1500

1500

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1900

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1450

1400

1400

1450

1400

1200

1250

1300

1300

1300

1300

1350

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1150

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1700

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1700

1700

1750

1750

1150

1200

1200

1250

1250

1200

1400

1400

1350

1550

1550

1550

1550

1950

1950

2000

1550

1550

1560

1580

1920

1960

1930

1950

1910

1510

1850

1520

1520

1490

1430

1430

1440

1190

1170

1160

1440

1400

1440

1445

1465

1460

1425

1420

1850

1780

1760

1805

1790

1870

1880

1840 1860

1175

1270

1335

1340

1350

1390

1390

1380

1370

1365

1360

1345

1410

1400

1470

1470

1440

1435

1360

1340

1340

1365

1370 1360

1350

1340

1280

1220

1220

1845

1865

1825

1850

1850

1840

1840

1840

1840

1840

1350 1130

1150

1150

1160

1165

1130

1745

1790

1770

1180

1770

1760

1750

1660

1630

1610

1685

1680

1545

1560

1710

1740

1730

1730

1760

1740

1740

1760

1740

1725

1710

1720

1720

1630

1660

1570

1600

1780

1760

1770

1480

1130

1145

1140

1790

1750

1735 1210

1750

1770

1145

1320

1120

1780

1800

1190

1130

1150

1130

1330

1330

1300

1305

1250

1350

1340

1340

1320

1920

1320

1890

1380

1400

1895

1835

1930

1900

1785

1820

1800

1790

1730

1790

1720

1720

1790

1780

1750

1770

1760

1780

1780

1780

1820

1800

1820

1810

1815

1860 1860

1815

1720

1770

1750

1775

1795 1765

1770

1800

1745

1750

1750

1720

1730

1740

1760

1790

1790

1760

1720

1780

1760

1740

1345

1850

1350

1330

1350

1880

1890

1890

1850

1880

1900

1485

2015

1920

1900

1800 1790

1980

1980

1520

1520

1520

1540 1540 1540

1610

1600

1545

7

2

4

3

1

1

4

1

4

1

2

4

2

3

9

4

6

6

3 2

2

2

3 5

4

1

3

3

5 3

7

2

6

6

2

2

6

3

3

2 2

9

3

2

6

8 5

8

5 13

12 6 3

4

4

6 2

6

6 6

4

9

3

5

3

3 3

5

4 5

12

10

2

3 10

7

4

2

4

4

3

3 8

5

5

1 2

5

7

8

8 6

2

3

3

3

3 6 2

2

2 3

4

2

2

2

2

6

3

7

3

4

3

4

6

2

3

8

8 9

4

2

4 3 3

6

6

5

4

7 7

5

6 7

2

12

11 5

12

15

15

2

2

3

4

4

4

2

2

2

2

2

2

2

11

13

45

10

8

7

7

7

10

2 3

5

3

2

1

2

2

5

4

3

4

2

4

15

11

7

7

5

7

3

1 1

2

4

7

10

6

3

8 3

3

8

7

6

4

4

4

5 3

2

5

3

4

4 3 3

4

5

5

2

2

6

4

3

4

5

5

4

3

3

2

2

2

3

4

3

3 3

3

1

5

3

3 4

26

9

3 4 3

2

4

5

3

6

6

2

3

4

7 3

3 3

3

1

1

11

2

1 7

9

3

3

13

4

1

3

1 6

2

3

2

2

3

8

8

2

4

4

5

5 2

6

7

5

3 14

3

9

8

2

20 13 3

18

17 15

4

4

3

4

2

2 5

4

4

3

3

5

5

2

5

4 1

9

4

4

3

3

2

5

2

2

1

2

2

2

3

2

2 2

3

3

4

4

2

5 6 6

3

8 1

2

6

7

2

2

3

1

5

5 5

8

2

3

3

5

5 4

2

5

6

2

2

2

4 4

4

4

3

2 1

11

8

7

3

4

4

5

3

7

4

3

7

9 5 3

6

3

2

2

1 5

2

1 2

5

2

5

6

3

3

5

4

5 2

3

3

4

4

5

4

5

11 8 8

12

19

19 12

21

18 16

8

4 8

3

3

3

3 4

4

10

4

4

7

10

4

7

7

5

5

3

4

8 8

3

2

2

2

2

2

2

3

3

4

4

7

4 1

5

5

3

3

3

4

4

4

2

3

4

4

4

6

5

3

3

3

3 5

3 2

1

2

7

4

3

2

8

4 2

2

3

1

1 3

3

6

6

8

4

2

3

4

4

4

8

15

2

2

2

2

2

2

1

2

3

8

6

3

2

4

4

2

7

7

5

5

5

5 6

16

3

2

7

9

5

3

2

5

27 14

17

2

13

2

12

12

48

28

11

11 8

5 5

5

5

4 3

2

1

14

6

4

2

2

4

4

5 5

3

2

4

7

12

7

6

4

4

3 2

2

6

6

6

4

6

3

7

1 3

3

3

4 4

4

4

7

5

3

3

7 2

2

5

2

2

5

5 4

4

4

1 3

3

2

5

5 4

2

4 3

7

3

3

10

5

2 2

B'

0

2,500

2,000

1,500

1,000

500

FEET

SOUTHEAST

B

0

2,500

2,000

1,500

1,000

500

FEET

NORTHWEST

VERTICAL EXAGGERATION X2

HENSON CREEK FAULT

Henson Creek

bu

bu

bl hg hg bl

Mf

Mf

Mp

Mb

Oe

Oe

Ou

Ou

Mbs

Mbs

Mb

Mbv

Mbv

hc

hc

hg bu

a

0

2,500

2,000

1,500

1,000

500

FEET

NORTHWEST

A

VERTICAL EXAGGERATION X2

0

2,500

2,000

1,500

1,000

500

FEET

SOUTHEAST

A'

Oe

Oe

Mf

Mp Mp

Mbv

Oe Mbs Mb

Mf

bl hc

hc hc

Mbv

Mb

Mbs Mbv

Mbs

Ou Ou

Of

Mf

Mb Mbv

Mbs

Ou

Qty

Mp

Little Buffalo River

KEYS GAP MONOCLINE

Dog Branch

TAYLOR MOUNTAINFAULT

SYNCLINE

Qty Qty

bl bu bu

bl

a

a

Running Creek

TAYLOR MOUNTAIN

Haunt Hollow

E

n = 90

N N

W E W E

S S

n = 22 n = 16

Normal faults Strike-slip faults

S S

N N

W E W

n = 1,224

N

W E

S

EXPLANATION

Multiples of standard

deviation

A

B

C

Figure 5. Structural data from the Murray quadrangle. Number of 

data are “n”. A, Rose diagram of strike frequency (left ) and 

stereoplot of poles and orientation density contours (right) for 

faults in quadrangle. Contour levels are multiples of standard 

deviations. B, Subset of striated faults with known slip sense that 

are compatible with normal (left) and strike-slip (right) 

paleostress regimes. Arcs are lower hemisphere projections of 

fault planes and solid and open dots are slip lines with components 

of normal and reverse slip, respectively. Small arrows show 

movement sense of hanging wall block. Red large, medium, and 

small filled circles represent orientation of maximum, 

intermediate, and least principal paleostress axes, respectively, 

from analysis of Angelier (1990). Large black arrows show 

azimuth of least horizontal compression. C, Rose diagram of 

strike frequency of joints recorded within the map area.

1–2

2–4

4–6

>6

1800

1900

1850

1850

1800

1850

1900

1950

1900

2000

1800

1750

1750

1750

1800

1750

1800

1800

1700

1800

1750

1700

1800

1800

1900 1850

1700

1650

1600

1750

1700

1400

1400

1400

1500

1600

1550

1350

1550

1450

1350

1300

1250

1150

1200

1200

1300

1150

1250

Monocline

Line of section

Syncline

Base of middle Bloyd sandstone (Pbu).

 Hachures point to closed areas of 

 lower values

Top of Boone Formation (Mb). Hachures

 point to closed areas of lower values

EXPLANATION

1800

1400

Normal, right-lateral, strike-slip fault—

 Ball and bar on downthrown block,

 arrows show relative motion

Fault site—offset sense

Unknown

Normal

Oblique normal

strike-slip

reverse

Structure contour elevation, in feet

Mine

Anticline

A A’

0 1 MILE

0 1 KILOMETER

36o

93o 22' 30" B

A’

A

B’

KEYS GAP MONOCLINE

KEYS 

 GAP

MONOCLINE

35o 52' 30"

93o 15'

Bean

Mountain

HOGHEAD CREEK

TAYLOR MOUNTAIN FAULT

HENSON

FAULT

CREEK

FAULT

Digital Elevation Model base from the U.S. Geological Survey, Earth Resources Observation and Science (EROS) Center, 2003

North American Datum of 1927 (NAD 27), Universal Transverse Mercator (UTM), zone 15N

Figure 4. Shaded-relief digital elevation map of quadrangle with locations of structural features and sites where faults were 

observed. Slip senses for faults at sites are indicated as normal (rake 90o to 60o), oblique (rake 59o to 30o), strike-slip (rake 

29o to 0o) or reverse (rake >30°). Also shown are approximate locations of former lead-zinc mine sites of Little Buffalo River 

district, as described by McKnight (1935).

B

Fault

Fault

Figure 3. A, Photograph of an exposure along Stepp Creek in the southern part of the 

quadrangle of crinoid-bearing limestone clasts of probable Mississippian Pitkin 

Formation origin that are included in the basal conglomerate of overlying Pennsylvanian 

Cane Hill Member of Hale Formation (hc). Global positioning satellite receiver is 4 in 

long for scale. B, Conjugate normal faults with small offset (<4 in) cutting middle Bloyd 

sandstone ledges (base of Pbu). Photographs by M.R. Hudson, 2013.

A

200

100

400

500

500

700

600

800

900

1,000

1,100

1,200

1,400

1,500

1,300

1,600

500

400

300

200

100

0 0 

METERS FEET

Boone Formation

Fayetteville Shale

Batesville Sandstone

St. Joe Limestone Member

Cane Hill Member

Prairie Grove Member

upper part

Hindsville Limestone Member

Bloyd Formation

Atoka

Formation

HaleFormation

lower part

Fernvale Limestone

MeramecianOsagean Osagean- Kinderhookian Provincial Series

ORDOVICIAN MISSISSIPPIAN PENNSYLVANIAN (part) SYSTEM

Pitkin Limestone

middle Bloyd sandstone

Everton Formation

Morrowan Atokan Chesterian

Cross-bedded sandstone

Sandstone

Calcareous sandstone

Shale, siltstone

Limestone

Dolomite

Chert

EXPLANATION

Major unconformity

Minor unconformity

Figure 2. Stratigraphic column for Paleozoic rocks representative of the map area. Provincial series are from 

Purdue and Miser (1916) and McFarland (1988).

OZARK DOME

94° 92° 90° 

MISSISSIPPI EMBAYMENT

ARKANSAS

ARKOMA BASIN

Ouachita Mountains

Boston Mountains

MISSOURI

TENN

MISS

OKLA

KAN

St. Francois

SALEM 

PLATEAU

Springfield

Plateau

Mountains

37°

35°

33°

TEXAS

Harrison

43

7

65 

River

Buffalo

SNOWBALL

OSAGE NE

OSAGE SW

GAITHER HARRISON

JASPER WESTERN

GROVE

MT.

JUDEA

EULA BOXLEY MURRAY

HASTY

PARTHENON

PONCA ST. JOE MAUMEE

MARSHAL

SIM 2991

(Hudson and

Turner, 2007)

SIM 3360

(Hudson and

Turner, 2016)

MF 2412

(Hudson and

Murray, 2003)

MF 2356

(Hudson and

others, 2001)

OFR 98–116

(Hudson, 1998)

SIM 2847

(Hudson and

Murray, 2004)

SIM 2921

(Hudson and

others, 2006)

SIM 3314

(Hudson and

Turner, 2014)

SIM 3074

(Hudson and

Turner, 2009)

SIM 3134

(Turner and

Hudson, 2010)

36°

36°15'

35°52’30”

36°07’30”

93°22'30” 93°15' 93°07'30”

93°30' 92°45' 92°37'30”

93°

92°52’30”

BUFFALO

NATIONAL

RIVER

0

0

5 MILES

5 KILOMETERS

Figure 1. Location of study area in northern Arkansas, adjacent to the western part of Buffalo National River are 

highlighted in yellow and their publication numbers are shown. Lower regional map shows geologic and selected 

physiographic provinces of Arkansas and adjacent areas. The Ozark Plateaus region includes Salem and Springfield 

Plateaus and Boston Mountains physiographic provinces. U.S. Geological Survey Scientific Investigations Map 3314 

in dashed green outline. This report in dashed red outline.

SCALE 1: 24 000

1 1/ 2 0 1 MILE

1000 1000 0 2000 3000 4000 5000 6000 7000 FEET

1 0 .5 1 KILOMETER

ARKANSAS

MAP LOCATION

Base from U.S. Geological Survey 1:24,000-scale Murray, Arkansas, 1968

Polyconic projection, North American Datum 1927 (NAD 27)

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

1,000-meter Universal Transverse Mercator grid ticks, zone 15

APPROXIMATE MEAN

DECLINATION, 2016 TRUE NORTH MAGNETIC NORTH

1°

CONTOUR INTERVAL IS 20 FEET

DATUM IS MEAN SEA LEVEL

Geologic mapping by M.R. Hudson and K.J. Turner 2010–2015

Digital database by K.J. Turner

Geologic Map of the Murray Quadrangle, Newton County, Arkansas

By

Mark R. Hudson and Kenzie J. Turner

2016

For more information concerning this publication, contact:

Center Director, USGS Geology and Environmental Change Science Center

Box 25046, Mail Stop 980

(303) 236-5344

Or visit the Geology and Environmental Change Science Center Web site at:

http://esp.cr.usgs.gov/

Digital files available at http://dx.doi.org/10.3133/sim3360

 

Publishing support provided by: 

Denver Publishing Service Center

Edit and digital layout by L.J. Binder

Manuscript approved for publication June 15, 2016

To learn about the USGS and its information products visit

http://www.usgs.gov/ 

1-888-ASK-USGS

Suggested citation: Hudson, M.R., and Turner, K.J., 2016, Geologic map of the Murray 

quadrangle, Newton County, Arkansas: U.S. Geological Survey Scientific Investigations

Map 3360, scale 1:24,000, http://dx.doi.org/10.3133/sim3360.

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3360

This map or plate is offered as an online-only, digital publication. Users should be 

aware that, because of differences in rendering processes and pixel resolution, 

some slight distortion of scale may occur when viewing it on a computer screen or 

when printing it on an electronic plotter, even when it is viewed or printed at its 

intended publication scale.

Conversion Factors

Multiply By To obtain

Length

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

Altitude, as used in this report, refers to distance above sea level.

BUFFALO

NATIONAL RIVER

B

B'

A

A'

TAYLOR

MOUNTAIN

FAULT

HOGHEAD

CREEK

FAULT

HENSON

CREEK

FAULT

KEYS

GAP

MONOCLINE

KEYS

GAP

MONOCLINE

Location of

photograph

in fig. 3A

Location of

photograph

in fig. 3B

Qty

hc

hc

Qc

hg

hg

hg

hg

bl

bl

bl

hg

hg

Mbv

Mb

Mp

hg

hc

bl

hc

hg

a

hg

a

a

a

a

a

a

a

a

a

a

a

a

a

a

hc

hc

hc

hc

hc

hc

hg

hg

hc

Mp

Mp

Mp

Mp

Mp

bl

bl

bl

bl

bl

bu

bu

bu

bu

hg

hg

bl

bl

bl

bu

bu

Qc

Qc

Qc

Qc

Qc

Qls

bu

bu

a

a

a

hc

hc

hg hc

hc

hc

hc

hc

hc

hc

bl

bl

bl

bl

bl

bl

hg

hg

bl

bl

bu

bl

bu

bu

bu

bu

bu

bu

bu

bu

Mbs

Mp

Mbs Mf

Qc

Mf

Mf

Mf

Mf

Mf

Mf

Mp

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mf Mb Mb

Mb

Qal

Qc

Qc

Mbv

Mbv

Qc

Mbv

Mbv

Mbv

Mbv

Qto

Qty

Qty

Qty

Qto

Qc

Qc

Qls

Qls

Qc

Mbs

Mp

Mp

Mf

Mf

Mf

Mf

Mf

Qls

Qal

Mf Mp

Mf

Mf

Mf

Mf

Mf

Mb

Mbv

Mbv

Mp

Mp

Mp

Mp

Mp

Mp

Mp

Mb

Mb

Mp

Mbv

Mp

Mp

Oe

Of

Oe

REFERENCES CITED

Angelier, Jacques, 1990, Inversion of field data in fault tectonics to obtain the regional stress—III, 

A new rapid direct inversion method by analytical means: Geophysical Journal International, 

v. 103, p. 363–376.

Arkansas Geological Survey, 2016, Fayetteville gas play: Arkansas Geological Survey, accessed 

June 1, 2016 at http://www.geology.ar.gov/fossilfuel_maps/fayetteville_play.htm.

Craig, W.W., 1975, Stratigraphy and conodont faunas of the Cason Shale and Kimmswick and 

Fernvale Limestones of northern Arkansas, in Wise, O.A., and Hendricks, K.N., eds., 

Contributions to the Geology of Arkansas Ozarks, v. 2: Arkansas Geological Commission,

p. 61–95.

Glick, E.E., and Frezon, S.E., 1953, Lithologic character of the St. Peter Sandstone and Everton 

Formation in the Buffalo River Valley, Newton County, Arkansas: U.S. Geological Survey 

Circular 249, 39 p. [Also available at https://pubs.er.usgs.gov/publication/cir249.]

Gordon, Mackenzie, Jr., 1964, Carboniferous cephalopods of Arkansas: U.S. Geological Survey 

Professional Paper 460, 322 p. [Also available at https://pubs.er.usgs.gov/publication/pp460.]

Handford, C.R., 1986, Facies and bedding sequences in shelf-storm-deposited carbonates—Fayetteville

Shale and Pitkin Limestone (Mississippian), Arkansas: Journal of Sedimentary Petrology, v. 

56, 123–137.

Henbest, L.G., 1953, Morrow Group and lower Atoka Formation of Arkansas: American 

Association of Petroleum Geologists Bulletin, v. 37, p. 1935–1953.

Horner, G.J., and Craig, W.W., 1984, The Sylamore Sandstone of north-central Arkansas, with 

emphasis on the origin of its phosphate, in McFarland, J.D., III, ed., Contributions to the 

geology of Arkansas, v. 2: Arkansas Geological Commission, p. 51–85.

Hudson, M.R., 1998, Geologic map of parts of the Jasper, Hasty, Ponca, Gaither, and Harrison 

quadrangles in and adjacent to Buffalo National River, northwestern Arkansas: U.S. 

Geological Survey Open-File Report 98–116, scale 1:24,000. [Also available at 

https://pubs.er.usgs.gov/publication/ofr98116.]

Hudson, M.R., 2000, Coordinated strike-slip and normal faulting in the southern Ozark dome of 

northern Arkansas—Deformation in a late Paleozoic foreland: Geology, v. 28, p. 511–514. 

[Also available at http://geology.gsapubs.org/content/28/6/511.short.] 

Hudson, M.R., and Murray, K.E., 2003, Geologic map of the Ponca quadrangle, Newton, Boone, 

and Carroll Counties, Arkansas: U.S. Geological Survey Miscellaneous Field Studies Map 

MF–2412, scale 1:24,000. [Also available at http://pubs.usgs.gov/mf/2003/mf-2412.]

Hudson, M.R., and Murray, K.E., 2004, Geologic map of the Hasty quadrangle, Boone and Newton 

Counties, Arkansas: U.S. Geological Survey Scientific Investigations Map 2847, scale 

1:24,000, [Also available at http://pubs.usgs.gov/sim/2004/2847/.]

Hudson, M.R., Murray, K.E., and Pezzutti, Deborah, 2001, Geologic map of the Jasper quadrangle, 

Newton and Boone Counties, Arkansas: U.S. Geological Survey Miscellaneous Field Studies 

Map MF–2356, scale 1:24,000. [Also available at http://pubs.usgs.gov/mf/2001/mf-2356.]

Hudson, M.R., and Turner, K.J., 2007, Geologic map of the Boxley quadrangle, Newton and 

Madison Counties, Arkansas: U.S. Geological Survey Scientific Investigations Map 2991, 

scale 1:24,000. [Also available at http://pubs.usgs.gov/sim/2991/.]

Hudson, M.R., and Turner, K.J., 2009, Geologic map of the St. Joe quadrangle, Searcy and Marion 

Counties, Arkansas: U.S. Geological Survey Scientific Investigations Map 3074, scale 

1:24,000. [Also available at http://pubs.usgs.gov/sim/3074/.]

Hudson, M.R., and Turner, K.J., 2014a, Geologic map of the west-central Buffalo National River 

region, Arkansas: U.S. Geological Survey Scientific Investigations Map 3314, 1:24,000 scale, 

http:// dx.doi.org/10.3133/sim3314.

Hudson, M.R., and Turner, K.J., 2014b, Thickness variations of Upper Mississippian strata in the 

western Buffalo River region of northern Arkansas—Evidence of Late Mississippian tectonic 

activity in the southern Ozark Dome in South-Central Section, Geological Society of America 

48th Annual Meeting, March 17–18, 2014, Fayetteville, Ark.: Geological Society of America 

Abstracts with Programs, v. 46, no. 1, p. 3.

Hudson, M.R., Turner, K.J., and Repetski, J.E., 2006, Geologic map of the Western Grove 

quadrangle, northwestern Arkansas: U.S. Geological Survey Scientific Investigations Map 

2921, scale 1:24,000, [Also available at http://pubs.usgs.gov/sim/2006/2921/.]

Manger, W.L., and Sutherland, P.K., 1992, Analysis of sections presumed to be complete across the 

Mississippian-Pennsylvanian boundary, southern mid-continent, in Sutherland, P.K., and 

Manger, W.L., eds., Recent advances in middle Carboniferous biostratigraphy—A symposium: 

Oklahoma Geological Survey Circular 94, p. 69–79.

Marshak, Stephen, and Paulsen, Timothy, 1996, Midcontinent U.S. fault and fold zones—A legacy 

of Proterozoic intracratonic extensional tectonism: Geology, v. 24, p. 151–154.

McFarland, J.D., III, 1988, The Paleozoic rocks of the Ponca region, Buffalo National River, 

Arkansas, in Hayward, O.T., ed., South-Central Section of the Geological Society of America 

(Centennial Field Trip Guide), v. 4: Geological Society of America, p. 207–210.

McKnight, E.T., 1935, Zinc and lead deposits of northern Arkansas: U.S. Geological Survey 

Bulletin 853, 311 p. [Also available at https://pubs.er.usgs.gov/publication/b853.]

Purdue, A.H., and Miser, H.D., 1916, Eureka Springs-Harrison folio, Arkansas-Missouri: U.S. 

Geological Survey Folios of the Geologic Atlas GF–202, scale 1:125,000. [Also available at 

https://pubs.er.usgs.gov/publication/gf202.]

Smith, D.K. and Hutto, R.S., 2007, Geologic map of the Witts Springs Quadrangle, Searcy County, 

Arkansas: Arkansas Geological Survey Digital Geologic Quadrangle Map DGM–AR–00927, 

scale 1:24000. [Also available at http://www.geology.ar.gov/geologic_maps/dgm24k.htm.]

Suhm, R.A., 1974, Stratigraphy of Everton Formation (early Medial Ordovician), northern 

Arkansas: American Association of Petroleum Geologists Bulletin, v. 58, p. 685–707.

Sutherland, P.K., 1988, Late Mississippian and Pennsylvanian depositional history in the Arkoma 

basin area, Oklahoma and Arkansas: Geological Society of America Bulletin, v. 100, p. 

1787–1802.

Turner, K.J., and Hudson, M.R., 2010, Geologic map of the Maumee quadrangle, Searcy and 

Marion Counties, Arkansas: U.S. Geological Survey Scientific Investigations Map 3134, scale 

1:24,000. [Also available at http://pubs.usgs.gov/sim/3134/.]

U.S. Geological Survey, 2003, 10-meter Digital Elevation Models (DEMs) and orthophotographs: 

U.S. Geological Survey, Earth Resources Observation and Science (EROS) Center. [Now 

available at The National Map, http://nationalmap.gov/index.html.]

Zachry, D.L., 1977, Stratigraphy of middle and upper Bloyd strata (Pennsylvanian, Morrowan), 

northwestern Arkansas, in Sutherland, P.K., and Manger, W.L., eds., Upper 

Chesterian-Morrowan stratigraphy and the Mississippian-Pennsylvanian boundary in 

northeastern Oklahoma and northwestern Arkansas, Guidebook for field trip no. 5, August 

5–7, 1977: Oklahoma Geological Survey Guidebook 18, p. 61–66.

Zachry, D.L., and Sutherland, P.K., 1984, Stratigraphy and depositional framework of the Atoka 

Formation (Pennsylvanian), Arkoma basin of Arkansas and Oklahoma, in Sutherland, P.K., 

and Manger, W.L., eds., The Atokan series (Pennsylvanian) and its boundaries—A 

symposium, South-Central Section of the Geological Society of America, Proceedings, March 

29, 1982, Norman, Okla.: Oklahoma Geological Survey Bulletin 136, p. 9.

ACKNOWLEDGMENTS

This work was carried out as a cooperative project between the U.S. Geological Survey and 

the National Park Service.

STRATIGRAPHY

 The study area preserves an approximately 1,600-ft-thick record of early and late 

Paleozoic deposition on what is now the southern margin of the North American continent. 

Provincial series for Pennsylvanian and Mississippian units are from McFarland (1988).

The Middle Ordovician Everton Formation (Oe) is a heterogeneous sandstone and carbonate 

unit that Suhm (1974) interpreted to have been deposited in barrier island and tidal flat depositional 

environments. The Everton Formation is unconformably overlain by the Upper Ordovician 

Fernvale Limestone (Of) that was deposited as a shallow-water carbonate shelf sand (Craig, 1975). 

The Mississippian Boone Formation (Mb) is widespread within the northern part of the 

quadrangle. The phosphate-nodule-bearing sandstone at the base of the St. Joe Limestone Member 

(Mbs) of the Boone Formation is persistent throughout much of northern Arkansas (McKnight, 

1935) and was probably deposited in the Early Mississippian as a transgressive lag during sea-level 

rise (Horner and Craig, 1984). The contact of the main body of the Boone Formation with the St. 

Joe Limestone Member is gradational and is based on the change to the thin bedding and the 

generally chert-free lithology of the St. Joe Limestone Member. Near the top of the Boone 

Formation an oolite interval as thick as 3 ft is present. 

Locally, the Hindsville Limestone Member of the Batesville Sandstone contains angular chert 

fragments that were probably derived from the underlying Boone Formation and demonstrates a 

depositional hiatus between the Boone Formation and Batesville Sandstone (Mbv). Continued 

Chesterian transgression allowed accumulation of the black, organic-rich Fayetteville Shale (Mf) in 

a deep shelf setting followed by regression and deposition of the upward coarsening Pitkin 

Limestone (Mp) (Handford, 1986).

The onset of Morrowan deposition reflects a sea-level rise following a terminal Mississippian 

sea-level drop (Sutherland, 1988; Manger and Sutherland, 1992). Consequently, the base of the 

Morrowan Cane Hill Member (hc) of the Hale Formation represents a significant unconformity 

within the map area. The thinning and local absence of the Pitkin Limestone beneath this unconformity in the northern part of the quadrangle is likely due to Late Mississippian-Early Pennsylvanian 

erosion. This conclusion is supported by the common presence of probable limestone clasts 

(probably of the Pitkin Limestone) within basal conglomerate lenses of the Cane Hill Member of 

the Hale Formation. A 20-ft-thick mixed interval of limey sandstone, crinoidal limestone, and black 

shale at top of the Pitkin Limestone is well exposed along Stepp Creek (35.878°N., 93.312°W.) in 

the southern part of quadrangle and is preserved below a basal Cane Hill Member conglomerate 

bed with large limestone clasts (fig. 3A). This sandy limestone interval may be correlative with 

latest Mississippian lower Imo Formation (Gordon, 1964), which has been mapped to the south and 

east of the map area (Smith and Hutto, 2007; Angela Chandler and Richard Hutto, Arkansas 

Geological Survey, personal commun., 2014). The basal sandstone channels of the Cane Hill 

Member grade laterally and upward into thin bedded, rippled, fine- to very fine grained sandstones 

and siltstones that were probably deposited in tidal flat environments (Manger and Sutherland, 

1992). The study area is within the distribution of thick sand-rich facies of the Prairie Grove 

Member (hg) of the Hale Formation (Sutherland, 1988). 

Limestone of the Brentwood Limestone Member of the Bloyd Formation is not mapped 

separately and is included in the lower part (bl) of the Bloyd. It is conformable with the underlying Prairie Grove Member (hg) such that the contact is commonly gradational. The presence of 

limestone conglomerates with clasts of sandstone and siltstone as well as fossil fragments indicates 

a high-energy marine environment during deposition of part of the lower part of the Bloyd 

Formation. Pennsylvanian sandstone and shale of the upper part of the Bloyd Formation (bu) 

were originally called Winslow Formation by Purdue and Miser (1916), with the basal Greenland 

Sandstone Member of the Atoka Formation (Henbest, 1953) representing the prominent cliff-forming cross-bedded sandstone. Zachry (1977), however, concluded that the cliff-forming sandstone 

was a time-equivalent unit with the Woolsey Member of the Bloyd Formation farther west and 

designated it with the informal term “middle Bloyd sandstone” that was deposited in a braided river 

environment. The middle Bloyd sandstone interval comprises the basal interval of the upper part of 

the Bloyd Formation map unit as used here. Upsection from the middle Bloyd sandstone interval, 

siltstone and shale intervals are mixed with fine to coarse sandstones with some containing quartz 

pebbles similar to the middle Bloyd interval and some extensively bioturbated indicating a marine 

transgression above the river deposits. The interval of calcite cemented sandstone or bioclastic 

limestone in the upper part of the section indicates a brief incursion of a shallow marine environment. 

The Atoka Formation (a) is a sequence of alternating marine sandstone and shale that has 

generally been interpreted to represent fluvio-deltaic depositional environments in the southern 

Ozarks region (Zachry and Sutherland, 1984). The basal contact is well defined 38 miles (mi) to the 

west in Washington County where the Kessler Limestone Member at the top of the Bloyd Formation is unconformably overlain by shale of the Trace Creek Member of the Atoka Formation 

(Zachry and Sutherland, 1984). There, sandstone intervals of the Atoka Formation are principally 

fine- to very fine-grained and laterally extensive. The contact between the Bloyd and Atoka 

Formations in the Buffalo River area has been more difficult to define due to the absence of a 

distinctive underlying limestone. Within the Ponca 7.5-minute quadrangle, Hudson and Murray 

(2003) placed this contact above the level of a thin coal bed approximately 250 ft above the base of 

the middle Bloyd sandstone. In the Boxley 7.5-minute quadrangle, the Bloyd-Atoka contact was 

placed at a similar level above the middle Bloyd sandstone within a shale interval beneath an 

approximately 100-ft-thick interval of laterally extensive ripple laminated fine- to very fine-grained,

thin to medium bedded sandstone that underlies a prominent topographic ledge (Hudson and 

Turner, 2007). We have continued with this convention in the Murray quadrangle, but also note the 

presence of a sandy limestone interval observed at two locations (35.888°N., 93.300°W. and 

35.911°N., 93.290°W.) in the southern part of the quadrangle that are 140–180 ft above the middle 

Bloyd sandstone. The Kessler Limestone Member in Washington County is an oolitic limestone 

bearing algal nodules (Henbest, 1953) whose lithology is different from the sandy bioclastic 

limestone interval that we observed in this quadrangle; thus we do not think they are correlative. 

STRUCTURAL GEOLOGY

Structure contours on the top of the Mississippian Boone Formation and the bottom of the 

prominent middle Bloyd sandstone of the upper part of the Pennsylvanian Bloyd Formation 

illustrate how faults and folds in two main structural zones deformed rocks within the map area. 

Structure contours conform to elevations at 99 and 138 control sites on the Boone Formation and 

Bloyd Formation reference contacts, respectively; other limiting information was used for their 

minimum elevations above hilltops or their maximum elevations below valley bottoms. Structure 

contours for the Boone Formation are not extended into the southeastern parts of the quadrangle 

where no control sites were available.

The dominant structural feature of the quadrangle is a N.32°E.-trending fault and fold zone 

that transects the quadrangle and drops strata to the southeast (fig. 4). The northeastern part of this 

structural zone is formed by the N.40°E.-trending Henson Creek fault and adjacent dipping strata. 

Along cross section B–B', throw of the Boone Formation-Batesville Sandstone contact across 

Henson Creek fault is about 100 ft with lowering of an additional 150 ft by folding that mostly 

affects the downthrown southeastern block of the fault. The Henson Creek fault is interpreted to 

continue northward to merge with the southern end of the N.55°E.-trending Carlton fault (Hudson 

and Turner, 2014a), although poor bedrock exposure in the Panther Creek drainage within the 

Jasper 7.5-minute quadrangle obscures this connection. To the south, the Henson Creek fault 

terminates into the Keys Gap monocline that continues southwestward, aligning with parts of the 

Little Buffalo River valley in the center of the quadrangle and continuing along Thomas Creek in 

the south. It is likely that faults like the Henson Creek fault lie at depth beneath the Keys Gap 

monocline (cross section A–A'). Structure contours demonstrate that both the top of the Boone 

Formation and the base of the middle Bloyd sandstone drop to the southeast across the Henson 

Creek fault and Keys Gap monocline but that the middle Bloyd sandstone drops less. Northwestward thinning of the intervening Late Mississippian Fayetteville Shale and Pitkin Limestone as 

well as erosional truncation of the Pitkin Limestone beneath the basal Pennsylvanian unconformity 

(cross Sections A–A' and B–B') takes up most of the difference between flexure of the Mississippian 

and Pennsylvanian reference horizons. This change of unit thickness suggests that the Keys Gap 

monocline-Henson Creek fault structural zone was active as early as the Late Mississippian. In the 

Ponca quadrangle to the north, thickness variations of Upper Mississippian strata as well as overlap 

of the Kyles Landing fault by the Early Pennsylvanian Cane Hill Member of the Hale Formation 

were also recognized (Hudson and Murray, 2003) and were attributed to a latest Mississippian 

phase of tectonic activity (Hudson and Turner, 2014b).

A second N.40°E. trending structural zone that lies about 2 mi to the southeast of the Keys 

Gap monocline is composed of the en echelon Hoghead Creek and Taylor Mountain faults (fig. 4). 

Both Hoghead Creek and Taylor Mountain faults have maximum down-to-the-southeast throw near 

the center of their map lengths, with displacement dying out rapidly at the tips. Narrow 

northeast-trending synclines lie immediately southeast of both faults in their downthrown 

southeastern sides. 

Two additional gentle folds are recognized within the quadrangle. A shallow east-northeast-trending syncline extends from Beckham Creek on the east to Arrington Creek on the western 

edge of the quadrangle and is expressed in structure contours on both Mississippian and Pennsylvanian reference horizons. A small north-northwest-trending domal anticline at the head of Dry Creek 

at the northwestern corner of the quadrangle is defined by a local rise of the top of the Boone 

Formation.

Structural data gathered from ninety faults observed within the quadrangle, most too small to 

portray on the map, show the extent of fault deformation as well as give insight into the causative 

stresses. Sites where faults were observed are coincident with the two northeast-trending structural 

zones, but extend beyond areas where map-scale faults are recognized (fig. 4). The greatest 

frequency of observed small faults cut the middle Bloyd sandstone (fig. 3B) along the structural 

zone containing the Hoghead Creek and Taylor Mountain faults, although the zone of small-scale 

faulting continues to the southwest of the Taylor Mountain fault onto the northern hillsides of Bean 

Mountain. A similar zone of small faults cuts the middle Bloyd sandstone at the southwestern end 

of the Keys Gap monocline; other faults observed along the Keys Gap monocline-Henson Creek 

fault zone mostly cut Boone Formation. 

Faults have a variety of attitudes and slip senses that mostly vary from normal to strike slip 

(figs. 4 and 5A). The most common faults are east-northeast-striking normal faults that dip 

moderately north or south. Northeast-striking faults with dextral sense and west-northwest-striking 

faults with sinistral sense are also present. Two reverse faults too small to map were observed 

southeast of the Hoghead Creek fault (fig. 4) and may accommodate localized shortening during 

formation of its adjacent syncline. Paleostress inversions for thirty-eight faults with known slip 

direction and sense, using the method of Angelier (1990), suggest that most faults formed in 

transtension with a least principal stress axis oriented south-southeast and shallowly inclined but 

with intermediate and maximum principal stress axes flipping between near-vertical and east-northeast and shallow (fig. 5B). This north-south extension that affected strata at least as young as 

Morrowan (fig. 3B) is similar to widespread deformation documented elsewhere in the southern 

Ozark dome that has been attributed to flexure of the southern continental margin during progressive loading of the Ouachita orogenic belt (Hudson, 2000). The recurrent activity of the structural 

zones in this quadrangle is evidenced by their influence on Late Mississippian stratal thicknesses 

and their subsequent focusing of post Morrowan north-south extension as well as the northeast 

trend of these zones. This is common for basement structural weaknesses throughout the mid-continent area (Marshak and Paulsen, 1996), and suggests that these structural zones may overlie 

preexisting Precambrian basement structural weaknesses.

Joints are common in bedrock units throughout the quadrangle. Measured joints (1,221 total) 

are near vertical and distributed in several sets (fig. 5C). The dominant sets strike northeast and 

north. A less prominent joint set strikes northwest. Joint planes within carbonate formations, such 

as the Boone Formation, are commonly enlarged due to dissolution.

ECONOMIC GEOLOGY

Within the quadrangle, lead and zinc were mined from ores of galena and zinc carbonate 

intermittently in the early 1900s as the southern part of the Little Buffalo River district (McKnight, 

1935). Each of three mines (now abandoned) within the quadrangle lies along the Keys Gap 

monocline (fig. 4) and all extracted ore was from the upper part of the Boone Formation in zones of 

fracturing and small faults (McKnight, 1935), indicating that there was a structure control on 

mineralizing fluids. 

The organic-rich Fayetteville Shale (Mf) is a target for shale-oil hydraulic fracturing (fracking) 

farther south in Arkansas with over 6,000 oil and gas well drilled as of 2016 (Arkansas Geological 

Survey, 2016).

INTRODUCTION

This map summarizes the geology of the Murray 7.5-minute quadrangle (fig. 1) in the Ozark 

Plateaus region of northern Arkansas. The Ozark Plateaus region, also referred to as “the Ozarks,” 

is an uplifted region extending south of the Missouri River and extending into northern Arkansas 

and into eastern Oklahoma. Geologically, the map area is on the southern flank of the Ozark dome, 

an uplift that has the oldest rocks exposed at its center, in Missouri. Physiographically, the Murray 

quadrangle is within the Boston Mountains, a high plateau region underlain by Pennsylvanian 

sandstones and shales (Purdue and Miser, 1916). Valleys of the Buffalo River and Little Buffalo 

River and their tributaries expose an approximately 1,600-ft-thick (488-m-thick) sequence of 

Ordovician, Mississippian, and Pennsylvanian carbonate and clastic sedimentary rocks (fig. 2) that 

have been mildly deformed by a series of faults and folds. The Buffalo National River, a park 

which encompasses the Buffalo River and adjacent land that is administered by the National Park 

Service, is present at the northwestern edge of the quadrangle.

Mapping for this study was carried out by field inspection of numerous sites and was compiled 

as a 1:24,000-scale geographic information system (GIS) database. Locations and elevation of sites 

were determined with the aid of a global positioning satellite receiver and a hand-held barometric 

altimeter that was frequently recalibrated at points of known elevation. Hill-shade relief and slope 

maps derived from a U.S. Geological Survey (USGS) 10-meter (m) digital elevation model as well 

as orthophotographs (U.S. Geological Survey, 2003) were used to help trace ledge-forming units 

between field traverses within the Upper Mississippian and Pennsylvanian part of the stratigraphic 

sequence. Strike and dip of beds were typically measured along stream drainages or at well-exposed 

ledges. Structure contours, constructed on the top of the Mississippian Boone Formation (Mb) and 

the base of a prominent sandstone unit within the Bloyd Formation (bu), were drawn based on the 

elevations of field sites on these contacts as well as other limiting information for their minimum 

elevations above hilltops or their maximum elevations below valley bottoms.

DESCRIPTION OF MAP UNITS

[Provincial series for Pennsylvanian and Mississippian units are from McFarland (1988). Due to the 

addition of a shaded relief base, colors on the List of Map Units and the Correlation of Map Units 

may not exactly match unit colors on the map.]

Younger terrace and active-channel alluvial deposits (Quaternary)— 

Unconsolidated sand and gravel of Buffalo River, Little Buffalo River, and 

tributaries. Terrace deposits are principally composed of light-brown fine sand; 

smooth upper surfaces are about 20 feet (ft) above the river. Gravel deposits of 

the active channel are composed of subangular to rounded Paleozoic rock clasts 

of mixed lithology along drainages and are interspersed with bedrock exposures 

too small to show at map scale. Low-lying parts of deposit are subject to periodic 

flooding. As thick as 20 ft

Older terrace and alluvial deposits (Quaternary)—Unconsolidated gravel and sand 

deposits adjacent to Little Buffalo River. Deposits are brown, weathered, 

subrounded to rounded Paleozoic sandstone and subangular chert cobbles in 

brown; silty to sandy matrix about 60 to 100 ft above river. Thickness about 10 ft 

Alluvial deposits (Quaternary)—Unconsolidated alluvial deposits of Henson Creek 

(northeast map area). Light-brown fine sand underlies smooth land surfaces that 

are 10 to 15 ft above level of creek. Deposits as thick as 15 ft 

Colluvial deposits (Quaternary)—Unconsolidated deposits of subrounded to angular 

blocks as large as 20 ft in diameter, commonly in an orange-brown silty clay 

matrix. Blocks are mostly derived from the basal sandstone of the upper part of 

the Bloyd Formation (bu) and the Cane Hill Member (hc) of the Hale 

Formation. Deposits have fan-like morphology and were mapped where 

sufficiently thick to mask typical ledge-flat topography of underlying bedrock. 

Smaller, thinner colluvial deposits elsewhere were not mapped. Thickness 

uncertain but probably more than 10 ft 

Landslide (Quaternary)—Slide blocks of limestone, sandstone, and shale derived 

from the Pennsylvanian Bloyd Formation (bu and bl) through the Prairie 

Grove and Cane Hill Members of the Hale Formation (hf and hc, 

respectively). Upper parts of slides are semi-coherent stratigraphic sequences 

back tilted into hillsides and down-dropped relative to bedrock. 

Atoka Formation (Middle Pennsylvanian, Atokan)—Alternating shale, siltstone, 

and sandstone intervals underlying upper hills of map area. Where exposed, shale 

throughout unit is fissile and dark gray to black. Siltstone is thin bedded with 

ripple cross lamination. Upper sandstone intervals as thick as 10 ft underlie 

highest hills and vary from tan, very fine to fine grained, ripple to planar bedded 

to white, medium to coarse grained, medium planar bedded to thick cross-bedded 

with sparse white quartz pebbles. Lower sandstone interval is about 100 ft thick 

and is homogeneous, tan, thin to medium bedded, fine to very fine grained, and 

forms prominent topographic ledges. Beds are typically ripple cross-laminated, 

and locally bioturbated. Base of unit placed in poorly exposed shale interval that 

forms topographic flat. Thickness is as much as 400 ft

Bloyd Formation (Lower Pennsylvanian, Morrowan)—Interbedded sequence of 

sandstone, siltstone, shale, and limestone beds separated into upper and lower 

parts. Thickness as much as 380 ft 

Upper part—Dominantly sandstone with interbedded siltstone and shale. Upper 

part of sequence contains dark-gray to black shale and siltstone beds that form 

topographic flats interbedded with sandstone beds that form ledges. Upper 

sandstone beds are commonly extensively bioturbated. Upper sandstone intervals 

are 5 to 20 ft thick and vary from orange-brown, fine to coarse grained with local 

quartz pebbles, and medium to thick planar bedded to cross-bedded, fine to very 

fine grained, ripple cross-laminated to planar bedded that is tan to olive and 

locally contain carbonaceous films. A calcite cemented sandstone or bioclastic 

crinoid-bearing limestone is observed at several locations about 140 to 180 ft 

above the basal contact. Base of unit is cross-bedded sandstone as thick as 80 ft 

that commonly forms prominent cliffs although it varies over short distances and 

it grades into less prominent sandstone ledges. Prominent cliff-forming sandstone 

is white to light-brown, fine- to medium-grained quartz arenite that has a sharp 

erosional base and is commonly a composite of several tabular and trough 

cross-bed sets. Sandstone contains local concentrations of white quartz pebbles 

and casts of wood fragments. Where basal interval forms a less prominent cliff, it 

is composed of thin- to medium-bedded sandstone interbedded with siltstone and 

shale. Purdue and Miser (1916) originally assigned rocks of the upper part of the 

Bloyd Formation to the Winslow Formation. Zachry (1977) concluded that the 

basal sandstone was a time-equivalent unit with the Woolsey Member of the 

Bloyd Formation farther west and designated it informally as the “middle Bloyd 

sandstone.” The middle Bloyd sandstone interval comprises the basal interval of 

the upper part of the Bloyd Formation map unit as used here. Thickness is 

200–300 ft 

Lower part—Dominantly shale and siltstone with interbedded limestone and thin 

beds of sandstone. Shale and siltstone are dark gray and fissile to thin; ripple 

bedded. Sandstone is tan, very fine to fine grained, thin bedded with ripple 

marks. Limestone includes medium to thick beds of red-brown conglomerate, 

with clasts of fossil fragments and subrounded sandstone and siltstone. The 

Brentwood Limestone Member at the base of the formation is not mapped 

separately, and is included as being in the lower part of the Bloyd and is a 5- to 

20-ft-thick limestone interval varying from massive gray micrite to reddish-gray, 

coarse bioclastic limestone. Basal contact is conformable and gradational with 

the underlying Hale Formation. Forms moderate to steep slopes and is poorly 

exposed. Thickness varies from 40–180 ft

Hale Formation (Lower Pennsylvanian, Morrowan)—Interbedded sequence of 

sandstone, siltstone, shale, and thin limestone. Thickness 100–200 ft

Prairie Grove Member—Brown to reddish-brown, fine- to medium-grained, 

thick-bedded, calcite-cemented sandstone. Locally contains quartz pebbles at 

base. Beds are planar or cross-bedded, and cross-beds may have bi-directional 

dips. Commonly contains interbeds of reddish-brown coarse bioclastic limestone. 

Weathered sandstone forms rounded surfaces with elliptical cavities as long as 1 ft.

Basal contact with underlying Cane Hill Member is unconformable. Sandstone 

forms steep slopes but may be covered by a colluvial mantle derived from 

overlying units. Thickness 20–60 ft

Cane Hill Member—Interbedded sequence of shale, siltstone, and sandstone. 

Upper part mostly composed of fissile to rippled, thin-bedded, dark-gray shale 

and siltstone but locally contains rippled, thin-bedded, very fine grained 

sandstone interval as thick as 5 ft. Upper part of unit is poorly exposed and forms 

gentle to moderately steep slopes. Lower part is a 10- to 20-ft-thick sandstone 

interval that generally changes downward from olive-brown, very fine grained to 

fine-grained, thin-bedded sandstone with ripple cross-stratification or parallel 

lamination to reddish-brown, medium- to thick-bedded, very fine grained to 

medium-grained sandstone with trough cross-beds. Lower sandstone locally 

contains basal conglomerate lenses as thick as 3 ft containing quartz pebbles and 

subangular to subrounded clasts of sandstone, siltstone, shale, and limestone. 

Sandstone beds throughout unit locally affected by soft-sediment slumps and 

folds. Unit unconformably overlies Pitkin Limestone and Fayetteville Shale. 

Thickness is 80–160 ft 

Pitkin Limestone (Upper Mississippian, Chesterian)—Medium- to dark-gray fetid 

limestone. As unit thickens to the south, upper part of unit is oolitic coarse 

crystalline dark-gray to brown limestone overlain by sandy limestone to calcite 

cemented sandstone horizon. Upper sandy interval, as thick as 20 ft, is restricted 

to southeasternmost areas. Limestone beds may contain abundant crinoids, 

brachiopods, corals, and bryozoan Archimedes. At base, varies from micrite to 

fine grained crystalline limestone with black fissile shale interbeds up to 5 ft 

thick as it grades downward into the Fayetteville Shale. Pitkin generally outcrops 

as a prominent ledge or cliff. Thickness in the northern half of the quadrangle is 

generally between 40 to 60 ft but is absent in the northeastern corner; unit 

thickens to the southeast to as much as 200 ft

Fayetteville Shale (Upper Mississippian, Chesterian)—Composed of black fissile 

shale that is poorly exposed in low slopes. Upper contact includes alternating 

beds of black shale and thin limestone beds as it grades upward into the Pitkin 

Limestone. Lower part of the Fayetteville outcrops along stream gullies where it 

consists of black shale that may contain medium- to light-gray, fetid septarian 

concretions as large as 2 ft in diameter. Basal contact with underlying Batesville 

Sandstone is conformable. Fayetteville Shale is susceptible to landslides. 

Thickness varies from 120 to 220 ft

Batesville Sandstone (Upper Mississippian, Chesterian)—Fine-grained to very fine 

grained, light- to medium-brown, calcite-cemented sandstone with interbedded 

limestone. Upper part of unit is a 3- to 5-ft-thick bed of dark-gray fetid limestone 

with common crinoid fragments and often with oolites. Sandstone of main body 

of unit present in thin to medium planar to hummocky beds that are parallel 

laminated. Sandstone may contain disseminated pyrite framboids that oxidize to 

reddish spots. Basal Hindsville Limestone Member is locally preserved and 

consists of angular white chert clasts in gray limestone matrix, 2- to 4-ft thick, 

indicating an erosional contact with the underlying Boone Formation. The top of 

the Batesville is a common topographic flat that may host sinkholes formed by 

collapse into dissolution cavities in the underlying Boone Formation. Thickness 

is 5−25 ft

Boone Formation (Upper to Lower Mississippian)—Limestone and cherty 

limestone of main body that grade into the basal St. Joe Limestone Member. The 

Boone Formation is a common host of caves and sinkholes. Total thickness is 

380−405 ft 

Main body (Upper to Lower Mississippian, Meramecian to Osagean)— 

Medium- to thick-bedded, chert-bearing bioclastic limestone. Limestone is light 

to medium gray on fresh surfaces and generally coarsely crystalline with 

interspersed crinoid ossicles. A 1- to 3-ft-thick bed of oolitic limestone is locally 

present in upper 10 ft of the Boone Formation. Dense, fine-grained beds of 

limestone are present in upper one-third of unit. Beds are typically parallel planar 

to wavy. Chert content varies vertically and laterally within the Boone and is 

locally greater than 50 percent. Chert is light to medium gray and forms lenticular 

to anastomosing lenses. Chert-rich horizons are generally poorly exposed but 

produce abundant float of white, weathered chert on hillslopes. Chert in 

uppermost part of unit contains common brachiopod molds. Thickness 310−375 ft

St. Joe Limestone Member (Lower Mississippian, Osagean to Kinderhookian)— 

Thin-bedded, bioclastic, medium to coarse crystalline or marly limestone with 

ubiquitous 0.1- to 0.25-in-wide crinoid fragments. Limestone is commonly pink 

to red on fresh surfaces due to hematite in matrix, but color and hematite 

concentrations vary with location. Thin beds are typically wavy in form. Chert 

nodules are uncommon but, where present in upper part, are tabular and reddish. 

Contact with the overlying main body of the Boone Formation is gradational. 

Middle to lower part of the St. Joe Limestone Member may contain shaley 

limestone interval. Base of unit is a 0.5- to 1-ft-thick bed of tan sandstone 

containing phosphate pebbles that marks a regional erosional unconformity. 

Thickness approximately 30−50 ft

Fernvale Limestone (Upper Ordovician)—Medium- to thick-bedded, coarse-crystalline 

bioclastic limestone. Limestone is light pinkish gray to medium gray on fresh 

surfaces and contains abundant 0.1- to 0.4-in-wide cylindrical to barrel-shaped 

crinoid ossicles. Unit only exposed in northwestern map area. Thickness 10−30 ft 

Everton Formation (Middle Ordovician)—Interbedded limestone, dolostone, and 

sandstone. Jasper Member (Glick and Frezon, 1953) forms uppermost part of 

formation and is light-gray finely crystalline to micritic limestone and sandy 

limestone. Below Jasper Member, upper part of the Everton Formation contains 

3- to 20-ft-thick, light- to dark-gray dolostone beds that are interbedded with 

sandstone. Carbonate beds of unit are typically finely crystalline and sparsely 

fossiliferous, and commonly display crinkly laminations. Sandstone is quartz 

arenite with well-sorted, well-rounded, and fine to medium quartz grains. 

Sandstone is present in medium to thick planar beds and is light tan to white and 

cemented by dolomite and (or) calcite. As much as 60 ft of upper Everton 

Formation is exposed in Dry Creek in northwest part of quadrangle, but unit is 

about 300 ft thick to the northeast in the Ponca 7.5-minute quadrangle (Hudson 

and Murray, 2003) 

Lower Ordovician rocks, undivided—Sedimentary rocks shown on cross sections 

only

Qty

Qto

Qal

Qc

Qls

a

bu

bl

hg

hc

Mp

Mf

Mbv

Mb

Mbs

Of

Oe

Ou

1150

1700

6

MAP EXPLANATION

Contact—Solid line. In cross sections only, short dash where location inferred

Normal, right-lateral, strike-slip fault—Ball and bar on downthrown block, arrows 

show relative motion. In cross sections only, short dash where location inferred

Anticline

Syncline

Monocline—Arrow shows direction of dip

Structure contour line of equal elevation—Top of the Mississippian Boone 

Formation (Mb). Hachures point to closed areas of lower values. Contour 

interval 50 ft

Structure contour line of equal elevation—Base of “middle Bloyd sandstone” of the 

upper part of the Pennsylvanian Bloyd Formation (bu). Hachures point to 

closed areas of lower values. Contour interval 50 ft

Control point—Showing elevation (in feet) of the top of the Boone Formation (Mb)

Control point— Showing elevation (in feet) of the base of “middle Bloyd sandstone” 

of the upper part of the Pennsylvanian Bloyd Formation (bu)

Buffalo National River boundary

Shoreline of Little Buffalo River

Strike and dip of bedding

Inclined bedding—Showing strike and dip

Horizontal bedding

Fault movement—In cross sections only. Fault movement away from viewer, minus; 

towards viewer, plus

Location of photographs for fig. 3A and B

1180

1760

CORRELATION OF MAP UNITS 

Qty

Qal Qc Qls QUATERNARY

Qto

Unconformity 

a Atokan 

bu

Unconformity

bl PENNSYLVANIAN

Morrowan 

hg

Unconformity 

hc

Unconformity

Mp 

Mf Chesterian 

Mbv

MISSISSIPPIAN

Unconformity

MeramecianOsagean Mb

OsageanKinderhookian Mbs

Unconformity

Of Upper Ordovician 

Unconformity

Oe Middle Ordovician ORDOVICIAN 

Unconformity 

Ou Lower Ordovician 

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3360 Prepared in cooperation with the

National Park Service