NorthCarolinaDepartmentofEnvironmentalQuality NorthCarolinaGeologicalSurveyPolicyandInnovationGroup OpenFileReport2017-15
KennethB.Taylor,StateGeologist
7907'30" 20 3630'00" 50 44 15 70 2 910 85 7900'00" 45 278 28 1012 OMcc2120 7 18 3515 Pflg17 35 13 3011 2880 601618 28 108 724 2588 15 1527 12 208 4617 20 51 3824 4411 52 28 2130 ZMclmOMcc 13 1860 2 38 1625 4024 6021 45 5220 3720 4550 OMcc Pflg 381613 15 7 2313 54 359 656 15 3020 10 10 50 35 3511 3070 10 610 35736 2735 589 30 6 838 707 8 1228 7 121132 13 15 820 12851017 11 8 20 58312 221328 20 1420 4 24 151711 70722214 4 3412 7411 15 8Mkg 15 10 413 2 8 82 28 70 2 2 8 1217 10 207 2212 2 23 ZMclm8 8 3 10 312 39 1275 12 22 65 70 26452 6 10Mkg 1315 30 274465 60 4 2 22 43 5250 87 31 85 24 285212 2 74 2224 63 18 22 2223 7 70 5 3123 6 8510 4 58 15 242 9 26OMcc 65 16 4518 30 18 624 3 20 35ZMclg 202038 5014 85 40 50 20 22 3512 10 45 50 42 345 4 352 85 80 3423 Mygg 60 860 70 3 2573 10 ZMclg23 60 84585 25 60 33 4234 4220 4260 60 17 404 85 3043 9 7512 49 32 35 40 343 5043 65 32 2114 422 42 5213 24 30 13 32 2531 6724 27 62 4232 7022 70 21 2855 10 22 6253 704838 60 5047 7030 4018 3260 42 20 50 30 5053 3630'00" 47 85 7420 69 7420 60 75 ZMclm 401 40 50 60 4012 48850 6055 4560 37 62 55 37 25 57ZMclm 62 48 42 75 28 6720 5350 6765 5833 355 75 39 4860 50 85 325 35 49 432 70 64 8568 507010 78 4070 7680 37 5075 88 43 6 42 40 5840 5054 2872 ZMclm74 67 83 48 4810 25 60 40 CGS53 4057 72 88 55 S.4 35 52Mygg 44 6076 44 20 6762 75 154570 54 3570 25 50 ZMclg1 30573521 3528 5870 8 5025 85 60 54 70 58 42 5672 25 50 5547 55 62 5280 50 857737 85 7075 8080 67 27 45 45 ZMclg29 80 65 6885 50 888 4 234030 65 54 5076 7034 4255 664430 2560 382253 36 52 11 6070 35 260 20 Jd78 5552 ZMclm1 8060 58 70 8055 68 6 6731 74 75 6068 36 7060 63 18 1312 8562 ZMclm 41 62 608580 47 75 60 70 80 Pflg7516 85 85 8554 7575 70 40 4748 85 8575 43 85 85 75 87 808512 60 8572 10 8568 21 68 8013 8530 25 Mkg37 26 85 8525 70 858585 75ZMclm 35 65 67 85 85 Zh8580 8585 8050 85 8069 7585 80 75 70Zog 1027 40 8068 8555 85 6577 6322 852 40 65 8580 7328 50 10 85 85 655512 8588 75 80 80 Zh 70 80 8570 73 70 8517 87 15 60546870 65 2834 78 75 85 80 Mygg2 32 40 6075 70587 2 878565 858 20 3 88834 31 8080 Zog 85 CGSCZrp80S.3B85407562 85 78 OMcc85 70 8085 378285 85 25 8565 70 85 8080 77 20 75 CGS52 8070 6080 60 70S.3A68 33 7080 6088 884080 85 82 67 80 85 538568 80 80 65 13 8880Zog CGS85 1.7 80 ZMclg80 8385 806585 ZMclmCZrp 1 85 80 CZrp CZrp Zog Zh CZrp EXPLANATIO NO FMAPSYMBO LS CO NTACTSANDO THERFEATURES infe red concealed diabaseinfe red lineargeomorphicfeatureapproximatesoutheasternlimit interpretedfromhilshadeofHycoshearzone(gradational) LiDAR-originunknown 24 Strikeanddipofinclinedmainphasefoliation(SM) 72 Strikeanddipoflatepegmatitedike 60 Strikeanddipoflatepegmatitedike58 Strikeanddipofinclinedmainphasefoliation 88 (multipleobservationsatonelocation)16 (multipleobservationsatonelocation) VerticallatepegmatitedikeVerticalmainphasefoliation Verticallatepegmatitedike(multipleobservationsatonelocation)Verticalmainphasefoliation(multipleobservationsatonelocation) 8 Bearingandplungeofminerallineation(LM) 30 Strikeanddipofinclinedmainphasefoliationandlayering(SM+LYR) Horizontalminerallineation(LM) 1555 Strikeanddipofinclinedmainphasefoliationandlayering(SM+LYR) Bearingandplungeofmainphasefoldaxis(FM)85 (multipleobservationsatonelocation) Horizontalmainphasefoldaxis(FM)Verticalmainphasefoliationandlayering(SM+LYR) 25 Bearingandplungeoflatephasefoldaxis(FL)Horizontalmainphasefoliationandlayering(SM+LYR) Horizontallatephasefoldaxis(FL) 12 Strikeanddipofinclinedlatephasefoliation(SL) Observationstationlocation 6 Strikeanddipofinclinedlatephasefoliation(SL) Diabasestationlocation35 (multipleobservationsatonelocation) G roundwatermonitoringwe llocationswithbedrockdataHorizontallatephasefoliation(SL) DukeEnergyRoxboroSteamElectricPlant(SynTe ra,2015) CGS1.71 U-Pbagedateswithassociatednumber2017CarolinaG eologicalSocietyfieldtripstoplocationwithnumber(Hibbardetal.,2017)1�U-Pbagedate-546.5+3.0/-2.4Ma;Roxborogranite(Wortmanetal.,2000)CG S1.7-Roxborogranite2�U-Pbagedate-612.4+5.2/-1.7Ma;Osmondbiotitegranitegneiss(Wortmanetal.,2000)CG SS.3A-Roxborogranite-natureofVirglinadeformation3�U-Pbagedate-619.9+4.5/-3.0Ma;HycoFormationfelsicgneiss(Wortmanetal.,2000) CG SS.3B-Roxborogranite-natureofVirglinadeformationCG SS.4-CountryLineComplexinHycoshearzone IN TRODUCTIO N ThisisacompiledgeologicmapofdatafromgeologicinvestigationsalongtheHycoShearZone.DetaileddiscussionsofthegeologicinterpretationsareprovidedinHibbardetal.(1998)andHibbardetal.(2017).Monitoringwe lboringlocationdatafromtheComprehensiveSiteAssessmentReportfortheDukeEnergyRoxboroSteamElectricPlant(SynTe ra,2015)isincludedonthemap.G eologiccontactsofG loverandSinha(1973)weremodifiedbasedonnewlycolectedgeologicdata. UnitDescriptions Jd�Diabase:Blacktogreenish-black,fine-tomedium-grained,diabase;consistsprimarilyofplagioclase,augiteandmaycontainolivine.Occursasdikesupto100ftwide.Typicalyoccursas spheroidalyweatheredboulderswithagrayish-brownweatheringrind. Aleghaniangranitoids(ca.335-319Ma) Pflg-FarmersLakegranite:Lightgrey,weaklytomoderatelyfoliated,homogeneousfine-tomedium-grainedbiotitegranite.Thegraniteoccursassporadicstocksanddikes,mostofwhich aretoosmaltoberesolvedat1:24,000scalemapping.ItintrudestheKilgoregranite,theCunninghamcomplex,andtheCountryLinecomplex.AU-Pbzirconagedateof319.6+/-0.7Maonthegranite(YanceyvileQuadrangle.)isinterpretedtoreflectthecrystalizationageofthepluton(Wortmanetal.1998). Mkg-Kilgoreorthogneiss:Mediumgrey,medium�tocoarse-grained,K-feldspar-plagioclase-quartz-biotiteorthogneiss.Localymegacrysticandheterogeneouslydeformed;feldspar commonlydisplaysadistinct�clastic�texture.Deformationrangesfromasingle,weaktomoderatefoliationtothenorthwesttoanintense,gneissicfoliationinthesoutheast,alongthecontactbetweentheplutonandadjacentCountryLinecomplex.Inmostplacesalongthecontact,theKilgoregranitegneissisconcordantlyinterlayeredwithgneissoftheCountryLinecomplex,althoughlocaly,itcrosscutslayeringinthecomplex(She l,1996).TheKilgoregneissalsocontainsenclavesofamphiboliteanddioritelithicalyidenticaltoimmediatelyadjacentCountryLine complexrocksinthehangingwal.Theseenclavesrangefromequidimensionalpodsinthenorthtoelongatenarowlensesandlayersinthesouth.Themaficenclavescontainagneissiclayeringandfoliationthatisgeneralyobliquetothefoliationinthesuroundinggranitoid.A327�1.5MaU-PbzirconagefromtheKilgoregranite(ontheLeasburgQuadrangle.)isinterpretedasthecrystalizationageforthepluton(Wortmanetal.,1998). Mygg-YanceyvilleO rthogneiss(includedintheCountryLinecomplex):Whitishtolightgrey,foliated,medium�tocoarse-grainedbiotitegranitegneiss.Overprintedbythesamesequence ofdeformationasthesuroundingmaficgneissesintheCountryLinecomplex.Containsxenolithsoftheenclosinglayeredmaficgneissesandlocaly,dikesofthegranitegneisscrosscutlayeringinthemaficgneisses(She l,1996).TheYanceyvilegranitegneisshasaU-Pbzirconageof335.4+/-2.2Ma(Wortmanetal.1998)(ontheYanceyvileQuadrangle). MiltonTe rane�Milton-ChopawamsicArc(ca.475-450Ma) O Mcc-Cunninghamcomplex:Heterogeneousmixtureofmediumtodarkgreybiotitegneissandbiotiteschistrangingfrommassive,equigranulargranticgneisstolayersandlensesofbiotite�garnet�silimaniteschist.Themostcommonrocktypeisbiotitegneissthatrepresentsahybridbetweenthesetwoend-members,althoughdistinctiregular-shapedareasofeitherend-membercanbefound.ThegraniticgneissislocalyK-feldsparmegacrysticwithcrystalsupto50mmlong.Layering,atcentimetertometerscale,isdefinedbyfeldsparporphyroclast concentrationaswe lasbiotitecontent;itisgeneralysubtleinmostoftheunit,butitisaccentuatednearthecontactofthegneisseswiththeCountryLinecomplex.Localy,meter-scalepodsof amphibolite,dioriticgneiss,andcalc-slicategneissareenvelopedinamatrixofbiotitegneiss.ThegranticgneissiscompositionalysimilartoandappearstogradeintotheCarboniferousKilgoreorthogneiss.Thebiotiteschistissimilarto,andappearstogradeintotheO rdovician(?)Miltonschistandparagneiss.ThusthecomplexappearstobeamixtureofOrdovicianandMississippianrocks. CarolinaTe rane TheCountryLinecomplex(ca.614�323Ma) ZMclg�Unseparatedbiotitegraniteorthogneiss:Buffweathering,mediumgrey,weaklytostronglyfoliated,mainlymediumgrainedbiotitegranite. ZMclm�NeoproterozoicmaficgneissandamphiboliteinterlayeredwithMississippianpegmatitesandorthogneiss:G reenschisttoamphibolitefaciesmaficgneisseswithinterlayered granitoidsandgranticpegmatites;subordinatebiotitegneissandminormetapyroxenite,semipeliticschist,andfelsicschist(She l,1996).Themaficgneissesrangefromamphibolitestobiotite-amphibolegneisses.Commonly,theyarelayeredonacentimetertometerscale,althoughinsomeplacestheyaremassive,withamedium�tocoarse-grainedgabbro-liketexture.Themafic gneissesareextensivelyinterlayeredwithgraniticpegmatites,localyenvelopebrownish-grey,fine-grainedgranitoids,andareintrudedbycross-cuttinggraniticpegmatites. N orthoftheYanceyvilegranitegneiss(YanceyvileandLeasburgquadrangles),thecomplexischaracterizedbyaveryregularlylayered(centimeter-scale),fine-tomedium-grainedgraybiotite+blackishgreenamphibolegneisswithinterlayeredgraniticgneiss(She l,1996).Localy,overthespanofafewmeters,theregularlylayeredgneissgradesintomigmatite(sensulato)witha networkoffoliatedcoarsegranitoidcontainingmeterscalepodsofamphibolitewithlayeringandfoliationobliquetothatinthegranitoid. BiotitegneissisaminorcomponentoftheCountryLinecomplex;typicalyitisafine-tomedium-grainedequigranular,grayquartz-feldspar-biotite+garnetgneiss.G eneralyitformsmassive andhomogeneouslens-shapedbodiesthataretoosmaltoberesolvedat1:24,000. Zirconfromalayeredmaficgneisssub-unitintheSouthBoston,VAareahasyieldedadiscordantupperinterceptageof613.9+/-9.3Mathatisinterpretedtoreflectaprotolithageforthemafic gneisses.Zirconandsphenefromthesamesamplehaveyieldedaconcordantageofca.323Ma(Wortmanetal.,1998).ConcordantlyinterlayeredpegmatitesincreaseinvolumetowardstheMississippianYanceyvileorthogneiss(YanceyvileandLeasburgquadrangles),suggestingthattheconcordantpegmatitesarealsoMississippian.Thus,thecomplexisamixtureofN eoproterozoicandMississippianrocks. AlbemarleArc(ca.550-530Ma) CZrp-RoxboroPluton:Massivetolocalyveryweaklyfoliated,leucocratic(CIlessthan10),pinkish,medium�tocoarse-grained,hypidiomorphicgranular,metamorphosedgranite.Mafic mineralspresentinrockaremostcommonlybiotiteintergrownwithchloriteand/orhornblendeintergrownwithactinolite.PlutonmappatterntruncatesAaronFormationunitsandHycoFormation volcanics.Wortmanetal.(2000)reportedaU-Pbageof546.5+3.0/-2.4MafortheRoxboropluton.BoulderfieldsareacommongeomorphicexpressionabovetheRoxboropluton. HycoArc(ca.635-610Ma) Zog-O smondGranite:Lightgrey,fine-tomedium-grained,foliatedbiotitegranite.Wortmanetal.(2000)reportedaU-Pbageupperinterceptdateof612.4+5.2/-1.7Ma. Zh-HycoFormation:Dominantlygreenschistfaciesfelsicvolcanicandvolcaniclasticrockswithsubordinateintermediateandmaficcomponents.Theformationextendsalongtheeastern marginoftheHycoshearzone.Primaryfeaturesarewe lpreservedinmostoftheHycoFormation.Themostcommonrocktypeisfelsiccrystaltuffcontainingabundantanhedralcrystalsof eitherquartzorplagioclaseupto3mmindiameter.Thetuffsaretypicalyinterlayeredwithfelsiclapilituffs,quartz-muscovitephylites,pebblyvolcanicconglomerate,andintermediatetomafic crystaltuffs.TheHycoFormationrecordsfelsictointermediatemagmatismduringaca.20m.y.spanstartingatca.633Ma(Wortmanetal.,2000;BradleyandMiler,201). REFEREN CES: Almendinger,R.W .,Cardozo,N.C.,andFisher,D.,2013,StructuralG eologyAlgorithms:VectorsandTensors:Cambridge,England,CambridgeUniversityPress,289pp.Cardozo,N.,andAllmendinger,R.W .,2013,SphericalprojectionswithOSXStereonet:ComputersandG eosciences,v.51,no.0,p.193-205,doi:10.1016/j.cageo.2012.07.021Bradley,P.J.andMiller,B.V.,2011,N ewgeologicmappingandageconstraintsintheHycoArcoftheCarolinate raneinOrangeCounty,N orthCarolina:G eologicalSocietyofAmericaAbstractswithPrograms,Vol.43,N o.2.Glover,L.,I,andSinha,A.,1973,TheVirglinadeformation,alatePrecambriantoEarlyCambrian(?)orogeniceventinthecentralPiedmontofVirginiaandN orthCarolina:AmericanJournal ofScience,v.273-A,p.234-251.Hibbard,J,Bradley,P.andShel,G.,2017,RampingthroughthePiedmont�AnoverviewofthegeologyoftheHycoShearZone,north�centralN orthCarolina,inHibbard,J.,Bradley,P.andOwens,B.,RampingthroughthePiedmont�theHycoShearZoneandassociatedrocksinN orth�centralN orthCarolina,CarolinaG eologicalSocietyFieldTripG uidebook2017.Hibbard,J.,Shel,G.,Bradley,P.,Samson,S.,andW ortman,G.,1998,TheHycoshearzoneinN orthCarolinaandsouthernVirginia:ImplicationsforthePiedmontZone-CarolinaZoneboundaryinthesouthernAppalachians:AmericanJournalofScience,v.298,p.85-107.Shel,G.S.,1996,N atureoftheCarolinaslatebelt-MiltonbeltboundarynearYanceyvile,N orthCarolina:M.S.thesis,N orthCarolinaStateUniversity,Raleigh,N orthCarolina,96p.SynTera,2015,ComprehensiveSiteAssessmentReport�DukeEnergyRoxboroSteamElectricPlant,pages904.AccessedfromN CDepartmentofEnvironmentalQuality,DivisionofWaterResourcesonlinedocumentlibraryin2017.W ortman,G.,Samson,S.,andHibbard,J.,1998,PreciseU-PbtimingconstraintsonthekinematicdevelopmentoftheHycoshearzone,southernAppalachians:AmericanJournalScience,v.298,p.108-130.W ortman,G.,Samson,S.,andHibbard,J.,2000,PreciseU-PbzirconconstraintsontheearliestmagmatichistoryoftheCarolinate rane:JournalofG eology,v.108,p.321-338.
Equal-AreaSchmidtNetProjections andRoseDiagram PlotsandcalculationscreatedusingStereonetv.8.6.0basedonAlmendingeretal.(2013)andCardozoandAlmendinger(2013).
Zh
CZrp
3622'30" 7907'30" Zh 3622'30" 7900'00" Hibbard(1998) G loverandSinha(1973) EqualAreaSchmidtN etProjectionofContouredPolestoMainPhaseFoliationandLayering(SM)[blackcircles]andBearingandPlungeofMainPhaseLineations(LM)[redtriangles]ContourInterval=2sigmaMainPhaseFoliationN=525MainPhaseLineationN =79 ContoursdisplayedforSMonly EqualAreaSchmidtN etProjectionofContouredPolestoLatePhaseFoliation(SL)ContourInterval=2sigmaN=95
IN DEXTO G EO LO G ICMAPPIN G
EqualAreaSchmidtN etProjectionofBearingandPlungeofmainphasefoldaxes(FM)[redcircles]andlatephasefoldsaxes(FL)[black circles] UnidirectionalRoseDiagramofLatePegmatitesN=31OuterCircle=30%Meanvector=025.0��06.6� Maxvalue=29.03226%between021�and030�
CompiledGeologicMapoftheHycoShearZonePortionsoftheAltonandOliveHil7.5-MinuteQuadrangles,OpenFileReport2017-15
CompiledGeologicMapoftheHycoShearZoneandAdjacentPortionsofthe
ThisisanOpenFileMap.Ithasbeenreviewedinternalyforconformitywith
AltonandOliveHil7.5-MinuteQuadrangles,PersonCounty,NorthCarolina
N orthCarolinaGeologicalSurveymappingstandardsandwiththeN orthAmericanStratigraphicCode.FurtherrevisionsorcorectionstothisOpenFile mapmayoccur.
Geologyby:JamesP.Hibbard(includesmodfiedcontactsofLynnGlover,IIIandA.K.Sinha)
ACKN OWLEDGEMEN TS
DigitalCartographyby:BrandonT.Peach,MichaelA.Medina,andPhlipJ.Bradley ThisresearchwassupportedbytheNationalScienceFoundation:GrantsEAR�9219979andEAR9506363toJ.HibbardandEAR-9219583toS.Samson.
2017
