Copyright © 1979 Ohio Acad. Sci. 0030-09r>0/79/0()0r)-0227/$1.50/0

BARITE CONCRETIONS FROM THE CLEVELAND SHALEIN NORTH-CENTRAL OHIO1

WILLIAM F. HOLDEN2 and ERNEST H. CARLSON, Department of Geology, Kent State Uni-versity, Kent OH 44242

Abstract. Concretions composed predominantly of barite occur in the ClevelandShale of north-centra] Ohio. They have been traced about 8 km through discon-tinuous exposures along the Vermilion River in Erie and Lorain Counties. Theseseptarian concretions are flattened in the plane of bedding and average 0 cm in length.The concretions contain a black matrix largely composed of fine crystalline barite,surrounded by a fine-grained pyrite rich shell. Septa composed predominantly ofmore coarsely crystalline barite are generally restricted to the matrix. Although thesource of the barium is unknown, the stratigraphic restriction of the occurrence, thesedimentary character of the barite, and the upper Devonian age of the ClevelandShale suggest that the occurrence may be related to events that formed importantbedded barite deposits of mid-Paleozoic age in Arkansas, Nevada and California.

OHIO J. SCI. 79(5): 227, 1979

An occurrence of septarian concretionsalong a northern portion of the VermilionRiver in Ohio has been known for sometime. These concretions were describedby Herdendorf (1963) as being commonin the shale bluffs and gravel bars of themajor streams in the Vermilion (15minute) Quadrangle, but the fact thatthey are composed primarily of baritehas only recently been recognized. Thepurpose of this paper is to describe theseconcretions and their occurrence in detail.

METHODSMineralogical determinations were made by

x-ray diffraction methods using a Debye-Scherrer camera. Thin sections were examinedfor study of internal structures and for as-sistance in the identification of the minerals.Samples of shale were analyzed for barium, andconcretions were analyzed for strontium byatomic absorption spectrometry. Shales werefused with lithium metaborate and dissolved ina 5% nitric acid solution prior to analysis, andbarite concretions were prepared for analysis bydissolving them in a solution of disodiumEDTA.

RESULTSBasic Geology. Exposed along the

northern portion of the Vermilion River

xManuscript received 29 August 1978 and inrevised form 11 January 1979 (#78-51).

2Present address: P.O. Box 18878, Denver,Colorado 80218.

are the Cleveland and Bedford Shales.The Cleveland, the topmost member ofthe Ohio Shale, is composed chiefly ofblack, compact and fissile shales con-taining some layers of thin, argillaceouslimestone. It is of Upper Devonian age.The Bedford Shale overlying it is LowerMississippian (Willis 1912). In the Ver-milion River area, it is a red shale, al-though at its base it is gray and inter-gradational with the black shales belowit.

The barite concretions can be tracedthrough discontinuous exposures for adistance of about 8 km in eastern Erie andwestern Lorain Counties. Seven loca-tions where the concretions were foundare shown in table 1. At sites 1 through4 the concretions were found loose alongthe bank of the river. They were graywith weakly pronounced septa, with theexception of location 3, where they werebrownish and the septa were stronglypronounced. A search of the wall rockat these locations did not reveal any inplace occurrences, but these may havebeen obscured by debris from the cliffsabove.

At sites 5 through 7 concretions werefound in place, restricted to a narrowstratigraphic zone approximately 2 mthick and lying within the Cleveland

227

228 W. F. HOLDEN AND E. H. CARLSON Vol. 79

TABLE 1

Localities for the concretions.

Location 1 Mill Hollow Bacon Woods Park,beginning along the north bankapproximately 300 m west of theNorth Ridge Road bridge.

Location 2 Mill Hollow Bacon Woods Park,beginning along the south bankabout 500 m east of the samebridge.

Location 3 Approximately 200 m north of theGarfield Road bridge, along thesouth and east banks.

Location 4 Approximately 1000 m south of theRoute 113 bridge, along the westbank and a stream bar.

Location 5 Approximately 30 m north of Route60 bridge, just south of the junctionwith Route 113; in place occurrencealong the western bank. This siteis most accessible from the north.

Location 6 Approximately 200 m south of thejunction of the East Fork of theVermilion with the Vermilion,along the East Fork. Concretionsin place along southern walls.

Location 7 Directly west of the VermilionRoad bridge over a tributary, justsouth of the Gifford Road cutoff;concretions in place along southernbank. Not easily accessible.

Shale near its contact with the overlyingBedford Shale. This contact is generallyobscure in the Vermilion area. The con-cretions were typically disc-shaped, flat-tened in the plane of bedding. Althoughthe distribution of the concretions washighly variable, the spacing of centers ofadjacent concretions would average one-half meter in a cliff exposure.

The concretions' length varied from 1.7to 8.6 cm (see table 2). Weight varied

TABLE 2

Barite concretion physical data.

Min.Max.Av.

Length(cm)

1.78.64.3

Weight(a\\S)

4.28240.0159.55

Bulk SpecificGravity

Loose

2.644.553.91

In Place

3.804.904.12

from 4.28 to 240.01 g with an average of59.55 g. When sectioned, the concre-tions displayed four general regions: anouter rind of gray-gold matrix; an

inner, extensively fractured, gray to blackmatrix; a hard, outer septal material; anda softer, inner septal material. Theseseptal fillings appear as white veinletsthat markedly contrasted with the darkermatrix. They thin rapidly toward theexterior, and pinch out within the outershell. The veinlets average 2 mm inthickness and reach a maximum widthof up to 6 mm near the concretion centers(see figs. 1 and 2).

The outer matrix is present only onconcretions found in place, although looseconcretions may contain traces of it.This outer rind averages 4 to 5 mm inthickness, and contains about an equalproportion of finely crystalline pyrite andbarite. The inner matrix is composedlargely of barite crystals less than 0.1 mmin size. Minor, small anhedral grains ofpyrite occasionally are found. In addi-tion, x-ray diffraction indicate traceamounts of quartz. The black color ofthe matrix is due to the presence of or-ganic matter. When pulverized matrixwas heated in a test tube over a bunsenflame (Twenhofel and Tyler 1941), dense,white fumes evolved and droplets of oilcondensed on the walls of the tube. Nodefinite visible traces of fossils could beobserved, however, in any of the bariteconcretions.

Fracture systems found in the con-cretions are highly variable. Generally,fracture walls are lined with chalcedony,which displays colloform, oolitic andfibrous-radiating habits. The chalcedonyis characterized by a muddy brown colorunder the petrographic microscope. Theinner-septal material consists predomi-nantly of white to gray, anhedral baritegrains, 1-2 mm in diameter. Colorless,anhedral grains of yellowish-white, fluo-rescent calcite are present also. Al-though the septa are generally completelyfilled, euhedral crystals of barite andquartz occasionally line the walls of smallvugs.

External differences between the inplace and the loose concretions appear tobe related to the retention or loss of thepyrite-rich rind. All concretions foundin place display this rind in some form oranother. Hypothetically, as the con-cretions are weathered from the shalebluffs, the rim is removed due to the

Ohio J. Sci. BARITE CONCRETIONS IN NORTHERN OHIO 229

FIGURE 1. (Top) Interior of an in place concretion. The pyrite and barite rim enclosea matrix of fine-grained barite. Recrystallized barite is in the center and the fracturesare lined with chalcedony. Note that the fractures terminate abruptly at the pyrite-barite rim.

FIGURE 2. (Bottom) The interior of a loose concretion showing the penetration of thefractures to the exterior.

relatively rapid oxidation of pyrite. Theintricate septa fillings, because they con-tain minerals resistant to weathering,then stand out in relief. A completegradation exists between the two ex-tremes of no septa and prominent septadevelopment (see fig. 3).

To test this "weathering" hypothesisin the laboratory, several concretionswere placed in a bath of aqua regia, whichwas used because it oxidizes pyrite

rapidly but does not affect barite (Dolezalet al 1968). Twelve hours' exposure tothe acid was generally sufficient to re-move the pyrite rind and expose the septafillings. There were no apparent dif-ferences between naturally and artificiallyweathered specimens. A small differencein average bulk specific gravity betweenin place concretions (4.12) and loose con-cretions (3.91) would also be explained bythis hypothesis.

230 W. F. HOLDEN AND E. H. CARLSON Vol. 79

FIGURE 3. Representative examples of the three types of concretions: from left toright, in place with no septa visible, loose with most septa visible, loose with all septavisible.

A possible areal variation in the in-ternal structure was noted: of the threelocations where concretions were found inplace, those found at site 5 had the bestdeveloped septal fractures. Often theentire central portion of the concretionconsisted of coarse, anhedral crystals.Those from location 6 and 7, on the otherhand, had only minor fractures and nosignificant development of more coarselycrystalline interiors. Since only a smallnumber of concretions were collected atthese three locations due to the difficultyof removing them from the shale wall,this may be only an apparent variation.

In order to determine if the shale con-taining concretions was barium-rich, shalesamples were collected from location 5 at5 one meter intervals; two above, twobelow, and one at the approximate cen-ter of the concretionary zone. Pro-gressing downward, respective values de-termined were 221, 298, 634, 1437 and 659ppm of barium, an average of 650 ppm.Worldwide mean barium content for allshales is reported by Wedepohl (1972) as

546 ppm. The Cleveland Shale thusdoes appear to have a slightly higher thanaverage barium content near the con-cretionary zone, with definite strati-graphic control. As an additional test,two concretions were analyzed for stron-tium content, with a concretion from site2 yielding 5962 ppm Sr and one fromsite 3 yielding 6055 ppm Sr. Thesestrontium values fall within the reportedrange for bedded barite (up to 7000 ppm)as reported by Brobst (1973).

DISCUSSIONConcretionary forms of barite have

been found a number of times, occasion-ally in the form of septaria (Samoilov1917, Carpenter and Fagan 1969, Chu-chrov and Yermilova 1970) more often asaggregates of oolites, or concretions dis-playing radial structure. Little agree-ment exists as to the genesis of these ad-mittedly unusual occurrences. As bariteis relatively insoluble in sea water, itstransportation to and concentration atthe depositional sites do indicate highly

Ohio J. Sci. BARITE CONCRETIONS IN NORTHERN OHIO 2;M

unusual conditions. Genesis is believedto occur where barium-rich hydrothermalfluids were introduced to the sedimentsduring deposition (Revell e and Emery1951, Carpenter & Fagan 1969) or wherebarium was transported via surfacewaters from a nearby land source (Haageand Krumbiegc! 1968), or via a specu-lative biogeochemical process in whichthe concentrations were produced byamassing remains of a group of rhizopodsknown to concentrate barium withintheir body structures (Samoilov 1917,Wetzcl 1970).

When considering the origin of theseconcretions, it is interesting to notetheories concerning the origin of beddedbarite deposits. The major depositsmined in the United States today are inArkansas, Nevada and California, andconsist of bedded, fetid, dark-gray toblack, fine-grained barite. These de-posits appear to be restricted to rocks ofmid-Paleozoic age (Brobst 1973). Earlyworkers with the Arkansas deposits be-lieved they were replacement in origin(Scull 1958), although later workersleaned toward a sedimentary origin(Zimmerman and Amstutz 1964, Shawe,Poole and Brobst 1969, Zimmerman1970). In a study comparing the Meg-gen deposits of West Germany with thoseof Arkansas, Zimmerman (1970) pro-vided exhaustive evidence of the sedi-mentary features of both deposits andnoted further that the sedimentary fabricfound is indicative of formation undertidal flat or evaporite conditions; hefurther postulated the source for bariumas sub-marine volcanic activity or anerosion of nearby land masses containingbarite deposits. Workers with the Ne-vada deposits also leaned toward a sedi-mentary origin (Shawe, Poole and Brobst1969, Rye, Shawe and Poole 1978).

The barite concretions found along theVermilion River are suggestive of someaspects of bedded barite deposits. TheCleveland Shale is marine in origin, UpperDevonian in age. The shale was de-posited in a reducing environment as in-dicated by the presence of abundantcarbonaceous material and pyrite. Septaformation generally is considered to bea shrinkage phenomenon (Richardson

1919). The stratigraphic restriction andscptarian character of the barite nodulesthemselves indicate they have a sedi-mentary origin as well, probably havingformed during the diagenesis of the en-closing sediments. The precipitation ofthe barite of the matrix occurred underreducing conditions as indicated by itsclose association with both carbonaceousmaterial and pyrite. The formation ofthe pyritc rich shell marked, the close ofthe concretionary growth stage. Thesepta formed later and subsequently werefilled, presumably during lithification ofthe sediments. But these two later de-velopments have no bearing on the origi-nal formation of the barite itself.

Brobst (1973) speculated aboutwhether or not the apparent restrictionof bedded deposits to rocks of mid-Paleozoic age was coincidental. Whilethe occurrence of barite concretions inthe Vermilion River area does not con-stitute a deposit as such, their existenceand the higher than average barium val-ues for the enclosing shales prove thatsome type of concentrating process wasoperating in Ohio during Upper Devoniantime. The lateral extent of the depositcould be somewhat greater than reportedhere since exposures in the area are gen-erally quite poor. The mid-Paleozoicsedimentary barite association thus ap-pears to extend into the north-centralpart of the United States. The explora-tion for economic deposits of beddedbarite of this age in the Appalachia regionalso would seem justified.

The source of the barium for the Ver-milion River deposits has not been de-termined. The nearest center of barite-bearing epigenetic mineralization occursin northwestern Ohio along the flanks ofthe Findlay Arch. At present, however,there is no evidence linking those depositswith the Vermilion River barite.

Acknowledgments. The writers wish to ex-press their gratitude in particular to Mr. LaRueBiddinger, Mr. Clarence Raver and Mr.Thomas Trebonik for bringing to our atten-tion three of the barite localities. The atomicabsorption analyses were performed by GeorgeMychkovsky, and the photographs of the con-cretions were taken by Dale Beikirch. KentState, Department of Geology ContributionNo. 172.

232 W. P. HOLDEN AND E. H. CARLSON Vol. 79

LITERATURE CITEDBrobst, D.A. 1973 Barite. In: D. A. Brobst

and W. P. Pratt (eds.), United States MineralResources, U.S.G.S. Prof. Paper 820: 75-84.

Carpenter, R. H. and J. M. Fagan 1969 Baritenodules in the Athens Shale in NortheasternTennessee and southwestern Virginia. South-east. Geol. 10: 17-29.

Chuchrov, F. V. and L. P, Yermilova 1970Zur Schwefel-isotopenzusammensetzung inKonkretionen. Dtsch. Ges. Geol. Wiss.,Ber., Reihe B. Mineral. Lagerstattenforsch15: 225-267.

Dolezal, J., P. Povondra and Z. Sulcek 1968Decomposition techniques in inorganic an-alysis, Transl. by Ota Sofr. AmericanElsevier Publishing Co.

Haage, R. and G. Krumbiegel 1968 UeberDie Barytvorkommen in Tertiaer des Geisel-tales. Geologie 17: 1195-1207.

Herdendorf, C. E. 1963 The Geology of theVermilion Quadrangle, Ohio. M.S. Thesis,Ohio University, Athens, OH.

Revelle, R. R. and K. O. Emery 1951 Bariteconcretions from the ocean floor. Geol. Soc.Amer. Bull. 62: 707-723.

Rye, R. O., D. R. Shawe and F. G. Poole 1978Stable isotope studies of bedded barite atEast Northumberland Canyon in ToquimaRange, central Nevada. Jour. ResearchU.S. Geol. Survey 6: 221-229.

Richardson, W. A. 1919 On the origin ofseptarian structure. Mineral. Mag. 18: 327-338.

Samoilov, J. V. 1917 Paleophysiology: theorganic origin of some minerals occurring insedimentary rocks. Mineral. Mag. 18: 87-98.

Scull, B. J. 1958 Origin and occurrence ofbarite in Arkansas. AR. Geol. and Cons.Com., Info. Circ. 18.

Shawe, D. R., F. G. Poole and D. A. Brobst1969 Newly discovered bedded barite de-posits in East Northumberland Canyon,Nye County, Nevada. Econ. Geol. 64:245-254.

Twenhofel, W. H. and S. A. Tyler 1941Methods of study of sediments. McGrawHill, New York. 183 pp.

Wedepohl, K. H. (ed.) 1972 Barium. Hand-book of geochemistry. Springer Verlag, Ber-lin. Vol.2.

Wetzel, W. 1970 Die Erscheinungformen desBaryt in jungkretazischen und alttertiaerenSedimenten. Neues. Jahrb. Mineral. 1:25-29.

Willis, B. 1912 Index to the stratigraphy ofNorth America, U.S.G.S. Prof. Paper 71:315.

Zimmerman, R. A. 1969 Stratabound baritedeposits in Nevada; rhythmic layering, dia-genetic features, and a comparison withsimilar deposits of Arkansas. Mineral. De-posita 4: 401-409.

and G. C. Amstutz 1964 Small scalesedimentary features in the Arkansas baritedistrict. In: G. C. Amstutz (ed.) Develop-ments in Sedimentology, Vol. 2 (Sedimentol-ogy and Ore Genesis), Elsevier PublishingCo., New York.