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GEOLOGIC MAP OF THE EFLAND 7.5-MINUTE QUADRANGLE, ORANGE COUNTY, NORTH CAROLINA T 0 H 0 E 6

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This geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program L A N D

7 . 5 - M I BY PHILIP J. BRADLEY, NORMAN K. GAY N U T

AND RANDY BECHTEL E

Q U

Digital representation by Michael A. Medina, Philip J. Bradley, and Norman K. Gay A D

DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES NORTH CAROLINA GEOLOGICAL SURVEY R A

2006 N DIVISION OF LAND RESOURCES OPEN FILE REPORT 2006-02 G L E ,

79 15' 00" 79 07' 30" DESCRIPTION OF MAP UNITS O R A

36 07' 30" 36 07' 30" All pre-Mesozoic rocks of the Efland quadrangle have been metamorphosed to at least the chlorite zone of the greenschist metamorphic N 86 G 74 79 87 63 86 Zmi 82 64 E Jd 81 68 facies. Many of the rocks display a weak or strong metamorphic foliation. Although subjected to metamorphism, the rocks retain relict 63 82 81

71 C 86 81 77 77 86 81 81 igneous, pyroclastic, and sedimentary textures and structures that allow for the identification of protolith rocks. As such, the prefix "meta" O 84 81 74 62 68 71 U 80 Zgd-gb 82 80 80 64 81 75 N 88 84 64 Zgd-gb 68 is not included in the nomenclature of the pre-Mesozoic rocks described in the quadrangle.

66 88 T 86 76

52 Y 53 65 Qal 74 32 22 89 78 74 , 85 80 72 68 63 80 N 68 62 82 86 71 Zat 82 78 The nomenclature of the International Union of Geological Sciences subcommission on igneous and volcanic rocks (IUGS) after O 80 75 69 86 72 68

Qal R 64 64 82 75 79 72 Streckeisen (1973 and 1979) is used in classification and naming of the units. The classification and naming of the rocks is based on relict T

74 H 78 82 Zft-e Ze/p Zat 79 Qal igneous textures, modal mineral assemblages, or normalized mineral assemblages when whole-rock geochemical data is available. Past C

62 A 57 Zft-e 88 74 81

78 workers in the Efland quadrangle (Butler, 1964; Allen and Wilson, 1968; and Newton, 1983) have used various nomenclature systems for R 89 70 80 88 84 O 69 79

Zat L Ze/p 75 70 80 the igneous rocks. The raw data of these earlier workers was recalculated and plotted on ternary diagrams and classified based on IUGS 79 I 83 86 75 N Zgd-gb 86 62 72 87 88 80 86 33 74 nomenclature. Pyroclastic rock terminology follows that of Fisher and Schminke (1984). A 66 65 76 76 85 80 46 63 Zgd-gb 81 Jd 81 75 88 78 Sedimentary Units 74 Qal 46 82 86 65 81 71 79 79 78 Zft-e Ze 66 73 Qal - Alluvium: Unconsolidated clay, silt, sand and gravel to cobble-sized clasts, subrounded to angular, deposited in drainages. 78 Qal 88 72 71 34 79 44 74 78 68 78 Zgd-gb 57 Qal 85 Zablt Intrusive and Meta-Intrusive Units 88 66 77 Zat 85 79 79 79 87 81 74 27 74 86 Qal 70 76 84 Jd - Olivine diabase: Black to greenish-black, fine- to medium-grained, dense, consists primarily of plagioclase, augite, and 66 87 74 Jd 71 82 olivine. Occurs as dikes up to 80 ft wide. Diabase typically occurs as spheriodally weathered boulders with a grayish-brown 87 88 Ze/p Zablt Qal 73 weathering rind. Red station location indicates outcrop or boulders of diabase. 80 86 Qal 82 78 75 Zmi 79 60 78 81 Zmi Zmi - Porphyritic mafic intrusive: Grayish-green to dark-green, very hard, plagioclase porphyritic mafic rock. Greenish-white, 80 88 85 79 Ze/p 71 86 euhedral, plagioclase phenocrysts (up to 8 mm) and black amphibole/pyroxene? phenocrysts (up to 2 mm) are present in a green 76 Qal 82 79 Ze 83 68 82 78 3 and yellow mottled, very fine-grained (less than 1 mm) matrix. Typically weathers to rounded boulders and outcrops. The Zdlt Zft-e 83 70 75 87 69 plagioclase phenocrysts weather in positive relief, creating a distinctive bumpy or pustulate surface. Newton (1983) identified 41 88 77 79 67 74 78 79 83 66 Zgd-gb 70 this unit as an amphibole-porphyry lamprophyre dike. 80 81 88 Qal 78 81 80 76 82 61 Zgr-di - Granite to diorite: Composite pluton exhibiting a variety of rock types ranging from granite to diorite. Lithologies include Zft-e 82 Zgr-di 54 60 74 74 Ze 88 60 grayish pink, medium- to coarse-grained granite; pinkish-white, medium-grained hornblende granodiorite; and dark-gray, fine- to Ze/p 88 80 45 Zgd-gb Ztgd 81 80 coarse-grained diorite. 72 Qal 65 76 81 66 85 69 66 64 81 86 Zgd - Granodiorite: Exhibits a variety of colors and textures ranging from yellowish-gray to grayish-white, medium- to 85 Zgd 72 72 70 70 83 A 81 67 82 coarse-grained hornblende granodiorite; contains dark-gray to light gray, fine to coarse-grained diorite. Ze/p 86 Zablt 78 64 53 Zdlt 74 Ze 53 76 74 71 86 63 52 74 81 83 76 76 Zgd-fine - Fine-grained granodiorite: Light-gray to green; ranges from equigranular fine-grained (less than 1 mm) granodiorite 84 76 84 85 74 Zgd-fine 75 50 55 81 72 78 Zgd-gb 88 79 63 87 83 Zablt 80 51 75 to very fine-grained porphyritic granodiorite with plagioclase phenocrysts (1 mm to 4 mm). Black colored amphibole, when visible, 89 86 76 87 80 77 74 69 77 83 Qal 69 85 7379 73 occurs as phenocrysts (less than 1 mm to 1 mm) and as intergrowths with plagioclase; amphibole intergrowths distinguish rock from 84 79 85 81 82 Zft-e 76 69 84 Qal 79 80 64 84 77 77 77 85 76 69 84 fine-grained tuffs. 81 7678 77 69 38 86 74 84 78 62 Zgd-leuco - Fine-grained leucocratic granodiorite: Small pods of tan to light-gray, fine-grained (less than 1 mm), leucocratic Qal 54 Zgd-leuco 71 granodiorite. Mafics present in rock are commonly biotite clusters up to 1 mm in diameter. Plagioglase mineral grains have a 82 80 83 79 86 87 light greenish tint from epidote growth. 83 16 70 Zft-d 73 83 69 27 71 78 89 82 13 Zft-d 78 74 84 61 75 Zagd-fine - Fine-grained altered granodiorite: Light-green, fine-grained (less than 1 mm), altered intrusive rock interpreted as a Qal 11 89 76 35 Zagd-fine 81 87 75 Qal 29 Zdlt Zft-d 78 70 76 78 74 78 65 71 65 86 80 82 56 granodiorite. Rock is primarily a fine-grained mass of heavily saussuritized plagioclase and quartz with no visible mafic minerals 78 70 83 76 76 55 79 Ze 86 67 16 7 74 79 7881 66 74 in hand sample. Unit occurs as angular boulders in two small map bodies. 76 Qal 71 80 78 67 68 77 83 67 84 78 71 78 Qal 89 13 72 64 76 52 11 87 77 81 74 88 73 86 55 64 Zgd-gb - Granodiorite to gabbro: Composite pluton of dominantly medium-grained, hornblende granodiorite; lesser amounts of 78 75 Zgd-gb 70 72 52 85 87 81 Zgd-gb Zgd-gb Zgd-fine 67 78 53 medium-grained hornblende diorite, plagioclase porphyritic granodiorite, fine-grained granodiorite, and diorite; minor amounts of 78 66 82 54 Zdi 85 66 87 fine-grained gabbro. Fine-grained granodiorite and diorite are typically green in hand sample from sausseritization of plagioclase. 88 70 40 Qal 78 59 76 83 Hornblende is typically altered to chlorite and actinolite masses. 41 70 82 76 Zablt 72 87 75 83 76 Qal 61 Ztgd - Tonolitic granodiorite: Small stock of distinctive, white to light gray, medium-grained leucocratic tonolitic granodiorite. D (?) 76 Qal 72 Qal Ztgd 81 87 78 78 75 86 Quartz content is greater than 15%. Mafics present in rock are most commonly biotite. Weathering of rock produces a very 86 U (?) 73 84 72 62 coarse sand. Qal 82 71 86 87 76 54 78 72 76 82 60 82 75 Zablt 65 56 78 87 88 83 77 55 Zft-e 58 82 86 77 73 79 81 84 Zablt 88 84 68 67 72 D (?) 66 74 84 Ze 81 81 86 86 83 74 68 73 Zdi - Diorite: Greenish-gray to gray, medium-grained, equigranular, hornblende diorite. Major minerals include plagioclase and 88 74 89 52 71 Zdi 75 84 55 74 65 81 80 34 53 74 78 75 77 U (?) 65 67 76 78 86 hornblende. Greenish-white plagioclase crystals compose up to 50% of the rock and are typically sericitized and saussuritized. 77 52 79 79 59 87 80 80 69 75 73 64 75 79 88 51 79 84 Zgd-fine 73 81 82 73 79 Hornblende is typically altered to chlorite and actinolite masses. 71 86 63 83 77 77 Zdi 88 19 84 81 Qal Qal 79 82 70 84 79 66 74 64 67 Qal 72 78 62 76 85 Qal 74 74 70 88 88 80 57 61 Zat Zdi/gd - Composite pluton of dominantly medium-grained hornblende diorite; lesser amounts of medium-grained hornblende 84 74 78 82 56 Zdi/gd 82 78 79 Qal 70 85 71 66 86 61 granodiorite, fine-grained granodiorite, porphyritic diorite with plagioclase phenocrysts; minor amounts of porphyritic granodiorite 55 78 74 Zft-e Zagd-fine 70 53 82 80 80 Qal 75 Zdi with plagioclase phenocrysts. 82 82 62 79 82 83 87 33 87 82 75 57 Zft-d 74 57 83 56 76 88 71 88 82 88 Zdi-fine - Fine-grained diorite: Small plutonic bodies of green, very fine-grained diorite. The rock is green in hand sample 77 86 81 82 87 80 70 Zdi-fine 80 Zgd-fine 86 64 77 69 Zablt from saussuritization of plagioclase. Zagd-fine 77 77 84 Zgd-gb 68 67 73 88 30 84 84 83 71 67 78 84Zablt 67 Zablt 81 76 70 71 Metavolcanic Units Zablt 84 64 Qal 77 70 28 76 Qal Zdlt 83 Zdi 60 68 87 69 71 Zat Zat - Altered tuffs: Very light-gray, light-greenish-gray to white, mottled red and yellow, altered, tuffs. Alteration of felsic tuffs 84 76 82 68 87 85 69 79 have produced sericite-quartz phyllite, pods of pyrophyllite, and quartz + pyrophyllite rock; all with common less than 1 mm to 68 Qal 80 89 86 84 76 58 86 79 Zft-d 80 81 Zablt Qal 85 Ze 80 78 85 82 81 68 2 mm diameter cubic pyrite aggregates and goethite-lined molds of pyrite crystals. Fine-grained porphyoblasts of chloritoid (less 76 75 77 78 80 79 82 70 63 70 67 86 Zablt 86 67 than 1 mm) and andalusite (up to 4 mm) are present in some pyrophyllite bearing rocks. Relict lithic clasts and kaolinitized 68 Zft-d 77 83 84 86 87 82 79 33 Zft-e 81 82 71 67 80 81 81 74 Zablt feldspar crystal shards are visible in some outcrops. Relict structures are obliterated in heavily altered rocks. A steep hill, west Zablt 76 76 84 66 72 87 87 85 87 78 56 68 80 of Occoneechee Mountain, is capped with a well-bedded, nodular, siliceous sinter mixed with pyrophyllite and massive 85 73 85 78 81 68 Zgd-fine Zdlt 70 86 83 77 85 82 72 82 88 80 quartzite-like rock interpreted to be a hydrothermal deposit. Qal 82 77 87 87 77 70 69 64 71 73 70 70 77 60 Zdlt 87 63 78 85 78 79 67 23 77 79 74 79 86 71 57 81 83 81 42 72 78 73 64 64 Ze/p - Mixed epiclastic-pyroclastics: Grayish-green to greenish-gray; tuffaceous sandstones, conglomeratic sandstones, siltstones 78 71 82 80 87 79 84 82 Ze/p 77 87 73 Zft-d 88 35 79 Zft-d 71 87 69 81 68 78 Zgr-di and minor phyllite. The siltstones typically are weakly phyllitic. Unit contains lesser amounts of coarse tuff and lapilli tuff. 82 40 77 80 64 74 74 36 Zablt 54 75 64 78 20 72 Abundant silicified and/or sericitized altered rock similar to Zat unit is present near contacts with plutonic rocks. 48 88 76 52 77 Qal 79 88 61 60 Zgd-fine 80 87 72 60 57 75 70 86 88 75 65 Qal 76 86 89 81 81 87 69 80 87 80 74 85 84 68 5475 77 38 57 75 83 47 71 75 80 70 75 Zdi Ze – Epiclastics: Mixed unit of metasedimentary rocks. Lithologies present include mudstone, siltstone, sandy siltstone, sandstone, Qal 88 89 82 Zdlt Ze 79 81 71 12 71 75 64 70 17 73 78 Zdlt 72 69 50 86 62 pebbly sandstone, and conglomerate. Mudstones are greenish-gray to gray, typically silicified, with continuous, parallel to slightly Zft-o 84 81 81 85 ) 77 88 80 Zablt 85 79 86 (? 82 88 47 75 85 77 89 88 84 ) 82 76 5978 32 wavy, very thin to medium lamina occasionally with small-scale loading structures. Siltstones are light green-gray to gray, with 76 88 81 74 80 82 U ? 87 Zablt Zablt ( 83 76 82 88 72 56 85 86 77 88 87 80 D 70 78 88 73 58 41 34 continuous, parallel to slightly wavy, thin lamina to very thin beds, occasionally with small-scale loading structures. The siltstones 78 75 64 77 81 75 66 73 83 89 82 54 88 82 81 84 58 Zablt 76 65 84 are composed of quartz, sericite, and traces of a black detrital heavy minerals (less than 1 mm in diameter). Siltstones are typically 56 Zft-d 81 87 87 72 88 Zft-o 74 76 Zablt 70 88 interbedded with the sandstones. Sandstones are dark-gray, gray, greenish-gray, grayish-green, litharenites and feldspathic 88 74 81 87 Zdlt 85 76 72 78 Zablt 78 73 litharenites composed of volcanic rock fragments, feldspar, quartz, and rare intrusive rock fragments. Textures range from 68 36 81 87 83 78 Zablt 59 Zablt 66 Qal 78 89 81 85 fine-grained, and well sorted to very coarse-grained, and moderately poorly sorted. Bedding in the sandstones is continuous, Zablt 77 84 77 76 86 59 66 68 77 78 85 Zablt 71 73 83 76 89 63 Zgd parallel to inclined, thin lamina to thin beds; also massive bedding and cross-beds are present. Individual beds are sometimes 58 80 82 75 87 88 88 87 79 75 77 87 77 51 83 Ze 84 88 67 75 78 50 88 graded from sand-size to silt-size with abrupt upper surfaces. Conglomerates include matrix supported and clast supported 55 Qal 84 86 70 70 85 86 79 73 71 68 85 47 82 49 88 62 81 82 77 44 80 76 84 64 polymictic conglomerate composed of angular to rounded, pebbles to large cobbles (up to 30 cm). Conglomerates are generally 62 76 76 78 86 86 84 57 53 82 83 78 86 87 79 64 62 85 17 77 Ze massive bedded, rarely with any imbrication of the clasts. Clast types include: dark-gray to gray, angular to subangular, 31 82 69 82 81 83 55 77 78 81 82 60 73 80 86 78 82 79 86 81 82 81 88 89 75 77 54 72 66 microcrystalline volcanic rock fragments; black, subangular to subrounded, plagioclase-porphyritic dacite; black to dark gray, Zft-o 77 Zdi 77 62 71 78 72 66 34 87 64 76 77 81 78 83 48 53 64 82 74 subrounded, flow-banded dacite; and greenish-gray to grayish-green, rounded to well rounded, fine to coarse plagioclase crystal Zablt 37 81 42 82 Zablt 59 64 76 87 79 80 61 79 68 87 65 Zdlt 78 tuff. Rare clast types include: white, subangular to rounded, granite and granodiorite (up to 12 cm); dark-brown, rounded, 82 83 89 81 89 80 Zablt 75 75 33 75 82 78 83 77 vesicular basalt (up to 2.5 cm); and gray, angular siltstone (up to 25 cm). Sandstone and conglomerate beds often fill scour Zablt 87 62 81 47 77 65 88 71 69 82 46 79 82 67 Zablt 87 57 71 Zgd-fine 87 75 78 channels in the siltstones. Metasedimentary units are interpreted to be correlative with the Aaron Formation of Glover and 63 78 72 69 67 72 86 71 Sinha (1973). The Aaron Formation has been interpreted as a submarine-fan deposit in a deep marine basin marginal to or 55 84 66 87 85 70 80 82 74 54 68 75 6874 86 65 88 Zdlt superimposed on a formerly active volcanic arc (Harris, 1984). Zablt 88 53 87 87 88 64 73 82 80 81 Qal 85 80 78 58 50 64 69 63 83 87 73 85 85 75 63 78 71 60 64 59 85 Zft-e - Felsic tuff of the Efland area: Light-green to grayish-green and greenish-gray to gray; massive to strongly foliated; fine to Zft-o 76 76 87 71 Zablt 74 Zft-e 81 85 66 14 Zdi-fine 65 65 80 76 80 76 62 68 87 68 85 77 83 77 coarse felsic tuffs. Coarse plagioclase crystal tuff, and welded tuffs are common with lesser amounts of lapilli tuff with clasts up 82 73 71 Zgd-leuco 81 88 45 72 32 55 61 75 83 44 77 81 85 50 77 81 89 78 to 12.5 cm. Interlayers of tuffaceous sandstones are locally present. 82 41 76 65 87 64 89 Qal 79 73 81 71 Zablt 86 81 77 77 80 75 61 71 64 75 64 74 74 61 60 83 62 86 87 Ze 64 70 86 80 7659 Zgd-leuco 77 46 16 82 86 83 49 85 80 82 Zft-o - Felsic tuff of Oak Grove Church area: Gray, greenish-gray, grayish-green; massive to strongly foliated; fine to coarse Jd 78 74 86 72 80 87 65 58 77 Zft-o 84 Zdlt 77 71 70 77 82 79 75 78 51 felsic tuffs. Plagioclase crystal fragment-rich coarse tuff, lithic tuff and welded tuff are common. Minor quartz crystal tuff. 84 Zdlt Zgd 66 58 68 77 74 79 86 89 84 87 41 86 84 Qal 77 88 Minor amounts of interlayered epiclastic rocks are present. 65 75 74 86 80 78 64 74 87 87 81 87 Zgd-fine 81 Qal 77 75 85 75 85 67 87 74 78 87 Zablt 58 69 77 Ze 71 Zgd-fine 74 70 88 87 61 71 73 85 57 84 47 Zft-d - Felsic tuffs of the Duke quarry area: Unit consists of massive to strongly foliated: greenish-gray to grayish-green, coarse 81 77 83 67 66 78 Zft-d 75 79 60 Zablt Zgd-fine 81 84 65 Zablt 47 plagioclase crystal tuff; light-green, welded, lapilli-bearing, plagioclase + quartz crystal tuff; greenish-gray to grayish-green, 77 76 88 71 Zat 82 Qal 68 80 74 84 Qal 81 78 88 65 81 71 Zdlt 61 86 74 84 77 75 matrix supported lithic tuff; and gray microcrystalline ash tuff with pyrite. Minor lithologies include interlayers of amygdaloidal Qal 77 87 69 48 74 69 88 73 72 69 87 Qal 73 96 58 75 50 68 86 89 67 58 71 82 63 80 87 63 72 basalt, fine-grained mafic tuffs that have been altered to epidote/chlorite, and epiclastic rocks. 71 83 70 56 57 67 78 82 87 88 89 66 71 82 Ze 86 81 74 87 85 Zdi-fine 78 88 79 75 72 84 80 87 36 00' 77 36 00' 87 46 74 66 In the Duke quarry area the unit is characterized by foliated phyllitic tuffs, matrix supported lapilli tuff, tuffaceous sandstone, and 79 15' A' 79 07' 30" siltstones. Relict sedimentary structures preserved in the Duke quarry area include lamina and beds, small-scale load structures, and normally graded bedding. Lithic clasts display an apparent flattening parallel to foliation and are commonly altered to quartz and CONTACTS sericite. Chloritoid porphyroplasts are locally present. Southwest of Duke quarry, in the Carrington Farm and Chestnut Ridge Church 0.25 0.125 0 0.25 0.5 0.75 1 MN Miles Lithologic contacts - Distribution and concentration area, the rocks are strongly foliated, dark gray, very resistant, with or without apparently flattened clasts, siliceous phyllites. All primary GN Bradley of structural symbols indicates degree of reliability. structures have been obliterated. 1,250 625 0 1,250 2,500 3,750 5,000 8 1/2 geologic contact 1 04' Feet Zdlt - Dacitic lavas and tuffs: Distinctive dark-gray to black, siliceous, cryptocrystalline dacite, porphyritic dacite with plagioclase 151 MILS Zdlt 19 MILS concealed geologic contact phenocrysts, and flow banded dacite. Tuffs associated with the lavas include welded and non-welded: greenish-gray to Gay 375 187.5 0 375 750 1,125 1,500 1:24,000 SCALE Quaternary alluvium contact grayish-green, coarse plagioclase crystal tuff; lapilli tuff; lithic tuff. Welded lapilli tuff often contains black-colored fiamme, Meters CONTOUR INTERVAL 10 FEET UTM GRID AND 2002 MAGNETIC NORTH D (?) fault - D (?) indicates suspected downthrown side, up to 10 cm, interpreted as flattened pumice and coarse plagioclase crystal fragments. Massive, matrix supported lithic tuff Bechtel DECLINATION AT CENTER OF SHEET Base topographic map is digital raster graphic image U (?) U (?) indicates suspected upthrown side contains angular to rounded, polymictic clasts up to 8 cm. Clast types include: gray and green, microcrystalline to coarse-grained of the Efland 7.5 minute USGS quadrangle (1994), inferred fold axis of major- and volcanic rock fragments; black porphyritic lava with plagioclase phenocrysts; and black flow-banded dacite. Minor interlayers of INDEX TO GEOLOGIC MAPPING North Carolina State Plane NAD 83 meters coordinate system. minor-scale overturned syncline microcrystalline ash tuff are present. Small map-scale bodies of mafic tuff and lava; coarse-grained, cross-bedded, litharenite major minor sandstone; and polymictic, pebble and small cobble conglomerate are present in unit. The dacites are interpreted to have been inferred fold axis of minor-scale LOCATION OF THE EFLAND 7.5-MINUTE coherent magma that were extrusive or very shallow intrusions associated with dome formation. The tuffs are interpreted as QUADRANGLE, NORTH CAROLINA overturned anticline minor episodic pyroclastic flow deposits, air fall tuffs or reworked tuffs generated during formation of dacite domes. I-77 I-85 I-95 STRUCTURAL SYMBOLS Zablt - Andesitic to basaltic lavas and tuffs: Green, gray-green, black; amygdaloidal basalt, porphyritic basalt with plagioclase Observation sites are centered on the strike bar Zablt I-40 or are at the intersection point of multiple symbols. phenocrysts, porphyritic basalt with amphibole/pyroxene phenocrysts, and microcrystalline basalt. Tuffs associated with the

23 strike and dip of primary vertical primary bedding lavas include: coarse plagioclase crystal tuff, with suasseritized pale green, angular to subrounded plagioclase crystal fragments bedding and layering and layering (up to 3 mm) in a fine-grain matrix of epidote and chlorite; coarse amphibole/pyroxene crystal tuff with black, prismatic I-26 I-85 I-77 19 strike and dip of 70 strike and dip of amphibole/pyroxene crystal fragments (up to 3 mm) in a fine-grain matrix of epidote and chlorite. Rounded weathering patterns of normal bedding overturned bedding outcrops and amoeboid shaped structures in outcrop of some mafic lavas are interpreted as possible pillow structures. Basalts are I-95 34 strike and dip of primary volcanic vertical strike of primary volcanic interpreted to be lava flows or shallow intrusions. Stereonet - Contoured Poles to Foliation, Cleavage, Unidirectional Rose Diagram of Foliations, Cleavage, Unidirectional Rose Diagram of Joints N=958 I-40 Spaced Cleavage, and Shear Foliation N=532 Spaced Cleavage, and Shear Foliations N=532 compaction and/or welding compaction and/or welding References: 17 strike and dip of primary 51 strike and dip of volcanic flow banding spaced cleavage Geology mapped from August 2005 through May 2006. Allen, E.P. and Wilson, W.F., 1968, Geology and mineral resources of Orange County, North Carolina: Division of Mineral Resources, North Carolina Department of 41 strike and dip of cleavage vertical cleavage Conservation and Development, Bulletin 81, 58p. Butler, J.R., 1964, Chemical analyses of rocks of the Carolina Slate belt, Southeastern Geology, v. 5, p. 101-112. 34 strike and dip Disclaimer: vertical foliation Fisher, R.V. and Schmincke H.-U., 1984, Pyroclastic rocks, Berlin, West Germany, Springer-Verlag, 472p. of foliation This Open-File report is preliminary and has not been reviewed Glover, L. and Sinha, A., 1973, The Virgilina deformation, a late Precambrian to Early Cambrian (?) orogenic event in the central Piedmont of Virginia and North 22 for conformity with the North Carolina Geological Survey editorial strike and dip of joint vertical joint Carolina. American Journal Science, 273-A, p. 234-251. standards or with the North American Stratigraphic Code. Further Harris, C., and Glover, 1988, The regional extent of the ca. 600 Ma Virgilina deformation: implications of stratigraphic correlation in the Carolina terrane, Geological 22 strike and dip of shear foliation vertical shear foliation revisions or corrections to this preliminary map may occur prior to Society of America Bulletin, v. 100, pp. 200-217. Harris, C.W., 1984, Coarse-grained submarine-fan deposits of magmatic arc affinity in the Late Precambrian Aaron Formation, North Carolina, U.S.A.: Precambrian 41 its release as a North Carolina Geological Survey map. trend and plunge of 44 trend and plunge of Research, V. 26, p. 285-306. crenulation lineation clast lineation McConnell, K.I. and Glover, L., 1982, Age and emplacement of the Flat River complex, an Eocambrian sub-volcanic pluton near Durham, North Carolina, Geological 19 Society of America, Special Paper 191, p. 133-143. Research supported by the U.S. Geological Survey, National Cooperative trend and plunge of 36 trend and plunge of Newton, M.C., 1983, A late Precambrian resurgent cauldron in the Carolina slate belt of North Carolina, U.S.A., M.S. thesis, Virginia Polytechnic Institute and State University, 89p. Stereonet - Contoured Poles to Primary Layering, Bedding, Unidirectional Rose Diagram of Primary Layering, Bedding, QAP PLOT OF NORMALIZED WHOLE ROCK Geologic Mapping Program, under USGS award number 05HQAG0082. mineral lineation slickenline lineation Welding/Compaction Foliation, and Flow Banding N=311 Welding/Compaction Foliation, and Flow Banding N=311 ANALYSES OF FINE-GRAINED ROCKS OF PAST 11 Streckeisen, A.L., 1973, Plutonic rocks: Classification and nomenclature recommended by the IUGS subcommission on the systematics of igneous rocks: Geotimes, v. 18, p. 26-31. WORKERS AND THIS STUDY FOR THE EFLAND The views and conclusions contained in this document are those of the trend and plunge station location Streckeisen, A.L., 1979, Classification and nomenclature of volcanic rocks, lamprophyres, carbonatites, and melilitic: Recommendations and suggestions of the IUGS QUADRANGLE (ALLEN AND WILSON (1968), of lineation BUTLER (1964) AND NEWTON (1983)). authors and should not be interpreted as necessarily representing the subcommission on the systemics of igneous rocks, Geology, v. 7, p. 331-335. official policies, either expressed or implied, of the U.S. Government. active quarry location inactive quarry location

A Seven Mile Mt. Willing Orange Grove A' I-85 Buckhorn Rd. Creek Road Road

750' 750' Zgd-fine 0' ? 0' Zablt Ze/p Zft-d Zgd-gb Ze ? Zft-o Ze Zablt Zft-d ? Zdlt ? Zablt is s y -2000' -2,000' h p Zft-o o Ze p Ze/p a ? Ze Ze

no vertical exaggeration Scan with smartphone for link measurement in feet to GeoPDF of map. Schematic representation of relationships reference mean sea level Third party App required. of geologic units in the Efland quadrangle scale 1:24,000