Bedrock geologic map of the Little Switzerland 7.5-minute quadrangle, McDowell and Mitchell counties, North Carolina

Za ByBart L. Cattanach, Sierra J. Isard, and G. Nicholas Bozdog Geology mapped from August 2020 to May 2021. Additional structural measurements from Lewis and Butler (1982).Portions of map modified from Brobst (1962), Bryant and Reed (1970), and Lewis and Butler (1982).Map preparation, digital cartography and editing by G. Nicholas Bozdog, Bart L. Cattanach, and Sierra J. Isard2021 Bedrock Geologic Map of the Little Switzerland 7.5-minute Quadrangle,McDowell and Mitchell Counties, North Carolina This is an Open-File Map. It has been reviewed internally for conformity with North CarolinaGeological Survey mapping standards and with the North American Stratigraphic Code.Further revisions or corrections to this Open File map may occur. Some station data omittedfrom map to improve readability. Please contact the North Carolina Geological Survey forcomplete observation and thin-section data. Research supported by the U.S. Geological Survey, National Cooperative Geologic MappingProgram under STATEMAP (award number G20AC00249, 2020) The views and conclusionscontained in this document are those of the authors and should not be interpreted asnecessarily representing the official policies, either expressed or implied, of the U.S.Government. N.C. North Carolina Department of Environmental QualityDivision of Energy, Mineral and Land Resources Brian Wrenn, DirectorKenneth B. Taylor, State Geologist Little Switzerland 7.5-minute Quadrangle, Open File Report 2021-03 This geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program. North Carolina Geological SurveyOpen File Report 2021-03 ̶●○ ›››› !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ArmstrongCreekArmstrongCreekSlimCreekRattlesnake BranchSouthForkRosesCreekHickoryBottomBranchMartinBranchPupsBranchHarrisCreekCoxCreekCoxCreekODearCreekFirescaldCreekMuddyBranchVanNoyBranchCaneyBranchEastForkBigCrabtreeCreekEastForkGrassyCreekTomsCreekToms CreekThreeMileCreekThreeMileCreekSycamoreBranchDeerstandCreekMaceBranchBartlettCreekLimekilnCreekLimekilnCreekRosesCreekConleyBranchMcGegers BranchSouthForkTomsCreekSheehanCreekBad ForkRagCreekBuchananCreekLongBranchLongBranchPepperCreekPepperCreekLittleBuckCreekLononBranchRoaringForkGrassy 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RidgeWitnessRock RidgeSol RidgeChestnutRidgePups RidgeTennesseeValleyDivideTennesseeValleyDivideBetsy CreekRough RidgeTimber RidgeHensley RidgeWiggins RidgeRich KnobWoodsMountainBrieryMountainStony KnobGrassy KnobBald MountainGraveyardMountainSilver KnobDula KnobLocust KnobGrassyMountainOsborne KnobSnipes TunnelLower BridleTunnelSecond RockyTunnelFirst RockyTunnelThird WashburnTunnelSecond WashburnTunnelUpper PineTunnelLittle Switzerland TunnelUpper BridleTunnelFirst WashburnTunnelBird RidgeTunnelWildacresTunnelQuinn KnobTunnelLower PineTunnelSpeedy TunnelWalnut CoveTurkey Cove 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BESDGSDGFLDSTN_CFLDSDGFLDFLDSTNCUFLDFLDFLDMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICMICTLCMNSTNMNMBLSTNSTNSTNSTN LS11LS1919NB47520BC920BC8620BC9020BC35520NB520NB10520NB13420NB36920SI2620SI3320SI12020SI20620BC26320BC26420NB31020SI2820SI135A20SI135BBC356NB318LZ1 236,000232,000228,000240,000236,000232,000228,000336,000332,000328,000336,000332,000328,000 35°52'30"N82°0'0"W82°7'30"W35°52'30"N35°45'0"N82°7'30"W82°0'0"W35°45'0"N Hillshade derived from a six meter pixel resolution LiDAR (Light Detecting And Ranging) digital elevation model.Red lines show paths of field traverses. TRAVERSE MAP SCHMIDT EQUALAREA STEREONET DATA EXPLANATION OF MAP SYMBOLS CONTACTS Thrust fault (1st option)—Identity and existence certain,location inferred. Saw teeth on upper (tectonically higher plate). Zone of Confidence: 300m Gradational contact—Identity and existence certain,location inferred LINEAR FEATURES Inclined aligned-mineral lineation—Showing bearing and plunge 6 ß Inclined slickenline, groove, or striation on faultsurface—Showing bearing and plunge 18 Ë Inclined fold hinge of generic (type or orientation unspecified)small, minor fold—Showing bearing and plunge 56 < Inclined generic (origin or type not known or not specified) lineationor linear structure—Showing bearing and plunge ½ 12 PLANAR FEATURES (For multiple observations at one locality, symbols are joined at the "tail" ends of the strike lines)(Planar features in red taken from Lewis and Butler, 1982) Small, minor inclined joint—Showing strike and dip Small, minor inclined joint, for multiple observationsat one locality—Showing strike and dip Small, minor vertical or near-vertical joint, for multipleobservations at one locality—Showing strike W Inclined mylonitic foliation—Showing strike and dip Vertical metamorphic or tectonic foliation—Showing strike a Inclined metamorphic or tectonic foliation, for multipleobservations at one locality—Showing strike and dip Inclined metamorphic or tectonic foliation—Showingstrike and dip b 80 c 78 º 23 » 46 Inclined mylonitic foliation, for multiple observationsat one locality—Showing strike and dip S 71 U V 86 66 ` 64 Inclined bedding—Showing strike and dip ¸ 79 OTHER FEATURES x Float station 20SI135B 8##Ó Thin section and whole rock analysis sample location 888888 Thrust fault (1st option)—Identity and existence certain,location accurate. Saw teeth on upper (tectonically higher plate). Contact—Identity questionable, existence certain, locationinferred MIC - Mica SDG - Sand and gravel STN_C - Crushed stone STN - StoneTLC - Talc CU - Copper FLD - Feldspar BE - Beryl MN - Manganese MBL - Marble NATURAL RESOURCES § Prospect (pit or small open cut) © Abandoned sand, gravel, clay, or placer pit « Abandoned open pit, quarry, or glory hole INTRODUCTION GEOLOGIC OVERVIEW REFERENCES DESCRIPTION OF MAP UNITS1 WHOLE ROCK ICP ANALYSIS1 OF SELECTED SAMPLES Whole Rock Inductively Coupled Plasma - Atomic Emission/Mass Spectrometer analysis conducted byBureau Veritas, 9050 Shaughnessy St, Vancouver, BC Canada V6P 6E5.Sample numbers correspond to thin section and whole rock sample localities shown on geologic mapState Plane Coordinate SystemLOI = loss on ignition in percentSUM = Sum total in percentPPM = parts per million. Ni analyzed by Bureau Veritas LF200 and AQ200 procedures. A A' ¼ ¹ d T Small minor vertical or near-vertical joint—Showing strike Vertical metamorphic or tectonic foliation, for multipleobservations at one locality—Showing strike Vertical mylonitic foliation—Showing strike Vertical mylonitic foliation, for multipleobservations at one locality—Showing strike Stereonets created using Stereonet 10 (Allmendinger, et al., 2012; Cardozo and Allmendinger, 2013.) Abandoned adit or tunnel entrance ± _ _ 36 Horizontal foliation Overturned bedding—Showing strike and dip Inclined bedding, for multiple observationsat one locality—Showing strike and dip a 27 c 39 88888 ##################################################################################### mmmmm Contact—Identity and existence certain, locationinferred 270N90180 Contoured poles to joints and unidirectional rosediagram inset. Joint count 923. 270N90180 Bearing and plunge of fold hinges in blue andmineral lineations in red. Fold hinge count 25.Mineral lineation count 12. 270N90180 Contoured poles to mylonitic foliation.Mylonitic foliation count 335. 270N90180 Contoured poles to foliation. Foliation count 683. 19NB475quartz areniteCce97.780.381.550.030.030.020.140.190.010.020.003-0.299.9323<20<1<11.3<0.10.512.42.92.4<12.10.23.5110<0.5491.1811.723.42.38.41.360.221.10.181.380.290.920.141.110.193.57.53.335.41<0.10.1<0.1<0.1<0.5<0.01<0.1<0.520BC90brecciaCce4.971.1580.90.050.060.030.060.121.140.06<0.00211.499.9340841938.22.52.70.80.410.4<116.2<0.10.310.5<82.732.67.52.44.10.843.91.280.341.60.271.590.290.870.151.010.176.447.515.97480.214.20.16.4<0.1<0.110.010.1<0.520NB105metaconglomerateCce86.722.647.230.350.060.020.950.20.150.290.0041.399.93501264419.70.24.82.75.823.4<119.30.34.63.5187.6103.915.52252.35.9623.35.060.964.070.593.240.581.570.231.430.212.3623.44924.85.10.22.80.20.1<0.50.050.7<0.520BC355marbleCs37.39.092.2710.2814.080.743.170.450.10.040.00522.199.76844<20816.61.310.93.59.583.12137.10.77.81.9561.2134.620.228.253.76.323.14.260.553.810.613.630.742.20.332.120.320.53.63.11112.30.7<0.1<0.10.1<0.11<0.01<0.1<0.520SI135AmarbleCs7.010.370.7319.4628.16<0.010.140.020.020.04<0.00243.799.6411<20<1<10.80.2<0.5<0.10.26.9<1260.2<0.10.30.810<0.53.92.74.38.20.953.60.530.190.580.080.50.10.260.040.230.034.1132.9171.910.1<0.1<0.1<0.1<0.5<0.01<0.1<0.520SI135BmarbleCs59.9113.384.232.915.822.393.280.570.170.070.0096.999.811030271145.61.218.89.533.779.63217.32.39.32721.3368.942.444.589.611.4449.011.188.181.317.691.574.450.644.130.660.229.21.43826.9<0.5<0.1<0.1<0.1<0.1<0.5<0.010.1<0.520SI120biotite gneissCZapm66.5816.225.121.690.722.274.370.580.150.070.0072.199.894022517<112.28.921.83.920.7175.9487.91.89.44.4691.71461614.627.83.5413.42.580.512.660.452.820.551.530.231.460.230.339.966121.2<0.5<0.1<0.1<0.1<0.1<0.5<0.010.5<0.520BC263schistose metawackeCZapm74.9611.24.441.2212.212.510.590.150.060.0071.599.89480<20848.24.313.48.114.5932128.60.910.31.7601.4307.617.37.832.52.288.41.780.461.790.342.480.612.030.322.190.350.76.52.95018<0.5<0.1<0.1<0.1<0.1<0.5<0.010.4<0.520BC264schistose metawackeCZapm75.3414.450.870.090.966.11.040.02<0.010.01<0.0021.199.98131<20<120.80.611.50.23.633.4<1127.70.20.90.6<81.64.26.23.64.10.682.70.650.330.770.141.020.210.620.080.440.060.40.911.851.23.8<0.10.1<0.1<0.10.9<0.01<0.1<0.520NB369granitic orthogneissYbm83.987.272.040.310.110.084.470.480.030.01<0.0021.199.95762<204<12.10.57.65.37.772.5<154.50.69.31.3221.5213.319.119.219.34.9519.94.021.073.460.583.490.742.240.342.180.340.11.21.241.6<0.5<0.1<0.1<0.1<0.1<0.5<0.01<0.1<0.520BC86biotite granitic gneissYcu47.2815.3213.923.756.582.053.452.711.430.180.0042.899.6315052120329.31.422.612.632.6114.92786.51.451.71480.6553.845.3115.2226.428.87112.618.85.0614.711.869.581.674.460.63.540.540.921.13.716320.60.5<0.1<0.1<0.1<0.10.6<0.010.6<0.520NB5granitic orthogneissYcu71.6414.142.680.491.073.24.760.260.060.03<0.0021.499.881409<20123.6<0.116.34.96.91091299.40.310.7119<0.5166.59.140.866.56.921.92.850.892.370.31.650.310.860.120.80.120.41.75.5352.2<0.5<0.1<0.1<0.1<0.1<0.5<0.010.2<0.520SI33dioriteYcu58.5217.147.432.034.393.673.360.940.310.11<0.0021.899.81903<208213.60.921.76.110.71443555.70.42.90.992<0.5239.124.737.276.710.0240.17.711.676.520.894.690.882.350.311.980.280.21.61.5825.7<0.5<0.1<0.1<0.1<0.1<0.5<0.010.7<0.5LZ1bggYcu69.8413.444.890.090.84.634.910.390.050.09<0.0020.599.65261<20230.71.138.223.577.469.6433.54.815.12<80.5105889.2306.6498.968.38251.743.272.8333.414.2320.933.69.71.368.751.334.539.12010.8<0.50.3<0.1<0.1<0.1<0.5<0.010.2<0.520BC9biotite gneissYwc81.698.172.640.470.20.063.950.720.020.020.0031.999.92749<205<13.30.59.27.810.765.71350.610.11.5540.6309.51316.146.43.7813.52.40.552.140.362.340.511.630.241.630.270.523.663.64<0.10.1<0.1<0.1<0.50.020.1<0.520SI26gneissYwc67.3214.943.270.792.154.614.330.510.160.05<0.0021.699.871050<20235.50.517.15.614.3125.91248.30.815.21.434<0.5224.618.259112.412.541.35.91.214.480.593.080.61.720.251.590.230.35.32462.90.5<0.1<0.1<0.1<0.1<0.5<0.010.3<0.520SI206myloniteYwc79.19.912.570.640.060.533.310.630.040.02<0.002399.93881<20625.30.510.56.99.173.7127.60.56.61.443<0.5275.15.510.57.71.826.110.230.970.160.980.230.710.130.920.18<0.14.82.71541.6<0.1<0.1<0.1<0.1<0.5<0.01<0.1<0.520SI28areniteYwc69.213.722.61.012.393.392.760.350.10.06<0.0024.299.9679<205<13.22.416.34.89.2108.22204.40.68.72.4250.9174.918.834.768.28.0129.65.261.034.370.613.440.651.930.281.790.270.31.215.6221.53.6<0.1<0.1<0.1<0.1<0.5<0.01<0.1<0.520NB134sandy metawackeZa80.148.533.50.940.6921.720.620.10.040.0041.699.88418<204<16.1<0.19.611.712.942175.80.711.32.1320.5481.324.427.757.26.8325.44.921.194.50.724.320.92.650.382.550.380.83.92.42699<0.1<0.1<0.1<0.1<0.5<0.01<0.1<0.520NB310amphiboliteZaa49.7712.1720.534.886.82.440.271.590.120.350.0040.899.76503147256.70.2182.93.34.9<197.50.10.50.1531<0.593.6465.611.62.28124.051.515.811.077.311.665.230.754.790.780.554.71.94817.4<0.5<0.1<0.1<0.1<0.1<0.5<0.01<0.1<0.5NB318ultramaficZaa63.1813.518.750.0311.360.010.030.550.030.10.0082.399.8213<2012<13.3<0.123.73.314.112968.30.711.31.590<0.5126.227.847.797.310.6739.37.311.346.390.965.521.113.040.432.860.430.2105.5106.2<0.5<0.1<0.1<0.1<0.11<0.01<0.1<0.5LS19metagraywackeZabg69.7713.104.351.352.513.192.640.860.220.070.0041.499.6707310005080270130210160465041096LS11garnet mica schistZabsi60.9118.586.232.570.260.305.441.040.120.030.0094.099.7112250005160120190035050305031016BC356ultramaficZass66.3615.735.031.282.044.092.690.990.190.110.0071.399.84578<201048.91.513.71116.877.72309.51.18.91.5570.5441.429.322.3656.0722.94.441.064.170.744.711.083.690.573.820.660.33.93.76015.81.1<0.1<0.1<0.1<0.1<0.5<0.010.4<0.5SampleRock TypeMap UnitSiO2Al2O3Fe2O3MgOCaONa2OK2OTiO2P2O5MnOCr2O3LOISumBaNiScBeCoCsGaHfNbRbSnSrTaThUVWZrYLaCePrNdSmEuGdTbDyHoErTmYbLuMoCuPbZnNiAsCdSbBiAgAuHgTlSe QUADRANGLELOCATIONLITTLESWITZERLAND,NC2019ROADCLASSIFICATIONCheckwithlocalForestServiceunitforcurrenttravelconditionsandrestrictions.FSPrimaryRouteFSHighClearanceRouteFSPassengerRouteª«-▬InterstateRouteStateRouteUSRouteWX./ExpresswayLocalConnectorRamp4WDSecondaryHwyLocalRoadThismapwasproducedtoconformwiththeNationalGeospatialProgramUSTopoProductStandard,2011.Ametadatafileassociatedwiththisproductisdraftversion0.6.18CONTOURINTERVAL40FEETNORTH AMERICANVERTICALDATUMOF1988SCALE1:2400010005000METERS1000200021KILOMETERS00.5110.50MILES11000010002000300040005000600070008000900010000FEET0°37´11MILS7°8´127MILSUTMGRIDAND2019MAGNETICNORTHDECLINATIONATCENTEROFSHEETNORTHCAROLINANorth AmericanDatumof1983(NAD83)WorldGeodeticSystemof1984(WGS84).ProducedbytheUnitedStatesGeologicalSurveyImagery.....................................................NAIP,May2016-November2016Roads.........................................U.S.CensusBureau,2016RoadswithinUSForestServiceLands........................FSTopoDatawithlimitedForestServiceupdates,2012-2016Names............................................................................GNIS,1980-2018Hydrography...............................NationalHydrographyDataset,2004-2018Contours............................................NationalElevationDataset,2008Boundaries..............Multiplesources;seemetadatafile2017-2018Wetlands.................FWSNationalWetlandsInventory19861Micaville8MarionEast2SprucePine3LinvilleFalls4Celo5 Ashford6OldFort7MarionWestADJOININGQUADRANGLES75146832MNGN(Projection:State Plane North Carolina FIPS 3200 (Meters)4,000-meter ticks:State Plane North Carolina FIPS 3200 (Meters)U.S.NationalGrid100,000-mSquareIDGridZoneDesignationLVMV40017S CORRELATIONOF MAPUNITS NEOPROTEROZOIC Zass Metasandstone CAMBRIAN MESOPROTEROZOIC Brown Mountain granite-biotite phase Ywc Wilson Creek Gneiss Ycu Cranberry Gneiss undivided Erwin Formation Ꞓce Ashe Metamorphic Suite Chilhowee Group Ybmb Brown Mountain granite stratigraphic relationsuncertain undivided amphibolite pegmatite and metasomatic schist ultramafic bodies Zapm Zaa Zau Shady Dolomite Ꞓs The Little Switzerland 7.5-minute quadrangle lies in McDowell and Mitchell counties,western North Carolina. Within the quadrangle is the town of Little Switzerland and thesmaller communities of Woodlawn and Sevier. The Blue Ridge Parkway, U.S. Route 221, andN.C. Highway 226 are the major transportation corridors on the quadrangle. The majorwater feature is the North Fork of the Catawba River and minor water features areArmstrong Creek, Pepper Creek, Cox Creek, and Grassy Creek. Total elevation relief is 2,670feet with a low of 1,260 feet along the North Fork of the Catawba River and a high of 3,930feet at Rich Knob. The Blue Ridge escarpment, the rugged transition zone between the BlueRidge and Piedmont physiographic provinces, transects the quadrangle. The EasternContinental Divide represents the top of the escarpment in this region. Bedrock of the Little Switzerland quadrangle is composed of units within four thrust sheets(from structurally highest to lowest): Fries/Spruce Pine, Fork Ridge, Table Rock, and WilsonCreek. The Table Rock and Wilson Creek thrust sheets comprise the Grandfather Mountainwindow, a tectonic window overlain by the Blue Ridge-Piedmont Megathrust that contains thetwo upper thrust sheets exposed on the quadrangle (Fries/Spruce Pine, and Fork Ridge).Brief descriptions of the units within these thrust sheets are given below, beginning in thenorthwest corner of the map and proceeding to the southeast.FRIES/SPRUCE PINE THRUST SHEETThe Fries/Spruce Pine thrust sheet is part of the western Tugaloo terrane. This thrust sheetcontains Neoproterozoic metasedimentary and mafic rocks of the Ashe Metamorphic Suite.These rocks are thick sequences of complexly deformed and metamorphosed clasticsediments deposited in marine rift basins. Interspersed with these sediments are lesseramounts of mafic volcanic rocks and ultramafic rocks thought to have originated as oceaniccrust at a spreading center (Misra and Conte, 1991; Raymond and Abbott, 1997). Thesemetasedimentary lithologies were complexly deformed and metamorphosed to amphibolitefacies conditions during Taconic orogenesis.Numerous pegmatites occur within the AMS and are thought to be related to the 392-361 Mapegmatites within the Spruce Pine Plutonic Suite (Kish, 1983, 1989; Johnson and others,2001). Pegmatite bodies are typically concordant with metamorphic foliation on thequadrangle. Xenoliths of foliated metasedimentary rocks are locally present within thepegmatites. Metasedimentary lithologies in close proximity to pegmatites are more micaceousand coarse-grained than those where pegmatites are absent.Rocks of the Spruce Pine thrust sheet are structurally above the Fork Ridge thrust sheet.FORK RIDGE THRUST SHEETOn the Little Switzerland quadrangle, the Fork Ridge thrust sheet is comprised of theCranberry Gneiss, a heterogeneous unit consisting of several undifferentiated lithologies. Theunit is interpreted to be Mesoproterozoic in age (Bryant and Reed, 1970) although there maybe Neoproterozoic rocks included within the strongly mylonitic Linville Falls shear zone at thebase of the unit (Trupe, 1997). The primary lithology of the unit is a granitic to granodioriticorthogneiss with lesser amounts of biotite granitic gneiss and amphibolite. Lesser amounts ofchlorite and muscovite within the unit differentiate it from the Brown Mountain Granite on thequadrangle.The Fork Ridge thrust sheet and the underlying Grandfather Mountain Window are separatedby the Linville Falls fault, an Alleghanian greenschist-facies ductile thrust fault (Van Camp andFullagar, 1982).GRANDFATHER MOUNTAIN WINDOWThe Grandfather Mountain Window consists of Mesoproterozoic basement gneisses overlainby rocks of the Table Rock thrust sheet.Tablerock thrust sheetThe Tablerock thrust sheet consists of Cambrian meta-arenites of the Chilhowee Group thatare conformably overlain by the Shady Dolomite. These units represent the rift-to-drifttransition during the opening of the Iapetus Ocean basin (Hatcher et al., 2007). Rocks of theTable Rock thrust sheet are overturned in the southeastern portion of the quadrangle,possibly the result of sheath folding during Alleghanian orogenesis (see Walker, 2012). Theserocks are structurally above the Wilson Creek Gneiss along the Tablerock thrust fault (Bryantand Reed, 1970).Proterozoic basement within the Grandfather Mountain WindowWilson Creek gneiss is primarily a proto- to mylonitic biotite granitic orthogneiss. It outcropsSE of the Linville Falls fault and is interpreted to be Mesoproterozoic in age (Bryant and Reed,1970).The Brown Mountain Granite is locally strongly mylonitic, only recognizable by pinkpotassium-feldspar layers and plentiful chlorite and muscovite. It is structurally above rocks ofthe Table Rock thrust sheet along the Bald Mountain fault. Age of the Brown Mountain Graniteis interpreted to be Neoproterozoic (Bryant and Reed, 1970). Allmendinger, R.W., Cardozo, N., and Fisher, D., 2012, Structural geology algorithms: Vectors and tensors in structural geology; Cambridge University Press.Brobst, D.A., 1962, Geology of the Spruce Pine district, Avery, Mitchell and Yancey counties, North Carolina, U.S. Geological Survey Bulletin 1122-A, map scale 1:24,000.Bryant, B. and Reed, J.C., Jr., 1970, Geology of the Grandfather Mountain window and vicinity, North Carolina and Tennessee: U.S. Geological Survey Professional Paper 615, 190 p.map scale 1:62,500.Cardozo, N., and Allmendinger, R.W., 2013, Spherical Projections with OSXStereonet: Computers & Geosciences, v. 51, p. 193-205, doi:10.1016/j.cageo.2012.07.021.Hatcher, R.D., Jr., Bream, B.R., and Merschat, A.J., 2007, Tectonic map of the southern and central Appalachians: A tale of three orogens and a complete Wilson cycle, in Hatcher, R.D.,Jr., Carlson, M.P., McBride, J.H., and Martínez Catalán, J.R., eds., 4-D Framework of Continental Crust: Geological Society of America Memoir 200, p. 595–632, doi:10.1130/2007.1200(29).Johnson, B.S., Miller, B., and Stewart, K., 2001, The nature and timing of Acadian deformation in the southern Appalachian Blue Ridge constrained by the Spruce Pine Plutonic Suite,western North Carolina: Geological Society of America Abstracts with Program, v. 33, p. A30.Kish, S.A., 1983, A geochronological study of deformation and metamorphism in the Blue Ridge and Piedmont of the Carolinas: Ph.D. Dissertation, University of North Carolina, ChapelHill, 220p.Kish, S.A., 1989, Paleozoic thermal history of the Blue Ridge in southwestern North Carolina - constraints based on mineral cooling ages and the ages of intrusive rocks: GeologicalSociety of America Abstracts with Program, v. 21, p. 45.Lewis, S.E. and Butler, J.R., 1982, Geologic map of the Little Switzerland Quadrangle, North Carolina, unpublished raw dataMisra, K.C. and Conte, J.A., 1991, Amphibolites of the Ashe and Alligator Back Formations, North Carolina: Geological Society of America Bulletin, v. 103, p. 737-750.Raymond, L.A. and Abbott, R.N., 1997, Petrology and tectonic significance of ultramafic rocks near the Grandfather Mountain Window in the Blue Ridge belt, Toe terrane, westernPiedmont, North Carolina, In: Paleozoic Structure, Metamorphism, and Tectonics of the Blue Ridge of Western North Carolina, Carolina Geological Society Field Trip Guidebook, p.67-85.Trupe, C.H. (1997). Deformation and metamorphism in part of the Blue Ridge thrust complex,northwestern North Carolina. [Ph.D. thesis], Chapel Hill, NC: The University of NorthCarolina.Van Camp, S.G. and Fullagar, P.D., 1982, Rb-Sr whole-rock ages of mylonites from the Blue Ridge and Brevard zone of North Carolina, in: Geological Society of America Abstracts withPrograms, v. 14, no. 1-2, p. 92-93.Walker, Ann Elizabeth, 2014, Structural analysis of the Tablerock thrust sheet, Grandfather Mountain window, northwestern North Carolina: Emplacement kinematics of a large horse ina major thrust system. [MS Thesis], University of Tennessee. https://trace.tennessee.edu/utk_gradthes/2760 Shady Dolomite — Light gray to dark gray to bluish gray; fine- to medium-grained; thick-bedded; non- toweakly-foliated; locally mylonitic; locally brecciated; equigranular, granoblastic, consists of primarily of dolomitewith minor quartz, pyrite siderite, feldspar, and muscovite; locally contains chert nodules.Chilhowee GroupErwin Formation— Meta-arenite interlayered with minor amounts of dark-grey, thinly bedded phyllite. Meta-arenite is white to tan, fine- to medium-grained; thin- to thick-bedded; protomylonitic to mylonitic; locallybrecciated with manganese matrix; consists of 80-98% quartz, 1-25% potassium feldspar, 0-10% muscovite/sericite, 1-3% plagioclase, and traces of magnetite, apatite, zircon, epidote group minerals, tourmaline, andsphene.Ashe Metamorphic SuiteMetasandstone — Interlayered metamorphosed sandstones including arkosic arenite, biotite metawacke, andquartzite. Tan to medium-gray to light-green; fine- to medium-grained; foliated to locally mylonitic; equigranularto inequigranular; consists of quartz, feldspar, muscovite, biotite, and minor accessory minerals; notably doesnot contain schist, amphibolite, or garnet.Undivided — Heterogeneous unit consisting of interlayered layers and lenses of laterally and vertically gradingsedimentary and mafic volcanic rocks metamorphosed to kyanite- and sillimanite-grade. Rock types includemetawacke, arkosic meta-arenite, schist, biotite gneiss, amphibolite, and ultramafic rocks. Thickness of layeringranges from centimeters to meters.Metawacke —Medium-light-gray to medium-dark-gray; medium- to coarse-grained; foliated; protomylonitic tomylonitic; equigranular to inequigranular; granoblastic to lepidoblastic; consists of quartz, plagioclase feldspar,biotite, muscovite, garnet, epidote, chlorite, opaque minerals, trace potassium feldspar, kyanite, sillimanite, andzircon; thickness of layering ranges from decimeters to meters. Muscovite-dominated varieties have millimeterscale “pin-striped” fabric.Arkosic meta-arenite — Tan to medium-light-gray to gray; medium-grained, equigranular to inequigranular,foliated; consists of quartz, feldspar, with minor amounts of muscovite, biotite, and other accessory minerals.Schist — Garnet-mica schist, muscovite schist, muscovite-biotite schist; very light-gray to greenish-gray tomedium-gray; medium- to coarse-grained; well-foliated and locally mylonitic; inequigranular; lepidoblastic;consists of plagioclase feldspar, quartz, muscovite, biotite, garnet, kyanite, sillimanite, and minor accessoryminerals.Pegmatite and metasomatic schist — Heterogeneous mix of pegmatite, granodiorite, metasomatic schist,and other Ashe Metamorphic Suite lithologies. Pegmatite bodies range in size from sub-meter to decameterand are typically concordant with surrounding metasediments. Pegmatite is white to light gray to light pink;coarse-grained; granoblastic; consists of plagioclase feldspar, quartz, potassium feldspar, muscovite, biotite,and minor amounts of opaque minerals, and garnet. Metasomatic schist is dark gray; medium- to coarse-grained; well foliated; inequigranular; lepidoblastic; consists of muscovite, biotite, quartz, plagioclase feldspar,potassium feldspar, garnet, and minor accessory minerals.Amphibolite — Dark-green to black; fine- to coarse-grained; weakly to strongly foliated; equigranular;granoblastic to nematoblastic; consists of hornblende, plagioclase feldspar, epidote group minerals, quartz,garnet, chlorite, relict pyroxene, titanite, magnetite, and opaque minerals. Interlayered with other AsheMetamorphic Suite lithologies and locally intruded by pegmatite. Can occur as a minor rock type throughout theother map units, where it may represent a metamorphosed volcanic rock.Ultramafic bodies — Dark-green to silvery-grayish-green; fine- to medium-grained; non-foliated to stronglyfoliated; equigranular; granoblastic to nematoblastic to lepidoblastic; consists of amphibole, relict pyroxene,actinolite, chlorite, talc, serpentine, opaque minerals, plagioclase feldspar, magnetite, spinel, and otheraccessory minerals. These mineralogical variations could not be mapped at a 1:24,000 scale.Brown Mountain granite — Semi-massive variety is coarse grained and equigranular with little chlorite andmuscovite; mylonitic variety is fine- to medium-grained and equigranular with alternating pink potassiumfeldspar layers with silver-green chlorite-muscovite layers; both varieties consist of potassium feldspar, quartz,plagioclase feldspar, muscovite, chlorite, and sericite; may contain small mafic/chloritic pods.Brown Mountain granite-biotite phase — fine- to medium-grained; mylonitic to protomylonitic; locallyporphyroclastic; similar to Brown Mountain granitic orthogneiss but with more biotite.Wilson Creek Gneiss — Heterogeneous unit with dioritic to granitic lithologies that have been variouslysheared. Granitoid - Light-to medium-gray to light pink, fine- to coarse-grained; weakly- to well-foliated;mylonitic to protomylonitic; granoblastic to lepidoblastic; locally strongly layered; locally porphyroclastic; consistsof potassium feldspar, plagioclase feldspar, quartz, biotite and minor amounts of sericite, chlorite, epidotegroup minerals, amphibole, and opaque minerals.Cranberry Gneiss undivided — Heerogeneous unit consisting of granitic orthogneiss with minor amounts ofbiotite gneiss and amphibolite; white to light pink; medium- to coarse-grained; equigranular to inequigranular;mylonitic to protomylonitic; consists of potassium feldspar, quartz, plagioclase feldspar, biotite, and minoramounts of sericite/muscovite, opaque minerals, epidote, chlorite, garnet, and zircon.1Mineral abundances are listed in decreasing order of abundance based upon visual estimates of hand samples and thin-sections. mmmmmmmmmmmmmmmmm#######################################################################################################################################################################################################################################################llllA88888888888888888888888888888888888888888888888888888888 °°ºººººÀÀÀ ÌÌÌÌ YbmYbmbYwcZassꞒsZaaYwcZaaZaaZauZaaZaaꞒceꞒsZaaZaaZaaZaaZaaYcuZaaZapmZaaZaZaZaaZaZaaZaaZaaZaZaZaaZaZaaZaZaaZaZaZaZaZaaZaZaaZapmZapmYbmꞒce Location where garnet was observed Location where chlorite was observed Linville Falls fault Linville Falls fault Tablerock fault Tablerock fault Bald Mountain fault Fork Ridge thrust sheet Spruce Pine thrust sheet Tablerock thrust sheet TECTONIC MAP Ꞓs Ꞓce Zass Za Zapm Zaa Zau Ybm Ybmb Ywc Ycu Tear fault — Identity and existence questionable,location inferred. lllll Ybm (Linear features in red taken from Lewis and Butler, 1982)  À Overturned syncline—Identity and existence certain,location approximate. Beds on one limb are overturned;arrows show dip direction of limbs Inverted syncline—Identity and existence certain,location approximate. Beds on both limbs are overturned;arrows show dip direction of limbs º ° Syncline—Identity and existence certain,location approximate Anticline—Identity and existence certain,location approximate Ì Arrow—Shows plunge direction of fold