N = 56; Size of largest petal = 8.9%

W E

N

S

Figure 3.—Equal area Rose diagram of joint orientations in the 

White Hall quadrangle. Petals represents joint azimuths binned in 

10o increments, dip to right of azimuth.

A

B

C

D

MAPPING RESPONSIBILITY

A,B - Lessing, Dean, and Kulander (1994); Parker, Doctor

B - Orndorff, Doctor

C - Parker, Doctor 

D - Doctor, Orndorff, Weary, Repetski

FORMATION and MEMBER LITHOLOGY

 APPROX.

THICKNESS

 (in feet)

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 Quartzite

Rose Hill Formation

Keefer Sandstone

Bloomsburg Formation

and

McKenzie Formation

Wills Creek Formation

Tonoloway Limestone

Helderberg Group

Oriskany Sandstone

Needmore Shale

Marcellus Shale

Mahantango Formation

Chaneysville Siltstone Member

Clearville Sandstone Member

Brallier Formation

Foreknobs Formation

lower ridge-forming unit 

upper ridge-forming unit

Alluvium and colluvium

Hampshire Formation

D E V O N I A N S I L U R I A N O R D O V I C I A N C A M B R I A N

Middle Upper Lower

Beekmantown Group

Middle Upper

Period

Stage

Fossils

2500+ ft

2800 ft

770 ft

1,200 ft

up to 700 ft

160 ft

500 ft

5000+ ft

100 ft

150 ft

250 ft

370 ft

130 ft

95–135 ft

400 ft

140–180 ft

300 ft

100 ft

100 ft

700 ft

1600–1800 ft

850 ft

380 ft

1100 ft

1700 ft

700 ft

500 ft

up to 850 ft

0–40 ft

Lower Upper Lower Upper Middle

Big Spring Station Member 295 ft

80 ft

Stickley Run Member

Alluvium and colluvium

Sandy or silty shale

Interbedded sandstone and siltstone

Interbedded siltstone and shale

Argillaceous or shaly sandstone

Clay or clay shale

Silt, siltstone, or shaly silt

Carbonaceous shale

Calcareous shale

Crossbedded sandstone

Cherty limestone

Limestone

LITHOLOGIC PATTERNS

Argillaceous or shaly limestone

Bedded sandstone

Fossiliferous clastic limestone

Nodular or irregularly bedded limestone

Conglomerate

Quartzite

Crossbedded subgraywacke

Interbedded limestone and shale

Dolomitic limestone

Cherty dolomite

Dolomite

Silty limestone

Sandy limestone

Sandy dolomite

Silty dolomite

Argillaceous or shaly dolomite

COMMONLY OCCURRING FOSSILS

Brachiopods

Gastropods

Corals

Bryozoans

Crinoids

Burrows

Ostracodes

Graptolites

Nautiloids

Trilobites

Conodonts

Stromatolites

Regional unconformity

Major fault zone

STRATIGRAPHIC COLUMN

EXPLANATION

WEST VIRGINIA

W. VA.

VA.

VIRGINIA

SM

SM

Om

Om

Om

Om

NORTH 

MOUNTAIN 

BLUE 

RIDGE 

FAULT 

PROVINCE 

ZONE 

Winchester

Strasburg

Harrisonburg

SM

DS

Om

Silurian through Mississippian rocks of the Valley and 

 Ridge Province 

Devonian and Silurian rocks of Massanutten Mountain

Upper and Middle Ordovician Martinsburg 

 Formation

Cambrian through Middle Ordovician rocks, mainly 

 carbonate

Neoproterozoic and Lower Cambrian rocks 

 of the Blue Ridge Province

SD

SD

VIRGINIA

MAP LOCATION

Anticline -- arrow indicates direction of plunge

Overturned anticline

Syncline -- arrow indicates direction of plunge

_O

Z_

Overturned syncline

Z_

WHITE HALL

QUADRANGLE

GREAT 

VALLEY 

PROVINCE 

_O

_O

_O

Z_

Z_

_O

FAULT

MOUNTAIN

SYNCLINE

GREAT NORTH

BAILEY FORD ANTICLINORIUM

MEADOW BRANCH SYNCLINORIUM

FAULT

MOUNT

MOUNTAIN

ANTICLINORIUM

PLEASANT

SYNCLINE

FAULT

NORTH

LITTLE

Thrust fault -- teeth on upthrown block

BACK

CREEK

APPLE

PIE

RIDGE

WELLTOWN

WELLTOWN FAULT

Strike-slip fault -- arrows indicate relative motion

FAULT

MOUNTAIN

ZONE

NORTH

Figure 1. -- General geologic map of the Great Valley Province in 

northern Virginia showing the location of the White Hall 7.5-minute 

quadrangle, and inset map of the White Hall quadrangle showing shaded 

relief and selected structural elements. Lithotectonic units on inset map: 

MS, Mississippian through Silurian rocks of Valley and Ridge Province;

_O, 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.

_O

_O

_O

SM

SM

SM

SM

Mountain

North

Little

W.VA.

MOUNTAIN 

MASSANUTTEN 

A

B

Figure 2. Seasonal photographs of focused internal drainage of surface water. Both sites A and B are labeled on the map and are located near thrust faults in the 

Cambrian-Ordovician carbonate units east of the North Mountain fault zone. Closed depressions (sinkholes) collect surface runoff during snowmelt, which ponds 

and infiltrates over the course of days to a few weeks. These depressions are normally dry in summer, as seen in summer (right) photo of site A.

GEOLOGIC MAP OF THE WHITE HALL QUADRANGLE, FREDERICK COUNTY, VIRGINIA, AND BERKELEY COUNTY, WEST VIRGINIA

By

Daniel H. Doctor, Randall C. Orndorff, Ronald A. Parker, David J. Weary, and John E. Repetski

2010

KARST FEATURES AND HYDROLOGY

 Karst refers to a type of terrain that develops due to solution of bedrock 

along groundwater flowpaths, resulting in voids at depth. Features typical of karst 

terrain include sinkholes and shallow closed depressions (dolines), sinking streams, 

springs, and caves. Karst development is pervasive in the Cambrian and Ordovician 

carbonate rocks in the northern Shenandoah Valley (Hubbard, 1983; Orndorff and 

Goggin, 1994). In the White Hall quadrangle karst development occurs in all of the 

carbonate rocks. Caves are not prevalent in the quadrangle; only one cave is known 

and it occurs within the middle limestone of the Elbrook Formation. The cave is a 

former phreatic passage extending down the dip of bedding for approximately 200 

ft, with ephemeral standing water at the bottom. Springs occur mainly near or on 

faults. It is noteworthy that several perennial springs in the quadrangle were found 

near the crest of Apple Pie Ridge, especially near zones of tight folding or to the east 

of southeast-dipping thrust faults. Most of these are smaller springs (<1 cubic foot 

per second), and several flow over the surface for a short distance before sinking 

again. The largest springs in the quadrangle are located within the Stonehenge 

Limestone, southeast of the village of Green Spring. Sinkhole development is 

concentrated along faults, along the axis of the Welltown syncline, and within the 

nose and axis of the Pumpkin Ridge anticline; however, sinkholes occur within all 

of the carbonate rock units, especially where the rocks have undergone locally 

intensified deformation through folding, faulting, or some combination (see also 

Hubbard, 1983). Along the North Mountain fault zone, sinkholes pond water as they 

collect surface runoff in the wet season, although they eventually drain (Fig. 2). 

Areas of low elevation formed within the carbonate rocks permit rapid internal 

drainage, and constitute zones of focused groundwater recharge.

REFERENCES CITED

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

Virginia Division of Mineral Resources Bulletin 80, 142 p., 1 map as plate, scale 1:62,500.

Dean, S.L., Lessing, Peter, and Kulander, B.R., 1994, Geology of North Mountain in eastern West 

Virginia [abs]: Geological Society of America, Abstracts with Program, v. 26, no. 4, p. 10.

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

Geology, v. 50, no. 8, p. 961–980.

Hubbard, D.A., Jr. 1983, Selected karst features of the northern Valley and Ridge province, Virginia: 

Virginia Division of Mineral Resources Publication 44, 1 map sheet, scale 1:250,000. 

Jolley, R.M., 1983, The Clearville Siltstone Member of the Middle Devonian Mahantango Formation 

in parts of Pennsylvania, Maryland, West Virginia, and Virginia: Chapel Hill, N.C., University of 

North Carolina, M.S. thesis, 192 p.

Lessing, P., Dean, S.L., and Kulander, B.R., 1994. Geology of the White Hall quadrangle, Berkeley 

County, West Virginia: West Virginia Geological and Economic Survey Open File Report OF–9406, 

10p., with 1 map sheet, scale 1:24,000.

Orndorff, R.C., 1988, Latest Cambrian and earliest Ordovician conodonts from the Conococheague and 

Stonehenge Limestones of northwestern Virginia: U.S. Geological Survey Bulletin 1837–A, 23 p.

Orndorff, R.C., 1992, Tectonic significance of cross-strike faults in the central Appalachian Great 

Valley of Maryland and West Virginia: Southeastern Geology, v. 32, no. 4, p. 197–214.

Orndorff, R.C., Epstein, J.B., and McDowell, R.C., 1999, Geologic map of the Middletown quadrangle, 

Frederick, Shenandoah, and Warren Counties, Virginia: U.S. Geological Survey Geologic Quadrangle 

Map GQ–1803, scale 1:24,000.

Orndorff, R.C., and Goggin, K.E., 1994, Sinkholes and karst-related features of the Shenandoah Valley 

in the Winchester 30' x 60' quadrangle, Virginia and West Virginia: U.S. Geological Survey Miscellaneous Field Studies Map MF–2262, scale 1:100,000.

Orndorff, R.C., Weary, D.J., and Parker, R.A., 2003, Geologic map of the Winchester quadrangle, 

Frederick County, Virginia: U.S. Geological Survey Open-File Report 2003–461, scale 1:24,000.

DISCUSSION

INTRODUCTION

 The White Hall quadrangle is located within the Valley and Ridge province 

of northern Virginia and the eastern panhandle of West Virginia. The quadrangle 

includes the physiographic regions 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. 

Early geologic mapping in the White Hall quadrangle was conducted by Butts and 

Edmundson (1966), who mapped the Frederick County, Va., portion at a scale of 

1:62,500. Lessing and others (1994) mapped the West Virginia portion of the 

quadrangle at a scale of 1:24,000. Dean and others (1994) and Lessing and others 

(1994) refer to the prominent curvilinear ridge extending into the northeast corner of 

the quadrangle as North Mountain, whereas Butts and Edmundson (1966) refer to it 

as Little North Mountain. Despite the label of North Mountain on the topographic 

base map, this ridge is referred to as Little North Mountain in this report to avoid 

confusion with Great North Mountain immediately to the southwest and to preserve 

continuity with the nomenclature of this feature as it extends farther south in 

Virginia. 

STRATIGRAPHY

 All exposed bedrock outcrops are sedimentary deposits of Paleozoic age 

ranging from the Middle Cambrian Period to Late Devonian Period, approximately 

515 to 365 Ma. These clastic and carbonate sedimentary strata reflect nearshore and 

offshore marine and deltaic depositional environments. The deposits indicate minor 

cyclic sea level transgression and regression along a passive continental margin 

during the Late Cambrian to Middle Ordovician Periods, to major sea level changes 

resulting from tectonic uplift during the Late Ordovician part of the Taconian 

orogeny. Depositional environments (from oldest to youngest) include (1) broad 

shallow marine shelf represented by the carbonate rocks of the Late Cambrian to 

Middle Ordovician Periods; (2) continental slope and foreland basin, represented by 

deposits of shale and turbiditic flysch in the Upper Ordovician; (3) nearshore 

marine, represented by sandstones, limestones, and shales of the uppermost 

Ordovician to lower Devonian; (4) marine basin and river delta, represented by 

siliciclastic shales, siltstones, and minor sandstones of the Early to Late Devonian 

Periods (Orndorff and others, 1999). These strata account for about 21,700 ft of 

section.

 Topographic ridges in the quadrangle are held up by the resistant 

sandstones and quartzites in the Tuscarora Quartzite (St) or Keefer Sandstone and 

Rose Hill Formation (Skr), as on Little North Mountain. Lower ridges west of Little 

North Mountain are underlain by sandstones in the Foreknobs (Df) or Mahantango 

(Dm) Formations. East of Little North Mountain, the prominent Apple Pie Ridge is 

held up by limestone and shaly dolomite of the Elbrook Formation (Єe) that has 

been thrust up along the Apple Pie Ridge fault. Other ridges in the carbonate units 

are held up by thin sandstone beds within the Conococheague Limestone (OЄc) or 

highly siliceous beds at the base of the Stonehenge Limestone (Os).

 Placement of contacts between the Lower Ordovician carbonate rock units 

were aided by the collection and identification of conodont fossils (Orndorff, 1988). 

On the east limb of the Welltown syncline the contacts between the Rockdale Run 

Formation (Or), Stonehenge Limestone, and Conococheague Limestone were 

placed using the conodont fossil assemblages found at the junction of State Route 

672 and Welltown Road, just south of Galilee Church. Conodont fossil assemblages 

also aided in placing contacts between carbonate units within the carbonate duplex 

along the North Mountain fault zone. 

 Surficial materials include unconsolidated alluvium, colluvium, and 

terrace deposits of Quaternary age, and local paleo-terrace deposits possibly of 

Tertiary age. Alluvium (Qa) was tentatively mapped along the larger streams; 

locally, low terraces may exist but have not been broken out within this unit. 

Colluvium (not mapped) covers most of the steeper slopes and fills the bottoms of 

many of the mountain hollows; it is composed mainly of quartzite and sandstone 

boulders and cobbles, or fragments of chert.

STRUCTURE

 Tectonic deformation of the bedrock in the White Hall quadrangle took 

place during the Alleghanian orogeny of the Late Paleozoic Era when the North 

American continent collided with the continents of Africa and Europe, forming the 

supercontinent Pangea. Erosion has predominated during the last 280 m.y., resulting 

in the present landscape. 

 The quadrangle lies across the northeast plunge of the Great North 

Mountain anticlinorium (Butts and Edmundson, 1966) and includes several other 

regional folds. Folds tend to verge to the northwest, reflecting the tectonic transport 

direction, and trend to the northeast approximately 28o to 30o 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 that has 

steeply dipping overturned beds on the east limb. This is the northernmost extent of 

a regional syncline that spans all of Frederick County (Butts and Edmundson, 

1966). To the north, the southernmost extent of the Bailey Ford anticlinorium 

plunges out southwestward into a complex series of synclines and anticlines lying 

parallel to the Mount Pleasant syncline. To the west and southwest, many 

northeast-plunging folds nose out and represent the northeastern extent of the Great 

North Mountain anticlinorium and the southwestern extent of the Meadow Branch 

synclinorium. To the southeast, the main folds are the Welltown syncline and the 

Pumpkin Ridge anticline; both plunge to the south. A notable anticline plunges to 

the northeast at the eastern edge of the map area and contains the only exposure of 

the Middle Ordovician rocks in the quadrangle. After being formed, this anticline 

subsequently was cut by faults having relatively limited displacement (several 

thousand feet). The anticline is itself thrust up over the eastern limb of the 

corresponding syncline; this limb extends to the southwest where it ends at another 

thrust fault near Green Spring. Outcrop-scale folds are parasitic on regional folds 

and appear to represent local adjustments during the same phase of folding. Two 

zones of tight minor folds are evident in the Elbrook Formation, one zone located at 

the village of White Hall, and the second along Braddock Road. A late-stage 

cross-strike fault (Orndorff, 1992) is seen along Hiatt Run on the west limb of the 

Welltown syncline, with smaller faults radiating around the nose of the fold further 

north.

 The North Mountain fault zone cuts through the eastern part of the 

quadrangle; it is a series of thrust faults generally oriented northeast–southwest that 

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

Cambrian and Ordovician carbonate rocks and shales (Fig. 1). The North Mountain 

fault zone widens north of Strasburg, Va. to north of Winchester, Va., and multiple 

splays of the primary thrust fault are evident in the White Hall quadrangle. The two 

faults bounding the fault zone are the Little North Mountain fault and the Apple Pie 

Ridge fault. The Little North Mountain fault lies on the west side of Little North 

Mountain and brings Silurian and Lower Devonian rocks onto Middle Devonian 

shales. The Apple Pie Ridge fault (Orndorff and others, 2003) thrusts the oldest 

rocks exposed in the quadrangle (Elbrook Formation) onto the Lower Ordovician 

Stonehenge Limestone and Conococheague Limestone. Dean and others (1994) 

named the thrust splay along the west side of Little North Mountain beginning at 

Green Spring the Back Creek fault; this is probably the northern extension of the 

Little North Mountain fault. The Back Creek fault has been traced approximately 24 

mi northward from Green Spring into Maryland and converges with the North 

Mountain fault zone at McCoy’s Ferry, Md.; thus, the ridge of Little North 

Mountain is a large horse (Dean and others 1994). Interruptions in the outcropping 

of the Tuscarora Quartzite along the Little North Mountain fault likely resulted from 

cross-strike faulting rather than from thinning of sedimentary strata (Giles, 1942); 

however, lack of outcrop precludes precise mapping of faults in these areas. A 

prominent north-south trending fault in the southeast part of the quadrangle area cuts 

along the east limb of the Welltown syncline, and is herein named the Welltown 

fault. It is manifested by pronounced thinning of the Stonehenge Limestone and by 

numerous calcite-filled tension gashes in limestone and shear structures within 

brecciated dolomite, observable in outcrops along the lineament. 

EXPLANATION OF MAP SYMBOLS

Bedrock contacts -- Dashed where approximately located; dotted where concealed

Alluvial contacts -- Identity and existence certain, location inferred

Faults -- Dashed where approximately located, dotted where concealed

Thrust fault -- teeth on hanging wall

 Strike-slip fault -- arrows indicate relative sense of movement

 Normal fault -- U, upthrown side; D, downthrown side

In cross sections, relative sense of movement is shown by arrows, and by: 

Strike and dip of beds

Inclined 

 Vertical 

 Overturned 

 Inclined; multiple observations at single point

 Overturned; multiple observations at single point

Strike and dip of joints--Point of observation at intersection of multiple symbols 

 Inclined; widely spaced (spacing >1m)

 Inclined; moderately spaced (spacing >0.3m and <1m)

 

 Inclined; closely spaced (spacing <0.3m)

 Vertical; moderately spaced

 

Strike and dip of cleavage

Inclined

Inclined; multiple observations at single point

 Vertical; multiple observations at single point

Strike and dip of tension gash

Vertical

 Inclined; multiple observations at single point

 Vertical; multiple observations at single point

Folds -- Showing trace of axial surface; large arrowhead indicates direction of plunge.

 Dashed where approximately located 

 Syncline

 Anticline

Overturned syncline

 Overturned anticline

Spring -- Tail indicates direction of flow

Sinkhole

Conodont fossil locality -- Showing collection number; sample information is linked to locality in the 

 digital geodatabase.

Photograph location -- Images are included in the digital geodatabase and linked to locality. A and B refer 

 to sites shown in Figure 2

I

F

P

M (

(

(

(

25

90

75

È

30

A

U

D

away from observer

toward observer

90

90

30

30

90

90

30

25

75

30

30

\

12104-CO

_e

O_c s

Os

Or

Op

On

Oc

Om

Ojo

St

Skr

Swbm

DSls

Dmn

Dm

Dmc

Dmch

Db

Df

Dfu

Dfl

Dh

b

t

Qa

DESCRIPTION OF MAP UNITS

Alluvium (Holocene and Pleistocene?)—Clay, silt, and lesser sand with angular to 

subrounded clasts, derived from local bedrock. Pebble-size (4–64 mm) fragments of 

sandstone, siltstone, quartzite and weathered shale are scattered throughout the deposits. 

In area underlain by the Martinsburg Formation, consists of light-olive-gray, yellowishgray, and pale-yellowish-orange, well-bedded to crudely bedded, planar-bedded clayey 

silt, with weathered shale fragments as much as an inch long. Thickness as much as 40 ft

Terrace deposits (Tertiary?)—Rounded to subrounded, highly weathered cobbles, sand, 

silt, and clay exposed along State Route 681 near the confluence of Isaacs Creek and Back 

Creek

Breccia (Permian?)—Brecciated massive dolomite or dolomitized limestone; may be 

silicified in places and contain black stringers or staining (Fe-Mn oxide?). Exposures 

occur in fields east of Frog Hollow and along the axis of the Welltown syncline

Hampshire Formation (Upper Devonian)—Sandstone, mudstone, siltstone, and minor 

shale. Sandstone, reddish-gray to brownish-gray, medium- to thick-bedded, in part micaceous and (or) arkosic, commonly crossbedded, unfossiliferous. Mudstone, maroon red, 

weathers into small lumps. Siltstone and shale, reddish-brown to gray, exhibits strong 

cleavage. Exposed thickness of unit as much as 850 ft. Upper part of formation not 

exposed in quadrangle. Lower contact placed at base of red-beds and at top of highest 

gray, fossiliferous sandstone and shale of the underlying Foreknobs Formation

Foreknobs Formation (Upper Devonian)—Interbedded sandstone, siltstone, and minor 

shale; locally fossiliferous. The main unit (Df) contains coherent packages of thickbedded to massive sandstone which occur as two ridge-forming units that are mappable 

throughout the study area. The upper ridge-forming unit (Dfu) consists of 5 to 6 masses of 

thick, resistant interbedded sandstone, siltstone, and shale 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 3 to 4 packages of thick-bedded to massive 

resistant interbedded sandstone, siltstone, and shale which form a prominent ridge at the 

base of the formation. The interval (Df) between the two ridge-forming units consists of 

thin- to medium-bedded sandstone, siltstone, and shale and typically occupies the drainage area between the two ridges; commonly not well exposed. The lower contact with the 

Brallier Formation is gradational through about 300 ft and is mapped where an abrupt 

increase in fossiliferous sandstone beds greater than 6 in. occurs. Thickness about 1,700 ft

Brallier Formation (Upper Devonian)—Interbedded shale, siltstone, and sandstone, 

dark-gray to greenish-gray, weathers light brownish-gray, sparsely fossiliferous. Grain 

size increases irregularly upward in section; sandstone beds, 2 to 6 in. thick, become more 

abundant near top of formation. Shale that is thickly laminated with scattered siltstone 

beds up to 3 in. thick makes up the bulk of the formation. The lower contact with the 

underlying Mahantango Formation is a disconformity above a massive sandstone unit 

(Dmc) at the top of the Mahantango. A mappable contact is placed at the top of this 

sandstone. Thickness approximately 1,100 ft 

Mahantango Formation (Middle Devonian)—Mudstone, shale, siltstone, and minor 

sandstone. Mudstone, dark-gray to olive-gray, hackly weathering, locally very fossiliferous; bedding obscure, spheroidal weathering common. Sandstone (Dmc, equivalent to 

Clearville Siltstone Member of Jolley, 1983), medium-gray, fine-grained, medium- to 

thick-bedded, generally massive, locally fossiliferous; occurs as two units near top of 

formation separated by mudstone; total thickness as much as 380 ft. Chaneysville 

Siltstone Member (Dmch) is predominantly massive darkgray siltstone and black 

mudstone occurring in the lower part of the formation, locally fossiliferous, up to 850 ft 

thick, grades into calcareous shale at base. Total thickness of entire formation ranges from 

1,600 to 1,800 ft. Lower contact gradational; placed at base of olive-gray beds above 

underlying Marcellus Shale

Marcellus Shale and Needmore Shale, undivided (Middle and Lower Devonian)— 

Black shale, silty shale, calcareous shale, and minor limestone. Thickness as much as 800 

ft; however, units are not well exposed in the quadrangle due to faulting and colluvial 

cover. Descriptions below are based upon mapping conducted in adjacent quadrangles

Marcellus Shale (Middle Devonian)—Shale, black to dark-gray, highly fissile, with 

localized beds or concretions of dark-gray, argillaceous limestone or calcareous shale. 

Forms thin, platy chips and weathers dusky yellowish-gray in exposed outcrops. Base of 

Marcellus is marked regionally by the Tioga Metabentonite; not seen in outcrops but may 

be present in covered intervals. Thickness up to 700 ft 

Needmore Shale (Middle and Lower Devonian)—Calcareous shale, dark-greenish-gray 

to olive-gray, and dark-gray fissile silty shale; locally fossiliferous. Thickness about 100 

ft. Grades upward into the Marcellus Shale through a series of thin limestone beds. Base 

placed at top of coarse sandstone of underlying Oriskany Sandstone. 

Oriskany Sandstone, Helderberg Group, and Tonoloway Limestone, undivided 

(Lower Devonian and Upper Silurian)—Sandstone, limestone, and shale. Thickness as 

much as 800 ft; however, units are not well exposed in the quadrangle due to faulting and 

colluvial cover. Descriptions below are based upon mapping conducted in adjacent quadrangles

Oriskany Sandstone (Lower Devonian)—Sandstone, light-gray, yellowish-gray-, or 

yellowish-brown-weathering, medium- to coarse-grained, medium- to thick-bedded, 

locally crossbedded, calcareous; locally conglomeratic with quartz pebbles up to 0.5 in. 

long; friable when weathered; contains molds of brachiopod shells. Base placed at top of 

cherty limestone of Licking Creek Limestone of Helderberg Group 

Helderberg Group, undivided (Lower Devonian and Upper Silurian)—Limestone, 

medium- to dark-gray, fine-grained, irregularly bedded, fossiliferous; contains black or 

light gray to white chert nodules, lenses, and beds as much as 1.5 ft thick near top; some 

limestone is medium gray, coarse grained, crinoidal. Individual units cannot be distinguished in the quadrangle due to faulting and colluvial cover. Lower contact placed at base 

of crinoidal limestone overlying shaly, laminated limestone of the Tonoloway Limestone 

based on mapping in other areas

Tonoloway Limestone (Upper Silurian)—Limestone and shale. Limestone, mediumgray to medium dark-gray, crinkly laminated to thin-bedded. Shale, medium-gray to 

dark-gray, calcareous. Locally contains ripple marks and mud cracks. Base placed at top 

of Tavenner Sandstone Member (Butts and Edmundson, 1966) of the Wills Creek Formation (not exposed in quadrangle)

Wills Creek Formation, Bloomsburg Formation, and McKenzie Formation, undivided (Upper and Lower Silurian)—Shale, sandstone, siltstone, and limestone. Thickness as much 275 ft

Wills Creek Formation (Upper Silurian)—Interbedded shale, siltstone, limestone, and 

sandstone. Shale, medium-dark-gray and greenish-gray to light-olive-gray, weathers 

yellowish-gray to reddish-gray, crinkly laminated, calcareous. Siltstone, greenish-gray to 

gray, weathers dark brownish-gray or grayish-yellow. Limestone, medium-dark-gray to 

olive-gray, very fine grained with local interclastic flat-pebble conglomerate. Sandstone 

primarily near top of unit, massive weathering, crossbedded, 15 to 20 ft thick, named 

Tavenner Sandstone Member by Butts and Edmundson (1966). Thickness of formation 

140 to 180 ft

Bloomsburg Formation (Upper Silurian)—Interbedded sandstone, siltstone, mudstone, 

and shale. Sandstone, reddish-brown to grayish-red, and gray, fine- to medium-grained, 

thin- to thick-bedded. Siltstone, grayish-red, reddish-brown, grayish-purple, mediumgray, light-olive-gray, and greenish-gray, thin- to medium-bedded, shows prominent 

cleavage. Mudstone maroon-red, weathers dusky pale red, forms cohesive lumps in 

outcrop. Shale, gray, greenish-gray, and reddish-brown. Lower contact is at base of red 

sandstone beds

McKenzie Formation (Upper and Lower Silurian)—Shale and siltstone. Shale, 

yellow-tan with silky luster, olive-gray and light-olive-gray, fissile, and fossiliferous. 

Siltstone, yellow-gray, calcareous

Keefer Sandstone and Rose Hill Formation, undivided (Lower Silurian)—Quartzite, 

sandstone, and shale. Thickness approximately 500 ft

Keefer Sandstone—Quartzite, medium-light-gray, coarse-grained to pebbly, massive, 

vitreous at base, grading up to medium-gray, medium-grained, and olive-gray, finegrained. Thickness about 130 ft

Rose Hill Formation—Sandstone and shale. Sandstone, reddish-brown, grayish-red, 

grayish-purple, and gray, medium- to coarse-grained, medium- to thick-bedded. Shale, 

gray, greenish-gray, and reddish-brown, locally silty, and hackly weathering, locally 

fossiliferous. Lower contact placed at base of red sandstone overlying massive quartzite 

ledges of Tuscarora Quartzite. Thickness about 370 ft

Tuscarora Quartzite (Lower Silurian)—Quartzite, light- to medium-gray, medium- to 

coarse-grained, thick-bedded, some beds conglomeratic. Base placed at bottom of quartzite ledges. Thickness about 250 ft

Juniata Formation and Oswego Sandstone, undivided (Upper Ordovician)-

Sandstone, shale, and conglomerate. Thickness about 250 ft

Juniata Formation—Sandstone and shale. Arkosic sandstone, grayish-red to brown, 

fine- to coarse-grained, thin- to medium-bedded, locally thick-bedded, crossbedded. 

Shale or mudrock, grayish-red; occurs as thin beds and partings, mostly near top of formation

Oswego Sandstone—Sandstone and conglomerate. Sandstone, greenish-gray, coarsegrained, thick-bedded, conglomeratic. Conglomerate, interbedded with sandstone, 

composed of rounded clasts of chert and sandstone. Sandstone friable where locally 

calcareous and fossiliferous

Martinsburg Formation (Upper and Middle Ordovician)—Interbedded shale and 

lesser graywacke-siltstone and graywacke-sandstone. Shale, medium-gray to dark-gray 

and light-olive-gray, weathers grayish-orange and dark yellowish orange, commonly silty, 

generally noncalcareous, although calcareous intervals occur in lower part of formation 

(Stickley Run Member). Siltstone and sandstone (immature, generally lithic graywacke), 

medium-gray, grayish orange weathering, very fine to fine-grained, commonly graded 

(fining upward), lenticular, slightly calcareous to noncalcareous; contains many small 

crossbeds. Graywacke is more abundant and more thickly bedded higher in section where 

it forms conspicuous ribs in creek beds and may constitute as much as 30 percent of some 

intervals that are several hundred feet thick. Thicker beds are generally graded and 

display characteristics of complete Bouma cycles. Regional thickness may be more than 

5,000 feet 

Chambersburg Formation (Middle Ordovician)—Interbedded limestone and calcareous shale. Limestone, medium-gray to medium-dark-gray, fine- to medium-grained, thinto thick-bedded, irregularly bedded, knobby weathering. Calcareous shale, mediumdark-gray to very dark-gray. Thickness as much as 500 ft

New Market Limestone (Middle Ordovician)—Limestone, medium-gray and dovegray, weathers very light-gray, thick-bedded, micritic, fenestral. Lower 10 ft is mediumgray to light-gray, thin-bedded dolomitic limestone interbedded with light-gray dololaminite. Base placed at top of uppermost medium-gray, thick-bedded dolostone of Pinesburg 

Station Dolomite (Op) and below dolomitic limestone of the New Market. Exposed thickness approximately 160 ft

Pinesburg Station Dolomite (Middle Ordovician)—Dolostone and dololaminite, 

medium- to light-gray, weathers buff-yellow to very light-grey, fine-grained, thick-bedded 

to massive, with minor white and light-gray chert nodules. Weathered surfaces exhibit 

"butcher-block" (cross-hatched joints) structure. Also contains a few thin, medium-gray, 

fine-grained limestone beds in lower part. Paleokarst features of irregular bedding and 

collapse breccia common near top of unit; breccia may be silicified, with localized iron 

mineralization. Lower contact placed at base of lowermost light-gray, thick-bedded dolostone overlying dominantly limestone cycles of the Rockdale Run Formation. Exposed 

thickness as much as 700 ft

Rockdale Run Formation (Middle and Lower Ordovician)—Interbedded limestone 

and dolostone. Limestone, bluish-gray, medium-gray, and dark-gray, fine- to mediumgrained, thin- to medium-bedded, fossiliferous. Dolostone, medium-gray, fine- to 

medium-grained, medium-bedded, crystalline. Lithologies occur as fining upward 

carbonate cycles capped by dololaminite beds as much as 2 ft thick. Limestone beds also 

contain intraformational conglomerates, algal bioherms, bioclastic zones, and burrow 

mottling. Gastropod Lecanospira is common in lower and middle parts of formation. 

Lower contact placed at base of lowermost crystalline dolostone or dololaminite bed 

overlying dark-gray, thick-bedded limestone of the Stonehenge Limestone. Exposed 

thickness approximately 1,200 ft; thickness uncertain due to faulting and folding

Stonehenge Limestone (Lower Ordovician)—Limestone, dark-gray, fine- to mediumgrained, thick-bedded to massive, fossiliferous, with crinkly laminations and minor black 

chert. Also contains algal bioherms, intraformational conglomerates, bioclastic beds, and 

minor dolostone beds. Gastropod Lecanospira is common in middle part of formation. 

Massive limestone may show mottles from dolomitic burrows. Contact with underlying 

Conococheague Limestone is gradational; base placed at first dark-gray limestone with 

crinkly siliceous laminations (Stoufferstown Member) and above the uppermost dolostone that caps Conococheague carbonate cycles. Thickness approximately 770 ft

Conococheague Limestone (Lower Ordovician and Upper Cambrian)—Interbedded 

limestone, dolostone, dololaminite and sandstone. Limestone, medium-gray, fine-grained, 

thin- to medium-bedded. Dolostone and dololaminite, light-gray, fine-grained, mediumbedded. Sandstone, light-gray to buff, orange-reddish weathering, medium- to coarsegrained, calcareous. Limestone lithologies include intraformational conglomerates, algal 

bioherms, ribbon rock, and oolites. Lithologies occur as carbonate cycles. Lower 295 ft, 

Big Spring Station Member, consists of gray to buff, orange-reddish weathering, coarsegrained calcareous sandstone; medium-gray, fine-grained limestone with intraformational 

conglomerate; and light-gray, fine-grained dolostone. Sandstone beds (s) also occur in 

middle part of formation and form ridges. Upper part of formation contains very lightgray weathering, medium-gray limestone with thin siliceous laminae. Base placed below 

lowermost calcareous sandstone bed of Big Spring Station Member. Thickness is approximately 2,800 ft

Elbrook Formation (Middle Cambrian)—Interbedded limestone, dolostone, and shale. 

Limestone, medium-gray, fine- to medium-grained, thin- to medium-bedded. Dolostone, 

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

yellowish weathering, dolomitic. Limestone contains algal bioherms, intraformational 

conglomerates, and dolomitic burrow mottles. Lowest beds exposed are bluish-gray, 

medium- to thick-bedded limestone with dolomite ribbons and mottles and medium-gray, 

thick-bedded dolostone of the middle part of formation. Cycles of bluish-gray algal 

limestone and grainstone and light-gray argillaceous dolostone occur in upper part of 

Elbrook. A distinctive lithology is yellowish weathering, thin-bedded dololaminite that 

appears shaly in weathered outcrops. Thickness is at least 2,500 ft; the thickness is 

increased by intraformational folding

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1000 feet = 305 meters

Surficial deposits not shown

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A

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12104-CO

12105-CO

12102-CO

12108-CO

12106-CO

12107-CO

\ \

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B'

B

A'

A

U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

HTRON CITENGAM

01 °

APPROXIMATE MEAN

DECLINATION, 2007 HTRON EURT

1000 0 1000 2000 3000 4000 5000 6000 7000 FEET

1 .5 0 1 KILOMETER

SCALE 1:24 000

1 1/2 0 1 MILE

Base from U.S. Geological Survey, 1965

Polyconic projection. 1927 North American datum

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

1,000-meter Universal Transverse Mercator grid ticks, zone 17, shown in blue

To place on the predicted North American datum 1983

move the projection lines 7 meters south and 23 meters west 

as shown by dashed corner ticks CONTOUR INTERVAL 20 FEET

Geology mapped by R.A. Parker 1992–1993, 

and by D.H. Doctor, R.C. Orndorff, D.J. Weary,

and J.E. Repetski 2006–2009

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

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

VIRGINIA

MAP LOCATION

W.VA.

UNIT CONVERSION FACTORS

1 inch (in.) = 25.4 millimeter (mm)

1 foot (ft) = 0.3048 meter (m)

1 mile (mi) = 1.609 kilometer (km)

1 cubic foot per second (cfs) = 0.02832 cubic meter per second (m /sec) 3

OPEN-FILE REPORT 

 OF 2010-1265