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

North Carolina Department of Environmental Quality Energy Group Jenny Kelvington, Executive Director Kenneth B. Taylor, State Geologist Equal-Area Schmidt Net Projections and Rose Diagram Plots and calculations created using Stereonet v. 8.6.0 based on Allmendinger et al. (201 3) and Cardozo and Allmendinger (201 3). Equal-Area Schmidt Net Projection of Contoured Poles to Metamorphic and Shear Foliations Contour Interval = 2 sigma N = 383 Equal-Area Schmidt Net Projection of Contoured Mineral Lineations and Mineral Stretching Lineations Contour Interval = 2 sigma N = 26 Equal-Area Schmidt Net Projection of Slickenlines, Down-Dip Mineral lineations and Poles to Brittle Fault Planes Squares: Slickenlines n = 21 Circles: Down-dip Mineral Lineations n = 13 Triangles: Poles to Brittle Fault Planes n = 18 Unidirectional Rose Diagram of Joints N = 331 Outer Circle = 6% Mean vector = 342 degrees Unidirectional Rose Diagram of Spaced Cleavage N = 94 Outer Circle = 12% Mean vector = 205 degrees Unidirectional Rose Diagram of Fracture Surfaces N = 330 Outer Circle = 6% Mean vector = 53 degrees This Geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program CZdito f V\ CZdito гтс?р^м ШтШ ffeiiin ■ A 80 80 jvCZgbdi i|.w. . U * CZdi ,I''\ s' >85 CZgbdi у illtOWJl iSm Shitjijf Grovt) Base topographic map is digital raster graphic image of the Oxford 7.5 minute USGS quadrangle (1981). UTM GRID AND 1981 MAGNETIC NORTH DECLINATION AT CENTER OF SHEET 0.5 SCALE 1:24 000 0 1 1,000 500 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 I — I I — I I - 1 I I Feet ) Miles 0.5 0 H H H I 1 I Kilometers CONTOUR INTERVAL 10 FEET Satterwhite Stovall Townsville Berea Oxford Henderson Stem Wilton Kittrell ADJOINING 7.5’ QUADRANGLES Map ID Sample ID Rock type Map Unit Si02 ТЮ2 AI203 Fe203 MnO MgO CaO Na20 K20 P205 Cr203 LOI TOTAL Ag As All Rb Sr Cu Mo Та Zn Zr UNITS wt% wt% wt% wt% wt% wt% wt% wt% wt% wt% vvt% % % ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm Del. Limits 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 1 1 0.2 0.1 5 2 0.5 1 OX-1 hornblende metadiorite CZgbdi 51.05 1.94 18.73 8.93 0.17 3.03 7.13 4.72 0.89 0.63 <0.01 2.05 99.39 <1 3 20.1 630 19 <2 1.1 1 OX-I (DUP) hornblende metadiorite CZgbdi 50.9 1.94 18.73 8.94 0.17 3.03 7.15 4.74 0.89 0.63 <0.01 2.05 99.28 <1 8 20 628 19 <2 l.l 2 OX-11 metagranite CZg 76.39 0.2 12.97 1.56 <0.01 0.15 0.22 4.1 4.08 0.02 0.02 0.75 100.6 <1 2 88.8 92.7 8 3 1.6 3 OX-303 biotite metagranite CZvgr 72.26 0.29 14.36 2.45 0.05 0.64 1.93 4.4 3.27 0.08 0.02 0.65 100.5 <1 <1 87.8 225 9 <2 0.5 4 OX-313 metatrondjhemite CZdqf 71.19 0.31 14.98 2.79 0.01 0.77 1.89 5.08 1.57 0.08 <0.01 1.6 100.4 <1 5 43.6 301 68 4 <0.5 5 OX-324 biotite quartz metadiorite CZdq 69.29 0.39 15.47 3.32 0.07 1.21 2.38 4.65 2.08 0.11 0.01 1.3 100.4 <1 <1 51.5 281 59 3 <0.5 6 OX-328 qiz hornblende metadiorite CZdq 57.89 1.18 15.7 9.1 0.19 2.54 5.81 4.12 1.47 0.27 <0.01 1.5 99.88 <1 <1 40.4 429 15 <2 <0.5 7 OX-352 hornblende metagabbro CZgbdi 47.71 2.49 16.88 12.2 0.27 4.04 8.3 4.34 0.42 0.95 <0.01 1.75 99.47 <1 6 5.6 674 41 <2 1.1 8 OX-376 porphyritic meta-andesite CZpyba 53.42 1.62 15.33 12.47 0.2 3.06 7.33 2.41 0.46 0.34 <0.01 2.85 99.58 <1 5 12.7 459 1 17 <2 0.7 9 OX-379 chorite-sericite phyllite CZphc 56.33 1.3 15.94 10.47 0.12 2.91 4.87 4.03 0.8 0.38 <0.01 2.55 99.82 <1 6 22.4 402 73 <2 <0.5 10 OX05-6068A greenstone CZmd 53.00 1.12 15.4 11.2 0.18 4.7 8.62 3.18 0.88 0.19 0.01 1.55 100.1 <1 <1 <1 22.7 111 <2 <0.5 109 3.3 10 0X05-6068 В quartz metadiorite CZmd 61.5 0.7 16.4 5.42 0.1 2.22 5.29 4.44 1.64 0.18 <0.01 l.l 99.1 <1 <1 <1 35.4 26 <2 <0.5 63 1.2 11 0X05-6085 quartz metadiorite CZmd 56.5 1.13 17.4 7.79 0.14 2.98 6.39 4.39 0.98 0.24 <0.01 1.5 99.5 <1 <1 <1 19.1 63 <2 <0.5 57 1.7 12 0X05-6183 metadiorite CZmd 55.3 0.8 17.6 7.52 0.11 4.11 7.79 4.04 0.8 0.21 <0.01 1.15 99.5 <1 <1 <1 16.1 37 <2 <0.5 43 2.1 13 0X05-6 196A greenstone CZtg 55.5 1.38 15.5 10.7 0.13 3.24 5.17 3.58 2.13 0.31 <0.01 1.75 99.6 <1 <1 <1 57.4 98 <2 <0.5 119 5.2 13 OX05-6I96B metagranodiorite CZtg 69.7 0.35 15 2.75 0.06 1.13 3.04 4.48 2.32 0.1 <0.01 1.05 100.1 <1 <1 <1 48.3 7 <2 <0.5 33 7.7 14 0X05-6340 greenstone CZg 49.4 1.63 16.3 10.3 0.26 5.44 8.06 3.15 2.67 0.35 0.01 1.35 98.9 <1 <1 <1 84.4 96 <2 <0.5 133 7.1 Select data provided in Geochemical analyses Sample series OX-1 to Total Fe as Fe203 table. Additional data available in spreadsheet format upon request. completed by SGS Minerals, Toronto, Canada for 1 1 major and trace elements. Whole-rock analyses used various methods as noted below. OX-379 analyzed by XRF103 and MS95. Sample series 0X05 analyzed using method codes XRF76Z + 75V, IMS95A, and FAI303, and individual element method code ICMS12B for Та. LOI = percent weight loss on ignition Blank data cell indicates sample not analyzed for paramater North Carolina Geological Survey Open File Report 2016-19 The pre-Mesozoic crystalline rocks of Oxford 7.5-minute Quadrangle are part of the Neoproterozoic Carolina terrane. These rocks are metamorphosed to the chlorite zone of the lower greenschist facies during Neoproterozoic and Paleozoic tectonothermal activity. Only Late Triassic sedimentary rocks and Jurassic diabase are not regionally metamorphosed, although contact metamorphic effects occur locally where diabase intrudes sedimentary rocks. While subjected to this low-grade regional metamorphism and locally displaying fracture, foliation, and lineation, most crystalline rocks preserve relict plutonic, volcanic, or volcanogenic sedimentary textures, which when combined with bulk rock compositions, allow for protolith identification. In some exposures, especially adjacent to the trace of the Fishing Creek Fault, highly partitioned strain produces either highly fractured, phyllonitic, or protomylonitic and mylonitic rocks of meta-igneous origin. Local outcrops of highly silicified, epidotized, and/or sericitized, or silicified-epidotized cataclasite rock have unclear protolith affinity. All sedimentary rocks of Mesozoic and Cenozoic age have a detrital origin involving clay- to gravel-sized sediment. The northern portion of the quadrangle was the subject of a masters thesis by Parnell (2012). Parnell (2012) information, unit descriptions and unit contacts were used to update the Parnell, et al. (2006) map. The classification and naming of metaigneous rocks in the Oxford 7.5-minute Quadrangle uses the nomenclature of the International Union of Geological Sciences (IUGS) subcommission on the systematics of igneous rocks after Le Maitre (2002). Relict igneous textures, modal mineral assemblages, or normalized mineral assemblages when whole-rock geochemical data are available, provide the basis for naming metaigneous lithodemes. A preliminary lithodemic designation is developed here following Articles 31-42 of the North American Stratigraphic Code. These rock units, which lack in geochronologic data and stratigraphic facing directions, warrant such a designation. Sedimentary Units “ Qal - Quaternary Alluvium: Tan, to yellow-brown and light brown unconsolidated, clay, silt and sand mixtures. Primarily sandy silt and silty sand but includes local gravelly horizons within flood ua plains of major creeks and tributaries о Tree - Conglomerate and muddy sandstone of the Chatham Group Lithofacies Association III: Red brown, clast-supported, cobble and boulder conglomerate with subordinate sandy, gravelly conglomerate and muddy sandstone. Predominant lithic fragments are subangular to subrounded granitic and felsic intrusive rocks; matrix contains both mud and sand components. Trcc/s - Conglomerate, sandstone, and mudstone of the Chatham Group Lithofacies Association III: Red brown, clast- to matrix-supported poorly sorted, gravel conglomerate, conglomeratic muddy sandstone, muddy sandstone, and subordinate mudstone. Trcbr - Sandstone and mudstone breccia: Mottled red, yellow-brown, and light gray breccia and foliated breccia derived from Triassic sedimentary rocks. Hematite coatings on subparallel slip surfaces in mudstone and siltstone impart a foliated appearance; breccia consists primarily of angular sandstone fragments in a muddy matrix. Intrusive Unit Jd - diabase: Steeply dipping to sub-vertical dikes of dark gray to black, fine- to medium-grained diabase that may be olivine bearing. Crosscuts other meta-intrusive units. Solid lines where observed, dashed where inferred, and dotted where concealed. Red circles indicate areas of abundant float inferred to be near original location. CAROLINA TERRANE qv qv - vein quartz and quartz breccia: White to light gray, coarse-grained, highly fractured vein quartz and brecciated vein quartz. Typically associated with shear zones; locally contains sericite and/or chlorite phyllonite clasts. Down-dip slickenlines common on fracture planes. Locally contains/includes subhedral quartz crystals as vein infilling. Metaintrusive and Metavolcanic Rocks CZpyba CZpyba - Porphyritic meta-andesite: Fine-grained dikes with 2-6 mm plagioclase phenocrysts (commonly altered to epidote) in a fine-grained dark green groundmass of quartz, chlorite, epidote and hornblende. Chlorite also occurs replacing hornblende. Occur as thin (less than 10 m wide) dikes. CZdito CZdito - Metadiorite-meta-tonalite: Mesocratic to melanocratic (Cl = 50-65) dark gray to green-black, phaneritic, diorite, quartz metadiorite, and hornblende-biotite metatonalite. Outcrops as medium to large boulder fields on hillsides and farm fields, but also in creek bottoms. Minor to accessory amounts of quartz are present in the diorite, while in the tonalite portions, quartz are typically gray up to 4 mm in length. Accessory magnetite associated with chloritized hornblende is common, and accessory potassium feldspar is locally present. Epidote group minerals commonly replace plagioclase and impart a pale green color in hand sample; chlorite typically replaces hornblende. Rare relict clinopyroxene present enclosed within hornblende. Generally unfoliated to weakly foliated; however, well developed foliations defined by chlorite are common in localized shear zones and contacts with other rock units. Typically includes enclaves of grayish-green to green-black metabasalt and meta-andesite. Outcrop-scale crosscutting relationships indicate felsic lithodemes CZpbg, CZgr, and CZg are younger than unit. CZgs - Greenstone: Green to green-grey, fine to medium grained, massive typically spheroidal boulders consisting of plagioclase, pyroxene, hornblende, epidote group minerals, and typically pyrite bearing. Generally unfoliated, commonly occurring as enclaves within CZmd. Present on cross section only. CZmd CZmd - Medium grained metadiorite: Dark grey to green black, medium to locally fine grained hornblende plagioclase metadiorite. Epidote minerals commonly replace plagioclase imparting a pale green color in hand sample. Outcrops as large abundant boulders in creek beds. CZdi CZdi - Metadiorite: Gray, white and black, medium- to coarse grained, mesocratic quartz, hornblende diorite. Chlorite replaces hornblende and combined comprises up to 40%. Locally contains blue-gray quartz in amounts less than 5%. Invades and includes enclaves and dikes of gray-green to green-black metabasalt and meta-andesite (CZab). CZdq CZdq - Quartz metadiorite: Light gray, white and black, fine- to medium-grained, mesocratic, +/- accessory hornblende, biotite, quartz metadiorite, subordinate metagranite (with subordinate meta-granodiorite). Plagioclase partially replaced by sericite and epidote group minerals; chlorite replaces biotite and hornblende. Quartz comprises 5-25% of the rock, locally as light, blue-gray phenocrysts. Includes enclaves and dikes of gray-green to green-black metabasalt and meta-andesite (CZab). CZdqf 1 L CZdqf - Foliated equivalent of quartz metadiorite: Biotite, commonly replaced by chlorite, defines foliation surfaces along with sericite and flattened quartz and feldspar phenocrysts; S-C composite fabric common, as well as localized, very fine-grained siliceous mylonite. Includes zones of +/- chlorite, sericite, quartz phyllite and phyllonite. CZdp CZdp - Metadiorite Porphyry: Mesocratic to Melanocratic (01=40-60) dark gray to black, porphyritic metadiorite: Contains plagioclase, hornblende, minor biotite, and opaque minerals. Plagioclase phenocrysts reaching 1 cm in length are contained in an aphanitic matrix, and have undergone extensive sausserite (epidote) and sericite reaction replacement commonly with the phenocrysts core more extensively altered than the rims indicating normal zoning. Locally, phenocrysts of K-feldspar occur. This unit is intrusive into surrounding units. CZgbdi CZgbdi - Hornblende metagabbro-metadiorite: Dark gray to green-black, medium- to coarse-grained, hornblende plagioclase metagabbro and metadiorite. Minor to accessory amounts of quartz are present in the metadiorite. Accessory magnetite associated with chloritized hornblende is common, and secondary pink potassium feldspar is locally present. Epidote group minerals commonly replace plagioclase and impart a pale green color in hand sample; chlorite typically replaces hornblende. Relict clinopyroxene (augite?) is rarely present enclosed within hornblende. Generally unfoliated to weakly foliated; however, well-developed chlorite foliations are common in localized shear zones and contacts with other rock units. Typically includes enclaves of gray- green to green-black meta-basalt metabasalt and meta-andesite (CZab). CZgbdif CZgbdif - Foliated equivalent of hornblende metadiorite-metagabbro: zones of chlorite plagioclase phyllite and phyllonite. Chlorite defines foliation surfaces along with flattened and aligned hornblende and plagioclase phenocrysts. Includes CZgb - Metagabbro: Black to gray-black melanocratic, fine- to medium-grained metagabbro. Relict pyroxene and metamorphic hornblende common; magnetite present in sufficient amounts to make the rock distinctly magnetic. Sheared varieties along the contact with the Fishing Creek fault zone include mylonite and blastomylonite with pink feldspar porphyroclasts; and, chlorite plagioclase phyllonite typically with composite S-C fabric. CZvgr CZvgr - Felsic meta-intrusive suite (Vance County pluton): Leucogranite, trondhjemite, granite, and granodiorite. Generally leucocratic ranging from pale pink to light gray, medium- to coarse-grained, typically with quartz phenocrysts in a felsic matrix. Sericite partly replaces perthitic microcline and sericite and epidote group minerals partly replace plagioclase. Biotite ranges from less than 10% to accessory amounts in leucocratic units; accessory magnetite locally present. Includes enclaves of gray-green to green-black metabasalt and meta-andesite (CZab). Generally unfoliated but includes localized foliated varieties, and sericite, quartz phyllite and phyllonite. fczvgf ' 1 L CZpyg CZvgf - Foliated equivalent of felsic meta-intrusive suite (Vance County pluton): Includes pale green to light gray +/- chlorite, sericite quartz phyllite and phyllonite. Composite S-C fabric, and spaced cleavage common. Includes enclaves of greenstone consisting of gray-green to green-black metabasalt and meta-andesite (CZab). CZpyg - Porphyritic metagranite: Pink potassium feldspar phenocrysts (2-8mm) and gray quartz phenocrysts in a medium-grained gray and white groundmass. Occur as dikes cross- cutting other meta-intrusive units. CZafg CZafg - Alkali feldspar granite: Pinkish to orange medium to coarse grained alkali feldspar granite. Quartz phenocrysts 1-2 mm in size, appear bluish in hand sample, and pinkish orange potassium feldspar phenocrysts, 1-2 mm in size occur in a groundmass of nearly all potassium feldspar with minor quarts. Rock unit occurs as small undeformed intrusive bodies through out the study area. ezigd \ CZfgd - Foliated biotite granodiorite: Mesocratic (Cl=35) green-black to pink, medium to coarsely crystalline, foliated biotite granodiorite. It crops out as small circular to ovoid shaped pods in the creek bottom of Coon Creek, some outcrops show only a weak incipient foliation; however along Coon Creek within the Fishing Creek Fault Zone, it becomes a protomylonite. Contains quartz, plagioclase, k-feldspar, chlorite, and minor opaque mineral clots. Chlorite and white mica locally define fracture and shear foliations as well as flattened plagioclase crystals. Chlorite encases rotated and asymmetrical plagioclase and quartz porphyroclasts that display wings of recrystallized quartz and plagioclase in protomylonitic rock types, while schistose rocks consist of mostly chlorite and display a composite S-C fabric foliation development. ' — 1 — Г pzgcf , CZgcf - Foliated Gibbs Creek pluton: Foliated and locally lineated equivalent of the metagranodiorite. Chlorite and white mica define a metamorphic overprint upon biotite, hornblende and feldspar, and are well developed in phyllonitic to mylonitic fracture and shear foliation zones. Less foliated rocks develop a sheen due to fine-grained, oriented white mica overprint of feldspar. Millimeter- to centimeter-scale relict feldspar phenocrysts define a porphyroclastic microstructure. Locally zones of silica and epidote that form silicified ridges overprint the foliated rocks, especially in its western portions. Description from adjacent Wilton quadrangle. Polygon added to edge-match with adjacent quadrangle. czte CZtc - Tabbs Creek Meta-Igneous Suite: Variably green colored, fine- to medium-grained, variably fractured, greenstone to metagabbro and metadiorite. Crosscut by fine- to coarse-grained biotite hornblende quartz metadiorite to metagranodiorite, and locally metatrondhjemite to metagranite. Greenstone to metagabbro and metadiorite forms enclaves within more felsic rocks, or exhibit variably oriented dikes of more felsic rocks. cztef 1 L CZtcf- Foliated equivalent of Tabbs Creek Meta-Igneous Suite: Foliated equivalent of variably green colored, fine- to medium-grained, variably fractured, greenstone to metagabbro and metadiorite and crosscuting fine- to coarse-grained biotite hornblende quartz metadiorite to metagranodiorite, and locally metatrondhjemite to metagranite. Locally chlorite and white mica define spaced cleavage and shear foliations. cztjf CZgd CZtjf - Metatrondhjemite: White to pale gray, fine-grained, foliated epidote, sericite, quartz, plagioclase rock. Differentiated quartzo-feldspathic and sericite laminae characterize locally developed mylonitic varieties. Accessory pale green epidote and +5% pyrite are distinctive. CZgd - Metagranodiorite: Grayish-white, coarse-grained, unfoliated and locally fractured, leucocratic (Cl less than 15), blue-gray quartz biotite +/- hornblende (?) metagranodiorite. Description from adjacent Wilton quadrangle. Polygon added to edge-match with adjacent quadrangle. CZtg CZtg - Unfoliated biotite metatonalite and minor metagranodiorite: Variably green-grey to grey-white, medium to coarse grained biotite metatonalite, and metagranodiorite. Quartz is a bluish to locally light grey, with plagioclase commonly showing alteration to epidote group minerals. CZg CZg - Metagranite: Gray- medium pink or pink-orange, medium- to coarse-grained, biotite metagranite and quartz metamonzonite, +/- accessory hornblende; mainly equigranular but locally porphyritic. Pink potassium feldspar distinctive; rose quartz common. Generally unfoliated, but a locally developed spaced cleavage with sericite films occurs in the vicinity of the Fishing Creek fault. CZga CZbgp CZga - Altered equivalent of CZg: Pink and green, to pink and gray metagranite and quartz metamonzonite. Sericite partially replaces potassium feldspar; sericite and epidote partially; replaces plagioclase; highly fractured and brecciated varieties with iron and manganese oxide fracture coatings occur in the vicinity the Fishing Creek fault. Thin chlorite and sericite films coating fracture planes define a fracture cleavage; Pink potassium feldspar and green chlorite is distinctive in foliated varieties along with composite S-C fabric. Greenstone occurs locally as enclaves consisting of green to green-grey, fine to medium grained, massive typically spheroidal boulders consisting of plagioclase, pyroxene, hornblende, epidote group minerals, and typically pyrite bearing. CZbgp - Coarse-grained biotite metagranite porphyry: Tan to brown mesocratic to leucocratic, medium to coarse grained biotite metagranite porphyry. Bluish to grey quartz phenocrysts, 1- 3mm in size are set in a matrix of plagioclase and pink potassium feldspar. Biotite occurs as small mafic clots. CZsvd CZsvd - Metadacite: Dark gray to nearly black, aphanitic metadacite. Outcrops as large to medium-sized, highly resistant boulders on hillsides and creek bottoms in the northwestern portion of the Oxford study area. This unit has a distinct, but faint sulfur odor when fresh surfaces are broken due to a high concentration of finely crystalline and disseminated sulfide minerals, most commonly pyrite in hand sample. Contains phenocrysts of grey quartz, and plagioclase with lesser amounts of mafic and opaque minerals. Crosscutting relationships recognized in outcrop show that CZpbg and CZdito locally intrude this unit. CZpmd CZpmd - Porphyritic metadacite: White to tan aphanitic to porphyritic metadacite. Occurs as boulders on hillsides and hilltops across two distinctive, resistant topographic highs in the northwestern corner of the field area. Phenocrysts of gray quartz up to 7-9 mm are set in a finely crystalline felsic matrix. Locally, near the very top of the topographic highs in the northwest comer of the field area, this unit contains enclaves of CZsvd. CZab CZab - Meta-andesite and metabasalt: Fine-grained dark gray-green to black-green, melanocratic +/- quartz, chlorite, epidote, hornblende plagioclase rocks. Chlorite replaces hornblende, and epidote group minerals replace plagioclase. Accessory magnetite and quartz are common. Generally unfoliated; foliated varieties with aligned chlorite hornblende occur. "Boxworks” fabric defined by intersecting quartz-epidote veins is distinctive. Probably represent hypabyssal basalt and andesite intrusives, as well as very fine-grained equivalents of metadiorite and metagabbro units. Occurs commonly as enclaves within other intrusive rock units. Equivalent in part to the greenstone unit of Cook (1968), and mafic volcanic unit of Hadley (1974). CZabf ~ — 5 — Г PzRhc \ CZabf - Foliated equivalent of meta-andesite and metabasalt: Chlorite defines foliation surfaces and includes localized zones of +/- sericite, chlorite phyllite. CZphc - Chlorite schist, phyllite and phyllonite: Light green-gray to dark green, phyllitic rocks derived primarily from sheared intermediate and mafic intrusive rocks (CZdq, CZdi, CZab and CZdigb); includes chlorite, sericite phyllite and phyllonite; and, sericite, quartzo-feldspathic mylonite. Mylonitic fabric locally developed as mm-scale differentiated micaceous and quartzo- feldspathic laminae along with flattened and rotated polycrystalline quartz-plagioclase aggregates. Includes thin zones of foliated quartz metadiorite (CZdqf), hornblende metadiorite-metagabbro (CZgbdi) and metagabbro (CZgb). S-C composite fabric common, and highly fractured and brecciated varieties occur near the Fishing Creek fault. 6zphr ' ns 1 L CZphs - Sericite, quartz schist, phyllite and phyllonite: Light gray phyllitic rocks probably derived from sheared felsic intrusive rocks, and possibly felsic pyroclastic rocks. Mylonitic fabric locally developed as mm-scale differentiated micaceous and quartzo-feldspathic laminae along with flattened and rotated polycrystalline quartz-plagioclase aggregates. S-C composite fabric common. CZphcs' i i i CZphcs - Sericite, chlorite schist, phyllite, and phyllonite: Light gray-green phyllitic rocks probably derived from sheared intermediate intrusive rocks. Mylonitic fabric locally developed as mm-scale differentiated micaceous and quartzo-feldspathic laminae along with flattened and rotated polycrystalline quartz-plagioclase aggregates. S-C composite fabric common. REFERENCES: Allmendinger, R. W., Cardozo, N. C., and Fisher, D., 2013, Structural Geology Algorithms: Vectors & Tensors: Cambridge, England, Cambridge University Press, 289 pp. Cardozo, N., and Allmendinger, R. W., 2013, Spherical projections with OSXStereonet: Computers & Geosciences, v. 51, no. 0, p. 193 -205, doi: 10.1016/j.cageo.2012.07.021 Cook, J.T., 1968, The Geology of the Oxford area, Granville and Vance Counties, North Carolina, (M.S. thesis): Raleigh, North Carolina State University, 117 p. Hadley, J.B., 1973, Igneous rocks of the Oxford area, Granville County, North Carolina: American Journal of Science, Cooper v. 273-A, p. 217-233. LeMaitre, R.W., 2002, Igneous Rocks a classification and glossary of terms, 2nd edition, Recommendations of the International Union of Geological Sciences Subcommission on the systematics of igneous rocks. Cambridge, University Press, 236p. Parnell, D.B.; Blake, D.E.; Wooten, R.M.; Phillips, C.M.; Farris, P.F., 2006, Geologic map of the Oxford 7.5-minute quadrangle, Granville and Vance Counties, North Carolina: North Carolina Geological Survey Open-file Report 2006-01 , scale 1:24,000, in color. (Superseded by this map.) Parnell, D.P., 2012, Lithodemic, structural, and geochemical characterization of the northeastern Carolina terrane in the northern Oxford 7.5-minute quadrangle, North Carolina [M.S. thesis]: Wilmington, University of North Carolina Wilmington, 179 p. (http://dl.uncw.edu/etd/2012-1/parnelld/davidparnell.pdf) EXPLANATION OF MAP SYMBOLS Contacts INDEX TO GEOLOGIC MAPPING Jordan Coon Creek US 1 5 Creek - contact - inferred . shear zone contact contact - concealed brittle fault - inferred brittle fault - concealed [i cross section line qv "dike" CZpyba - porphyritic meta-andesite dike diabase dike - inferred diabase dike - concealed Faults - Solid where location known, dashed where inferred, dotted where concealed. For normal brittle faults, D indicates downthrown side, U indicates upthrown side. The tick mark indicates dip of fault plane. Zones of late brittle fracture and/or faulting; characterized by vuggy quartz and local brecciation indicated by dashed X lines. In cross section, fault displacement arrows show the inferred direction of the main, late stage ductile-brittle fault movement related to Mesozoic rifting. Structural Symbols Observation sites are centered on the strike bar or are at the intersection point of multiple symbols. ^■75 strike and dip of inclined foliation [ 76 strike and dip of spaced cleavage - 72 strike and dip of igneous contact FISHING CREEK FAULT ZONE This is an Open File Map. It has been reviewed internally for conformity with North Carolina Geological Survey mapping standards and with the North American Stratigraphic Code. Further revisions or corrections to this Open File map may occur. This map supersedes NCGS Open File Report 2006-01 . Edits to map include correction of edge- match issues, additional data, and modified unit interpretations from masters thesis of Parnell (2012). Research supported by the U.S. Geological Survey, National Cooperative Geologic Mapping Program under STATEMAP (Awards - 2001, 01HQAG0061; 2004, 04HQAG0059; 2005, 05HQAG0082) This map and explanatory information is submitted for publication with the understanding that the United States Government is authorized to reproduce and distribute reprints for governmental use. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either express or implied, of the U.S. Government. Compiled Geologic Map of the Oxford 7.5-Minute Quadrangle, Granville and Vance Counties, North Carolina By David B. Parnell, David E. Blake, Richard M. Wooten, Cindy M. Phillips, and Paul F. Farris Digital representation by Michael A. Medina, Norman K. Gay Cindy M. Phillips and Timothy W. Clark 2016 70i strike and dip of inclined foliation HI 45 (multiple observations at one location) -f strike of vertical foliation strike of vertical foliation (multiple observations at one location) 78 strike and dip of shear or shear foliation so | strike and dip of shear or shear foliation во (multiple observations at one location) T I T strike of vertical shear or shear foliation strike of vertical shear or shear foliation (multiple observations at one location) 82 strike and dip of inclined foliation within enclave I84 I strike and dip of mesoscale ductile fault strike of vertical mesoscale ductile fault Гео 1 strike and dip of spaced cleavage * I strike of vertica| jgneous contact I L65 (multiple observations at one location) 1 strike of vertical spaced cleavage t strike of vertical spaced cleavage (multiple observations at one location) ^ 62 strike and dip of joint ** 05 1 strike and dip of joint ** L 55 (multiple observations at one location) 49 l 34 21 ! 17 * t strike and dip of bedding strike and dip of fold axial plane (multiple observations at one location) strike and dip of brittle fault bearing and plunge of slickenline lineation bearing and plunge of fold axis strike of vertical joint ** strike of vertical joint ** (multiple observations at one location) 11 ^ bearing and plunge of mineral stretch lineation 19 bearing and plunge of intersection lineation d) horizontal joint ^ 81 strike and dip of fracture surface *** о strike of vertical fracture surface *** Д quartz breccia © station location without structural data 0^ whole-rock geochemical data location with map I.D. Special notes for symbols * Spaced Cleavage (Wooten)- Closely-spaced planar fracture surfaces typically with sericite and/or chlorite mineral growth. Locally with Fe-Mn oxide coating. Distinct from joints and foliation. ** Joints (Wooten) - Planar surfaces, locally with Fe-Mn oxide coating. *** Fracture Surface (Blake and Parnell) - Planar surfaces and fractures. Locally with Fe-Mn oxide coating. May include joints. Oxford 7.5-minute Quadrangle, Open File Report 2016-19