GEOLOGICAL SURVEY CIRCULAR 249

LITHOLOGIC CHARACTER OF THE ST. PETER AND THE EVERTON FORMATION IN THE BUFFALO RIVER VALLEY, NEWTON COUNTY, ARKANSAS UNITED STATES DEPARTMENT OF THE INTERIOR Douglas McKay, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director

GEOLOGICAL SURVEY CIRCULAR 249

LITHOLOGIC CHARACTER OF THE ST. PETER SANDSTONE AND THE EVERTON FORMATION IN THE BUFFALO RIVER VALLEY NEWTON COUNTY, ARKANSAS

By Ernest E. Glick and Sherwood E. Prezon

Washington, D. C., 1953

Free on application to the Geological Survey, Washington 25, D. C. CONTENTS

Page Page Introduction ...... 1 Detailed sections of the St. Peter sandstone Everton formation ...... 4 and Everton formation along the Beds below the Newton sandstone Buffalo River, Newton County, member...... 4 Ark. Continued Newton sandstone member ...... 4 Section C ...... 11 Beds between the Newton sandstone Section D ...... 14 and Jasper members...... 6 Section E ...... 16 Jasper member...... 6 Section F ...... 18 St. Peter sandstone ...... 6 Section G ...... 21 Detailed sections of the St. Peter sandstone Section H ...... 25 and Everton formation along the Buffalo Section I ...... 32 River, Newton County, Ark...... 7 Section J ...... 33 Section A...... 7 Literature cited...... 39 Section B ...... 9

ILLUSTRATIONS Page Figure 1. Map showing location of sections of the St. Peter sandstone and Everton formation measured along the Buffalo River, Newton County, Ark...... 2 2. Cross section showing the lithologic character of the St. Peter sandstone and Everton formation along the Buffalo River, Newton County ...... 3

iii UTHOLOGIC CHARACTER OF THE ST. PETER SANDSTONE AND THE EVERTON FORMATION IN THE BUFFALO RIVER VALLEY NEWTON COUNTY, ARKANSAS

By Ernest E. Click and Sherwood E. Frezon

INTRODUCTION Fine-grained sandstone, 0.125 to 0. 25 mm in diameter. Since 1949, the U. S. Geological Survey, with Medium-grained sandstone, 0. 25 the informal cooperation of the Division of Geology, to 0. 50 mm in diameter. Arkansas Resources and Development Commission, Coarse-grained sandstone, 0. 50 has been engaged in stratigraphic investigations in to I. 00 mm in diameter. northern Arkansas to aid in the search for oil and gas Very coarse grained sandstone, in the Arkansas Valley. These investigations include 1. 00 to 2. 00 mm in diameter. surface and subsurface studies, some of which have been completed and published (Lantz, 1950; Maher Because the sand in the carbonate rocks and Lantz, 1952, 1953). i Work currently in progress and the is composed dominantly of includes the preparation of subsurface cross sections frosted subrounded to rounded quartz grains, these of the pre-Atoka rocks in the Arkansas valley, and characteristics are not included in the detailed areal mapping in the Mount Judea and Snowball descriptions. The approximate size of the sand quadrangles of Searcy and Newton Counties. This grains is given for the sandstones but not for the report presents and discusses the detailed strati- carbonate rocks. In general, both fine- and medium- graphic sections used in correlating and mapping sized grains are present in the sandy carbonate rocks. the St. Peter sandstone and Everton formation in the Mount Judea and Snowball quadrangles,. The bedding is described as follows: The detailed descriptions of surface sections in Fissile, less than 1/16 inch thick. this report are based on rock samples collected in Platy, 1/16 to 1/2 inch thick. the Buffalo River valley in Newton County, Ark., at Very thin bedded, 1/2 to 2 inches 'thick. the localities shown in figure 1. The sections were Thin-bedded, 2 to 4 inches thick. measured in the field by tape and hand level; all units Medium-bedded, 4 to 12 inches thick. were measured perpendicular to the bedding. Field Thick-bedded, 12,to 36 inches thick. descriptions were made with special emphasis on Massive, more than 36 inches thick. bedding and weathering, and representative samples were taken of each lithologic unit for laboratory The term "cryptozoon structure" refers to any examination and lithologic description. The samples structure which suggests that a unit is in part algal were crushed, washed, and examined in the office in origin. This includes a distinctive type of wavy with a binocular microscope. -Field and laboratory banding in and dolomite beds as well as data were then combined into the detailed sections preserved colonies of calcareous algae in limestone included in this report. beds. In the past these algal colonies have been The terminology used in the descriptions of the sam­ referred to Cryptozoon sp. ples is essentially that used by most geologists in the mid- continent region, making microscopic examinations of The National Research Council rock-color chart well samples. A limestone or dolomite is called "crystalline" was used for color names in the descriptions. Colors if the texture is rough and crystal faces can be seen, obviously due to weathering were not described. "granular" if the texture is rough and crystal faces can­ not be seen, and "dense "if the texture is smooth. A Colored log strips on the scale of 10 feet to the carbonate rock that leaves a large residue of silt after inch were prepared from the detailed lithologic digestion in acid is called "silty"; one containing indeter­ descriptions of this report. A detailed cross section minate, round or ovate, particles about the size of oolites was constructed from information on these log strips is termed "oolitoid. " Sandstone with siliceous cement and was generalized in the form of figure 2. This is called "quartzitic " if it breaks across the sand grains. figure shows the lithologic character of the St. Peter The terms given below are used in accordance with the sandstone and members of the Everton formation in Wentworth Grade Scale: ten sections along the Buffalo River designated A to_Jin figure 1. The datum used in alining these Silt, 0.0039 to 0.062 mm in diameter. sections is the top of the basal sandstone Very fine grained sandstone, 0.062 to 0.125 mm of the Jasper member of the Everton formation in diameter. except in section A, where this unit is absent. Section A is alined on the top of the Newton sandstone 1 See page 39 for literature cited. member. R.2IW. R.20W. 93" OO1 R.I9W. R.I8W.

Line of cross section shown in figure 2

R.2IW. R.20W. 93-001 R.|9 W. R.I8W.

Figure 1. Map showing location of sections of the St. Peter sandstone and Everton formation measured along the Buffalo River, Newton County, Ark. FERNVALE LIMESTONE ()

Limestone and thin sandstone beds

Sandstone and thin limestone beds

Member boundary

Facies boundary

50- Datum is top of basal sandstone of the Josper member of the Everton formation in sections B to J. Section A is alined on the top of the Newton sandstone member of the Everton for­ 3 Miles mation . Letters above sections refer to loca­ tions in figure I

Figure 2. Cross section showing the lithologic character of the St. Peter sandstone and Everton formation along the Buffalo River, Newton County, Ark. The authors wish to thank H. D. Miser, of the member of the Boone formation along the line of these U. S. Geological Survey, for giving generously of sections. The -St. Peter sandstone overlies the his time and experience in discussing some of the Jasper member of the Everton formation in sections D problems encountered, and N. F. Williams, through J. At each of these localities the St. Peter director, Division of Geology, Arkansas Resources rests upon an irregular wavy surface. This irregularity and Development Commission, who provided base is most striking in section J where 4 feet of relief is maps and extended many courtesies. Section E of this present on the top of the limestone beds in a lateral report is a part of a previously published section at distance of 25 feet. The basal sandstone member of Carver, Ark. (Maher and Lantz, 1952, p. 10-12). the Boone formation overlies the Everton formation in sections A, B, and C. It rests on beds older than Jasper in section A , on a nearly complete thickness EVERTON FORMATION (MIDDLE ORDOVICIAN) of Jasper in section B , and on a thin remnant of Jasper in section C.~ These irregularities are A Middle Ordovician sequence of limestone, attributable mostly to truncation of local structures sandstone, and dolomite beds,about 405 feet thick, before deposition of the Boone formation. separates the Powell dolomite (Lower Ordovician) and the St. Peter sandstone (Middle Ordovician) near Mount Hersey in the Yellville quadrangle (section _J, Beds below the Newton sandstone member figs. 1 and 2).. McKnight (1935,. pi. 3) mapped this sequence as the Everton formation and noted that the Beds of the Everton formation below the upper limestone beds are lithologically identical with Newton sandstone member are partially exposed in the Jasper limestone mapped in the adjacent Harrison sections A , C , F , G, H, and J. The exposure of quadrangle by Purdue and Miser (1916, p. 8) as a separate this sequence in section J is 245~feet thick. These formation. He also suggested that detailed stratigraphic beds exhibit a limy facies in section A which grades work in the Buffalo River valley south of the Harrison eastward into a dolomitic facies in section G to J . and Yellville quadrangles would show that the (See fig. 2.) The limy facies consists of light olive- Jasper limestone should be considered as a member gray oolitic ostracodal dense limestone interbedded of the'Everton. The writers, who have assisted in the with limy sandstone; the dolomitic facies is composed mapping of the Buffalo River valley immediately south of brownish-gray finely to medium-crystalline dolomite of the Harrison and Yellville quadrangles (fig. 1), find interbedded with dolomitic sandstone. The limy facies that the Jasper limestone can be traced into the upper locally contains preserved algal colonies; both facies part of the Everton formation as suggested by locally exhibit wavy banded beds which are probably McKnight. They also believe that, although the algal in origin. A loosely coiled cephalopod(?) and Jasper limestone is a mappable unit in the what seem to be molds of small pelecypod valves Harrison quadrangle, it is not a mappable unit farther were found in the lower part of the limy facies of east because the base becomes indistinct owing to section G. In general fossils are poorly preserved gradation into underlying beds, and the upper in the dolomitic facies. The Kings River sandstone that typify the unit at Jasper grade laterally into member and the Sneeds limestone lentil, which compose dolomite beds (fig. 2). Therefore the Jasper limestone the lower part of the Everton formation in the is treated in £his report as the Jasper member of the Harrison quadrangle (Purdue and-Miser, 1916, p. 5), Everton formation. The'chart on page 5 shows the are not identifiable in section J, a nearly complete classification used in this report and the changes in exposure of this sequence. names and correlations that have been made in the last four decades. Newton sandstone member The Everton formation is widely distributed over' northern Arkansas and is well exposed in the cliffs The Newton sandstone member of the Everton along the Buffalo River in northern Newton and formation was named by McKnight (1935, p. 39) for ^Searcy Counties. The name is taken from'the town its prominence in northern Newton County, Ark. of Everton in the Yellville quadrangle (Ulrich, 1911, Previously this sandstone had been mapped as the pi. 27), where only part of the formation is exposed. St. Peter sandstone in the Eureka Springs and The most complete exposure in the area of this Harrison quadrangles by Purdue and Miser (1916, p. 7). investigation is at the locality of section J. (See fig. 1). According to Purdue and Miser, the sandstone thins There the formation is about 405 feet thick and is eastward from 15O feet in northwestern Newton County composed of four lithologic units. In ascending order to 15 feet in northeastern Newton County. This eastward these units are (1) a sequence of dolomite and sandstone, thinning is also present in the Buffalo River valley 245 feet exposed, base covered, (2) the Newton Sandstone ( fig. 2) where the Newton sandstone member thins member, 8 feet thick, (3) a sequence of dolomite and from about 65 feet in section A to about 8 feet in sandstone, 90 feet thick, and (4) the Jasper member, section J . Much of this thinning seems to be the 55 feet thick. The upper part of the Powell dolomite result oFthe basal beds of the sandstone grading and the lower 10 feet or less of the Everton formation laterally into limestone and dolomite beds. are covered at this locality; the contact of the two formations, which according to McKnight (1935, p. 40) The massive Newton sandstone member forms is unconformable, is about 55 feet above river level. a prominent cliff along the Buffalo River in central The base of the Everton formation is below river level Newton County; however, in the eastern half of the at the localities of the other sections described in area of this study, it is thjn and hardly distinguishable this report. from other sandstones of the Everton formation. It is composed primarily of rounded and frosted fine The Everton formation is unconformably overlain to medium sand grains bound by a small amount of by the St. Peter sandstone and the basal sandstone limy cement. The only fossiliferous bed found in the Names and equivalents of Middle and Lower Ordovician rocks in Newton County, Ark.

Present report McKnight, E. T. , 1935, Purdue, A. H. , and Miser, (Circ. 249) Zinc and lead deposits H. D. , 1916, U. S. Geol. of northern Arkansas: Survey Geol. Atlas, U. S. Geol. Survey Eureka Springs-Harrison Bull. 853. folio (no. 202).

St. Peter sandstone. St. Peter sandstone. (Generally absent).1

Jasper member. Jasper limestone.2 Jasper limestone.

Joachim limestone.3 Dolomite and sandstone.

o Newton sandstone Newton sandstone St. Peter sandstone.3 member. member. 1 "^& c -I-Ho 0 ±j t: g 0) ^ w o 3 w formation Limestone, dolomite, and sandstone. Kings River sandstone member. S 2

Sneeds limestone lentil.

Powell dolomite. Powell dolomite. Powell limestone.

1 Section D of the present report indicates that a thin remnant 3 McKnight, (1935, table facing p. 16) states: "The so-called of true St. Peter sandstone is present locally in theHarrison quadrangle. 'Joachim limestone' and so-called 'St. Peter sandstone' of the 2 McKnight (1935, table racing p. 16) states: "Future work may Eureka Springs and Harris on quadrangles are equivalent to the upper show that the Jasper limestone should be classed as s part of the portion of the Everton formation of the Yellville quadrangle." Everton formation." member is a thin ostracodal limestone in the middle the Ozark region. In mapping the Eureka Springs of the unit in section A . and Harrison quadrangles, Purdue and Miser (1916, p. 7) applied the name to a massive sandstone which was thought to be correlative Beds between the Newton sandstone with the St. Peter of the Yellville district and Jasper members to the east. Croneis (1930) and Giles (1930) followed the correlations of Purdue and Miser A sequence of dolomite, sandy dolomite, and in this area. Later McKnight (1935, p. 39) dolomitic sandstone beds, about 90 feet thick, con­ showed that the massive sandstone mapped by formably overlies the Newton sandstone member. Purdue and Miser in the Eureka Springs and This dolomitic sequence becomes increasingly Harrison quadrangles is not correlative with sandy toward the top and grades, into the limy basal the St. Peter of the Yellville quadrangle but sandstone of the Jasper member. The contact is a member (Newton sandstone) of the with the overlying Jasper member, which is drawn Everton formation. (See chart.) arbitrarily at the top of the dolomitic beds, does not follow bedding planes. The character of the entire The St. Peter sandstone is exposed in unit changes little within the area although individual the valley of the Buffalo River in northeastern beds do not remain distinctive when traced laterally. Newton and northern Searcy Counties, Ark. A few poorly preserved ostracods were found. It is present in sections D to J of this report, ranging in thickness from a fraction of a foot to 73 feet (section H). The St. Peter sand­ Jasper member stone appears to rest unconformably on the Everton formation. No angular discordance The Jasper member is composed of two major between the formations was noted, but the lithologic units, a basal limy sandstone unit and an contact is undulating the lowermost sand beds overlying sandy limestone or sandy dolomite unit. of the St. Peter dip into the depressions The contact between the two units is so clearly de­ and lap over the higher parts of the uneven fined by a sharp lithologic cha'nge from a sandstone-to surface of the Everton. The St. Peter is a massive limestone and dolomite bed that this unconformably overlain by the . horizon has been used as a datum for the cross section Where the 'Plattin limestone has been cut out, of figure 2. the Boone formation overlies the St. Peter with evident angular . This angular In section B, the basal sandstone of the Jasper unconformity is best seen in the area of member is 14 feet thick and composed entirely of section D. friable limy sandstone beds; in section D, the basal sandstone of the Jasper is 35 feet thick and includes The St. Peter sandstone is so poorly five thin ostracodal limestone beds. Eastward from exposed in the Buffalo River valley that no section D , the lower part of the basal sandstone of complete section could be obtained. The the Jasper grades into the underlying dolomitic beds. maximum thickness of the St. Peter in the The basal sandstone is represented in section J by area investigated is 73 feet in section H, only 11 feet of limy sandstone and thin limestone beds. but a considerable part of this thickness could not be sampled or described. Purdue and Miser (1916, p. 8) described the upper unit of the Jasper as a dense limestone "inter- bedded with a subordinate though considerable amount The base of the formation in section H is of sandstone." Much of the limestone is oolitic a fine- to medium-grained sandstone bed, 6 feet and some of it is sandy. Eastward from the 9 inches thick, containing thin quartzitic layers. type area, this limy facies (sections B and D) The sand grains are partly rounded and frosted grades into a dolomitic facies (sections E, ~" and partly angular as a result of secondary F , G, H, and J_) and back into a limy facies quartz growth. Topographically, this basal (section J). Because individual sandstone beds unit forms a low bench in all the sections of the Jasper can be correlated throughout this from D to £ . Above the basal sandstone of area, it is evident that "the limy and the dolomitic section H lies a covered interval, 58 feet facies are parts of the same unit. thick, which has its counterpart in sections E, F , G , and J . Scattered exposures in sections E , The Jasper member is the most fossiliferous F , and G Indicate that the interval consists part of the Everton formation. Ostracods are of a sequence of soft dolomitic or limy silty sand­ abundant in most of the limestone beds, and stone and silty sandy dolomite beds. Ostracod cephalopoda, gastropods, pelecypods, trilobites, molds were found in this unit in sections E worm borings, and fossil algae have been found and F. A bed of sandstone about 8 feet tEick in certain localities. Fossils in the dolomite is present above the covered interval in beds of the Jasper are generally few and section H, but apparently it is not present poorly preserved. in any of the other sections. This bed is similar in lithology and outcrop to the lower sandstone of the formation. The presence of ST. PETER SANDSTONE upper and lower sandstone units separated by a thick covered interval suggests that the three lithologic Adams and Ulrich (1905, p. 3) introduced the units in the St. Peter noted by McKnight (1935, name St. Peter sandstone, first used by Owen (1847, p. 43) in the Yellville quadrangle may be present p. 169) in Minnesota, into the geologic literature of in section H. DETAILED SECTIONS OF THE ST. PETER SANDSTONE AND EVERTON FORMATION ALONG THE BUFFALO RIVER, NEWTON COUNTY, ARK. A. Section of the Everton formation, 200 yards Ft in_ upstream from the north end of the Buffalo River Ordovician rocks Continued bridge on State Route 7 in the NWiNEi sec. 7, Everton formation Continued T. 16 N., R., 20 W., Newton County, Ark. Base Dolomite, medium-bedded, of section at river level. light brownish-gray, finely crystalline; contains small () rocks: dolomite pebbles in upper Boone formation: 2 inches,and scattered sand St. Joe limestone member. grains throughout...... 2 2 Basal sandstone member. Sandstone, medium-bedded, Ft in_ light brownish-gray, very Ordovician rocks: dolomitic, very fine to Everton formation: medium-grained...... 1 8 ' Dolomite, medium-bedded, Dolomite, medium-bedded, brownish-gray, sandy, very dark-gray, very finely finely granular; granular; contains scattered contains some dolomite sand grains and a few white stringers without sand; coarse dolomite ostracods in the lower crystals...... 3 0 3 inches...... 5 0 Dolomite, medium-bedded, Sandstone, medium-bedded, light olive-gray to dark- brownish-gray, dolomitic gray, slightly limy, very fine- to medium-grained; finely granular; contains thin contains thin stringers of yellowish-gray sandstone dikes dolomite ...... 5 0 (mud-crack fillings?) in the Sandstone, medium-bedded, upper beds...... 5 0 brownish-gray, dolomitic, Dolomite, medium-bedded, slightly limy, fine- to medium- medium light-gray, very grained; contains white coarse finely granular; contains calcite crystals ...... 3 5 scattered sand grains ...... 1 0 Dolomite, medium - Sandstone, medium-bedded, bedded, light brownish- yellowish-gray, limy, gray to brownish-gray, medium-grained; contains sandy, very finely stringers of light olive-gray granular ...... 2 4 dolomitic sandstone...... 1 0 Sandstone, medium- Sandstone, medium-bedded, bedded, yellowish-gray, white to yellowish-gray, dolomitic, fine- to slightly limy, medium- medium-grained; grains grained; grains exhibit second­ exhibit secondary growth; ary growth ...... 3 5 contains stringers of Dolomite, thin- to medium- brownish-gray dolomite bedded, dark-gray, very 1 to 2 inches finely granular; contains thick...... 5 10 scattered sand grains...... 10 Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, finely yellowish-gray, limy, fine- crystalline ...... 6 to medium-grained ...... 5 Sandstone, thin-bedded, Dolomite, medium-bedded, yellowish-gray, slightly light olive-gray, finely limy, poorly sorted, crystalline; contains some fine- to coarse­ white coarse calcite grained ...... 6 crystals ...... 3 6 Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, sandy, finely yellowish-gray to light crystalline; ostracods ...... 3 2 brownish-gray, very dolo­ Dolomite, medium-bedded, mitic, fine- to medium- yellowish-gray, sandy, grained; contains white slightly limy, finely limy sandstone stringers .... 1 6 crystalline...... 2 7 Sandstone, medium-bedded, Dolomite, medium-bedded, light brownish-gray, very light brownish-gray to olive- dolomitic, fine- to medium- gray, slightly limy, dense; grained ...... 2 7 contains scattered sand Dolomite, medium-bedded, grains...... 8 light olive-gray, finely crystal­ Dolomite, medium-bedded, line ...... 6 light brownish-gray, sandy, Sandstone, thin-bedded, light slightly limy, very finely brownish-gray, very dolo­ granular to finely mitic, fine-to medium- crystalline ...... 10 grained ...... 3 Ft in_ £t, i2. Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Newton sandstone member: Newton sandstone member Con. Sandstone, thin- to medium - Sandstone, thin- to bedded, yellowish-gray, medium-bedded, slightly limy, fine- to yellowish-gray to medium-grained...... 3 10 white, limy, fine- to Sandstone, crossbedded, medium-grained; grains thin- to mediumrbedded, exhibit secondary yellowish-gray, fine- to growth ...... 5 0 medium-grained ...... 5 0 (Base of Newton sandstone member) Sandstone, crossbedded, Limestone, very thin to thin- thin- to medium-bedded, bedded, light olive-gray, yellowish-gray, poorly very finely crystalline; sorted, very fine to contains scattered sand medium-grained...... 5 0 grains ...... 10 Sandstone, crossbedded, Sandstone, thin- to medium- thin- to medium-bedded, bedded, yellowish-gray, yellowish-gray, fine- to limy, fine- to medium- medium-grained ...... 5 0 grained; grains exhibit sec­ Sandstone, medium-bedded, ondary growth ...... 5 8 yellowish-gray, very fine Limestone, medium-bedded, to medium-grained; grains light olive-gray, oolitoid, exhibit secondary dense to finely crystalline; growth...... 5 0 contains scattered sand grains Sandstone, thin- to medium- and white, medium to coarse bedded, yellowish-gray, calcite crystals ...... 1 8 limy, fine- to medium- Limestone, thin-bedded, grained; grains exhibit light olive-gray, very sandy, secondary growth ...... 5 0 - finely crystalline ...... 4 Limestone, thin-bedded, Limestone, medium-bedded, light olive-gray, sandy, very light olive-gray, finely to finely granular; medium-crystalline; con- ostracods...... 2 tains scattered sand grains, Limestone, medium-bedded, dense limestone granules, and light olive-gray, oolitic, very cryptozoon structures... 9 finely granular; Sandstone, thin- to medium- ostracods ...... 10 bedded, yellowish-gray, Sandstone, medium-bedded, limy, fine- to medium- yellowish-gray, very limy, grained...... 2 9 fine- to medium-grained; Sandstone, thin- to medium- grains exhibit secondary bedded, yellowish-gray, growth ...... 2 0 limy, fine- to medium- Sandstone, medium-bedded, grained; thin limestone yellowish-gray, limy, fine- stringers in lower one-third to medium-grained; grains of unit ...... 2 6 exhibit much secondary Limestone^ thick-bedded, growth ...... 2 3 light olive-gray, oolitic, Sandstone, medium-bedded, dense to very finely granular; yellowish-gray, fine- to contains scattered sand grains, medium-grained; grains limestone granules, and some exhibit secondary white medium-crystalline cal- growth ...... 5 0 cite; ostracods ...... 1 9 Sandstone, medium-bedded, Limestone, very thin to thin- yellowish-gray, limy, fine- bedded, yellowish-gray, to medium-grained ...... 5 0 sandy, very finely Sandstone, medium-bedded, granular...... 1 3 yellowish-gray, fine- to Sandstone, thick-bedded, medium-grained; grains yellowish-gray, slightly exhibit secondary limy, fine- to medium - growth...... 5 0 grained; grains exhibit much Sandstone, thin- to medium- secondary growth...... 5 8 bedded, yellowish-gray, Sandstone, thick-bedded, slightly limy, fine- to yellowish-gray, limy, medium-grained; grains very fine to medium-grained; exhibit secondary grains exhibit much secondary growth...... !0 0 growth ...... 4 3 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Limestone, medium-bedded, Limestone, medium-bedded, light olive-gray, oolitoid, light olive-gray, oolitic, dense to finely crystalline; dense; contains scattered contains scattered sand sand grains and thin sand­ grains ...... stone stringers...... 5 0 Sandstone, medium- to thick- Sandstone, medium-bedded, bedded, yellowish-gray, yellowish-gray to white, limy, very fine to medium- very limy, fine- to medium- grained; grains exhibit grained; contains some secondary growth ...... white coarse calcite Limestone, very thin to crystals ...... medium-bedded, light Limestone, platy to very olive-gray, oolitic, dense; thin bedded, light olive- contains scattered sand gray, oolitic, dense; con­ grains ...... tains scattered sand grains; Limestone, very thin to medium- grades into sandstone above bedded, light olive-gray, and below ...... oolitic, dense to finely crystal­ Sandstone, thin- to medium- line; contains thin sandstone bedded, yellowish-gray, stringers...... limy, fine- to medium- Limestone, medium-bedded, grained...... light olive-gray, oolitic, Limestone, thin-bedded, dense; contains scattered light olive-gray, sandy, sand grains...... 1 6 finely crystalline...... Sandstone, thin- to medium- Limestone, medium-bedded, bedded, yellowish-gray, light olive-gray, oolitic, very limy, fine- to dense; contains scattered medium-grained ...... sand grains and thin sand­ Limestone, thin-bedded, stone stringers...... light olive-gray, oolitic, very Limestone, medium-bedded, finely granular; contains light olive-gray, oolitic, scattered sand grains...... dense; contains scattered Sandstone, medium-bedded, sand grains...... yellowish-gray to white, limy, Sandstone, medium-bedded, fine- to medium-grained; yellowish-gray, limy, fine- contains olive-gray, dense, to medium-grained ..... limestone granules in the Limestone, very thin to lower 1 inch...... thin-bedded, light olive- Limestone, medium-bedded, gray, oolitoid, dense to light olive-gray, oolitic, finely crystalline; con­ dense to finely crystalline; tains scattered sand contains scattered sand grains ...... grains ...... Limestone, medium-bedded, Limestone, very thin to thin- yellowish-gray, sandy, bedded, light olive-gray, finely crystalline; contains oolitic, dense to very finely some flattened limestone granular; contains some granules ...... white coarse calcite Limestone, thin-bedded, crystals ...... light olive-gray, oolitic, Limestone, thin- to medium- dense; contains scat­ bedded, light olive-gray, tered sand grains ...... dense to finely crystalline; Base of section at river level. contains scattered sand grains ...... 186 7 Limestone, thin-bedded, light olive-gray, sandy, finely crystalline...... B. Section of the Everton formation on the south side Limestone, medium- of the Buffalo River, 50 yards upstream from bedded, yellowish- the mouth of Mill Creek in the NEi sec. 7, gray, very sandy, T. 16 N,, R. 20 W., Newton County, Ark. finely crystalline ...... Base of section at river level. Limestone, thin-bedded, light olive-gray, Carboniferous (Mississippian) rocks: oolitic, dense; con­ Boone formation: tains scattered sand St. Joe limestone member. grains ...... Basal sandstone member. Ft in Ft in Ordovician rocks: Ordovician rocks Continued Ever ton formation: Everton formation Continued Jasper member: Dolomite, medium- Limestone, medium- bedded, brownish- bedded, light olive - gray, finely crystalline; gray, slightly oolitic, contains scattered sand dense; contains pyrite, grains...... 1 4 especially in the upper Dolomite, thin-bedded, 6 inches ...... 1 7 brownish-gray, sandy, Limestone, thin-bedded, finely crystalline ...... 3 light olive-gray to brownish- Sandstone, medium-bedded, gray, sandy, oolitic, dense yellowish-gray to white, to finely crystalline; contains limy, slightly dolomitic, pyrite ...... 4 fine- to medium-grained; Sandstone, thin-bedded, light grains exhibit secondary olive-gray, limy, medium- growth ...... 1 1 grained...... 4 Dolomite, medium-bedded, Sandstone, medium-bedded, light olive-gray, very yellowish-gray to light sandy, finely olive-gray, very limy, fine- crystalline ...... 3 10 to medium-grained; contains Sandstone, medium-bedded, limestone granules; yellowish-gray to white, ostracods ...... slightly limy, fine- to Limestone, medium- medium-grained; grains bedded, light olive-gray, exhibit much secondary oolitic, dense; contains growth ...... 1 3 white medium-sized calcite Sandstone, medium-bedded, crystals; ostracods ...... 1 3 yellowish-gray to white, Sandstone, medium-bedded, slightly dolomitic, slightly yellowish-gray, limy, limy, fine- to medium- fine-grained ...... 1 0 grained ...... Limestone, thin-bedded, Sandstone, medium-bedded, light olive-gray, oolitic, light olive-gray, very dense...... 2 dolomitic, fine- to Sandstone, medium-bedded, medium-grained ...... yellowish-gray, very Sandstone, medium-bedded, limy, fine-grained ...... 4 2 light olive-gray to white, Limestone, medium-bedded, dolomitic, slightly limy, light olive-gray, oolitic, fine- to medium-grained; dense to finely crystalline; contains thin stringers of ostracods ...... 4 0 limy sandstone and dolomite Limestone, medium-bedded, with scattered sand light olive-gray, oolitic, grains ....'...... 3 11 dense to very finely gran­ Dolomite, medium-bedded, ular; ostracods ...... 4 3 brownish-gray, finely Limestone, medium-bedded, crystalline; contains scat­ light olive-gray, oolitic, tered sand grains'...... dense to very finely Sandstone, medium-bedded, granular ...... 5 0 yellowish-gray, Urny, Limestone, medium-bedded, dolomitic, fine- to medium - light olive-gray to light grained...... 3 0 brownish-gray, oolitoid, Sandstone, medium-bedded, very finely granular to yellowish-gray, fine- ts finely crystalline; contains medium-grained; grains scattered sand grains...... 5 0 exhibit secondary Sandstone, medium-bedded, growth...... yellowish-gray, slightly Dolomite, medium-bedded, limy, fine-grained; grains brownish-gray, finely exhibit much secondary crystalline ...... growth...... 4 0 Sandstone, medium- to Sandstone, medium-bedded, thick-bedded, yellowish- yellowish-gray, slightly gray to light olive-gray, limy, fine-grained; grains very dolomitic, fine- to exhibit much secondary medium-grained...... 3 10 growth ...... 5 0 Dolomite, medium-bedded, Sandstone, medium-bedded, medium dark gray, dense; yellowish-gray, limy, contains scattered sand fine- to medium-grained; grains ...... 6 0 grains exhibit secondary Base of section at river level growth ...... 5 0 (Base of Jasper member) 74 4 10 C. Section of the Everton formation on the north side Ft. in of the Little Buffalo River 50 yards upstream Ordovician rocks Continued from the junction with Buffalo River in the Everton formation Continued NEiNWi sec. 21, T. 16 N., R. 20 W., Newton Dolomite, medium- County, Ark. Base of section at river level. bedded, yellowish-gray to light brownish-gray, very sandy, finely to medium - Carboniferous (Mississippian) rocks: crystalline; contains white Boone formation: medium to very coarse calcite St. Joe limestone member. crystals; grades into overlying Basal sandstone member. unit...... 5 0 Ft in Sandstone, medium-bedded, Ordovician rocks: yellowish-gray to white, Everton formation: dolomitic, slightly limy, Jasper member: fine- to medium-grained; Sandstone, medium-bedded, grains exhibit secondary yellowish-gray, slightly growth...... 3 1 limy, fine- to medium - Dolomite, medium-bedded, grained; grains exhibit light brownish-gray, very secondary growth...... sandy, dense to finely Sandstone, thin-bedded, crystalline ...... 1 10 yellowish-gray, very limy, Sandstone, medium-bedded, fine- to medium-grained; very light gray to light grains exhibit some secondary brownish-gray, limy, growth ...... 2 6 medium-grained; grains Sandstone, medium-bedded, exhibit secondary very light-gray to yellowish- growth ...... 1 1 gray, very limy, fine- to Sandstone, medium- to thick- medium-grained; contains bedded, light brownish-gray, thin stringers of sandy very dolomitic, fine- to limestone...... medium-grained ...... 5 5 Limestone, medium-bedded, Dolomite, thick-bedded, light olive-gray, oolitic, brownish-gray and medium dense to finely crystalline; dark gray, dense to finely contains scattered sand grains; crystalline; contains scat­ ostracods ...... tered sand grains; Limestone, medium-beaded, ostracods...... 2 1 medium-gray to light olive- Sandstone, medium-bedded, gray, sandy, finely light brownish-gray to crystalline...... brownish-gray, dolomitic, Sandstone, medium-bedded, medium-grained ...... 3 6 yellowish-gray to white, Sandstone, medium-bedded, limy, fine- to medium- light brownish-gray to grained; grains exhibit light olive-gray, very dolo­ secondary growth...... mitic, medium- Limestone, thin- to medium- grained ...... 5 8 bedded, gray to brownish- Sandstone, medium-bedded, gray, oolitic, dense to finely very light gray to brownish- crystalline; ostracods ...... gray, dolomitic, fine- to Sandstone, medium- to thick- medium-grained ...... 5 0 bedded, yellowish-gray to Dolomite, medium-bedded, white, slightly limy, fine- light brownish-gray to to medium-grained; grains brownish-gray, dense to exhibit secondary finely crystalline; contains growth ...... white coarse calcite (Base of Jasper member) crystals ...... 9 Sandstone, medium-bedded, Sandstone, medium-bedded, light brownish-gray; very dark-gray to light olive- dolomitic, fine- to medium- gray, dolomitic, grained ...... medium-grained ...... 4 0 Sandstone, medium-bedded, Dolomite, thin- to medium- light brownish-gray, bedded, medium dark gray, dolomitic, medium- finely crystalline ...... 1 3 grained ...... Sandstone, medium- Dolomite, medium-bedded, bedded, yellowish- light olive-gray, finely gray, dolomitic, crystalline; contains scat­ fine- to medium tered sand grains and white grained...... 1 6 very coarse calcite crystals ...... 10

11 Ft in Ft in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, thin- to Sandstone, thin- to medium- medium-bedded, medium bedded, yellowish-gray to light gray, dense to finely white, limy, fine- to crystalline; contains scat­ medium-grained ...... 1 1 tered sand grains and white Dolomite, medium-bedded, coarse calcite crystals .... 3 10 medium dark gray to Dolomite, medium-bedded, brownish-gray, finely dark-gray to yellowish- crystalline; contains gray, sandy, finely scattered sand grains.... 2 5 crystalline; contains scat­ Sandstone, medium-bedded, tered sand grains and thin light brownish-gray to stringers of dolomitic yellowish-gray, dolomitic, sandstone ...... 2 2 fine-to medium- Dolomite, medium-bedded, grained...... 5 0 very light gray, pinkish- Newton sandstone member: gray, and yellowish-gray, Sandstone, medium- to thick- sandy, very limy, very bedded, yellowish-gray to finely granular to finely white, fine- to medium- crystalline; contains grained; grains exhibit scattered sand grains and secondary growth ...... 5 0 thin stringers of dolomitic Sandstone, medium- to sandstone ...... 4 0 thick-bedded, yellowish- Dolomite, medium-bedded, gray to white, fine- to medium-gray, very finely medium-grained; grains granular to finely crystal­ exhibit secondary line; contains scattered growth...... 5 0 sand grains ...... 1 2 Sandstone, medium- to Dolomite, medium-bedded, thick-bedded, yellowish- medium-gray to light olive- gray to white, slightly gray, dense to finely limy, fine- to medium- crystalline; contains scat­ grained; grains exhibit tered sand grains and white secondary growth...... 5 0 medium to coarse calcite Sandstone, medi-um-bedded, crystals ...... 5 0 yellowish-gray to white, Dolomite, thin-bedded, slightly limy, fine- to light-gray, very finely medium-grained; grains granular to finely crystal­ exhibit secondary line; contains scattered sand growth ...... 5 0 grains...... 1 2 Sandstone, medium-bedded, Dolomite, medium-bedded, yellowish-gray to white, medium dark gray, finely limy, fine- to medium-grained; crystalline; contains white grains exhibit secondary medium to coarse calcite growth...... 4 3 crystals ...... 2 10 (Base of Newton sandstone member) Dolomite, medium-bedded, Limestone, medium-bedded, olive-gray to light brownish- light-gray, sandy, oolitic, gray, dense; contains scattered dense to finely crystalline; sand grains...... ;. 1 2 contains scattered sand Dolomite, medium-bedded, grains at base; sand content light brownish-gray, sandy, increases upward ...... 2 0 dense...... 1 2 Limestone, medium- to Sandstone, medium- to thick- thick-bedded, medium- bedded, yellowish-gray to gray to light olive-gray, white, limy, fine- to dense; contains scattered medium-grained ...... 3 1 sand grains ...... 4 0 Dolomite, medium- Sandstone, thin- to medium- bedded, brownish- bedded, very light gray to black to medium white, limy, fine- to dark gray, dense; medium-grained...... 9 contains scattered Limestone, thin- to medium- sand grains ...... 9 bedded, medium-gray, Dolomite, medium-bedded, sandy, dense to finely medium dark gray, sandy, crystalline;ostracods... 1 0 dense ...... 8 Limestone, thin-bedded, Sandstone, thin-bedded, medium light gray, dense yellowish-gray, slightly to finely crystalline; con­ dolomitic, fine- to tains scattered sand medium-grained ...... 2 grains ...... 3

12 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Sandstone, medium-bedded, Limestone, medium-bedded, yellowish-gray, limy, fine- brownish-gray to light olive- to medium-grained...... 1 1 gray, dense to finely crystal­ Limestone, medium-bedded, line; cryptozoon medium light gray, slightly structures ...... ; oolitic, dense to finely Sandstone, thin- to medium- crystalline; contains scat­ bedded, yellowish-gray to tered sand grains ...... 1 2 light olive-gray, limy, fine- Sandstone, medium-bedded, to medium-grained ..... ( very light gray to yellowish- Limestone, fissile to thin- gray, limy, fine- to medium- bedded, medium light grained ...... gray, slightly sandy, Limestone, thin-bedded, oolitoid, dense to finely medium-gray, oolitic, dense crystalline ...... to finely crystalline; contains Sandstone, thin-bedded, scattered sand grains...... light-gray to yellowish- Sandstone, medium-bedded, gray, very limy, fine- to light olive-gray to yellowish- medium-grained; contains gray, limy, fine- to small flat limestone medium-grained ...... pebbles ...... Limestone, medium-bedded, Limestone, thin- to medium- light olive-gray to very bedded, medium-gray to light gray, oolitoid, sandy, light brownish-gray, dense; very finely granular; con­ contains thin stringers tains thin stringers of of white, limy limy sandstone ...... sandstone ...... Sandstone, medium-bedded, Sandstone, medium-bedded, very light gray, limy, light-gray to yellowish- fine- to medium-grained, gray, limy, fine- to contains limestone granules; medium-grained; contains wavy basal surface ...... dense limestone granules Limestone, medium-bedded, in the lower part ...... : light brownish-gray to olive - Limestone, very thin to gray, dense to finely crystal­ thin-bedded, medium- line; contains scattered sand gray to medium dark grains ...... gray, dense ...... Limestone, medium-bedded, Sandstone, medium-bedded, light brownish-gray to light-gray to yellowish- light olive-gray, sandy, gray, very limy, dense to finely medium-grained...... crystalline ...... 7 Sandstone, medium-bedded, Sandstone, thick-bedded, white, yellowish-gray, limy, limy, fine- to medium- medium-grained ...... : grained ...... '...... 2 6 Sandstone, medium-bedded, Sandstone, thick-bedded, white, very light gray to yellowish- limy, fine- to medium- gray, very limy, medium- grained ...... 5 0 grained ...... '. Sandstone, thick-bedded, white, Limestone, medium-bedded, limy, fine- to medium - medium-gray to light olive- grained ...... 4 0 gray, sandy, dense to finely Limestone, medium-bedded, crystalline; contains dense, medium-gray, dense to oolitic limestone pebbles finely crystalline; contains as much as 1 inch in diameter scattered sand grains ...... 1 0 in a matrix of very sandy Limestone, medium-bedded, limestone ...... medium-gray, sandy, dense Sandstone, medium-bedde'd, to finely crystalline...... 11 very light gray to yellowish- Limestone, medium-bedded, gray, very limy, medium- brownish-gray to olive- grained ...... gray, dense to finely Limestone, medium-bedded, crystalline; cryptozoon medium light gray to light structures...... 2 0 olive-gray, oolitic, dense; Sandstone, thin- to medium- contains scattered sand bedded, light brownish- grains...... gray to light-gray, very Limestone, medium-bedded, limy, fine- to medium- . medium light gray to light olive- grained ...... 11 gray, oolitic, dense......

13 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Limestone, medium-bedded, Jasper member Continued yellowish-gray, very Covered interval...... 6 sandy, dense to finely Limestone, thin-bedded, crystalline ...... light-gray, oolitic, dense; Limestone, thin- to medium- contains scattered sand bedded, olive-gray to light- grains...... 2 gray, oolitic, dense to finely Sandstone, thick-bedded, crystalline ...... very light gray to white, Sandstone, medium-^bedded, slightly limy, medium- light-gray to yellowish-gray, grained; grains exhibit limy, fine- to medium- secondary growth ...... 3 8 grained ...... Limestone, medium-bedded, Sandstone, thick-bedded to light-gray to very light massive, light-gray to gray, very sandy, dense to yellowish-gray, slightly finely crystalline ...... 1 6 limy, medium- to coarse­ Limestone, medium- to grained; grains exhibit thin-bedded, light-gray, secondary growth ...... oolitic, sandy, dense to Sandstone, thick-bedded to finely crystalline; sand massive, light-gray to content decreases upward; yellowish-gray, slightly ostracods...... 1 6 limy, medium-grained; grains Limestone, medium-bedded, exhibit secondary growth; very light gray to yellowish- (lower 4 feet of beds usually gray, dense to finely crystal­ below water level)...... line; contains scattered sand Base of section at river level. T8"7 T grains; ostracods ...... 8 Limestone, thin-bedded,'light- gray to yellowish-gray, dense to finely crystalline; D. Section of the St. Peter sandstone and Everton contains scattered sand formation on the east side of the Buffalo River grains ...... 1 1 and north of Hasty-Jasper road in the SW^SWi Limestone, thin-bedded, sec. 26, T. 16 N., R. 20 W., Newton County, light-gray to yellowish- Ark. Base of section about 4 feet above river gray, very sandy, finely level. crystalline...... 6 Sandstone, medium-bedded, Ft in white to very light gray, Carboniferous (Mississippian) rocks: very limy, medium - Boone formation: grained ...... 1 6 St. Joe limestone member. Covered interval ...... 6 Basal sandstone member. Limestone, medium- Covered interval ...... 7 0 bedded, light-gray, oolitic, dense to finely crystalline; Ordovician rocks: ostracods ...... 6 St. Peter sandstone: Covered interval ...... 6 Sandstone, medium-bedded, white Limestone, medium-bedded, to very light gray, very slightly yellowish-gray to light limy, medium-grained; grains olive-gray, dense to finely exhibit much secondary growth; crystalline; scattered sand quartzitic beds in middle of grains ...... 1 2 Q unit...... 2 O Limestone, medium-bedded, yellowish-gray to light olive-gray, very sandy, Everton formation: finely crystalline...... 3 Jasper member: Limestone, medium-bedded, ' Limestone, platy to thin- yellowish-gray to light bedded, light-gray, olive-gray, dense to finely dense ...... 1 2 crystalline; contains scat­ Sandstone, thin-bedded, very tered sand grains...... 1 0 light gray, very limy, medium- Sandstone, thin-bedded, white grained ...... 8 to very light gray, very Limestone, platy to thin- limy, fine- to medium- bedded, light-gray, grained ...... 11 dense ...... 1 3 Limestone, medium-bedded, Limestone, medium-bedded, very light gray to light- light-gray, oolitic, dense; gray, oolitoid, dense to finely contains scattered sand crystalline; contains scattered grains ...... 2 9 sand grains ...... 5

14 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Jasper member Continued Jasper member Continued Sandstone, thin-bedded, very Sandstone, medium- light gray to yellowish- bedded, white to very light gray, very limy, medium - gray, very slightly limy, grained ...... fine- to medium-grained; Sandstone, medium-bedded, grains exhibit secondary light-gray, medium-grained; growth ...... 10 grains exhibit secondary Limestone, thin-bedded, growth ...... very light gray to yellowish- Limestone, medium-bedded, gray, dense to finely crystal­ medium light gray, oolitoid, line; contains scattered sand dense to finely grains ...... crystalline ...... 2 3 Sandstone, medium-bedded, Limestone, thin-bedded, very light gray to white, light-gray to light olive- limy, medium-grained .... 11 gray, silty, oolitic, dense Limestone, thin-bedded, to finely crystalline ...... light-gray to yellowish- Limestone, medium-bedded, gray, oolitoid, finely light-gray, oolitic, dense to medium-crystalline; to finely crystalline; ostracods ...... ostracods ...... 3 11 Sandstone, medium- to Limestone, thick-bedded, thick-bedded, light-gray light olive-gray, oolitic, to white, limy, fine- to dense to finely crystalline; medium-grained; grains contains scattered sand exhibit secondary grainsjostracods, growth ...... trilobites ...... Limestone, thin-bedded, Limestone, medium-bedded, very light gray, sandy, very light gray to yellowish- dense to finely gray, oolitoid, sandy, finely crystalline ...... crystalline; contains limestone Sandstone, medium-bedded, granules; ostracods ...... white to very light gray, Limestone, medium-bedded, slightly limy, fine- to very light gray to light-gray, medium-grained; grains oolitic, dense to finely crystal­ exhibit secondary line; ostracods ...... growth ...... Limestone, medium-bedded, Sandstone, thin-bedded, light-gray to very light gray, white to very light gray, oolitoid, dense to finely very limy, fine- to crystalline; contains scat­ medium-grained; con­ tered sand grains...... 11 tains a limestone Limestone, thin-bedded, very stringer i to 1 inch thick light gray, oolitoid, dense at top of unit ...... to finely crystalline; con­ Limestone, thin-bedded, tains scattered sand grains; very light gray to yellowish- ostracods ...... 1 6 gray, dense to medium- Limestone, platy to very crystalline; contains scat­ thin bedded, light-gray to tered sand grains; light brownish-gray, sandy, ostracods ...... dense to finely crystalline; Sandstone, medium-bedded, ostracods...... yellowish-gray to white, Limestone, thin- to medium- limy, fine- to medium- bedded, very light gray to grained ...... yellowish-gray, finely to Sandstone, medium-bedded, medium-crystalline; yellowish-gray to white, ostracods ...... quartzitic, fine- to medium- Limestone, very thin grained ...... bedded, light-gray to very Sandstone, medium-bedded, light gray, silty, dense to yellowish-gray to white, medium-crystalline; ostracods; limy, fine- to medium- unit weathers back ...... grained ...... Limestone, medium- Sandstone, medium-bedded, bedded, medium light white to very light gray, gray to brownish- limy, fine- to medium- gray, oolitic, dense grained; contains stringers to finely crystalline; of sandstone with siliceous ostracods ...... cement ...... 15 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Jasper member Continued Dolomite, medium- to Limestone, medium- thick-bedded, light- bedded, very light gray gray, sandy, dense to to yellowish-gray, finely crystalline; dense to medium-crystal­ ostracods ...... line; contains scattered Dolomite, thick-bedded, sand grains; ostracods ..... light-gray, dense to Limestone, medium- finely crystalline ...... 5 7 bedded, very light gray Covered interval ...... 3 7 to yellowish-gray, sandy, Dolomite, medium-bedded, dense to medium-crystal­ light-gray, sandy, dense line; ostracods ...... to finely crystalline ...... 1 2 Sandstone, medium-bedded, Covered interval ...... 5 0 light-gray to white, limy, Sandstone, medium-bedded, medium- to fine-grained; very light gray to white, grains exhibit secondary slightly dolomitic, growth; ostracods ...... 5 0 medium-grained...... (Base of Jasper member) Covered interval ...... 10 Dolomite, thick-bedded, Sandstone, medium-bedded, medium light gray to very light gray to white, light brownish-gray, slightly dolomitic, medium- sandy, dense to finely grained; grains exhibit crystalline...... secondary growth...... 11 Sandstone, thin-bedded, Dolomite, medium-bedded, light-gray to dense, limy, medium-gray to medium dolomitic, medium- light gray, dense to finely grained ...... crystalline; contains scat­ Dolomite, medium- to thick- tered sand grains ...... 10 bedded, medium light gray Sandstone, medium-bedded, to light brownish-gray, very light gray to white, sandy, dense; contains slightly dolomitic, medium- scattered sand grains and grained; grains exhibit thin stringers of dolomitic secondary growth ...... 10 sandstone ...... 4 3 Covered interval ...... 7 0 Dolomite, medium-bedded, Newton sandstone member: medium-gray to brownish- Sandstone, medium- to thick- gray, very sandy, dense to bedded, very light gray to finely crystalline...... 4 5 white, medium-grained; Sandstone, medium-bedded, grains exhibit secondary white to very light gray, growth...... medium-grained; grains Sandstone, medium- to exhibit secondary thick-bedded, very light growth ...... 2 5 gray to white, medium- Sandstone, very thin bedded, grained; grains exhibit light-gray to white, quartz- secondary growth ...... 1 10 itic, slightly dolomitic, Base of section about 4 feet above river level. fine- to medium-grained.... Sandstone, medium-bedded, white to very light gray, E. Section of the St. Peter sandstone and Everton for­ slightly limy, medium- to mation at Carver near the north end of the coarse-grained; grains ex­ Buffalo River bridge on State Route 123, NWisec. 6, hibit secondary growth ..... 1 7 T. 15 N., R. 19 W. , Newton County, Ark. Dolomite, medium-bedded, light-gray to light brownish- gray, sandy, finely to Carboniferous (Mississippian) rocks: medium-crystalline; con­ Boone formation. tains thin sandstone Ft in_ stringers ...... Dolomite, thin- to medium- Ordovician rocks: bedded, light-gray to light 6 11 olive-gray, finely crystal­ Fern vale limestone line; contains white coarse Plattin limestone 32 7 dolomite crystals ...... 2 3 Dolomite, medium-bedded, St. Peter sandstone: light-gray, very sandy, Sandstone, soft, greenish- dense to finely white, very limy, fine- to crystalline ...... 2 10 medium-grained ...... 16 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued St. Peter sandstone Continued Everton formation Continued Covered interval ...... /.... . Jasper member Continued Sandstone, thin-bedded, white, Sandstone, medium-bedded, limy; similar to that above...... white, very limy, Covered interval...... medium-grained...... Sandstone, thin-bedded, greenish- Limestone, medium- to gray, slightly argillaceous, limy; thick-bedded, buff, medium- similar to that above ...... crystalline; contains scattered Dolomite, dull-gray, silty, very sand grains; grades downward finely granular; contains very thin into white limy fine-grained laminae of very fine grained sandstone ...... 11 sandstone ...... Limestone, medium-bedded, Sandstone, greenish-white, limy; buff, finely crystalline to similar to the sandstones dense ...... above ...... Sandstone, greenish-white, Dolomite, gray-buff, very finely limy, fine-grained ..... granular...... Dolomite, thin-bedded, Covered interval ...... brown, medium- Sandstone, white, limy, fine- to crystalline...... medium-grained...... Covered interval ...... Sandstone, thin-bedded, brown, Limestone, medium-bedded, dolomitic, fine-grained...... buff, microfossiliferous, Covered interval ...... finely crystalline; abundant Sandstone, thin-bedded, white to ostracods ...... 11 brown, dolomitic, fine­ Limestone, medium-bedded, grained ...... light-buff, sandy, finely Dolomite, very thin bedded, gray- crystalline ...... buff, sandy, fine-grained; Limestone, thin-bedded, ostracods ...... light-buff, sandy, finely Sandstone, medium-bedded, buff- crystalline ...... brown, dolomitic, fine-grained; Limestone, thin-bedded, and white fine- to medium-grained light-buff, oolitic or sandstone ...... microfossiliferous, dense; Covered interval...... calcite; sand grains in upper Sandstone, soft, very thin bedded, part...... pinkish- to greenish-white, fine- Limestone, thin-bedded, to medium-grained; grains exhibit light-buff, oolitic or secondary growth ...... microfossiliferous, sandy; Covered interval...... sand content increases Sandstone, medium-bedded, white, upward ...... limy, medium-grained; grains As above, but very thin exhibit secondary growth ...... 6 bedded ...... Limestone, thin-bedded, light-buff, finely figured, 54 10 finely crystalline ...... 10 Covered interval ...... 7 Everton formation: Limestone, thin-bedded, Jasper member: light-buff, finely figured, Dolomite, massive, dark- finely crystalline...... gray to brown, medium Sandstone, white, slightly to coarsely crystalline...... 8 limy, medium-grained; Sandstone, thin-bedded, white, grains exhibit secondary fine- to medium-grained .... 1 growth ...... Covered interval ...... 6 Sandstone, massive, white, Sandstone, medium-bedded, medium-grained...... white, fine- to medium- Limestone, gray-buff, grained ...... 2 microfossiliferous, Covered interval ...... 2 finely crystalline; Limestone, medium-bedded, abundant ostracods...... light-buff, slightly sandy, Sandstone, thin- to finely crystalline...... 1 3 medium-bedded, tan Limestone, medium-bedded, to white, fine- to buff, finely crystalline...... 11 medium-grained Limestone, medium-bedded, (usually below water buff, sandy ...... level) ...... Limestone, light-buff, oolitic or microfossiliferous, finely crystalline; grades downward into 52 buff sandy limestone ...'..... 1 17 F. Section of the St. Peter sandstone and Everton Ft. in. formation on the north side of the Buffalo River Ordovician rocks Continued in the SWiSEl sec. 31, T. 16 N., R. 19 W., Everton formation: Newton County, Ark. Base of section at river level. Jasper member: Dolomite, medium-bedded, brownish-gray, medium- Ft in crystalline; contains scattered Carboniferous (Mississippian) rocks: sand grains ...... 1 1 Boone formation: Sandstone, medium-bedded, St. Joe limestone member. white, limy, fine- to Basal sandstone member... medium-grained ...... 8 Dolomite, medium-bedded, (The gradational contact of the brownish-gray, finely to St. Joe limestone member and medium-crystalline; con­ the basal sandstone member is tains scattered sand exposed at the top of this unit. grains ...... 4 4 The contact of the basal sand­ Dolomite, medium-bedded, stone member and the under­ brownish-gray, slightly lying St. Peter sandstone is not silty, medium-crystalline; exposed; it lies somewhere in the contains scattered sand following covered interval.) grains ...... 4 7 Sandstone, medium-bedded, Covered interval 10 yellowish-gray to white, slightly limy, fine- to Ordovician rocks: medium-grained...... 1 4 St. Peter sandstone: Dolomite, thin-bedded, Sandstone, medium-bedded, light brownish-gray, silty, dusky-yellow, silty, limy, finely crystalline; contains fine- to medium-grained; coarse calcite crystals grains exhibit some secondary and thin stringers of yellowish- growth ...... 2 0 gray dolomitic fine- to Covered interval ...... 10 0 medium-grained Sandstone, thin- to medium-bedded, sandstone...... 2 3 yellowish-gray to white, slightly Covered interval ...... 1 0 limy, fine- to medium-grained; Sandstone, medium-bedded, grains exhibit some secondary brownish-gray, dolomitic, growth ...... 1 5 fine- to Dolomite, thin- to medium-bedded, medium-grained ...... 2 4 pale-brown, silty, finely granular; .Sandstone, medium-bedded, contains scattered sand yellowish-gray, limy, grains ...... 8 fine- to medium- Sandstone, medium-bedded, light- grained ...... 2 3 brown to white, quartzitic, slightly Limestone, medium-bedded, dolomitic, fine-grained; contains light olive-gray, oolitic, some white coarse dolomite dense to finely crystalline; crystals ...... 1 7 ostracods ...... 2 6 Dolomite, thin- to medium-bedded, Limestone, medium-bedded, pale-brown, silty, finely granular; light olive-gray, very contains scattered sand sandy, finely grains ...... 5 crystalline ...... 4 Sandstone, thick-bedded, dusky- Limestone, medium-bedded, yellow to light olive-gray, silty, light olive-gray, oolitic, dolomitic, very fine to fine-grained; dense to finely crystal­ the amount of dolomite increases line; ostracods ...... 1 4 upward in the unit; Limestone, medium-bedded, ostracods...... 2 11 light olive-gray, sandy, Covered interval ...... 9 0 finely crystalline ...... 9 Sandstone, deeply weathered and Limestone, medium-bedded, ' poorly exposed, medium-bedded, yellowish-gray, sandy, yellowish-gray to white, medium- finely crystalline ...... 1 1 to coarse-grained ...... 5 0 Sandstone, medium-bedded, Sandstone, medium-bedded, yellowish-gray, limy, yellowish-gray to white, slightly fine- to medium-grained; limy; grains exhibit secondary ostracods ...... 3 4 growth; slightly irregular basal Limestone, medium-bedded, surface ...... 5 8 light olive-gray, oolitic, finely to medium- crystalline ...... 5 38 8

18 Ft in Ft in Ordovician rocks -Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Jasper member Continued Jasper member Continued Sandstone, thin-bedded, Limestone, thin- to medium- yellowish-gray, limy, bedded, light olive-gray, fine- to medium-grained; finely to medium-crystalline; grades into overlying contains limestone granules; unit ...... 2 ostracods ...... Limestone, thin- to medium- Limestone, thin-bedded, bedded, light brownish- light olive-gray, sandy, gray, slightly oolitic, finely to medium- dense to finely crystalline.... 2 crystalline ...... Limestone, thick-bedded, Sandstone, thick-bedded, light brownish-gray, slightly yellowish-gray, limy, oolitic, finely medium-grained; grains crystalline ...... 4 exhibit secondary Limestone, thick-bedded, growth ...... 11 light brownish-gray, oolitic, Limestone, fine- to medium- finely crystalline; bedded, light brownish- ostracods ...... 2 gray, finely crystalline; Limestone, thick-bedded, contains scattered sand alternately sandy and grains ...... nonsandy, light brownish- Sandstone, medium-bedded, gray, oolitic, finely crystal­ yellowish-gray, limy, line; ostracods ...... 5 fine- to medium- Limestone, thin-bedded, light grained...... brownish-gray, sandy, finely (Base of Jasper member) crystalline ...... Sandstone, medium-bedded, Limestone, thin-bedded, light yellowish-gray, dolomitic, olive-gray, oolitic, finely fine- to medium- crystalline; contains medium- grained...... sized calcite crystals and Sandstone, medium-bedded, pyrite altered to limonite; light olive-gray to ostracods ...... yellowish-gray, dolomitic, Limestone, thin- to medium- medium-grained...... bedded, light olive-gray, Dolomite, medium-bedded, oolitic, finely crystalline; light brownish-gray, contains some thin stringers sandy, finely of sandy limestone...... 4 crystalline ...... Sandstone, thin- to medium- Sandstone, medium-bedded, bedded, pale-brown to white, light brownish-gray, limy, medium-grained; grains dolomitic, medium- exhibit secondary grained ...... growth...... 3 Sandstone, medium-bedded, Limestone, medium-bedded, yellowish-gray, limy, light brownish-gray, oolitic, medium-grained ...... 10 finely to medium- Sandstone, medium-bedded, crystalline ...... 11 light brownish-gray, very Sandstone, medium-bedded, dolomitic, fine- to medium- white, limy, fine- to grained ...... medium-grained ...... Sandstone, medium-bedded, Limestone, medium-bedded, yellowish-gray, slightly light brownish-gray, oolitic, limy, medium-grained; finely to medium- grains exhibit secondary crystalline ...... growth ...... Sandstone, medium-bedded, Dolomite, medium-bedded, yellowish-gray to white, brownish-gray, very limy, medium- sandy, finely grained ...... 2 crystalline ...... Limestone, medium-bedded, Dolomite, medium-bedded, brownish-gray, oolitic, finely brownish-gray, sandy, to medium-crystalline; finely crystalline...... ostracods ...... Dolomite, medium-bedded, Limestone, medium-bedded, brownish-gray, finely brownish-gray, finely to crystalline ...... medium-crystalline; con­ Dolomite, medium-bedded, tains limestone granules.... 1 brownish-gray, sandy, Sandstone, thick-bedded, finely crystalline ...... yellowish-gray, limy, medium - grained ...... 3 19 Ft in_ Ft jin, Ordovieian rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, sandy, finely yellowish-gray, limy, crystalline; contains thin medium-grained; contains stringers of yellowish-gray stringers of light brownish- fine- to medium-grained gray dolomitic medium- slightly dolomitic grained sandstone ...... 2 3 sandstone...... 5 0 Sandstone, medium-bedded, Dolomite, medium-bedded, yellowish-gray to light brownish-gray, sandy, brownish-gray, slightly finely to medium- limy, fine- to medium- crystalline...... 5 4 grained; contains stringers Dolomite, medium-bedded, of light brownish-gray dolo­ brownish-gray, dense to mitic fine- to medium- finely crystalline; contains grained sandstone...... 4 0 scattered sand grains ...... 5 0 Dolomite, very thin bedded, Sandstone, medium-bedded, brownish-gray, slightly yellowish-gray to brownish- sandy, finely crystalline .... 1 gray, dolomitic, fine- to Sandstone, medium-bedded, medium-grained; yellowish-gray, -limy, fine- ostracods...... 2 0 to medium-grained; con­ Dolomite, medium-bedded, tains stringers of light - brownish-gray, sandy, finely brownish-gray dolomitic to medium-.crystalline ...... 3 0 fine- to medium-grained Dolomite, medium-bedded, sandstone ...... 11 brownish-gray, finely to Newton sandstone member: medium-crystalline; con­ Sandstone, medium-bedded, tains some thin stringers of yellowish-gray, slightly sandy dolomite...... 5 4 limy, fine- to medium- Dolomite, thin- to medium- grained ...... 4 9 bedded, brownish-gray, Sandstone, medium- to thick- limy, finely to coarsely bedded, yellowish-gray, crystalline; contains many slightly limy, fine- to medium- white coarse calcite and grained ...... 3 8 dolomite crystals ...... 2 0 Sandstone, massive, yellowish- Dolomite, medium-bedded, gray, limy, fine- to medium - brownish-gray, finely grained; lime content increases crystalline; contains white downward; grains exhibit much coarse calcite crystals...... 2 6 secondary growth ...... 5 0 Dolomite, medium-bedded, (Base of Newton sandstone member) brownish-gray, finely Limestone, medium-bedded, light crystalline; contains scat­ olive-gray, sandy, finely tered sand grains...... 2 2 crystalline ...... 10 Sandstone, medium-bedded, Limestone, thin-bedded, olive- light brownish-gray, gray, slightly dolomitic, dolomitic, fine- to medium- dense to finely crystalline.... 4 grained ...... 1 0 Limestone, thin-bedded, olive- Dolomite, medium-bedded, gray, sandy, slightly dolomitic, brownish-gray, finely finely crystalline...... 7 crystalline; contains scattered Limestone, medium-bedded, sand grains ...... 1 0 light olive-gray, very sandy, Dolomite, medium-bedded, finely crystalline ...... 6 brownish-gray, finely crystal­ Sandstone, medium-bedded, light line; contains scattered olive-gray, very limy, sand grains ...... 2 9 medium-grained...... 7 Sandstone, medium-bedded, Limestone, medium-bedded, light brownish-gray, dolo­ medium-gray, finely crystal­ mitic, medium-grained ...... 1 10 line; contains white coarse Dolomite, medium-bedded, calcite crystals ...... 2 2 light brownish-gray, sandy, Sandstone, medium-bedded, finely crystalline ...... 1 9 yellowish-gray, slightly Dolomite, thin- to medium - limy to dolomitic, fine- to bedded, light brownish- medium-grained; grains gray, sandy, finely crystalline; exhibit secondary sand content increases upward growth ...... 2 5 in unit (few scattered sand Base of section at river level. grains at base, very sandy at top)...... 3 4 178

20 G. Section of the St. Peter sandstone and Everton formation on the north side of the Buffalo River Ordovician rocks Continued H IS. in the NE±NW± sec. 34, T. 16 N,, R. 19 W., Everton formation Continued Newton County, Ark. Base of section at river Jasper member Continued level. Sandstone, medium-bedded, yellowish-gray, slightly Ft in_ dolomitic, fine- to medium- Ordovician rocks: grained; grains exhibit Plattin limestone. secondary growth ...... 4 4 St. Peter sandstone: Dolomite, thin-bedded, Sandstone, poorly exposed, medium- grayish yellow green, silty, bedded, light-brown, silty, limy, finely crystalline; contains slightly dolomitic, fine­ scattered sand grains and grained ...... 4 0 some white coarse calcite Covered interval ...... i 13 0 crystals ...... 1 10 Sandstone, badly weathered, thin- Dolomite, medium-bedded, to medium-bedded, yellowish- brownish-gray, slightly gray, very fine to fine­ silty, finely crystalline...... 2 8 grained ...... 2 7 Dolomite, thin-bedded, Sandstone, medium-bedded, brownish-gray, medium- yellowish-gray, very fine to crystalline; contains scat­ fine-grained with scattered tered sand grains ...... 4 coarse grains; grains exhibit Sandstone, medium-bedded, secondary growth...... 4 7 light brownish-gray, dolomitic, Sandstone, medium-bedded, medium-grained ...... 2 4 crossbedded, yellowish-gray to Sandstone, medium-bedded, brownish-gray, fine-grained; yellowish-gray, very limy, grains exhibit secondary medium-grained; growth ...... 3 10 ostracods ...... 2 3 Sandstone, thin-bedded, yellowish- Covered interval ...... 3 0 .gray, fine- to medium- Limestone, medium-bedded, grained ...... 1 4 light olive-gray, oolitic, dense to finely crystalline; many ostracods ...... 2 0 Limestone, medium-bedded, light olive-gray, finely crystalline; contains Everton formation: limestone granules; Jasper member: ostracods ...... 1 0 Dolomite, thin- to medium - Limestone, medium-bedded, bedded,brownish-gray, light olive-gray, sandy, sandy, medium-crystalline; finely crystalline; contains contains thin stringers of limestone granules; dolomitic sandstone...... 4 1 ostracods ...... 2 11 Covered interval ...... 1 7 Limestone, medium-bedded, Dolojnite, thin-bedded, light olive-gray, oolitic, brownish-gray, sandy, dense to finely crystalline; finely crystalline...... 4 ostracods ...... 5 Dolomite, thin-bedded, dark- Dolomite, medium-bedded, gray, medium- light brownish-gray, medium- crystalline ...... 3 crystalline; contains white Dolomite, medium-bedded, coarse calcite crystals ..... 1 1 brownish-gray, sandy, Dolomite, thin-bedded, light finely crystalline ...... 3 10 brownish-gray, sandy, Dolomite, medium-bedded, medium-crystalline; con­ brownish-gray, medium- tains white coarse calcite crystalline; contains scat­ crystals ...... 4 tered sand grains in lower Limestone, medium-bedded, half of unit...... '...... 7 yellowish-gray to light olive- Dolomite, medium-bedded, gray, oolitic, finely crystal­ light-brown, sandy, finely line ; ostracods ...... 3 2 crystalline ...... 1 0 Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, slightly limy, light-brown to light olive- finely to medium- gray, dolomitic, medium- crystalline ...... 6 grained ...... 9 Sandstone, medium-bedded, Dolomite, medium-bedded, yellowish-gray, limy, fine- light brownish-gray, medium- to medium-grained; grains crystalline; slightly silty in exhibit secondary lower part ...... 2 7 growth ...... 3 6 21 Ft in_ Fi in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Jasper member Continued Dolomite, medium- Limestone, medium-bedded, bedded, light-gray to light olive-gray, oolitic brownish-gray, sandy, and oolitoid, finely crystal­ finely granular ...... 2 7 line; ostracods in lower Dolomite, medium-bedded, 4 inches ...... 2 2 brownish-gray, sandy, finely Sandstone, medium-bedded, granular; contains thin yellowish-gray, limy, fine- nonsandy dolomite to medium-grained; grains stringers ...... 1 0 exhibit secondary growth..... 2 1 Sandstone, thin-bedded, Covered interval ...... 5 light brownish-gray, limy, Limestone, thin- to medium- medium-grained ...... 4 bedded, light olive-gray, Dolomite, medium- to thick- oolitic, finely crystalline... . 8 bedded, brownish-gray, Covered interval ...... 5 sandy, finely Sandstone, thin- to medium- crystalline ...... 2 11 bedded, yellowish-gray, Dolomite, thin-bedded, medium-grained; grains brownish-gray, sandy, finely exhibit secondary crystalline; contains medium- growth...... 2 4 sized calcite crystals; (Base of Jasper member) ostracods ...... 4 Sandstone, thfn-bedded, yellowish- Dolomite, medium-bedded, gray, dolomitic, medium- brownish-gray, dense to grained ...... 4 very finely granular; con­ Dolomite, medium-bedded, tains scattered sand grains light brownish-gray, finely and white coarse calcite to medium-crystalline; con­ crystals ...... 2 6 tains medium-sized calcite Sandstone, medium- to thick- crystals and scattered sand bedded, brownish-gray, grains ...... 1 8 dolomitic, fine- to medium- Sandstone, thin-bedded, grained; contains white coarse yellowish-gray to light brownish- calcite crystals ...... 2 7 gray, very dolomitic, fine- to Dolomite, thin-bedded, medium -grained; brownish-gray, sandy, dense ostracods ...... 3 8 to very finely granular; con­ Sandstone, medium-bedded, tains thin stringers of light brownish-gray, very nonsandy dolomite ...... 1 0 dolomitic, fine- to Dolomite, medium- to thick- medium-grained ...... 4 11 bedded, brownish-gray, very Dolomite, medium-bedded, sandy; contains white coarse light brownish-gray, sandy, calcite crystals ...... 4 8 very finely granular; contains Sandstone, medium-bedded, .white coarse calcite yellowish-gray, limy, fine- crystals ...... 2 10 to medium-grained ...... 8 Dolomite, medium-bedded, Sandstone, medium-bedded, light brownish-gray, slightly light brownish-gray, limy, sandy, finely dolomitic, fine- to medium- crystalline ...... 4 11 grained ...... 10 Dolomite, thin- to medium- Sandstone, medium-bedded, bedded, brownish-gray, yellowish-gray, limy, fine- finely crystalline; cryptozoon(?) to medium-grained ...... 6 structures ...... I 2 Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, finely light brownish-gray, very crystalline...... 6 dolomitic, fine- to coarse­ .Sandstone, medium-bedded, grained; slightly limy in light brownish-gray, dolomitic, upper half ...... 2 7 fine- to medium- Sandstone, thin- to medium- grained ...... _ 6 bedded, yellowish-gray, Sandstone, medium-bedded, slightly limy, medium-grained; yellowish-gray, limy, fine- grains exhibit secondary to medium-grained ...... 6 growth ...... 11 Sandstone, medium- Dolomite, thin-bedded, brownish- bedded, light brownish- gray, dense ...... 2 gray, dolonritic, fine- Sandstone, thin-bedded, to medium- yellowish-gray, slightly limy, grained ...... 1 0 medium-grained ...... 3

22 Ft in_ Ft i Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, thin-bedded, dark- Dolomite, medium- gray, sandy, siliceous, bedded, light brownish- dense...... 4 gray, finely crystalline; Dolomite, medium-bedded, contains scattered sand brownish-gray, very sandy, grains ...... 1 0 finely to medium- Dolomite, medium-bedded, crystalline ...... 1 8 light brownish-gray, Dolomite, medium-bedded, finely crystalline...... 1 0 brownish-gray, finely to Dolomite, medium-bedded, medium-crystalline; contains brownish-gray to dark- scattered sand grains...... 1 0 gray, very finely granu­ Sandstone, thin-bedded, lar; contains scattered yellowish-gray, slightly sand grains increasing limy, medium-grained; in abundance grains exhibit secondary downward ...... 2 10 growth ...... 5 Sandstone, medium-bedded, Sandstone, thin- to medium- yellowish-gray, dolo­ bedded, light brownish- mitic, medium-grained; gray, dolomitic, fine- to grains exhibit secondary medium-grained...... 10 growth ...... 1 0 Covered interval ...... 1 0 Dolomite, medium-bedded, Sandstone, medium-bedded, light olive-gray to light yellowish-gray, slightly brownish-gray, slightly limy, fine- to medium - limy, finely crystalline; grained; grains exhibit second­ contains white coarse ary growth...... 2 7 calcite crystals; scattered Dolomite, medium-bedded, sand grains in the upper light brownish-gray, sandy, 4 inches ...... 2 9 finely crystalline; contains Sandstone, medium-bedded, thin stringers of limy yellowish-gray, dolomitic, sandstone...... 2 0 slightly limy, fine- to Sandstone, medium-bedded, coarse-grained ...... 3 3 yellowish-gray, limy, fine- Dolomite, medium-bedded, to medium-grained...... 1 6 brownish-gray, slightly Dolomite, medium-grained, limy, finely brownish-gray, sandy, crystalline ...... 10 finely crystalline; contains Sandstone, medium-bedded, stringers of nonsandy dolo­ yellowish-gray, dolomitic, mite and dolomitic slightly limy, fine- to sandstone ...... 2 6 coarse-grained ...... 2 11 Dolomite, medium-bedded, Sandstone, medium-bedded, light brownish-gray, finely yellowish-gray to light to medium crystalline ...... 1 4 olive-gray, dolomitic, Dolomite, medium-bedded, slightly limy, medium- light brownish-gray, finely grained ...... 2 10 to medium crystalline; Dolomite, medium-bedded, contains white fine to coarse light brownish-gray, calcite crystals ...... 4 11 slightly limy, medium- Dolomite, thin-bedded, light crystalline; contains scat­ olive-gray to brownish-gray, tered sand grains...... 1 2 finely to medium- Sandstone, medium-bedded, crystalline...... 1 5 yellowish-gray, dolomitic, Dolomite, medium-bedded, slightly limy, fine- to light olive-gray to brownish- coarse-grained; contains gray, dense to finely crystal­ white coarse calcite line; contains scattered crystals ...... 1 3 sand grains ...... 2 3 Newton sandstone member: Dolomite, medium-bedded, Sandstone, medium-bedded, light olive-gray to light yellowish-gray, slightly brownish-gray with streaks limy, fine- to coarse­ and spots of dark-gray, grained ...... 5 0 very finely granular; con­ Sandstone, thin- to medium- tains scattered sand bedded, yellowish-gray, grains ...... 1 0 limy, fine- to coarse­ Dolomite, medium-bedded, grained ...... 5 0 light brownish-gray, sandy, (Base of Newton sandstone member) very finely granular ...... 1 0

23 Ft in_ Ft in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Limestone, medium- Dolomite, medium-bedded, bedded, medium-gray, yellowish-gray to light sandy, very finely brownish-gray, sandy, granular ...... 1 4 slightly limy, medium- Limestone, medium-bedded, crystalline ...... 6 medium-gray, oolitic, very Dolomite, medium-bedded, finely granular; contains yellowish-gray to light scattered sand grains...... 2 1 brownish-gray, slightly Limestone, medium-bedded, limy, medium- medium-gray, oolitic, crystalline...... 10 very finely granular...... 1 6 Limestone, medium-bedded, Sandstone, medium-bedded, light-gray, sandy, very yellowish-gray, very limy, - finely granular...... 1 3 fine- to coarse-grained ..... 1 10 Limestone, medium-bedded, Dolomite, medium-bedded, yellowish-gray, very sandy, yellowish-gray to light very finely granular .... 4 4 olive-gray, very limy, Dolomite, medium-bedded, finely to medium- brownish-gray, sandy, crystalline ...... 2 6 slightly limy, finely Limestone, medium-bedded, crystalline; contains light-gray, very dolomitic, thin stringers of slightly slightly sandy, finely to limy, dolomitic medium-crystalline; loosely sandstone ...... 11 coiled cephalopods or Dolomite, thick-bedded, medium gastropods, small ostracods, light gray to light brownish- and pelecypods(?) ...... 10 gray, finely to medium- Limestone, medium-bedded, crystalline; contains scattered light-gray, very dolomitic, sand grains ...... 1 5 finely to medium - Dolomite, thick-bedded, crystalline ...... 1 3 light brownish-gray, sandy, Limestone, medium-bedded, finely crystalline...... 1 0 light-gray to light olive - Dolomite, platy to thin- gray, slightly dolomitic, bedded, light olive-gray, finely crystalline ...... 1 3 limy, finely to medium-crystal­ Sandstone, thin-bedded, line; sandy at base; well- yellowish-gray, limy, fine- developed cryptozoon to medium-grained ...... 2 structures ...... 3 1 Limestone, medium-bedded, Dolomite, medium-bedded, light-gray to light olive - yellowish-gray, very gray, slightly dolomitic, sandy, finely to medium- finely crystalline ...... 1 5 crystalline ...... 10 Limestone, medium-bedded, Dolomite, medium-bedded, yellowish-gray, very sandy, yellowish-gray to brownish- finely crystalline ...... 10 gray, finely to medium- Limestone, thin-bedded, crystalline; contains thin light olive-gray, oolitoid, stringers of sandy slightly dolomitic, finely dolomite ...... 4 1 to medium-crystalline ...... 1 5 Sandstone, medium-bedded, Sandstone, medium-bedded, yellowish-gray, dolomitic, yellowish-gray to light fine- to medium-grained; olive-gray, limy, fine- contains thin stringers of to coarse grained...... 6 brownish-gray dolomite; Limestone, medium-bedded, grains exhibit secondary yellowish-gray to light quartz growth...... 3 7 olive-gray, sandy, finely Dolomite, very thin to thin- crystalline ...... 1 1 bedded, brownish-gray, Limestone, medium-bedded, medium-crystalline..... 1 10 light olive-gray, slightly Dolomite, medium-bedded, dolomitic, very finely light brownish-gray, slightly granular to finely limy, medium-crystalline; crystalline; we 11-developed contains stringers of sandy cryptozoon dolomite ...... 3 9 structures ...... 3 10 Dolomite, medium-bedded, Sandstone, medium-bedded, medium light gray to yellowish-gray, limy, brownish-gray, medium- fine- to medium- crystalline; contains scat­ grained ...... 1 4 tered sand grains...... 4 4

24 Ft in_ - Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, medium-bedded, Dolomite, thin- to medium- brownish-gray to olive- bedded, light brownish- gray, medium - gray to light olive-gray, crystalline...... 3 5 finely to medium-crystalline; Dolomite, medium-bedded, contains thin siliceous sand­ brownish-gray to olive - stone stringers that weather gray, very sandy, medium- out in wavy bands...... 5 0 crystalline ...... 1 6 Dolomite, medium-bedded, Dolomite, medium-bedded, light olive-gray to brownish- light brownish-gray to gray, medium-crystalline; brownish-gray, sandy, to coarsely crystalline ...... 3 4 medium-crystalline; con­ Dolomite, thin- to medium- tains very sandy dolomite bedded, light brownish-gray to stringers in a darker, sandy to light olive-gray, finely dolomite; sand grains at the to medium-crystalline; con­ more sandy beds exhibit tains scattered sand grains secondary growth ...... 2 10 and thin stringers of sandy Dolomite, medium-bedded, dolomite ...... 5 7 medium-gray to brownish- Dolomite, medium-bedded, gray, medium-crystalline; light brownish-gray, finely contains thin, sandy dolo­ to medium-crystalline; con- mite stringers...... 6 tains thin sandy dolomite Dolomite, medium-bedded, stringers and scattered medium-gray to brownish- sand grains...... 5 0 gray, medium - Dolomite, medium- to crystalline ...... 3 5 thick-bedded, light brownish- Sandstone, medium-bedded, gray, finely to medium- yellowish-gray, dolomitic, crystalline; contains thin fine- to medium-grained. sandy dolomite stringers The dolomite cement increases and scattered sand downward and the unit becomes grains ...... 4 10 sandy dolomite at the Sandstone, thin-bedded, white base ...... 1 ) to medium light gray, Dolomite, medium-bedded, quartzitic, fine- to medium - brownish-gray, medium- grained; grains exhibit much crystalline ...... 2 5 secondary growth...... 8 Dolomite, medium-bedded, Dolomite, medium- to thick- light brownish-gray, slightly bedded, light olive-gray, limy, medium-crystalline; finely to medium crystalline; contains scattered sand contains sandy dolomite grains ...... 5 ) stringers less than 3 inches Dolomite, medium-bedded, thick and scattered sand light brownish-gray, medium- grains...... 5 2 crystalline; contains thin sandstone stringers and scat­ Base of section at river level tered sand grains ...... 5 281 9 Dolomite, medium-bedded, light brownish-gray, finely to medium-crystalline; contains H. Section of the St. Peter sandstone and Everton thin sandstone stringers and formation on the north side of the Buffalo River scattered sand grains ...... 5 in the SW|SWi sec. 26, T. 16 N. , R. 19 W. , Dolomite, medium-bedded, Newton County, Ark. Base of section 15 feet light brownish-gray, finely above river level. to medium-crystalline; con­ tains scattered sand grains... 4 Dolomite, thin- to medium- Carboniferous (Mississippian ) rocks: bedded, brownish-gray, finely Boone formation: to medium-crystalline; contains St. Joe limestone member. scattered sand grains ...... 3 Dolomite, thin- to medium- Covered interval1 to top of hill. Contains bedded, brownish-gray, finely float blocks of from the Boone for­ to medium-crystalline; contains mation and limestone from the St. Joe scattered sand grains and thin limestone member. sandstone stringers...... 1

25 Ft in. Ft in, Ordovician rocks: Ordovician rocks Continued St. Peter sandstone: Everton formation Continued Sandstone, thick-bedded to Jasper member Continued massive, white, fine- to medium- Dolomite, thin- to medium- grained; grains exhibit much bedded, light brownish-gray, secondary growth ...... 4 3 very finely granular; con­ Sandstone, medium- to thick- tains scattered sand grains bedded, yellowish-gray, fine- in the lower part ...... 2 0 to medium-grained; grains Sandstone, medium- to thick - exhibit secondary bedded, yellowish-gray to growth...... 3 11 white, limy, dolomitic, fine- Covered interval...... 58 0 to medium-grained ...... 1 11 Sandstone, medium- to thick- Dolomite, medium-bedded, bedded, yellowish-gray to dark-gray to brownish-gray, white, fine- to medium-grained; finely to medium-crystalline; grains exhibit secondary contains scattered sand growth ...... 6 9 grains ...... 10 Limestone, thick-bedded, olive- 72 IT gray, sandy, dense to finely crystalline; ostracods ...... 1 2 Sandstone, medium-bedded, greenish-gray and yellowish- Everton formation: gray, limy, fine- to medium- Jasper member: grained; contains sandy limestone Dolomite, thin- to medium- concretions 1 to 2 inches in bedded, medium-gray to diameter ...... 1 1 brownish-gray, slightly Limestone, very thin to thin- silty, finely to medium- bedded, yellowish-gray to crystalline...... 2 0 olive-gray, sandy, finely Sandstone, thin- to medium- crystalline...... 1 0 bedded, brownish-gray, very Limestone, very thin to thin- dolomitic, fine- to medium - bedded, olive-gray, oolitic, grained ...... 1 0 dense to very finely Sandstone, thin- to medium- granular...... 2 3 bedded, yellowish-gray, Dolomite, badly weathered, slightly limy, fine- to medium- very thin to thin-bedded, grained; grains exhibit pale-olive to grayish-olive, secondary growth ...... 10 limy, silty, finely Dolomite, medium- to crystalline...... 1 6 thick-bedded, brownish-gray, Dolomite, medium-bedded, very sandy, finely brownish-gray, finely to crystalline...... 3 3 medium-crystalline ...... 3 6 Dolomite, medium-bedded, Dolomite, medium-bedded, brownish-gray, sandy, finely light olive-gray to light crystalline...... 1 6 brownish-gray, slightly Sandstone, medium-bedded, limy, medium- yellowish-gray, dolomitic, crystalline ...... 1 9 slightly limy, fine- to Dolomite, medium-bedded, medium-grained...... 6 light olive ^gray to light Dolomite, medium-bedded, brownish-gray, slightly limy, -brownish-gray, medium- medium-crystalline ;contains crystalline ...... 1 7 scattered sand grains...... 2 0 Sandstone, medium- to thick- Dolomite, medium-bedded, bedded, yellowish-gray, limy, grayish-orange pink to pale- fine- to medium-grained; olive, medium-crystalline; grains exhibit secondary contains scattered sand growth...... 2 8 grains ...... 2 0 Dolomite (weathers back and Limestone, medium-bedded, could not be adequately olive-gray, oolitic, dense sampled), medium-bedded, to finely crystalline ...... 6 greenish-gray, silty, finely Dolomite, thick-bedded, light- crystalline ...... 1 0 gray to light brownish-gray, Dolomite, medium-bedded, slightly limy, medium- brownish-gray, slightly crystalline ...... 2 0 silty, finely to medium- Sandstone, medium-bedded, crystalline ...... 2 3 yellowish-gray to white, limy, Dolomite, thin- to medium- very fine to medium-grained; bedded, brownish-gray, grains exhibit secondary medium-crystalline...... 1 6 growth...... 2 3

26 Ft in_ Ft in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Jasper member Continued Dolomite, thin-bedded, Sandstone, medium-bedded, brownish-gray, sandy, light brownish-gray, very finely crystalline...... 3 dolomitic, fine- to medium- Sandstone, medium- to grained ...... 6 thick-bedded, light brownish- Limestone, medium-bedded, gray, dolomitic, fine- to medium-gray to light olive - medium-grained ...... 1 7 gray, sandy, finely Dolomite, medium-bedded, crystalline ...... 6 light brownish-gray, very Limestone, medium-bedded, sandy, finely crystalline..... 1 0 medium-gray to light olive - Dolomite, medium-bedded, gray, oolitic, dense to finely medium-gray to brownish- crystalline; ostracods...... 1 8 gray, sandy, very finely Sandstone, thick-bedded, granular...... 6 2 yellowish-gray to white, very Dolomite, medium-bedded, limy, fine- to medium- dark brownish-gray, finely grained ...... 2 9 crystalline ...... 1 0 Limestone, medium-bedded, me­ Sandstone, thin-bedded, white, dium-gray to olive-gray, oolitic, limy, dolomitic, fine- to dense to finely crystalline.... 1 3 medium-grained ...... 4 Sandstone, medium- to thick- Dolomite, medium-bedded, bedded, yellowish-gray to brownish-gray, very sandy, white, limy, fine- to medium- dense to finely grained ...... 1 7 crystalline ...... 3 0 Sandstone, medium- to Dolomite, thin- to medium - thick-bedded, yellowish-gray bedded, medium-gray to to brownish-gray, dolomitic, brownish-gray, dense ...... 1 4 limy, fine- to medium- Sandstone, medium-bedded, grained ...... 1 6 yellowish-gray, dolomitic, Dolomite, thick-bedded, quartzitic, fine- to medium- medium-gray to light olive - grained; grains exhibit gray, limy, finely to secondary growth...... 6 medium-crystalline; sandy Dolomite, thick-bedded, brownish- in the upper few gray, sandy, dense to very inches...... 1 1 finely granular ...... 2 4 Limestone, thin-bedded, olive- Dolomite, very thin to thin- gray, oolitic, finely bedded, brownish-gray, dense crystalline ...... 3 to very finely granular...... 5 Sandstone, medium-bedded, Sandstone, very thin to thin- yellowish-gray, limy, fine- to bedded, white, limy, dolo­ medium-grained...... 6 mitic, fine- to medium- (Base of Jasper member) grained ...... 3 Sandstone, medium-bedded, Dolomite, very thin to thin- yellowish-gray, dolomitic, bedded, brownish-gray, sandy, fine- to medium- very finely granular...... 4 grained ...... 6 Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, sandy, very brownish-gray to white, finely granular...... 4 0 dolomitic, fine- to medium- Dolomite, medium- to thick- grained; grains exhibit second­ bedded, brownish-gray, ary growth ...... 1 3 sandy, very finely granular; Dolomite, medium-bedded, contains thin stringers of dark brownish-gray, sandy, nonsandy dense dolomite .... 5 3 finely crystalline; Dolomite, medium-bedded, ostracods ...... 1 0 brownish-gray, sandy, very Dolomite, very thin to medium- finely granular ...... 3 7 bedded, dark brownish-gray, Sandstone, medium-bedded, dense to finely crystalline ... 2 3 white, fine- to medium- Dolomite, medium- to grained; grains exhibit thick-bedded, brownish- secondary growth...... 8 gray, very sandy, finely Dolomite, medium-bedded, crystalline ...... 3 0 brownish-gray to medium- Sandstone, medium- to gray, dense to finely thick-bedded, white, dolo­ crystalline; contains mitic, slightly limy, fine- scattered sand to medium-grained ...... 1 2 grains ...... 1 10

27 Ft in B in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Sandstone, medium-bedded, Sandstone, medium-bedded, light brownish-gray, brownish-gray, limy, dolo- dolomitic, limy, fine- to mitic, fine- to medium- medium-grained ...... 10 grained...... ;.... 2 6 Dolomite, medium-bedded, Dolomite, thick-bedded, brownish-gray to medium- medium-gray, finely gray, dense to finely crystal- crystalline ...... 1 6 line; contains scattered sand Sandstone, medium-bedded, grains ...... 2 0 light brownish-gray, dolo- Sandstone, thin-bedded, white, mitic, fine- to medium- limy, fine- to medium-grained; grained ...... 3 4 grains exhibit secondary Dolomite, medium-bedded, growth ...... 4 brownish-gray, finely Dolomite, medium-bedded, crystalline ...... 8 brownish-gray, sandy, finely Sandstone, medium-bedded, crystalline; contains thin light brownish-gray, stringers of nonsandy very dolomitic, fine- to medium - finely granular dolomite..... 4 11 .grained ...... 1 0 Dolomite, medium-bedded, Sandstone, medium-bedded, light brownish-gray, very light brownish-gray, very sandy, very finely dolomitic, fine-to "medium- granular...... 1 2 grained; contains thin Sandstone, medium-bedded, stringers of dolomite...... 4 0 yellowish-gray, limy, dolo- Dolomite, medium-bedded, mitic, fine- to medium- light brownish-gray, grained ...... 1 7 slightly limy, finely to Dolomite, medium-bedded, medium-crystalline; con- light brownish-gray, very tains pinkish-brown finely sandy, very finely crystalline calcite...... 1 0 granular ...... 2 0 Dolomite, medium-bedded, Sandstone, medium-bedded, brownish-gray, sandy, finely brownish-gray to yellowish- to medium-crystalline; con- gray, dolomitic, fine- to tains thin dolomitic and limy medium-grained ...... 1 0 sandstone stringera...... 1 6 Sandstone, medium-bedded, Newton sandstone member: yellowish-gray, limy, fine- Sandstone, thin- to medium- to medium-grained...... 6 bedded, yellowish-gray, Sandstone, medium-bedded, very slightly limy, very brownish-gray to yellowish- fine to medium-grained; gray, dolomitic, fine- to grains exhibit secondary medium-grained...... 7 growth ...... 4 2 Dolomite, thin- to medium- Sandstone, thin- to medium- bedded, light brownish-gray, bedded, yellowish-gray to sandy, dense to finely white, limy, fine- to crystalline ...... 8 medium-grained; more limy Dolomite, thin- to medium- at the base...... 4 9 bedded, light brownish- (Base of Newton sandstone member) gray, dense to finely crystal- Limestone, medium-bedded, line; contains scattered sand light olive-gray, sandy, grains...... 1 4 finely crystalline ...... 2 2 Dolomite, thin-bedded, light Limestone, medium-bedded, brownish-gray, dense to olive-gray, oolitic, dense finely crystalline ...... 4 to finely crystalline...... 2 1 Dolomite, medium-bedded, Limestone, medium-bedded, brownish-gray to medium- light olive-gray, sandy, gray, medium- finely crystalline...... 8 crystalline...... 5 0 Sandstone, medium-bedded, Dolomite, thin- to medium- yellowish-gray to light olive- bedded, brownish-gray to gray, limy, fine- to medium- medium-gray, finely to grained ...... 3 0 medium-crystalline; con- Dolomite, medium-bedded, tains scattered sand brownish-gray, sandy, finely grains ...... 4 4 to medium-crystalline ...... 6 Dolomite, medium-bedded, Limestone, medium-bedded, light brownish-gray to olive- medium-gray, dense to gray, slightly silty, finely to finely crystalline; contains medium-crystalline; contains scattered sand scattered sand grains...... 4 1 grains ...... 11 28 Ft in_ Ft in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Sandstone, thin-bedded, Dolomite, medium-bedded yellowish-gray, limy, brownish-gray, dense ...... 9 fine- to medium- Dolomite, medium-bedded, grained ...... 3 brownish-gray, sandy, finely Limestone, medium-bedded, crystalline ...... 2 0 medium-gray, finely Chert, medium-bedded, crystalline; contains scattered brownish-gray, oolitic, dense sand grains...... 1 9 (porous where weathered .... 5 Limestone, medium-bedded, Sandstone, medium-bedded, medium-gray to olive-gray, yellowish-gray, limy, fine- finely crystalline; contains to medium-grained ...... 5 scattered sand grains ...... 1 0 Limestone, medium-bedded, Sandstone, medium-bedded, olive-gray, dense to finely yellowish-gray, very limy, crystalline; cryptozoon fine- to medium-grained..... 9 structures ...... 1 11 Limestone, medium-bedded, Dolomite, medium-bedded, medium-gray to olive-gray, light brownish-gray, limy, finely crystalline; contains sandy, finely crystalline .... 10 scattered sand grains ...... 1 2 Limestone, medium- to thick- Sandstone, medium-bedded bedded, medium-gray, yellowish-gray, very limy, dense to finely crystalline; fine- to medium- cryptozoon structures...... 1 5 grained ...... 11 Dolomite, medium- to Limestone, thin- to medium- thick-bedded, brownish- bedded, olive-gray, oolitoid, gray, sandy, silty, limy, finely to medium finely crystalline ...... 2 0 crystalline...... 1 0 Dolomite, thin-bedded, Limestone, thin-bedded, olive - yellowish-gray to light gray, sandy, finely to brownish-gray, medium- medium crystalline ...... 4 crystalline ...... 3 Sandstone, thin- to medium- Sandstone, medium-bedded, bedded, white, limy, fine- to yellowish-gray, very medium-grained ...... 6 dolomitic, fine- to medium- Limestone, thin- to medium- grained ...... 3 0 bedded, olive-gray, oolitoid, Limestone, medium- to finely crystalline; thick-bedded, medium- ostracods ...... 1 9 gray to olive-gray, oolitoid, Sandstone, thin- to medium- dense to finely crystalline; bedded, light-gray, limy, cryptozoon structures ...... 3 0 fine- to medium- Limestone, medium-bedded, grained ...... 5 olive-gray, oolitic, dense to Limestone, medium- to thick- finely crystalline ...... 1 6 bedded, oolitoid, dense to Sandstone, medium-bedded, finely crystalline; cryptozoon yellowish-gray, limy, fine- to structures...... 2 7 medium-grained...... 6 Sandstone, medium-bedded, Limestone, medium-bedded, yellowish-gray to white, light olive-gray, sandy, limy, fine- to medium- finely crystalline...... 1 6 grained ...... 1 10 Limestone, very thin to Limestone, medium-bedded, medium-bedded, medium- olive-gray, sandy, slightly gray, dense ...... 1 1 oolitoid, finely Limestone, thin- to medium- crystalline...... 9 bedded, yellowish-gray, Sandstone, medium- to thick- very sandy, finely bedded, yellowish-gray, very crystalline...... 10 limy, fine- to medium- Limestone, thin- to medium- grained ...... 1 4 bedded, light olive-gray, Limestone, medium-bedded, doiomitic (especially in the olive-gray, sandy, dense to lower 6 inches), finely finely crystalline...... 8 crystalline ...... 2 9 Sandstone, medium- to thick- Sandstone, thin- to medium- bedded, yellowish-gray, very bedded, light-gray to limy, fine- to medium- yellowish-gray, dolomitic, grained ...... 2 2 limy, fine- to medium- Sandstone, thick-bedded, grained ...... 1 0 light brownish-gray, very Limestone, thin- to medium- dolomitic, fine- to medium- bedded, olive-gray, oolitoid, grained; contains thin stringers slightly dolomitic, dense to of dolomite...... 1 10 finely crystalline...... 1 7

29 Ft in Ft in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Sandstone, thin- to medium - Dolomite, medium-bedded, bedded, light-gray to white, light brownish-gray, limy, very limy, fine- to fine- to medium-crystalline; medium-grained...... 1 11 contains scattered sand Limestone, thin-bedded, grains; cryptozoon light olive-gray, very sandy, structures...... 3 9 finely crystalline ...... 3 Limestone, light olive-gray, Sandstone, thin- to medium- slightly dolomitic, dense to bedded, light-gray, very finely crystalline; cryptozoon limy, fine- to medium- structures...... 8 grained ...... 8 Dolomite, platy to very thin Limestone, thin-bedded, light bedded, light brownish- olive-gray, very sandy, gray, finely to medium- finely crystalline ...... 4 crystalline ...... 2 11 Limestone, medium-bedded, Dolomite, very thin to medium- olive-gray, dense to finely bedded, medium light gray, crystalline; cryptozoon finely to medium-crystalline; structures...... 2 11 contains scattered sand Limestone, thin-bedded, grains ...... 3 7 light-gray, very sandy, Dolomite, medium- to thick- finely crystalline; contains bedded, finely to medium- limestone granules...... 2 crystalline; contains scattered Limestone, thin-bedded, sand grains...... 1 8 olive-gray, dense to finely Sandstone, medium-bedded, crystalline ...... 3 medium light gray, very dolo­ Limestone, thin- to medium- mitic, fine- to medium- bedded, olive-gray, dense grained ...... 6 to finely crystalline; con­ Dolomite, medium- to thick- tains streaks of sandy bedded, medium-gray, finely dolomitic limestone...... 4 6 to medium-crystalline; con­ Limestone, thin- to medium- tains scattered sand bedded, light olive-gray, grains ...... 2 6 oolitic, dense to finely Dolomite, medium- to thick- crystalline; contains thin bedded, light brownish-gray, sand stringers; cryptozoon very sandy, finely crystalline; structures in the upper contains thin stringers of 18 inches ...... 5 2 dolomitic sandstone ...... 1 5 Limestone, platy to medium - Dolomite, platy to thin-bedded, bedded, light olive-gray, medium-gray, finely to medium- dense to finely crystalline; crystalline; contains scattered contains scattered sand sand grains...... 2 10 grains and sandy limestone Sandstone, thin-bedded, light- stringers ...... 4 9 gray to white, dolomitic, Limestone, thin- to medium- quartzitic, fine- to medium- bedded, olive-gray, oolitoid, grained; grains exhibit much dense to finely secondary growth...... 5 crystalline ...... 4 4 Dolomite, platy to thin-bedded, Limestone, platy to thin- medium-gray, finely to bedded, olive-gray, oolitoid, medium-crystalline; contains slightly dolomitic, dense to scattered sand grains ...... 8 finely crystalline ...... 4 2 Dolomite, thin- to medium- Sandstone, thin-bedded, light- bedded, light olive-gray, gray, slightly limy, quartz- medium-crystalline; contains itic; grains exhibit secondary scattered sand grains ...... 4 1 growth ...... 7 Dolomite, thin-bedded, light- Limestone, thick- gray, very sandy, finely bedded, olive-gray crystalline...... 3 to medium-gray, Sandstone, thin-bedded, oolitoid, dolomitic, yellowish-gray, quartzitic, dense to medium- slightly dolomitic, fine- to crystalline ...... 1 5 medium-grained; grains Sandstone, thin- exhibit secondary growth; bedded, light brownish- ostracods( ?) fragments ...... 1 2 gray to white, slightly Dolomite, thin- to medium- dolomitic, quartzitic, bedded, light brownish- fine- to medium- gray, finely to medium- grained; grains exhibit crystalline; contains scattered much secondary sand grains...... 4 3 growth ...... 8

30 Ft in_ Ft in_ Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, very thin to medium - Dolomite, very thin to bedded, medium light gray, medium-bedded, light finely to medium-crystalline; brownish-gray, sandy, cryptozoon( ?) structures..... 1 2 finely to medium- Dolomite, medium-bedded, crystalline...... 2 6 light brownish-gray, finely Dolomite, very thin to medium- to medium-crystalline; con­ bedded, light brownish-gray, tains scattered sand finely to medium- grains ...... 1 8 crystalline...... 6 Sandstone, medium-bedded, Dolomite, very thin to medium- light-gray, dolomitic, fine- bedded, light brownish-gray, to medium-grained; grains finely to medium-crystalline; exhibit secondary contains scattered sand growth ...... 6 grains ...... 6 Sandstone, thin- to medium- Dolomite, thin- to medium- bedded, light-gray, slightly bedded, light brownish-gray, dolomitic, fine- to medium- finely to medium- grained; grains exhibit crystalline...... 1 9 secondary growth...... 1 0 Chert, medium-bedded, Dolomite, thin- to medium- yellowish-gray, dense...... 6 bedded, medium light gray, Dolomite, thin- to medium- finely to medium-crystalline; bedded, light brownish-gray, contains scattered sand finely to medium- grains ...... 6 crystalline...... 1 9 Dolomite, thin- to medium- Dolomite, medium-bedded, bedded, medium light gray, light brownish-gray, finely finely to medium- to medium-crystalline; con­ crystalline...... 2 8 tains beds and stringers of Dolomite, thin- to medium- light brownish-gray oolitic bedded, medium light gray, chert ...... 4 1 finely to medium-crystalline; Dolomite, thin-bedded, light contains scattered sand brownish-gray, finely to grains ...... 6 medium-crystalline; contains Dolomite, thin- to medium- yellowish-gray oolitic dense bedded, light brownish-gray, chert in the upper 1 inch and finely to medium-crystalline; lower 6 inches...... 3 7 contains scattered sand Dolomite, thin- to medium- grains ...... 4 6 bedded, light brownish-gray, Chert, thin-bedded, white, medium-crystalline; contains dense (tripolitic in part) ..... 3 yellowish-gray dense and white Dolomite, thin-bedded, light tripolitic chert lenses ...... 2 0 brownish-gray, finely to Dolomite, thin- to medium-bedded, medium-crystalline; con­ bedded, brownish-gray, finely tains scattered sand finely to medium- grains ...... 3 crystalline...... 1 11 Sandstone, thin- to medium- Dolomite, medium- to thick- bedded, white to light-gray, bedded, brownish-gray, quartzitic, slightly dolo­ finely to medium- mitic, fine- to medium- crystalline...... 4 4 grained; grains exhibit Sandstone, medium-bedded, secondary growth...... 1 6 light brownish-gray, slightly Dolomite, thin- to medium- dolomitic, quartzitic, fine- bedded, light brownish- to medium-grained; grains gray, finely to medium- exhibit secondary crystalline; contains scattered growth ...... 1 6 sand grains ...... 3 9 Dolomite, medium-bedded, Sandstone, thin-bedded, light - medium-gray, finely to gray to light brownish-gray, medium-crystalline...... 2 10 dolomitic, fine- to medium- Covered interval ...... 2 0 grained; grains exhibit second­ Sandstone, medium-bedded, ary growth...... 1 1 light brownish-gray to Dolomite, thin- to medium- white, dolomitic, quartzitic, bedded, brownish-gray, finely fine- to medium-grained; crystalline...... 3 10 grains exhibit secondary Dolomite, very thin to medium- growth ...... 6 6 bedded, light brownish- Dolomite, medium-bedded, gray, finely to medium- brownish-gray, finely to crystalline ...... 1 0 medium-crystalline ...... 3 7 31 Ft in_ Ft _in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, medium-bedded, Jasper member Continued brownish-gray, finely to Dolomite, medium-bedded, medium-crystalline...... 3 3 brownish-gray to dark- Dolomite, medium-bedded, gray, medium-crystalline; brownish-gray, sandy, finely contains scattered sand to medium-crystalline ...... 6 grains ...... 5 0 Sandstone, thin-bedded, light Sandstbne, medium-bedded, brownish-gray, quartzitic, yellowish-gray to light fine- to medium- brownish-gray, dolomitic, grained...... 3 slightly silty and limy, fine- Dolomite, medium- to medium-grained ...... 1 1 bedded, brownish-gray, Dolomite, thin-bedded, finely to medium-crystalline; medium-gray to brownish- contains scattered sand gray, medium- grains...... 2 2 crystalline ...... 2 10 Dolomite, medium- Sandstone, thin-bedded, bedded, brownish-gray, yellowish-gray, limy, fine- sandy, finely to medium- to medium-grained...... 2 7 crystalline ...... 8 Covered interval ...... 1 8 Dolomite, medium- Dolomite, thin- to medium- bedded, brownish-gray, finely bedded, light olive-gray to medium-crystalline; con­ to light brownish-gray, tains scattered sand finely to medium-crystalline; grains ...... 8 contains scattered sand Dolomite, thick-bedded, grains ...... 2 6 brownish-gray, finely to Dolomite, thin- to medium- medium-crystalline; con­ bedded, light brownish-gray, tains scattered sand very finely granular; con­ grains...... 6 tains scattered sand Dolomite, thick-bedded, grains...... 1 2 brownish-gray, finely to Sandstone, thin-bedded, medium-crystalline ...... 3 9 yellowish-gray to light Dolomite, thin- to medium- brownish-gray, dolomitic, bedded, medium-gray to slightly limy, fine- to medium- light brownish-gray, finely grained ...... 8 crystalline ...... 2 6 Sandstone, thick-bedded, yellowish-gray, limy, fine- Base of section 15 feet above river level. to medium-grained; con­ 350 10 tains coarse white calcite « crystals ...... 1 10 Covered interval ...... 1 0 I. Section of the lower part of the St. Peter sandstone Dolomite, medium- to and the upper part of the Everton formation in the thick-bedded, medium- NEiSWisec. 26, T. 16 N. ,R. , 19 W. , Newton County, gray to brownish-gray, Ark. The bottom of the section is at the base of finely to medium-crystalline; a small waterfall at an approximate altitude of contains scattered sand 1,000 feet. graina...... 1 11 Dolomite, medium- bedded, light-gray to light Covered interval to top of hill . Represents brownish-gray, limy, sandy, most of the St. Peter sandstone'interval medium-crystalline ...... 1 0 and probably the Plattin limestone. Sandstone, medium-bedded, light-gray to yellowish-gray, Ft in limy, dolomitic, fine- to Crdovician rocks: medium-grained ...... 1 2 St. Peter sandstone (lower part only): Dolomite, very thin bedded, Sandstone, thin- to medium- yellowish-gray, limy, bedded, yellowish-gray, fine- medium-crystalline ...... 2 to medium-grained ...... 6 0 Sandstone, medium-bedded, yellowish-gray to light- gray, very limy, fine- to Everton formation (upper part only): medium-grained ...... 2 4 Jasper member: Limestone, thin-bedded, Dolomite, medium-bedded, brownish- light olive-gray, oolitic, gray to olive-gray, silty (?), finely dense...... 11 to medium-crystalline; contains Dolomite, thin-bedded, light- scattered sand grains; upper 1 foot gray to light brownish-gray, is slightly more sandy and limy, medium-crystalline ... 3 silty ...... 5 3

32 Ft in Ft in Ordovician rocks Continued Everton formation (upper part only) Con. Ordovician rocks Continued Jasper formation Continued Everton formation (upper part only) Con. Dolomite, thin-bedded, Jasper formation Continued medium-gray to brownish- Sandstone, thin- to medium- gray, finely crystalline; bedded, yellowish-gray, limy, contains some white coarse fine -grained ...... 3 0 calcite crystals ...... 1 2 Limestone, discontinuous, Covered interval...... 7 thin-bedded, olive-gray, Dolomite, medium- to oolitic, dense to finely thick-bedded, medium-gray crystalline; contains scat­ to brownish-gray, finely tered sand grains...... 4 crystalline...... 5 11 Sandstone, thin-bedded, Limestone, thin-bedded, yellowish-gray to white, light olive-gray, dense to limy, fine-grained; lower half finely crystalline; con­ of unit is quartzitic...... 1 0 tains scattered sand (Base of Jasper member) grains; ostracods ...... 1 3 Dolomite, medium-bedded, Limestone, thick-bedded, light brownish-gray to medium- light olive-gray, oolitic, gray, very sandy, dense dense to finely crystalline; to finely crystalline; ostracods...... 1 9 ostracods ...... 1 11 Dolomite, medium-bedded, Dolomite, thin- to medium- medium-gray, very limy, bedded, medium-gray to finely to medium-crystalline; brownish-gray, dense to finely contains scattered sand crystalline; contains scattered grains...... 10 sand grains...... 1 0 Dolomite, thin- to medium- Dolomite, thin- to medium- bedded, light-gray to light bedded, brownish-gray, brownish-gray, limy, finely sandy, dense to finely to medium-crystalline; con­ crystalline; ostracods ...... 8 tains scattered sand Dolomite, thin- to medium - grains...... 1 6 bedded, brownish-gray, Limestone, medium-bedded, dense to finely crystalline; light olive-gray, oolitoid, contains scattered sand dense to finely grains ...... 10 crystalline ...... 1 0 Dolomite, thin- to medium- Dolomite, thin- to medium- bedded, medium-gray, dense bedded, light brownish- to finely crystalline; con­ gray, finely to medium- tains scattered, sand grains crystalline; contains and sandy dolomite scattered sand grains ...... 1 1 stringers ...... 1 5 Dolomite, medium-bedded, Sandstone, thin- to medium- very light gray to yellowish- bedded, yellowish-gray to gray, very limy, finely to white (stained brown in spots), medium-crystalline ...... 1 7 fine- to medium-grained; Sandstone, medium-bedded, grains exhibit much secondary light-gray to light brownish- growth ...... 8 gray, limy, dolomitic, fine- Bottom of section at base of small waterfall. to medium-grained ...... 2 7 Limestone, thin- to medium- bedded, light olive-gray, dense to finely crystalline; many ostracods. This bed J. Section of the St. Peter sandstone and Everton pinches out in a short formation on the east side of the Buffalo River distance ...... 1 0 about i mile downstream from Mount Hersey Limestone, thin- to medium- in the SE|SWl sec. 25, T. 16 N. , R. 19 W., bedded, light olive-gray, Newton County, Ark. Base of section 65 feet dense to finely crystalline; above river level. many ostracods ...... 1 1 Sandstone, thin- to medium- Ft in bedded, very light gray to Ordovician rocks: white, very limy, fine- to Plattin limestone: medium-grained ...... 2 8 Cohered interval. (The contact Limestone, thin- to medium- between the Plattin limestone bedded, medium-gray to and the St. Peter sandstone olive-gray, oolitic, dense is present in this interval.) 21 to finely crystalline ...... 1 7

33 Ft in. Ft in. Ordovician rocks Continued Ordovician rocks Continued St. Peter sandstone: Everton formation Continued Sandstone, medium- to Jasper member Continued thick-bedded, light-gray and Limestone, medium-bedded, brownish-gray, medium- to light olive-gray, oolitic, coarse-grained; grains exhibit dense to finely crystalline; secondary growth ...... 5 contains scattered sand grains Sandstone, medium- to thick- and greenish silty patches; bedded, white and gray banded, pelecypod fragments, ostracods, slightly limy, medium- and and gastropods ...... 2 coarse-grained; grains exhibit Limestone, platy to thin- secondary growth ...... 5 bedded, light olive-gray and Sandstone, medium-bedded, light- light-gray, dense to finely gray to white, limy, medium- crystalline; contains silty grained; grains exhibit secondary partings between the beds; growth; irregular basal surface- sandy in the lower basal beds appear to fill hollows 2 inches ...... 1 in underlying limestone...... Sandstone, medium-bedded, very light gray to white, limy, fine-grained...... 1 Limestone, medium-bedded, light olive-gray and light- Everton formation: gray, oolitic, dense; con­ Jasper member: tains scattered sand grains, Limestone, medium-bedded, greenish silty patches, and light-gray, oolitic, dense limonite; upper 3 inches is to finely crystalline; con­ sandy, contains tains scattered sand ostracods ...... '...... 1 grains ...... Limestone, medium-bedded, Sandstone, thin-bedded, white, light brownish-gray and very limy, medium-grained light olive-gray, oolitic, grained...... finely crystalline; upper part Limestone, thin- to medium- contains scattered sand grains; bedded, light-gray and light lower part is sandy, contains pinkish-gray, oolitic, dense ostracods ...... 1 to finely crystalline; contains Sandstone, thin- to medium- scattered sand grains ...... bedded, very light gray to Sandstone, medium-bedded, white, medium-grained; con- white, very limy, medium- taina scattered coarse grains; to fine-grained; basal part grains exhibit secondary contains small flat limestone growth ...... pebbles ...... Limestone, medium-bedded, Limestone, light-gray, oolitic, light-gray to very light gray, dense to finely crystalline; sandy, oolitic, dense to finely contains scattered sand crystalline; ostracods in upper grains...... 1 foot 2 inches; lower 7 inches Limestone, light-gray to contains only scattered sand white, sandy, dense to finely grains ...... 1 crystalline...... Sandstone, medium-bedded, Sandstone, light-gray to white, very light gray to white, very very limy, fine- to medium- limy, fine- to medium- grained ...... grained ...... 1 Covered interval ...... Limestone, thin-bedded, Limestone, medium-bedded, light-gray and light brownish- light-gray, dense to finely gray, sandy; grades downward crystalline; contains small into a limy sandstone...... 1 flat, greenish-gray silty Limestone, medium-bedded, light and sandy limestone pebbles; bluish-gray, slightly oolitic, dense pelecypod fragments and to finely granular; contains scat-. gastropods...... tered sand grains ...... 2 Limestone, medium - Sandstone, medium-bedded, bedded, light-gray, yellowish-gray, limy, fine- and light olive-gray, to medium-grained...... oolitic, dense to finely Limestone, medium-bedded, crystalline; upper 2 inches medium light gray to very sandy and contains small light gray, oolitic, dense flat oolitic limestone to medium-crystalline; con­ pebbles...... 10 tains greenish-gray silt partings Covered interval ...... 5 and limonite; ostracods...... 2

34 Ft in_ Ft in_ Ordovician rocks Continued Crdovician rocks -Continued Everton formation Continued Everton formation -Continued Jasper member Continued Sandstone, medium- Limestone, medium- to thick- bedded, light brownish- bedded, light brownish- gray, dolomitic, gray to very light gray, fine- to medium- oolitic, dense to finely grained...... 1 10 crystalline; contains finely Dolomite, medium-bedded, to medium-crystalline calcite; brownish-gray, finely to ostracods ...... 3 4 medium-crystalline; con­ Limestone, medium-bedded, tains scattered sand medium-gray to light-gray, grains...... 7 light olive-gray, oolitoid, Sandstone, medium-bedded, dense to finely crystalline; light-gray to brownish - contains scattered sand gray, dolomitic, medium- grains; ostracods...... 3 0 grained ...... 3 2 Limestone, medium-bedded, Dolomite, medium-bedded, light-gray to very light light-gray and grayish-brown, gray, finely crystalline; sandy, finely crystalline; sand contains scattered sand content increases grains and stringers downward ...... 1 10 of sandy limestone; Sandstone, medium-bedded, ostracods ...... 4 0 gray-brown, dolomitic, fine- Limestone, medium-bedded, to medium-grained ...... 1 11 light-gray and light brownish - Dolomite, medium-bedded, gray, oolitic, dense to finely gray-brown, sandy, dense to crystalline; contains scattered finely crystalline...... 6 sand grains...... 2 5 Dolomite, medium-bedded, gray- Sandstone, thin-bedded, light- brown, dense to finely gray, medium-grained; grains crystalline; contains white exhibit secondary growth..... 2 3 calcite crystals ...... 11 Limestone, medium-bedded, Sandstone, medium-bedded, light brownish-gray and very light gray to white, olive-gray, oolitic, finely limy, medium-grained...... 10 to medium-crystalline; con­ Dolomite, medium-bedded, tains scattered sand grains; dark brownish-gray, finely ostracods ...... 2 0 to medium-crystalline; con­ Sandstone, medium-bedded, tains scattered sand yellowish-gray, limy, fine- grains...... 1' 1 to medium-grained; lime Sandstone, medium-bedded, cement increases very light gray, fine- to upward ...... 2 9 medium-grained; secondary Limestone, medium-bedded, growth ...... 7 very light gray to yellowish- Sandstone, medium-bedded, gray, oolitoid, finely to brownish-gray, dolomitic, medium -crystalline; medium-grained ...... 2 7 ostracods ...... 11 Dolomite, medium-bedded, Sandstone, thick-bedded, brownish-gray, dense to yellowish-gray, very limy, finely crystalline; contains fine- to medium-grained .... 3 3 coarse calcite crystals...... 11 (Base of Jasper member) Dolomite, medium-bedded, Dolomite, medium-bedded, light brownish-gray, gray, dense to finely sandy, finely crystal­ crystalline; Very sandy in line; contains stringers upper 1 inch and lower of very light gray to 3 inches. (This bed pinches white limy sandstone out 150 feet to the west.) .... I 5 and brownish-gray Sandstone, thin- to medium- dense dolomite ...... 5 2 bedded, light-gray, slightly Dolomite, medium-bedded, limy, quartzitic, medium- light brownish-gray, grained; grains exhibit second­ limy, finely to medium- ary growth...... 1 9 crystalline ...... 1 6 Sandstone, medium-bedded, Dolomite, medium-bedded, light-gray and grayish-brown, brownish-gray, sandy, dolomitic, fine- to medium- dense to finely crystalline; grained; contains stringers contains stringers of of gray dense dolomita ...... 5 4 dense dolomite and Sandstone, medium-bedded, medium-grained light brownish-gray, fine- to sandstone ...... 4 3 medium-grained ...... 6 35 Ft in_ Ft in_ Crdovician rocks Continued Crdovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, medium-bedded, Dolomite, medium-bedded, light brownish-gray to light brownish-gray, finely brownish-gray, sandy, crystalline; contains coarse dense to finely crystal­ calcite crystals ...... 3 3 line; contains stringers Dolomite, medium-bedded, of nonsandy dolomite with very dark gray, dense ...... 1 0 coarsely crystalline Dolomite, medium-bedded, calcite ...... 5 0 dark-gray to gray, sandy, Dolomite, thin- to medium- finely crystalline dolomite; bedded, light brownish - contains scattered sand gray to pale-brown, very grains and thin sandy dolo­ sandy, dense to finely mite stringers ...... 6 crystalline ...... 2 6 Sandstone, medium-bedded, Dolomite, thin- to medium- light brownish-gray, dolo­ bedded, brownish-black, mitic, medium-grained...... 1 3 finely to medium-crystalline; Sandstone, medium-bedded, contains scattered sand very light gray, limy, fine- grains ...... 1 1 to medium-grained; grains Sandstone, thin-bedded, exhibit secondary light-gray to yellowish- growth...... 2 0 gray, limy, fine- to Dolomite, medium-bedded, medium-grained; grains brownish-gray, finely crystal­ exhibit secondary line; contains coarse calcite growth...... 6 crystals ...... 8 Dolomite, thin- to medium - Sandstone, medium -bedded, bedded, light brownish- light-gray, dolomitic, gray to pale-brown, very medium-grained; grains sandy, dense to finely exhibit secondary crystalline...... 1 0 growth ...... 1 0 Dolomite, thin- to medium - Sandstone, medium-bedded, bedded, light olive-gray, light-gray to very light sandy, finely crystalline; gray, limy, fine- to medium- contains stringers of nonsandy grained; grains exhibit second­ dolomite...... 2 11 ary growth...... 2 0 Sandstone, thin-bedded, white, Sandstone, medium-bedded, limy, fine- to medium- light-gray to very light gray, grained; grains exhibit dolomitic, fine- to medium- secondary growth ...... 3 grained...... 3 0 Dolomite, thin- to medium- Sandstone, medium-bedded, bedded, medium-gray to very light gray to light-gray, brownish-gray, sandy, finely dolomitic, slightly limy, fine- crystalline; sand content to medium-grained ...... 4 6 decreases downward ...... 1 11 Newton sandstone member: Sandstone, medium-bedded, Sandstone, medium-bedded, very yellowish-gray to white, light gray to white, limy, dolomitic, .medium-grained; slightly dolomitic; fine- to grains exhibit secondary medium-grained; grains growth...... 2 0 exhibit secondary Sandstone, medium-bedded, growth...... 3 11 light brownish-gray, dolo­ Sandstone, medium-bedded, mitic, medium-grained ..... 3 5 very light gray to white, Dolomite, thin-bedded, light-gray, slightly limy, fine- to dense to finely crystalline; con­ medium-grained; grains tains coarse calcite crystals.. 5 exhibit secondary Dolomite, thin-bedded, light- growth...... 4 9 gray, sandy, dense to finely (Base of Newton sandstone member) crystalline; sand content de­ Dolomite, medium-bedded, creases downward ...... 1 4 light brownish-gray, very Dolomite, medium-bedded, sandy, finely granular to light-gray to gray, very finely crystalline ...... 2 6 finely granular to finely Dolomite, medium-bedded, crystalline; contains medium- light-gray and light brownish- crystalline calcite ...... 5 7 gray, very sandy, finely to Dolomite, medium-bedded, medium crystalline...... 2 3 light-gray and light olive - Dolomite, medium-bedded, gray, very finely granular brownish-gray, finely to finely crystalline; contains granular to finely coarsely crystalline calcite.... 4 10 crystalline...... 6 36 Ft in Ft Ordovician rocks Continued Crdovician rocks Continued Everton formation Continued Everton formation Continued Sandstone, medium - Sandstone, medium- to bedded, light-gray to thick-bedded, light- white, medium-grained; gray to light brownish- contains calcite gray, dolomitic, slightly crystals...... 2 limy, medium-grained ...... 2 Dolomite, medium-bedded, Dolomite, very thin to medium- medium light gray, sandy, bedded, light-gray to brownish- finely to medium-crystalline; gray, sandy, finely to medium- contains calcite crystalline; sand content crystals...... 3 increases upward ...... 3 Dolomite, medium-bedded, Dolomite, thin- to medium- medium light gray, limy, bedded, light-gray, finely finely to medium - to medium-crystalline; con­ crystalline ...... 1 tains scattered sand Dolomite, medium-bedded, grains ...... 5 light-gray to brownish- Dolomite, medium-bedded, gray, sandy, limy, finely light-gray, finely to to medium-crystalline ...... 5 medium-crystalline; contains Dolomite, medium-bedded, scattered sand light-gray, slightly limy, grains ...... 15 finely to medium-crystalline; Sandstone, very thin bedded, contains sandy dolomite beds light-gray to light olive - as much as 1 foot gray, dolomitic, fine- to thick...... 5 medium-grained ...... Dolomite, medium- to thick- Dolomite, medium-bedded, bedded, light-gray to gray, light-gray to light olive-gray, finely to medium-crystalline; finely to medium-crystalline; contains sandy dolomite beds contains scattered sand grains, as much as 1 foot wavy bedding; cryptozoon(?) thick ...... 5 structures ...... 4 Dolomite, medium-bedded, Dolomite, medium-bedded, light-gray to light olive - light brownish-gray, finely gray, limy, finely to to medium-crystalline; con­ medium-crystalline; con­ tains a silty bed 18 inches tains a sandy dolomite bed from top ...... 4 1 foot thick slightly above Dolomite, very thin to medium- the middle ...... 4 bedded, brownish-gray, finely Dolomite, medium-bedded, to medium-crystalline...... 2 10 light brownish-gray to gray, Sandstone, very thin to medium- sandy, finely to medium- bedded, brownish-gray, dolo­ crystalline; nonsandy in mitic, medium-grained ..... 1 upper 1 foot...... 4 Dolomite, very thin to Dolomite, medium-bedded, medium-bedded, brownish- light-gray to light brownish- gray, finely to medium- gray, sandy, finely to crystalline; contains medium-crystalline...... 5 scattered sand Dolomite, thin- to medium- grains ...... 1 bedded, light-gray and Dolomite, medium- light brownish-gray, sandy, bedded, light olive-gray, finely to medium-crystalline; finely to medium - nonsandy in lower crystalline...... 2 10 1 foot...... 4 Dolomite, medium-bedded, Dolomite, medium-bedded, light olive-gray, very sandy, light-gray and light brownish- finely to medium- gray, very sandy in part, crystalline...... 1 finely to medium- Dolomite, thin-bedded, crystalline ...... 5 brownish-gray, finely to Sandstone, medium- to medium-crystalline; sandy thick-bedded, light- in lower 6 inches ...... 2 gray to light brownish- Dolomite, medium-bedded, gray, dolomitic, slightly light olive-gray, finely to limy, medium- medium-crystalline...... 3 grained ...... 2 Dolomite, medium-bedded, Dolomite, thin-bedded, light light olive-gray, finely brownish-gray, finely to to medium-crys­ medium-crystalline...... talline...... 1

37 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, medium-bedded, Dolomite, medium-bedded, very light gray, very sandy, light brownish-gray to finely to medium- brownish-gray, finely crystalline...... 1 crystalline...... 1 Dolomite, medium-bedded, Dolomite, medium-bedded, light olive-gray, finely to light brownish-gray to grayish- medium-crystalline ...... 2 brown, sandy, finely crystal­ Dolomite, medium-bedded, line; becomes increasingly medium-gray to light-gray, sandy downward ...... 3 finely to medium- Sandstone, very thin bedded, crystalline...... 1 very light gray to white, Dolomite, medium-bedded, limy, fine- to medium- medium-gray to light-gray, grained ...... sandy, finely to medium- Dolomite, medium-bedded, crystalline ...... 1 light brownish-gray to grayish- Dolomite, medium-bedded, brown, finely crystalline; con­ medium-gray to light-gray, tains scattered sand finely to medium- grains ...... 1 crystalline ...... 3 Dolomite, medium-bedded, Sandstone, medium-bedded, light brownish-gray to dark light-gray to white, dolo­ brownish-gray, finely mitic, fine- to medium- crystalline; contains a 2-inch grained; .upper 3 inches is dolomitic sandstone stringer sandy dolomite ...... 3 near the top...... 5 Dolomite, medium-bedded, Dolomite, medium-bedded, light-gray, finely to medium- light-gray to white, sandy, crystalline; contains scat­ finely to medium-crystalline; tered sand .grains ...... 1 sand content increases Dolomite, medium-bedded, downward ...... 1 light-gray to light olive- Sandstone, medium-bedded, gray, finely to medium - light-gray to white, quartzitic, crystalline; contains scattered fine- to medium- sand grains...... 2 grained...... Sandstone, medium-bedded, Dolomite, medium-bedded, very light gray to white, light brownish-gray, finely dolomitic, medium- to medium-crystalline; con­ grained ...... 1 tains scattered Dolomite, medium-bedded, sand ...... 4 light-gray to light olive - Dolomite, medium-bedded, gray, finely to medium- brownish-gray to light olive- crystalline; contains scat­ gray, finely to medium- tered sand grains ...... 2 crystalline ...... 5 Sandstone, medium-bedded, Dolomite, medium-bedded, light-gray to white, dolo­ medium-gray, finely to mitic, quartzitic, fine- to medium crystalline ...... 5 medium-grained; contains Dolomite, medium-bedded, thin dolomite stringers ...... 2 brownish-gray to light .Dolomite, medium-bedded, brownish-gray, finely to light olive-gray, finely to medium-crystalline; lower medium-crystalline; c'on- 4 inches sandy to very tains scattered sand sandy...... 5 grains ...... 1 Sandstone, medium-bedded, Sandstone, medium-bedded, very light gray to white, light-gray to white, dolomitic, fine- to medium-grained; quartzitic, fine- to medium- lower 2 inches is grained ...... 2 dolomitic ...... 5 Dolomite, medium-bedded, Dolomite, medium- to brownish-gray to light thick-bedded, medium brownish-gray, sandy, finely dark gray to brownish- to medium-crystalline; sand gray, finely granular, content increases finely to medium - upward ...... 5 crystalline...... 4 Sandstone, medium-bedded, Sandstone, thin- to brownish-gray to white, medium-bedded, white, dolomitic, fine- to medium- dolomitic, medium- grained ...... 1 grained ...... 2

38 Ft in Ft in Ordovician rocks Continued Ordovician rocks Continued Everton formation Continued Everton formation Continued Dolomite, very thin to thin- Dolomite, thin- to medium- bedded, light olive -gray to bedded, medium-gray to light-gray, finely granular light olive-gray, sandy, to finely crystalline...... 2 7 finely granular to finely Dolomite, medium-bedded, crystalline ...... 4 0 dark-gray to brownish - Sandstone, medium-bedded, gray, finely granular to light-gray to yellowish- finely crystalline ...... 4 1 gray, dolomitic, fine- to Dolomite, medium-bedded, medium-grained ...... 8 medium dark gray to Dolomite, thin- to medium- brownish-gray, very finely bedded, light-gray and light granular to finely brownish-gray, very finely crystallina...... 5 0 granular to finely Dolomite, m edium - crystalline...... 3 2 bedded, medium -gray Dolomite, medium- to thick- to brownish-gray, sandy, bedded, light-gray to brownish- finely to m edium - gray, very finely granular crystalline ...... 1 8 to finely crystalline; sandy Dolomite, medium-bedded, in lower 18 inches...... 4 0 medium-gray to brownish- Dolomite, medium-bedded, gray, finely to medium- light-gray and light brownish- " crystalline ...... 3 8 gray, finely to medium- Covered interval...... 6 6 crystalline; sandy in lower Dolomite, platy, light-gray to 18 inches ...... 5 0 light brownish-gray, finely Sandstone, medium-bedded, granular to finely white, quartzitic, fine- to crystalline ...... 1 5 medium-grained; dolomitic Sandstone, platy to thin- in the upper 4 inches...... 10 bedded, white, dolomitic, Dolomite, medium-bedded, medium-grained ...... 6 light-gray (orange-mottled), Dolomite, platy to medium- sandy, dense to finely crystal­ bedded, light-gray to light line; sand content decreases brownish-gray, sandy, finely upward ...... 4 7 granular to finely Dolomite, medium- to thick- crystalline...... 1 3 bedded, orange-gray mottled Dolomite, medium- to thick- light-gray and light olive-gray, bedded, medium- to dark- very finely granular to finely gray, very finely granular crystalline ...... 3 2 to finely crystalline; 6-inch Dolomite, medium- to thick- sandy dolomite bed near middle bedded, light-gray to light olive - of unit...... 4 1 gray, dense to finely Dolomite, medium- to crystalline...... 5 0 thick-bedded, brownish- Base of section 65 feet above river level. ______gray, finely 'to medium- crystalline...... 5 0 398 0

LITERATURE CITED Adams, G. I., and Ulrich, E. O., 1905, U. S. Geol. Maher, J. C., and Lantz, R. J., 1952, Described Survey Geol. Atlas, Fayetteville folio (no. 119). .sections and correlation of Paleozoic rocks at Gilbert, Croneis, Carey, 1930, Geology of the Arkansas Carver, and Marshall, Ark.: U. S. Geol. Survey Paleozoic area: Arkansas Geol. Survey, Bull. 3, Circ.160. p. 26-28. ______1953, Geology of the Gilbert area, Giles, Albert, W., 1930, St. Peter and older Ordovician Searcy County, Ark.: U. S. Geol. Survey sandstones of northern Arkansas: Arkansas Geol. OM 132. Survey, Bull. 4, p. 5, 10. Owen, D. Dv 1847, Preliminary report of the Lantz, R. J., 1950, Geological formations penetrated geological survey of Wisconsin and Iowa: 30th Cong., by the Arkansas-Louisiana Gas Company No. 1 1st sess., Sen. Ex. Doc. 2. Barton well on the Cecil anticline, Franklin County, Purdue, A. H., and Miser, H. D., 1916, U. S. Geol. Arkansas: Arkansas Res. and Devel. Comm., Survey Geol. Atlas, Eureka Springs-Harrison Div. Geology, Bull. 18. folio (no. 202). McKnight, E. T., 1935, Zinc and lead deposits of Ulrich, E. O., 1911, Revision of the Paleozoic systems: northern Arkansas: U. S. Geol. Survey Bull. 853. Geol. Soc. AmericaBulL, v. 22, p. 281-680.

IHT.-tW. SEC., WASH., D.C. U61S(J 39