25

56

70

45

60

20

30

60

36 55

32

55

45

55

40

4535

44

4532

35

40

4555

45

50

45

34

40

40

40

30

42

50

38

68

80

56

50

60

4242

55

25

50

45

45

40

50

50

50

50

55

42

3535

4070

45

30

50

45

40

60

44

40

48

55

60

55

65

55

60

50

50

50

45

60

60

54

50

4850

80

65

42

40

56

40

55

45

60

50

40

40

55

75

30 66

55

66

55

46

55

52

48

40

58

58

45

40

60

40

55

60 56

45

15

50

35

36

15

16

15

20

20

35

60

35

36

10

30

24

32

40

72

50

30

50

20

60

50

50

35

55

60

50

45

40

22

45

50

45

45

40

65

35

70

30

40

55

50

6069

35

2535

44

55

45

32

45

50

55

45

35

35

46

30

45

35

38

40

45

40

35

60

4830

27

36

22

40

50

34

36

28

45

30

40

45

32

38

30

28

30

30

52

55

34

22

50

72

55

60

40

48

38

50

25

45

42

22

35

30

55

40

36

38

34

4230

32

35

57

26

26

30

26

38

62

40

25

20

32

30

32

26

8

26

5

10

15

30

Qd

Zpq

Tsl

Tsl

Qt

Zc

Qd

Qd

Tsl

Cb

Zpa

Zc

Zpa

Qd

Qd

Zpa

Zc

Zc

Zc

Zm

Qt

Zc

ZcZm

Qd

Zc

Zc

Zpq

Cb

Qt

Zpc

Zpc

Zpd

Zpq

Zpq

Tsl

Qt

Zpu

Zb

Zpa

Zpa

Qd

Zpu

Qt

Zpd

Zpd

Zpc Zpd

Zpc

Zpc

Zpc

Zpd

Zpd

Qt

Zpq

Zpq

Zpq

Zpd

Qt

Zpc

Zpc

Zpq

Zpd

Zpc

Zpc

Zpd

Zpq

Qt

Zpu

Zb

Zpu

Zpu

Zpq

Zpu

Zpa

Zc

Zc

Zb

Zb

Zpa

Zpa

Zi

Zc

Qt

ZiZm

Zi

Zi

Zc

Qt

Zi

Zc

ZcQt

Zpa

Qd

Zc

Zc

Zc

Zpa

Zpa

Zb

Zc

Zc

Zc

Zc

Zi

Zc

Qd

Zc

Zb

Zpa

Qd

Cbo

Cb

Cb

Cb

Cb

Zm

Tsl

Zi

Qd

Ql

Qd

Tsl

Cgj

Cgj

Qal

Tsl

Cb

Cb

Zc

Zc

ZpaZm

Zpa

Zb

Ql

Tsl

Zpu

Zc

Zb

Tsl

Zpu

Zi

Zi

Zc

ZmZi

Zm

Zpa

Ccm

Qt

Zpc

Zpc

Zpu

Qt

Zm

Cb

Zm

Ccm

Cgj

Zm

Cgj

Ccm

Qt

Zpd

Zpc

Qd

Cgj

Zpu Zb

Zm

Cgj

Ccm

Cgj

Qd

Qd

ZiZm

Zc

Zi

Zc

Zpa

Qd

Zc

Qt

Zi

Zi

Zc

Cgj

Zc

Zc

Zc

Cb

Qt

Zpa Zc

ZcZpa

Zc

Cgj

Cb

Cb

Zc

Cgj

Zpa

Cb

Zc

Cbo

Qt

Cb

Cn

Cbo

Cn

Cbo Cn

Csw

Csw

Cbo

Qt

Cn

ZmZm

Zm

CgjCcm

Zi

Zi

Ccm

Zm

Qt

Zm

Zc

Zi

Zi

Zi

ZiZi

Zm

Zi

Zm

Cgj

Cgj

Cb

Cgj

Cn

Cgj

CgjCb

Cb

Cb

Qt

Ccm

Ccm

Ccm

Zc

Zpa

ZcZc

Zi

Zm

Zm

Zm

Zi

Zc Zi

Zm

Zi

Zc ZiZm

Zm

Ql

Ql

QTgv

QTgv

QTgv

Zm

Qal

Zi

QTgv

Ql

Zm

Zc

Ql

QTgv

Qd

Ql

QTgv

QTgv

QTgv

QTgvCsw

Zc

Csc

Cn

Cn

Csw

QTgv

Ql

Ql

QTgv

QTgv

Ql

QTgv

Qt

Csw

Cn

Cbo

Ql

Ql Csc

Qal

Cb

QTgvCgj

QTgv

Ql

Cb QTgv

Ql

QTgv

QTgv

Ql

Csw

Cbo

QTgv

ZmCcm

Ql

QTgvQTgv

MOSCOW-BOISE-POCATELLOIDAHO GEOLOGICAL SURVEY

PLATTGEOLOGIC MAP 22

limestone; some medium- to thick-bedded mottled limestone in upper part; in

quadrangles, Power County, Idaho: U.S. Geological Survey Bulletin 1399, 115 p.Trimble, D.E., and W.J. Carr, 1976, Geology of the Rockland and Arbon

and Power counties, Idaho: U.S. Geological Survey Bulletin 1400, 88 p.Trimble, D.E., 1976, Geology of the Michaud and Pocatello quadrangles, Bannock

Cambrian rocks in southeastern Idaho: U.S. Geological Survey ProfessionalOriel, S.S., and F.C. Armstrong, 1971, Uppermost Precambrian and lowest

Ludlum, J. C., 1942, Pre-Cambrian formations at Pocatello, Idaho: Journal of Geology,

sandstone. Thickness at least 300 meters with no known base. Mountain, three isolated outcrops of grayish green, poorly sorted, feldspathic weathers light gray to light brown. Includes, on the west side of Scout tan to gray cobble conglomerate with interstitial and interbedded sandstone;

Scout Mountain Member, lower cobble conglomerate part (Late Proterozoic)--Massive,

sparsely exposed to be mapped separately. Thickness approximately 100 Bannock Volcanic Member of Trimble (1976) because this rock type is too Mountain Member. Includes the slightly metamorphosed mafic lava in the to brown. Forms a swale between resistant upper and lower parts of the Scout and sandstone, very poorly sorted; typically tan to greenish gray, weathering

Scout Mountain Member, middle diamictite part (Late Proterozoic)--Cobbles, pebbles,

weathering tan, white and purple; minor beds of grit and conglomerate.Scout Mountain Member, upper quartzite part (Late Proterozoic)--Gray quartzite

Approximately 600 meters thick. beds in the bottom 10 meters. Equivalent to the "varved slate" of Ludlum (1942). and siltstone weathers distinctive silvery gray; a few thin limestone or dolomite

Upper Member (Late Proterozoic)--Medium and dark gray, finely laminated argillite

Pocatello Formation (Late Proterozoic)

Total thickness about 100 meters. gray to brown; interbedded with dark gray limestone beds typically 10 meters thick.Blackrock Canyon Limestone (Late Proterozoic)--Tan sandstone and siltstone weathers

of millimeters are distinctive. Thickness 900 meters. to siltite weathering tan to olive; mud cracks and irregular bedding on a scalePapoose Creek Formation (Late Proterozoic)--Gray to brown, very fine-grained quartzite

purple shale lenses near the top. Approximately 1 kilometer thick. minor grit and conglomerate beds; a few green phyllitic siltstone beds andCaddy Canyon Quartzite (Late Proterozoic)--Tan, vitreous, white-weathering quartzite;

color and lack of any carbonate. Thickness about 300 meters. sandstone beds. Can be distinguished from other fine-grained units by its greenInkom Formation (Late Proterozoic)--Green siltstone and mudstone; a few micaceous

quartzite; minor light-colored quartzite, argillite, and conglomerate beds.Mutual Formation (Late Proterozoic)--Purple and maroon quartzite and pebbly

bedded. Approximately 600 meters. fine-grained quartzite; weathers white, pink, tan, and brown; medium to thickCamelback Mountain Quartzite (Lower Cambrian)--Tan to light brown, medium- to

tan to brown sandstone. A few meters of limestone near the middle. ThicknessGibson Jack Formation (Lower Cambrian)--Dark gray shale; minor green mudstone and

Trimble and Carr (1976). Thickness 300-500 meters. Shale of Oriel and Armstrong (1971); equivalent to the Elkhead Limestone of Oriel and Armstrong (1971); may include the limestone part of the Leadbell lower part some thin-bedded oolitic limestone similar to Bancroft Limestone of

Thickness about 300 meters.

Thickness about 800 meters.

Blacksmith and Bancroft Limestones, undifferentiated (Middle Cambrian)--Gray

mostly nodular to platy limestone in lower part. Thickness 500-600 meters. with thin limestone beds; siltstone and some nodular limestone in upper part;Bloomington Formation (Middle Cambrian)--Green mudstone and shale interbedded

v. 50, p. 85-95.

Paper 394, 52 p.

meters.

Zpc

Zpd

Zpq

Zpu

Zb

Zpa

Zc

Zi

Zm

500-600 meters.

C– gj

C– cm

C– b

C– bo

REFERENCES

Thickness 300 meters.

DESCRIPTION OF MAP UNITS

dolomite, and limy siltstone. Thickness 200-300 meters.Nounan Formation (Upper and Middle Cambrian)--Gray interbedded limestone,

most quartzite beds. Upper contact placed at the highest quartzite beds. limestone and dolomite; characterized by chalky-weathering feldspar grains inWorm Creek Quartzite (Upper Cambrian)--Gray to tan quartzite with interbedded

intraformational conglomerate and chert; a few dolomite beds near the top.St. Charles Limestone (Upper Cambrian)--Dark and medium gray limestone with minor

characteristic pink near exposures of carbonate rocks. Exposed thickness about to pale green felsic tuff. Diamictite near exposures of older rock; weathers conglomerate, tuffaceous sandstone, and mudstone interfingering with whiteSalt Lake Formation (Pliocene and Miocene)--Heterogeneous unit including pink to tan

cemented. Thickness exceeds 70 meters.Gravel (Pleistocene and/or Pliocene)--Coarse gravel to sand; consolidated and weakly

Talus (Holocene and Pleistocene)--Large angular blocks at the base of cliffs and steep

alluvium too small to show separately. Thickness generally 2-5 meters. includes colluvium on hillsides and slumped material; includes in a few places rounded rock debris, sand, and mud; unconsolidated and generally unstratified;Unconsolidated debris (Holocene and Pleistocene)--Very coarse to fine, angular to

obscures underlying rocks; small accumulations not shown. Thickness generallyLoess (Holocene and Pleistocene)--Tan and buff unbedded silt, shown only where it

Maximum thickness greater than 5 meters. bottoms and alluvial fans. Grades laterally into and locally includes colluvium.Alluvium (Holocene and Pleistocene)--Tan unconsolidated sand and gravel in valley

Thickness about 250 meters.

Tsl

1 kilometer.

C– n

C– sw

C– sc

hillsides.

5-10 meters.

QTgv

Qt

Qd

Ql

Qal

1998Lucian B. Platt

GEOLOGIC MAP OF THE SCOUT MOUNTAIN QUADRANGLE, BANNOCK COUNTY, IDAHO

CORRELATION OF MAP UNITS

Zpc

Zpq

Zpd

Zpa

Zpu

Zb

Zi

Zc

C– gj

C– cm

Zm

C– bo

C– b

C– sc

C– sw

C– n

Ql

Unconformity

Unconformity

Qal

QTgv

Tsl

Qd Qt

PROTEROZOICLATE

LOWERCAMBRIAN

UPPERCAMBRIAN

MIDDLECAMBRIAN

PRECAMBRIAN

PALEOZOIC

TERTIARY

Pleistoceneand/or

Pliocene

Pliocene

Mioceneand

Pleistocene

Holoceneand

QUATERNARY

CENOZOIC

University of Idaho, Moscow, Idaho 83844-3014Published and sold by the Idaho Geological Survey

Control by USGS and USC&GS.

Topography by photogrammetric methods from aerialphotographs taken 1967. Field checked 1968.

Polyconic projection. 1927 North American datum100,000-foot grid based on Idaho coordinate system,east zone. 1000-meter Universal TransverseMercator grid ticks, zone 12.

Base map USGS Digital Raster Graphic. Reviewed by Kevin Hefferan, University of Wisconsin-Stevens Point.

Survey’s Digital Mapping and Information Lab.Digital cartography by Jane S. Freed at the Idaho Geological

Field work conducted in 1977-1978, 1986

Thrust fault: dashed where approximately located; teeth on upper plate.

Strike and dip of fracture cleavage.

Strike and dip of beds.

Contact: dashed where approximately located.

Fault: dashed where approximately located; dotted where concealed;bar and ball on downthrown side.

45

5

SYMBOLS

NATIONAL GEODETIC VERTICAL DATUM OF 1929

1

1

1/2

SCALE 1:24,000

CONTOUR INTERVAL 40 FEET

0.5 0

0

1 KILOMETER

1 MILE

GN

UTM GRID AND 1968 MAGNETIC NORTHDECLINATION AT CENTER OF SHEET

0 53

17

MN

IDAHO

QUADRANGLE LOCATION