North Carolina Department of Environmental Quality North ... Mineral and Land...Geology by David E....
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US 1 HORSE CREEK SR 1925 SR 1909 MUD BRANCH SR 1922 SR 1915 LOWERY CREEK SR 1917 WEST EAS T 0 CZfu CZfs CZfu CZfu CZfu CZrl PzZgg CZfs CZbg CZmcg CZflg CZrgn Jd Jd DUCTILE THRUST FAULT DUCTILE FAULT A T A A' Qal Qal 45 44 56 55 45 61 82 57 57 54 62 49 63 68 66 52 65 71 44 45 52 41 48 41 67 65 48 71 65 55 75 55 78 82 70 60 23 85 15 83 1 67 54 35 5 52 10 0 28 25 3 6 10 5 7 35 40 82 57 72 77 76 70 65 51 2 5 72 72 51 78 76 70 45 45 28 56 49 47 44 33 35 23 16 12 13 31 15 16 4 22 10 47 29 22 11 12 41 37 36 50 47 75 68 57 45 44 18 4 7 7 6 60 20 64 23 17 10 26 14 1 17 14 3 2 4 10 38 34 13 10 26 5 23 78 59 64 87 81 63 81 75 88 65 47 68 51 72 74 65 71 70 79 57 72 53 72 57 79 85 72 75 64 82 85 45 55 53 80 34 43 39 59 68 30 70 46 40 48 54 40 47 58 72 50 55 48 58 70 49 40 42 55 39 35 83 78 59 72 57 66 42 29 35 62 63 66 50 80 60 58 72 74 55 67 79 57 45 63 74 51 67 34 66 54 46 35 64 71 68 43 48 55 54 65 48 50 42 33 50 42 41 48 25 32 37 38 30 20 31 50 40 10 50 53 37 35 21 63 35 21 33 23 36 32 47 19 61 33 35 31 28 56 27 30 15 20 88 12 19 6 27 9 22 63 47 52 49 30 30 32 30 38 30 35 45 46 36 40 42 27 45 51 47 56 41 51 62 51 62 55 47 62 44 60 60 49 52 58 68 56 44 54 60 75 61 61 44 24 47 60 76 80 71 78 35 60 53 78 60 60 45 64 47 57 64 78 48 60 54 56 66 88 75 60 59 23 44 60 69 65 77 78 69 79 56 63 59 88 63 60 52 38 47 50 52 54 57 53 56 49 55 36 64 47 23 63 47 60 58 53 40 56 42 62 49 55 71 56 57 44 43 30 47 24 24 54 36 38 50 37 70 34 36 29 9 6 25 30 12 46 36 25 26 23 18 14 21 21 29 22 13 11 18 63 37 32 49 44 36 10 55 38 48 53 25 54 65 23 10 21 24 12 20 24 23 18 9 24 28 25 40 20 25 8 11 4 41 42 48 60 89 72 74 55 45 57 50 40 45 53 51 49 60 53 37 31 47 27 43 47 48 50 50 78 60 48 24 82 80 69 48 68 77 68 72 51 58 73 68 66 70 66 33 42 22 27 37 50 48 41 32 70 48 74 79 38 55 65 47 26 53 22 50 60 45 61 54 56 57 67 56 84 62 80 54 59 63 49 60 53 33 50 36 57 79 37 42 27 57 78 40 87 76 70 78 86 80 78 74 87 71 65 79 59 27 47 41 30 23 15 47 45 33 18 17 78 18 88 21 46 52 8 10 31 27 29 34 35 29 55 25 36 17 35 55 24 25 44 47 37 53 54 26 55 59 75 25 58 38 52 15 44 35 49 57 87 65 49 36 52 45 54 52 26 47 44 45 30 35 35 39 33 35 47 61 45 19 12 43 37 33 55 73 50 42 62 48 48 71 33 61 46 49 64 81 81 77 63 72 39 64 53 40 53 43 58 54 48 68 52 52 59 70 48 62 63 44 60 36 39 55 44 33 47 44 65 65 24 54 89 82 89 80 62 35 62 62 39 32 23 48 35 28 37 42 42 47 43 69 44 68 58 52 70 27 30 20 20 5 12 33 30 20 7 24 11 19 17 24 23 33 75 76 70 60 18 26 30 34 20 30 21 23 26 33 12 31 22 18 20 26 37 69 72 30 63 35 58 51 42 50 40 25 31 37 43 72 55 74 65 68 86 83 40 28 25 17 46 74 63 18 70 84 86 31 38 38 72 34 83 59 57 87 36 70 85 60 26 45 73 62 60 77 60 70 30 57 35 48 83 44 87 51 60 55 85 67 40 60 60 26 43 74 60 48 55 42 44 36 64 72 89 80 66 66 18 74 11 72 79 74 83 79 88 86 89 61 52 68 88 55 72 74 50 83 88 82 82 80 77 40 75 80 80 82 81 80 73 65 48 70 66 58 61 88 65 65 79 55 69 50 62 79 84 71 69 60 73 62 74 75 89 70 74 45 83 70 75 79 70 68 75 69 70 66 50 70 45 40 71 50 55 58 40 60 80 88 77 65 55 82 60 81 88 73 75 75 75 64 72 72 74 37 32 55 40 59 78 66 88 61 60 62 63 70 64 89 89 70 52 50 60 64 70 50 50 72 75 60 57 70 50 70 45 55 67 75 52 40 60 65 65 60 84 62 75 55 20 23 50 69 85 75 40 46 54 45 54 45 40 50 45 49 54 37 30 72 38 26 39 45 52 49 63 40 62 70 60 59 55 45 54 48 48 88 48 72 79 77 50 80 82 89 81 76 88 75 72 51 88 80 77 30 30 59 61 76 60 53 51 30 72 80 77 48 22 30 60 20 44 5 48 49 54 56 30 74 88 77 57 76 45 67 80 65 79 83 80 69 80 76 60 80 76 85 72 75 46 66 70 47 67 67 49 73 59 48 85 65 88 67 70 88 59 84 83 84 73 60 52 69 58 62 50 55 72 86 85 54 78 16 80 75 70 75 61 77 50 64 81 65 69 8 73 46 68 CZfa PPccg Qal Qal Qal Qal Qal Qal Qal CZmcg CZfs CZfs CZbp Trcs/c CZct CZfu CZmcg CZmg CZmg CZmcg CZflg CZflg CZmcg Jd Jd Jd Jd Jd Jd Jd Jd Jd Jd Jd p p p p p p p p p p CZrgn CZhg CZmgs CZbg CZrgn CZfu CZfu CZfa CZfu CZfu CZfu CZfa CZfu CZfu CZfa CZfs CZhg Qal Qal Qal Qal Qal Qal Qal Qal Qal Qal Qal Cpu CZfua Trsb CZrgn CZfa CZhg CZmcg CZfa CZfu CZhg CZfu CZflg CZrgn CZflg CZfs CZfa CZfu CZfu CZfa CZmcg p CZfs CZfs DUCTILE STRIKE-SLIP FAULT CZfa CZfu Trcc CZmcg CZfu CZfs CZbg CZmcg CZflg Trsb Trcc Trcc CZgc CZcwq CZrl CZrl PzZgg CZfut CZfut CZfa CZfu CZfa CZfu CZfu CZfu CZhg CZmcg CZfu CZfut CZfu CZfu CZfu CZfu CZfa CZfu CZfu CZfu CZfu CZfa CZfu CZmcg CZfu CZfqz 25 70 80 55 8 CZfu CZmca CZmca Jd Jd Jd CZfa CZfa A' A Trcs/si2 Qal Qal Jd CZrgn CZfs Trcs/c Trcc Qal Trcs/si2 Trcs/si2 Trcs/si2 Trcs/si2 CZrgn FISHING CREEK FAULT DUCTILE STRIKE-SLIP FAULT DUCTILE THRUST FAULT DUCTILE THRUST FAULT J O N E S B O R OF A U LT JONESBORO FAULT CZfu PPccg 79 47 43 37 66 80 46 62 76 83 68 65 CZfs CZfs CZfs CZfs U M- 3 - 13 U M- 3 - 1 GS - 39 GS - 46 GS - 56 CZhg 36 00' 00" 36 07' 30" 78 37' 30" GEOL OGI C MAP OF THE GRI SSOM 7 . 5 - MI NU TE QU ADRANGL E , GRANV I LLE , FRANKL I N, AND WAKE COU NTI ES, NORT H CAROL I NA Geology by David E. Blake, Cindy M. Phillips, Benjamin D. Grosser, Kenneth R. Robitaille and Channa Witanachchi. 2016 Also incorporating previous mapping by Blake (1986) and Horton and others (1992). Digital representation by Michael A. Medina and Cindy M. Phillips 78 30' 00" 36 07' 30" 78 37' 30" 36 00' 00" 78 30' 00" Schmidt net equal-area plot of contoured poles to regional foliation (n = 909) Schmidt net equal-area plot of contoured poles to shear foliation (n = 103) Schmidt net equal-area plot of contoured mineral, elongation, and stretch lineations (n = 65) Unidirectional Rose Diagram of Joints N = 61 Base topographic map is digital raster graphic image of the Grissom 7.5-minute USGS quadrangle (1987). Geology compiled from Blake (1986), Horton et al. (1992), Robitalle (2004), and data collected by NCGS staff in 2001-2002. Partially supported by the USGS National Cooperative Mapping Program EDMAP and STATEMAP components. Mapping and research of Robitalle (2004) supported by EDMAP. Mapping by NCGS staff partially supported by STATEMAP grants 01HQAG0061 (2001) and 02HQAG0043 (2002). Disclaimer: This Open-File report is preliminary and has been reviewed for conformity with the North Carolina Geological Survey editorial standards or with the North American Stratigraphic Code. Further revisions or corrections to this map may occur. NORTH CAROLINA CZfa CZhg PPccg Trcs/c Trcc Trcs/si 2 CZfu CZfut CZfua CZfqz Cpu PzZgg Qa l - Qua t erna ry al uvium : Unconsolidated, poorly-sorted and poorly stratified, tan to light gray deposits of gravel, sand, silt, and clay. Similar to stratified terraces along streams. Cpu - Coa s t al P l ai n sedimen t s , undi fferen t i at ed: Unconsolidated, fine to coarse-grained, tan to light gray arkosic sands and clayey sands with occasional gravel. Trcc - congl om erat e: Reddish-brown to dark brown, irregularly bedded, poorly sorted, cobble to boulder conglomerate. Muscovite is rare to absent in the very coarse-grained to gravelly matrix. An arbitrary cut-off of greater than 50 percent conglomerate distinguishes this unit from the Trcs/c facies. Clasts are chiefly miscellaneous felsic and intermediate metavolcanic rocks, quartz, epidote, bluish- gray quartz crystal tuff, muscovite schist, and rare meta-granitic material. T rcs / c - sa nds t one wit h i n t erbedded conglom era t e: Reddish-brown to dark brown, irregularly bedded, poorly sorted, coarse-grained to pebbly, muddy lithic sandstones with interbedded pebble to cobble conglomerate. Muscovite is rare to absent in the matrix. Well-defined conglomerate beds distinguish this unit from conglomerate basal lags of Trcs. An arbitrary cut-off of less than 50 percent conglomerate distinguishes this unit from the Trcc conglomerate facies. Conglomerate beds are channel-shaped and scour into the underlying sandstone beds. Unit grades eastward into Trcc. T rcs / s i 2 - sands t one w/ i n t erbedded s i l t s t one: Cyclical depositional sequences of whitish-yellow to grayish-pink to pale red, coarse- to very coarse-grained, trough cross-bedded lithic arkose that fines upward through yellow to reddish-brown, medium- to fine-grained sandstone, to reddish-brown, burrowed and rooted siltstone. Bioturbation is usually surrounded by greenish- blue to gray reduction halos. Coarse-grained portions contain abundant muscovite, and basal gravel lags consist of clasts of quartz, bluish-gray quartz crystal tuff, and mudstone rip-ups. Trsb - s i li ci fi ed brecci a: Light gray to white, silicified rock that has been multiply brecciated and annealed. Contains angular clasts of probable pre-Triassic rock along the Jonesboro fault. Jd - diabase di kes : Steeply dipping to vertical dikes of gray to bluish-black, fine- to medium-grained, locally porphyritic plagioclase diabase, that may be olivine-bearing. Solid lines where observed; dashed lines where inferred from correlation and aeromagnetic data. PPccg Gra n it e o f t he Ceda r Creek p lut on : Pink-white, medium to coarse-grained, unfoliated to moderately foliated and lineated biotite granite, with local pegmatite. p - pegm at it e: Gray-white to pink-white, very coarse grained, microcline, plagioclase, quartz, muscovite, biotite pegmatite of the Rolesville granite. Some outcrops exhibit a graphic texture. PzZgg - gnei ss ic bi o t i t e gra n i t o i d ( Pal eozo i c? ) : Foliated biotite granitoid and granitoid orthogneiss interlayered with Raleigh gneiss. CZgc - Gi bbs Creek p l ut on : Light green to gray-green, fine- to medium-grained, leucocratic (CI less than 20) biotite +- hornblende metagranodiorite. Locally contains planar zones of dark green to gray-green, fine-grained, well foliated and lineated, chlorite phyllite having a phyllonitic fabric. CZct - Ca ro l i na t erra ne m et a gra n i t o i d: Orange-tan to pinkish tan, fine- to medium-grained, highly fractured, leucocratic (CI generally less than 5), biotite-bearing metatrondjhemite to metagranodiorite. Locally, biotite can increase in abundance and or be replaced by chlorite. Gray to bluish gray quartz phenocrysts are conspicuous, and the metagranitoid is locally porphyritic. Zones of silicification and pyritization are present. CZ bp - Bea verda m sui t e: Mixed assemblage of biotite- and hornblende-biotite metadiorite; hornblende metagabbro; and metapyroxenite. CZ fs - Fa ls L a ke schi s t : Variably gray colored, mesocratic, medium- to coarse-grained, biotite-white mica-oligoclase-quartz schist locally having garnet, staurolite, kyanite, and chlorite porphyroblasts. Contains pods of gabbro, amphibolite, and undivided ultramafic rocks. CZ fu - ult ram afic rocks ( undi vi ded) : Variably altered ultramafic rocks including metapyroxenite, actinolite-chlorite schist, and talc schist. CZfa - am phibo li t e: Dark gray, fine- to medium-grained, and well foliated amphibolite. CZhg - ho rnbl ende gnei ss : Dark gray to black, medium grained, poorly to moderately foliated hornblende-plagioclase gneiss and amphibolite. May contain biotite or epidote. Where biotite content is high may be somewhat schistose. CZ fut - t al c schis t : White to gray talc-tremolite schist, talc-chlorite schist, and soapstone. Rhombohedral cavities suggest former presence of a carbonate mineral (ankerite?). CZmg - m et a ga bbro : Light green to blue green, fine- to medium-grained, massive metagabbro containing relict plagioclase and hornblende, and metamorphic actinolite, epidote, and opaque minerals. CZ fqz - qua rt z it e: White, granular, and well foliated quartzite. CZ fua - a ct ino li t e rock and a ct i no li t e- chl ori t e schis t : dark green, schistose to almost massive, splintery rock composed of actinolite and varied amounts of chlorite; minor amounts of talc and magnetite octrahedra are common. Descri p t i on o f Ma p Un it s S urfici al Un i t s Pliocene (?) Quaternary Newa rk S upergroup , Cha t ha m Group Late Triassic I n t rus i ve Rocks Jurassic Pennsylvanian Neo-Proterozic to Late Paleozoic Met am orphi c Rocks CAROL I NA T ERRANE FALLSLAKE T ERRANE CRABT REE T ERRANE Neo-Proterozoic to Cambrian Trsb CZgc CZct CZbp CZfs CZmg CZbg CZmgs CZcwq CZmcg - Middle Creek gneiss : Fine- to coarse-grained, gneissic to schistose, locally lineated, mesocratic (CI less than 30), biotite quartz dioritic to granodioritic gneiss. Interlayered with pink-gray to orange-tan, fine- to medium-grained, locally lineated, leucocratic (CI less than 10), white mica biotite granitoid gneiss, and fine- to medium-grained amphibolitic gneiss. Also occurs as tectonic windows within Falls Lake terrane. CZbg - bi o t it e banded gnei ss : White, gray, and black, compositional layered and well foliated, biotite-quartz-plagioclase gneiss. CZmgs - m ixed gneiss and schi s t : Complex assemblage of highly intercalated gneissic and schistose rocks. Includes quartzofeldspathic gneiss, compositionally layered gneiss, quartz ribbon gneiss, amphibolite, hornblende gneiss, hornblendite, banded biotite gneiss, muscovite schist, muscovite-garnet gneiss, biotite-muscovite-garnet schist, talc schist, and quartzite. CZ cwq - Whi t e mi ca - ri ch and quart z- ri ch schis t : gold-gray to silver-gray, very fine- to fine-grained, moderately well foliated quartz-biotite and/or chlorite-white mica schist containing sparse to abundant garnet interlayered with silver-white, fine- to medium grained, moderately foliated white mica-plagioclase-quartz schist. CZmcg CZrl CZhg CZ fl g - Fal s leucogneis : Leucocratic (CI less than 5) pink-gray to orange-tan, medium-grained, weakly to moderately foliated and strongly lineated, biotite magnetite granitic gneiss. CZ rgn - Ra leigh gnei ss : Mixed unit consisting mainly of fine- to coarse-grained, well foliated, compositionally banded, and locally lineated biotite granitoid gneiss, and lesser amounts of biotite + hornblende gneiss, biotite schist, white mica schist, and amphibolite. CZhg - ho rnbl ende gnei ss : Dark gray to black, medium grained, poorly to moderately foliated hornblende-plagioclase gneiss and amphibolite. May contain biotite or epidote. Where biotite content is high may be somewhat schistose. CZ rl - fine- gra ined l eucocra t i c gnei ss : Very light gray, fine-grained, leucocratic epidote-plagioclase-quartz gneiss, locally containing darker, hornblende-bearing interlayers. RAL E I GH T ERRANE CZflg CZrgn Qal Jd p CZmca CZmca - Middle Creek gneiss , m afi c fa ci es : Dark grayish-black to dark green, fine- to medium-grained, foliated and lineated, layered, epidote-bearing hornblende gneiss to aphibolite. Locally contains opaque mineral-rich metapyroxenite. Blake, D.E., 1986, The geology of the Grissom area, Franklin, Granville, and Wake Counties, North Carolina: A structural and metamorphic analyses [M.S. thesis]: Raleigh, North Carolina State University, 300 p. Horton, J.W., Jr., Blake, D.E., Wylie, A.S., Jr., and Stoddard, E.F., 1992, Geologic map of the Falls Lake - Wake Forest area, north-central North Carolina: U.S. Geological Survey Open File Report 92-269, scale 1:24,000, 9 p. REFERENCES Robitaille, K. R., 2004, Geology and terrane relationships of the Tar River area, Franklin and Granville Counties, North Carolina, Unpublished M.S. Thesis, Wilmington, University of North Carolina at Wilmington, 167p. bearing and plunge of slickenline bearing and plunge of mineral lineation bearing and plunge of minor fold hinge (F 2 ) bearing and plunge of minor fold hinge (F 3 ) bearing and plunge of minor fold hinge (F 4 ) contact - location inferred contact - location concealed CONT ACT S Lithologic contacts - Distribution and concentration of structural symbols indicates degree of reliability. cross section line EX PL ANATI ON OF MAP SYMBOLS in cross section, inferred axial trace of large-scale fold plunging synform plunging antiform in cross section, interpreted fold form lines of non-cylindrical asymmetric folds A A' synform antiform LI NEAR FEAT U RES strike and dip of axial surface of F 3 fold strike and dip of axial surface of F 4 fold strike and dip of vertical biotite foliation in granitoid strike and dip of inclined bedding in Triassic sedimentary rocks strike and dip of inclined compositional layering strike and dip of inclined regional foliation (Srs) strike and dip of inclined regional C or C' foliation strike and dip of vertical regional C or C' foliation strike and dip of inclined fracture surface strike and dip of vertical fracture surface strike and dip of vertical regional foliation (Srs) strike and dip of inclined bedding in Triassic sedimentary rocks strike and dip of inclined pegmatite dike PL ANAR FEATU RES 61 72 23 65 55 46 57 55 strike and dip of axial surface of F 2 fold 33 bearing and plunge of mineral stretch lineation 14 35 28 57 36 47 A T normal fault, bar and ball on the downthrown side, dashed where inferred ductile strike-slip fault, dashed where inferred in cross section, normal fault arrows indicate movement in cross section, A indicates movement away from observer, T indicates movement towards observer thrust fault contact - gradational OT HER FEAT U RES UTM GRI D AND 1987 MAGNET I C NORT H DECL I NAT I ON AT CENT ER OF S HEET 7 124 MI LS 1 26 ' 25 MI LS MN GN CONT OU R I NT ERVAL 10 FEET 0.95 0 0.95 0.475 Miles 1,000 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 500 Feet 0.95 0 0.95 0.475 Kilometers SCALE 1 : 24 000 MAP LOCATION This Geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program North Carolina Geological Survey Open File Report 2016-20 Grissom 7.5-minute Quadrangle, Open File Report 2016-20 whole-rock geochemical sample location Samples UM-3-1 thru UM-3-13 collected along same transect. Not all points are indicated on map due to small sampling area. U M- 3 - 1 Moye, R. J., Jr., 1981, The Bayleaf mafic-ultramafic belt, Wake and Granville counties, North Carolina, Unpublished M.S. thesis, North Carolina State University, Raleigh, NC, 115 p. N.C. North Carolina Department of Environmental Quality Energy Group Jenny Kelvington, Executive Director Kenneth B. Taylor, State Geologist no vertical exaggeration measurement in feet below ground surface Phillips and Witanachchi Blake, Grosser and Robitaille Phillips and Witanachchi INDEX TO GEOLOGIC MAPPING ADJOINING 7.5' QUADRANGLES
Transcript of North Carolina Department of Environmental Quality North ... Mineral and Land...Geology by David E....
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7075
6177
50
6481
65
69
8
73
4668
CZfa
PPccg
Qal
Qal
Qal
Qal
Qal
Qal
Qal
CZmcgCZfs
CZfsCZbp
Trcs/c
CZct
CZfu
CZmcg
CZmg
CZmg CZmcg
CZflg
CZflg
CZmcg
Jd
Jd
Jd
Jd
Jd
Jd
Jd
Jd
Jd
Jd
Jd
p
p
p
p
p
p
p
p
p
p
CZrgn
CZhg
CZmgs
CZbg
CZrgn
CZfu
CZfu
CZfa
CZfu
CZfu
CZfu
CZfaCZfu
CZfu
CZfa
CZfs
CZhg
Qal
Qal
QalQal
Qal
Qal
Qal
Qal
Qal
Qal
Qal
CpuCZfua
Trsb
CZrgn
CZfa
CZhgCZmcg
CZfa
CZfu
CZhg
CZfu
CZflg CZrgn
CZflg
CZfs
CZfaCZfu
CZfu
CZfa
CZmcg
p
CZfs
CZfs
DUCTILE
STRIK
E-SLIP
FAULT
CZfa
CZfu
Trcc CZmcgCZfu
CZfs
CZbgCZmcg
CZflg
Trsb
Trcc
Trcc
CZgc
CZcwq
CZrl
CZrl
PzZggCZfutCZfut
CZfa
CZfuCZfa
CZfu
CZfu CZfu
CZhg
CZmcg
CZfu
CZfut
CZfu
CZfu
CZfu
CZfu
CZfa
CZfuCZfu
CZfuCZfu
CZfaCZfu CZmcg
CZfu
CZfqz
25
7080
558
CZfuCZmca
CZmca
Jd
Jd
Jd
CZfaCZfa
A'A
Trcs/si2
Qal
Qal
JdCZrgn
CZfs
Trcs/cTrcc
Qal
Trcs/si2
Trcs/si2
Trcs/si2
Trcs/si2
CZrgnFISHING CREEK FAULT
DUCTI
LE STR
IKE-SL
IP FAUL
T
DUCTILE
THRUST
FAULT
DUCTI
LE THR
UST F
AULT
JONESB
ORO F
AULT
JONESBOR
O FAULT
CZfu
PPccg
7947 4337
66
8046
62
7683
6865
CZfs
CZfs
CZfs
CZfs
U M-3-13
U M-3-1GS -39
GS -46
GS -56
CZhg
36 00' 00"
36 07' 30"78 37' 30"
GEOL OGIC MAP OF T HE GRIS S OM 7.5-MINU T E QU ADRANGL E,GRANVIL L E, FRANKL IN, AND WAKE COU NT IES , NORT H CAROL INAGeology by David E. Blake, Cindy M. Phillips, Benjamin D. Grosser, Kenneth R. Robitaille and Channa Witanachchi.
2016
Also incorporating previous mapping by Blake (1986) and Horton and others (1992).Digital representation by Michael A. Medina and Cindy M. Phillips
78 30' 00"36 07' 30"
78 37' 30"36 00' 00"
78 30' 00"
Schmidt net equal-area plot ofcontoured poles to regional foliation (n = 909)
Schmidt net equal-area plot ofcontoured poles to shear foliation (n = 103)
Schmidt net equal-area plot of contouredmineral, elongation, and stretch lineations(n = 65)
Unidirectional Rose Diagram of Joints N = 61
Base topographic map is digital raster graphic image of the Grissom 7.5-minute USGS quadrangle (1987).Geology compiled from Blake (1986), Horton et al. (1992), Robitalle (2004), and data collected by NCGS staff in 2001-2002.Partially supported by the USGS National Cooperative Mapping Program EDMAP and STATEMAP components.Mapping and research of Robitalle (2004) supported by EDMAP. Mapping by NCGS staff partially supported bySTATEMAP grants 01HQAG0061 (2001) and 02HQAG0043 (2002).
Disclaimer:This Open-File report is preliminary and has been reviewed for conformity with the North Carolina Geological Survey editorialstandards or with the North American Stratigraphic Code. Further revisions or corrections to this map may occur.
NORTH CAROLINA
CZfa
CZhg
PPccg
Trcs/c
Trcc
Trcs/si2
CZfu
CZfut
CZfua
CZfqz
Cpu
PzZgg
Qa l - Qua terna ry a lluvium : Unconsolidated, poorly-sorted and poorly stratified, tan to light gray deposits of gravel,sand, silt, and clay. Similar to stratified terraces along streams.
Cpu - Coa sta l Pla in sedim ents, undifferentia ted: Unconsolidated, fine to coarse-grained, tan to light gray arkosicsands and clayey sands with occasional gravel.
T rcc - conglom era te: Reddish-brown to dark brown, irregularly bedded, poorly sorted, cobble to boulder conglomerate.Muscovite is rare to absent in the very coarse-grained to gravelly matrix. An arbitrary cut-off of greater than 50 percentconglomerate distinguishes this unit from the Trcs/c facies. Clasts are chiefly miscellaneous felsic and intermediatemetavolcanic rocks, quartz, epidote, bluish- gray quartz crystal tuff, muscovite schist, and rare meta-granitic material. T rcs/c - sa ndstone with interbedded conglom era te: Reddish-brown to dark brown, irregularly bedded, poorly sorted,coarse-grained to pebbly, muddy lithic sandstones with interbedded pebble to cobble conglomerate. Muscovite is rare toabsent in the matrix. Well-defined conglomerate beds distinguish this unit from conglomerate basal lags of Trcs. An arbitrarycut-off of less than 50 percent conglomerate distinguishes this unit from the Trcc conglomerate facies. Conglomerate bedsare channel-shaped and scour into the underlying sandstone beds. Unit grades eastward into Trcc.T rcs/si2 - sa ndstone w/ interbedded siltstone: Cyclical depositional sequences of whitish-yellow to grayish-pink to pale red,coarse- to very coarse-grained, trough cross-bedded lithic arkose that fines upward through yellow to reddish-brown, medium-to fine-grained sandstone, to reddish-brown, burrowed and rooted siltstone. Bioturbation is usually surrounded by greenish-blue to gray reduction halos. Coarse-grained portions contain abundant muscovite, and basal gravel lags consist of clasts ofquartz, bluish-gray quartz crystal tuff, and mudstone rip-ups. T rsb - silicified breccia : Light gray to white, silicified rock that has been multiply brecciated and annealed. Contains angularclasts of probable pre-Triassic rock along the Jonesboro fault.
Jd - dia ba se dikes: Steeply dipping to vertical dikes of gray to bluish-black, fine- to medium-grained, locally porphyriticplagioclase diabase, that may be olivine-bearing. Solid lines where observed; dashed lines where inferred from correlationand aeromagnetic data.
PPccg – Gra nite of the Ceda r Creek pluton: Pink-white, medium to coarse-grained, unfoliated to moderately foliated andlineated biotite granite, with local pegmatite.
p - pegm a tite: Gray-white to pink-white, very coarse grained, microcline, plagioclase, quartz, muscovite, biotite pegmatiteof the Rolesville granite. Some outcrops exhibit a graphic texture.
PzZ gg - gneissic biotite gra nitoid (Pa leozoic?): Foliated biotite granitoid and granitoid orthogneiss interlayered withRaleigh gneiss.
CZ gc - Gibbs Creek pluton: Light green to gray-green, fine- to medium-grained, leucocratic (CI less than 20) biotite +-hornblende metagranodiorite. Locally contains planar zones of dark green to gray-green, fine-grained, well foliated andlineated, chlorite phyllite having a phyllonitic fabric.
CZ ct - Ca rolina terra ne m eta gra nitoid: Orange-tan to pinkish tan, fine- to medium-grained, highly fractured, leucocratic(CI generally less than 5), biotite-bearing metatrondjhemite to metagranodiorite. Locally, biotite can increase in abundance andor be replaced by chlorite. Gray to bluish gray quartz phenocrysts are conspicuous, and the metagranitoid is locally porphyritic.Zones of silicification and pyritization are present.
CZ bp - Bea verda m suite: Mixed assemblage of biotite- and hornblende-biotite metadiorite; hornblende metagabbro; andmetapyroxenite.
CZ fs - Fa lls L a ke schist: Variably gray colored, mesocratic, medium- to coarse-grained, biotite-white mica-oligoclase-quartzschist locally having garnet, staurolite, kyanite, and chlorite porphyroblasts. Contains pods of gabbro, amphibolite, and undividedultramafic rocks.CZ fu - ultra m a fic rocks (undivided): Variably altered ultramafic rocks including metapyroxenite, actinolite-chlorite schist,and talc schist.
CZ fa - a m phibolite: Dark gray, fine- to medium-grained, and well foliated amphibolite.
CZ hg - hornblende gneiss: Dark gray to black, medium grained, poorly to moderately foliated hornblende-plagioclase gneissand amphibolite. May contain biotite or epidote. Where biotite content is high may be somewhat schistose.CZ fut - ta lc schist: White to gray talc-tremolite schist, talc-chlorite schist, and soapstone. Rhombohedral cavities suggestformer presence of a carbonate mineral (ankerite?). CZ m g - m eta ga bbro: Light green to blue green, fine- to medium-grained, massive metagabbro containing relict plagioclaseand hornblende, and metamorphic actinolite, epidote, and opaque minerals.CZ fqz - qua rtzite: White, granular, and well foliated quartzite.
CZ fua - a ctinolite rock a nd a ctinolite-chlorite schist: dark green, schistose to almost massive, splintery rock composed ofactinolite and varied amounts of chlorite; minor amounts of talc and magnetite octrahedra are common.
Description of Ma p U nitsS urficia l U nits
Pliocen
e (?)Q
uatern
ary
Newa rk S upergroup, Cha tha m Group
Late T
riassic
Intrusive Rocks
Jurass
icPen
nsylvan
ianNeo
-Protero
zic to
Late P
aleozoic
Meta m orphic RocksCAROL INA T ERRANE
FAL L S L AKE T ERRANE
CRABT REE T ERRANE
Neo-Pro
terozoic
to Cam
brian
Trsb
CZgc
CZct
CZbp
CZfs
CZmgCZmg
CZbg
CZmgs
CZcwq
CZ m cg - Middle Creek gneiss: Fine- to coarse-grained, gneissic to schistose, locally lineated, mesocratic (CI less than 30),biotite quartz dioritic to granodioritic gneiss. Interlayered with pink-gray to orange-tan, fine- to medium-grained, locallylineated, leucocratic (CI less than 10), white mica biotite granitoid gneiss, and fine- to medium-grained amphibolitic gneiss.Also occurs as tectonic windows within Falls Lake terrane.
CZ bg - biotite ba nded gneiss: White, gray, and black, compositional layered and well foliated, biotite-quartz-plagioclasegneiss.CZ m gs - m ixed gneiss a nd schist: Complex assemblage of highly intercalated gneissic and schistose rocks. Includesquartzofeldspathic gneiss, compositionally layered gneiss, quartz ribbon gneiss, amphibolite, hornblende gneiss, hornblendite,banded biotite gneiss, muscovite schist, muscovite-garnet gneiss, biotite-muscovite-garnet schist, talc schist, and quartzite.CZ cwq - White m ica -rich a nd qua rtz-rich schist: gold-gray to silver-gray, very fine- to fine-grained, moderately wellfoliated quartz-biotite and/or chlorite-white mica schist containing sparse to abundant garnet interlayered with silver-white,fine- to medium grained, moderately foliated white mica-plagioclase-quartz schist.
CZmcg
CZrl
CZhg
CZ flg - Fa lls leucogneiss: Leucocratic (CI less than 5) pink-gray to orange-tan, medium-grained, weakly to moderatelyfoliated and strongly lineated, biotite magnetite granitic gneiss.CZ rgn - Ra leigh gneiss: Mixed unit consisting mainly of fine- to coarse-grained, well foliated, compositionally banded,and locally lineated biotite granitoid gneiss, and lesser amounts of biotite + hornblende gneiss, biotite schist, white micaschist, and amphibolite.CZ hg - hornblende gneiss: Dark gray to black, medium grained, poorly to moderately foliated hornblende-plagioclase gneissand amphibolite. May contain biotite or epidote. Where biotite content is high may be somewhat schistose.CZ rl - fine-gra ined leucocra tic gneiss: Very light gray, fine-grained, leucocratic epidote-plagioclase-quartz gneiss, locallycontaining darker, hornblende-bearing interlayers.
RAL EIGH T ERRANECZflg
CZrgn
Qal
Jd
p
CZmca CZ m ca - Middle Creek gneiss, m a fic fa cies: Dark grayish-black to dark green, fine- to medium-grained, foliated andlineated, layered, epidote-bearing hornblende gneiss to aphibolite. Locally contains opaque mineral-rich metapyroxenite.
Blake, D.E., 1986, The geology of the Grissom area, Franklin, Granville, and Wake Counties, North Carolina: A structural and metamorphic analyses [M.S. thesis]: Raleigh, North Carolina State University, 300 p.Horton, J.W., Jr., Blake, D.E., Wylie, A.S., Jr., and Stoddard, E.F., 1992, Geologic map of the Falls Lake - Wake Forest area, north-central North Carolina: U.S. Geological Survey Open File Report 92-269, scale 1:24,000, 9 p.
REFERENCES
Robitaille, K. R., 2004, Geology and terrane relationships of the Tar River area, Franklin and Granville Counties, North Carolina, Unpublished M.S. Thesis, Wilmington, University of North Carolina at Wilmington, 167p.
bearing and plungeof slickenlinebearing and plungeof mineral lineationbearing and plunge ofminor fold hinge (F2)
bearing and plunge ofminor fold hinge (F3)bearing and plunge ofminor fold hinge (F4)
contact - location inferred
contact - location concealed
CONTACT SLithologic contacts - Distribution and concentration of structural symbols indicates degree of reliability.
cross section line
EX PL ANAT ION OF MAP S Y MBOL S
in cross section, inferred axialtrace of large-scale fold
plunging synform
plunging antiform
in cross section, interpretedfold form lines of non-cylindricalasymmetric folds
A A'synform
antiform
L INEAR FEAT U RES
strike and dip of axialsurface of F3 foldstrike and dip of axialsurface of F4 fold
strike and dip of verticalbiotite foliation in granitoid
strike and dip of inclined beddingin Triassic sedimentary rocks
strike and dip of inclinedcompositional layeringstrike and dip of inclinedregional foliation (Srs)
strike and dip of inclinedregional C or C' foliationstrike and dip of verticalregional C or C' foliation
strike and dip of inclinedfracture surfacestrike and dip of verticalfracture surface
strike and dip of verticalregional foliation (Srs)strike and dip of inclined beddingin Triassic sedimentary rocks
strike and dip of inclinedpegmatite dike
PL ANAR FEAT U RES
61
72
23 65
55 46
57
55 strike and dip of axialsurface of F2 fold33
bearing and plunge ofmineral stretch lineation
14
35
28
57
36
47
A T
normal fault, bar and ballon the downthrown side,dashed where inferredductile strike-slip fault,dashed where inferredin cross section,normal faultarrows indicatemovement
in cross section,A indicates movementaway from observer,T indicates movementtowards observerthrust fault
contact - gradational
OT HER FEAT U RES
U T M GRID AND 1987 MAGNET IC NORT HDECL INAT ION AT CENT ER OF S HEET
7124 MIL S 1 26'25 MIL S
MNGN
CONTOU R INT ERVAL 10 FEET
0.95 0 0.950.475Miles
1,000 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000500Feet
0.95 0 0.950.475Kilometers
S CAL E 1:24 000
MAP LOCATION
This Geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program North Carolina Geological SurveyOpen File Report 2016-20
Grissom 7.5-minute Quadrangle, Open File Report 2016-20
whole-rock geochemical sample location Samples UM-3-1 thru UM-3-13 collected along same transect. Not all points are indicated on map due to small sampling area.U M-3-1
Moye, R. J., Jr., 1981, The Bayleaf mafic-ultramafic belt, Wake and Granville counties, North Carolina, Unpublished M.S. thesis, North Carolina State University, Raleigh, NC, 115 p.
N.C.
North Carolina Department of Environmental QualityEnergy GroupJenny Kelvington, Executive DirectorKenneth B. Taylor, State Geologist
no vertical exaggeration measurement in feet below ground surface
Phillips andWitanachchi
Blake, Grosserand Robitaille
Phillips andWitanachchi
INDEX TO GEOLOGIC MAPPING
ADJOINING 7.5' QUADRANGLES
