Digital Geologic Quadrangle Map Arkansas Geological Survey Snowball Quadrangle, Arkansas Bekki White, State Geologist and Director DGM-AR-00800

Geologic Map of the Snowball Quadrangle, Searcy County, Arkansas Angela K. Chandler and Scott M. Ausbrooks

(WESTERN GROVE) 2003 7456 III SW SNOWBALL QUADRANGLE UNITED STATES Revised 2015 ARKANSAS

DEPARTMENT OF THE INTERIOR 7.5 MINUTE SERIES (TOPOGRAPHIC) 7456 II SW

(MAUMEE) GEOLOGICAL SURVEY 7456 III SE

5 5

92°52'30" 5 000m 5 514 R 18 W R 17 W 516 (ST. JOE) 518 47' 30" 519 1 770 000 FEET 21 A 22 92°45' 12 ^ E 13 50' ^ 36°00' 36°00' Mb Osp Ofp Mbvm Old terrace and alluvial deposits (Quaternary) - Fayetteville Shale (Upper Mississippian, Chesterian) - A

Correlation of Map Units Qto1 Unconsolidated gravel deposits on ridges above the Buffalo Mf black fissile clay shale. Alternating beds of micrite with shale ^ River. Deposit consists of coarse sand to cobble sized occur in the upper portion of the formation. Black chert is Stratigraphic Column sub-angular to rounded chert and sandstone. It is located common the micrite. The micritic beds in the upper portion of Ofp Mbvm Mb Qat Qty Qls approximately 80-100 ft. (24-30 m) above the river and ranges this unit form resistant and sometimes steep ledges. Septarian ^ up to 160 ft. (48 m) above the river. Thickness unknown. concretions are present near the base of the shale. Very thin 3983000m N 3983 fine-grained sandstones are interbedded within the lower Qtm Very old terrace and alluvial deposits (Quaternary) - portion of the shale. The Fayetteville Shale is conformable with

Mb 10 Holocene System Stage Formation Mbvm 6 Su Qto2 Unconsolidated gravel deposits on ridges above the Buffalo the underlying Batesville Sandstone. Approximately 200-240

o Qto1 Pleistocene Quaternary o River. Deposit consists of coarse sand to cobble sized ft. (60-73 m) thick. 1700 "middle Bloyd Bloyd Su o sub-angular to rounded sandstone and chert. It is located 4 sandstone" Formation Qtm Qto2 approximately 200 ft. (60 m) above the river. Thickness Batesville Formation (Upper Mississippian, Chesterian) - A } 500 o5 unknown. Mbvm very fine to medium-grained, sub-angular, moderately sorted, 1600 ^ Unconformity iron-cemented sandstone. Thin to medium bedded. Light Q 1 T 16 N to brown to cream-colored on fresh surface. Weathers light to Qto2 Bloyd Formation (Lower , Morrowan) - In this 3982 dark gray. The Batesville Sandstone is unconformable with the T 15 N *bm 1500 T 16 N quadrangle, the individual members within the Bloyd Formation Boone Formation. Approximately 10 - 60 ft. (3-18 m) thick. Mbvm Ofp Qtm cannot be recognized because the Brentwood and Kessler Hindsville Member - A thin-bedded, fine to Witts Springs Formation Unconformity are either missing or have become shaly and sandy. coarsely-crystalline limestone. Light to dark gray on fresh 1400 Qtm Su There are no "marker zones" to divide the section into the Qty 600 000 surfaces but generally weathers light gray or brown. Typically Morrowan recognizable members known from the type section in northwest has a strong petroliferous odor on freshly broken surface. The Qtm FEET *w Pennsylvanian Qto1 T 15 N Arkansas. Therefore the Bloyd Formation is divided informally limestones are fossiliferous and or/oolitic, contain pyrite and 400 Morrowan Qty into lower and upper parts (Hudson et al., 2001) separated by 1300 Unconformity are locally interbedded with thin layers of clay shale and thin ^ the "middle Bloyd sandstone" Zachry and Haley, 1975. The beds of siltstone to fine-grained sandstone. Pennsylvanian Cane Hill Hale Qto1 upper part of the Bloyd is not present in this quadrangle. The Moorefield Formation (Upper Mississippian, Meramecian) - 1200 *hc lower part of the Bloyd is equivalent to the Witts Springs Member 3981 3981 Silty shales with interbedded very thin to thin siltstones. The Formation Qtm Formation in this area. Approximately 240-340 ft. (73-103 m) shaly zones are usually dark gray to black on fresh surfaces } Mb Unconformity thick. but weather gray-green. The siltstones are dark gray to brown 1100 "middle Bloyd sandstone" - A thin to massive, medium- to on fresh surfaces but weather light gray to buff color. 0 - Imo interval *bm Qty coarse-grained, cross-bedded quartz- or iron-cemented approx. 10 ft. (3 m) thick. Qto2 Mi sandstone with sub-angular to sub-rounded quartz grains. 1000 Reddish, gray, or light tan on fresh surfaces but weathers brown 300 ^ Mp Chesterian to orange-brown due to iron content. The cross-bedded Qto2 Boone Formation (Lower Mississippian, Osagean and Mb packages can be up to three feet thick and locally overturned. Mb - Coarse-grained fossiliferous and fine-grained Pitkin Limestone Mf Kinderhookian) 900 Contains abundant lycopod and rounded quartz pebbles. limestones interbedded with anastomosing and bedded chert. 39 Qt 1 39 This sandstone forms a prominent bluff throughout this 80 o Qto1 80 Mississippian Light to medium gray on fresh surfaces but weathers dark gray. Mbvm quadrangle and separates the upper from the lower part of the Qto1 Meramecian The chert varies in color from light gray to dark gray. Springs 800 Qtm Qtm Bloyd Formation. A pebble clast conglomerate is present at the and sinkholes are abundant. In this area, the Boone Mbvm Unconformity base of this sandstone. Unconformable with the lower part of Qtm Formation exhibits an undulating topography that tends to form the Bloyd Formation or the Witts Springs Formation. steep hillsides separated by ravine-like drainages.

^ 700 Chesterian Fayetteville Shale Mb Osagean Approximately 80-120 ft. (24-36 m) thick. Approximately 120 - 400 ft. (36-122 m) thick. Kinderhookian - A medium-grained thin-bedded 200 Qto1 St. Joe Limestone Member Unconformity Witts Springs Formation (Lower Pennsylvanian, Morrowan) crinoidal limestone containing very thin shaly limestones. 600 *w Glick et al., 1964, gave this name to a sequence of rocks in the Dark-gray to reddish in color but sometimes with green mottling 57'30" Qtm 57'30" Batesville Formation Snowball Quadrangle equivalent to the Prairie Grove Member of on fresh surfaces. Commonly weathers medium to dark gray. 39 39 Moorefield Formation 79 79 S Silurian the and the entire Bloyd Shale (Formation) of Qtm ^ Locally contains phosphate nodules near the lower contact. 500 the type Morrowan region northwestern Arkansas. In their Approximately 0-approx. 7 ft. (2 m) thick Meramecian Unconformity definition of this unit, they identified the first massive quartz Basal sandstone - A fine to medium-grained, moderately sorted, Mississippian Qty Mbvm pebble sandstone they encountered above the Witts Springs as sub-rounded to rounded, iron or quartz-cemented sandstone. 400 Ofp Upper the . Subsequently, the "middle Bloyd White to light gray and tan on fresh surfaces with a salt and Boone Formation Mb sandstone" which is not present in the type area of the Bloyd pepper appearance but locally blotchy due to iron staining. 100 Middle Formation in northwestern Arkansas was identified in Weathers tan to white. Thin to thick bedded and typically seen 300 ^ Unconformity Ordovician Mbvm north-central Arkansas by Zachry and Haley in 1975. The as float. Contains phosphate pebbles and angular white and "middle Bloyd sandstone" is present above the Witts Springs Osp light gray chert fragments. This unit yields abundant Formation in the Snowball Quadrangle instead of the Atoka . Unconformable with the Fernvale Limestone or 200 3978 39 Mb 78 Formation. Therefore the Witts Springs Formation is equivalent Silurian units. 0- approximately 1 ft. (.3 m) thick.

to the Prairie Grove Member of the Hale Formation and the Kinderhookien/Osagean lower part of the Bloyd Formation in north central Arkansas. Qa t - A reddish-gray coarsely- 100 A blocky sandstone unlike the Prairie Grove is present above Undifferentiated (Silurian) Silurian Silurian/Fernvale-Plattin ^ S crystalline limestone and gray fossiliferous medium- crystalline the Cane Hill. The Prairie Grove is equivalent ot the base of the /Ordovician limestone. Thin to medium bedded with stylolites along bedding Witts Springs Formation. The Witts Springs is underlain by the 0 m 0 ft. St. Peter Sandstone planes. The reddish-gray coarsely-crystalline limestone contains Cane Hill Member of the Hale Formation and overlain by the Mp calcite vugs and green-clay partings and plugs. 0- approx. 15 "middle Bloyd sandstone" and strata equivalent to the upper ft. (0-4 m) thick exposed. Introduction part of the Bloyd Formation. The Witts Springs Formation can 3977 Ù Mbvm hc be divided into two parts - a main body and a lower sandstone. - A medium- to cherty M f The lower sandstone was not mapped separately due to a 40 Fernvale Limestone (Upper Ordovician) calcareous limestone sandstone This map illustrates the surface geology of the Snowball quad- Ofp coarsely-crystalline crinoidal limestone. Medium to thick to limestone sandstone Mbvm rangle. This quadrangle was previously mapped at a 1:62,500 foot contour interval. Approximately 140-360 ft. (42-109 m) 7455 I NW massive bedded. White to light gray with a pink to reddish tint

(EULA) thick. 7455 IV NW IV 7455 (MARSHALL) scale by Glick and Frezon in 1965 and Haley in 1976 for the Geo- or mottling on fresh surfaces but weathers dark gray. Contains logic Map of Arkansas. From 2002-2003, this quadrangle was Main body - Consists mostly of thin- to medium-bedded Ùbm sandstone and interbedded clay shale. The sands are very fine- nautiloids, barrel-shaped , and that are Qls mapped for the National Cooperative Geologic Mapping Program accentuated on a weathered surface. Commonly contains through STATEMAP. During 2014-2015, the terrace deposits to medium grained and commonly rippleb bedded near the top pyrite. Locally cross-bedded when beds are massive. ripple-bedded interbedded cross-bedded clay shale along the Buffalo National River were mapped with funding of the unit. Calcareous fine- to medium-grained fossiliferous Commonly weathers to rounded masses that are usually friable. sandstone/shale sandstone/shale sandstone provided by the National Park Service. Approximately 17.5 miles sandstones with sub-angular to rounded grains are present and contain clay pebble clasts and fine to coarse quartz 0- approx. 5 ft. (0-1.5 m) thick. of the Buffalo National River are located in this quadrangle and - A thin- to thick- Ù pebbles. Gray on fresh surfaces but weathers brown or dark Plattin Limestone (Middle Ordovician) unconformable surface 3976 w 3976 are managed by the National Park Service. gray. bedded micritic limestone that locally displays a sugary texture. Mp Approximately 1700 feet (518 meters) of Middle Ordovi- Light gray to dark gray on fresh surfaces and weathers white to Ì cian to Morrowan-age strata crop out in this area. The Middle Lower sandstone - A massive coarse-grained iron-cemented sandstone with sub-angular to sub-rounded quartz grains. dark gray. A dolomitic interval is present at the top of the Ordovician St. Peter Sandstone is present only in the northwest- formation. Unconformable with the St. Peter Sandstone in this Qls ern corner of the map where it is upthrown by a fault. Middle Sometimes friable. White to yellow on fresh surfaces but weathers light brown. Contains plant fragments, iron banding, quadrangle. Approximately 5-15 ft. (1.5-4 m) thick. Mbvm and Upper Ordovician and Silurian limestones are present locally along the Buffalo National River. The Lower Mississippian stylolites, and pock marks. This unit has a blocky appearance and forms a prominent bluff on the east side of Point Peter St. Peter Sandstone (Middle Ordovician) - A thin- to thick- Mbvm Boone Formation forms the Springfield Plateau surface on the Osp bedded very fine- to fine-grained sandstone. White to green on majority of the quadrangle. Upper Mississippian to Morrowan Mountain. A dark-gray shale pebble conglomerate is present at References the base of the sandstone. Unconformable with the Cane Hill fresh surfaces but weathers a light gray-green to brown. Green sandstone, shale, and limestone form steep knobs and slopes on shale clasts are present which weather to give the sandstone a 39 39 Member of the Hale Formation. 0- approx. 30 ft. ( 0-9 m) thick. 75 75 the edge of the Boston Mountains escarpment in the southern green color. Contains a calcite cement but when leached leaves Adams, G.I., Purdue, A.H., Burchard, E.F., and Ulrich, Mp half of the quadrangle. sandstone friable. The quartz grains are rounded. Green E.O., 1904, Zinc and lead deposits of northern Arkansas Qls Quaternary terrace and alluvium deposits are present in Hale Formation (Lower Pennsylvanian, Morrowan)- The Hale siltstones and shales are interbedded with the sandstone. with a section on the determination and correlation of Mb the valley of the Buffalo National River and its tributaries. Two Formation consists of two Members; the Prairie Grove Member Contains vertical trace fossils referred to as Scolithos by Adams formations: U.S. Geological Survey Professional Paper, no. 5 Ìo terrace levels are well developed along the river: a younger and a and the Cane Hill Member. Only the Cane Hill Member is 24, 118p. et. al. 1904, that weather to resemble icicles in cross-section 55' 55' Mp medial. Older terraces are located 80-160 (24-49 meters) feet present in this quadrangle. The base of the Witts Springs view. Unconformable with the Everton Formation. Glick, E.E., Frezon, S.E., and Gordon, M.Jr., 1964,Witts Springs above the river in most meander bends. Very old terrace deposits Formation is equivalent to the Prairie Grove Member. Approximately 80 ft. (120 m) thick. Formation of Morrow age in the Snowball quadrangle, M f are preserved locally approximately 200 feet (61 meters) above Cane Hill Member - A gray to black fissile clay to silty shale 15-minute series, north-central Arkansas: in Contribu- the river. *hc containing iron nodules and small limonitic box work tions to stratigraphy, U.S. Geological Survey Bulletin Ùbm fragments. Varies from black to darkgray on fresh surfaces and 1194-D, p. D1-D16. 39 39 74 w 74 light gray and light orange-brown on weathered surfaces. Glick, E.E. and Frezon, S.E., 1965, Geologic map of the Snowball Thin-bedded ripple-marked siltstones and sandstones are quadrangle, Newton and Searcy Counties, Arkansas: U.S.

^ present above the clay shale. Trace fossils are abundant. Geological Survey, Geologic quadrangle maps of the United Unconformable with the Imo interval. Approximately 160- 200 States, Map GQ-425, 1 sheet, 3 p. Mbvm Mb ft. (48-60 m) thick. Haley, B.R., 1976, Geologic map of the Snowball quadrangle, 15-minute series; Arkansas Geological Survey Geologic Worksheet, 1 sheet. Description of Map Units Imo interval (Upper Mississippian, Chesterian) - Consists of Hudson, M.R., Murray, K.E., and Pezzutti, D., 2001,Geology of Ùhc Mi limestones interbedded with clay shale. The limestones are Qa t the Jasper quadrangle, Newton and Boone Counties, Mb fossiliferous and reddish on weathered surfaces. The shale is Arkansas: U.S. Geological Survey Miscellaneous Field 3973 3973 Landslide deposits (Quaternary) - Mostly blocks of sandstone dark gray on fresh and weathered surfaces. A 5-20 ft. (1.5-6 m) Studies Map MF-2356. Qls derived from Morrowan units. Also contains shale slumps from thick sandstone is present at the base of the unit. It is thin- to Mp Zachry, D.L. and Haley, B.R., 1975, Stratigraphic relationships Morrowan and upper Mississippian units. thick bedded, fine grained, cross-bedded, and contains Mp between the Bloyd and Atoka Formations (Pennsylvanian) Ql stylolites, plant fragments, and iron banding. Conformable s of northern Arkansas: in Contributions to geology of the Mbvm Alluvium and terrace deposits (Quaternary) - Unconsolidated with the Pitkin Limestone. Approximately 160 ft. (48 m)thick. Arkansas Ozarks, Arkansas Geological Commission, T 15 N Qat clay, silt, sand, and gravel including deposits on one or more Miscellaneous Publication 12, p. 96-106. Ùhc terrace levels in small streams and tributaries to the Buffalo Pitkin Limestone (Upper Mississippian, Chesterian) - A fine- 570 000 M f River. Approximately 5-20 ft. (1-6 m) is exposed in gravel bars Mp to coarsely-crystalline often fossiliferous limestone containing FEET T 14 N M i along creeks and tributaries to the Buffalo River. crinoidal fragments, Archimedes , gastropods, coral Ùw T 15 N (rugose and colonial), and ooliths. Varies from light gray to 39 72 M i T 14 N Young terrace and active channel deposits (Quaternary) dark gray on fresh surfaces but typically weathers light or M f Mp Qty Unconsolidated clay, silt, sand, and gravel in gravel bars and medium gray. Medium to massive bedded. Commonly has a sandy point bar deposits along the Buffalo River. Primarily petroliferous odor on freshly broken surfaces. A black shale is Mp clay, silt, and sand in youngest terrace above the river. The present at the top of the Pitkin just beneath the Imo interval at Acknowledgments: This map was produced for STATEMAP, Mbvm tops of terraces are generally hummocky and tree-covered but a few localities. No fossils were found from this shale interval. Cooperative Agreement Award 02HQAG0017, a Ù can be flat and commonly dissected by tributaries. Conformable with the Fayetteville Shale. Approximately matching-funds grants program with the US Geological A' 12 Mp hc o Approximately 20-30 ft. (6-9 m) thick. 140-180 ft. (42-54 m)thick. Survey under The National Cooperative Geologic Mapping Program in 2003. In 2014-2015 the AGS mapped terrace 5

o Ùw Medial terrace and alluvial deposits (Quaternary)- deposits along the middle section of the Buffalo National ^ Qtm Unconsolidated clay, silt, sand, gravel, and cobbles along the River through a National Park Service contract. Thanks for

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71 39 000m ^ 71 N Buffalo River. The contact with the underlying young terrace is Corbin Cannon and Daniel Rains for their assistance with located at a riser that is approximately 15-20 ft. (4-6 m) high mapping the terrace deposits. Special thanks to the National and usually coincides with the edge of the riparian zone along Park Service, U.S. Forest Service, Game and Fish Qls Mb Mbvm the river. This terrace is located approximately 40 ft. (12 m) Commission, and to private landowners who graciously above the river and ranges in thickness from 20-60 ft. (6-18 m). allowed access to their property.

Mp w ^ M f Ùbm Mp Limitations: This map, like all geologic maps, is based on Ùhc M f interpretations which were made from the data available at M f the time it was created. As work continues and new data is 3970 Mp Symbols Ùw Ùhc Topographic map of the Snowball quadrangle collected, the contacts and structures depicted on this map may be changed. 35°52'30" INTERIOR - GEOLOGICAL SURVEY, RESTON, VIRGINIA - 1981 35°52'30" 512 5 R 18 W R 17 W 50' 516 518 519 520 13 1 750 000 FEET (WITTS SPRINGS) 47'30" 5 000m 92°45' showing location of data collection points. 92°52'30" 7455 IV SE 22 E Contact (CANAAN) For the latest edition of this and other AGS maps and 7455 I SW Normal fault - ball and bar on publications, please call Publication Sales at 501-296-1877, (MOORE) or visit the Vardelle Parham Geology Center, 3815 West 7455 IV SW downthrown side. Dashed where Roosevelt Road, Little Rock, Arkansas 72204. This map is The topographic base is a collarless Digital Raster 0 51’ inferred. Dotted where concealed. Graphic (DRG). The DRG is a scanned image of a Secondary highway also available on our website at: U.S. Geological Survey standard series topo- http://www.geology.ar.gov/geologicmaps/dgm_24k.htm. graphic map published in 1980. Light duty road 40 Inclined bedded showing Suggested citation: Unimproved road strike and dip 10,000-foot grid based on Arkansas coordinate Chandler, A.K. and Ausbrooks, S.M., revised 2015, Geologic system, north zone. Contour Interval 40 Feet Gravel pit map of the Snowball quadrangle, Searcy County, Arkansas: Quadrangle Location Arkansas Geological Survey Digital Geologic Map, 100-meter Universal Transverse Mercator grid National Geodetic Vertical Datum of 1929 Quarry Joint Frequency DGM-AR-00800, 1:24,000. ticks, zone 15 shown in blue. 1927 North Ameri- Approximate mean can Datum. declination 2015 N

N

14

12

315 A A’ 315 45 45

10 2400 2400 Point Peter Mountain 8

2200 2200 6

Ùbm 4 2000 2000 2

12 14 10 90 6 2 4 8 2 4 10 8 6 12 1800 1800 270 14 90

Ùw 2

1600 1600 4

Ùhc 6 1400 1400

8 Mp 1200 1200 10

135 Buffalo River Mbvm 12 Mill Creek White Hollow Fault Mbvm 225225 135 Mbvm Mf 1000 1000 14

Qto1 N = 51 Qtm 800 800 Mb Qty 180 Ofp Qat Mb Mb N=51 S 600 S Pre - Mb? Pre - Mb? 600 $ Rose diagram of strike frequency of joints recorded within the Snowball quadrangle. Map and cross-section digitized by Walter K. Mayfield, Sea Level Sea Level Jerry W. Clark, and Brian Kehner. SCALE Horizontal: 1 inch = 200 feet Vertical: 1 inch = 500 feet (exaggeration: 4X)