Callipterid peltasperms of the Dunkard Group, Central Appalachian Basin

23 Pages·2013·5.24 MB·English

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InternationalJournalofCoalGeology119(2013)56–78
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International Journal of Coal Geology
journal homepage: www.elsevier.com/locate/ijcoalgeo
Callipterid peltasperms of the Dunkard Group, Central
Appalachian Basin
WilliamA.DiMichelea,⁎,HansKerpb,RobertaSirmonsa,NickFedorkoc,ViktorasSkemad,
BascombeM.BlakeJr.e,C.BlaineCecilf
aDepartmentofPaleobiology,NMNHSmithsonianInstitution,Washington,DC20560,USA
bForschungsstellefürPaläobotanik,UniversityofMünster,Germany
cCoveGeologicalServices,Moatsville,WV26405,USA
dPennsylvaniaGeologicalSurvey,Middletown,PA17057,USA
eWestVirginiaGeologicalandEconomicSurvey,Morgantown,WV26508,USA
fU.S.GeologicalSurvey,NationalCenter,Reston,VA20192,USA
a r t i c l e i n f o a b s t r a c t
Articlehistory: TheDunkardGroupistheyoungestlatePaleozoicrockunitintheCentralAppalachianBasin.Itsage,however,
Received8April2013 remainscontroversial.Initssouthernandwesterntwo-thirdstheDunkardiscomprisedlargelyofredbeds,sand-
Receivedinrevisedform3July2013 stoneandsiltstonechanneldepositsandpaleosols.Initsthickest,mostnortherlyexposures,insouthwestern
Accepted4July2013
Pennsylvania,northernWestVirginia,andeast-centralOhio,muchofthelowerpartoftheunitiscomposedof
Availableonline8August2013
coals, non-marine limestones and gray, often calcareous, paleosols. Age dating is confounded by the non-
marinenatureofthedepositandbythelackofdateablevolcanicashbeds.Dunkardfossilsincludeplants,verte-
Keywords:
brates,andbothaquaticandterrestrialinvertebrates.Mostofthefossilgroupspointtoanageverycloseto,ifnot
Dunkard
Callipterids including, the Pennsylvanian–Permian boundary, though the exact position of that boundary is uncertain.
Permian CallipteridsmaketheirfirstappearanceintheDunkardflorainthemiddleoftheWashingtonFormationandcon-
Pennsylvanian tinueintotheGreeneFormation,butindifferentbedsfromthosecontainingwetlandfloralelements.Publication
Paleoecology oftheseplantsinthe“PermianFlora”ofFontaineandWhite(1880)createdanimmediatecontroversyaboutthe
Paleoclimate ageoftheunitbecauseCallipterisconferta(nowAutuniaconferta)was,atthetime,consideredtobeanindexfossil
forthebaseofthe Permian.Subsequentcollecting hasrevealedthesecallipterdstocomprisefourspecies:
A.conferta,Autunianaumannii,LodeviaoxydataandRhachiphyllumschenkii.Callipterids–andtheconiferswith
which they are sometimesassociated – are typically found inseasonallydry equatorialenvironments and
mostlikelyconstituteanenvironmentallycontrolledbiofacies.Thisbiofaciesisnotwellknown,resultinginlim-
itedbiostratigraphicutility.
PublishedbyElsevierB.V.
1.Introduction lineage,theyoriginatedduring,orpriorto,theMiddlePennsylvanian
(Pšeničkaetal.,2011),andlaterradiatedextensively(DiMicheleetal.,
ThecallipteridsareagroupoflatePaleozoictropicalplants,charac- 2005;Kerp,1988;Naugolnykh,1999).Thisradiationappearstohave
terizedbyfoliageformerlyclassifiedasCallipteris.Thisgenuswassplit occurredinenvironmentswithseasonallydistributedmoisture(Kerp,
into five genera when the generic name appeared to be illegitimate 2000), probably under wet-subhumid to dry-subhumid climates
(KerpandHaubold,1988).Reproductiveorgansrevealedthatoneof (terminologysensuCecilandDulong,2003).Whereaspeltaspermsin
the resulting genera, Autunia, is a peltasperm (Kerp, 1988). Other generalspreadwidelythroughoutPangeantropicalandnortherntem-
callipteridsalsoappeartobepeltasperms(e.g.,NaugolnykhandKerp, perate latitudes (see discussion in Naugolnykh and Kerp, 1996), the
1996;PoortandKerp,1990)anditcanbeassumedthatthisistruefor callipterids formed prominent elements mainly in Permian tropical
most if not all callipterids. Peltasperms are related to, and possibly floras.ThenearabsenceoftheseplantsfromtypicalLatePennsylvanian
descended from, the callistophytalean pteridosperms (Crane, 1985; wetlandflorasandtheiroccurrencesindepositswithorassociatedwith
Hilton and Bateman, 2006). If the callipterids prove to be a natural indicatorsofseasonality(e.g.,Feldmanetal.,2005),arestrongevidence
oftheirpreferenceforseasonallydrysettings.
AsKerp(2000)hasnoted,callipteridsoccuronlyoccasionallywith
⁎ Correspondingauthorat:DepartmentofPaleobiologyMRC-121,NMNHSmithsonian conifers(ChaneyandDiMichele,2007;GaltierandBroutin,2008),anoth-
Institution,Washington,DC20560,USA.Tel.:[phone];fax:[phone].
ergroupconsideredtofavorseasonallydryhabitats.Fossilsofthetwo
E-mailaddresses:[email protected](W.A.DiMichele),[email protected](H.Kerp),
groupslargelyarefoundseparately,evenwithinrocksequencesfrom
[email protected](R.Sirmons),[email protected](N.Fedorko),[email protected]
(V.Skema),[email protected](B.M.Blake),[email protected](C.B.Cecil). whichbothgroupsotherwiseareknown(e.g.,KerpandFichter,1985),
0166-5162/$–seefrontmatter.PublishedbyElsevierB.V.
http://dx.doi.org/10.1016/j.coal.2013.07.025
Author's Personal Copy
W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78 57
suggesting different habitat preferences and, unsurprisingly, environ- 1994).Tousetheseflorasforaccuratebiostratigraphicdeterminations,
mentalheterogeneityandcomplexityinseasonallydrylandscapes. onemustbedealingwithbiome-restrictedassemblageswhereinevolu-
Theearlydevelopmentofflorasfromseasonallydrylandscapesis tionary changes can be identified and tracked through time with
poorlyknown,however,largelyduetohydrologicalfactorsrelatedto high precision and accuracy (for discussion see Broutin et al., 1990;
thepreservationoforganicmatter.Themostlikelytimesforfossilfor- DiMichele and Aronson, 1992; DiMichele et al., 2008; Kerp, 1996;
mationinbasinallowlandsarewhenconditionsforplantpreservation MapesandGastaldo,1986).Unfortunately,theseasonally-dryassem-
favor both short-term and long-term burial (Gastaldo and Demko, blagesofthepre-Permianareinadequatelyknownatpresentforthis
2010). Increasing evidence indicates that during the Pennsylvanian, task.Theirsporadicappearanceswithinstratigraphicsequencesother-
thesefavorableperiodswereduringwettestpartsofglacial–interglacial wisedominatedbythewetlandbiomeareindicationsofclimateoscilla-
cycles,whichinequatoriallatitudesmainlyoccurredduringthemiddle tion,shiftingspeciespoolsandpreservationalhappenstance,butthese
andlatestagesofglacialmaxima,whensealevelswereattheirlowest occurrences are too few for detailed reconstruction of evolutionary
(Ceciletal.,2003;Hortonetal.,2012;PeyserandPoulsen,2008).This changes.
assuredbothshort-termburialoforganicmatterunderrainfall-driven TheDunkardflorahasbeenwidelycollectedandmanyofitscom-
highwatertables,andintermediate-termburialundersubsequentlyris- monelementshavebeenillustrated.However,therearefewillustra-
ingsealevels,duringensuinginterglacials(ElrickandNelson,2010). tionsofthecallipterids.TheoriginalFontaineandWhite(1880,Plate
Ultimatelong-termburialreliedoncontinualbasinalsubsidence,anas- XI,Figs.1–4)figureswereengravings,andlackfinedetail.Photographic
sumptionmadeplausiblebyrecent“digital”correlations,indicatingthat illustrationsofcallipteridspecimensappearinDarrah(1975,Figs.1–3),
glacial-interglacialcyclescanbecorrelatedwithhighfidelityfromthe Gillespieetal.(1975,PlateIAandPlateVIIIA;refiguredinBlakeetal.,
MidcontinentUSA,throughtheeasternNorthAmericancoalbasins,to 2002, Plate XXXV, Figs. 1–2, 6) and Gillespie and Pfefferkorn (1979,
as far as the Donets Basin of the Ukraine (Eros et al., 2012; Falcon- Plate3,Figs.6–8;refiguredinBlakeetal.,2002,PlateXXXV,Figs.5,7).
Langetal.,2011a;Heckeletal.,2007).Therealsoisevidenceindicating Consequently,themainobjectiveofthispaperistodescribeandillus-
thatseasonallydryflorasoccurredinbasinsregularlyduringmuchof tratetheDunkardGroupcallipteridsanddetailtheirstratigraphicdistri-
theMiddle and Late Pennsylvanian(Falcon-Langet al., 2009, 2011b; bution.Someofthesespecimenscomefrom previously unillustrated
Plotnick et al., 2009), but mainly during those intervals of climate collections made by David White in 1902, and T.E. Williard in 1903
andsea-levelcycleswhenclimatewasseasonallydrier—duringglacial (housedattheNationalMuseumofNaturalHistory),andbyAurealT.
minima/marine highstand through early glacial maxima/lowstand, Cross(housedattheFieldMuseumofNaturalHistory),whoworkedex-
thus when the potential for both short-term and intermediate-term tensivelyintheDunkardinthelate1940sandearly1950s.Inaddition,
burialand preservation wereattheirlowest.Callipterid andconifer- weillustrateaspecimenofA.confertafromthecollectionsofR.D.Lacoe,
richflorasdidnotbegintobepreservedregularly,orbecomethemost whichheacquiredinthelate1800sandsenttotheNationalMuseum
common floras in lowland basins until the most favorable times for of Natural History as part of the transfer of his collection to the
preservation–thewettesttimesofagivenglacial–interglacialcycle– Smithsonian in the mid-1890s; this specimen is of significance
themselvesbecamerelativelyseasonallydry.Thisoccurredduringthe because itmaybetheoldestsurvivingDunkardcallipteridspecimen
later Pennsylvanian and Permian, depending on location within the “incaptivity”.
Pangeantropics(TaborandPoulsen,2008). Basedonthisstudy,threecallipteridgeneraandfourspeciesoccurin
This digression into callipterid ecological and preservational pat- rocks of the Dunkard Group: Autunia conferta (Sternberg) Kerp, A.
ternsisimportant for understandingcontroversiessurroundingtheir naumannii (Gutbier) Kerp, Lodevia oxydata (Goeppert) Kerp and
importance in the biostratigraphic zonation of terrestrial sequences Haubold,andRhachiphyllumschenkiiKerp.
andtheconsequencesofthisforthedebateabouttheageoftheDun-
kardGroup.Themostwidespreadcallipteridspecies,Autunia(formerly
Callipteris)conferta(Kerp,2000)waslongconsideredanindexspecies 2.GeologyoftheDunkardGroup
forthebaseofthePermian(seeextensivediscussionsinvariouspapers
inBarlow,1975).Consequently,itsdiscoveryinDunkardrocks,incom- 2.1.Stratigraphy
binationwithotherunusualelements,ledFontaineandWhite(1880)to
proposethattheDunkardGroupwasatleastpartially,ifnotentirely,of Inthisstudy,wefollowtheterminologyusedbytheFedorkoand
Permianage.DavidWhite,oftheU.S.GeologicalSurvey,thoughinitially Skema (2013), which divides the Dunkard into the Washington and
infavorofapartialPermianage(White,1904),ultimatelycametoagree GreeneFormations(Fig.1).Martin(1998)summarizesthehistoryof
(White,1936)thattheentireDunkardGroupwasofPermianage,apo- Dunkard stratigraphic nomenclature. The Washington Formation, at
sitionlongassertedbyI.C.White(seediscussioninLyonsandWagner, the base of the Dunkard, encompasses those rocks from the top of
1995).Throughthe20thcentury,theageoftheserockscontinuedtoat- theWaynesburgcoaltothebaseofthetopoftheUpperWashington
tractattentionandcontroversy(e.g.,Clendening,1972;Clendeningand Limestone.TheGreeneFormationencompassesallrocksabovethetop
Gillespie, 1972; Cross, 1954, 1958; Cross et al., 1950; Darrah, 1975; oftheUpperWashingtonLimestone,andisthickerthanWashington
Bode,recordedinthediscussionfollowingthepaperbyGillespieetal., formation.
1975;Martin,1998),withthecallipteridsplayingamajorpart. TheDunkardGroupisanerosionalremnantthatcropsoutinsouth-
Whatisclear,however,isthatthecallipterids,andthepeltasperms westernPennsylvania,easternOhio,centralandwesternWestVirginia,
ingeneral,arefaciesfossils.Theirappearanceinageologicalsectionre- andpossiblyinsmalloutliersinwesternMaryland.Itreachesamaxi-
flectsseasonallydryclimaticconditions.Callipterids,conifersandava- mumthicknessinthePittsburgh–HuntingtonSynclinoriumofapproxi-
rietyofotherplantsnottypicallyencounteredinPennsylvaniantropical mately340minGreeneCounty,Pennsylvania,andadjacentpartsof
wetlandassemblages,nonethelessoccurinthePennsylvanianlowlands WetzelCounty,WestVirginia.TheDunkardconsistsofcyclicsucces-
andevenlatestMississippian,thoughnotmixedwithwetlandspecies sions of sandstone, shale and mudrocks, and limestone with minor
(e.g., Aizenverg et al., 1975; Augusta, 1937; Bassler, 1916; Boyarina, coal(Beerbower,1961),thelatterparticularlyinthethickerlithological
2010; Cridland and Morris, 1963; Doubinger, 1979; Doubinger and section,tothenorthandeast.Heretheclasticstrataarelargelybuffand
Langiaux,1982;Doubingeretal.,1995;Falcon-Langetal.,2009;Galtier grayincolorintheWashingtonformation,withminorredbeds,which
etal.,1992;Havlena,1958;Hernandez-Castilloetal.,2001;Langiaux, becomemoreconspicuoushigherinthesection,inconjunctionwithde-
1984; Lyons and Darrah, 1989; Martino and Blake, 2001; Němejc, creased abundances of coal(Fedorko and Skema, 2013). Toward the
1951;Plotnicketal.,2009;Rothwelletal.,1997,2005;Šimůnekand south and southwest, the Dunkard section becomes increasingly red
Martínek, 2008; Wagner and Lyons, 1997; Winston, 1983; Zhou, and is mostly a sequence of stacked paleosols interbedded with
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58 W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78
Fig.1.DunkardStratigraphy,afterFedorkoandSkema(2013).Numbersindicatehorizonsfromwhichcallipteridshavebeenidentified.1.BetweentheWaynesburgAandWashington
coals.2.WithinorabovetheWashingtoncoalzone.3.WithinorproximatetotheLowerandMiddleWashingtonlimestones.4.IntheintervalfromtheJollytowncoaltotheDunkard
coal.5.NeartheNinevehcoal.
channel-formsandstonebodies(Berryhill,1963;FedorkoandSkema, characteristic of the latest Pennsylvanian (Gzhelian), quantitatively
2013;Martin,1998). dominatedbymarattialeantreeferns(Blakeetal.,2002;Darrah,1975;
It is near the “Washington coal complex”, in the middle of the Gillespieetal.,1975;WagnerandLyons,1997).Therearealsosome
Washington Formation (Skema, 2011), from which the first Appala- taxathat,inEurope,hadbeenconsideredcharacteristicoftheMiddle
chian basin callipterids are confidently reported. The base of the Pennsylvanian, specifically the pteridosperms Neuropteris ovata and
WashingtoncoalcomplexisplacedatthebaseoftheLittleWashington Macroneuropteris scheuchzeri (see discussion in Darrah, 1975). Thse
coal (Hennen, 1911), below which is a regionally extensive paleosol formshavebeenshowntorangethroughouttheUpperPennsylvanian
(FedorkoandSkema,2013).TheWashingtoncoalcomplexconsistsof (Blakeetal.,2002)andintothePermianinNorthAmerica.
twotofourcoalbedsseparatedbyshaleand/orsandstone.Inthenorth- Dunkardcallipteridsdonotoccuraspartofthewetlandbiofacies,
westernpartoftheDunkardoutcroparea(BelmontCounty,Ohioand even though some callipterids may have preferred wetter, even
MarshallCounty,WestVirginia)thecomplexconsistsoftwocoalbeds swampysubstratesinseasonallydrylandscapes(BarthelandRößler,
separatedbyN2mofgrayshale,depositedunderbrackishconditions. 1996;KerpandFichter,1985).Theyarewelldocumentedfirstinshales
Theshalebedcontainsabrackishfauna,includinglinguloidbrachiopods withintheWashingtonFormation,beginningattheapproximatehori-
and myalinid pelecypods (Berryhill, 1963; Cross and Schemel, 1956; zon of the Washington coal complex, and continuing into the lower
FedorkoandSkema,2013).Thisfaunaisthestratigraphicallyhighest halfoftheGreeneFormation.Thesefossilsoccurinavarietyoflitholo-
occurrenceofanyevidenceofmarineinfluencefoundintheAppala- gies,fromdark,micaceous,finelylaminatedshales,tobuffandredmud-
chianBasinandmaycorrelatewithaglobalmarinetransgressionand stoneswithpoorfissility,tolimestones.Darrah(1975,inthecaptionsto
highstandjustbelowtheboundaryofthePennsylvanianandPermian hisFigs.1and3onpage95)providestheonlyreportofcallipteridsfrom
(Davydovetal.,2010,2013). belowtheleveloftheWashingtoncoalcomplex.Heattributesthecol-
lectionstoJamesBarlowoftheWestVirginiaGeologicalSurvey,pur-
2.2.Plantfossilsingeologiccontext portedly collected from the lower Washington Formation, between
the Waynesburg A and Washington coals, near Williamstown, in
Most Dunkard plant fossils have been collected from the coal- WoodCounty,WestVirginia.However,coalsareverypoorlydeveloped
bearingportions,frequentlyfromshalesimmediatelyabovecoalbeds. intheDunkardGroupinWoodCounty,andDarrahneitherprovidesde-
Thus,theyarecomposedoftypicalPennsylvanianwetlandplants.This tailedinformationonthelocationofthecollectinglocalitynorontheul-
wetland flora is quite widespread, however, and has been found timatedispositionofthesamples;atpresent,wetreatthisreportwith
throughouttheoutcroparea,includingintheredbedfacies(Blakeand reservation.Callipteridshavebeendescribedfromtheimmediateroof
Gillespie, 2011). The flora is diverse and includes many species shalesofacoalbedatonlyoneplace,theBrown'sBridgelocality,by
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W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78 59
FontaineandWhite(1880),andheretheymayactuallyhaveoccurred respectively), specifically noting that they come from the roof shale
in a clastic layer at the base of the Lower Washington Limestone oftheWashingtoncoal.LeoLesquereuxidentifiedaspecimeninthe
(White,1891). R.D.Lacoecollection(USNMspecimen27141)as“C.conferta”,according
Otherplantstypical(butnotdiagnostic)ofPermian-ageflorashave to a label affixed to the specimen; a further label identifies it as
beenreportedfromtheDunkardandolderrocksin theAppalachian comingfrom“Brown'sMills”,andgivesthestratigraphichorizononly
Basin including Taeniopteris, Plagiozamites, and conifers (Blake and as“Washingtoncoal”.OnAugust12,1902,D.WhitecollectedA.conferta
Gillespie, 2011), including one collection from near the base of the andL.oxydatafromalocalityheidentifiedas“Brown'sMillsonDunkard
Upper Pennsylvanian (McComas, 1988; Wagner and Lyons, 1997). Creek,MonongaliaCo.,W.Va.”(USGSlocality2926);intheUSGSlocality
These are reported from various horizons, including the Cassville register,collection2926isnotedascomingfrom“justoverthelime-
Shale,abovetheWaynesburgcoal,atthebaseoftheDunkardGroup stoneabovetheWashingtoncoal”.
(Darrah,1975;FontaineandWhite,1880;White,1904,1936).Theseoc- From the mid-20th century onward, all of these collections have
currences have led some paleobotanists to conclude that the entire beentreatedashavingbeencollectedfromthesameplaceandstratum.
DunkardGroupisofPermianage. Detailed notes in published papers and official files (field notes and
locality registers), however, indicate that Fontaine and I.C. White's
3.CallipteridsinDunkardstrata “Brown's Bridge” may, in fact, represent a different site from the
“Brown'sMills”localityofDavidWhiteandR.D.Lacoe.Inhis1891re-
InthisreportweillustrateDunkardcallipteridsfromanumberof port on the bituminous coal fields of Pennsylvania, Ohio and West
stratigraphicpositions(Fig.1)andgeographiclocations(shownregion- Virginia,I.C.White(1891,p.37–38)specificallydifferentiates“Brown's
allyinFig.2;morespecificityisshowninadditionalmapsthatfollow). Mills”from“Brown'sBridge”,notingthatitisfromthesecondlocation
Wefocushereonthefollowing:(1)Collectionsofcallipteridsinthe thatcallipteridsweredescribedinReportPP,SecondGeologicalSurvey,
National Museum of Natural History, made by David White or T.E. Pennsylvania,p.54(FontaineandWhite,1880).Hegoesonfurtherto
Williard, or acquired from R.D. Lacoe; (2) Collections from the Field notethatatBrown'sMillstheWashingtoncoal(acomplexsuccession
MuseumofNaturalHistory,madebyAurealCross;(3)Specimensillus- ofcoal,shaleandbituminousshale)hasa limestoneroof,theLower
tratedordescribedexplicitlyinpreviouspublications.Preciseidentifica- WashingtonLimestone,lyingimmediatelyabovetheuppermostbitu-
tionofthecollectinghorizonsfromwhichthesecollectionsweremade minousshale.Thelimestoneisnotedascontainingmuchiron.Healso
is often difficult. When the original work was being done, the area notesthattheLowerWashingtonLimestoneisofteninterbeddedwith
hadbeenclearcutandconsistedlargelyofsmallfarms.Infrastructure iron-rich layers that are themselves interstratified with bituminous
suchasroadsandshortlinerailroadswerebeingactivelyconstructed. shales,thelatter“coveredwithfossilplants”.I.C.White(1891)specifi-
Todaythisareaisgenerallyremoteandreforested. cally writes that it was also on such a layer that callipterids were
foundatBrown'sBridge.
Theseobservationsappeartoestablish,unequivocally,that(1)the
3.1.Brown'sBridge,Brown'sMills,Worley
callipteridsreported byFontaineandWhite(1880)are from a place
knownthenas“Brown'sBridge”,(2)thatthisoriginalsiteisdifferent
ThereissomeconfusionsurroundingthesitefromwhichDunkard
fromthesitedescribedas“Brown'sMills”,and(3)thatcallipteridsat
Groupcallipteridswereoriginallycollected.Forthisreason,wedevote
bothplacescamefrombituminousshalelayers,whichwerevariously
severalparagraphstothismatter.Theoriginalbedshavenotbeenre-
developedaspartoftheLowerWashingtonLimestone.
locatedanduncertaintyexistsabouttheexactsitesandstratigraphic
Alsobearingonthismatterarethedescriptionsofthefossiliferous
positions at which the original 19th century and subsequent early
beds in relation to the Washington coal complex. Fontaine and I.C.
20thcenturycollectionsweremade.
WhitereportedcallipteridspecimensatBrown'sBridgefromtheroof
Fontaine and White (1880) reported Callipteris (Autunia) conferta
shale of the Washington coal. In contrast, David White reported his
and Sphenopteris coreacea (L.oxydata) from a locality theyidentified
specimensascomingfromjustoverthelimestoneabovetheWashing-
as “near Brown's Bridge, Monongalia Co., W. Va.” (p. 42 and p. 54,
toncoal,thusnotfromashaleimmediatelyincontactwithacoalbed.
TheprovenanceoftheUSNMLacoe-collectionspecimenisequivocal
becauseLacoeprimarilyacquiredmaterialthroughpurchase,exchange,
orbyhiringcollectorstovisitparticularsites.Itispossiblethatthespec-
imenwasacquiredfromFontaineandI.C.White(alongwithalarger
collectionofDunkardspecimensnowhousedintheNMNH,donated
byLacoe).Alabelaffixedtothisspecimenliststhesiteofcollectionas
“Brown's Mills”. The matrix of the Lacoe specimen, which is heavy,
12 andthuspresumablyenrichediniron,issimilarincolorandtexture
10 to that of D. White's Brown's Mills specimens. These are the only
5 9 callipteridsintheNMNHcollectionsfromdarkgray,organic-richshales,
8 321 andtheyaresimilarenoughtoinferanoriginfromthesamebed.Lacoe
647 must have acquired this specimen prior to the 1889 death of Leo
Lesquereux(whoidentifiedit),andturneditovertotheSmithsonian
11 aspartofthe1895donationofthebulkofhisprivatecollection.David
White, who arranged, packed and identified the specimens in the
13 Lacoe bequest, thus would have known of this specimen and the
Brown'sMillslocalitypriortohis1902fieldworkintheDunkard.
Finallythereareavarietyofother,indirectlinesofevidencethatsug-
Fig.2.DunkardGroupoutcropareaandlocationofcallipteridcollections.Appalachian gest different sites for Brown's Bridge and Brown's Mills (Fig. 3).
BasinProvince(DarkGreen),AppalachianPlateauregion(LightGreen),Dunkardbasin Accordingtohis1902,Pennsylvania–Dunkardfieldnotebook(onfileat
(withinredline).1,Brown'sBridge.2,Brown'sMills.3,WestofLittleton.4,Between theNMNH),onAugust10,1902DavidWhitecollectedatCore'sMine
pumpingstationwestofLittletonandLittleton.5,EastofBelltonStation.6,RinehartTun- onDoll'sRun(USGS2893—roofoftheWashingtoncoal,nocallipterids
nelStation.7,WestofWallaceStation.8,Winkler'sMill.9,PleasantHillGap.10,Locations
aroundWaynesburg.11,Williamstown.12,Wolfdale.13,Liberty.ModifiedfromMilici collected),whichwepresumeto havebeenlocatednearpresentday
andSwezey(2006,Fig.3). Core, West Virginia, south of Dunkard Creek. On August 11, 1902 he
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60 W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78
Fig.3.Blacksville,WV1904USGS15′topographicmapsegmentshowingthelocationsoftheBrownsMills(2926)andBrown'sBridge(2921)sitesinWestVirginia.Notethespellingof
thesenames.Thereisambiguityinfieldnotes,localityregisters,theliteratureandtheUSGSGeographicNamesInformationSystemregardingthespellingof“Brown's”vs“Browns”for
bothBrownsMills(theofficialUSGSspelling)andBrown'sBridge,aswellasBrownsHill,abovetheBrown'sBridgesite.Wehavesplitthedifference.
collectedatasitehedesignatedBrown'sBridge(USGS2921—beneath USGStopographicmapdoesnotshowarailroad.If,indeed,therailroad
the Washington coal, no callipterids collected), which in his notes is werebuiltafterthecollectionsofLacoeandDavidWhiteweremade,
showntobeanunspecifieddistancenorthofabridgeoverDoll'sRun, thentheoriginalbedsmayhavebeenburiedorsignificantlyalteredin
northofCore.Onthe1904topographic map,abridgeis shownover outcrop.Thismayaccountfortheinabilityoflatercollectorstorelocate
Doll's Run 1.5 miles (2.4km) north of Core, and a second bridge is anyoftheseearlycollectinghorizons.
shownoverDunkardCreek,0.5miles(0.8km)northoftheDoll'sRun
bridge. On the 1904 topographic map, this second bridge carries the 3.1.1.FontaineandI.C.WhiteCollection
roadthatleadstoMt.Morris,Pennsylvania;furthermore,immediately TheentireoriginalDunkardcollectionofFontaineandWhite(1880)
tothenorthofthebridge,onthePennsylvania–WestVirginiaborder,is hasbeenlost.Consequently,theirillustrations–allengravingsandof
aprominencelabeled“Brown'sHill”.OnAugust12,1902,Whitecollect- variabledetail–areallthatremain,whichhascausedsignificantprob-
ednearMt.Morris(USGS2894—beneaththeWaynesburgSandstone, lemswithapplicationofsomeofthetaxonomicnamestheyinstituted.
no callipterids collected) and then at the site he called Brown's Mills In their original publication, they illustrated two callipterid species,
(USGS2926–justoverthelimestoneabovetheWashingtoncoal,his only one of which they recognized as a callipterid, Callipteris (now
callipteridcollection,accordingtotheUSGSlocalityregister–thereare Autunia)conferta(F&WPlateXI,Figs.1–4,reproducedasFig.4aof
no D. White field notes accompanying this collection). In 1903, T.E. this paper). The other, which we identify as L. oxydata (Goeppert)
Williardobservedthathiscollection,USGS3438(nocallipterids),was Kerp and Haubold, 1988, was originally described as Sphenopteris
fromthe“southsideofDunkardCreekoppositethemillatWorley”.The coreacea Fontaine and White (F & W Plate 5, Fig. 5, reproduced as
U.S. Geological Survey Names Information System (http://geonames. Fig. 4b of this paper), which Darrah (1969) identified as Callipteris
usgs.gov/pls/gnispublic/f?p=132:3:1293502122222994::NO:3:P3_FID, lyratifolia. Fontaine and White (1880, p. 54) describe their plants as
P3_TITLE:1549998,Worley)shows“Brown'sMills”tobeanalternative coming from a “calcareous iron ore” that occurs in the roof of the
namefor“Worley”.TheWorley/Brown'sMillssiteis1.5(straightline) Washingtoncoal.
to2miles(roadalongDunkardCreek)(~2.5–3km)westofthe“Brown's
Bridge”location,butWorley/Brown'sMillsalsoisonDunkardCreekand 3.1.2.R.D.Lacoespecimen
directlyoppositeabridge. ThereisasinglespecimenofA.confertamentionedabove,fromthe
Itappearsfromthisdiscussionthatasitecalled“Brown'sMills”can R.D.Lacoecollection,housedattheNationalMuseumofNaturalHistory
beconfidentlylocatedonthesouthsideofabendinDunkardCreek (USNMspecimen27141—Fig.5).ThespecimenwasidentifiedasC.
(NWquadrantoftheBlacksville15′Quadranglemap,andNEquadrant conferta by Leo Lesquereux (according to a label affixed to it); it is
oftheBlacksville7.5′Quadranglemap),oppositetheunincorporated mostlikelythatthisspecimenwasmadeavailabletoLesquereuxfor
townofWorley,alongpresent-dayWestVirginiaRoute7.Weinitially identificationbyLacoe(seenoteinDarrah,1969,p.153).Thespecimen
believedtheBrown'sMillscollectionstocomefromclosetothegrade isinaheavy,thinbedded,darkgrayshalethat,fromitsweight,mustin-
ofaformerrailroadatthatlocation.However,thecontemporary,1904 deedcontainconsiderablesiderite.
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W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78 61
Fig.4.OriginalillustrationsofcallipteridsbyFontaineandWhite(1880),fromBrown'sBridge,WestVirginia.A.Autunia(Callipteris)conferta.OriginalPlateXI,Figs.1–4.B.Lodeviaoxydata
(Sphenopteriscoreacea).OriginalPlateV,Fig.5.
TheidentificationofthisspecimenasA.confertaissupportedbythe fromshalesabovethelimestoneimmediatelyabovetheWashington
blunttipped,rectangularpinnuleshapes,sunkenmidveinsandassoci- coal.
atedvaultedpinnulelaminaeandsteeplateralveins.Preservation of Aspreviouslymentioned,theBrown'sMillsgeologicaldescriptionis
thespecimenisnotgood,butthismayreflectitsageandthefactthat at odds with the Brown's Bridge description of Fontaine and White
it has been coated in the past, probably with a varnish, to preserve (1880),whoreportedtheirplantbedtobetheroofoftheWashington
whatmayhavebeentheflakingorganiccompression. coal.DarrahreportsthatherecollectedfromtheBrown'sMillssitein
1932,butdoesnotillustrateitorprovideageologicalinterpretivesec-
tion; he described the plant bed as a thin, dense, arenaceous shale,
3.1.3.DavidWhitecollection whichbroadlyfitstheotherknowncollections,buthedoesnotmention
DavidWhite's“Brown'sMills”collection(USGSlocality2926)con- theconspicuouslydarkcolor.
tains both A. conferta (Fig. 6) and L. oxydata (Fig. 7), the same taxa Environmental interpretation of the callipterid-bearing beds at
reportedfromBrown'sBridgebyFontaineandWhite(1880).Thema- Brown'sMillsisdifficult,basedonthefragmentaryevidenceavailable.
trixofthespecimensdiffersslightlyfromthatofthesingleSmithsonian Furthermore,thesiteispresentlyheavilyvegetatedand,thus,toopoor-
Lacoespecimen,mainlyinbeinglesssideriticandmoredistinctlylami- lyexposedtopermitlocationoftheoriginalbeds.I.C.White(1891),
nated,butbothareverydarkshaleswithconsiderablesideritecontent, however, described a complex section at the Brown's Mills site and
sotheymayrepresentdifferentpartsofordifferentcollectinglocalities noted that plants occur in layers of bituminous shales within the
withinthesamebed.DavidWhite's1902fieldnotes,frustratingly,do Lower Washington Limestone. The co-occurrence of large, well pre-
notmentionthislocalitybyname.Theonlyrecord,therefore,isinthe servedfragmentsofA.confertaandL.oxydatatogetheronsomebedding
USGeologicalSurveypaleobotanicallocalityregisterentry,whichprob- surfaces,inthesamelithology,leaveslittlequestionthatthesespecies
ably was based on data included with the specimens when shipped werelivingtogether,atleastintheorganic-shalehabitat.Thesedark-
from the field. The locality register notes that the collections come shale, callipterid beds also include a fauna of ostracodes and snails
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62 W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78
Fig.5.R.D.LacoeCollectionspecimenfromBrown'sMills,WestVirginia,identifiedbyLeoLesquereux.Autuniaconferta.USNMspecimen27141.Specimenhasbeencoatedwithan
unidentifiedsubstance.A.Typicalsmall-pinnuledformofAutuniaconferta.B.MagnificationofpinnaefromA,illustratingattachmenttomainrachisandpinnulecharacteristics,upswept
venation.Scalebars=1cm.
(Tibertetal.,2011).Thesnailsareheavilycalcifiedandwouldhavere- 3.2.WestofLittleton
quiredalkaline-richwatersheds,thustheydidnotlikelyliveinassocia-
tionwiththedrowningofanacidic,peat-formingswamp.Thegeneral Several plant collections from “West of Littleton”, West Virginia,
inferenceisthatthelimestoneandtheinterbeddedshalesweredepos- weremadebyDavidWhiteonAugust22,1902.AccordingtoWhite's
itedunderaseasonallydryclimate(N.Tibert,personalcommunication, fieldnotesandanotefoundwiththecollections,thesitewasatthe
2013). westendofthefirstrailroadcutwestofLittleton.Therailroad,then
We may draw the following conclusions from these observations. theBaltimoreandOhioline,isnowgone,butappearsontheNEquad-
(1)Thestratigraphic-temporalseparationofthecallipteridbedsfrom rantoftheLittleton15′USGSquadranglemapfromtheearly20thcen-
theWashington coal complex indicatesthattheywere notdeposited tury(Fig.8).T.E.Williardcollectedfromthesesameexposuresin1903
bydrowningofthecoalswamp.(2)Thisplantbedcontainsabundantre- andnotedthemascomingfromthefirstrailroadcutnorthofLittleton,
mainsofnon-marineostracodes,snails,fishandserpulidworms(Tibert justaboveFishCreek.Duetothepathoftherailroadtrack,,thesiteis,in
etal.,2011),suggestingthatitmaybeaninterbedfaciesoftheLower fact,northandwestofLittleton.
WashingtonLimestone,whichmayexplaintheironcarbonatecontent TheWest/NorthofLittletonplantcollections(USGSLocalityNumbers
oftheshales.(3)Thepositionoftheplant-bearingshaleabove,orper- 2909,2909×,2911,3376)consistofseveraldifferentlithologies.D.White
hapsevenwithin,apartingofalimestonereflectsashiftfromahumid indicatesplantsatminimallyfourlevels,whichmayaccountforhislitho-
climate during coal-swamp development to a sub-humid, seasonally logically mixedsamples—there are fewerUSNMcollectionsthanthe
dryclimate(terminologyofCecilandDulong,2003)duringdeposition number of plant-bearing beds indicated in the field notes, indicating
ofthenon-marinelimestoneandorganic-richshaleinterbeds.(4)The mixingofcollectionsmadefromthevarious,distinctfossiliferousbeds.
density, lack of preferential orientation and excellent preservation of Similarly,Williard'ssamplesarelithologicallyheterogeneous,indicating
theplantmaterialsuggestaparautochthonoustoautochthonousenvi- derivation from more than one fossiliferous bed. D. White's notes for
ronmentofaccumulation—thefoliagewasburiedwhereitfellfrom thislocationindicatearelativelylargenumberoflimestonesinthesec-
theparentplant.(5)Atthe landscapescale, the reportofcallipterids tion,interspersedwithredandgreenshale.Thestratigraphicpositionof
fromsandstonesatthissite(Gillespieetal.,1975)isancillaryevidence thesebedsappearstobebetweentheJollytownandDunkardcoals(be-
that callipterids were widespread and occurred across the landscape tween which the Tenmile coal occurs, Fig. 1), with some uncertainty.
foranextendedperiod,permittingtheirpreservationinavarietyofhab- ThispositionwouldputthecollectionsinthelowerGreeneFormation,
itatsandthelithologiesformedtherein. atvariousdistancesabovetheUpperWashingtonLimestone.
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W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78 63
Fig.6.AutuniaconfertafromBrown'sMills,WestVirginia,collectedbyDavidWhite.USGSlocality2926.A.USNMspecimen543957,fragmentaryfrondwithseveralpinnae.B.3Xenlarge-
mentofA,notepinnuleshape,whichisthesameasthatoftheLacoe/LesquereuxspecimenandthoseillustratedbyFontaineandWhite(1880)fromBrown'sBridge.Thicknessofpinnule
laminaeobscuressteeplyascendinglateralveins.C.USNMspecimen543962,pinnatipwithacroscopicallyfusedpinnules,steeplyascendinglateralveins.BandCatsamemagnification.
Scalebars=1cm.
Collections2909,2909×and3376aremostlyhandsamplesofgrayto basedonthepresenceofslickensides,bioturbatedtexture,andlackof
redclay-richmudstoneswithafewbuffsiltstones.Themajorityoftheas- clearbedding.Wewouldcharacterizeallthesecallipteridspecimensas
semblageineachcollectionconsistsalmostentirelyoftypicalLatePenn- A.conferta(Fig.9A–C),basedonthehighvaultingofthepinnules,sunken
sylvanian wetland plants, including Pecopteris tree-fern foliage, midveins,anddense,steepsecondaryveins.TheD.Whiteandsomeofthe
calamitalean remains and possibly Callipteridium. There are, however, Williardcallipteridcollectionsmayhavecomefromthesamebed,based
severalspecimensofcallipteridsinthesecollections,preservedingray onthesimilarityoftheirrespectivelithologies.However,theWilliardcol-
toredmudstonesthatappeartohavebeenpedogenicallyoverprinted, lectionincludesaspecimeninbuffsiltstone.
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64 W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78
Fig.7.LodeviaoxydatafromBrown'sMills,WestVirginia,collectedbyDavidWhite.USGSlocality2926;USNMspecimen543958.A.Fragmentoffrondwithattachedpinnae.B.3×enlarge-
mentofA,notepinnuleshape,steeplyascendinglateralvenation,andthickpinnulelaminae.C.Closeupoftwopinnae.Notespirorbidsattachedtothefoliage(oneatwhitearrow,others
canbeseenbyscanningthefoliagelaminae).Scalebars=1cm.
Collection2911alsoconsistsofamixtureoflithologies,includingred tunnel along the railroad grade. No pumping station is shown north
mudstonesandbuff,micaceoussiltstone.Asinglepossiblecallipteridis andwestofLittletononthe1926USGS15′topographicmap(Fig.8).
presentinthiscollectioninthebuffsiltstonefacies.Thespecimenmost Thespecimensfromthissiteareamixtureoflithologiessuggesting
closelyresemblesRhachiphylluminthepresenceofflatpinnulelaminae, that they were collected from different beds. Most of the specimens
relativelysparseveins,andathin,non-sunkenpinnulemidvein. are red mudstone, consisting mainly of wetland taxa such as
Basedonthemixednatureofthecollections,onthesmallamountof Macroneuropteris scheuchzeri, Polymorphopteris, Pecopteris and
overlapbetweenthecallipteridsandwetlandspecies,andontheuncer- Sphenophyllum.However,severalpinnaeofA.confertaoccurinagray,
taintyinthefieldnotesthataccompanythecollections,littlecanbesaid carbonate-rich, fine grained mudstone, on an irregular red-stained
aboutthepaleoenvironmentsoccupiedbytheseplantsoraboutthecli- surface.Thepinnulesarevaultedwithasunkenmidveinandsteeply
maticregimeunderwhichtheylived. angledlateralveins(Fig.9D,E).
D.White(fieldnotes)placesthiscollectionatthelevelofacoalho-
rizonbetweentheJollytowncoalandtheDunkardcoal(notedas“fide
3.3.BetweenLittletonandthePumpingStationWestofLittleton I.C.W.”—presumablyreferringtoI.C.White).IfD.Whiteinterpreted
thesectioncorrectly,thesecollectionsappeartobefromasuccession
USGSLocality2901isanunspecifieddistancetothewestoftheLittle- ofthincarbonatebedsandredshalebelowabedofcoalandcarbona-
tonrailroadstation(accordingtoD.White'sfieldnotes),butperhaps¼ ceous shale, above the Jollytown coal, making the Tenmile coal a
or less of the distance between Littleton and the Board Tree railroad candidate.
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W.A.DiMicheleetal./InternationalJournalofCoalGeology119(2013)56–78 65
Fig.8.Cameron,WV1904andLittleton,WV1926USGS15′topographicmapsegmentsshowingfossilplantlocalitiesfromWestofLittleton(2909and2911),NorthofLittleton(3376)and
BetweenLittletonandthePumpingStationWestofLittleton(2901).Fossilplantlocality2mileseastofBellton(2914).AllinWestVirginia.
3.4.TwoMilesEastofBelltonStation asinglespecimenwithcallipteridimpressionsinthiscollection;itcon-
tainspartsoftwopinnae,preservedinahard,buff,siltstone.Theyare
Along the former Baltimore and Ohio Railroad, two miles east of referable to A. conferta based on pinnule shape, sunken midveins,
Bellton,WestVirginia(Fig.8),D.Whitecollectedspecimensfromred steeplateralveinsandvaultedpinnulesurfaces(Fig.10).
andgrayshales,anunspecifieddistanceabovewhatheidentifiedas
the “Dunkard (or perhaps the Jollytown) coal” (field notes), which 3.5.RinehartTunnelStation
wouldplacethiscollection(USGSLocalitynumber2914)inthelower
portion of the Greene Formation. The coal is noted as 6 in. (15cm) On August 23, 1902, the final day of his summer field season,
thick.RedbedslieabovetheDunkardcoal(Fig.1),separatedfromit D.WhitestoppednearanewlyexcavatedrailroadtunnelontheWest
bygrayshalesandsandstone,whichisbroadlyinconformancewith VirginiaShortlineRailroad(fieldnotespage34),asitehereferredto
D. White's field sketch, perhaps explaining his identification of the as“TunnelSta.”(?TunnelStation).Apossiblylateradditiontothenote-
coal bed. From White's notes, it appears that the plant-bearing beds bookbyD.Whiteoranunknownpersonlocatesthissite“…inSEcorner
areseparatedfromthecoalbymorethanameterbutlessthan10m. ofWetzelCountyinCenterpoint15′quadandFolsom71/2′quad.Itis
Consisting,again,ofmixedlithologiesandamixedflora,D.White's between Rinehart and Folsom” (Fig. 11). White notes “Callipteris in
fieldnotesrecord“Callipterisreginum[Callipterisconferta]”.Wefound plentyatthetunnelinthe[illegible]dumpandindumpatthew.end