2

U.S. DEPARTMENT OF THE INTERIOR SCIENTIFIC INVESTIGATIONS MAP 2847 U.S. GEOLOGICAL SURVEY Version 1.0

3 A 1370 CORRELATION OF MAP UNITS (Upper Mississippian, Chesterian)—Fine-grained Contact mapped the eastern and western parts of this system as separate grabens. This study 1440 1260 1300 sandstone and siltstone of the Wedington Sandstone Member that grades 88 illustrates that the northern bounding fault is continuous across the area, with a curvilinear 1380 1420 1400 Qty downward into main body of black, slope-forming shale. Thickness varies 60 Normal fault—Showing fault dip (arrow) and rake (diamond-headed arrow) map trace. McKnight (1935) called the eastern extension of this northern fault the St. Joe 1450 1340 Mb Ql QUATERNARY where known. Bar and ball on downthrown side. Dashed where 1320 Mf Qtm from 250 to 370 ft fault and that name is adopted here. The southern boundary of the graben system within Mfw Wedington Sandstone Member—Brown, well-indurated, calcite-cemented approximately located the quadrangle is formed by two normal faults that partly overlap in sec. 7, T. 16 N., R. 19 1490 1050 QTto sandstone and siltstone. The Wedington caps a steep slope and is Normal, right-lateral, strike-slip fault—Bar and ball on downthrown side. W. Where observed, the main planes of faults forming the graben system dip steeply 950 1420 TERTIARY(?) 1290 1325 Mbv separated from the overlying Pitkin by thin black shale that Dashed where approximately located. In cross section A–A', A, movement (72°–83°); where slip striations have been preserved on these faults or nearby smaller faults, 1320 1340 Unconformity Mf 1335 commonly forms a bench. Sandstone is fine grained to very fine grained away from viewer; T, movement toward viewer they mostly have high rake angles that indicate a predominant normal sense of slip (fig. 3A). 1270 Mb 2 900 ၧbu and is present in thick to thin planar beds with internal parallel laminations Strike-slip fault, right-lateral offset Strata within the graben system reach their maximum depth beneath and just west of 14603 and locally developed low-angle crossbeds. Sandstone grades downward Braden Mountain, and they rise to shallower levels both to the east where the southern Mb Unconformity into siltstone beds that are ripple cross-laminated and bioturbated. The Syncline boundary faults overlap and to the west where the graben merges with the northeast-striking East Fork monocline 1325 Wedington grades downward into main body. Thickness 25–33 ft Carlton fault zone on the adjacent Jasper quadrangle (Hudson and others, 2001). The 3 1400 ၧbl Mf Monocline 2 Morrowan Main body—Below the Wedington Sandstone Member, the middle part of western part of the graben system was called the Braden Mountain graben by Hudson 4 Mbv ၧhg the Fayetteville Shale is black shale that is rarely exposed; local topographic 900 Line of equal elevation drawn on base of Boone Formation—Contour (1998). The 260-ft thickness of the Cane Hill Member of the preserved flats in this interval suggest the presence of more resistant rock, like a thin interval 50 ft within the graben at Braden Mountain is much thicker than its 80–140 ft thickness 1310 3 Unconformity sandstone that is exposed about 100 ft below the Wedington Sandstone preserved elsewhere in the quadrangle, suggesting that the graben was active as a growth 2 950 Horizontal bedding ၧhc Member on east side of Pinnacle Mountain. The lower part of the structure during Early Pennsylvanian deposition of the Cane Hill Member. 27 Fayetteville crops out along stream gullies, where it consists of black fissile 2 The northeast-striking Stringtown Hollow fault and Upper Flatrock Creek fault have 1370 ၧ Mf Inclined bedding—Showing strike and dip 6 bu throws that are down to the northwest and southeast, respectively, but it is likely that these 1320 Unconformity shale that may contain medium- to light-gray, fetid septarian concretions as ၧbl large as 2 ft in diameter. The Fayetteville Shale is susceptible to landslides. sample locality faults have components of right-lateral strike slip movement in addition to vertical ၧ bu Mfw 1350 Mp Thickness varies from 230 to 350 ft movement. The down-to-the-northwest sense of throw on the Stringtown Hollow fault Ql 1240 6 1370 Mbv Control point showing elevation (in feet) on lower or upper contact of Mp Mfw Batesville Sandstone (Upper Mississippian, Chesterian)—Fine-grained to where it crosses the Buffalo River is the opposite of its sense on the Jasper quadrangle to Mbv Boone Formation 3 3 ၧbl Chesterian very fine grained, light- to medium-brown, calcite-cemented sandstone with the southwest (Hudson and others, 2001), but it is common for fault zones with dominant 1360 Mf sparse interbedded limestone. Thin to medium beds are typically parallel strike-slip displacement to change sense of throw along their length (Sylvester, 1988). The STRATIGRAPHY Mp laminated; low-angle crossbeds common in upper part of unit. Sandstone main fault plane for the Stringtown Hollow fault was not directly observed within the 11 1270 ၧhg Mbv MISSISSIPPIAN ၧhc 12 950 1350 commonly contains burrows on bedding plane surfaces. Sandstone breaks quadrangle, but small left-lateral faults with northwest strike that were observed at one Mfw The study area preserves a 1,600-ft-thick record of early and late Paleozoic deposition ၧhg 10 1300 Unconformity into thin flat blocks. One or more discontinuous, 1- to 3-ft-thick, medium- location within the fault zone (lat 36°3.23' N., long 93°6.92' W.) are interpreted to be 1360 on what is now the southern margin of the North American continent. Stages for 2 to dark-gray, fetid, fossiliferous limestone beds are locally interbedded with antithetic shears to the main, right-lateral fault zone. The Upper Flatrock Creek fault has ၧbu ၧbl Meramecian- Pennsylvanian and Mississippian units are from McFarland (1988). 2 Mb sandstone; limestone beds are fossiliferous and contain and consistent down-to-the-southeast throw as great as 100 ft. It is at least 5 mi long and it 1340 1410 Osagean The Middle Ordovician Everton Formation is a heterogeneous sandstone and carbonate Oe 11 1405 Osagean- . Both sandstone and limestone beds may contain 2- to 10- continues to the northeast off the edge of the quadrangle. The southwest extension of the Mf Mbs unit that Suhm (1974) interpreted to have been deposited in barrier island and tidal flat ၧhc 1000 Kinderhookian mm-diameter oxidized pyrite framboids that weather to reddish-brown Upper Flatrock Creek fault is uncertain past sec. 35, T. 17 N., R. 20 W. Where the Upper 2 1370 depositional environments. The Everton Formation is discontinuously overlain by the 4 Unconformity spheres. The Batesville commonly forms a topographic ledge that forms Flatrock Creek fault crosses Davis Creek, a syncline is developed within Batesville Sandstone 1005 1360 1360 Middle Ordovician St. Peter Sandstone and Plattin Limestone and the Upper Ordovician Upper Flatrock Creek fault Upper small waterfalls along streams. Where stripped of the overlying Fayetteville on the downthrown, southeastern side of the fault. 1400 Of Fernvale Limestone. Identification of an inlier of St. Peter Sandstone within the central part 1000 3 Ordovician Shale, the top of the Batesville is typically a topographic flat. Unit The structure contours also illustrate the effects of several broad domes and monoclinal 5 of the quadrangle is based principally on the local roadside exposure of blue-green shale, Mb commonly hosts sinkholes formed by collapse into dissolution cavities in folds, across which the Boone Formation varies as much as 200 ft in elevation. The Mbs 7 Unconformity which is interpreted to be equivalent to the shale-rich middle interval of the St. Peter 1000 4 1410 the underlying Boone Formation. Thickness 40–60 ft Yardelle monocline on the eastern edge of the quadrangle has the greatest relief and is 7 Mf Sandstone described farther to the east and south (McKnight, 1935; Glick and Frezon, 1390 1390 Opl expressed by consistent north to north-northeast dips of as great as 27°. Just to the north, 1400 4 1370 81280 Boone Formation (Upper to Lower Mississippian)—Limestone and cherty 1400 1420 1953). Sparse retrieved from a site (lat 36°3.458' N., long 93°3.826' W.) in this 1280 1290 1420 limestone of main body that grade into the basal St. Joe Limestone a northeast-trending monocline exposes Everton Formation on its upthrown, northwestern 3 1435 Unconformity blue-green shale indicate a Middle Ordovician Mohawkian age and have morphologies that 14 1260 1340 Member. The Boone Formation is a common host of caves and sinkholes. side along Davis Creek. The East Fork monocline continues northward at least 2 mi beyond 1350 are more like those of overlying formations than those in the Everton Formation, thus 1400 5 Middle Total thickness 380–405 ft the north edge of the quadrangle (Hudson, 1998). 3 Mbv Osp ORDOVICIAN supporting a St. Peter identification (J.E. Repetski, written commun., 2003). Limestone Ordovician Mb Main body (Upper to Lower Mississippian, Meramecian to Osagean)— Away from monocline limbs, dips of bedding measured throughout the quadrangle are 1380 from a site (lat 36°3.451' N., long 93°3.771' W.) about 40 ft lower in elevation than this 1340 1350 Unconformity Medium- to thick-bedded, chert-bearing bioclastic limestone. Limestone is typically low and variable in direction. These dispersed attitudes can be attributed in part to shale horizon yielded conodonts that indicate a Middle Ordovician Whiterockian age and 3 light to medium gray on fresh surfaces and generally coarsely crystalline local subsidence caused by karst dissolution within the abundant limestone and dolostone Oe have conodont species that are typical of the Jasper Member (Suhm, 1974) of the upper B with interspersed ossicles. A 1- to 3-ft-thick bed of oolitic limestone rock units. 1360 1280 3 Everton Formation (J.E. Repetski, written commun., 2003). A sample from the Plattin 1390 3 Unconformity is common in upper 10 ft of the Boone Formation. Dense, fine-grained Joints measured within the map area (405 total) are near vertical and distributed in 1390 Mf 5 1050 Limestone mapped in the southeastern corner of the quadrangle (lat 36°0.295' N., long 4 9 beds of limestone are present in upper one-third of unit. Beds are typically several sets (fig. 3B). The dominant sets strike north and northeast. Less prominent joint 1010 4 Mb Lower 93°1.96' W.) yielded latest Whiterockian to late Mohawkian age range conodonts that are 1000 10 Op parallel planar to wavy, but channel fills are locally present in lower part of sets strike west-northwest and northwest. Joint planes within limestone and dolostone 4 Mfw Ordovician typical for the formation and that are consistent with a Middle Ordovician age (J.E. 4 1260 unit. Chert content varies vertically and laterally within the Boone and is formations, such as the Boone Formation, are commonly enlarged due to dissolution. 2 Repetski, written commun., 2003). 10 greatest in the southeastern part of map area. Chert forms lenticular to 9 1250 1325 The Mississippian Boone Formation is the most widespread unit at the surface within 1020 Mbs anastomosing lenses. Chert-rich horizons are generally poorly exposed but ACKNOWLEDGMENTS ၧ the quadrangle. The phosphate-nodule-bearing sandstone at the base of the St. Joe bl produce abundant float of white-weathered chert on hill slopes. Chert in 1300 Mbv 1050 INTRODUCTION Limestone Member is persistent throughout much of northern Arkansas (McKnight, 1935). 12 1320 1015 uppermost part of unit contains prominent molds. Thickness This work was conducted in a cooperative project between the U.S. Geological Survey 3 Mp ၧhg 1010 1040 This sandstone was probably deposited as a transgressive lag during sea-level rise in Late 6 6 Oe 310–375 ft and the U.S. National Park Service. Special thanks go to the many private owners who Mbs 1000 This map summarizes the geology of the Hasty 7.5-minute quadrangle (fig. 1) in the Devonian time (Horner and Craig, 1984). On the eastern side of the quadrangle, the lower 1300 1310 ၧhc 1330 1010 Mbs St. Joe Limestone Member (Lower Mississippian, Osagean to allowed access onto their land during this study. We thank D.N. Mott, C. Bitting, A.K. Ozark Plateaus region of northern Arkansas. Geologically, the area lies on the southern part of the St. Joe Limestone Member directly above the basal sandstone is greenish-gray Kinderhookian)—Thin-bedded, coarse-crystalline bioclastic limestone with Braden, and S.M. Ausbrooks for helpful discussions on the geology, karst features, and Oe 900 flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. fossiliferous shale that yielded conodonts at a site (lat 36°4.057' N., long 93°0.767' W.) that 9 1380 970 ubiquitous 3- to 6-mm-wide crinoid fragments. Limestone is commonly hydrology of the area during the course of the study. Analyses of conodonts from four 1330 Physiographically, the Hasty quadrangle lies within the Springfield Plateau, a topographic indicate a late Kinderhookian age (J.E. Repetski, written commun., 2003). The contact of 13 pink to red on fresh surfaces due to hematite in matrix, but its color and samples by J.E. Repetski of the U.S. Geological Survey helped establish or verify 8 surface generally held up by Mississippian cherty limestone (Purdue and Miser, 1916). The the main body of the Boone Formation with the St. Joe Limestone Member is gradational 7 960 8 hematite concentrations vary with location. Thin beds are typically wavy in stratigraphic assignments. Helpful reviews were provided by J.D. McFarland and S.C. Mb 1050 950 quadrangle also contains isolated mountains (for example, Sulphur Mountain) capped by 980 950 and is based on the change to thin bedding and the generally chert-free lithology of the St. 950 1400 4 form. Chert nodules are uncommon but, where present, are tabular and Lundstrom. 1000 3 Pennsylvanian rocks that are erosional outliers of the higher Boston Mountains plateau to Joe Limestone Member. Near the top of the formation an oolite interval as thick as 3 ft is 1350 reddish. Contact with the overlying main body of the Boone Formation is 10 2 the south. Segments of the Buffalo and Little Buffalo Rivers flow through the southeastern common. Braden and Ausbrooks (2003) also recognized this facies in areas to the south 11 2 4 gradational. Middle to lower part of the St. Joe Limestone Member may REFERENCES CITED part of the map area; these have enhanced bedrock erosion. Exposed bedrock of this 8 9 1440 and correlated this interval with the Short Creek Oolite Member of the Boone Formation, 1420 4 1360 contain shaly limestone interval that is best developed in eastern part of 1010 980 1360 6 region comprises an approximately 1,600-ft-thick sequence of Ordovician, Mississippian, which is present in Missouri and Kansas (McKnight and Fischer, 1970). 1360 Mbv 12 map area. Base of unit is a sequence of phosphate-pebble-bearing tan Braden, A.K., and Ausbrooks, S.M., 2003, Geologic map of the Mt. Judea quadrangle, 6 and Pennsylvanian carbonate and clastic sedimentary rocks (fig. 2) that have been mildly The onset of Morrowan deposition reflects sea-level rise following a terminal 9 St. Joe fault sandstone and overlying greenish-gray shale that is typically 0.5–3 ft thick Newton County, Arkansas: Arkansas Geological Commission Digital Geologic Mp 1490 17 deformed by a series of faults and folds. The Hasty quadrangle includes part of Buffalo Mississippian sea-level drop (Sutherland, 1988). The variable nature of the basal sandstone 18 3 Mbv 8 but thickens to as much as 10 ft where it is exposed along the Davis Creek Quadrangle Map DGM-AR-00590, scale 1:24,000. 24 4 National River, a park encompassing the Buffalo River and adjacent land that is administered interval of the Cane Hill Member of the Hale Formation as well as its content of 1500 8 drainage in northwestern part of sec. 33, T. 17 N., R. 19 W. Thickness Glick, E.E., and Frezon, S.E., 1953, Lithologic character of the St. Peter Sandstone and 3 11 by the National Park Service. conglomerate and wood fragments suggests that this interval contains nonmarine valley-fill Mf 9 1470 12 1040 ၧ 1440 1500 approximately 30–50 ft Everton Formation in the Buffalo River Valley, Newton County, Arkansas: U.S. 8 hc 1500 Mbs The geology of the Hasty quadrangle was first mapped by Purdue and Miser (1916) at fluvial deposits. The study area lies at the northeastern margin of the distribution of thick 1100 1100 Mf 1030 11 13 Of Fernvale Limestone (Upper Ordovician)—Medium- to thick-bedded, coarse- Geological Survey Circular 249, 39 p. 1510 1000 5 1:125,000 scale. The current map confirms many features of this previous study but it also Prairie Grove Member of the Hale Formation (Sutherland, 1988). The Prairie Grove Mbv ၧhg 10 18 1460 750 1040 Mfw 88 crystalline bioclastic limestone. Limestone is light to medium gray on fresh Henbest, L.G., 1953, and lower of Arkansas: American 700 940 identifies new structures and uses a revised stratigraphy. A preliminary map of the 1010 Braden Mountain graben 1060 5 14 2 Mbv 74 1090 980 Member in the study area is represented by indistinct planar-bedded or crossbedded, calcite- 650 700 750 60 39 surfaces and contains abundant 3- to 10-mm-wide cylindrical to barrel- Association of Petroleum Geologists Bulletin, v. 37, p. 1935–1953. 10 1300 1160 9 1470 1490 8 northeastern part of the quadrangle was previously presented by Hudson (1998) at cemented sandstone, 10–20 ft thick, which forms a rounded ledge above the Cane Hill 1030 650 1100 Y 1000 ardelle 950 shaped crinoid ossicles. Distribution is discontinuous and limited to three Horner, G.J., and Craig, W.W., 1984, The Sylamore Sandstone of north-central Arkansas, 1070 1020 14 1:24,000 scale. Member and below the capping cliff-former of the middle sandstone of the Bloyd 1010 1350 ၧhc 1480 thin lenses less than 10 ft thick that are mapped where locally recognized with emphasis on the origin of its phosphate, in McFarland, J.D., III, ed., Contributions 7 1065 1120 1000 Mapping for this study was conducted by field inspection of numerous sites and was 3 1030 1100 3 monocline Formation. Pennsylvanian sandstone and shale of the upper part of the 24 1030 1190 1475 1050 in central and southwestern parts of map area beneath unconformity at to the geology of Arkansas, v. 2: Arkansas Geological Commission, p. 51–85. 6 1340 1460 compiled on a 1:24,000 scale-stable topographic base. Locations and elevations of were originally called Winslow Formation by Purdue and Miser (1916), with the basal 2 Mp 6 base of the St. Joe Limestone Member of the Boone Formation (Mbs) Hudson, M.R., 1998, Geologic map of parts of the Jasper, Hasty, Ponca, Gaither, and Mfw contacts or other sites were determined with the aid of a global positioning satellite receiver Opl Greenland Sandstone Member of the Atoka Formation (Henbest, 1953) representing the 5 8 1095 Oe Plattin Limestone (Middle Ordovician)—Thin- to medium-planar-bedded, Harrison quadrangles in and adjacent to Buffalo National River, northwestern Arkansas: 2 1280 Mf and a hand-held barometric altimeter that was frequently recalibrated at points of known prominent cliff-forming crossbedded sandstone. Zachry (1977), however, concluded that the 830 22 800 1180 3 fine-grained, dense limestone that typically breaks with conchoidal fracture. U.S. Geological Survey Open-File Report 98–116, scale 1:24,000. 7 1090 elevation. Orthophotos and a hill-shade relief image derived from a U.S. Geological Survey cliff-forming sandstone was a time-equivalent unit with the Woolsey Member of the Bloyd 5 1035 1350 1160 1060 Limestone is medium gray on fresh surfaces but weathers to white to light- Hudson, M.R., 2001, Coordinated strike-slip and normal faulting in the southern Ozark 800 1160 10-m digital elevation model were used to help trace ledge-forming units between field Formation farther west and designated it with the informal term “middle Bloyd sandstone.” 9 1110 1050 25 gray tabular blocks. Distribution is restricted to southeastern part of dome of northern Arkansas—Deformation in a late Paleozoic foreland: Geology, v. 14 Mb 1040 Mbv traverses within the Upper Mississippian and Pennsylvanian part of the stratigraphic Unconsolidated sediments are preserved as terrace deposits adjacent to the Buffalo and QTto n Hollow fault Mbs 1050 1360 1070 3 quadrangle where thickness reaches 10 ft 28, p. 511–514. 1130 1410 sequence. Strike and dip of beds were typically measured along stream drainages or at well- Little Buffalo Rivers at several elevations. The relative age of the deposits can be 3 Osp Osp 5 26 ° St. Peter Sandstone (Middle Ordovician)—Fine-grained to very fine grained, Hudson, M.R., Murray, K.E., and Pezzutti, D., 2001, Geologic map of the Jasper 990 750 27 7 exposed ledges to avoid loose rock affected by slope creep. Beds dipping less than 2 are determined from their height above the river, but there are no constraints on their absolute 800 Stringtow 960 1050 7 tan sandstone and interbedded blue-green siltstone and shale. Sandstone is quadrangle, Newton and Boone Counties, Arkansas: U.S. Geological Survey 1200 13 5 shown as horizontal. Structure contours constructed on the base of the Boone Formation age. The youngest deposits are almost certainly Quaternary in age, but the oldest deposits, Qty Of 1020 1200 6 calcite-cemented quartz arenite with rounded grains; commonly strongly Miscellaneous Field Studies Map MF–2356, scale 1:24,000. 2 800 15 3 were hand drawn based on elevations of control points on both lower and upper contacts of Osp 3 12 15 4 which are 140–180 ft above the river, could potentially be as old as Tertiary (>1.8 Ma). 1000 850 bioturbated. In central part of map area, unit consists mainly of McFarland, J.D., III, 1988, The Paleozoic rocks of the Ponca region, Buffalo National River, 950 800 1090 700 the Boone Formation as well as other limiting information on their maximum or minimum 1005 900 750 2 7 interbedded blue-green shale, siltstone, and sandstone that are locally Arkansas, in Hayward, O.T., ed., Centennial Field Trip Guide, v. 4: Geological Society 1205 ၧ 12 elevations. STRUCTURAL GEOLOGY 780 hc exposed along roadside. Thickness varies from 0 to 40 ft of America, p. 207–210. Mf 3 13 1140 Oe Everton Formation (Middle Ordovician)—Interbedded sandstone, dolostone, McKnight, E.T., 1935, Zinc and lead deposits of northern Arkansas: U.S. Geological 8 1160 1130 880 10 9 750 DESCRIPTION OF MAP UNITS Rocks within the map area were mildly deformed by a system of faults and folds. 4 Mp and limestone sequence. Sandstone is quartz arenite with well-sorted, well- Survey Bulletin 853, 311 p. 2 4 Mfw Structure contours on the base of the Boone Formation illustrate the location of structures 7 6 rounded, and fine to medium quartz grains. Sandstone is present in McKnight, E.T., and Fischer, R.P., 1970, Geology and ore deposits of the Picher field, 950 980 1320 1000 Qty Younger terrace and active-channel alluvial deposits (Quaternary)— and their vertical offset. The structure contours conform to elevations at 263 control points 5 1355 8 medium to thick planar beds and is light tan to white and cemented by Oklahoma and Kansas: U.S. Geological Survey Professional Paper 588, 165 p. 790 Mb 41320 Unconsolidated sand and gravel of Buffalo River. Terrace deposits are located at both lower and upper contacts of the Boone Formation, as well as other 900 3 Mbv Oe dolomite and (or) calcite. Poorly cemented sandstone breaks with sugary Purdue, A.H., and Miser, H.D., 1916, Descriptions of the Eureka Springs and Harrison 850 7 9 1010 Mbs principally composed of light-brown, fine sand; smooth upper surfaces are information limiting maximum or minimum elevations. A 390-ft thickness for the Boone 820 4 4 15 texture. Upper part of the Everton Formation contains 3- to 20-ft-thick, quadrangles: U.S. Geological Survey Atlas, Folio 202, scale 1:125,000. 920 935 16 5 about 20 ft above base-flow level of river. Active-channel gravel deposits 8 940 1370 Formation (including the St. Joe Limestone Member) was used to project the elevation of Oe 6 2 light- to dark-gray limestone and dolostone beds that are commonly Suhm, R.A., 1974, Stratigraphy of Everton Formation (early Medial Ordovician), northern 845 are composed of subangular to rounded Paleozoic rock clasts of mixed the basal contact from points on the upper contact, based on the average of five traverses 8 interbedded with sandstone. Middle part is a sandstone interval, the Arkansas: American Association of Petroleum Geologists Bulletin, v. 58, p. 685–707. 4 lithology along drainages, and they are interspersed with bedrock across stratigraphic sections near the Buffalo River (Hudson, 1998) whose thicknesses range 850 3 78 6 Newton Sandstone Member of the Everton of McKnight (1935). Lower Sutherland, P.K., 1988, Late Mississippian and Pennsylvanian depositional history in the 860 Mbs 4 exposures (not mapped). As thick as 20 ft from 380 to 405 ft. The vertical offset of structures can be estimated from the elevation 905 10 3 part contains 3- to 6-ft-thick limestone and dolostone beds interbedded Arkoma basin area, Oklahoma and Arkansas: Geological Society of America Bulletin, 910 Qtm Medial terrace and alluvial deposits (Quaternary)—Unconsolidated sand difference of formation contacts across the structures, but lateral offset is difficult to measure B' with sandstone. Carbonate beds in both upper and lower parts of unit are v. 100, p. 1787–1802. 7 30 22 deposits adjacent to Buffalo River. Deposits are poorly exposed and are 2 1000 due to the lack of appropriate markers. Kinematic data indicating fault slip directions are 860 4 29 typically finely crystalline and sparsely fossiliferous, and commonly display Sylvester, A.G., 1988, Strike-slip faults: Geological Society of America Bulletin, v. 100, p. 5 2 905 7 principally brown-weathered, fine sand as high as 40 ft above base-flow sparse within the quadrangle, but elsewhere in the Buffalo River region (Hudson, 2001) Mb 7 910 950 crinkly laminations. Exposed thickness along Little Buffalo River as much 1666–1703. 5 7 level of river. Includes deposits within abandoned channel of Buffalo River kinematic data indicate that east- to east-southeast-striking faults typically have normal slip Qty 850 as 200 ft, but base not exposed Zachry, D.L., 1977, Stratigraphy of middle and upper Bloyd strata (Pennsylvanian, 4 8 930 4 east of Lost Hill. Thickness uncertain but probably as much as 20 ft whereas northeast-striking faults have oblique slip, with both right-lateral and normal 890 900 Op Powell Dolomite (Lower Ordovician)—Shown in cross sections only. Morrowan), northwestern Arkansas, in Sutherland, P.K., and Manger, W.L., eds., 850 855 950 QTto Older terrace and alluvial deposits (Quaternary and Tertiary (?))— components of offset. 970 Argillaceous brownish-gray dolostone. Regionally, thickness varies from Upper Chesterian–Morrowan stratigraphy and the Mississippian-Pennsylvanian 3 950 Unconsolidated gravel and sand deposits adjacent to Buffalo River. The dominant structural feature of the Hasty quadrangle is a graben system that 840 Of 40 to 200 ft (McFarland, 1988) boundary in northeastern Oklahoma and northwestern Arkansas: Oklahoma Osp Deposits are poorly exposed and are principally a lag of brown-weathered, extends from east to west across the center of the quadrangle. Purdue and Miser (1916) 920 Geological Survey Guidebook 18, p. 61–66. 4 880 850 14 subrounded to rounded Paleozoic rock clasts of mixed lithology in a sandy 870 4 Mb QTto 2 matrix 140–180 ft above base-flow level of river. Thickness uncertain but 850 965 4 probably no more than 5 ft Qtm 900 890 2 Ql Landslide (Quaternary)—Large slide blocks of limestone, sandstone, and shale 950 Mbs 4 derived from the Pitkin Limestone (Mp) and the Wedington Sandstone Oe 900 Member (Mfw) and main body of the Fayetteville Shale (Mf); generally back 1295 1000 tilted into hillside on north side of Sulphur Mountain. Blocks moved over

4 970 middle and lower parts of the Fayetteville Shale 890 ° Oe Bloyd Formation (Lower Pennsylvanian, Morrowan)—Interbedded sequence 93°22'30" 93°15' 93°7'30" 93 925 980 36°15' 990 Qtm of sandstone, siltstone, shale, and thin limestone beds separated into lower OSAGE NE GAITHER HARRISON Of 900 QUAD. QUAD. QUAD. METERS

and upper intervals. As much as 300 ft thick SYSTEM 890 920 Harrison PROVINCIAL SERIES 960 1320 ၧ QTto Oe bu Upper part—Prominent crossbedded sandstone that forms cliffs as tall as 60 500 FEET Osp ft capping Sulphur, Boat, and Pinnacle Mountains. Sandstone is white to 970 1600 900 light-brown, fine- to medium-grained quartz arenite and is commonly a 902 8 65 Mbs composite of several 1- to 3-ft-thick tabular and trough crossbed sets. 43 Sandstone has a sharp erosional base and contains concentrations of white 880 quartz pebbles and, locally, casts and molds of wood fragments. Rocks of 1315 the upper Bloyd Formation were originally assigned to the Winslow Upper part Mb 840 4 7 10 Mb 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 18 1400

Carroll Co. 880 Bloyd Formation farther west and designated it the “middle Bloyd FORMATION 890 940 Lower part 920 sandstone.” Maximum preserved thickness 160 ft 36°7'30"

ၧ Morrowan 8 bl Lower part—Sequence of predominantly dark-gray to black shale and Boone Co. 400 1240 Prairie Grove Member Oe 985 siltstone with thin beds of sandstone and limestone; forms moderate to Newton Co. 960

steep slopes, but is poorly exposed. Fine-grained, planar-bedded, olive- PENNSYLVANIAN (part) Qty 3 960 2 Cane Hill Member 2 brown sandstone beds, 5–10 ft thick, are locally exposed as ledges. Coarse 880 1240 HASTY 1200 HALE 7 bioclastic limestone is reddish gray and weathers dark brown but is poorly Mbs 5 950 exposed and mostly observed as loose blocks in lower part of sequence. QUADRANGLE FORMATION Mbv National PITKIN LIMESTONE 860 Thickness 90–120 ft Buffalo 940 940 Hale Formation (Lower Pennsylvanian, Morrowan)—Interbedded sequence Wedington Sandstone Member 950 of sandstone, siltstone, shale, and thin limestone. Thickness 100–180 ft River Mbs 950 Buffalo ၧhg Prairie Grove Member—Brown to reddish-brown, fine- to medium-grained, River 05 km 950 950 Ponca 7 QTto 960 thick-bedded, calcite-cemented sandstone. Locally contains quartz pebbles 1000 895 300 FAYETTEVILLE in its base. Beds are planar or crossbedded, and crossbeds may have bi- JASPER 930 43 PONCA Jasper SHALE 920 directional dips. Weathered sandstone forms rounded surfaces. Sandstone QUAD. QUAD. 900 Osp 36°00'

forms steep slopes but is commonly covered by slope debris from overlying Chesterian 930 Mb units. Thickness 10–20 ft Mbs ၧhc Cane Hill Member—Interbedded sequence of shale, siltstone, and 94° 92° 90° sandstone. Upper part is poorly exposed and composed of dark-gray shale 3 930 960 and thin-bedded siltstone that form gentle to moderately steep slopes. St. Francois 800 BATESVILLE SANDSTONE 940 940 Mountains 950 Oe 930 Lower part is a 10- to 20-ft-thick sandstone interval of reddish-brown, Ozark Dome QTto 890 960 Opl medium- to thick-bedded, very fine grained to medium-grained sandstone EXPLANATION 920 Qty Mbs 14 920 with trough crossbeds. Lower sandstone changes upward to olive-brown, Kansas Salem Plateau 895 Opl 37° 910 7 very fine grained to fine-grained, thin-bedded sandstone with ripple cross- Oklahoma 940 910 Springfield 200 lamination or parallel lamination. Basal sandstone locally contains casts of Missouri Crossbedded sandstone 940 960 Plateau BOONE 880 wood fragments and conglomerate lenses with quartz pebbles and angular MISSISSIPPIAN 9205 600 FORMATION Meramecian- 4 Osagean 957 to subrounded clasts of shale, siltstone, and sandstone. Unit unconfomably A' 3 3 overlies the Pitkin Limestone. Thickness varies from 80 ft to as much as Boston Mountains Sandstone Base from U.S. Geological Survey, 1967 6.5° SCALE 1:24 000 Geology mapped by M.R. Hudson intermittently from 260 ft at Braden Mountain Projection and 10,000-foot grid ticks: Arkansas 1 1/ 2 0 1 MILE 1996 to 2003 Mp Pitkin Limestone (Upper Mississippian, Chesterian)—Generally medium- to 3 Arkoma Basin coodinate system, north zone Manuscript approved for publication August 6, 2004 dark-gray, fetid limestone. Limestone texture varies from micritic to coarse Tennessee ARKANSAS ° 1000-meter Universal Transverse Mercator grid, 35 1 .5 0 1 KILOMETER 2 grained and is locally oolitic. Limestone beds may contain abundant Mississippi zone 15 ETIC NORTH crinoids, brachipods, corals, and bryzoan Archimedes. Basal contact with 400 St. Joe Limestone Member Shale, siltstone

GN TRUE NORTH 7 FERNVALE LIMESTONE 1927 North American Datum CONTOUR INTERVAL 20 FEET the Fayetteville Shale is conformable, although rarely exposed. The Pitkin Ouachita Mountains MA 2 PLATTIN LIMESTONE APPROXIMATE MEAN NATIONAL GEODETIC VERTICAL DATUM OF 1929 generally forms a prominent ledge or cliff. Thickness 40–100 ft Osagean- DECLINATION, 1967 QUADRANGLE LOCATION Mississippi Embayment 100 ST. PETER SANDSTONE

Cretaceous Kinderhookian rocks 3 Limestone Texas

Sulphur Arkansas 200 EVERTON Mountain 33° A A' FORMATION Dolomite ၧbu FEET FEET Figure 1. Location of study area within northern Arkansas, adjacent to the western part ၧbl ၧ Braden 2000 ၧ hg 2000 of Buffalo National River. Lower regional map illustrates geological and selected

hc St. Joe fault Mp Mountain physiographic provinces of Arkansas and adjacent areas. ORDOVICIAN Chert ၧhc Mfw Creek fault POWELL DOLOMITE Mf Upper Flatrock Mp 1500 1500 Mbv Mbv 00 Mfw Mb Figure 2. Stratigraphic column for Paleozoic rocks of the map area. Provincial series are from Purdue Mb Mf Mb Mb Mb Mbs Mbs and Miser (1916) and McFarland (1988).

Mbs River Buffalo 1000 1000 Mbv Mbs Mb Qty Oe Oe Oe Graben system N N 500 Mbs 500 Op Op AT Oe Op

Op

VERTICAL EXAGGERATION X 2

B B' Figure 3. Structural data for the Hasty quadrangle. A, Faults associated FEET FEET with the east-west-trending graben system. Great circles and dots are 2000 2000 lower hemisphere projections of fault planes and their slip lines, 6 % respectively. Arrows show movement sense of hanging wall. Thick

ardelle lines designate main fault planes of graben system and thin lines Y St. Joe fault 1500 monocline 1500 designate associated minor fault planes. B, Rose diagram of strike Mf Mb Mbv Mb frequency of joints recorded within the map area. Mbs Mb Mbs Mbs 1000 1000 Mb Osp Oe GEOLOGIC MAP OF THE HASTY QUADRANGLE, BOONE AND NEWTON COUNTIES, ARKANSAS 500 Oe 500 Op Op By N = 405 Any use of trade names is for descriptive purposes only and does not imply endorsement by the U.S. Government Mark R. Hudson and Kyle E. Murray CONVERSION FACTORS VERTICAL EXAGGERATION X 2 This map was produced on request, directly from 2004 ABFaults and striations Joints Multiply By To obtain digital files, on an electronic plotter inches (in.) 2.54 centimeters (cm) For sale by U.S. Geological Survey Information Services feet (ft) 0.3048 meters (m) Box 25286, Federal Center, Denver, CO 80225 miles (mi) 1.609 kilometers (km) 1-888-ASK-USGS ArcInfo coverages and a PDF for this map are available at http://pubs.usgs.gov