1200

1350

950

1000

950

900

850

800

900

1050

1000

950

1050

1100

1000

950

850

800

800

900

850

900

1150

1200

1250

1000

1300

1350

1400

1450

1500

1100

1050

950

900

850

950

950

1050

1000

950

900

850

900

1000

950

950

900

900

1000

1000

950

1050

1100

900

950

900

950

1000

1050

1000

1000

950

900

950

1000

950

1050

1100

1050

650

700

750

700

750

750

750

750

750

900

800

700

1000

950

950

900

900

950

800

850

900

1000

1050

950

900

950

650

800

850

900

900

850

950

1000

750

700

650

900

900

850

800

850

600

650

900

850

800

900

900

950

1000

1050

950

1000

1050

1100

1150

900

1050

1100

1100

1050

1150

1000

950

950

1000

1000

800

850 900

950

1000

1050

1100

1150

800

850

900

1150

1200

1250

1250

1150

1200

1250

1200

1250

1000

1250

1250

1200

1150

800

1200

1150

1100

1050

1250

1300

1100

1350

1400

1450

1500

1450

850

900

950

1000

1050

1100

1350

1150

1150

1200

1000

950

900

900

1100

900

1300

1300

1350

1100

1150

1200

1200

1250

1250

1150

1350

1300

1300

1250

1200

1150

1150

1400

1300

1250

1400

1500

1450

1200

1150

CLIFF

HANNER

HOLLOW

ANTICLINE

MONOCLINE

SNEEDS

CREEK

DOME

WEST

FORK

MONOCLINE

TOM

THUMB

MONOCLINE

WEB

MONOCLINE

BEE

BLUFF

MONOCLINE

POINT

ADDS

CREEK

MONOCLINE

SAWMILL

MONOCLINE

HOSKIN

CREEK

MONOCLINE

EAST

FORK

MONOCLINE

DAVIS

CREEK

MONOCLINE

YARDELL

MONOCLINE

GROGINS

HOLLOW

SYNCLINE

3 2

6

4

6

6

3

4

4

10

6

11

17

17 24

14

2

36

31

32

4

15

21

45 43 4

52 9

9 8 

10

22

30

12 14

20

18

40

15

7 4

5

5

7

3 5

6

6

6

3

4

6

7

7

10

2

14 6

3

3

8

19

13

15

8 

4

2

38

18

15

4 6

7

12

5

9

6

11 8

9

4

3 

5

7

7 8

4

3

3

6

14

12

3

7

10

3

12

13

5

10

18

3

5

14

36 8

8

11

2

4

11

3

3

8

3

3

6

8 3

20 4

28

7

3

6

3

3

26 4

3

12

5

9

6

18

7 7

4

4

5

2

6

8

7

12

3

5

10

3

3

8

14

5

2

4

3

2

3

8

8

3

2

8 4

5

8 8

8

6

23

7

3

3

7

5

4 6

10

9

14

39

3

13

3

3

3

15

3

5

6

2

4

2 2

4

3

2

12

3

3

5

3

4

5

6

5

3

3

6

9 13

4 4

7

7

7

8

4

5 8

8

5

12

5

4

2

6

8

5

3

7

3

5

2

11

3 4 6

3

12

6

31

25

6

5

4

3

3

17

7

2

4

3

9

2 7

6

9

8

12

2

11

16

4

6

12 21

21 7

4 39

68

34

11

77

10

6

12

41 46

3

2

8

10

9

3

10

16

4

3

3

3

7

4

4

4

3

4

5

5

3

6

7

5

9

3

7

4

9

25 31

3

5

9

3

2 6

6

5

4

4

2

7

4

5

2

2

7

7

14

5

26

2

4

4

3

5

7

7

4

4 3

6

2

2 3

8

2 5

3

2

2

3

4

3

3

5

4

7 5

7

4

5

3

6

4

4

3

11

5

6

14

4

3

14

8

4

9

7

9

18

14

12

5

11

8

11

8

10

6

5

3

5

8

11

10

7

4

5 4

4

3

6

7

7

10

22

3

5

5

7

14

4

6

9

3

4

6

3

3

4

5

17

5

3

5

4

34

6

3

13

3

6

8

8

8

8

5

6 3

6

7

6

16

8

6

3

4

10

3

4

4

3

7 6 16

3

3

12

6

4

6

14

4

4

5

25

3

3

4 8

3

8

3

3

6

6

8

9

9

6

9

3

9

3

2

3

8

7

3

4

4

3

10

2

3

2

7

4

3

2

9

4

5

4

2

7

8

10

6

3

4

4

4

6

7

2

3

3

4

3

3

27

2

3

9

4

4

9

3

5

3

3

5

5 3

2

2

3

4

7

7

3

4

7

2

2

2

5

3

2

4

2

8

8

4

3

5

4

8

7

4

2

2

3

7

5

3

4

8

7

4

4 3

2

9

2

3

8

6

8

9

7

6

4

4

2

4

2

4

6

7

4

2

5

6

8

3

7

8

4

9 4

7

7

3 3

5 4

3

7

6

3 9

5

7

3

5

4

8

7 3

2

6

2

5

5

2

5

3

2

4

9

3

8

7

9

2

4

4

9

6

4

8

8

2

8

6

3

6

8

5

4

8

2

6

4

7 8

2

4

7

4

3 9 5

3

3

5

5

4

2

3

3

3

6

2

4 2 2 3

2

3

14

18

10

22

14

10

24

11

13

12

29 30

14

22

16

10

13

15

13

15

12

15

27

26

25

10

12

14

10

14

11

18

39

24

13

18

17

12

12 11

10

14

10

10

11

10

12 11

4

2

11

Mf

hc

hc

hc

a

bu

bl

bl

hg

hg

bl

bl

bl

bl

bl

bl

bu

bl

bl

hg

hg

hg

hg

hg

bl

bl

bl

bl

bl

bl

bu

bu

bu

bu

bu

bu

bl

hg

hc

hc

hc

hc hc

hc

hc

hc

hc

bu

a

a

a

a

a

a

Mb

Mbv

Mbv

Mbv

Mbv

Mbs

Mbs Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mb

Mb

Mb

Mb

Oeu

Oeu

Oeu

Oel

Oel

Oel

Oel

Oel

Oeu

Oeu

Qty

Qty

Mb

Mbv

Mbv

Mb

a

bl

bl

bl

bl

bl

bl

bl

bl

bl

hg

bl

hg

hg

Mf

Mf

Mf

Mf

Mf

Mf

Mf

bl

bl

hg

hg

bl

bu

hg

hg

hg

bl

bl

hc

hc

hc

hc

hc

hg

hc

hc

hg

hg

bl

bu

bu

bu

bu

bu

bu

hc

hc

hc

hc

hc

hc

hc

hc

bu

bu

bu

bu

bu

bu

bu

bu

hg

hg

hg

bl

hc

bl

hg

hc

bu

hc

a

a a

a

a

hg

hg

hg

hg

hg

hc

hc

Mp

Mp

Mp

Mp

Mfw

Mfw

Mf

Mf

Mf

Mfw

Mb

Mbs

Mbv

Mbv

Mbv

Mbv

Ql

bl

bl

Mfw

Mfw

Mf

Mf

Mf

Mf

Mf

Mf

Mbv

Mb Mb

Mb

Mb

Mbs

Mbs

Mbs

Mb

Mb

Mb

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mfw

Mfw

Mb

Mb

Mbv

Mbv

Mb

Mb

Mbv

Mbv

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbv

Mbv

Mbv Mbs

Mbs

Mbs

Mbs

Mbs

Mb

Mb

Mb

Mbv

Mbv

Mbv

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mbs

Mbs

Mbs

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbs

Mbs

Mbs Mbs

Mbs

Mbs

Mbs

Mfw

Mbv

Mbv

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mbs

Mfw

Mfw

Mfw

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mf

Mbv

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mf

Mf

Mfw Mp

hc

bu

bu

bu

hg

hg

bl

hc

hg hc

hc

hc

bl

bu

hg

bl

bl

hc

hc

hc

hg

bl

Mf

Mfw

Mfw

Mfw

Mp

Mp

Mp

Mf

Mf

Mf

Mf

Mf

Mf

Mf

Mp

Mp

Mp

Mp

Mf

Mf

Mf

Mf

Mfw

Mp

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mbv

Qal

Qal

Qal

Qal

Qal

Qal

Qal

Qal

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oel

Oel

Oel

Oel

Oel

Oel

Op

Ql

Mp Qc

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oel

Oeu

Oeu

Oeu

Oel

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Oeu

Qto2

Qto1 Qto1

Qto1

Qto1

Qto1

Qto1

Qto1

Qty

Qty

Qc

Qty

Qty

Qty

Qty

Qty

Qto1

Qto1

Qto1 Qto1

Qto1

Qto1

Qty

Qty

Qty

Qty

Qty

Qty

Qty

Qty

Qto2

Qtm

Qtm

Qto2

Qto2

Of Qto2

Qto2

Qto1

Qto1

Qto1

Qc

Osp

Osp

Mb

Mb

Mb

Mbs

Mbs

Mbs

Mbs

Of

Of

Op

Mbs

Mbs

Mbv

Mbv

Mbv

Mbv

Mbs

Mbs

Mbs

Mbs

Mbv

Mb

Mb

Mb

Mb

Mb

Mb

Mb

Mf

Mf

Mf

Mf

Mf

Mf

Mf

Mf

Mf

Mbv

Mbv

Mb

Mf

Mf Mbv

Mp

Mp

Mf

Mbv

Mfw

Mp

Mp

Mf

Mbv

Mbv

Mbv

Mbv

Mbv

Mbv

Mf

Mbv

Mf

Mf

Mb

Mb

Mb

Mb

Mb

Mb

Op

Op

Qc

Op

Op

Oc

Of

Oel

Oel

Oel

Oel

Oel

Oeu

Oeu

Oeu

Oel

Oel

Oel

Oeu

Oeu

Oeu

Oeu

Oeu Oeu

Oel Oeu

Oeu

Oeu

Mf

Mf

Mf

Qtm

Qto1

Qc

Qtm

Qtm

Qty

Qty

Qty

Qty

Oeu

Oeu

Oeu

Osp

Osp

Osp

Mbs

Mbs

Mbs

Oeu

Opl Opl

Of

Of

Of

Of

Of

Qtm

Qtm

Qtm

Qtm

Photo 1. View to the northwest of the Steel Creek area (Ponca quadrangle). Buffalo River is flanked on 

the left by grassy, youngest terrace deposit (Qty). Roark Bluff, along the right side of the river, is held up 

by the Newton Sandstone Member of the Everton Formation (Oeu). Photograph by M.R. Hudson, 1998.

Photo 2. View looking north of the base of Big Bluff (Ponca quadrangle) with 

exposures of Powell Dolomite (Op) overlain by Everton Formation, including Newton 

Sandstone Member (Oeu) holding up prominent bluff. Buffalo River is in foreground. 

Photograph by M.R. Hudson, 2012). 

Photo 3. The 209-foot-high waterfall at Hemmed-In Hollow (Ponca quadrangle). 

Powell Dolomite (Op) forms lower part of the slope and is overlain by Everton 

Formation (Oel, Oeu). Photograph by M.R. Hudson, 2012.

Photo 4. View to the east of the Buffalo River with the St. Joe Limestone Member of the Boone Formation (Mbs) 

overlying upper part of Everton Formation (Oeu). Strata have a shallow southeastern dip within the eastern part of 

a graben structure between the St. Joe and the South Braden Mountain faults (Jasper quadrangle). Photograph by 

M.R. Hudson, 2011.

Photo 5. View to south of the confluence of the Little Buffalo River (right) 

with the Buffalo River (Hasty quadrangle). Photograph by M.R. Hudson, 

2010.

Ozark dome

94° 92° 90° 

MISSISSIPPI EMBAYMENT

ARKANSAS

Arkoma Basin

Ouachita Mountains

Boston Mountains

MISSOURI

TENN

MISS

TEXAS

OKLA

KAN

St. Francois

Salem 

Plateau

Springfield

Plateau

Mountains

37°

35°

33°

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

MARSHALL

SIM 2991

MF 2412 MF 2356

OFR 98–116

SIM 2847 SIM 2921 SIM 3074 SIM 3134

BUFFALO

NATIONAL

RIVER

36°

36°15'

35°52’30”

36°07’30”

93°15'

93°30' 92°45'

93°

Compilation map area

0

0

5 MILES

5 KILOMETERS

Figure 1. Location of study area within northern Arkansas, overlapping the west-central part of Buffalo National River. 

Previously published U.S. Geological Survey geologic maps in area (Hudson, 1998; Hudson and others, 2001, 2006; 

Hudson and Murray, 2003, 2004; Hudson and Turner, 2007, 2009; Turner and Hudson, 2010) 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 Ozarks Plateaus region includes Salem and Springfield Plateaus, and Boston Mountains 

physiographic provinces.

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

Geologic Map of the West-Central Buffalo National River Region, Northern Arkansas (West Part)

By

Mark R. Hudson and Kenzie J. Turner

2014

Base from U.S. Geological Survey: Ponca, Ark., 1967; Jasper, Ark., 1967; Gaither, Ark., 1967; 

Harrison, Ark., 1967, Hasty, Ark., 1967

Universal Transverse Mercator (UTM) projection. 1927 North American Datum

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

1000-meter Universal Transverse Mercator grid ticks, zone 15

Buffalo National River boundary modified from the U.S. National Park Service, accessed Aug. 

2014, at https://irma.nps.gov/App/Reference/Profile/2210710.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this information product, for the most part, is in the public domain, it also contains 

copyrighted materials as noted in the text. Permission to reproduce copyrighted items must 

be secured from the copyright owner.

This database, identified as SIM 3314, has been approved for release and publication by the 

U.S. Geological Survey (USGS). Although this database has been subjected to rigorous 

review and is substantially complete, the USGS reserves the right to revise the data 

pursuant to further analysis and review. Furthermore, it is released on condition that neither 

the USGS nor the U.S. Government may be held liable for any damages resulting from its 

authorized or unauthorized use.

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/ 

Publishing support provided by: 

Denver Publishing Service Center

Edit and digital layout by L.J. Binder

Manuscript approved for publication October 16, 2014

To learn about the USGS and its information products visit

http://www.usgs.gov/ 

1-888-ASK-USGS

This report is available at:

http://pubs.usgs.gov/sim/3314

Suggested citation: Hudson, M.R., and Turner, K.J., 2014, Geologic map of the west-central 

Buffalo National River region, northern Arkansas: U.S. Geological Survey Scientific 

Investigations Map 3314, 2 sheets, scale 1:24,000, http://dx.doi.org/10.3133/sim3314. 

ISSN 2329-132X (online)

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

APPROXIMATE MEAN

DECLINATION, 2014 TRUE NORTH

MAGNETIC NORTH

7°

(Geologic Map of the West-Central Buffalo National River Region, Northern Arkansas (East Part))

CALIFORNIA

POINT

FAULT

CARLTON

FAULT

CARLTON

COMPTON

FAULT

CUTOFF

ROAD

FAULT

ELMWOOD

FAULT

ZONE

ELMWOOD

FAULT

ZONE

GAITHER

MOUNTAIN

FAULT

KYLES

LANDING

FAULT

SOUTH BRADEN

MOUNTAIN

FAULT

ST JOE

FAULT

ST

JOE

FAULT

STRINGTOWN

HOLLOW

FAULT

UPPER

FLATROCK

CREEK

FAULT

FAULT

ARKANSAS

MAP LOCATION

CONTOUR INTERVAL 20 FEET

NATIONAL GEODETIC VERTICAL DATUM OF 1929

DATUM IS MEAN SEA LEVEL (Gaither, Ark., Harrison, Ark., and Jasper, Ark.)

Geology mapped by M.R. Hudson 1996–2003, and M.R. Hudson and K.J. 

Turner 2010–2013.

NATIONAL RIVER BOUNDARY

NATIONAL RIVER BOUNDARY

NATIONAL RIVER BOUNDARY

NATIONAL RIVER BOUNDARY

1000

6

EXPLANATION

Contact

Normal fault—Dashed where approximately located, short dash where inferred, 

dotted where concealed; ball and bar on downthrown block

Normal, right-lateral, strike-slip fault—Dashed where approximately located, short 

dash where inferred, dotted where concealed; ball and bar on downthrown block, 

arrows show relative motion

Normal, left-lateral, strike-slip fault—Dashed where approximately located, short 

dash where inferred, dotted where concealed; ball and bar on downthrown block, 

arrows show relative motion

Strike-slip fault, right-lateral offset—Dotted where inferred; arrows show relative 

motion

Reverse fault—Short dash where inferred, dotted where concealed; rectangles on 

upthrown block

Thrust fault—Sawteeth on upper (tectonically higher) plate

Anticline—Dotted where concealed

Syncline—Dotted where concealed

Monocline—Dotted where concealed; arrow shows direction of dip

Line of equal elevation—Showing base of Boone Formation, contour interval 50 ft

Buffalo National River boundary

Shoreline

Strike and dip of bedding

Inclined bedding—Showing strike and dip

Horizontal bedding

Qal

CORRELATION OF MAP UNITS

Mp

Mfw

Mf

Mbv

Mb

Mbs

PENNSYLVANIAN

MISSISSIPPIAN

Unconformity

Unconformity

Ql

Qbx

?

?

Unconformity

Morrowan

Chesterian

Meramecian-Osagean

Osagean-Kinderhookian

bu

bl

hg

hc

Unconformity

Unconformity

Of

ORDOVICIAN

Unconformity

Ocs

Unconformity

Su

Unconformity

Unconformity

Unconformity

Unconformity

Unconformity

Oeu

Opl

Osp

Lower Ordovician

Middle Ordovician

Upper Ordovician

Ludlow–Llandovery SILURIAN

Oel

Qty

QUATERNARY

Qtm

Qto1

Op

Oc

Qc

a Atokan

Qto2

DESCRIPTION OF MAP UNITS

Alluvial deposits (Quaternary)—Unconsolidated silt, sand, and gravel. Active-channel 

gravel deposits are composed of subangular to rounded Paleozoic rock clasts of 

mixed lithology along drainages, and interspersed with bedrock exposures (not 

mapped). Low terraces of light-brown, fine sand to reddish-brown silt are present 

adjacent to streams and underlie smooth land surfaces that are 10–15 ft above 

base-flow level of streams. As thick as 15 ft

Younger terrace and channel alluvial deposits (Quaternary)—Unconsolidated 

sand and gravel of Buffalo River. Terrace deposits are principally light-brown 

fine sand and have smooth upper surfaces that are about 20 ft above the 

base-flow level of river. Channel gravel is subangular to rounded and composed 

of clasts of Paleozoic sandstone, chert, and sparse dolostone and limestone; 

unmapped bedrock exposures are interspersed along channel. As thick as 20 ft

Medial terrace and alluvial deposits (Quaternary)—Unconsolidated sand and 

gravel deposits adjacent to Buffalo River. Deposits are poorly exposed and are 

principally brown-weathered, fine sand but include basal zones of subrounded 

gravel containing pebbles to cobbles of Paleozoic sandstone and chert. Both 

basal strath and upper deposit surfaces are flat to gently sloping and are 30–45 ft 

and 65–100 ft above the base-flow level of river, respectively. Thickness 15–50 ft

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

deposits adjacent to Buffalo River. Deposits are poorly exposed and are principally

lag gravel of brown-weathered, subrounded to rounded, pebble- to cobble-sized 

clasts of Paleozoic sandstone and chert in a sandy matrix, locally overlain by fine 

sand, silt, and clay. Basal strath and upper deposit surfaces are flat to gently 

sloping and are 65–120 ft and 100–160 ft above the base-flow level of river, 

respectively. Thickness 15–50 ft

Very old terrace and alluvial deposits (Quaternary)—Poorly exposed, unconsolidated 

gravel and sand deposits adjacent to Buffalo River. Deposits are principally a lag 

of weathered, rounded to well-rounded clasts of Paleozoic sandstone and chert in 

a sandy matrix. Basal strath and upper deposit surfaces are flat to gently sloping 

and are 130–245 ft and 160–280 ft above the base-flow level of river, respectively. 

Thickness 5–45 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) or 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 as 

great as 60 ft

Landslide (Quaternary)—Large slide blocks of limestone, sandstone, and shale 

derived from the Lower Pennsylvanian Bloyd Formation through the Upper 

Mississippian Fayetteville Shale. Upper parts of slides are semi-coherent 

stratigraphic sequences that are back tilted into hillsides and down-dropped relative 

to bedrock. Lower parts of slides root in deformed lower part of Fayetteville Shale

Remnant block deposits (Quaternary?)—Remnant erosional blocks of Upper 

Mississippian Batesville Sandstone (Mbv) in sinkholes and along faults within the 

underlying main body of the Upper and Lower Mississippian Boone Formation 

(Mb) in eastern part of map area. Deposits are characterized by tabular sandstone 

blocks with moderately rounded edges 1 to 4 ft in diameter and interspersed with 

chert. Deposits interpreted to be related to late-stage karst development

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

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

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

with ripple cross-lamination. Sandstone intervals vary from common tan, very 

fine to fine-grained, ripple to planar bedded to less common white, medium- to 

coarse-grained, medium planar-bedded with sparse white quartz pebbles. 

Thickness as much as 100 ft

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

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

upper parts. Thickness as much as 400 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 intervals are 5–20 ft thick and vary from orange-brown, fine- to 

coarse-grained with local quartz pebbles, and medium to thick planar bedded to 

crossbedded, to tan or olive, fine- to very fine grained, ripple cross-laminated to 

planar bedded. Base of unit is crossbedded sandstone as thick as 80 ft that forms 

prominent cliffs. This basal 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-crossbed sets. Sandstone contains local 

concentrations of white quartz pebbles and casts of wood fragments. Rocks of 

the upper part of the Bloyd Formation were originally assigned to the now 

abandoned Winslow Formation by Purdue and Miser (1916). 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.” Thickness 200–300 ft

Lower part—Sequence of predominantly dark-gray to black shale and siltstone 

with thin beds of sandstone and limestone; poorly exposed under moderate to 

steep hillslopes. Siltstone is medium to dark gray, fissile, and moderately 

bioturbated. Medium beds of rippled, very fine grained sandstone are locally 

exposed as ledges. Coarse bioclastic limestone is reddish gray, weathers dark 

brown, and is present in lower part of sequence. Thickness 90–120 ft

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

sandstone, siltstone, shale, and thin limestone. Thickness 100–180 ft

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

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

base and thin interbeds of fossiliferous limestone. Beds are planar or crossbedded,

and crossbeds may have bi-directional dips. Weathered sandstone forms rounded 

surfaces. Sandstone forms steep hillslopes or ledges that are commonly covered 

by slope debris from overlying units. Thickness 10–60 ft

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

of unit is poorly exposed dark-gray fissile shale and thin-bedded siltstone that 

form gentle to moderately steep slopes. Upper part locally contains rippled, 

thin-bedded, very-fine and fine-grained sandstone intervals as thick as 5 ft. 

Lower part includes 10-ft-thick sandstone interval that changes downward from 

olive-brown, very fine-grained, thin-bedded sandstone with ripple cross-lamination 

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

sandstone with trough crossbeds. Lower sandstone contains sparse casts of wood 

fragments and conglomerate lenses with quartz pebbles and angular to subrounded 

clasts of shale, siltstone, and sandstone. Unit unconformably overlies the Pitkin 

Limestone or Fayetteville Shale. Thickness 80–240 ft

Pitkin Limestone (Upper Mississippian, Chesterian)—Generally medium- to 

dark-gray, fetid limestone; commonly forms a prominent ledge or steep slope. 

Limestone in medium to thick wavy beds varies from micrite at base to coarse 

grained and locally oolitic near top. Limestone beds may contain abundant 

crinoids, brachiopods, corals, and bryozoan Archimedes. Basal contact with the 

Fayetteville Shale is conformable. Thickness 0–100 ft

Fayetteville Shale (Upper Mississippian, Chesterian)—Fine-grained sandstone and 

siltstone of the Wedington Sandstone Member that grades downward into main 

body of black, slope-forming shale. Thickness 10–500 ft

Wedington Sandstone Member—Brown to light-gray, well-indurated, 

calcite-cemented sandstone and siltstone. The Wedington caps a steep slope and is 

commonly separated from the overlying Pitkin Limestone by a topographic 

bench. Sandstone is very fine grained and is present in thick to thin planar beds 

with internal parallel laminations and locally developed low-angle crossbeds. 

Sandstone grades downward into siltstone beds that are ripple cross-laminated and 

bioturbated. The Wedington grades downward into main body. Thickness 0–40 ft 

Main body—Below the Wedington Sandstone Member, the Fayetteville Shale is 

poorly exposed black shale that locally contains thin, rippled beds of olive-brown 

siltstone near its top. The lower part of the Fayetteville crops out along stream 

gullies where it consists of black fissile shale that may contain medium- to 

light-gray, fetid septarian concretions as large as 2 ft in diameter. The Fayetteville 

Shale is susceptible to landslides. Thickness 10–460 ft 

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

fine-grained, light- to medium-brown, calcite-cemented sandstone with sparse 

interbedded limestone. Thin to medium beds are typically parallel laminated; 

low-angle crossbeds common in upper part of unit. Sandstone commonly contains 

burrows on bedding planes and breaks into thin flat blocks. One or more 

discontinuous, 1- to 3-ft-thick, medium- to dark-gray, fetid, fossiliferous 

limestone beds are commonly interbedded with sandstone; limestone beds contain 

crinoids and brachiopods. Both sandstone and limestone beds may contain 2- to 

10-mm-diameter oxidized pyrite framboids that weather to reddish-brown 

spheres. Where stripped of the overlying Fayetteville Shale, the top of the 

Batesville forms topographic flats. Unit hosts sinkholes formed by collapse into 

dissolution cavities in the underlying Boone Formation. Thickness 5–60 ft

Boone Formation (Upper and 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 350–400 ft 

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

common in upper part of unit. Beds of dense, fine-grained limestone are present 

in upper one-third of unit. Beds are typically parallel and planar to wavy, but 

channel fills are locally present in lower part of unit. Chert content varies 

vertically and laterally within the Boone 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 prominent brachiopod molds. Thickness 310–350 ft 

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

Thin- and wavy-bedded bioclastic limestone containing ubiquitous 3- to 

6-mm-wide crinoid fragments in a finely crystalline matrix. Limestone is 

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

varies depending on hematite concentration. Lenticular red to pink chert nodules 

are locally present in upper part. Contact with overlying main body of Boone 

Formation is gradational and marked by increase in chert and thicker beds 

upward. Middle to lower part of St. Joe Limestone Member contains 

greenish-gray shale interbeds. Base of St. Joe is a 0.3- to 8-ft-thick, very fine to 

fine-grained, moderately sorted, tan sandstone containing phosphate pebbles. 

Unit unconformably overlies Silurian rocks, Cason Shale, Fernvale Limestone, 

Plattin Limestone, St. Peter Sandstone, or upper part of Everton Formation. Total 

thickness of member is 10–50 ft

Silurian rocks, undivided (Ludlow to Llandovery)—Medium- to massive-bedded, 

light-pink, light-gray, and red micrite to coarsely crystalline limestone of the 

Lafferty Limestone, St. Clair Limestone, and Brassfield Limestone. Lafferty 

Limestone only observed as a dense micrite whereas St. Clair and Brassfield 

Limestones are more often medium to coarsely crystalline fossiliferous limestone 

and contain pyrite framboids and calcite-filled vugs. Preserved in structural lows 

in the eastern portion of the map area. Cumulative thickness up to 95 ft, although 

no more than 60 ft observed in any one location

Cason Shale (Upper Ordovician)—Green, tan, black, and blue-green, poorly 

exposed, fissile shale and siltstone that is occasionally dolomitic. Contains 

phosphate-replaced fossils and abundant, polished phosphate nodules from sand 

to pebble size and oxidized pyrite framboids. Outcrop limited to eastern part of 

map area. Thickness 0–15 ft

Fernvale Limestone (Upper Ordovician)—Thick- to massive-bedded, coarsely 

crystalline bioclastic limestone. Limestone is light gray to pink on fresh surfaces 

and contains abundant 3- to 10-mm-wide cylindrical to barrel-shaped crinoid 

ossicles in a coarsely crystalline matrix. Thickness 0–20 ft

Plattin Limestone (Middle Ordovician)—Thin- to medium-planar-bedded, 

fine-grained, dense limestone locally interbedded with calcarenite. 

Characteristically, dense, very fine grained, medium-gray limestone that breaks 

with conchoidal fracture and weathers to very light gray, thin, tabular blocks. 

Locally in upper part contains interbeds of laminated, tan to light-gray, 

fine-grained to very fine grained, limey to dolomitic calcarenite as thick as 10 ft; 

calcarenite has fetid odor when freshly broken. Thickness 0–100 ft

St. Peter Sandstone (Middle Ordovician)—Very fine-grained, grayish-yellow 

sandstone interbedded with blue-green siltstone, shale, and sparse dolostone. 

Sandstone is calcite-cemented arenite containing well-rounded quartz grains. 

Upper part of unit, as thick as 25 ft, is sandstone interbedded with blue-green 

fissile shale, thin-bedded siltstone, and sparse 0.5- to 3-ft-thick beds of 

brown-gray, fine crystalline dolostone; shale, siltstone, and dolostone interval is 

commonly marked by zone of slumped sandstone blocks on hillslopes. Main part 

of unit contains a sequence of 1- to 2-ft-thick sandstone beds overlying a massive 

basal sandstone ledge as thick as 20 ft. Bioturbation is common in most 

sandstone beds and includes cylindrical burrows (Skolithos) perpendicular to 

bedding that weather to distinctive straw-like forms. Basal sandstone is 

crossbedded, contains inclined fractures, and discordantly overlies Everton 

Formation. Thickness 0–70 ft

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

sandstone sequence, divided into upper and lower parts. Unit is 250–400 ft thick

Upper part—Interbedded dolostone, sandstone, and limestone. Limestone is finely 

crystalline, light gray, thick bedded, locally fossiliferous, and is present in 

intervals as thick as 20 ft. Dolostone is light to dark gray, finely to medium 

crystalline, laminated and medium- to thick-bedded and commonly contains 

sandstone stringers. Sandstone is arenite composed of well-sorted, well-rounded, 

fine to medium quartz grains. Sandstone is light tan to white in planar, medium 

to thick beds and is variably cemented by dolomite or calcite; sandstone locally 

grades into sandy dolostone or limestone. Limestone interbedded with limy 

sandstone and lesser dolostone at top of unit composes Jasper Member of Glick 

and Frezon (1953). Dolostone and dolomitic sandstone underlying Jasper 

Member make up most of upper part of Everton. Base of upper part of Everton is 

marked by base of Newton Sandstone Member (McKnight, 1935), a planar, 

medium-bedded quartz arenite composed of well-sorted, well-rounded, fine to 

medium quartz grains. Newton Sandstone Member is 10–100 ft thick. Upper part 

of Everton Formation is 110–200 ft thick 

Lower part—Interbedded dolostone, sandstone, and limestone. Limestone is 

restricted to upper part of unit and is interbedded with dolostone and sandstone. 

Limestone is light gray, finely crystalline, thin to medium bedded, commonly 

laminated, and contains sparse stromatolite hemispheres as large as 1 ft in 

diameter. Dolostone, present throughout unit, is light gray to grayish brown, 

finely to medium crystalline, thin to thick bedded, and commonly laminated, and 

it commonly contains stromatolites. Sandstone is light-tan to white quartz 

arenite, composed of well-sorted, well-rounded, fine to medium grains, variably 

cemented by dolomite or calcite. Sandstone intervals, composed of planar, thin to 

medium beds as thick as 6 ft, are present throughout unit. Sandstone also forms 

lenses and stringers within limestone and dolostone intervals. Light- to 

dark-brownish-gray dolostone and sandy dolostone interspersed with sandstone 

are predominant in lower part of unit. Collapse breccia with clasts of planar 

laminated dolostone and dolomitic sandstone is present. Unit is 140–250 ft thick 

Powell Dolomite (Lower Ordovician)—Fine-grained, thin-bedded, argillaceous 

dolostone with dark-gray shale interbeds. Dolostone beds are medium to thin, 

wavy, and commonly laminated and stromatolitic. Yellowish gray on fresh 

surfaces. Weathers to thin, platy blocks. Unit is about 200 ft thick in the only 

complete section exposed in Hemmed-In Hollow in the western part of the area

Cotter Dolomite (Lower Ordovician)—Brownish-gray dolomite with sparse chert 

nodules. Chert composed of concentric, alternating dark-gray and white bands 

within elongate nodules that are concentrated in dolomite beds in the upper part 

of the formation. Only the upper 20–30 ft of unit are exposed along Hemmed-In 

Hollow (Ponca quadrangle) in the western part of the map area

Qal

Mp

Mfw

Mf

Mbv

Mb

Mbs

Ql

Qbx

bu

bl

hg

Of

Ocs

Su

Oeu

Opl

Osp

Oel

Qty

Qtm

Qto1

Op

Oc

Qc

a

Qto2

hc

REFERENCES CITED

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.

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

quadrangles, Boone and Newton Counties, northern Arkansas: U.S. Geological Survey 

Open-File Report 98–116, scale 1:24,000.

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., Turner, K.J. and Bitting, C., 2011, Geology and karst landscapes of the Buffalo 

National River area, northern Arkansas, in Kuniansky, E.L., ed., U.S. Geological Survey Karst 

Interest Group Proceedings, Fayetteville, Arkansas, April 26–29, 2011: U.S. Geological 

Survey Scientific Investigations Report 2011–5031, p. 191. [Also available at 

http://pubs.usgs.gov/sir/2011/5031/.]

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/.]

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

Bulletin 853, 311 p.

Purdue, A.H., and Miser, H.D., 1916, Descriptions of the Eureka Springs and Harrison quadrangles: 

U.S. Geological Survey Atlas, Folio 202, scale 1:125,000.

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/.]

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: Oklahoma Geological Survey Guidebook 

18, p. 61–66.

INTRODUCTION

This report summarizes the geology of the west-central Buffalo National River region (fig. 1) 

in the Ozark Plateaus region of northern Arkansas. Geologically, the region lies on the southern 

flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. Physiographically,

the map area spans the Springfield Plateau, a topographic surface generally held up by 

Mississippian cherty limestone (Purdue and Miser, 1916) and the higher Boston Mountains plateau 

to the south, held up by Pennsylvanian rocks. The Buffalo River flows eastward through the map 

area, enhancing bedrock erosion of an approximately 1,600-ft- (490-m-) thick sequence of 

Ordovician, Mississippian, and Pennsylvanian carbonate and clastic sedimentary rocks that have 

been mildly deformed by a series of faults and folds. Quaternary surficial units are present as 

alluvial deposits along major streams, including a series of terrace deposits from the Buffalo River, 

as well as colluvium and landslide deposits mantling bedrock on hillslopes.

 This report presents a compilation and update of previously published geologic mapping 

for all or parts of eight U.S. Geological Survey 1:24,000-scale quadrangles in the west-central 

Buffalo National River area (fig. 1). For ease of plotting, the physical map is divided into two parts: 

a western part (sheet 1) that consists of the Ponca, Jasper, Gaither, Harrison, and Hasty 

quadrangles. The eastern part (sheet 2) is composed of the Western Grove, St. Joe, and Maumee 

quadrangles. The report makes available a continuous Geographic Information System (GIS) 

database (not divided into western and an eastern parts) for the geology, including the southern 

Gaither and southwestern Harrison quadrangles that were previously only available in printed form 

(Hudson, 1998), and it also includes an area of new mapping for the southeastern part of the 

Harrison quadrangle. The map updates some areas of the previously published maps. Most of these 

updates are in the earliest published maps, the Jasper (Hudson and others, 2001), Ponca (Hudson 

and Murray, 2003), and Hasty (Hudson and Murray, 2004) quadrangles. Changes to previous maps 

were based on both additional field observations and interpretation of 2009 and 2011 lidar (Light 

Detection and Ranging) surveys yielding high-resolution topographic data for the western parts of 

the map area (available at http://earthexplorer.usgs.gov). Additional rock units shown in the Jasper, 

Hasty, and Ponca quadrangles reflect (1) subdivision of the Middle Ordovician Everton Formation 

into upper and lower parts that have hydrogeologic significance (Hudson and others, 2011), (2) addition 

of Middle Pennsylvanian Atoka Formation on highest ridge crests of the Jasper quadrangle to match 

its distribution on the Ponca (Hudson and Murray, 2003) and the nearby Boxley (Hudson and 

Turner, 2007) quadrangles, and (3) recognition of a series of Quaternary terrace deposits associated 

with older, higher positions of the Buffalo River. Additional elevation control points on upper and 

lower contacts of the Boone Formation allowed modification of structure contours for the base of 

the Boone Formation; locally, Boone Formation contacts were modified to match changes to this 

structure contour model. Unit contacts in southern and southwestern edges of the Ponca quadrangle 

were modified to match field constraints available within adjacent Boxley (Hudson and Turner, 

2007) and Murray quadrangles (Hudson and Turner, unpub. mapping). In the context of available 

high-resolution lidar topographic data, contacts for ledge-forming Upper Mississippian and 

Pennsylvanian units were inspected in areas between field traverses and modified, where needed, to 

match their typical topographic expression. Likewise, fault lines within the Ponca and Jasper 

quadrangles were examined between field-site locations and modified to align with truncations of 

topographically expressed rock units, where obvious.

More detailed descriptions of geologic features and processes for the area are included in the 

text materials that accompany the original maps (fig. 1) incorporated into this compilation.

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Map 3314

Sheet 1 of 2