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Home , Arkansas, Atoka Formation, Fernvale Limestone, Moorefield Formation, Oklahoma

Geology of the Greenwood Quadrangle -

GEOLOGICAL SURVEY PROFESSIONAL PAPER 536-A

Prepared in cooperation with the Arkansas Geological Commission

Geology of the Green-wood Quadrangle Arkansas-Oklahoma

By BOYD R. HALEY and THOMAS A. HENDRICKS

GEOLOGY OF THE ARKANSAS COAL FIELD

GEOLOGICAL SURVEY PROFESSIONAL PAPER 536-A

Prepared in cooperation with the Arkansas Geological Commission

UNITED STATES GOVERNMENT PRINTING OFFICE, : 1968 DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY William T. Pecora, Director

For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 CONTENTS

Page Page Abstract______A1 Stratigraphy-Continued Introduction ______1 Devonian and Systems, Chattanooga Shale______StratigraphY------2 A6 Cambrian System______-----______2 Mississippian System ______-- __ --_ 6 Ordovician System______3 Post-Chattanooga pre-Pitkin formations ______6 Van Buren Formation and Gasconade Dolomite Pitkin ______------__ 7 undifferentiated ______3 Pennsylvanian System______7 Roubidoux Formation______3 Morrow Series ______7 Jefferson City Dolomite ______3 Atoka Series, ______7 Cotter Dolomite______3 Des Moines Series, Krebs Group ______7 Powell Dolomite______------______3 Quaternary System ___ ------__ ------9 Terrace deposits- ______-- ___ - Everton Formation ______3 9 9 St. Peter Sandstone ______------_ 3 StructureAlluvium------______9 Joachim Dolomite ______3 Economic geology ______---_-___ ------10 Plattin Limestone ______------______6 ______Coal------10 6 Oil and gas ______- ______- ___ ------12 Cason Shale______6 Building stone______--- __ -----_------12 Silurian and Devonian Systems, St. Clair Limestone Road metal ______--______--____ _ 15 and undifferentiated rocks _____ ------______6 Gravel, sand, and claY------15 Devonian System, Penters ______6 References cited ______- __ - ___ ---_- __ ------15

ILLUSTRATIONS

[Plates are in pocket] PLATE 1. Geologic map of Greenwood quadrangle. 2. Stratigraphic sections in Greenwood quadrangle. 3. Structure-contour, coal-bed, and gas-field-map of Greenwood quadrangle. 4. Structural sections in Greenwood quadrangle. Page FIGURE 1. Index map of Arkansas------A2 2. Diagram showing thickness of Atoka Formation in the Greenwood~quadrangle and vicinity______8

TABLES

Page TABLE 1. Stratigraphic nomenclature in or near the Greenwood quadrangle______--_------A4 2. Selected coal thickness measurements in the Greenwood quadrangle ______-_-_------10 3. Estimated remaining reserves of coal in the Lower Hartshorne coal bed in the Arkansas part of the Greenwood quadrangle------11 4. Estimated original, remaining, and recoverable reserves of coal in the Arkansas part of the Greenwood quadrangle_ 11 5. Estimated original reserves of coal in the Upper Hartshorne coal bed in the Arkansas part of the Greenwood quadrangle------12 6. Description of selected wells drilled in or near the Greenwood quadrangle as of 1, 1964______13 III

GEOLOGY OF THE ARKANSAS VALLEY COAL FIELD

GEOLOGY OF THE GREENWOOD QUADRANGLE, ARKANSAS-OKLAHOMA

By BoYD R. HALEY and THOMAS A. HENDRICKS

ABSTRACT clay; and ( 6) provide data on the and relations The Greenwood quadrangle is in west- and of the rock formations exposed at the surface and pres­ east-, between lats 35°00' and 35°15' N. and ent in the subsurface. longs 94°15' and 94°30' W. It comprises an of about 184 This report is also published, under separate cover, as square miles in Sebastian , Ark., and about 60 square Arkansas Geological Commission Information Circular miles in Le-Flore County, Okla. 20-F. Sedimentary rocks of Middle Pennsylvanian age and uncon­ solidated sediments of Quaternary age are exposed at the sur­ The Greenwood quadrangle is between lats 35°00' face, and sedimentary rocks of Late Cambrain to Middle and 35°15' N. and longs 94°15' and 94°30' W. It covers Pennsylvanian age have been penetrated by wells drilled in or an area of approximately 184 square miles in Sebastian near the quadrangle. County, Ark., and about 60 square miles in Le Flore The rocks in the quadrangle have been folded into eastward­ County, Okla. (Seefig.l.) trending synclines and anticlines ~and broken by normal and reverse faults. Displacement along one of the normal faults Generalized geologic reports pertaining in part to the is proba'bly 1,100 feet, 1and displacement along the reverse Greenwood quadrangle were made by Croneis (1930) faults is estimated to aggregate more than 12,800 feet. Struc­ and Haley ( 1960) for the Arkansas part, and by Drake tural relief as measured on the base of the Hartshorne Sand­ stone is more than 10,800 feet. ( 1897), Taff and Adams ( 1900), Taff ( 1905), Snider The Atoka, McAlester, and Savanna Formations contain coal (1914), and (1914) for the Oklahoma part. beds. The Lower Hartshorne coal bed near the base of the Detailed geologic reports pertaining in part to the McAlester Formation is the thickest, the most widespread, and Greenwood quadrangle were made by Collier (1907) the most important economically. The Upper Hartshorne coal bed, the only other economically important co,al bed, is present and Hendricks and Parks (1937, 1950) for the Arkansas only in the southern part of the quadrangle. part, and by Hendricks ( 1939) and Knechtel ( 1949) for Commercial quantities of have been produced the Oklahoma part. from the lower part of the McAlester Formation, the Hartshorne The stratigraphic nomenclature and boundaries es­ Sandstone, the Atoka Formation, the Morrow Series, the Penters Chert, and the St. Clair Limestone. tablished by Hendricks and Parks ( 1950) for the Building stone has been obtained from the Atoka, Hartshorne, Pennsylvanian rocks in the Fort Smith district, Arkan­ and McAlester Formations. Road metal has been obtained from sas, are used in this report with modifications. Mere­ these formations, the Savanna Formation, and the gravelly part wether and Haley (1961) adopted Miser's (19·54) of alluvial deposits. terminology of McAlester, Savanna, and Boggy Forma­ INTRODUCTION tions, and Oakes' ( 1953) classification of the Kr~bs This report on the geology of the Greenwood quad­ Group, which includes the Hartshorne Sandstone and rangle is one of a series of reports being prepared by the the McAlester, Savanna, and Boggy Formations. Haley U.S. Geological Survey in cooperation with the Arkan­ (1961) moved the contact between the Savanna Forma­ sas Geological Commission. Its purpose is to ( 1) pro­ tion and the overlying Boggy Formation stratigraph­ vide a geologic map of the quadrangle on a modern ically upward from that selected by most earlier topographic base; (2) show the extent and thickness of workers, thereby conforming to Miser's (1954) interpre­ all coal beds; ( 3) present estimates of coal reserve; ( 4) tation. The pre-Pennsylvanian nomenclature used in provide geologic data and interpretations pertinent to this report conforms to that used in Arkansas. Table 1 the location of natural gas and petroleum; ( 5) provide compares the nomenclature used in the area of this information about building stone, gravel, sand, and report with that used in nearby areas. A1 A2 GEOLOGY OF THE ARKANSAiS VALLEY COAL FIELD

gzo------r='\___ _9lo

FULTON I \ ....--' .. ---~ ~~

IZARD ! SHARP i

I ------1I I I l -----r _ __L_~ I l

\ CRITTEND£~ ___ __,__1 I' .... )

---, ------j t ~~ i 1 l LEE r··.)~\~ .._ _j MONROE., ----{'-"'-:\ ~~s ,-~, ) ~ -q_'L+J ""l. I ~ I 1'"\_ PHILLIPS ) I ... c-., 0 I ARKANSAS /''::1~..., ~ EXPLANATION ('-' ._,-'l. (-::;:.:] ....~ 00 '),' "ii Area of this report I ..., \ I ~ ,L__ T--; iiEMPSTEAD I Area of other reports ~ I I OUACHITA ../ t---- in• this series r<~\ I I Ss CALHOUN \ Boundary of physiographic r--~ - , ~--- ) BRADLEY province 1 ~ ~ 7 --r--t_ -----..... I MILLER .. f-< I ~ .r~---~ s Boundary of physiographic : l ~ I COLUMBIA ASHLEY sectionl · I ~~ j UNION '2) 330.1 _]____ L ____ _ 1 Physiographic divisions from Fennemanand Johnson (1946) 0 25 50 MILES

FmuRE 1.-Location of report area ( F, a) andareas of other published chapters of Arkansas Geological Commission Information Circular 20 or of U.S. Geological Survey Professional Paper 536: A, quadrangle (Merewe·ther and Haley, 1961); B, Paris quadrangle (Haley, 1961); 0, Barber quadrangle (Haley, 1966); E, Knoxville quadrangle (Mere­ wether, 1967); G and b, Scranton and New Blaine quadrangles (Haley, 1968); and H and c, Coal Hill, Hartman, and Clarksville quadrangles (Merewether and Haley, 1968).

STRATIGRAPHY Co. Coal and Mining Co. 1 (well 2, pl. 2), which was described by Haley and Frezon (1965), and Rocks o:f Cambrian to Middle Pennsylvanian and o:f the Nichols Exploration Corp. Gann 1 (well12, pl. 2), Quaternary age are exposed or have been penetrated which has been described by Haley ( 1966) . by wells drilled in or near the quadrangle. The areal extent o:f some o:f these rocks is shown on plate 1, and CAMBRIAN SYSTEM the lithology o:f these rocks, except :for those o:f quater­ nary age, is shown graphically on plate 2. All but two Rocks o:f the Cambrian System were penetrated in the o:f the stratigraphic sections shown on plate 2 are de­ Shell Oil Co. Western Coal and Mining Co. 1 (well 2). scribed in detail. These two sections are the Shell Oil Haley and Frezon (1965) were uncertain whether these GEOLOGY OF THE GREENWOOD QUADRANOLE, ARKANSAS-OKLAHOMA A3 rocks correlate with Cambrian rocks exposed to the urn-dark-gray granular to medium-crystalline dolomite north in or to the southwest in Oklahoma. containing fine to coarse sand and white, gray, They stated that "the lower 20 feet of this well pene­ or pink chert. Thin beds of dark-gray or grayish-black trated rocks possibly equivalent to the upper part of the chert are scattered throughout the formation. Derby-Doerun" in Missouri "and the Butterly Dolo­ mite" in Oklahoma. "If this is so, there may be several COTTER DOLOMITE hundred feet of sedimentary rocks between the total The Cotter Dolomite is 365 feet thick where pene­ depth of this well and the Precambrian ." trated by well 2. It is light- to dark-gray granular to The above well penetrated 416 feet (depth of 10,508- 10,924 ft) of very light to medium-gray granular to finely crystalline dolomite containing light-gray or pink coarsely crystalline dolomite containing fine to coarse chert and some fine to coarse quartz sand. In the lower quartz sand and white to medium-light-gray opaque 60 feet of the formation some of the chert is oolitic and chert. Thin beds of sandstone are in the intervals 10,508- contains fine to medium quartz sand. A thin bed of 10,558 feet and 10,883-10,905 feet. The rock in the inter­ greenish-gray pyritic shale is at the top of the formation. val10,905-10,924 feet consists of a dark-gray dolomitic POWELL DOLOMITE silt-size quartz matrix containing very fine to medium quartz sand, very fine angular to subrounded crystals The Powell Dolomite is 227 feet thick where pene­ of feldspar, and abundant coarse crystals of light- to trated by well 2. It is a light- to dark-gray granular dark-gray and pink dolomite. dolomite containing widely scattered pyrite, some gray­ ish-black chert, and some olive-gray translucent chert. ORDOVICIAN SYSTEM

VAN BUREN FORMATION AND GASCONADE DOLOMITE EVERTON FORMATION UNDIFFERENTIATED The Everton Formation is 503 feet thick where pene­ The Van Buren Formation and Gasconade Dolomite trated by well 2 and probably at least 114 feet thick undifferentiated is 483 feet thick where penetrated by where penetrated by the Midwest Oil Corp. Floyd Mor­ the Shell Oil Co. Western Coal and Mining Co. (well ris 1 (well 9). The formation consists of medium- to 2). The basal part of this unit is the Gunter Sandstone dark-gray granular to finely crystalline dolomite con­ Member of the Van Buren Formation. The Gunter taining fine to medium quartz sand and white to very consists of 143 feet of fine to very coarse grained quartz light gray ,fine- to coarse-grained sandstone. Some dark­ sandstone. Thin beds of very light to medium-light­ gray shale is in the upper and lower parts of the forma­ gray granular to medium-crystalline dolomite are in the lower 50 feet of the Gunter. The remainder of the Van tion, and some medium-dark-gray and olive-gray dense Buren and Gasconade unit is very light to dark-gray to very finely crystalline limestone is in the middle of granular to coarsely crystalline dolomite with scattered the formation. fine to coarse quartz sand and abundant white to light­ ST. PETER SANDSTONE gray or pink chert. Much of the white chert contains fine to medium dolomite rhombs. A few thin beds of The St. Peter Sandstone is 72 feet thick in well2 and dark-gray shale are in the upper 15 feet of the unit. 81 feet thick, as estimated from the electrical log, in well 9. The formation is white to very light gray sub­ ROUBIDOUX FORMATION rounded fine- to coarse-grained sandstone. The Roubidoux Formation is 230 feet thick where penetrated by well 2. It consists of very light to me­ JOACHIM DOLOMITE dium-light-gray granular to coarsely crystalline dolo­ The Joachim Dolomite is 95 feet thick in well2 and is mite containing abundant fine to coarse quartz sand and estimated to be 83 feet thick in well 9 ; 141 feet of the white to medium-gray, olive-gray, or pink sandy and formation was penetrated by Mobil Oil Co. W. K. oolitic chert. Some chert is very light gray (milky) Veazey 1 (well18). The formation is mostly medium­ and some is medium gray (smoky). White chert con­ to dark-gray granular to very finely crystalline dolomite taining very coarse crystals of dolomite is in the lower containing fine ,to coarse quartz sand. Some beds of 75 feet of the formation. white to light-gray fine- to medium -grained sandstone JEFFERSON CITY DOLOMITE are present. The upper 45 feet of the formation in the The Jefferson City Dolomite is 465 feet thick where Veazey well (well18) is light- to dark-gray very finely penetrated by well2. It is predominantly light- to medi- crystalline dolomite that is free of sand. TABLE 1.-Stratigraphic nomenclature in or near the Greenwood quadrangle ~ Th" t Generalized northeast and East-central Oklahoma East-central Oklahoma West-central Arkansas IS repor east-central Oklahoma (Hendricks, 1939) (Knechtel, 1949) (Hendricks and Parks, 1950)

Boggy Formation Boggy Formation Boggy Shale Boggy Formation Boggy Shale 00 00 ·~ 0. .~ 0. J.l S Savanna Formation ~ g Savanna Formation Savanna Sandstone Savanna Formation Savanna Sandstone ~ ~ ~ ~ .s 00 .s 15 f------1 . ~ iJ ~ ~ McAlester Formation McAlester Shale McAlester Formation oo ~ McAlester Formation oo ~ oo McAlester Shale ~ ~ Upper Upper Upper 00 ·~ Hartshorne Hartshorne Hartshorne 5 J.l Sandstone Sandstone Sandstone ~ l=l 1------Z Hartshorne Sandstone Z Lower Lower z ~ Lower ~ .~ Hartshorne Sandstone < < ;::: ·;: z ~ 0 z z z J.l 0 ~ t:zj ~ ~ Zone W ~ ~ oo .~ ~ 00 § ~ b ...... :1 ..... ::> s...... :1 Q) < l=l ~ ~ ~ • :>< ~ • ~ J.l Atoka Formation ~ ·§ Atoka Formatton o ~ Atoka Formation 0 ~ ~ Atoka Formation ~ Cl! Atoka Formation ~ § z ~ P-1 ~ z .!:d z ~ ~ -a .... ·;:: 0 ~ ~ Zone P ~ < ~ 1 ~ A 1-:rj ~ ~ l---+------4o ~ Q) . P-1 Kessler(?) Limestone Bl d Kessler Limestone ~ ~ Bl0 Yd Member ~ oy Member ·~ Formation ·~ Formation Brentwood Limestone ~ 00 00 ~~ ~ ~ ~ Prairie Grove t Prairie Grove Ul~ o . Member o . . Member ~ Hale Formation ~ Hale FormatiOn ~ Cane Hill Cane Hill Member Member ~ ~ Pitkin Limestone Pitkin Limestone l;lj ~ i C':l s.. ~ 0 Q) 00 ~ ~ ~ 0 l:l:l ; . • Hindsville Limestone z l=l Pre-P.1tkm z ; < Cl! < f----+------~ ~ ~ post-Chattanooga ~ ~ ~ 00 ~ . 00 S Q) Moorefield Formation oo H formatiOns oo ~ ~ ~ .... Q) f------~ ~ ~ ~ ~ ~~ ~ Q) Cl! ~ ~CI!

.!:d .!:d 8 8 .d Q) 'f Q) ~ ~ Q) ~ "8 'g Chattanooga Shale ~ g r-? 1---- r-?-- Upper z~~~------~ z< s.. ;:S Middle z o Q) Penters Chert z -?-- Sallisaw Formation ~ j! ~~ ~ 1 ___ Fri•co J.im•s'::_ w 1-' w I -l ~?- 0 z CJl St. Clair Limestone < St. Clair Limestone I I~ and undifferentiated ~ and undifferentiated 0:> ~ ::;:J ::;:J rocks rocks ...:l ::l w 00. rt-:1 ... Cason Shale ... Sylvan Shale 0 (I) (I) tr.l p. p. p. p. 0 ;::l ;::l b Fernvale Limestone Fernvale Limestone 0 ""-1 0 Plattin Limestone Fite Limestone l2j t-3 z ~ (I) Joachim Dolomite < tzj ;:a u '"0 ~ 0 :g 0> ~ St. Peter Sandstone ~ McLish Formation tzj ~ tzj 0 Tyner Formation Everton Formation 0~ z Burgen Sandstone 0 < t:;j u s:: Powell Dolomite .... ~ Powell Dolomite >0 (I) Col ~ ~ ·:;: ~ ~ ,...0 :q; 0 t:;j 0 Cotter Dolomite Cotter Dolomite ~ 0 ~ ~ Jefferson City Dolomite tzj ... > (I) ~ ~ Roubidoux Formation 0 ...:I ~ Gasconade Dolomite r:Jl U2> and I Van ~Buren Formation 0 undifferentiated ~

Gunter Sandstone ~ ~ Member > • z

L__ ~ ~---~

c.n> A6 GEOLOGY OF THE ARKANSAS VALLEY COAL FIELD

PLATTIN LIMESTONE dominantly very light gray translucent chert or very The Plattin Limestone is 48 feet thick in well 2, 130 light to 1nedium-gray opaque chert with a few thin feet thick in well 9, and 125 feet thick in well 18. It is beds of very light to 1nedium-gray granular limestone. predominantly mecllium- to dark-gray dense to granular The chert is limy, dolmitic, and pyritic. The formation limestone containing abundant fine to coarse crystals of is missing in well 18 because of normal faulting or pre-Chattanooga post-Penters erosion. dolom~te and calcite. Some beds of medium-light-gray and ohve-gray very finely crystalline limy dolomite are DEVONIAN AND MISSISSIPPIAN SYSTEMS, in the lower part of the formation. CHATTANOOGA SHALE FERNVALE LIMESTONE The Chattanooga Shale is 38 feet thick in well 2, The Fernvale Limestone is 45 feet thick in well 2 4 7 91 feet thick in well 9, and 35 feet thick in well 18. It feet thick in well 9, and 48 feet thick in well 18. I~ is is pyritic dark-gray to grayish-black shale. light- to medium-gray granular to coarsely crystalline MISSISSIPPIAN SYSTEM limestone. Crystals of dolomite and pink calcite are rare to COnlmOn. POST-CHATTANOOGA PRE-PITKIN FORMATIONS CASON SHALE Rock units, or their equivalents, in this interval else­ The Cason Shale is 15 feet thick in well 2 25 feet where in the Arkansas Valley and Ozark Mountains are, thick in well 9, and 22 feet thick in well18. Th~ forma­ in ascending order, the Boone Formation, the Moorefield tion is greenish-gray a11d dark-gray dolomitic shale that Formation, the Ruddell Shale, the , contains finely crystalline pyrite in some parts. and the Fayetteville Shale. This sequence of rocks is 368 feet thick in well2, 257 feet thick in well 9, and 410 feet SILURIAN AND DEVONIAN SYSTEMS, ST. CLAIR thick in well18. The rocks consist of dark-gray granular LIMESTONE AND UNDIFFERENTIATED ROCKS to very finely crystalline silty limestone and dark-gray The St. Clair Limestone of this report is the St. Clair to grayish-black nonsilty to very silty nonlimy to very equivalent of Haley and Frezon (1965). It is 115 feet limy shale in wells 2 and 9, and of dark-gray shale, some thick in well 2, 145 feet thick in well 9, and 52 feet thick of which is silty, some medium-gray limy siltstone, some clark-gray to grayish-black shale, and some medium- to in wel~ 18 .. It grades from very light gray granular limy dark-gray argillaceous granular silty limestone in well dolo~rnte 1n well 2 through interbedded very light to 18. The Boone Formation, which consists of lilnestone mechu~-gray ~ranular to very finely crystalline limy dolomite and hght-gray granular to medium-crystalline and chert north of the Greenwood quadrangle, cannot be dolomitic limestone in well 9 to medium-gray granular recognized in wells 2, 9, and 18, but rocks equivalent to to finely crystalline dolomitic limestone in well 18. In the Boone may be in these wells. The Ruddell Shale can­ wells 2 and 9 the St. Clair is overlain by the Penters not be identified in wells 2, 9, and 18, but it or its Chert of Devonian age, and the Penters is overlain by equivalent may be present. In areas where the Bates­ the Chattanooga Shale of Devonian and Mississippian Yi~le Sandstone is missing or unidentifiable, as it is in tlus quadrangle, the ::Moorefield Formation is distin­ age. I~1 well18 the St. Clair is overlain by Chattanooga. In tlus well, about 100 feet of St. Clair and all of the guished lithologically from the Fayetteville Shale by Penters is missing because of normal faultin

ATOKA SERIES, ATOKA FORMATION Hart8horne Sandstone.-The Hartshorne Sandstone unconformably overlies the Atoka Forn1ation. The con­ The Atoka Formation composes the Atoka Series in tact is well exposed in the roadcut near Hackett and in Arkansas and Oklahoma. It is 6,390 :feet thick in well2, a roadcut south of Huntington along U.S. Highway 71 about 7,943 :feet thick in well 9, and10,600 :feet thick in near the center o:f NE1;4SvV% sec. 25, T. 5 N., R. 31 vV. well18. The lower 600 feet of the Atoka is missing :from The Hartshorne Sandstone ranges in thickness from 10 well18 because of a normal :fault that was active during to 210 feet in the Greenwood quadrangle. It is pre­ early and middle Atoka deposition. The Atoka ranges dominantly very light to medium-gray very fine to in thickness :frmn about 5,500 feet in the northwestern fine-grained sandstone that is slightly silty or silty in part o:f the quadrangle (fig. 2) to about 14,750 feet in part. Thick beds of shale and and siltstone in the :for­ the southeastern part. The Atoka thickens soutlnyard; mation crop out along the south side o:f the Backbone the middle and lower parts thicken more than the upper anticline. (See pl. 1.) The sandstone is in beds of the part. The :fault plane cut by well18 does not reach the ehannel type throughout much o:f the Greenwood quad­ surface in the Greenwood quadrangle. The a1nount o:f movement (about 1,100 :ft) along this :fault plane is rangle. The ehannel-type sandstone is 'Yell exposed in thought to be compensated by an equal amount of c?n­ the roadcut along Arkansas State Highway 45 near the current thickening within the Atoka on the south side NW cor. NE%NE~ sec. 21, T. 6 N., R. 32 W., and in of the fault. However, if the fault :formed in the late the quarry near the center of NE%SW1;4 sec. 35, T. 7 N., early or middle Atoka time, the upthrown side may have R. 31 W. At the quarry about 2 feet of one channel is been eroded before the deposition o:f younger Atoka filled with angular :fragments of clark-gray shale as beds. Most, i:f not all, o:f this thickening could have large as 3 by 15 by 20 inches and ironstone concretimis occurred in the middle part of the :formation. The Atoka as large as 3 by 6 by 10 inches. AS GEOLOGY OF THE ARKANBAS VALLEY COAL FIELD

94°00'

35°15'

35°00'

0 5 10 15 MILES ~:~_L ______L ______~

FIGURE 2.-Thickness of Atoka :E'ormation in the Greenwood quadrangle (shaded) and vicinity, Arkansas and Oklahoma. Interval is 1,000 feet. Thickness lines from Haley ( 1961, fig. 6; 1966, fig. 8) with modifications based on subsequent information.

M cA. lester Formation.-The McAlester Formation R. 31 "\V. (pl. 1), so Hendricks and Parks and the au­ conformably overlies the Hartshorne Sandstone. It is thors of this report used the top of the first sandstone 1,458 feet thick in the Veazey well (No. 18). Hendricks below the Lower Hartshorne coal bed as the base of the ( 1939) estimated thicknesses of 1,850 feet at one loca-. ~{cAl ester. tion (pl. 33) and 2,000 + feet at another location (fig. Savanna Formation.-The Savanna Formation over­ 15) on the basis of scattered surface measuren1ents lies the McAlester with a locally unconformable con­ across many concealed intervals. The McAlester Forma­ tact. However, at places the contact is gradational and tion is dark-gray to grayish-black shale with minor the McAlester and Savanna intertongue. The Savanna amounts of medium-gray siltstone and light- to medium­ Formation is 1,300 feet thick in the Greenwood quad­ gray very silty very fine grained sandstone to light-gray rangle. It is medium- to dark-gray shale with smaller very fine grained sandstone. The McAlester has at least amounts of light- to medium-gray siltstone and light­ four coal beds; the most economically in1portant and to medium-gray very silty very fine grained sandstone. widespread is the Lower Hartshorne coal bed near Sediment-flow features are common in the sandstone. the base of the formation. Excellent sediment-flow fea­ Boggy Formation.-The Boggy Formation overlies turas are exposed in NW14NW14 sec. 2, T. 4 N., R. 32 vV. the Savanna conformably. It is represented by 25 feet The McAlester Formation of this report contains rocks considered by Hendricks and Parks (1937) to be equiva­ of very light gray very fine to medium-grained friable lent of the upper part of the Hartshorne Sandstone in quartzose sandstone on Sugarloaf Mountain. Hendricks Oklahoma. These rocks are the shale below the Hart­ (1939, p. 272) reported as much as 4,000 feet of Boggy shorne coal, the Hartshorne coal, the shale above the in nearby areas, but ~fiser ( 1954) revised the base of the coal, and the lenticular sandstone above the shale. These Boggy and included beds in the Savanna that Hendricks rocks cannot be mapped northeast of sec. 24, T. 6 N., placed in the Boggy. GEOLOGY OF THE GRE·ENWOOD QUADRANGLE, ARKANSAS-OKLAHOMA A9

QUATERNARY SYSTEM The faulted Backbone anticline extends across the TERRACE DEPOSITS northern part of the quadrangle; the Washbur~ anti­ cline extends westward into the northeastern part of Alluvial n1aterial deposited by the the quarangle; the Midland anticline extends eastward forms one terrace in the northwest corner of the Green­ nearly across the quadrangle; and the Hartford anti­ wood quadrangle, and alluvial material deposited by cline extends across the southeast corner of the quad­ local streams forms one or two terraces everywhere in rangle. The Backbone anticline has been broken by the quadrangle. Terrace deposits along the Arkansas reverse faulting throughout most of its extent in the River consist of clay, silt, and sand, some of which is of Greenwood quadrangle. The Washburn anticline has local origin; pebbles and cobbles of shale and sandstone been broken by reverse faulting in the extreme eastern of local origin; and pebbles of quartz and chert of dis­ part of the quadrangle. The south limbs of the unfaulted tant origin. The terrace deposits formed by local streams Midland and Hartford anticlines are steeper than the consist of clay, silt, and sand, and pebbles, cobbles, and north limbs, whereas the north limbs of the Backbone boulders of shale, siltstone, and sandstone of local and Washburn anticlines are steeper than the south origin. Reworked material from the river terrace is in limbs. some of the stream terraces. The river-terrace gravel and The normal faults at the surface in the west-central the uppermost stream-terrace gravel are thought to be part of the quadrangle (pls. 1, 3) have displacements equivalent to the Gerty Sand of Pleistocene age. of less than 40 feet. One of the faults dips 46° S. where ALLUVIUM exposed in sec. 28, T. 8 N., R. 27 E., but it dips an esti­ Alluvium has been deposited along most of the mated 60° S. in sec. 5, T. 5 N., R. 32 W. A normal fault streams in the Greenwood quadrangle. It consists of with a displacement of about 1,100 feet is at a depth of clay, silt, and sand, pebbles of shale, siltstone, and sand­ 12,815 feet in the Veazey well (well18). This fault does stone, and, in some places, cobbles and boulders of shale, not extend to the surface, and how much of the Atoka, siltstone, and sandstone. Some of the alluvium contains or younger formations, is cut by this fault is unknown. reworked material from the river terrace. The strike and the direction and amount of dip of the fault plane are unknown, but elsewhere in Arkansas, STRUCTURE normal faults of this magnitude generally strike east The Greenwood quadrangle is in the Arkansas Valley and dip southward at angles of 50°-60°. (See section section of the Ouachita province (fig. 1). The rocks in B-B', pl. 4.) Three normal faults were discovered by the quadrangle have been folded into east-trending anti­ coal miners in the northeastern part of the quadrangle. clines and synclines. Two anticlines have been broken The direction of dip of the fault plane was recorded for by reverse faulting and one syncline has been broken two of these faults, and a dip of 63° N. was recorded for in one place by normal faulting. (See pls. 1, 3.) Struc­ the fault in sec. 31, T. 7 N., R. 32 W. The amount of dis­ tural relief on the base of the Hartshorne Sandstone is placement along these faults is unknown but probably is more than 10,800 feet as measured from the trough of less than15 feet. the Cavanal syncline to the projected crest of the Back­ The reverse faults in and near the Greenwood quad­ bone anticline. (See pls. 3, 4.) rangle are in zones that may contain as many as 12 The closure of the anticlines is thought to diminish reverse faults and be as much as 2 miles wide. (See pl. 1, with depth partly because of the southward-thickening see also Haley, 1966, pl. 1.) Movement along the reverse of the Atoka Formation and partly because folds in faults probably represents a relief of the pressure that near-surface rocks are represented by reverse faults at caused the folding of the Backbone and Washburn depth that cut the bedding of the rocks at an angle that anticlines. decreases downward until the movement becomes bed­ A small segment of one fault in the Washburn fault ding-plane slippage. zone is in sec. 24, T. 6 N., R. 31 W. The movement along The south limb of the Central syncline extends across the Washburn fault zone decreases from 5,000 + feet the northern part of the quadrangle; the Jenny Lind as measured on zone PinT. 6 N., R. 27 W. (Haley, 1966, syncline extends across the extreme northeast corner of p. 11), to zero on the west end of the fault in the Green­ the quadrangle; the Greenwood syncline extends across wood quadrangle. the north-central part of the quadrangle; the Cavanal The Backbone fault zone, which extends nearly syncline extends across the south-central part of the across the northern part of the Greenwood quadrangle, quadrangle; and a part of the north limb of the Poteau consists of two to five faults and is 300-4,000 feet wide. Mountain syncline extends across the southeast corner The fault planes of the major faults in the Backbone of the quadrangle. zone probably dip southward from angles near vertical AlO GEOLOGY OF THE ARKANS.AiS VALLEY COAL FIELD at the surface to less than 15 ° in the subsurface. Fault TABLE 2.-Selected coal thickness measurements in the Greenwood planes of the major faults are not exposed in the quad­ quadrangle [All measurements made in the Upper Hartshorne coal bed in the McAlester For­ rangle; however, they can be accurately mapped, and a mation, except as noted] dip of 75° can be estimated for the fault in NW% sec. 2, Depth Thickness T. 6 N., R. 31 W. The major fault planes have angular Approximate location of coal of coal relationships to the strata; these range from parallel to (feet) (inches) nearly 90° in the oversheet and from parallel to nearly Arkansas 180° in the undersheet, where the strata are overturned. T. 6 N., R. St W. The amount of movement along any one fault is un­ Center NEUSEU sec. 351 ______Outcrop 4 T.6N.,R.3S W. known, but the combined amount of movement along NW cor. sec. 4 58 2 2------T.6N.,R.31 W. all the faults, as estimated on the projected base of the SW cor. NEUNEU sec. 1------­ 13 12 NE cor. SEUNW!iNWU sec. 28------­ 59 14 Hartshorne Sandstone, exceeds 12,800 feet near the NW cor. SWUSWUNWU sec. 28------···-··· 64 16 SW cor. SEUSEUNWU sec. 28------·--·· 78 15 Arkansas-Oklahoma boundary. The apparent amount SEcor. NWUNWUSWU sec. 28------·--·····--·- 108 8 of movement along these fault planes and along the fault SE cor. NWUSWU sec. 28------···------­ 140 24 SE cor. NEUNEUNEUSWU sec. 28------67 18 zone decreases to zero at that place in the subsurface SW cor. SWU sec. 28------166 4 SE cor. SWUNWUSEUSWU sec. 28------­ 138 24 where the fault planes become parallel to bedding Center NWUSEUSWU sec. 28 •••. ------.• 102 15 planes of the encompassing rocks. Slickensided shale, SW cor. SEUSEUSWU sec. 28------­ 81 8 SE cor. NWUSEU sec. 28------· 37 18 siltstone, and sandstone, found along many of the major SW cor. SEUNEUSEU sec. 28------­ 23 22 SW cor. SEUSEUSEU sec. 31.------· 64 10 faults, are well exposed in the quarry in NE%SE% Center NEUNEUNEUNEU sec. 32------230 24 sec. 4, T. 6 N., R. 32 W. NW cor. NEUNWUNEUNEU sec.32------­ 238 24 Center NWUNE!iSWU sec. 32------­ 192 24 Center SEUNEUSWUSEU sec. 32------­ 80 10 The subsidiary reverse faults in the quadrangle have NE cor. NWUNEU sec. 33 ..------­ 50 30 smaller magnitude and less steeply dipping fault planes. SE cor. NWUNEU sec.33------· 12 24 SW cor. NWUSWUNEU sec. 33------­ 33 7 Fault planes of some of these faults are exposed in Center NE%NE%NWU sec. 33·------­ 128 18 NW cor. SWUSWUNW% sec. 33------­ 174 9 the following places: In a roadcut on Arkansas State NW cor. NWUSEMNWU sec. 33------­ 88 24 Highway 45 in the center of NE%SW% sec. 4, T. 6 N., SW cor. NEUNEUSEU sec. 33------33 7 R. 32 W., where the dip is 55° S. and the amount of T.oN.,R.SS W. NW cor. SW%SEU sec. 1L------­ 186 31 displacement is probably less than 10 feet; near the Center SEUSE% sec. 11------­ 148 52 Center sW~swu sec.12------·· 138 66 center of NWlA,SW% sec. 4, T. 6 N., R. 32 W., where Center NE%NEU sec. 14------·------·----­ 111 54 Center NWUNEU sec.14------­ 132 70 the dip is 10° S. and the amount of displacement could Center SWUNEU sec.14.------­ 126 33 Center SWUNWU sec.14------­ 192 39 be as much as 800 feet; and near the center of Center SEUSEUNEU sec. 21~------343 24 NE%NE14NW% sec. 2, T. 6 N., R. 32 W., where the dip Do •• _•••••••••••• _____ ------_-- ___ -_____ • ____ . --_. _-- _ 700 18 NW cor. SWUSWUSEUNEU sec. 28 '------79 6 is 35 ° S. and the amount of displacement could be as Do.2 ______• ______--•• ------•••• ---_------187 6 Do.z. ______•• _----- __ ------. 200 18 1nuch as 1,600 feet. Do.s ______---- ______------.• ---_------819 4 Do.a __ ------845 12 A north-dipping reverse fault is exposed in the road­ Do.s ______------••• -----_------1,200 12 Do. ______---___ ------.-----_--- 1,505 11 cut of U.S. Highway 71 in SE%SE%SE14 sec. 31, T. SW cor. SEUSWUNEU sec. 29 '------Outcrop 4 7 N., R. 31 W., where the dip of the fault plane ranges T.,IN.,R.SS W. from 5°-15°. The amount of southward movement along 900ft from north line, 2,300ft from west line sec. 2 •------24 9 1,950 ft from south line, 400ft from west line sec. 5•------408 12 this fault is unknown but is probably small. Do.s_ ------780 12 Do ••. ------______------1,182 5 2,650 ft from north line 1 700ft from west line sec. 6 a______Outcrop 4 ECONOMIC GEOLOGY SEcor. SWUSWUNEU sec. 7 a______241 4 Do.s ______------626 3 Do .. ______----- __ ------1,058 COAL 9 NE cor. SEUSEUNW.% sec. 8 2------303 2 Do. _. ______------__ •. _____ • ______• _-.--- 727 8 The Atoka, McAlester, and Savanna Formations con­ Center sec. 9..•• ___ ------_____ ----- ______44 18 SW cor. NWUNWUSEUSE% sec. 9------­ 26 4 tain coal beds. The Lower Hartshorne coal bed has been SW cor. SWUNWUSEUSEU sec. 9------45 6 mined :vather extensively in the area, and the Upper Center NWUSW%SEUSEU sec. 9------­ 38 6 Center SWUSWUSE%SE% sec. 9------­ 34 8 Hartshorne and the Stigler coal beds have been mined NE cor. SE%NEUNW% sec.16------­ 31 15 Center NWUNEMSWM sec.16------­ 231 18 locally. The extent, thickness, and mined area of the NW cor. SWUNEUSWU sec.16------256 26 Lower Hartshorne coal bed are shown on plate 3. The NW cor. SW,MSWU sec.16------­ 280 30 NW cor. SWUSWUSW% sec.19------­ 307 8 outcrops of all other coal beds are shown on plate 3, Center NWUSWUSWU sec.19------­ 275 32 Center NWUNE% sec. 23------231 5 and the thickness measurements for these coal beds are Do.2 ______------______---- ___ ------252 3 listed in table 2. See footnotes at end of table. GEOLOGY OF THE GREENWOOD QUADRANGLE, ARKANSAS-OKLAHOMA All

TABLE 2.-Selected coal thickness measurements. in the Greenwood Lower Hartshorne coal bed, near the base; the Upper quadrangle-Continued Hartshorne coal bed, 60-90 feet above the Lower Hart­ Depth Thickness shorne coal bed; the McAlester coal bed, near the middle Approximate location of coal of coal (feet) (inches) of the formation; and the Stigler coal bed, near the top of the formation. Oklahoma The Lower Hartshorne coal bed is the thickest, most T. 7 N., R. S7 E. BW cor. sec. 5 '------Outcrop 16 widespread, and most important economically in the Center SE34NE34NW34 sec. 29 '------Outcrop 16 BW cor. SW34SEUNE34SW34 sec. 29. '------Outcrop 16 Greenwood quadrangle. It lies near the base of the McAlester Formation, and in some areas the "bed" is t Unnamed coal bed in Atoka Formation. I Unnamed coal bed in McAlester Formation. actually a zone of 1-7 beds. The thickness of the coal, a McAlester (?) coal bed in McAlester Formation. ' Stigler coal bed in McAlester Formation. the a1nount of overburden, the mined areas, and the out­ ' Charleston (?) coal bed in Savanna Formation. crop of the Hartshorne coal bed are shown on plate 3. All coal in the Greenwood quadrangle is classified The estimated reserves of coal in the Lower Hartshorne as low-volatile bituminous (Haley, 1960, pl. 62; Trum­ coal bed in the Arkansas part of the quadrangle after bull, 1957, pl. 17) on the basis of the percentage of dry mining are listed in table 3, and the estimated original mineral-matter-free fixed in the coal, in ac­ reserves, the estimated amount of coal mined and lost cordance with the specifications of the American Society in mining, and the estimated recoverable reserves of coal for Testing and Materials ( 1939) . in the Lower Hartshorne coal bed in the same area are The estimated reserves of coal listed in tables 3 and listed in table 4. 5 are tabulated in categories of amount of overburden, TABLE 3.-Estimated remaining reserves of coal in the Lower thickness of coal, and abundance of reliable thickness Harts horne coal bed in the Arkansas part of the Greenwood data in accordance with the standards and procedures quadrangle [In millions of short tons] adopted by the U.S. Geological Survey (Averitt, 1961, p. 14--26). The original, remaining, and recovera;ble Thickness of coal (inches) Overburden (feet) reserves of coal listed in table 4 are also categories H-28 28-42 >42 Total conformable to those of Averitt. Measured and indicated reserves Trumbull (1967, p. 341-345, and pl. 1'7) described the 0-1,000 ______------3. 638 50.275 48. 645 102. 558 rank, thickness, thickness of overburden, amount of re­ 1, ooo-2, ooo ___ ------__ ------2. 487 6. 338 8. 825 liable thickness data, and mined areas of the Lower 2, OOG-3, OQO ___ ------___ ------______------Hartshorne coal bed in the Oklahoma part of the Total------3. 638 52.762 54.983 111.383 Greenwood quadrangle, but the amount of coal esti­ Inferred reserves mated to be in this area cannot 'be determined from his 0-1,000------4. 763 45.560 11.368 61.691 report. The coal-bearing part of this area is about one­ 1,000-2,000 ______------. 243 24. 092 13. 561 37.896 half as large as the coaVbearing part of the quadrangle 2,000-3,000------_--_--_--_--_-_-_6_.0_17 __ 1_. 7_51 __ 7._768_ in Arkansas, and the coal has about the same average TotaL------5. 006 75.669 26.680 107.355 thickness; therefore, it seems reasonable to believe that Total reserves this area contained as much as 140 million short tons of 0-1,000 ______------8. 401 95.835 60.013 164.249 coal prior to mining. 1,000-2,000 ______------. 243 26.579 19.899 46.721 2,()()()-3,000 ___ ------6.017 1. 751 7. 768 Coal beds in the Atoka Formation Total------8.644 128.431 81.663 218.738 An Atoka ooal bed crops out in the Greenwood quad­ TABLE 4.-Estimated original, remaining, and recoverable reserves rangle along the county road in NE¥..,SE% sec. 36, T. of coal in the Arkansas part of the Greenwood quadrangle 6 N., R. 31 W. This coal bed, near the top of zone W, is [In millions of short tons] known to extend eastward from the quadrangle for more than 45 miles. A coal bed was penetrated by the Amount of Coal bed Original coal mined Remaining Recoverable reserves and lost in reserves reserves Gann well (well 12) at a depth of 438 feet. This coal mining bed was not found at the surface in the Greenwood Lower Hartshorne ______315. 552 96. 814 218.738 109.369 quadrangle; however, it was found in the quadrangle Upper Hartshorne ______28.004 14.002 to the east (Ha,ley, 1966, pl. 1) . 28.004 ------TotaL ______----- 343.556 96.814 246.742 123.371 Coal beds in the McAlester Formation Four McAlester coal beds are known in the Green­ The Upper Hartshorne coal bed, 60-90 feet above the wood quadrangle. They are, in ascending order, the Lower Hartshorne coal bed, is present only in the south.. A12 GEOLOGY OF THE ARKANSAS VALLEY COAL FIELD ern part of the quadrangle. The outcrop of the coal bed be equivalent to the Charleston coal bed which is at is shown on plates 1 and 3, and coal-bed thicknesses are this stratigraphic position elsewhere in Arkansas. listed in table 2. The estimated original reserves of OIL AND GAS Upper Hartshorne coal in the Arkansas part of the quadrangle listed in table 5 are modifications of those Oil has not been discovered in the Greenwood quad­ reported by Haley ( 1960, table 1, p. 806). The estimated rangle; however, streaks and blebs of solid carbona­ amount of coal mined and lost in mining, the remaining ceous material (dead oil) are present in the upper part reserves, and the recoverable reserves in the Upper of the St. Clair Limestone in well 9. The first produc­ Hartshorne coal bed in the same area are listed in ing gas well in Arkansas was drilled 1% miles east of table 4. the quadrangle on the Hartford anticline in 1902. This The McAlester coal bed, near the middle of the well, the Oil and Gas Co. Duncan 2, is the dis­ McAlester Formation, is present only in the southwest­ covery well for the Mansfield gas field. The discovery ern part of the quadrangle. The outcrop of the coal bed wells for three other gas fields in the Greenwood quad­ is shown on plates 1 and 3, and the measured thicknesses rangle are the Shell Oil Co. Western Coal and Mining are recorded in table 2. The reserves of coal in the Co. (well 2) in the Bonanza field (pl. 3) , the Le Flore McAlester coal bed were not estimated because the coal County Gas and Electric Co. Hill 1 drilled west of the is thought to be less than 14 inches thick throughout its report area in the Poteau-Gilmore field, and an unknown extent in the quadrangle. well in the Rock Island field. These wells and others The Stigler coal bed, near the top of the McAlester drilled in or near the Greenwood quadrangle are de­ Formation, is known only in the southwestern part of scribed in table 6. the quadrangle. The outcrop of the coal bed is shown on Gas in the Greenwood quadrangle has been produced plates 1 and 3, and the measured thicknesses are tabu­ from the St. Clair Limestone, the Penters Chert, the lated in table 2. Reserves of coal in the Stigler coal bed Morrow Series, the Atoka Formation, the Hartshorne were not estimated. Sandstone, and the lower part of the McAlester For­ mation. Gas in the Mansfield gas field has been produced TABLE 5.-Estimated original reserves of coal in the Upper Hart­ from standstone units mostly in zone W (Haley, 1966, shorne coal bed in the Arkansas part of the Greenwood quad­ rangle p. 20). Gas in the Bonanza gas field has been produced [In millions of short tons. Modified from Haley (1960, table 1, p. 806)] from the St. Clair Limestone, Penters Chert, lower part of the Morrow Series, and middle part of the Atoka Thickness of coal (inches) Overburden (feet) Formation. The gas from the Poteau-Gilmore gas field 14-28 28-42 >42 Total comes from the Hartshorne Sandstone and from the Measured and indicated reserves lowermost sandstone in the McAlester Formation. Gas in the Rock Island gas field is from the upper one-third 0-1,000______11.417 0.188 ------11.605 1, 000-2, 000.------of the Atoka Formation. 2, 000-3, 000.------Gas is found in many of the Morrow, Atoka, Hart­ TotaL------·------· 11.417 .188 ------11.605 shorne, and lower McAlester sandstone beds. The extent Inferred reserves and volume of gas in these rocks is dependent upon structure and lithologic changes. The importance of 0-1, 000.------··--·------15. 983 ------15. 983 1, 000-2, 000.------. 416 ------. 416 lithologic entrapment is exemplified by wells 10, 11, 12, 2, 000-3, 000 .. ------14 (table 6), all of which produce or have shows of gas TotaL______16.399 ------16.399 from rock units that crop out updip from the wells. Total reserves BUILDING STONE 0-1,000.------27. 400 0. 188 ------27. 588 1, 000-2, 000.------. 416 ------. 416 2, 000-3,000.------Slabs and blocks of weathered sandstone frmn the TotaL------27.816 .188 ------28. 004 Atoka Formation have been used on the exterior of many of the buildings in the area. Building stone has

Coal beds in the Savanna F.ormation been quarried from the Hartshorne Sandstone in sees. 9 and 10, T. 8 N., R. 27 E.; sec. 20, T. 6 N., R. 32 W.; and One coal bed is known in the Savanna Formation in sec. 35, T. 7 N., R. 31 W.; and from a sandstone in the the Greenwood quadrangle, but it seems likely that McAlester Formation in sec. 4, T. 7 N., R. 27 E. Most others exist. The one known coal bed is 4 inches thick of the Hartshorne Sandstone used in building is taken and is exposed near the base of the Savanna Formation from long foreset beds of remarkably uniform thick­ in sec. 6, T. 4 N., R. 32 W. (pl. 1). This coal bed could ness. It is a popular building stone because of its uni- TABLE 6.-Description of selected wells drilled in or near the Greenwood quadrangle as of January 1, 1961,.

Well Total Reported Depth of Reported Comple· No. Company name Lease name Location (EL, east line; NL, depth eleva- Electri- Stratigraphic zone of production production tion Remarks (pls. north line; SL, south line; WL, (ft) tion callog production (ft) (cu ft per date 1-4) west line) (ft) day)

0 Shell Oil CO------Western Coal 339 ft north and 363 ft west of 8, 030 484 Yes •••.. Prairie Grove Member...... 7, 075-7,085 3, 820, 000 1003 l":l and Mining center sec. 31, T. 7 N., R. 31 W. St. Clair Limestone .•••••••• 7,88Q-7,890 1,880,000 0 Co.3. 2 _____ dO------Western Coal 620ft south and 450 ft west of 10, 924 505 •.• do _____ Middle part, Atoka Forma- 2, 985 50, 000 Apr. 1962 Discovery well of Bonanza s and Mining center sec. 36, T. 7 N., R. 32 W. tion. Field. First commercial 0 Co.l. St. Clair Limestone ______7, 936-7, 958 9, 400, 000 production in Arkansas from t-<1 Powell Dolomite------8, 802-8,812 100, 000 rocks older than Devonian. ---.•dO------.•...•. 8, 924-8, 930 70, 000 Rock samples examined and 0 Roubidoux Formation ______9, 857-9, 975 Show of gas_ logged by B. R. Haley to "':j 7,400 ft and by S. E. Frezon from 7,400 to 10,924 ft. De­ scribed by Haley and Frezon ~ (1965). l":l 3 _____ do ______E. Hamilton A-L- 895ft south and 330ft west of ------Being drilled. center sec. 12t T. 6 N., R. 31 W. 0 4 _____ dO------Western Coal 400ft north ana 500ft east of 8,057 1518 Yes _____ Middle part, Atoka 4,618-4,638 700,000 Nov.1962 pj and Mining center sec. 35, T. 7 N,. R. 32 W. Formation. l":l Co.2. Prairie Grove Member ______7,-113-7,120 275,000 l::iij Penters Chert and St. 7-740, 7, 874 21, 000, 000 Clair Limestone. St. Clair Limestone ______7,946-7,958 2,500,000 ~ 5 _____ dO------Young 1-2------1,980ft from SL and 1,980 ft from 8,150 582 ••• do ______dO------7, 901-8,045 5, 600,000 June 1962 8 WL NW~ sec.2, T. 6 N., R. t:::1 32 W. 6 _____ dO------AceeMilkCo.1-3 1,320ftsouthand1,980ftwestof 8,182 548 ••• do.---- Prairie Grove Member.••••• 7,23Q-7,290 3,800,000 Nov.1963 D NE cor. sec.~~ T. 6 N., R. 32 W. Penters Chert------7,89Q-7,940 2,900,000 7 Le Flore County Tompas-Back- Center SWUS wU sec. 31, T. 9 4, 845 2 670 ------Atoka Formation ••• ------Gas a______1944 Gas and Electric bone 1. N ., R. 27 E. ~ Co. '='pj 8 ....•dO------McClure!______Center NEUS W~NWU sec. 7, 2, 771 2 485 No .•. ______------Dry------1923 T. 8 N., R. 27 E. ~ 9 Midwest Oil Corp ___ F. Morris L ______3,300 ft from SL and 2,840 ft 9,216 1476 Yes _____ Zone P, Atoka Formation..• 5,205-5,262 2,000,000 1961 Discovery well of deeper gas in 0 from WL sec.12, T. 7 N., R. Rock Island gas field. Well t'4 26 E. is 3,860 ft west of Greenwood quadrangle. Rock samples ....1::9 examined and logged by S. E. Frezon. >pj 10 LeFlore County Littman 26------Center NEUNWUNW~ sec. 2,615 2 470 No .•.•.• Upper part, Atoka For­ ------Gas a______1922 400ft west of Greenwood Gas and Electric 18, T. 8 N., R. 27 E. mation. quadrangle. Co. 11 _____ do ______Littman 25 •. ______CenterS WUNWUNW~ sec. 1,607 2 470 ••• do •••••.••••dO.------Gas a______1922 700ft west of Greenwood ~ 18, T. 8 N;., R. 27 E. quadrangle. rJl 12 J. W. Nichols Gann L------Center NE~S W~ sec.15, T. 6,005 565 Yes •••• ----.•do •••••..• ------Dry------Sept. 1957 Gas escaping around casing in rJl> Exploration Co. 5 N., R. 31 W. March 1958 (Haley, 1966, I table 3). Rock samples ex­ 0 amined and logged by B. R. Haley. Described by Haley (1966). 13 Wheeler and Ryan ___ Sebastian County 2,210 ft from SL and 2,146 ft 6, 016 563 •.•do ••..• ------_------.. ----- Dry------April1962 Rock samples examined and Coal and from WL of sec.l4, T. 5 N., logged by R. B. Haley. 0~ Mining Co.l. R. 32 W. 14 Atheletic Mining -----dO------Center NEUNEUS W~ sec. 4,335 2 560 No .••..• Zone W, Atoka Formation.. 3,380 Show of gas ------and Smelting Co. 14, T. 5 N., R. 32 W. ~ 15 Le Flore County F. L. Holton 29. __ Center S W~NE~S W~ sec. 1, 505 2 630 ..• dO.------Gas •------1923 Gas and Electric Co. 34, T. 8 N. R. 27 E. 16 _____ do ______Mooneyahm 22.••• Center SE~NWUNW~ sec. 2,487 2 690 ..•dO------Gas •------1921 32,T.8N.,R.27E. 17 ....•dO------Kilgore-Cedars 5.• Center NW~SEUNE~ sec. 3,250 1600 ••• dO------·-··-···· Gas a______1929 9, T. 7 N., R.27 E. See footnotes at end of table.

>1-' ~ >...... ~

TABLE 6.-Description of selected wells drilled in or near the Greenwood quadrangle as of January 1, 1964-Continued G:) t;rj Well Total Reported Depth of Reported Comple­ 0 No. Company name Lease name Location (EL, east line; NL, depth eleva- Electrl- Stratigraphic zone of production production tion Remarks t"" (pis. north line; SL, south line; WL, (ft) tion callog production (ft) (cu ft per date 0 1-4) west line) (ft) day) ~ 18 Mobil Oil Co ....•..• W.K. VeazeyL •• 3,630ftfromSLand840ftfrom 13,871 11,152 Yes _____ Zone W, Atoka Formation .• 5,494-5,510 25,000 1962 Rock samples examined and 0 WL sec. 28, T. 7 N., R. 27 E. logged by B. R. Haley to l%j 13,400 ft and by S. E. Frezon from 13,400 to 13,871 ft. 19 LeFlore County Garrett 55------Center SE~NE~N W~ sec. 30, 1,478 t 650 No------Gas a______1925 Gas and Electric T. 7 N., R. 27 E. ~ Co. 20 _____ dO------Garrett 76------Center SE~N W~N W~ sec. 30, 1, 539 2 635 ..• dO------Gas a______1927 300ft west of Greenwood > T. 7 N~R. 27 E. quadrangle. P:l 21 _____ dO------Slocum 78------Center S.!!i~S W~N W~ sec. 30, 1, 596 2 620 .•• dO------___ ------______------Gas a ______1927 Do. T.7N~R.27E. 22 _____ do ______Hall 56. ______Center S.!!i~S W~NE~ sec. 30, 2,134 2 655 •.• dO------Gas a______1925 T. 7 N., R. 27 E. U1~ ~ 23 Central Coal and Hartford L------4,200 ft from NL and 1~00 ft from 4, 270 2 670 ••• dO------2, 210 Show of gas. 1914 2,900 ft south of Greenwood rp Coke Co. EL sec. 21, T. 4 N., .~:t. 32 W. 3, 587 •.•..do ______quadrangle. 4, 035 ____ .do ______