Geologic map of the Oxford 7.5-minute quadrangle, Granville and Vance Counties, North Carolina

DEPARTMENTOFENVIRONMENTANDNATURALRESOURCES NORTHCAROLINAGEOLOGICALSURVEYDIVISIONOFLANDRESOURCES OPENFILEREPORT2006-01 GEOLOGICMAPOFTHEOXFORD7.5-MINUTEQUADRANGLE,GRANVILLEANDVANCECOUNTIES,NORTHCAROLINA BYDAVIDB.PARNELL,DAVIDE.BLAKE,RICHARDM.WOOTEN,CINDYM.PHILLIPS,ANDPAULF.FARRIS DigitalrepresentationbyMichaelA.Medina,NormanK.Gay,CindyM.Phillips,andTimothyW.Clark 2006 EXPLANATION SEDIMENTARYUNITS 7837'30 3622'30 ThisgeologicmapwasfundedinpartbytheUSGSNationalCooperativeGeologicMappingProgram 64 3587 71 36 8185 78 CZsvp 68 80 80 42 47 64 78 65 85 84 75 40 5076 56 6852 80 75 45 70 66 65 44 CZcbg 87 75 80 70 87 55 CZgbdi CZcpm Jd 78 75 75 56CZgr 88 61 65 59 CZg 71 5654 83 CZsmv 5670 55 49 70 80 CZgrf CZgrf CZgrf 70 54 75 CZcbgf 78 43 7080 74 80 84 64 89 64 60 70 CZafg 65 78 62 75 78 68 84 7446 52 82 57 68 CZg CZgrf 70 57 60 88 85 75 4670 74 CZcbgf 45 70 70 75 85 75 8474 4056 52 67 77 CZgrf 60 CZafg82 66 CZcbgf 75 55 72 6572 79 87 CZbgp 85 55 71 81 82 B 54 64 CZgr 60 6380 80 85 65 77 45 B' 63 Jd 71 74 60 Qal67 CZdi 57 85 CZafg CZgr 64 CZgr 85 81 85 76 60 66 4545 60 57 78 79 78 68 85 80 68 6076 71 75 80 60 CZgrf 74 77 65 CZgrfCZmdp CZg 72 Qal 66 55 75 87 qv 45 1565 85 81 87 6087 5085 60 45 CZgbdi 89 74 83 CZdi CZgr 74 10 80 54 70 60 75 85 8080 86 CZgrf 48 Jd6868 80 75 64 80 6577 70 89 65 75 85 87 CZgr 65 65 CZgbdi 45 55 88 76 Qal 85 80 88 58 64 85 75 75 75 82 CZgr Qal 8572 Qal 62 76 8385 85 44 85 CZdi Qal Qal 70 5885 74 75 88 68 78 60 80 CZphs CZabf 65 85 85 75 75 89 CZphc 75 60 70 70 80 CZgr75 qv 70 CZgbdi CZgrf 85 55 Qal CZbgp Qal 60 40 85 72 70 CZgr 74 Jd DUJd 55 Qal 78 60 85Jd 42 70 80 CZdq 70 85 8040 20 80 75 85 85 Trcc/s 70 75 85 80 CZphs 78 JdTrcbr35 4565 75 CZgbdi Qal 70 70 60Trcc DU 62 5080 CZgrf 65 73 30 60 50 60 52 78 D U 6065 D50U 55 qv qv 62 80 CZpyg CZdqf Qal 40 50 74 35 65 65 80 64 60 65 55 DU 76 49 65 87 78 15 25 80 45 85 CZdq70 80 85 80 77 62 70 65 Qal CZgbdif 75 qv 80 85 80 55 60 69 67 85 CZphc 40 32 70 75 68 78 CZdqf62 70 58 65 60 CZdqf CZab 70 78 45 72 84 85 CZgr CZdq 50 80 65 58 CZpyba 68 70 CZphs 60 87 70 70 65 80 80 60 80 45 45 70 80 CZg 48 58 67 71 60 60 62 78 572 52 CZphs 70 85 CZdq 85 80 CZdq CZgbdi 17 85 48 55 85 50 85 CZtjf 60 72 53 6585 65 75 72 CZmd 50 70 CZphs CZphcs CZdq 50 72 40 45 60 65 84 25 24 CZphc ? CZgr 70CZtg 70 45 Qal 60 30 Jd66 85 80 45 58 qv 80 CZdq 52 D66 U 60 60 Qal CZgr60 CZgbdi 75 85CZdq 60 60 60 85 83 CZmdp 80 80 70 65 CZdq 85 Jd 8075 858368 CZdq 60 70 7076 42 82 qv 25 85 CZab CZgr 70 83 75 82 88 79 39 55 88 80 88 55 64 66 40 40 55 CZab CZab 85 73 75 57 80 86 CZdq CZdq 85 80 69 69 40 80 68 79 80 CZdqf 69 68 68 81 89 64 Trcc Qal 85 79 Qal 80 7058 A 52 84 69 A' 65 qv 7760 85 45 65 85A" 65 65 80 8042 37 45 CZgbdi 65 80 7011 85 60 85 61 72 75 CZg 85 80 73 CZtjf 6070 65 72 50 CZgr 71 6565 CZdi CZab 5273 85 35 40 qv 65 45 75 80 8075 60 60 55 73 80 50 85 s 78 40 55 80 80 85 40 85 76 75 80 50 1872 65 79 65 Trcc/ 50 45 65 CZphcs Qal 85 79 80 80 CZdq 85 71 65 DU 45 60 70 Jd 50 55 78 27 CZdq 74 77 60 70 82 Qal 80 78 8574 70 47 78 80 60 31 60 85 59 60 87 60 65 75 CZgbdi 70 45 qv 70 CZtcf 56 65 33 CZmd 70 10 72 75 42 6562 55 74 82 CZdq 45UD 82 22 80 60 60 45 4275 83 CZgr CZtg Trcc 45 40 75 50 CZgrf CZdi 81 80 31 CZgrf 78 CZdi 55 80 60 74 CZdqf CZphs 6065 76 72 80 72 80 80 80 50 55 CZgrf 6176 Qal 72 55 CZgr 80 66 62 60 85 82 79 90 86 75 85 80 70 85 CZga 65 86 85 69 CZtcJdCZdqf CZphcs CZgb 77 CZdi 82 81 90 75 62 80 85 75 74 7681 82 7060 CZtcf CZgr CZphcs 70 85 7085 CZga 27 CZdqf 85 65 90 90 76 CZtc 68 50 86 85 Trcc 30 49 55 47 75 CZtc CZtc 65 75 82 CZpyba 55 5 60 50 qv Jd CZdiCZgr Trcc/s CZgd CZdi CZgr 72 76 65 CZfp LatePaleozoic LateProterozoictoCambrian toMesozoic(?) Jurassic LateTriassic Quaternary Qal-Quaternaryalluvium:Tan,toyellow-brownandlightbrownunconsolidated,Qal clay,siltandsandmixtures.Primarilysandysiltandsiltysandbutincludeslocal gravellyhorizonswithinfloodplainsofmajorcreeksandtributaries. Trcc-conglomerateandmuddysandstone:Reddish-brown,clast-supported,cobble Trcc andboulderconglomeratewithsubordinatesandy,gravellyconglomerateandmuddysandstone.Predominantlithicfragmentsofsubangulartosubroundedgranitic andotherfelsicintrusiverocks;matrixcontainsbothmudandsandcomponents. Trcc/s-conglomerate,sandstone,andmudstone:Reddishbrown,clast-tomatrix-Trcc/s supported,poorlysorted,gravelconglomerate,conglomeraticmuddysandstone,muddysandstone,andsubordinatemudstone. Trcbr-sandstoneandmudstonebreccia:Mottledred,yellowish-brown,andlightgray Trcbr brecciaandfoliatedbrecciaderivedfromTriassicsedimentaryrocks.Hematite coatingsonsubparallelslipsurfacesinmudstoneandsiltstoneimpartafoliated appearance;brecciaconsistsprimarilyofangularsandstonefragmentsinamuddymatrix. IGNEOUSROCKS Jd-diabase:Steeplydippingtosub-verticaldikesofdarkgraytoblack,fine-to medium-graineddiabasethatmaybeolivinebearing.Crosscutsothermeta-intrusiveunits.Solidlineswhereobserved,dashedwhereinferred,anddotted whereconcealed.Redcirclesindicateareasofabundantfloatinferredtobenear originallocation. qv-veinquartzandquartzbreccia:Whitetolightgray,coarse-grained,highly qv fracturedveinquartzandbrecciatedveinquartz.Typicallyassociatedwith shearzones;locallycontainssericiteand/orchloritephylloniteclasts.Down-dipslickenlinescommononfractureplanes. METAMORPHICROCKS CZpyg-metagranite:Pinkpotassiumfeldsparphenocrysts(2-8mm)andgrayCZpyg quartzphenocrystsinaporphyritic,medium-grained,grayandwhitegroundmass.Occurasdikescross-cuttingothermeta-intrusiveunits. CZg-granite:Graytomediumpinkorpinkish-orange,medium-tocoarse-grained, CZg biotitegraniteandquartzmonzonite,+/-accessoryhornblende;mainlyequigranularbutlocallyporphyritic.Pinkpotassiumfeldspardistinctive;rosequartzcommon.GenerallyunfoliatedexceptforalocallydevelopedfracturecleavagewithsericitefilmsinthevicinityoftheFishingCreekfault. CZgr-felsicmeta-intrusivesuite:Leucogranite,trondhjemite,granite,and CZgr granodiorite.Generallyleucocraticrangingfrompalepinktolightgray,medium-to coarse-grained,typicallywithquartzphenocrystsinafelsicmatrix.Sericitepartlyreplacesperthiticmicrocline,andsericiteandepidotegroupmineralspartlyreplace plagioclase.Biotiterangesfrom<10%toaccessoryamountsinleucocraticunits;accessorymagnetitelocallypresent.Includesenclavesofgrayish-greentogreenish-blackmetabasaltandmeta-andesite(CZab).Generallyunfoliatedbutincludeslocalizedfoliatedvarieties,andsericite,quartzphyllite,andphyllonite. CZdq-meta-quartzdiorite:Lightgray,whiteandblack,fine-tomedium-grained, CZdq mesocratic,+/-accessoryhornblende,biotite,meta-quartzdioriteandsubordinate meta-granodiorite.Plagioclasepartiallyreplacedbysericiteandepidotegroupminerals;chloritereplacesbiotiteandhornblende.Quartzcomposes5-25%ofthe rock,locallyaslight,blue-grayphenocrysts.Includesenclavesanddikesofgrayish-greentogreen-blackmeta-basaltandmeta-andesite(CZab). CZdi-metadiorite:Gray,whiteandblack,medium-tocoarsegrained,mesocratic CZdi quartz,hornblendediorite.Chloritereplaceshornblendeandcombinedcomposes upto40%oftherock.Locallycontainsblue-grayquartzinamountslessthan5%.Invadesandincludesenclavesanddikesofgray-greentogreen-blackmeta-basalt andmeta-andesite(CZab). CZgbdi-meta-hornblendegabbro-diorite:Darkgraytogreen-black,medium-to CZgbdi coarse-grained,hornblendeplagioclasemetagabbroandmetadiorite.Minorto accessoryamountsofquartzarepresentinthemetadiorite.Accessorymagnetiteassociatedwithchloritizedhornblendeiscommon,andsecondarypink potassiumfeldsparislocallypresent.Epidotegroupmineralscommonlyreplace plagioclaseandimpartapalegreencolorinhandsample;chloritetypicallyreplaceshornblende.Relictclinopyroxene(augite?)israrelypresentenclosed withinhornblende.Generallyunfoliatedtoweaklyfoliated;however,well-developedfoliationsdefinedbychloritearecommoninlocalizedshearzonesandcontacts withotherrockunits.Typicallyincludesenclavesofgrayish-greentogreenish-black metabasaltandmeta-andesite(CZab). CZgb-metagabbro:Blacktograyish-blackmelanocratic,fine-tomedium-grained CZgb metagabbro.Relictpyroxeneandmetamorphichornblendecommon;magnetite presentinsufficientamountstomaketherockdistinctlymagnetic.Sheared varietiesalongthecontactwiththeFishingCreekfaultzoneincludemyloniteandblastomylonitewithpinkfeldsparporphyroclasts;and,chloriteplagioclasephyllitetypicallywithcompositeS-Cfabric. CZtc-TabbsCreekmeta-igneoussuite:Variablygreencolored,fine-tomedium- CZtc grained,variablyfractured,greenstonetometagabbroandmetadiorite.Crosscutbyfine-tocoarse-grainedbiotitehornblendemeta-quartzdioritetometagranodiorite,andlocallymetatrondhjemitetometagranite.Greenstonetometagabbroand metadioriteformsenclaveswithinmorefelsicrocks,orexhibitvariablyorienteddikesofmorefelsicrocks. CZtcf-foliatedTabbsCreekmeta-igneoussuite:Foliatedequivalentofvariably CZtcf greencolored,fine-tomedium-grained,variablyfractured,greenstonetometagabbro andmetadioriteandcrosscutingfine-tocoarse-grainedbiotitehornblendemeta-quartzdioritetometagranodiorite,andlocallymetatrondhjemitetometagranite.Locallychlorite andwhitemicadefinefractureandshearfoliations. CZpyba-meta-andesite.Fine-graineddikeswith2-6mmplagioclasephenocrysts commonlyalteredtoepidote)inaporphyritic,fine-graineddarkgreengroundmass ofquartz,chlorite,epidoteandhornblende.Chloritealsooccursreplacinghornblende.Occurasthin(<10mwide)dikes. CZab-meta-andesiteandmetabasalt:Fine-graineddarkgray-greentoblack-green, CZab melanocratic+/-quartz,chlorite,epidote,hornblendeplagioclaserocks.Chlorite replaceshornblendeandepidotegroupmineralsreplaceplagioclase.Accessorymagnetiteandquartzarecommon.Generallyunfoliated,foliatedvarietiesdefinedbyalignedchloritehornblendeoccur."Boxworks"fabricdefinedbyintersectingquartz-epidoteveinsisdistinctive.Probablyrepresentshypabyssalbasaltand andesiteintrusives,aswellasveryfine-grainedequivalentsofmeta-dioriteand meta-gabbrounits.Occurscommonlyasenclaveswithinotherintrusiverockunits.EquivalentinparttothegreenstoneunitofCook(1968),andmaficvolcanicunit ofHadley(1974). CZga-alteredgranite:Pinkandgreen,topinkandgraymetagraniteand CZga meta-quartzmonzonite.Sericitepartiallyreplacespotassiumfeldspar;sericiteand epidotepartiallyreplacesplagioclasefeldspar;highlyfracturedandbrecciated varietieswithironandmanganeseoxidefracturecoatingsoccurinthevicinityoftheFishingCreekfault.Thinchloriteandsericitefilmscoatingfractureplanesdefine afracturecleavage.PinkpotassiumfeldsparandgreenchloriteisdistinctiveinfoliatedvarietiesalongwithcompositeS-Cfabric.AlteredequivalentofCZg. CZgrf-foliatedfelsicmeta-intrusivesuite(CZgr):IncludespalegreentolightCZgrf gray+/-chlorite,sericitequartzphylliteandphyllonite.CompositeS-Cfabric,andfracturecleavagecommon.Foliatedequivalentoffelsicmeta-intrusivesuite(CZgr). CZtjf-metatrondhjemite:Whitetopalegray,fine-grained,foliatedepidote,sericite, CZtjf quartz,plagioclaserock.Differentiatedquartzo-feldspathicandsericitelaminae characterizelocallydevelopedmyloniticvarieties.Accessorypalegreenepidote and+/-5%pyritearedistinctive. CZdqf-foliatedmeta-quartzdiorite:Biotite,commonlyreplacedbychlorite,defines CZdqf foliationsurfacesalongwithsericiteandflattenedquartzandfeldsparphenocrysts;S-Ccompositefabriccommon,aswellaslocalizedveryfine-grainedsiliceousmylonite.Includeszonesof+/-chlorite,sericite,quartzphylliteandphyllonite.Foliatedequivalent ofmeta-quartzdiorite(CZdq). Jd Jd Jd Jd CZgrf-foliatedfelsicmeta-intrusivesuite(CZgr):IncludespalegreentolightCZgrf gray+/-chlorite,sericitequartzphylliteandphyllonite.CompositeS-Cfabric,andfracturecleavagecommon.Foliatedequivalentoffelsicmeta-intrusivesuite(CZgr). CZdi-metadiorite:Gray,whiteandblack,medium-tocoarsegrained,mesocratic CZdi quartz,hornblendediorite.Chloritereplaceshornblendeandcombinedcomposes upto40%oftherock.Locallycontainsblue-grayquartzinamountslessthan5%.Invadesandincludesenclavesanddikesofgray-greentogreen-blackmeta-basalt andmeta-andesite(CZab). CZgbdi BlakeandParnell,2005-2006 Wooten,Blake,Phillips,andFarris2002 INDEXTOGEOLOGICMAPPING 0.5 2,000 500 0 0 0 0.5 1 1.5 Miles 2,000 4,000 6,000 Feet 500 1000 1500 Meters Disclaimer:ThisOpen-FilereportispreliminaryandhasnotbeenreviewedforconformitywiththeNorthCarolinaGeologicalSurveyeditorial standardsorwiththeNorthAmericanStratigraphicCode.Further revisionsorcorrectionstothispreliminarymapmayoccurpriortoitsreleaseasaNorthCarolinaGeologicalSurveymap. StereonetProjections*andRoseDiagramsofStructuralElementsforWooten,Blake,Phillips,andFarris-2002fieldseason *lowerhemisphereequalarea(Schmidt)projectionsC.I.=0.5% ScanwithsmartphoneforlinktoGeoPDFofmap.ThirdpartyApprequired. STRUCTURALSYMBOLS Observationsitesarecenteredonthestrikebarorareattheintersectionpointofmultiplesymbols. 75 foliation foliation-vertical 78 shearorregional shearorregional shearfoliation shearfoliation-vertical 62 joint joint-vertical 67 axialplane bedding 81 fracturesurface fracturesurface-vertical 72 igneouscontact igneouscontact-vertical 76 fracturecleavage fracturecleavage-vertical 82 34enclavefoliation brittlefault 84 ductilefault ductilefault-vertical 1121 slickenlinelineation mineralstretchlineation 17 19foldaxis intersectionlineation quartzbrecciastationlocation 7830' 3622'30 ofrockunitsforWooten,Blake,Phillips,andFarris-2002fieldseason EXPLANATION ofrockunitsforBlakeandParnell�2005-2006fieldseason SEDIMENTARYUNITS Qal-Quaternaryalluvium:Tan,toyellow-brownandlightbrownunconsolidated,Qal clay,siltandsandmixtures.Primarilysandysiltandsiltysandbutincludeslocal gravellyhorizonswithinfloodplainsofmajorcreeksandtributaries.INTRUSIVEROCKS Jd-diabase:Steeplydippingtosub-verticaldikesofdarkgraytoblack,fine-to medium-graineddiabasethatmaybeolivinebearing.Crosscutsothermeta-intrusiveunits. qv-veinquartzandquartzbreccia:Whitetolightgray,coarse-grained,highlyqv fracturedveinquartzandbrecciatedveinquartz.Typicallyassociatedwith shearzones;locallycontainssericiteand/orchloritephylloniteclasts.Down-dipslickenlinescommononfractureplanes. CarolinaTerraneMETAMORPHICROCKS CZgr CZgr-felsicmeta-intrusivesuite:Leucogranite,trondhjemite,granite,and granodiorite.Generallyleucocraticrangingfrompalepinktolightgray,medium-to coarse-grained,typicallywithquartzphenocrystsinafelsicmatrix.Sericitepartlyreplacesperthiticmicrocline,andsericiteandepidotegroupmineralspartlyreplace plagioclase.Biotiterangesfrom<10%toaccessoryamountsinleucocraticunits;accessorymagnetitelocallypresent.Includesenclavesofgrayish-greentogreenish-blackmetabasaltandmeta-andesite(CZab).Generallyunfoliatedbutincludeslocalizedfoliatedvarieties,andsericite,quartzphyllite,andphyllonite. CZgbdi-meta-hornblendegabbro-diorite:Darkgraytogreen-black,medium-to coarse-grained,hornblendeplagioclasemetagabbroandmetadiorite.Minorto accessoryamountsofquartzarepresentinthemetadiorite.Accessorymagnetiteassociatedwithchloritizedhornblendeiscommon,andsecondarypink potassiumfeldsparislocallypresent.Epidotegroupmineralscommonlyreplace plagioclaseandimpartapalegreencolorinhandsample;chloritetypicallyreplaceshornblende.Relictclinopyroxene(augite?)israrelypresentenclosed withinhornblende.Generallyunfoliatedtoweaklyfoliated;however,well-developedfoliationsdefinedbychloritearecommoninlocalizedshearzonesandcontacts withotherrockunits.Typicallyincludesenclavesofgrayish-greentogreenish-black metabasaltandmeta-andesite(CZab). CZgs CZgs-greenstone:Greentogreen-grey,finetomediumgrained,massivetypicallyspheroidalbouldersconsistingofplagioclase,pyroxene,hornblende,epidotegroupminerals,andtypicallypyritebearing.Generallyunfoliatedandvariablyfractured,commonlyoccurringasenclaveswithinCZmd.Presentoncrosssectiononly. CZmd CZmd-mediumgrainedmetadiorite:Darkgreytogreenblack,mediumtolocallyfinegrainedhornblendeplagioclasemetadiorite.Epidotemineralscommonlyreplace plagioclaseimpartingapalegreencolorinhandsample.Outcropsaslargeabundantbouldersincreekbeds. CZmdp CZmdp-fine�tomedium-grainedmetadioriteporphyry:Darkgreytoblackphorphyritic metadiorite.Finegraineddarkgreygroundmassconsistingofplagioclase,pyroxene,andhornblendeholdtabularplagioclasecrystals1-6mminsize.Locally,phenocrysts ofpotassiumfeldsparoccur.Thisunitisintrusiveintosurroundingunits. CZtg CZtg-unfoliatedmeta-biotitetonaliteandminormetagranodiorite:Variablygreen-greytogrey-white,mediumtocoarsegrainedbiotitetonalite,andmetagranodiorite.Quartzisabluishtolocallylightgrey,withplagioclasecommonlyshowingalterationtoepidote groupminerals. CZg CZg-granite:Graytomediumpinkorpinkish-orange,medium-tocoarse-grained,biotitegraniteandquartzmonzonite,+/-accessoryhornblende;mainlyequigranularbutlocallyporphyritic.Pinkpotassiumfeldspardistinctive;rosequartzcommon.GenerallyunfoliatedexceptforalocallydevelopedfracturecleavagewithsericitefilmsinthevicinityoftheFishingCreekfault. CZbgp CZbgp-coarse-grainedmeta-biotitegraniteporphyry:Tantobrownmesocratictoleucocratic,mediumtocoarsegrainedbiotitegraniteporphyry.Bluishtogreyquartz phenocrysts,1-3mminsizearesetinamatrixofplagioclaseandpinkpotassiumfeldspar.Biotiteoccursassmallmaficclots. CZcbg CZcbg-chlorite/biotitemetagranite:Green-blacktopinkmesocraticmediumtocoarse grainedbiotite-chloritemetagranite.Chloritereplacesbiotiteandtogethermakesupapproximately30-40%oftherock.Plagioclaseshowsminorreplacementbyepidote groupminerals,locallyphorphyritic,quartzandpotassiumfeldsparmakeupthefinergrainedportionsoftherock. CZcbgf CZcbgf-foliatedChlorite/Biotitemetagranite:Foliatedequivalentofgreen-black mesocraticmediumtocoarsegrainedbiotite-chloritemetagranite.Chloriteandwhite micalocallydefinefractureandshearfoliationsaswellasflattenedplagioclasecrystals. CZafg CZafg-alkalifeldspargranite:Pinkishtoorangemediumtocoarsegrainedalkalifeldspargranite.Quartzphenocrysts1-2mminsize,appearbluishinhandsample,andpinkishorangepotassiumfeldsparphenocrysts,1-2mminsizeoccurina groundmassofnearlyallpotassiumfeldsparwithminorquarts.Rockunitoccurs assmallundeformedintrusivebodiesthroughoutthestudyarea. CZphc CZphc-chloriteschist,phylliteandphyllonite:Lightgreenish-graytodarkgreen,phyllitic rocksderivedprimarilyfromshearedintermediateandmaficintrusiverocks(CZdq,CZdi,andCZgbdi);includeschlorite,sericitephylliteandphyllonite;and,sericite,quartzo�feldspathicmylonite.Myloniticfabriclocallydevelopedasmillimeter-scaledifferentiated micaceousandquartzo�feldspathiclaminaealongwithflattenedandrotatedpolycrystalline quartz-plagioclaseaggregates.Includesthinzonesoffoliatedmeta-quartzdiorite(Czdq)andmetagabbro(CZgbdi).S-Ccompositefabriccommon,andhighlyfracturedandbrecciatedvarietiesoccurneartheFishingCreekfault. 3615' 3615' CZcpm CZcpm-chloritephylloniteandmylonite:Lightgreenish-graytodarkgreen,foliatedandlineatedphylliticrocksderivedprimarilyfromrecrystallizedfelsic,intermediate,andmaficintrusiverocks.Includeschloriteandsericitephylloniteandmylonitethatformindistinctive relictcompositionallayers.Ironandmanganeseoxidecommonlycoatsfracturedandfoliated surfaces.Flattenedandrotatedpolycrystallineaggregatesofplagioclaseandquartzcommon asporphyroclasticminerals.Quartz,feldspar,chlorite,andwhitemicacontributetoa slickenlinelineation. 7837'30 7830' CZsmv CZsmv-silicifiedmetavolcanicrock:Darkgreytoblackmelanocraticveryfinegrained silicifiedmetavolcanicrock.Generallycontainsaccessorysulfideminerals,most commonlypyrite.Outcropsaslargetomediumsizedbouldersthatarevariablyfractured.LocallyitisintrudedbyCZbgpandCZmdp. CZsvp CZsvp-silicifiedvolcanicporphyry:Whitetotan,veryleucocraticSilicifiedporphyry.Containsphenocrystsofgreyquartzandisvariablyfractured.Thisunitoutcropsastwodistinctiveresistantsiliceouscentersoccurringontopographichighs.Locallyit containsenclavesofCZsmv. ShearZoneRocks CONTACTS Lithologiccontacts-Solidwherelocationknown,dashedwhereinferred,dottedwhereconcealed. FAULTS Faults-Solidwherelocationknown,dashedwhereinferred,dottedwhereconcealed. GeologymappedMay,2002throughOctober,2002(SEOxford)andJanuary,2006throughMay,2006.SupportedbytheU.S.GeologicalSurvey,NationalCooperativeGeologicMappingProgram,underassistanceAwardNo.01HQAG0061(SEOxford)and05HQAG0082.Theviewsandconclusionscontainedinthisdocumentarethoseoftheauthorsandshouldnotbeinterpretedas necessarilyrepresentingtheofficialpolicies,eitherexpressedorimplied,oftheU.S.Government. LOCATIONOFTHEOXFORD7.5-MINUTEQUADRANGLE,NORTHCAROLINA crosssections: noverticalexaggerameasurementinfee t re ferencemeanseal iton CZpyba Czgbdif-foliatedmeta-hornblendegabbroanddiorite:Chloritedefinesfoliation CZgbdif surfacesalongwithflattenedandalignedhornblendeandplagioclasephenocrysts.Includeszonesofchloriteplagioclasephylliteandphyllonite.Foliatedequivalent ofmeta-quartzdiorite(CZgbdi). Czabf-foliatedmeta-andesiteandmetabasalt:ChloritedefinesfoliationsurfacesCZabf andincludeslocalizedzonesof+/-sericite,chloritephyllite.Foliatedequivalentof meta-andesiteandmetabasalt(CZab). CZphc-chloriteschist,phylliteandphyllonite:Lightgreenish-graytodarkgreen,phyllitic CZphc rocksderivedprimarilyfromshearedintermediateandmaficintrusiverocks(CZdq,CZdi,andCZgbdi);includeschlorite,sericitephylliteandphyllonite;and,sericite,quartzo�feldspathicmylonite.Myloniticfabriclocallydevelopedasmillimeter-scaledifferentiated micaceousandquartzo-feldspathiclaminaealongwithflattenedandrotatedpolycrystalline quartz-plagioclaseaggregates.Includesthinzonesoffoliatedmeta-quartzdiorite(Czdq)andmetagabbro(CZgbdi).S-Ccompositefabriccommon,andhighlyfracturedandbrecciatedvarietiesoccurneartheFishingCreekfault. CZphs-sericite,quartzschist,phylliteandphyllonite:Lightgrayphylliticrocksprobably CZphs derivedfromshearedfelsicintrusiverocks,andpossiblyfelsicpyroclasticrocks.Myloniticfabriclocallydevelopedasmillimeter-scaledifferentiatedmicaceousandquartzofeldspathicl ihfl enedandro edpol abri , l eve approximatescale1:24,000 CZphcs aminaealongwS-Ccompositef t att ccommon. tat ycrystallinequartz-plagioclaseaggregates. CZphcs-sericite,chloriteschist,phyllite,andphyllonite:Lightgrayish-greenphylliticrocks probablyderivedfromshearedintermediateintrusiverocks.Myloniticfabriclocally am developedasmillimeter-scaledifferentiatedmicaceousandquartzofeldspathicl withflattenedandrot tz-plagioclaseaggregates.S-Ccomposfabr iccommon. atedpolycrystallinequar inaealit e ong I-77 I-85 I-95 I-40 I-26 I-85 I-77 I-95 I-40 ductileshearzone 1:24,000SCALECONTOURINTERVAL10FEET Basetopographicmapisdigitalrastergraphicimage oftheOxford7.5-minuteUSGSquadrangle(1981),LambertConformalConicmetersprojectionNorthCarolinaStatePlaneNAD83coordinatesystem HachersRun US15 I-85 FishingCreek A' NC96 A 500' 0' -500' CZgs CZgs -1000' -1500' CZg CZmd CZtg CZgbdi -2000' -2500' CZmd Jd CZgs -3000' -3500' B JordanCreek US15 CoonCreek B' 500' 0' -500' -1000' -1500' -2000' -2500' -3000' -3500' CZsmv CZbgp CZmdp CZg CZgrf CZgr CZgr CZgrf CZgr 500' 0' -500' -1000' -1500' -2000' -2500' -3000' -3500' FISHINGCREEKFAULTZONE Coon FishingCreek Tabbs Poplar A" Trcc/s Trcc Creek Fault CZab Creek Creek 500' CZg Qal CZab CZgbdi CZdq Qal CZab CZdq 0' -500' CZphc Jd -1000' ? ? CZdq CZdq ? CZphs CZgr CZphcs CZgr CZphcs CZdi CZdqf CZgr CZdqf -1500' -2000' -2500' -3000' -3500'