plate 1 - geologic map
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REFERENCES CITED
Byars, H. E., Merschat, A. J., Hatcher, R.D., Jr., and Wooden, J. L., 2008, Timing and implications for the emplacement of the Paleozoic Vale (Cat Square) charnockite andWalker Top Granite, eastern Inner Piedmont, North Carolina: Geological Society of America Abstracts with Programs, v. 40, no. 4, p. 18.
Mapes, R. W., 2002, Geochemistry and geochronology of mid-Paleozoic granitic plutonism in the southern Appalachian Piedmont terrane, North Carolina-South Carolina-Georgia [M.S. thesis]: Nashville, TN, Vanderbilt University, 150 p.
Merschat, A. J., Gatewood, M. P., Fisher, C. M., Miller, C. F., Hatcher, R. D., Jr., Wooden, J. L, and Stahr, D. W., 2005, The Newton antiform, NC: A previously unrecognized window through the allochthonous Inner Piedmont thrust stack: Geological Society of America Abstracts with Programs, v. 37, no 7., p. 20.
Merschat, A. J. and Hatcher, R. D., Jr., 2007, The Cat Square terrane: Possible Siluro-Devonian remnant ocean basin in the Inner Piedmont, southern Appalachians, USA in Hatcher, R. D., Jr., Carlson, M. P., McBride, J. H., and Martínez Catalán, J. R., eds., The 4D Framework of Continental Crust: Boulder, CO., Geological Society of America Memoir 200, p. 553-566.
35° 30 '35° 30 '
ACKNOWLEDGEMENTS
U.S. Geological Survey National Cooperative Geologic Mapping Program EDMAP ComponentGrant # 07HQPA0004 to Dr. Robert D. Hatcher, Jr.
The University of Tennessee-Knoxville
Tectonics and Structural Geology Research Group, UTK
The University of Tennessee-Knoxville Science Alliance Center of Excellence
The University of Tennessee-Knoxville Department of Earth and Planetary Sciences
North Carolina Geological Survey
EXPLANATIONQUADRANGLE INDEX
Banoak
CherryvilleLincolnton
West
Reepsville35°37' 30"
35°30’
35°37' 30"
35° 23' 30" 35° 23' 30"
35° 30 '
81° 22' 30"
81°22' 30" 81°15’
81°15’
81°45’
81°45’
Map Area
INDEX MAP
Map area enclosed by white rectangle. BCF-Brindle Creek fault. BF-Burnsville fault. Cart. Terr.-Cartoogechaye terrane. CHMFChattahoochee-Holland Mountain fault. Cow. Terr.-Cowrock terrane. DGB-Dahlonega fold belt. FF-Forbrush fault. GLF-Gossan Lead fault. GMW-Grandfather Mountain window. NW-Newton window. SRA-Smith River allochthon, a possible outlier of the Carolina superterrane or Cat Square terrane rocks. SMW-Sauratown Mountains window. PMW-Pine Mountain window. Light gray-Probably western Tugaloo terrane rocks in Alabama and Georgia. Purple-Ordovician Elkahatchee Quartz Diorite. A-Athens, GA. H-Hickory, NC. S-Statesville, NC. WS-Winston-Salem, NC. From Merschat and Hatcher (2007).
Cat
PLAIN
fault
Brevard
DGBterr.
terr
.Car
t.
Cow.
Central
sutur
e
Tugaloo
TugalooLaur
entia
nLauren
tian
platform
Carolina
Milton
terran
e
terran
e
supert
erran
ebe
lt
GMW
SRA
SMW
PMW AL
AL
AL
GA
GA
0 100kilometers
84°
84°
82°
82°
80°
80°
34°34°
33°33°
SC
SCNC
NC
KY
TN
VAVA
VAWVA
GA
86°
86°35° 35°
36°36°
37°
38°38°
37°
margin
COASTAL
Piedm
ont
RDH 2/2005
BCF
Piedmont
Inner
Piedmont
Inner
terr.
Squa
re
NW
FF
CHMF
BF
GLF
BCFBCF
H
WS
S
A
N
375 km
MN
GN
MILSMILS4
0 15'
UTM GRID AND 1970 MAGNETIC NORTHDECLINATION AT CENTER OF SHEET
6 1/2 116
01/21 1 KILOMETER
30002000100001000 4000 5000 6000 7000 FEET
01/21 1 MILESCALE: 1:24,000
Contour interval: 20 feetDATUM IS MEAN SEA LEVEL
Field Review conducted on April 9, 2008 by:Carl E. MerschatBart L. Cattanach
North Carolina Geological Survey
Mapping by Heather Elizabeth Byars, 2007-2008Supervised by Dr. Robert D. Hatcher, Jr.
Tectonics and Structural Geology Research GroupDepartment of Earth and Planetary Sciences
The University of Tennessee
Plate 1: Geologic map of the western boundary of the Newton window in portions of Banoak, Reepsville, Cherryville, and Lincolnton West 7.5-minute quadrangles, Catawba, Lincoln, and Cleveland Counties, North CarolinaHeather E. Byars, 2009, The University of Tennessee
Plate 1: Geologic map of the western boundary of the Newton window in portions of Banoak, Reepsville, Cherryville, and
Lincolnton West 7.5-minute quadrangles, Catawba, Lincoln, and Cleveland Counties, North Carolina
DESCRIPTION OF MAP UNITS
Qal/Qc
METAIGNEOUS ROCKS
Dwt
SDmgw
SDss
METASEDIMENTARY ROCKS
METASEDIMENTARY ROCKS
METAIGNEOUS ROCKS
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to C
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ian
(?)
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ian
{
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a
Mafic complex–Undifferentiated bodies of peridotite, metagabrro, amphibolite, and metadiorite. Age and provenance currently unknown.
Diabase Dike–Dark gray, fine-grained, ophitic texture, composed of olivine, clinopyroxene, plagioclase, and opaque minerals.
Amphibolite–Dark gray to black, fine- to medium-grained, plagioclase-hornblende gneiss. Felsic and garnet contents vary. Age and provenance currently unknown.
Reepsville orthogneiss [~426 Ma (U-Pb SHRIMP)]–Light to dark gray, fine- to medium-grained, garnet-biotite-quartz-plagioclase-alkali feldspar gneiss. Felsic layers range from 1 to 50 mm.
Pott Creek mylonite [~447 Ma (U-Pb SHRIMP)]–Light to dark gray, fine- to medium-grained, garnet-bearing, quartz-biotite-plagioclase-alkali feldspar gneiss. Feldspar porphyroclast sizes from 2 to 85 mm.
Sillimanite schist–Silver-blue-gray to medium gray, fine- to medium-grained porphyroblastic sillimanite-garnet-quartz-biotite-muscovite schist. Garnet size ranges from 1 to 10 mm. Layered migmatite (metasandstone) parallel to the foliation 1 cm to 1 m thick, consisting of quartz-feldspar ± garnet ± biotite ± muscovite ± sillimanite. Large quartz-muscovite pegmatites are typically located within this unit.
Metagraywacke–Light to dark gray, fine- to medium-grained porphyroblastic ± garnet muscovite-alkali feldspar-plagioclase-biotite-quartz gneiss. Subordinate amounts of garnet-quartz-biotite-muscovite schist occur locally. Contains inter-layers and boudins of mica schist, sillimanite mica schist, and calc-silicate. Calc-silicate is a gray, fine- to medium-grained, porphyroblastic epidote-clinozoisite-biotite-hornblende-quartz gneiss with trace amounts of muscovite and sillimanite.
Lower Ashe–Tallulah Falls Formation biotite gneiss and schist–Dark gray, fine- to medium-grained, inequigranular migmatitic plagioclase-biotite-quartz gneiss and muscovite-biotite schist. Contains amphibolite layers and amphibolite gneiss boudins. Gondite (g) –Tannish pink, fine- to medium-grained, equigranular rock, composed mostly of quartz with pale-pink garnets. Occurs as 0.15 to 0.6 m layers within tfl. Weathered rock is medium to dark brown or black.
Dt Toluca Granite [~378 Ma (U-Pb SHRIMP); Mapes, 2002]–Light gray, medium-grained, granoblastic, plagioclase-alkali feldspar-quartz-muscovite-biotite-garnet gneiss.
Walker Top Orthogneiss [~355 Ma (U-Pb SHRIMP); Byars et al., 2008; ~360 Ma (U-Pb SHRIMP); Mapes 2002]–Medium to dark gray, garnet-bearing, megacrys-tic quartz-biotite-plagioclase-alkali feldspar gneiss, ranging from protomylonite to mylonite. Sheared alkali feldspar megacrysts contain ubiquitous mantled (myrmekitic) rims and are aligned subparallel to the foliation. Matrix consists of fine- to medium-grained alkali feldspar, biotite, plagioclase, and quartz. Locally contains enclaves of amphibolite, migmatitic metagraywacke, and aluminous schist. Contains xenolith of charnockite at Vale [~365 Ma (U-Pb SHRIMP); Byars et al., 2008]. Charnockite is a dark, brown-green, two pyroxene-bearing, mega-crystic quartz-biotite-plagioclase-alkali feldspar gneiss with minor amounts of hornblende and garnet.
Cat Square terrane
Eastern Tugaloo terrane
Poorly sorted, unconsolidated stream sediments, and colluvial material ranging from silt to boulders. Localized areas are well stratified consisting of beds of silt/sand and pebbles. Pebbles, cobbles, and boulders are sub-rounded to rounded. Thickness ranges from 1 to 10 m.
Planar Structures
45 Strike and dip of foliation; inclined, vertical
Map Symbols
Location of electron microprobe sample
Location of sample collected for SHRIMP analysis
Linear Structures
45 Trend and plunge of mineral lineation
Contacts
Lithologic contact: solid where exactly located, long-dashed where located within 15 m, short-dashed where approximatelylocated, and dotted where inferred.
Brindle Creek fault (Neoacadian, ~350 Ma (Merschat and Hatcher, 2007):solid where exactly located, long-dashed where located within 15 m, short-dashed where approximately located, and dotted where inferred. Teeth located on hanging wall.
Location of abandoned mine or quarry
45 Trend and plunge of mesoscopic open antiform
45 Trend and plunge of mesoscopic open synform
45 Trend and plunge of mesoscopic overturned antiform
45 Trend and plunge of mesoscopic overturned synform
(NOTE: Where structural symbols are combined, the intersection marks the point of observation.)
CharnockiteXenolith
Scale 1:24,0001 1 MILE0
dam
2-5D2-5C 2-5B
2-5Amill
2-6
2-7
2-82-9
2-8
81° 22' 30"
81° 22' 30"
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ph
Cataclastic schist, phyllonite, and myloniteCataclastic schist and phyllonite, light olive gray to dark gray, medium- to fine-grained; with variable development of "fish-scale" texture formed by curved mica flakes. Major minerals are quartz 15-40 %, muscovite-sericite 45-75 %, biotite-chlorite 2-24 %, garnet, opaque minerals, and locally graphite and staurolite. Interlayered calcareous zones from a few inches to several meters thick. Mylonite, light bluish-gray; fine-grained groundmass with rounded to lenticular feldspar porphyroclasts; strongly foliated. Composition generally the same as the porphyroclastic mylonite and ultramylonite unit. Description from Lemmon and Dunn (1973b).
m
MarbleMarble, light-gray to light-bluish-gray, fine- to medium-grained; as discontinuous pods and calcareous layers within the cataclastic schist. Maximum thickness 45 meters. Major minerals are calcite-dolomite 50-55 %, muscovite-sericite 30-40 %, quartz 1-5 %, and opaque minerals. Description from Lemmon and Dunn (1973b).
am
AmphiboliteAmphibolite, black to dark-gray, medium-grained and foliated. Composed of hornblende 63 %, plagioclase (calcic oligoclase) 18 %, quartz 10 %, epidote 4 %, and opaque minerals 4 %. Generally occurs as a discontinuous, concordant body. Description from Lemmon and Dunn (1973b).
Brevard fault zone rocks/
Chauga R
iver Formation
bpm
Brevard-Poor Mountain transitional unitGarnetiferous muscovite schist, dark-gray to medium-light-gray, lustrous, medium-grained. Composed of muscovite 28 %, biotite 33 %, quartz 28 %, plagioclase (oligoclase) 7 %, microcline 1 %, garnet 2 %, and opaque minerals. Grades southeastward from Sugarloaf Mountain to a gray to light-gray, highly lustrous, medium-grained muscovite schist; composed of muscovite, quartz, and feldspar, with a decrease in garnet and a marked increase in magnetite southeastward. A discontinuous layer of coarse-grained, white crystalline marble as much as 0.5 meter thick crops out near the base of Worlds Edge. Description from Lemmon and Dunn (1973a).
gms
Tallulah Falls garnet mica schistMuscovite-biotite-garnet-kyanite (or sillimanite) schist, light- to dark-silver-gray, inequigranular to porphyroblastic. Variable mineralogy contains quartz 7-40 %, plagioclase 4-30 %, muscovite 3-46 %, biotite 0-22 %, garnet 8-16 %, and kyanite/sillimanite 4-15 %. Poikiloblastic subhedral garnet porphyroblasts up to 4 mm in diameter occur in a fine-grained matrix. Weathers to tan and purple saprolite. Probably derived from argillaceous rocks. Description from the Glenwood and Sugar Hill 7.5' quadrangles.
ltf
Lower Tallulah Falls FormationMetagraywacke-biotite gneiss, light-gray to dark-gray, medium- to fine-grained, massive- to thick-layered, well-foliated, commonly porphyroblastic. Similar to the utf in dominant mineralogy. Generally contains a larger amount of amphibolite and is commonly more migmatitic than the utf unit. Probably derived from a feldspathic sandstone. Description from the Glenwood and Sugar Hill 7.5' quadrangles.
ltf g
Lower Tallulah Falls FormationMetagraywacke-biotite gneiss, light-gray to dark-gray, medium- to fine-grained, massive- to thick-layered, well-foliated, commonly porphyroblastic. Similar to the utf in dominant mineralogy. Generally contains a larger amount of amphibolite and is commonly more migmatitic than the utf unit. Probably derived from a feldspathic sandstone. Description from the Glenwood and Sugar Hill 7.5' quadrangles.
pom
Porphyroclastic orthogneiss myloniteLight to dark gray, fine- to medium-grained, garnet-bearing, quartz-biotite-plagioclase-alkali feldspar gneiss. Feldspar porphyroclast sizes range from 2 to 85 cm. Description from the Reepsville and Lincolnton West 7.5' quadrangles.
PCo
Biotite orthogneissLight to dark gray, fine- to medium-grained, garnet-biotite-quartz- plagioclase-alkali feldspar gneiss. Felsic layers range from 1 to 50 mm. Description from the Reepsville 7.5' quadrangle.
Undivided Tallulah Falls (tf)Metagraywacke-biotite gneiss, light-gray to dark-gray, medium- to fine-grained, massive- to thick-layered, well-foliated, commonly porphyroblastic. Major minerals are quartz 26-46 %, plagioclase 28-46 % (An25-35), biotite 15-30 %, and muscovite 1-7 %. Minor constituents are epidote, microcline, chlorite, and opaque minerals. Porphyroclasts are plagioclase and microcline. Layer thickness varies from a few millimeters to several meters. Foliation is defined by quartzofeldspathic material and micas in the metagraywacke and by biotite and muscovite in the gneiss and schist. Probably derived from a feldspathic sandstone. Description from the Glenwood and Sugar Hill 7.5' quadrangles.
tf
Upper Tallulah Falls Formation (utf)and undivided Tallulah Falls (tf)
Metagraywacke-biotite gneiss, light-gray to dark-gray, medium- to fine-grained, massive- to thick-layered, well-foliated, commonly porphyroblastic. Major minerals are quartz 26-46 %, plagioclase 28-46 % (An25-35), biotite 15-30 %, and muscovite 1-7 %. Minor constituents are epidote, microcline, chlorite, and opaque minerals. Porphyroclasts are plagioclase and microcline. Layer thickness varies from a few millimeters to several meters. Foliation is defined by quartzofeldspathic material and micas in the metagraywacke and by biotite and muscovite in the gneiss and schist. Probably derived from a feldspathic sandstone. Description from the Glenwood and Sugar Hill 7.5' quadrangles.
utf tf
um
UltramaficAltered ultramafic rock, greenish-gray, medium- to fine-grained, fair to poor schistosity. Composed mainly of chlorite, amphibole, talc, carbonate, and opaque minerals. Probably derived from medium-grained olivine-pyroxene rock. Description from Butler (1972).
eam
AmphiboliteAmphibolite, black to dark-gray, medium-grained and foliated. Composed of hornblende 63 %, plagioclase (calcic oligoclase) 18 %, quartz 10 %, epidote 4 %, and opaque minerals 4 %. Generally occurs as a discontinuous, concordant body. Description from Lemmon and Dunn (1973b).
um
UltramaficAltered ultramafic rock, greenish-gray, medium- to fine-grained, fair to poor schistosity. Composed mainly of chlorite, amphibole, talc, carbonate, and opaque minerals. Probably derived from medium-grained olivine-pyroxene rock. Description from Butler (1972).
White-mica SchistYellowish-gray to bluish-gray, medium- to coarse-grained schist composed of white mica, quartz, minor biotite, and locally oligoclase. Garnet, secondary chlorite, and tourmaline are common; staurolite and kyanite are sporadic. Typically coarse-grained and quartz-rich near the Cherryville Granite. Weathered schist is grayish pink to pale red. On western side of Inner Piedmont, contains subordinate layers of fine-grained biotite gneiss, quartz-mica schist, gray micaceous quartzite, and rarely amphibolite. In part equivalent to sillimanite schist, but at lower metamorphic grade. Description by Goldsmith et al. (1988).
ms
ea
AmphiboliteDark-gray, fine- to medium-grained, thin- to thick-layered amphibolite composed mostly of plagioclase, hornblende, and smaller amounts of diopside, epidote, and quartz. Biotite and chlorite present adjacent to mica schist layers. Bodies are generally concordant. Some contain thin layers and pods of calc-silicate rock and some rare marble. Unit includes small nonlayered masses of metadiorite and metagabro.
qd
Metamorphosed Quartz DioriteDark-gray, gneissic hornblende, biotite, quartz diorite and diorite, locally garnetiferous.
u
Ultramafic RocksVariably altered ultramafic rocks, weakly to strongly foliated. Consist of serpentine, amphibole, talc, chlorite, scapolite, opaque minerals, relict pyroxene, and rare olivine in different proportions and combinations.
SDss
Sillimanite-mica schistThin- to thick-bedded sillimanite-mica schist and gneiss, variably garnetiferous, locally pyritic. Sillimanite commonly altered to sericite. Migmatitic, with local quartzofeldspathic leucosomes and subordinate lenses of biotite gneiss (metagraywacke), quartz schist, micaceous quartzite, and calc-silicate rock. Weathers to a brown- to reddish-brown or silvery blue-gray, or yellow and reddish orange.
Biotite gneiss/ metagraywackeGray to dark-gray, thin- to thick-layered, fine- to coarse-grained, garnet, biotite, quartz, feldspar gneiss, in part garnetiferous. Locally inequigranular and porphyroblastic. Insubordinate amounts of garnet, biotite schist occur locally. Migmatitic with local quartzo-feldspathic leucosomes. Contains interlayers and boudins of light gray to white, fine-grained calc-silicate. Locally contains small masses of granite. Gradational into and interlayered with white-mica schist and sillimanite-mica schist.
SDbgm
Toluca GraniteGranitic gneiss, light-gray, medium-grained, granoblastic, poorly to non- foliated. Major minerals include plagioclase (An20-30) 18-42 %, quartz 17-25 %, microcline 15-44 %, biotite 1-16 %, and muscovite 2-22 %. Accessory minerals include garnet, monazite, ilmenite, zircon, and opaque minerals. Weathers to white and tan saprolite, and contains xenoliths of biotite gneiss. Description from the Benn Knob 7.5' quadrangle.
Dtg
Tallulah Falls Formation
Hibriten granitoidDark bluish gray to black, medium-grained porphyroclastic quartz, plagioclase, biotite, gneiss. Porphyroclasts range in size form 1/4 to 1 cm, and are dominantly plagioclase. Locally, it may contain significant amounts of alkali feldspar. Amphibolite boudins are common and layering ranges from 5 cm to massive.
hg
Dwt
Walker top orthogneissBiotite granitic gneiss (granite to granodiorite in composition), light-gray, massive, weakly foliated, megacrystic. Microcline and plagioclase megacrysts are often rimmed with myrmekite. Matrix is composed of fine to medium grained quartz 14-16 %, biotite 13-22 %, plagioclase (An25-30)15-26 %, and muscovite 1-3 %. Accessory minerals include garnet, zircon, apatite, and opaques. Description from the Benn Knob 7.5' quadrangle.
Mc
Cherryville Granite (Mississippian)Light-gray to white, medium-grained, non- to weakly foliated, two mica monzogranite. Contacts are mostly concordant, but locally discordant to foliation of country rock.
Dsg
Granite of Sandy MushLight-gray, inequigranular, gneissic biotite monzogranite containing conspicuous microcline megacrysts up to 2 cm long. Probably cogenetic with the Toluca Granite. Garnet is a common accessory.
EASTERN INNER PIEDMONT
NEWTON WINDOW
Silicified Cataclasite (Jurassic and Triassic ?)Beige to tannish white zone of steeply dipping cataclasite composed of cohesive, fine- to medium-grained, brecciated quartz that has been broken and recemented multiple times. Description from Longview 7.5-minute quadrangle.
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