volcanic crater—Hachures point toward central depression

Drill hole in Long Canyon area (Cominco American Resources, Inc.)

Fossil or sample locality

Spring

Photograph location and direction of view

Inclined—Showing strike and dip 20

F-1

Vertical or near vertical—Showing strike

X

Fault interpreted to have movement in both normal and reverse

 directions—Cross sections only

Strike-slip, left-lateral—Dashed where approximately located.

 Arrows indicate relative left-lateral movement

Breccia

Geologic Map of the Fish Creek Reservoir 7.5’ Quadrangle, Blaine County, Idaho

By

Betty Skipp and Theodore R. Brandt

2012

Scientific Investigations Map 3191

Pamphlet accompanies map

U.S. Department of the Interior 

U.S. Geological Survey

Any use of trade, product, or firm names is for descriptive purposes

only and does not imply endorsement by the U.S. Government

For sale by U.S. Geological Survey Information Services, Box 25286,

Federal Center, Denver, CO 80225

1-888-ASK-USGS

ArcGIS geodatabase, coverage, and shapefile format files, and a PDF

for this map are available at:

http://pubs.usgs.gov/sim/3191/

Suggested citation:

Skipp, Betty, and Brandt, T.R., 2012, Geologic map of the Fish Creek

Reservoir 7.5’ quadrangle, Blaine County, Idaho: U.S. Geological

Survey Scientific Investigations Map 3191, 1 sheet, scale 1:24,000,

pamphlet, 15 p.

CONVERSION FACTORS

Multiply By To obtain

inches (in.) 2.54 centimeters (cm)

feet (ft) 0.3048 meters (m)

miles (mi) 1.609 kilometers (km)

CONTOUR INTERVAL 40 METERS

NATIONAL GEODETIC VERTICAL DATUM OF 1929

QUADRANGLE LOCATION

IDAHO

SCALE 1:24 000

1 1/ 2 0 1 MILE

1 .5 0 1 KILOMETER

APPROXIMATE MEAN

DECLINATION, 2012

Base from U.S. Geological Survey, 1979

Fish Creek Reservoir, Idaho

Projection and 10,000-meter grid, zone 12

Universal Transverse Mercator

10,000-foot grid ticks based on Idaho

coordinate system, central zone

1927 North American Datum

Geology mapped by Betty Skipp, 1991–1994, 2008;

Assisted by June Skinner Hornsberger, 1992;

Beth Geir, 1993; Jennifer Carr Merrill, 1994; and

Jean M. LaDue, 1991–1994, 2008

Digital map database prepared by Theodore R. Brandt

Editing and digital cartography by Gayle M. Dumonceaux,

and Lisa Rukstales, Denver Science Publishing Network

Manuscript approved for publication November 14, 2011