Bedrock geologic map of the Henderson 7.5-minute quadrangle, Vance County, 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. (2013) and Cardozo and Allmendinger (2013) 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.201 2.07.021 . Equal-Area Schmidt Net Projection of Contoured Poles to Regional Metamorphic and Shear Foliations Contour Interval = 2 sigma N = 731 Equal-Area Schmidt Net Projection of Contoured Mineral Stretching Lineations Contour Interval = 2 sigma N = 163 Unidirectional Rose Diagram of Joints N = 171 Outer Circle = 9% Mean vector = 171 degrees Southwest portion mapped by Blake, February-September2001; northwest and eastern portions mapped by Blake and Stoddard, January-October 2004. MAP SHOWING LOCATION OF NUTBUSH CREEK FAULT ZONE WITH ZONE OF BRITTLE OVERPRINT Disclaimer: This map 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. Research supported by the U.S. Geological Survey, National Cooperative Geologic Mapping Program, under USGS award numbers 00HQAG0148 and 03HQAG0170. 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. This Geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program North Carolina Geological Survey Open File Report 2016-17 CZmgr'Y ■SERV ■Spnc» ViHli T, , Ciurse SiSwaKlS.wusiK MwaOrJal'CeoY rnvhf b/‘: tV' v-Sfy-ric - A Boar TonT С 9ГН / /С / Jd PPrgd PPrgf PPrgm : : PPrgj CZmgr X X X X X X; CZafg * XX CZphc CZvcg ГТТТ I, dZvgf \ CZvgr CZvtg CZvbtf s_ S \ CZdqf < 4 \ ' dz,c\ ' ^ \ ^ CZtc CZmgb ' CZmgf ' \ \ X \ ' dZmif ' 1 t t \ CZmi CZIcg CZjbg Intrusive Rocks Jurassic Jd - Diabase: Steeply dipping to vertical dikes of gray to bluish-black, fine- to medium-grained diabase, locally porphyritic with phenocrysts of plagioclase. Most common variety is olivine bearing. Solid lines where observed, and dashed where inferred from correlation and aeromagnetic data. Isolated diabase stations indicated by a red circle. Jd2 - Two-pyroxene diabase: olivine-free diabase having augite and low-calcium pigeonitic pyroxene, commonly with quartz-alkali feldspar granophyre. Typically strongly plagioclase porphyritic. Solid lines where observed, and dashed where inferred from correlation and aeromagnetic data. Isolated diabase stations indicated by a red circle. Pennsylvanian - Permian PPrgd - Granitoid facies d: Fine to coarse-grained, but primarily medium-grained equigranular to moderately porphyritic (very rarely megacrystic), rarely foliated, pink or salmon and white biotite +/- muscovite monzogranite. Commonly has an almost idiomorphic fabric with well-formed alkali feldspar and plagioclase grains. Cl = 5 - 12. Contains common biotite schlieren and local biotite crystal clots. Pegmatite dikes and pods are extremely common; locally, isolated xenocrysts of alkali feldspar 1 - 4 cm in length also occur. Unit also contains relatively common xenoliths of Raleigh terrane country rocks, especially in Ingleside and Louisburg quadrangles. Less commonly contains autoliths of fine granodiorite or tonalite and may display igneous layering between biotite-rich and biotite-poor phases. Weathered surfaces are commonly nubbly, friable and/or cavernous. Rolesville main phase of Speer (1994). PPrgf - Foliated granite of the Rolesville batholith: Gray-white to pink-white, medium-grained, locally weakly porphyritic, moderate- to well-foliated, leucocratic (Cl less than 15) biotite granite and pink-white, medium- to -coarse-grained, unfoliated to weakly foliated granite, leucogranite, and granitic to leucogranitic gneiss. Locally pegmatitic. Leucocratic varieties locally contain muscovite or garnet. PPrgm - Mylonitic granite of the Rolesville batholith: fine, medium, or coarse-grained, locally porphyritic, white to pink biotite granite and muscovite-biotite leucogranite showing variably developed mylonitic fabric. Commonly gneissic and/or intruded by pegmatite dikes. Winged K-feldspar porphyroclasts and asymmetric folds show evidence of dextral shear. Subhorizontal lineation is common. PPrgj - Granitoid facies j of the Rolesville batholith: Heterogeneous granitoid unit consisting of streaky, gneissic, or layered biotite granitoid and biotite granitoid gneiss. Includes granite, leucogranite, and granodiorite and their gneissic counterparts. Generally medium grained but ranges from fine to coarse. Locally has alkali feldspar xenocrysts up to 3 cm. Locally exhibits strong compositional banding, elsewhere vague phase layering, boudinage of darker phases, biotite schlieren, or xenoliths of biotite gneiss. Additionally may contain feldspar or biotite foliation. Planar fabric elements may be contorted and possibly transposed. Pegmatite and aplite dikes are abundant and locally deformed. Metamorphic Rocks Late Proterozoic -Cambrian Carolina terrane CZmgr - Metagranite/metatrondhjemite: Light gray, pink or tan colored, fine-grained granitic and/or trondhjemitic suite of dikes or enclaves in contact with metatonalite and metagranodiorite of the Vance County pluton. Generally displays a leucocratic (Cl less than 5) color index with minor to accessory biotite plates and a relict phaneritic to crystalloblastic texture/microstructure. Outcrops may be highly fractured, forming resistant hillside cobble and boulder fields. 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, 1-2mm in size occur in a groundmass of nearly all potassium feldspar with minor quartzs. Present in the adjacent Oxford Quadrangle. CZphc - Chlorite phyllonite and mylonite: Light greenish-gray to dark green, foliated and lineated phyllitic rocks derived primarily from recrystallized felsic, intermediate, and mafic intrusive rocks. Includes chlorite and sericite phyllonite and mylonite that form in distinctive relict compositional layers. Iron and manganese oxide commonly coats fractured and foliated surfaces. Flattened and rotated polycrystalline aggregates of plagioclase and quartz common as porphyroclastic minerals. Quartz, feldspar, chlorite, and white mica contribute to a slickenline lineation, CZvcg - Granitoid of the Vance County pluton (?): Gray-white to green-white, coarse-grained, unfoliated to foliated, mesocratic (Cl less than 40) biotite hornblende metagranodiorite containing conspicuous relict blue quartz phenocrysts. CZvgf - Foliated felsic tonalite/trondhjemite, granodiorite, and granite of the Vance County pluton: Strain partitioned protomylonitic to ultramylonitic gneiss, and locally phyllonitic equivalents of CZvgr. Thin mm- to cm-scale gneissic layering defined by polycrystalline aggregates of feldspar and quartz and fine- to medium-grained domains of white mica and locally biotite. Felsic shape rods combine with mica aggregate films to define a mineral stretch lineation in all high strain varieties. CZvgr - Tonalite/trondhjemite, granodiorite, and granite of the Vance County pluton: White or tan colored, medium- to coarse¬ grained felsic and more minor intermediate metagranitoid. Generally leucocratic (Cl less than 5) due to minor or accessory amounts of biotite, more common gray white mica, and relict phenocrysts of quartz and plagioclase. Displays a distinctive granular saprock to saprolite weathering profile of the feldspar and quartz in less strained varieties. Concentrations of gray-colored white mica and polycrystalline quartz and feldspar domains define mm- to cm-scale, high strain zones that crosscut relict phaneritic texture. Felsic shape rods combine with mica aggregate films to define a mineral stretch lineation in all high strain varieties. CZvtg - Tonalite and granodiorite of the Vance County pluton: Gray to tan colored on weathered outcrops, and white to pinkish- white on fresh exposures. Commonly, medium- to coarse-grained and granular saprolite and saprock exposures display a salt-and- pepper appearance. Phenocrysts of biotite plates ± mm-scale prismatic hornblende are generally conspicuous, as are rounded to tabular, saussaritized and sericitized pale green plagioclase and gray to distinctly cobalt blue quartz phenocrysts. Includes elongate to rounded enclaves of fine-grained metagabbro and metabasalt. Locally crosscut by fine-grained metagranite or metatrondhjemite dikes. Concentrations of biotite, gray-colored white mica, and polycrystalline quartz and feldspar domains define mm- to cm-scale, high strain zones that crosscut relict phaneritic texture. Felsic shape rods combine with mica aggregate films to define a mineral stretch lineation in all high strain varieties. CZvbtf - Foliated to mylonitic metamorphosed biotite tonalite and granodiorite of the intermediate Vance County pluton: Dark to intermediate gray-blue, mesocratic (Cl = 25-50), and medium- to coarse-grained metatonalite and minor metagranodiorite. Locally cut by mm- to meter-scale felsic metamonzonite, metagranodiorite, and metatrondhjemite dikes. Located within the Nutbush Creek fault zone in the Henderson Quadrangle, this unit is the strongly deformed equivalent of CZvbt from the Townsville Quadrangle to the north. CZdqf - foliated meta-quartz diorite: 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. Present in the adjacent Oxford Quadrangle. CZtcf - Foliated Tabbs Creek meta-intrusive suite: Variably green colored, fine- to medium-grained phyllonite, protomylonite, and mylonite formed from felsic, intermediate, and mafic metaigneous rocks of the Tabbs Creek suite. Chlorite and white mica films define a phyllitic to fine spaced gneissic foliation and aggregate mineral stretch lineation. Degree of dynamic recrystallization varies, with polycrystalline quartz and feldspar displaying a gradational range from relict igneous to porphyroclastic S-C composite fabric. CZtc - Tabbs Creek meta-intrusive suite: Variably green-gray to gray-white colored, fine- to medium-grained, biotite metatonalite- metatrondhjemite, metagranodiorite, and locally metagranite. Biotite concentrations vary and produce outcops that range in color index from leucocratic to mesocratic. Biotite in particular, and hand samples in general, are commonly chloritized and display fine- scale dynamic recrystallization, which can mask the relict phaneritic texture, especially in easternmost exposures adjacent to the Nutbush Creek fault zone. Plagioclase commonly displays saussaurite and sericite alteration, and large quartz phenocyrts are generally lacking. Greenstone and metagabbro locally occur as enclaves, and minor fine-grained leucocratic dikes crosscut more medium-grained metagranitoid. CZmgb- Metagabbro: Dark gray-green to green-black, melanocratic, and fine- to medium-grained, with localized coarse-grained varieties. Commonly displays a relict gabbroic texture with chlorite/hornblende and local magnetite replacing pyroxene as uralite. Saussuritization of plagioclase is common. Generally unfoliated, and variably fractured. May display a "boxwork" fracture-fill of quartz and epidote. Commonly occur as lobate bodies injected by younger metagranitoid dikes. High strain varieties recrystallize to chlorite, white mica, and plagioclase phyllonite and mylonite. CZmgf - Foliated biotite metagranitoid: Gray colored, fine- to medium-grained, and generally leucocratic (Cl less than 10) color index that is defined by aligned biotite plates. Quartz-feldspar cystalloblastic matrix displays distinct shape foliation that is oriented parallel to the biotite plates. Crosscut by biotite-poor and biotite-free metagranitoid dikes. Forms a foliated enclave in an unfoliated portion of the metatonalite of the Vance County pluton. CZmif - Foliated mixed suite of meta-intrusives: Variably green colored, fine- to medium-grained phyllonite, protomylonite, and mylonite formed from felsic, intermediate, and mafic metaigneous rocks of the mixed meta-intrusive suite within the Nutbush Creek fault zone. Chlorite and white mica films define a phyllitic to fine spaced gneissic foliation and aggregate mineral stretch lineation. Degree of dynamic recrystallization varies, with polycrystalline quartz, feldspar, and phyllosilicates displaying a gradational range from relict igneous to porphyroclastic S-C foliation, shear bands, and mineral stretch lineation as composite fabric elements. CZmi - Mixed suite of meta-intrusives: Variably colored and grained sized exposures depending upon the presence of mafic, intermediate, or felsic metaplutonic rocks. Generally dark green-black, fine- to medium-grained metagabbro is cut by blue-gray to green-black, fine- to medium-grained metadiorite. Both rock types are cut by dikes and larger bodies of fine- to medium-grained leucocratic metatrondhjemite/metagranite having variable biotite content. Mafic and intermediate varieties display saussurite and sericite formation, and local chloritization. Crabtree terrane CZrcg - Ruin Creek gneiss: Variably tan-orange to gray-orange fine to medium-grained, well foliated and lineated porphyroclastic K- feldspar granitic gneiss. White mica and recrystallized K-feldspar define the shear foliation and stretch lineation. CZfgf - Foliated felsic gneiss: Dark to light pink-red-orange, fine- to coarse-grained leucocratic (Cl less than 2) felsic mylonitic to ultamylonitic gneiss. Variably foliated and lineated, and locally contains relict red-orange K-feldspar porphyroclasts and pegmatitic K- feldspar and quartz boudins. Outcrops are reminiscent of the Ruin Creek gneiss and Falls leucogneiss. CZIcg - Little Creek Gneiss: Pink-gray to orange-tan, fine- to medium-grained, well foliated to lineated, leucocratic (Cl less than 10) white mica ± biotite granitic gneiss. Locally is magnetite-bearing. CZjbg - Joes Branch Gneiss: Bluish-gray to tannish gray, fine- to medium-grained, well foliated and locally compositionally layered or schistose, mesocratic (Cl less than 35) biotite dioritic to granodioritic gneiss. Locally contains green-black, fine- to medium-grained crystalloblastic amphibolite and mm-scale layered amphibolitic gneiss. Alignment of hornblende defines a subhorizontal stretch lineation. Raleigh terrane SCALE 1:24 000 Base topographic map is digital raster graphic image of the Henderson 7.5-minute USGS quadrangle (1970, revised 1982). CONTOUR INTERVAL 10 FEET 0.5 124 MILS 1J 3 Г 27 MILS 1,000 500 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 III 1 I И 1 — I I I Feet 1 Miles 0.5 1 i Kilometers UTM GRID AND 1982 MAGNETIC NORTH DECLINATION AT CENTER OF SHEET CONTOUR INTERVAL - 10 FEET NORTH CAROLINA MAP LOCATION CRABTREE RALEIGH TERRANE TERRANE CAROLINA TERRANE ROLESVILLE BATHOLITH A 500' — , s ' . s s ' "T\\'Aw\\\\\wv> -1000'- s S s . s s s S s , S s s / \ s ' S s s cz¥ s ' S s s " V " \ s s s , s s \ s s s \ s V -2000' - \ s s S \ S S \ S ' S \ V S , s s \ \ S s \ S s \ \ s V . S S s S S V S S , v/ -3000' — ^ 1 5 ^ — Crooked Run NC 39 RUIN NUTBUSH CREEK CREEK FAULT FAULT 185 US 158 CZvtg CZmgrN CZvtg CZmi CZvbtf s S S 7 CZIcg S S s k S CZmif s S s v s J \ ' , S 1 . s s , S 'у/ Q, s s v s ' s, s N S , S '70 PPrgm 500' PPrgf — 0' — -1000' — -2000' -3000' cross sections scale - 1 :24,000 no vertical exaggeration RUIN Red NUTBUSH CZflg CZrgn CZflg -Falls leucogneiss: Pinkish-gray to orange-tan, fine to medium-grained, weakly to moderately foliated, strongly lineated, leucocratic (Cl less than 5) biotite-magnetite granitic gneiss. Discordant U-Pb upper intercept age of 550.8 +/- 4.9 Ma (Caslin, 2001) interpreted as dating crystallization of plutonic protolith. CZrgn -Raleigh Gneiss: Mixed units of mainly fine- to coarse-grained, well foliated and compositionally layered, locally lineated mesocratic to leucocratic biotite gneiss and more minor biotite schist and white mica schist. Stovall Townsville Middleburg Oxford Henderson Vicksboro Wilton Kittrell Ingleside EXPLANATION OF MAP SYMBOLS CONTACTS, FAULTS, AND OTHER FEATURES location known - diabase location known inferred concealed diabase inferred diabase concealed ADJOINING 7.5' QUADRANGLES -X-- cross section FAULTS ь>. О CAROLINA TERRANE CRABTREE TERRANE RALEIGH TERRANE ROLESVILLE BATHOLITH Faults- Solid where location known, dashed where inferred, dotted where concealed. Dashed X lines - zones of late brittle fracture and/or faulting; characterized by vuggy quartz and local brecciation. In cross sections, for ductile strike-slip faults, X indicates movement away from the observer, О indicates movement towards the observer. For normal brittle faults, D indicates downthrown side, U indicates upthrown side. 63 strike and dip of inclined regional foliation | strike of vertical regional foliation \ 65 strike and dip of inclined regional shear foliation strike of vertical regional shear foliation strike of vertical compositional layering j- ee strike and dip of inclined foliation in enclave |- as strike and dip of quartz vein ^ 38 strike and dip of slickenside surface WHOLE ROCK CHEMISTRY OF SELECTED SAMPLES OXIDES IH WEIGHT PERCENT_ TRACE ELEMENTS IN PPM |AU IN PPB) map no. sample rock typo map unit Si02 Ti02 AI203 Fe203 MnO MgO CaO Na20 K20 P205 Cr203 L.O.I. Total Ag As Au* b Ba Bg bi Cd Co Co Cs Cu Up fcr tu Ua Ud lio Hf Hg Ho In La Lu Mo Nb Nd Ni Pb Pr Rb Sm Sn Sr Та lb Th II Tm и V W Y Yb Zn Zr 1 HN04-4956 biotite gneiss CZjbg 62 72 0.93 15.61 6.22 0.13 1.79 4.77 4.35 1 50 0.25 <0.01 1.00 99.27 0.03 <001 1 378 4 ы.ь 10.4 22 34 6.6/ 397 1.88 1/ 7.53 7 1.35 236 0.55 <2 6 30.4 6 7.04 27.1 7.3 2 428.4 <0.5 1.18 2.4 <0.5 0.56 l). /4 110 <1 36.3 3.7 55 265 2 H N04-5024 metagabbro CZmgb 46 93 140 16 07 11 72 0 18 7 18 10 07 2 58 0 52 0 16 002 2 00 98 83 0 03 1 9 1 70 1 159 43 1 0 5 94 3 79 2 3 1.11 17 3 79 3 08 68 0 31 4 4 11 4 125 2 36 108 2 9 1 3332 <05 0 59 1.2 <0 5 0 3 0 33 248 <1 202 2 62 94 3 H N04-51 10 metagabbro CZmgb 48 70 1.73 16 35 10 12 0 17 5 63 9 29 326 1 01 0 28 0 02 1 55 98.11 004 1 6 <1 162 9 41 35 4 0 8 75 4 99 29 1 7 19 576 4 0 99 167 0 42 <2 8 24 62 5 81 20.5 52 2 431.6 06 09 1.5 <0.5 0 44 041 236 <1 27 7 2 8 77 163 4 HN04-5129 greenstone CZtc 49 10 1.74 1660 10.05 0 17 5.26 9.01 3.59 1.11 028 0.01 1 25 98.17 004 01 <1 1902 49 8 34.5 06 77 5.72 3 36 1.89 20 6.52 4 1.15 194 049 <2 10 296 54 7 07 22.7 62 2 435.1 0.7 099 1.3 <0.5 0.5 0 39 247 <1 31.7 3.2 87 154 5 H N04- 5266 metatonalite CZvtq 67 25 0 40 16 57 2 96 0 05 1.09 358 4 80 1 85 0 12 <0 01 0 95 99 62 <001 0 1 <1 333 9 38 7 6 1 2 12 2 02 1 07 083 18 2 74 4 0 37 21 2 0 16 <2 5 16 5 8 4 41 44 32 1 470 8 <05 0 38 7.2 <0 5 0 16 1 09 46 <1 11 1 41 139 e HN04-5420 metatonalite CZvtg 67 42 0 40 16 08 2 95 0 05 0 98 3 08 4 43 2 63 0 12 <0 01 0 95 99 09 <001 03 <1 436 4 35 9 53 1 2 14 1 81 0 89 078 18 224 4 озз 21 5 0 17 <2 4 14 3 e 406 58 9 24 <1 386 6 <0 5 031 97 <0 5 0 14 1 53 44 <1 9 1 32 129 7 H N04 -5448 biotite gneiss CZjbg 6327 0.94 16 01 5.53 0.12 1.69 4 15 4 59 1 67 0.25 <001 085 99.27 005 05 >1 520 4 51 7 9.3 2 40 6 17 3 78 1.9 17 7.04 8 1.27 24 5 0 53 <2 7 30 4 6 6 93 439 68 2 347.2 <0.5 1 06 5.8 <0.5 0.54 1 42 90 2 359 3.7 70 306 8 HN04 5451 felsic gneiss CZIcg 72 90 0 34 14 62 2 28 0 03 0 67 1 90 4 34 2 18 0 07 <0 01 0 50 99 83 0 03 <0 1 <1 505 8 18 3 2 9 0 7 5 1 49 1 32 035 14 1.05 4 0 36 5 0 26 <2 4 5 3 <5 1 39 46 12 <1 207.3 <0.5 02 82 <05 0.21 1 79 35 2 108 1 6 36 118 9 HE-1 19 felsic gneiss CZflg 78 60 0 10 11 50 1.03 001 0 12 0 24 402 396 <0 01 <0 01 0.35 9993 <1 <1 <1 <10 02 0 15 004 80 4 <0 5 09 <5 10 9 6 42 071 17 8 98 0 1 7 <001 22 004 35 1 0 93 4 11 40 7 <5 1.2 103 92 5 89 3 0.7 1 62 88 <0 5 095 5 <1 548 63 167 9 DUP-HE-1 19 felsic qneiss CZflq 78 70 0.10 11 50 1 05 001 012 0 23 403 396 <001 <001 0 40 100.10 <1 <1 <1 <10 02 0 15 004 782 <0.5 0 8 <5 10 1 6 18 0 72 17 88 0 1 7 <0 01 2 21 004 34 7 0 88 4 10 40 2 <5 1.1 10 3 88 9 9 3 3 0 5 1 61 82 <0 5 0.9 <5 <1 54 1 6.3 174 to HD-1 diabase 2 Jd2 50 50 071 1520 1080 0 17 690 11 20 1.93 0 28 0 08 004 080 98 61 10 147 47 11 HD-2 diabase 2 Jd2 50 90 066 1540 11.00 0 18 7.38 10 80 1.99 0 37 007 005 0.50 99.30 16 160 46 12 HD-3B diabase 2 Jd2 51 00 095 16 50 12 00 0 16 522 10 60 240 0 54 0 11 0 03 060 100.13 19 183 59 13 HD-4 diabase 2 Jd2 50 50 085 1780 1080 0 16 4 34 10 80 2 50 0 61 0 11 0 03 080 99 30 20 195 58 14 HD-5 diabase 2 Jd2 51 90 0.79 1650 11.20 0.17 5.18 10.40 2 14 063 0.13 J .14 0.70 100.18 22 219 87 Geochemical analyses by SGS Minerals (Toronto. Canada) using method codes XRF76Z. IMS95A, and FAI303. and individual element method code ICMS12B for Та Тош Fo as Fo203 L O.l. = oercert weigh! loss on ignition Blank data cel; Indicates sample not analyzed for parameter •Aun ppb Bedrock Geologic Map of the Henderson 7.5-minute Quadrangle, Vance County, North Carolina [ so strike and dip of biotite foliation in granitoid strike of vertical biotite foliation in granitoid ^ 52 strike and dip of inclined joint and/or fracture surface j strike of vertical joint and/or fracture surface « strike and dip of compositional layering l 15 I 30 1 75 f 62 1 strike of vertical slickenside surface bearing and plunge of mineral stretch lineation bearing and plunge of slickenline bearing and plunge of minor fold hinge bearing and plunge of F3 fold hinge ® diabase station location By David E. Blake and Edward F. Stoddard © observation station location geochemical sample location Digital representation by Michael A. Medina 2016 Henderson 7.5-minute Quadrangle, Open File Report 2016-17