SAND RIDGE ANTICLINE

GREAT NORTH MOUNTAIN ANTICLINORIUM

TAVENNER RIDGE ANTICLINE

TUNNEL RIDGE SYNCLINE

MOUNT PLEASANT SYNCLINE

HAYFIELD

RIDGE SYNCLINE

Db

_e

_e

Df

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Df

O_c

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Dn

Dn

Stu

Dfl

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Dfu

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Dmr

Dmr

Df

Dfl Dfu

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Sto

Do

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Smk

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Qa

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Ojo

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On

Qa

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Dhl

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Sto

Sto

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Dn

Do

DSk DSk

Qdf

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Sk

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Dm

Dm

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Do

Do

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Dmch

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Dfl

Df

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Dfu

Dh

Dmr

Dhl

DSk

Dm

Dm

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Skr

Skr

Skr

Om

Om

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Dfl

Df

Df

Df

Dfu

Dfu

Df

Dfl

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Dh

Dm Dmc

Dm

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Sto

Sto

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45

80

71

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57

62

66

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65 71 68 69

67

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10

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57 65

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52

60

44

42

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31

35

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20

31

34 14

21

38

50 72

65

50 80

17

10

25

58

25 24

65

22

13

25

72

47

29

24 65

28

60

43

15

10

10

58

47

45

30

10

47

25

63 14

25 22

32

60

85

18

50

45

70

12

48

52

80

38

45

53

38

40

25

17

12

20

58

23 30

47

50

55

50

40

85

50

40

51

62

52

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85

37

38

22

30

47

22 19

25

22 30

40

45

35

48

80

55

52

42

48

70

60

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42

40

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55

45

33

35

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58

60

15

37

26 65

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15

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12

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27

10

85

30

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15

30 24

54

55

50

55

72

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63

51

26

25

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37

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35 35

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10 30

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12

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20

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37

26

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27

32

28

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21

27 32

29

33

35

34

35

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35

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36

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53

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51

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55

51

55

47

19

40

40

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43

77

35

44

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50

60 55

55

55

20

25

10

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16

25

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30 41

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13

48

24

66

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47

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67

70

68

72

65

28

65

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50

31

38

33

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75

22

31

47

41

40

37

31

80

40

42

42

40

60

82

81

74

88

87

88

18

18

15

16

73

86

88

88

40

34

36

37 39

41

43

40

35

36

32

34

34

30

17

20

22 24

71

72

70

60

53

70

60

40

30

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73

7260 61

45

38

42

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72

21

21

27

30

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86

35

66

58 45

65

48

50

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65 40

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54

70

80

24

25

28

56

24

15

32

40

41

41

33

32 45 45

20

19

57

65 28

65

45

60

60

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75

21

28

63

22

27

66

10

20

55

13

70

76

45

45

40

15

15

70

20

35

30

45

13

70

15

30

35

56

19

54

30

32

20

20

30

25

16

28

25

45

47

73

10 10

45

50

41

50

30

20

15

72

65

32

50

45

75

55

21

20

48

55

35

7

10

10

76

73

77

80

85

85

75

55

50

85

62

48

60

68

82

55

70

58

72

71

63

80

80

83

75

50

18

75

68

75

65

35

14

80

88

70

65

60

58

38

85 65

40

55

70

47

88

80

48

84

55

55

70

60

57

85

85

45

38

55

65

70

75

29

B'

B

A

A'

FORMATION AND MEMBER LITHOLOGY

APPROXIMATE

THICKNESS, IN FEET

(Not to scale)

1 foot (ft)=0.3048 meter

Conococheague Limestone

Elbrook Formation

Stonehenge Limestone*

Stoufferstown Member*

Rockdale Run Formation*

Pinesburg Station Dolomite*

New Market Limestone

Chambersburg Formation*

Martinsburg Formation

Oswego Sandstone

Juniata Formation

Tuscarora Sandstone

Rose Hill Formation

Keefer Sandstone

Bloomsburg Formation

McKenzie Formation

Wills Creek Formation

Tonoloway Limestone

Helderberg Group

Oriskany Sandstone

Needmore Shale

Marcellus Shale

Mahantango Formation

Chaneysville Siltstone Member

Clearville member

Brallier Formation

Foreknobs Formation

lower ridge-forming unit 

upper ridge-forming unit

Alluvium and colluvium

Hampshire Formation

DEVONIAN SILURIAN ORDOVICIAN CAMBRIAN

Middle Upper Lower

Beekmantown Group*

Middle Upper

SYSTEM

SERIES

FOSSILS

≥2,500 ft

2,200–2,600 ft

770 ft

1,200 ft

≤700 ft

80–200 ft

500 ft

≤4,000 ft

?

<100 ft

50–200 ft

300 ft

350 ft

30–50 ft

 ~200 ft

500 ft

300–600 ft

100–140 ft

100 ft

140–175 ft

200–500 ft

1,100–1,350 ft

165–245 ft

100–180 ft

1,250–1,800 ft

2,500–2,800 ft

600 ft

500 ft

up to 3,600 ft (<1,700 ft

exposed in the quadrangle)

5–20 ft

lower upper Lower Upper Middle

Big Spring Station Member ~200 ft

80 ft

Stickley Run Member*

Keyser Formation 200–250 ft

150–400 ft

*not exposed in quadrangle

EXPLANATION

Lithologic patterns

Alluvium and colluvium

Sandy or silty shale

Interbedded sandstone and siltstone

Interbedded sandstone, siltstone, and shale

Bedded sandstone

Argillaceous or shaly sandstone

Clay or clay shale

Silt, siltstone, or shaly silt

Carbonaceous shale

Calcareous shale

Crossbedded sandstone

Conglomerate

Cherty limestone

Fossiliferous clastic limestone

Limestone

Nodular or irregularly bedded limestone

Argillaceous or shaly limestone

Quartzite

Crossbedded subgraywackee

Interbedded limestone and shale

Dolomitic limestone

Cherty dolomite

Dolomite

Silty limestone

Sandy limestone

Sandy dolomite

Silty dolomite

Argillaceous or shaly dolomite

Regional unconformity

Major fault zone

Commonly ocurring fossils

Brachiopods

Gastropods

Corals

Bryozoans

Crinoids

Burrows

Ostracods

Graptolites

Nautiloids

Trilobites

Conodonts

Stromatolites

Stratigraphic Column for Frederick County, Va., With Generalized Unit Thicknesses 

Figure 3. Equal-area rose diagram of joint orientations in the 

Hayfield quadrangle. Petals represents joint azimuths (n=64) binned 

in 10° increments, dip to right of azimuth. Arrow indicates mean 

vector of 325.8°±113.8°.

W E

N

S

W E

N

S

Figure 2. Lower hemisphere equal-area stereographic projection of 

poles to planes of joints (n=64) in the Hayfield quadrangle with 

Kamb contours at a contour interval of 2 sigma. 

Figure 1. General geologic map of the Great Valley province in northern Virginia showing the location of the Hayfield 7.5-minute quadrangle, and inset map of the Hayfield 

quadrangle showing shaded relief and selected structural elements. Lithotectonic units on inset map: Silurian through Devonian rocks of the Valley and Ridge province and 

Cambrian and Ordovician rocks of the Great Valley province to the east of Little North Mountain, bounded by the North Mountain fault zone. Major folds in the Devonian 

shales, siltstones, and minor sandstones are also shown. Shaded relief from U.S. Geological Survey National Map.

EXPLANATION

Mississippian through Silurian rocks of the Valley and 

Ridge province—Mississippian rocks are absent 

from the Hayfield quadrangle area

Devonian and Silurian rocks of Massanutten Mountain

Martinsburg Formation (Upper and Middle Ordovician)

Middle Ordovician through Cambrian rocks, mainly 

carbonate

Early Cambrian and Neoproterozoic rocks of the Blue 

Ridge province

Thrust fault—Sawteeth on upper plate

Plunging anticline

Plunging syncline

Doubly plunging anticline

Doubly plunging syncline

WEST VIRGINIA

VIRGINIA

WEST VIRGINIA

VIRGINIA

BLUE 

RIDGE 

PROVINCE 

Winchester

Strasburg

Harrisonburg

HAYFIELD

QUADRANGLE

HAYFIELD QUADRANGLE

MOUNTAIN 

MASSANUTTEN 

VIRGINIA

MAP LOCATION

HAYFIELD RIDGE SYNCLINE

TUNNEL RIDGE

SYNCLINE

TAVENNER

RIDGE ANTICLINE

SAND RIDGE ANTICLINE

GREAT NORTH MOUNTAIN ANTICLINORIUM

MOUNT PLEASANT SYNCLINE

NORTH

MOUNTAIN FAULT

ZONE

N

O

R

T

H

M

O

U

N

T

A I N

F

A

U

L

T

Z

O

N

E

Devonian through Silurian rocks

of the Valley and Ridge province

Middle Ordovician

through Cambrian rocks,

mainly carbonate

PROVINCE

VALLEY

GREAT

5

36

40

GREAT NORTH MOUNTAIN

ANTICLINORIUM

SURFACE

SURFACE

Little North

Mountain

Great North

Mountain

Shawnee Land

Mount Pleasant

Hogue Cr

Cove Lake

Wolf Spring Run

Hogue Cr

Bear Run

Whisson Ridge

FEET

1,000 feet=305 meters

Surficial deposits not shown

SEA LEVEL

1,000

2,000

1,000

2,000

3,000

B B'

FEET

SEA LEVEL

1,000

2,000

3,000

1,000

2,000

3,000

3,000

4,000 4,000

NO VERTICAL EXAGGERATION

MOUNT PLEASANT

SYNCLINE

BOBCAT TRL

BACK MOUNTAIN RD

CEDAR CREEK GRADE

Om

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DSls

Sto

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Do Sw

Sw Sb Sw Ojo Skr Stu

Om

Om

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Ojo

Stu Dmn

Swbm

Skr

DSls

Dm

Dm

Dmch

Dmc

Dmch Dm _e O_c

Swbm

Dmc

MOUNT PLEASANT

SYNCLINE

GREAT NORTH MOUNTAIN

ANTICLINORIUM

SURFACE

FEET

SEA LEVEL

1,000

2,000

1,000

2,000

A A' FEET

SEA LEVEL

1,000

2,000

3,000

1,000

2,000

3,000

4,000 4,000

1,000 feet=305 meters

Surficial deposits are not shown

NO VERTICAL EXAGGERATION

Om

Dm Db

Ojo

Sw Sw Sto Df Df Dmc Dfl

Dm

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BOBCAT TRL

U.S. ROUTE 50

U.S. ROUTE 50

N HAYFIELD RD

Great North

Mountain

Hayfield

DESCRIPTION OF MAP UNITS

Alluvium and floodplain deposits (Quaternary)—Clay, silt, sand, and 

gravel underlying floodplains along most streams; composed of 

light-olive-gray (5Y 5/2), yellowish-gray (5Y 7/2), and paleyellowish-orange (10YR 8/6) to dark-yellowish-orange (10YR 6/6), 

well-bedded to crudely bedded sand and silty clay. Pebble-size 

(4–64 millimeter) fragments of sandstone, siltstone, quartzite, and 

weathered shale are scattered throughout. Thickness ranges up to 

20 feet (ft) (6 meters [m])

Debris flow deposits (Quaternary?)—Clay, silt, sand, and boulders 

filling valleys on the slopes of Great North Mountain; composed of 

light-olive-gray (5Y 5/2), yellowish-gray (5Y 7/2), and paleyellowish-orange (10YR 8/6) to dark-yellowish-orange (10YR 6/6), 

chaotic to crudely bedded sand and silty clay, with boulders 

(angular to subrounded) of sandstone and quartzite scattered 

throughout. Thickness ranges up to 30 ft (9 m)

Hampshire Formation (Upper Devonian) (Darton, 1892)—Grayishred (10R 4/2), brownish-gray (5YR 4/1), dusky-red (5R 3/4), and 

dark-reddish-brown (10R 3/4), fine- to medium-grained, mediumto thick-bedded sandstone, shale, mudstone, and siltstone, with 

sparse plant fossils. The unit contains a few greenish-gray (5GY 6/1) 

to light-olive-gray (5Y 5/2) sandstones up to 10 ft (3 m) thick. Best 

exposed in the trough of the Mount Pleasant syncline along U.S. 

Route 50. The base of the Hampshire Formation is placed at the 

bottom of the first grayish-red (10R 4/2), cross-bedded, fluvial 

channel sandstone above the highest yellowish-gray (5Y 7/2) to 

light-olive-gray (5Y 5/2) fossiliferous sandstone, siltstone, and 

shale of the underlying Foreknobs Formation. Where the 

sandstone is not well exposed, this contact is inferred to be 

gradational and placed at the first occurrence of nonmarine red 

beds occurring in the sequence above fossiliferous sandstones, 

siltstones, and shales of the Foreknobs Formation. The top of the 

Hampshire Formation is not present in the quadrangle; however, 

the thickness of the formation in Frederick County is estimated to 

be as much as 3,600 ft (1,100 m) by Butts and Edmundson (1966), 

with less than 1,700 ft (520 m) exposed in the quadrangle

Foreknobs Formation (Upper Devonian) (Dennison, 1970)—The 

Foreknobs Formation (formerly the Chemung Formation, redefined 

by Dennison, 1970) consists of sequences of fossiliferous, marine 

sandstones, siltstones, and shales composed chiefly of 

yellowish-gray (5Y 7/2), brownish-gray (5YR 4/1) to 

light-olive-gray (5Y 5/2), greenish-gray (5GY 6/1), and grayish-red 

(5R 4/2), yellowish-gray (5Y 7/2) to light-olive-gray (5Y 5/2) 

weathering, thin- to medium-bedded, thick-bedded to massive, 

interbedded sandstone, siltstone, and shale, and some thin beds of 

conglomerate. The most common invertebrate fossils are 

brachiopods and crinoids, and plant fragments are also found in the 

upper portion of the formation. The top 200 to 300 ft (60 to 90 m) 

of fossiliferous, greenish-gray (5GY 6/1) sandstone, siltstone, and 

shale are interbedded with nonmarine red beds. Packages consisting 

of 3- to 10-ft (1- to 3-m)-thick, massive sandstone interbedded with 

siltstone and shale hold up two ridges that are mappable units 

throughout the quadrangle. The thicknesses and number of 

sandstone beds within each ridge-forming unit are variable. The 

upper ridge-forming unit (Dfu) consists of five to six beds of 

resistant sandstone that form a prominent ridge in the upper part of 

the formation; locally two or more masses form distinct ridges. The 

lower ridge-forming unit (Dfl) consists of three to four 

thick-bedded, resistant sandstones, interbedded with siltstone and 

shale that form a prominent ridge at the base of the formation. The 

interval between the two ridge-forming units consists of thin- to 

medium-bedded sandstone, siltstone, and shale that generally 

occupies the drainage area between the two ridges, and is 

commonly not well exposed. Dennison (1970) defined the 

Foreknobs and Scherr Formations within the Greenland Gap Group 

along the Allegheny structural front at Scherr, West Virginia; 

however, attempts to map boundaries between members of the 

Foreknobs Formation as proposed by Dennison (1970) were 

unsuccessful, and there is no mappable Scherr Formation present in 

the Hayfield quadrangle. The lower contact with the Brallier 

Formation is placed at the first occurrence of massive sandstone 

greater than 6 ft (2 m) thick, with quartz pebble conglomerate or 

centimeter (cm)-size clasts of sandstone, siltstone, and shale often 

observed within the sandstone. The thickness of the Foreknobs 

Formation in the Hayfield quadrangle is approximately 1,900 ft 

(580 m), but is 2,500 to 2,800 ft (760 to 850 m) in Frederick County

Brallier Formation (Upper Devonian) (Butts, 1918)—Medium-darkgray (N 4) to dark-gray (N 3), greenish-gray (5GY 6/1), lightolive-gray (5Y 5/2) to light-brownish-gray (5YR 6/1) weathering, 

thin- to medium-bedded, micaceous and siliceous, sparsely 

fossiliferous, interbedded shale, siltstone, and sandstone. 

Sandstone beds, 2 to 6 inches (in.) (5 to 15 cm) thick become more 

abundant near the top of the formation; occasional beds may be up 

to 2 ft (60 cm) thick. Shale interbedded with siltstone up to 3 in. 

(7.5 cm) thick make up the bulk of the formation. Generally 

unfossiliferous, but distinct thin fossil hashes composed mainly of 

brachiopods and crinoids occur at the base of isolated, 

planar-bedded sandstone beds, primarily in the upper half of the 

formation. Attempts to map the Scherr Formation (Dennison, 

1970) were unsuccessful, as there is no distinctive lithologic 

boundary between the Scherr (if present) and Brallier Formations 

in the Hayfield quadrangle. The contact with the underlying 

Mahantango Formation is placed just above a ridge-forming 

sandstone and siltstone unit, the informal Clearville member 

(Dmc). A regional unconformity is present above the Clearville 

member. The thickness of the Brallier ranges from 1,250 to 1,800 ft 

(380 to 550 m) in Frederick County (Butts and Edmundson, 1966), 

and is approximately 1,300 ft (400 m) in the Hayfield quadrangle

Mahantango Formation (Middle Devonian) (Willard, 1935)—Darkgray (N 3) to olive-gray (5Y 4/1), medium-gray (N 5), mudstone, 

siltstone, and shale; minor very fine grained, micaceous, brown to 

olive-gray sandstone is locally present. Mudstone, sand, and shale, 

locally massive, with hackly to crumbly weathering and containing 

fossiliferous layers interbedded with barren zones make up the 

bulk of the formation. Bedding is often obscured by anastomosing 

and pencil cleavage fractures in the more massive siltstones and 

mudstones. At the top of the formation, a medium-gray (N 5) to 

medium-dark-gray (N 4), fossiliferous siltstone and sandstone, 

commonly massive, forms the informal Clearville (Dmc) member 

of the Mahantango Formation (Jolley, 1983; original usage by 

Cate, 1963). This is a prominent ridge-forming unit, approximately 

100 to 180 ft (30 to 50 m) thick. A complete exposed section of the 

informal Clearville sandstone occurs at the intersection between 

Highway 50 and State Route 614 and was measured to be 130 ft 

(40 m) thick (Jolley, 1983). In the middle to lower third of the 

formation, another mappable, ridge-forming unit consists of 

medium-dark-gray (N 4) to dark-gray (N 3), locally calcareous, 

fossiliferous siltstone and thick-bedded to massive silty mudstone, 

estimated to be 165 to 250 ft (50 to 80 m) thick. This unit is 

believed to be equivalent to the Chaneysville siltstone (Dmch) 

member (Willard, 1935). The lower contact between the 

Mahantango Formation and the Marcellus Shale is marked by an 

unnamed ridge-forming siltstone bed approximately 20 ft (6 m) 

thick at the base of the Mahantango; this bed is well exposed along 

the creek that parallels the southwest side of Highway 50, about 

1,500 ft (460 m) southeast of the intersection of Highway 50 and 

State Route 600 at Hayfield. The total thickness of the Mahantango 

Formation in Frederick County is approximately 1,100 to 1,350 ft 

(340 to 410 m) (Butts and Edmundson, 1966)

Marcellus Shale (Middle Devonian) (Hall, 1839)—Dark-gray (N 3) to 

grayish-black (N 2), thinly laminated, fissile, micaceous shale; 

weathers dusky yellowish-gray (5Y 8/1) into thin platy chips. 

Locally contains thin, discontinuous beds and nodules of dark-gray 

(N 3), argillaceous limestone. The base of the Marcellus is marked 

by the Tioga Ash Bed (Harris and others, 1994) observed in 

outcrop along Highway 50 immediately east of the intersection 

with State Route 600. Thickness ranges from 150 to 300 ft (50 to 

90 m) in the Hayfield quadrangle, and up to 500 ft (150 m) in 

Frederick County (Butts and Edmundson, 1966)

Needmore Shale (lowest Middle and Lower Devonian) (Harris and 

others, 1994) (Willard, 1939)—Dark-greenish-gray (5GY 4/1) to 

olive-gray (5Y 4/1), fossiliferous, partly calcareous shale. At the 

top of the formation, as many as 12 thin (10-cm) limestone beds 

occur that are intercalated with black shale similar in character to 

that of the overlying Marcellus Shale. Several of these limestone 

beds are composed of brachiopod coquinas and are well exposed 

at the village of Hayfield at the intersection between Highway 50 

and State Route 600. Black shale at the base of the Needmore may 

be equivalent to the Beaver Dam Shale Member (Willard, 1939). 

The base of the Needmore is placed at the top of the coarse, 

fossiliferous and calcareous sandstone of the underlying Oriskany 

Sandstone; the contact is abrupt, representing the regional 

Wallbridge unconformity (Cate, 1963). Thickness ranges from 

140 to 175 ft (40 to 50 m)

Marcellus Shale and Needmore Shale undivided (Middle and Lower 

Devonian)—The Marcellus and Needmore Shales are mapped as a 

single unit along the northwest slope of Little North Mountain in 

Virginia and West Virginia; also shown in cross section A–A' at 

depth and in cross section B–B'

Lower Devonian and upper Silurian, undivided—Occurring along 

the northwest slope of Little North Mountain, this unit includes the 

Lower Devonian Oriskany Sandstone and upper Helderberg Group 

limestones, the Lower Devonian and uppermost Silurian Keyser 

Formation of the lower Helderberg Group, and the upper Silurian 

Tonoloway Limestone. Approximately 800 ft (240 m) thick, but 

likely thinned by faulting along the North Mountain fault zone. 

Shown at depth in cross sections A–A' and B–B'

Oriskany Sandstone (Lower Devonian) (Hall, 1839)—Light-gray (N 7)

to yellowish-gray (5Y 8/1), fine- to coarse-grained sandstone, 

often friable when weathered, containing molds of brachiopods. 

Thins from west to east; its thickness is less than 20 ft (6 m) 

along the northwest slope of Little North Mountain (mapped as 

part of unit DSls), but up to 100 ft (30 m) in the northwestern part 

of the quadrangle

Helderberg Group, excluding the Keyser Limestone (Lower 

Devonian) (Conrad, 1839)—The upper Helderberg Group units in 

Frederick County were mapped by Butts and Edmundson (1966) to 

include the Coeymans and New Scotland Limestones (Clarke and 

Schuchert, 1899). The nomenclature of these units has since been 

revised by Head (1974) to be the New Creek Limestone 

(Coeymans biostratigraphic equivalent) and the Corriganville 

Limestone (New Scotland Limestone biostratigraphic equivalent). 

Poor exposure of these upper Helderberg Group units in the 

Hayfield quadrangle precluded separation of these formations on 

the map; however, description of these units is provided from a 

few exposures. The New Creek Limestone consists of light-gray 

(N 7), coarse-grained, massive, crinoidal limestone approximately 

10 to 20 ft (3 to 6 m) thick. The Corriganville Limestone consists 

of grayish-blue (5PB 5/2) to dark-gray (N 3), finely crystalline, 

cobbly weathering, cherty, silty limestone. Butts and Edmundson 

(1966) reported a thickness of approximately 100 to 140 ft (30 to 

40 m) of the Corriganville in Frederick County; however, this 

would have included the thickness of the Licking Creek Limestone 

of Swartz (1939). The Licking Creek Limestone may be present in 

the Hayfield quadrangle, but it was not recognized owing to poor 

exposure and cover by talus blocks of the adjacent Oriskany 

Sandstone. Total thickness of the Helderberg Group, excluding the 

Keyser Limestone, is approximately 100 to 140 ft (30 to 40 m) in 

the quadrangle

Keyser Limestone of the lower Helderberg Group (Lower Devonian 

and uppermost Silurian) (Swartz, 1913)—Light-gray (N 7) to 

medium-gray (N 5), fine-grained, thin- to medium-bedded, 

fossiliferous limestone. The upper part of the Keyser Limestone is 

mostly thin-bedded, silty, contains some nodular beds, and is partly 

gradational with the overlying Corriganville Limestone; the lower 

part contains nodular beds that weather to small, lenticular pieces 

that accumulate on weathered outcrops. The Keyser Limestone is 

dated latest Silurian and Early Devonian based on conodont 

biostratigraphy (Denkler and Harris, 1988; Harris and others, 

1994). The base is placed at the bottom of the lowest nodularweathering limestone. The thickness is estimated to be 200 to 250 ft 

(60 to 80 m) in the quadrangle

Tonoloway Limestone (upper Silurian) (Ulrich, 1911)—Light-gray 

(N 7) to dark-gray (N 3), generally laminated to thin-bedded, 

fossiliferous (ostracods and stromatoporoids are common) 

limestone and carbonate mudstone, with minor argillaceous 

calcarenite, calcareous sandstone, and dolomite. Mudcracks and 

light-gray (N 7) laminae in lime mudstone are characteristic of 

most of the unit. The base is placed at top of the informal Tavenner 

sandstone member of the underlying Wills Creek Formation. Good 

exposure of this contact occurs along Highway 50 on the west limb 

of the Tavenner Ridge anticline. The thickness of the Tonoloway in 

Frederick County is reported to be as much as 500 ft (150 m) by 

Butts and Edmundson (1966), and is approximately 300 ft (90 m) 

thick in the Hayfield quadrangle

Wills Creek, Bloomsburg, and McKenzie Formations, undivided 

(upper Silurian)—Mapped along the northwest slope of Little 

North Mountain; shown in cross section A–A' at depth and in cross 

section B–B'

Wills Creek Formation (upper Silurian) (Uhler, 1905)—Moderatereddish-brown (10R 4/6), greenish-gray (5GY 6/1), and dark-gray 

(N 3), calcareous shale and sandstone containing interbedded 

argillaceous, laminated, carbonate mudstone; occasional pure 

limestones containing very fine quartz sand and lenses of red 

mudstone and shale throughout. The top of the formation is marked 

by the gray, hard, 10-ft (3-m)-thick, informal Tavenner sandstone 

member (not mapped separately) of Butts and Edmundson (1966, 

p. 46–47). The thickness of the Wills Creek formation ranges from 

300 to 600 ft (90 to 180 m) in the quadrangle

Bloomsburg Formation (upper Silurian) (White, 1883)—Grayish-red 

(10R 4/2) to moderate-reddish-brown (10R 4/6), fine- to mediumgrained, thin- to thick-bedded sandstone, siltstone, mudstone, and 

shale; the bulk of the formation consists of hematite-cemented 

quartz sandstone and reddish-brown mudstone. The thickness 

ranges from 150 to 400 ft (50 to 120 m) in the quadrangle

McKenzie Formation (upper Silurian) (Ulrich, 1911)—Medium-gray 

(N 5) to light-olive-gray (5Y 6/1), platy, calcitic shale; contains 

some red sandstone and locally yellowish-gray (5Y 8/1) shale near 

lower contact. Base of the unit is placed at the top of the 

underlying hard gray sandstone of the Keefer Sandstone. The 

thickness is approximately 200 ft (60 m) in the quadrangle (Butts 

and Edmundson, 1966), but the exposure belt on the southeast side 

of Great North Mountain is thickened by intra-formational folding

Keefer Sandstone and the Rose Hill Formation, undivided (upper 

Silurian)—Mapped along the northwest slope of Little North 

Mountain; shown in cross section A–A' at depth and in cross 

section B–B'

Keefer Sandstone (upper Silurian) (Stose and Swartz, 1912)— 

Medium-gray (N 5) to white (N 9), crossbedded sandstone and 

orthoquartzite in the upper part with fine-grained, thin-bedded 

sandstone and sandy shale intervals in the lower part. The Keefer is 

at least 30 to 50 ft (9 to 15 m) thick

Rose Hill Formation (upper Silurian) (Swartz, 1923)—Grayish-red 

(10R 4/2) sandstone; brownish-gray (5YR 4/1) shale and sandy 

shale; and hematite-cemented, grayish-red (10R 4/2) sandstone 

interbedded with olive-gray (5Y 4/1) sandstone. Ostracods and 

brachiopods are abundant. Base placed at the top of the underlying 

white quartzite of the Tuscarora Sandstone. Thickness in Frederick 

County is about 350 ft (110 m) as reported by Butts and 

Edmundson (1966), but the exposure belt on the southeast side of 

Great North Mountain in the Hayfield quadrangle is thickened by 

intra-formational folding

Tuscarora Sandstone (lower Silurian) (Darton and Taff, 1896)— 

White (N 9) to pinkish-gray (5YR 8/1), medium- to coarse- grained, 

medium- to thick-bedded sandstone to orthoquartzite; locally 

conglomeratic with quartz pebbles as much as 2 cm in diameter. A 

hard, erosion-resistant, ridge-forming unit. The base of the 

formation is placed at the top of the highest red bed of the 

underlying Juniata Formation. Butts and Edmundson (1966) 

reported a thickness of approximately 300 ft (90 m) within 

Frederick County

Juniata Formation and Oswego Sandstone, undivided (Upper 

Ordovician) (Darton and Taff, 1896; Vanuxem, 1842; 

respectively)—Moderate-red (5R 4/6), thin-bedded and 

crossbedded, arkosic sandstone and shale (Juniata) underlain by 

greenish-gray (5GY 6/1), coarse-grained, thick-bedded sandstone 

and conglomerate interbedded with sandstone (Oswego). Base of 

the unit along southeast slope of Little North Mountain is faulted 

out. Total thickness of combined units reported to range from 

150 to 300 ft (50 to 90 m) (Butts and Edmundson, 1966)

Martinsburg Formation (Upper and Middle Ordovician) (Geiger 

and Keith, 1891)—Interbedded shale and lesser graywackesiltstone and graywacke-sandstone. Shale, medium- gray (N 5) to 

dark-gray (N 3) and light-olive-gray (5Y 5/2), grayish-orange 

(10YR 7/4) and dark-yellowish-orange (10YR 6/6) weathering, 

commonly silty, and generally noncalcareous. Sandstone and 

siltstone, medium-gray (N 5), grayish-orange (10YR 7/4) 

weathering, very fine grained to fine-grained, commonly graded, 

lenticular, slightly calcareous to noncalcareous. Many small-scale 

crossbeds occur in sandstones. Graywacke is more abundant and 

thicker bedded higher in the unit. The Martinsburg Formation is 

only partially exposed and occurs as a fault slice in the North 

Mountain fault zone. Maximum thickness in Frederick County 

was estimated to be about 4,000 ft (1,200 m) by Butts and 

Edmundson (1966)

New Market Limestone (Middle Ordovician) (Cooper and Cooper, 

1946)—Limestone, medium-gray (N 5), light gray-weathering, 

thick-bedded, micritic, fenestral. Lower 3 ft (1 m) is medium-gray 

(N 5), thin-bedded, dolomitic limestone and light-gray (N 7) 

calcareous dolostone. Exposed only in a faulted horse block 

southeast of Little North Mountain in the southwest corner of the 

quadrangle. Estimated to be between 80 and 200 ft (24 to 60 m) 

thick by Butts and Edmundson (1966) in Frederick County

Conococheague Limestone (Lower Ordovician and Upper 

Cambrian) (Stose, 1908)—Interbedded cyclical limestone, 

dolostone, and sandstone. Limestone, medium-gray (N 5), finegrained, thin- to medium-bedded; includes intraformational 

conglomerate, algal bioherms, intertidal limestone and dolomitic 

stringers (“ribbon rock”), and oolite. Dolostone and dololaminite, 

light-gray (N 7), fine-grained, medium-bedded. Sandstone, lightgray (N 7) to tan, reddish-weathering, medium- to coarse-grained, 

calcareous. The lower 200 ft (60 m) consist of the Big Spring 

Station Member (not mapped separately) of Wilson (1952), which 

consists of gray to tan, reddish-weathering, coarse-grained, 

calcareous sandstone; medium-gray (N 5), fine-grained limestone 

with intraformational conglomerate; and light-gray (N 7), finegrained dolostone. Sandstone beds occur at the base of the formation 

and in two ridge-forming packages in the upper part of the 

formation. Thickness ranges from 2,200 to 2,600 ft (690 to 810 m), 

and the base of the unit is placed below the first calcareous 

sandstone of the Big Spring Station Member

Elbrook Formation (Middle and Lower Cambrian) (Stose, 

1906)—Interbedded limestone, dolostone, and shale. Limestone, 

medium-gray (N 5), fine- to medium-grained, thin- to mediumbedded; contains algal bioherms, intraformational conglomerates, 

and mottled beds. Dolostone, light- to medium-gray (N 7 to N 5), 

yellowish-weathering, fine-grained, medium-bedded. Shale, gray, 

yellowish-weathering, dolomitic. Lower part of formation is cut 

out by the North Mountain fault zone. At least 2,300 ft (720 m) 

thick, but only partially exposed in the Hayfield quadrangle

EXPLANATION OF MAP SYMBOLS

Contact—Approximately located; dotted where concealed

Thrust fault—Sawteeth on upper plate. Approximately located; dotted 

where concealed

FOLDS

[Showing trace of axial surface, direction of dip of limbs, and direction of plunge

where known or inferred]

Anticline

Syncline

Plunging anticline

Plunging syncline

Doubly plunging anticline

Doubly plunging syncline

Overturned anticline

PLANAR FEATURES

[Symbols may be combined; point of observation is at intersection of multiple symbols]

Strike and dip of beds

Inclined

Vertical

Overturned

Horizontal

Strike and dip of cleavage

Inclined

Vertical

Strike and dip of joints

Inclined

Vertical

OTHER FEATURES

Spring—Tail indicates direction of flow

Closed depression

Large—Greater than 10,764 square feet (1,000 square meters)

Small—Less than or equal to 10,764 square feet (1,000 square meters)

Conodont fossil locality—Sample information is linked to locality in the

digital geodatabase

DISCUSSION

The Hayfield 7.5-minute quadrangle is located within the Valley and Ridge 

physiographic province of northern Virginia. The quadrangle includes the 

topographical lowland area of the northern Great Valley to the southeast, the 

narrow ridge of Little North Mountain along the western edge of the Great Valley, 

and the broad region of elongated valleys and ridges east of Little North Mountain 

(fig. 1). The most prominent physiographic feature within the quadrangle is Great 

North Mountain, which extends across the northwestern portion of the quadrangle.

STRATIGRAPHY

All exposed bedrock units are Paleozoic sedimentary rocks ranging from 

Middle Cambrian to Late Devonian, approximately 513 to 359 Ma (fig. 1). Butts 

and Edmundson (1966) previously mapped Frederick County, Va., at a scale of 

1:62,500. Detailed stratigraphic descriptions are included in that report, but 

revisions to stratigraphic nomenclature of certain units such as the lower Silurian 

Rose Hill Formation and Keefer Sandstone (formerly Clinton Formation), the 

Lower Devonian New Creek and Corriganville Limestones of the Helderberg 

Group (formerly Coeymans and New Scotland Limestones, respectively), the 

Lower to Middle Devonian Needmore Shale (formerly Onondaga Formation), the 

Middle Devonian Mahantango Formation (formerly Hamilton Formation), and the 

Upper Devonian Foreknobs Formation (formerly Chemung Formation) have been 

made since publication of the report by Butts and Edmundson (1966) and are 

presented herein (see “Description of Map Units” section). 

The clastic and carbonate sedimentary strata in the quadrangle reflect 

nearshore and offshore marine and deltaic depositional environments. The deposits 

indicate minor sea level transgression and regression cycles along a passive 

continental margin during the Late Cambrian to Middle Ordovician, and major sea 

level changes resulting from tectonic uplift during the Late Ordovician Taconian 

orogeny and the Middle to Late Devonian Acadian orogeny. Depositional 

environments include (from oldest to youngest) (1) a broad, shallow epeiric marine 

platform represented by the carbonate rocks of Middle Cambrian to Middle 

Ordovician age; (2) Late Ordovician marine shelf, ramp, and basin deposits of shale 

and turbiditic flysch; (3) Late Ordovician, Silurian, and Early Devonian nearshore 

marine sandstones, limestones, and shales; and (4) Early to Late Devonian marine 

basin, nearshore marine, and fluvial-deltaic siliciclastic shales, siltstones, and minor 

sandstones. These strata account for about 20,000 feet (ft) of section.

Topographic ridges in the quadrangle are primarily held up by sandstones and 

orthoquartzites that are relatively resistant to erosion. Great North Mountain and 

Little North Mountain are held up by the Tuscarora Sandstone (Stu), with lesser 

ridges on the flanks held up by the Keefer Sandstone (Sk). Chert-bearing carbonate 

units of the Helderberg Group (Dhl) as well as the Oriskany Sandstone (Do) hold up 

Flint Ridge. The informal Tavenner sandstone (Butts and Edmundson, 1966) of the 

Wills Creek Formation (Sw) forms a low ridge that can be traced between Flint 

Ridge and the southeast flank of Great North Mountain. Lower ridges west of Little 

North Mountain are underlain by sandstones in the Mahantango (Dm) and 

Foreknobs (Df) Formations. East of Little North Mountain, more subtle ridges are 

held up by limestone and shaly dolomite of the Elbrook Formation (_e) and thin 

sandstone beds within the Conococheague Limestone (O_c).

Surficial materials include unconsolidated alluvium, colluvium, debris flow, 

and terrace deposits that are assumed to be of Quaternary age. Alluvium (Qa) was 

mapped along the larger streams; locally, some low alluvial terraces exist but have 

not been broken out within this unit. Debris flow deposits (Qdf) were mapped 

where recognized in the lidar-derived topographic imagery on the flanks of Great 

North Mountain. Colluvium (not mapped separately) covers most of the steeper 

slopes and fills the bottoms of many of the mountain hollows, and is composed 

mainly of sandstone boulders and cobbles, and fragments of chert.

STRUCTURE

Deformation of the bedrock in the Hayfield quadrangle took place primarily 

during the late Paleozoic Alleghanian orogeny when the North American continent 

collided with the continents of Africa and Europe, forming the supercontinent 

Pangea. Compressive forces caused by the continental collision resulted in folding 

and faulting of the sedimentary rock strata, with northwestward tectonic transport. 

The breakup of Pangea occurred during the Mesozoic Era owing to continental 

rifting; however, deformation from this time period is not definitively evident in the 

rocks of the Hayfield quadrangle.

The quadrangle lies across the Great North Mountain anticlinorium (Butts and 

Edmundson, 1966) and includes portions of several other regional folds such as the 

Mount Pleasant syncline, the Tavenner Ridge anticline, the Hayfield Ridge 

syncline, the Tunnel Ridge syncline, and the Sand Ridge anticline. Most folds verge 

to the northwest, reflecting the tectonic transport direction, and trend approximately 

28° to 30° to the northeast with gentle plunges to either the north-northeast or 

south-southwest. The Mount Pleasant syncline, centrally located within the 

quadrangle, is a doubly-plunging syncline with more steeply dipping beds on the 

southeastern limb. This is a regional syncline that spans all of Frederick County 

(Butts and Edmundson, 1966).

The North Mountain fault zone, spanning across the southeastern part of the 

quadrangle, forms the western border of the Shenandoah Valley in northern Virginia 

and is a series of northeast-trending thrust faults with multiple splays that separate 

the Silurian and Devonian shales, siltstones, and sandstones from the Cambrian and 

Ordovician carbonate rocks and shales (fig. 1). In the Hayfield quadrangle, a horse 

of Middle Ordovician New Market Limestone was raised between two of the thrust 

splays in the exposure of the fault zone furthest to the southwest. The North 

Mountain fault zone extends to the northwest side of Little North Mountain and 

brings Silurian and Lower Devonian rocks onto Middle Devonian shales of the 

Marcellus and Needmore Shales. Interpretation of the fault structure in cross 

section B–B' followed that of Orndorff (2012). Irregular outcrops of the Tuscarora 

Sandstone within the North Mountain fault zone resulted from cross-strike faulting 

rather than from thinning of sedimentary strata (Giles, 1942).

A lower hemisphere equal-area projection of the poles to planes of all joints 

measured in the quadrangle is shown in figure 2, which illustrates general extension 

in a northeast-southwest direction in response to the regional thrust transport 

direction to the northwest. However, the overall distribution of joints is less regular, 

as seen in the rose diagram of joint plane azimuths shown in figure 3. The mean 

vector of the rose diagram highlights the regional transport direction to the 

northwest, but joints also trend northeast-southwest and north-south, likely as 

conjugate sets to the primary joint trend.

REFERENCES CITED

Butts, Charles, 1918, Geologic section of Blair and Huntingdon Counties, 

central Pennsylvania: American Journal of Science, 4th ser., v. 46, no. 273, 

p. 523–537. [Also available at https://doi.org/10.2475/ajs.s4-46.273.523.]

Butts, Charles, and Edmundson, R.S., 1966, Geology and mineral resources of 

Frederick County: Virginia Division of Mineral Resources Bulletin 80, 142 p., 

2 pls. [Also available at https://www.dmme.virginia.gov/commerce/ 

ProductDetails.aspx?ProductID=1429.] 

Cate, A.S., 1963, Lithostratigraphy of some Middle and Upper Devonian rocks in 

the subsurface of southwestern Pennsylvania, in Shepps, V.C., ed., 

Symposium on Middle and Upper Devonian stratigraphy of Pennsylvania and 

adjacent States: Pennsylvania Geological Survey General Geology Report 

G39, p. 229–240. [Also available at https://archive.org/details/ 

symposiumonmiddl00shep.]

Clarke, J.M., and Schuchert, Charles, 1899, The nomenclature of the New York 

series of geological formations: Science, v. 10, no. 259, p. 874–878. [Also 

available at https://doi.org/10.1126/science.10.259.874.]

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New York Geological Survey Annual Report, v. 3, p. 57–66.

Cooper, B.N., and Cooper, G.A., 1946, Lower Middle Ordovician stratigraphy 

of the Shenandoah Valley, Virginia: Geological Society of America 

Bulletin, v. 57, no. 1, p. 35–114, 3 pls. [Also available at https://doi.org/ 

10.1130/0016-7606(1946)57[35:LMOSOT]2.0.CO;2.]

Darton, N.H., 1892, Notes on the stratigraphy of a portion of central Appalachian 

Virginia: The American Geologist, v. 10, p. 10–18. [Also available 

https://hdl.handle.net/2027/uc1.31822009425760.]

Darton, N.H., and Taff, J.A., 1896, Description of the Piedmont sheet, in Piedmont 

folio, West Virginia-Maryland: U.S. Geological Survey Geological Atlas of the 

United States, no. 28, 6 p. [Also available at https://pubs.er.usgs.gov/ 

publication/gf28.]

Dennison, J.M., 1970, Stratigraphic divisions of Upper Devonian Greenland Gap 

Group (“Chemung Formation”) along Allegheny Front in West Virginia, 

Maryland, and Highland County, Virginia: Southeastern Geology, v. 12, no. 1, 

p. 53–82.

Denkler, K.E., and Harris, A.G., 1988, Conodont-based determination of the 

Silurian-Devonian boundary in the Valley and Ridge province, northern and 

central Appalachians, chap. B of Sando, W.J., ed., Shorter contributions to 

paleontology and stratigraphy: U.S. Geological Survey Bulletin, v. 1837, 

p. B1–B13, 1 pl. [Also available at https://pubs.er.usgs.gov/publication/b1837.]

Geiger, H.R., and Keith, Arthur, 1891, The structure of the Blue Ridge near 

Harper’s Ferry (with discussion by C.D. Walcott and C.H. Hitchcock): 

Geological Society of America Bulletin, v. 2, no. 1, p. 155–164. [Also 

available at https://doi.org/10.1130/GSAB-2-155.]

Giles, A.W., 1942, Structure of Little North Mountain of the north-central 

Appalachians: The Journal of Geology, v. 50, no. 8, p. 961–980. [Also 

available at https://doi.org/10.1086/625102.]

Hall, James, 1839, Third annual report of the fourth geological district of the State 

of New York: New York Geological Survey Annual Report, v. 3, p. 287–319.

Harris, A.G., Stamm, N.R., Weary, D.J., Repetski, J.E., Stamm, R.G., and Parker, 

R.A., 1994, Conodont color alteration index (CAI) map and conodont-based 

age determinations for the Winchester 30' × 60' quadrangle and adjacent areas 

Virginia, West Virginia, and Maryland: U.S. Geological Survey Miscellaneous 

Field Studies Map MF–2239, 40 p., scale 1:100,000. [Also available at 

https://pubs.er.usgs.gov/publication/mf2239.]

Head, J.W., 1974, Correlation and paleogeography of upper part of Helderberg 

Group (Lower Devonian) of central Appalachians: The American Association 

of Petroleum Geologists Bulletin, v. 58, no. 2, p. 247–259. [Also available at 

http://archives.datapages.com/data/bulletns/1974-76/data/pg/0058/0002/0200/

0247.htm.]

Jolley, R.M., 1983, The Clearville siltstone member of the Middle Devonian 

Mahantango Formation in parts of Pennsylvania, Maryland, West Virginia, 

and Virginia: University of North Carolina at Chapel Hill, M.S. thesis, 192 p., 

3 sheets.

Orndorff, R.C., 2012, Fold-to-fault progression of a major thrust zone revealed in 

horses of the North Mountain fault zone, Virginia and West Virginia, USA: 

Journal of Geological Research, v. 2012, article 294093, 13 p., accessed 

August 14, 2017, at https://doi.org/10.1155/2012/294093.

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Journal of Geology, v. 14, no. 3, p. 201–220. [Also available at https://doi.org/ 

10.1086/621298.]

Stose, G.W., 1908, The Cambro-Ordovician limestones of the Appalachian Valley 

in southern Pennsylvania: The Journal of Geology, v. 16, no. 8, p. 698–714. 

[Also available at https://doi.org/10.1086/621572.]

Stose, G.W., and Swartz, C.K., 1912, Description of the Pawpaw and Hancock 

quadrangles, in Pawpaw-Hancock folio, Maryland-West VirginiaPennsylvania: U.S. Geological Survey Geological Atlas of the United States, 

no. 179, 24 p. [Also available at https://pubs.er.usgs.gov/publication/gf179.]

Swartz, C.K., 1913, Correlation of the Lower Devonian, in Paleozoic Era—Lower 

Devonian: Maryland Geological Survey Systematic Report, p. 96–132. [Also 

available at http://speccol.msa.maryland.gov/pages/speccol/unit.aspx?speccol 

=6046&serno=1&item=33&subitem=-1.]

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of other areas, in Paleozoic Era—Silurian: Maryland Geological Survey 

Systematic Report, p. 183–232. [Also available at http://speccol.msa. 

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subitem=-1.]

Swartz, F.M., 1939, The Keyser Limestone and Helderberg Group, in Willard, 

Bradford, The Devonian of Pennsylvania: Pennsylvania Geological Survey, 

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details/devonianofpennsy00penn.]

Uhler, P.R., 1905, The Niagara period and its associates near Cumberland, 

Maryland: Maryland Academy of Science Transactions, v. 2, p. 19–26.

Ulrich, E.O., 1911, Revision of the Paleozoic systems: Geological Society of 

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the third geological district: Albany, N.Y., W. and A. White and J. Visscher, 

306 p.

White, I.C., 1883, The geology of the Susquehanna River region in the six counties 

of Wyoming, Lackawanna, Luzerne, Columbia, Montour, and Northumberland: 

Pennsylvania Geological Survey Report of Progress G7, 464 p. [Also available 

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available at https://doi.org/10.1130/GSAB-46-1275.]

Willard, Bradford, 1939, Middle and Upper Devonian, in Willard, Bradford, The 

Devonian of Pennsylvania: Pennsylvania Geological Survey, 4th ser., Bulletin 

G19, p. 131–377. [Also available at https://archive.org/details/ 

devonianofpennsy00penn.]

Wilson, J.L., 1952, Upper Cambrian stratigraphy in the central Appalachians: 

Geological Society of America Bulletin, v. 63, no. 3, p. 275–322. [Also available 

at https://doi.org/10.1130/0016-7606(1952)63[275:UCSITC]2.0.CO;2.]

Qa

Qdf

Dh

Df

Dfu

Dfl

Dm

Dmch

Dmc

Db

Dmr

Dn

Dmn

_e

O_c

On

Om

Ojo

Stu

Skr

Swbm

DSls

Do

Srh

Sk

Smk

Sb

Sw

Sto

DSk

Dhl

DEVONIAN

ORDOVICIAN

CAMBRIAN

SILURIAN

Unconformity

Dn

Do

Dhl

Dmr

Sto

Sw

Sb

DSk

Sk

Dmn

Swbm

DSls

Skr

Srh

Stu

Smk

Om

On

O_c

_e

Ojo

Db

Df

Dfu

Dfl

Dm

Dmc

Dmch

Dh

Qdf

CORRELATION OF MAP UNITS

Qa

QUATERNARY

Geologic Map of the Hayfield Quadrangle, Frederick County, Virginia

By

Daniel H. Doctor and Ronald A. Parker 

2018

Geology mapped by Parker (1992–93) and by Doctor (2007–15)

Lidar-derived elevation surface imagery by Doctor, 2015

Edited by Natalie Juda

Cartography by D. Paul Mathieux

Base from U.S. Geological Survey, 2016

Projection and 1,000-meter grid ticks, Universal Transverse 

Mercator, zone 17S. North American Datum of 1983 

(NAD83). World Geodetic System of 1984 (WGS84)

10,000-foot grid ticks based on Virginia coordinate system 

of 1983 (north zone)

.5 0

SCALE 1:24 000

1 1/2 0 1 MILE

1 KILOMETER

CONTOUR INTERVAL 20 FEET

NORTH AMERICAN VERTICAL DATUM OF 1988

MAGNETIC NORTH

APPROXIMATE MEAN

DECLINATION, 2018 TRUE NORTH

10°

ISSN 2329-132X (online)

https://doi.org/10.3133/sim3407

Any use of trade, product, or firm names in this publication 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

Digital files available at https://doi.org/10.3133/sim3407

Suggested citation: Doctor, D.H., and Parker, R.A., 2018, Geologic map of the Hayfield 

quadrangle, Frederick County, Virginia: U.S. Geological Survey Scientific Investigations 

Map 3407, scale 1:24,000, https://doi.org/10.3133/sim3407.

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3407

VIRGINIA

MAP LOCATION