Geology of the Barnesville Hydrogeologic Research Site, Lamar County, Georgia
DeanaSneyd
GEORGIA DEPARTMENT OF NA1URAL RESOURCES ENVIRONMENTAL PROTECfiON DIVISION GEORGIA GEOLOOIC SURVEY Atlanta 1995
INFORMATION CIRCULAR 98
Geology of the Barnesville Hydrogeologic Research Site, Lamar County, Georgia
DeanaSneyd
GEORGIA DEPARTMENT OF NA1URAL RESOURCES Joe D. Tanner, Commissioner
ENVIRONMENTAL PROJECTION DMSION Harold F. Reheis, Director
GEORGIA GEOLOGIC SURVEY William H. McLemore, State Geologist
Atlanta 1995
INFORMATION CIRCULAR 98
ABSTRACT
Geologic mapping around the Barnesville hydrogeologic research site was conducted in conjunction with the North Georgia Hydrology Program (NGHP). Structural and lithologic data, with an emphasis on directional weaknesses and weathering characteristics, are recorded for each rock unit in the Barnesville area. The Towaliga Fault Zone, a major lithologic and structural discontinuity, traverses east to west through the study area. Four lithologic units characterize the area north of the Towaliga Fault Zone: 1) porphyroblastic biotite-quartzfeldspar gneiss; 2) quartz-muscovite schist sillimanite; 3) interlayered gondite, gneiss, amphibolite, and schist; and 4) graphite-sillimanite schist. Lithologic units that occur within the Towaliga Fault Zone include: 1) sheared and silicified biotite-quartz-feldspar gneiss garnet muscovite; 2) sheared biotite-feldspar-quartz-mus_covite schist garnet kyanite; and 3) intensely granulated cataclasite (flinty crush rock). Quartzite and garnet-quartzmuscovite schist kyanite occur within and at the southern margin of the Towaliga Fault Zone. Garnetmuscovite-biotite-quartz-feldspar gneiss with local cataclasite lenses characterizes the area south of the Towaliga Fault Zone. Metamorphic mineral assemblages observed within and south ofthe Towaliga Fault Zone indicate kyanite-grade metamorphism; whereas, mineral assemblages north of the Towaliga Fault Zone are characteristic ofsillimanite-grade metamorphism. Early, regional deformation is expressed by isoclinal folding and thrust faulting. The Towaliga Fault Zone overprints the regional deformation and is characterized by an extensive belt of heterogeneously sheared and brecciated rocks that have endured multiple episodes of ductile and brittle movement. Four joint orientations are prominent in the study area: northwest-southeast, northeastsouthwest, east-west, and north-south. The variable dominance of these features is a function of rock type and geographic location with respect to the Towaliga Fault Zone. Differential weathering occurs at contacts between units with significantly different rheologic properties (i.e., feldspathic gneiss versus quartzite). Deep weathering of less resistant units adjacent to more resistant units suggests preferential movement of ground water. Several units with differing rheologic contrast occur in the fault zone due to heterogeneous distribution of shearing and silicification; this heterogeneity increases the potential for the development of high yield wells.
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TABLE OF CONTENTS
IN1RODUCTION .......................................................................................................................................................................... 1 PREVIOUS WORK ........................................................................................................................................................................ 2 GEOLOOIC SETI'ING ................................................................................................................................................................... 2 LITHOLOGICDESCRIPI10NS ................................................................................................................................................... 2 NorthoftheTowaligaFaultZone .................................................................................................................................................... 2
Porphyroblastic biotite gneiss .................................................................................................................................................. 2 Schist ........................................................................................................................................................................................ 2 Amphibolite ............................................................................................................................................................................. 4 Migmatitic gneiss andschist ..................................................................................................................................................... 4 Gondite-Amphibolite-Schist-Gneiss ....................................................................................................................................... 4 Graphite-Sillimanite Schist ...................................................................................................................................................... 4 TowaligaFaultZone ........................................................................................................................................................................ 6 Augen Gneiss ....................................................................................................................................................................-..... 6 Schistose Gneiss ....................................................................................................................................................................... 6 SouthoftheTowaligaFaultZone .................................................................................................................................................... 6 lnterJayeredQuartziteandSchist ............................................................................................................................................. 6 GarnetiferousBiotiteGneiss .................................................................................................................................................... 7 Cataclasite ................................................................................................................................................................................ 7 S1RATIGRAPillC CORRELATION ........................................................................................................................................... 7 S1RUCfURE ................................................................................................................................................................................. 8 EarlyFoldsandFaults ...................................................................................................................................................................... 8 TowaligaFaultZone ........................................................................................................................................................................ 8 METAMORPillSM ....................................................................................................................................................................... 11 HYDROGEOLOGY ...................................................................................................................................................................... 11 CONCLUSIONS .................. .......................................................................................................................................................... 14 REFERENCES CITED ................................................................................................................................................................. 15
FIGURES
1. Location of the Barnesville hydrogeologic research site ......................................................................................................... 1 2. Drill hole location map of the Barnesville hydrogeologic research site .................................................................................. 3 3. Regional stratigraphic correlation oflithologies mapped on the Barnesville quadrangle ...................................................... 5 4. Contoured, lower hemisphere, equal-area stereoplot of248 poles to foliation outside the Towaliga Fault Zone ................ 9 5. Contoured, lower hemisphere, equal-area stereoplot of 167 poles to foliation within the TowaligaFaultZone .................. 10 6. Contoured, lower hemisphere, equal-area stereoplot of 141 poles to foliation in a one-mile radius around the Barnes-
ville hydrogeologic research site ............................................................................................................................................ 10 7. Contoured, lower hemisphere, equal-area stereoplot of330 poles to joint surfaces outside the Towaliga Fault Zone ........ 12 8. Contoured, lower hemisphere, equal-area stereoplot of175 poles to joint surfaces within the Towaliga Fault Zone .......... 12 9. Contoured, lower hemisphere, equal-area stereoplot of 153 poles to joint surfaces within a one-mile radius around
theBarnesvillehydrogeologicresearchsite ........................................................................................................................... 13
APPENDICES
1. FoliationandJointData .............................................................................................................................................................. 16
PLATES
1. Geologic map ofthe Barnesville hydrogeologic research site, Lamar County, Georgia ..................................... cover envelope 2. Jointsetmap; Barnesvillehydrogeologic research site,LamarCounty, Georgia .................................................. coverenvelope
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INTRODUCTION
Historically, hydrogeologic systems have predominantly been characterized for Coastal Plain aquifers; consequently, there has been a paucity of systematic research concerning the geologic and hydrologic controls on ground-water systems in the crystalline rocks of Georgia In 1987, the North Georgia Hydrology Program (NGHP) of the Georgia Geologic Survey (GGS) initiated a large-scale study to develop a better understanding of hydrogeologic systems in the crystalline rocks of the Piedmont and Blue Ridge physiographic provinces of Georgia. During the past eight years, three hydrogeologic research sites were established in central and northern Georgia asapartoftheNGHP(Fig.1). lnformationgatheredateachof these sites has been focused primarily on the hydrologic characterof the specific site. Currently, the study is being expanded to incorporate a more comprehensive geologic characterization of each research site and explore its relationship to the hydrogeology in the area. Ultimately, the correlation ofthe geologic data to the hydrologic data will provide a better understanding of the combination of geologic features that enhance the flow of ground water in crystalline rocks. This knowledge will reduce the risk involved in ground-water supply development and proteCtion.
The Barnesville hydrogeologic research site was developed during the summer of 1990 and consists of 1production
well and 8 monitoring wells, two of which are core holes (Fig. 2). This site was chosen as the first site for a complete and comprehensive geologic characterization and is the focus of this study. The Barnesville 7.5 minute U.S. Geological Survey quadrangle occupies nearly one-halfofLamar County, cenlml Georgia. Topographic elevations vary from greater than 1040 feet on top ofHog Mountain to less than 620 feet in the swampy flood plains ofTowaliga Creek. Streams and creeks within this quadrangle show a complex drainage pattern controlled by variable lithologic, structural and weathering characteristics of the underlying crystalline rocks (Fig. 3).
The project area comprises approximately 80% of the Barnesville quadrangle. Geologic mapping at 1:24,000 scale
includes lithologic and structural characterization of an area
within a four mile radius of the study site (Plate 1). Lithologic and structural data were gathered with an emphasis on directional weaknesses (i.e.,compositionallayering, foliation,joints, faults, shearing) and their weathering characteristics. A greater concentration of similar data were gathered within a one mile radius of the drill holes to enable a more systematic correlation with hydrogeologic data. A total of50 days were spent in field mapping, sampling, and photo-documenting specific geologic and hydrogeologic features. Because the focus of this study is to describe pertinent geologic features, the relationship of the geologic features to the hydrogeologic data will be discussed in a separate report.
Barnesville Hydrogeologic Research Site
Figure 1. Location of the Barnesville Hydrogeologic Research Site. 1
PREVIOUS WORK
North of the Towaliga Fault Zone
Crickmay (1952) and Pickering (1976) provide a summary and synthesis of the geology of the crystalline rocks of Georgia. Several regional geologic studies have included portions of the Barnesville quadrangle. Many of these studies have focused on the Pine Mountain Window and its northern terminus, the Towaliga Fault Both of these features roughly trend east to west through the centerof the quadrangle. Hooper and Hatcher (1989), Higgins and others (1988), Sears and others (1981), Atkins and Lineback (1992) and Higgins and Atkins (unpublished map) provide the most recent interpretations of this region. Grant (1967) provides a brief geologic descriptionofLamarCountywith an emphasis on the Towaliga Faultin the Barnesvillearea. Agravity surveyofLamarCounty was conducted by Favilla (1985), and Gorday (1989) assessed and summarized the hydrogeologic environment of Lamar County. Steele and others (in preparation) are investigating the hydrologic character of the Barnesville hydrogeologic research site.
GEOLOGIC SETTING
The Barnesville quadrangle is characterized by three northeasterly to easterly trending assemblages ofrocks (Plate 1). The northwestern-most assemblage ofrocks consists ofan interlayered sequence of schist, gneiss, and amphibolite; whereas the southern-most assemblage consists of schist and Grenvillianage gneiss (Higgins and others, 1988). These two assemblages ofrocks are separated by the Towaliga FaultZone. The central assemblage is characterized by an extensive belt of differentially sheared and brecciated gneisses and schists which texturally range from cataclasites to mylonites.
At least three major deformational events have been recognized within the map area (Grant, 1967). Early, tight to isoclinal, west-southwest- to west-northwest-trendingfolds are overprinted by broad, open north-northwest to north-northeast trending folds. A third deformational event, involving multiple episodes of ductile and brittle movement within the Towaliga Fault Zone, is recognized throughout the central portion of the project area. The Towaliga Fault Zone is interpreted as representing a major structural and lithologic discontinuity across the Barnesville quadrangle; therefore, lithologic descriptions are subdivided into three categories: rock units north of the Towaliga Fault Zone, rock units within the Towaliga Fault Zone, and rock units south of the Towaliga Fault Zone.
Porphyroblastic biotite gneiss Aheterogeneous mass ofinterlayeredgneiss,amphibolite, and schistoccupies most ofthe northern halfof the Barnesville quadrangle. The gneiss is texturally and mineralogically variable, ranging from: 1) porphyroblastic gneiss (most abundant), to 2) granitic gneiss, to 3) biotite schist (least abundant), all containing variable amounts of pegmatitic material. The porphyroblastic gneiss is characterized as a granular, mediumto coarse-grained, modemtely layered unit containing an equigranular biotite-quartz-feldspar "matrix" and coarser (0.5 to 4.0 em diameter) feldspar quartz porphyroblasts. Garnet is mre in the northern porphyroblastic gneiss assemblage. Locally, this unit appears exfoliated in saprolite, but generally occurs as either loose, granular saprolite that maintains its fabric if undisturbed, or as deeply weathered soil. The porphyroblastic gneiss weathers reddish orange due to moderate oxidation of biotite, and is commonly characterized by black Fe-Mn oxide staining along joints. Feldspar and biotite commonly are partially weathered to completely weathered, occurring as white clay (probably kaolinite) and vermiculite, respectively. Because of the uniformity and deeply weathered nature of this gneissic sequence, the topography is chamcterizedbynearlyflattogentlyrollinghillswherefreshoutcropand saprolite are mre. The granitic gneiss generally occurs as a medium-gmined, equigranular quartz and feldspar gneiss with disseminated flakes of fme-grained biotite. Unlike the porphyroblastic gneiss, this unit has poorly developed segregation layering and weathers to a white to grayish orange-pink saprolite. Locally, feldspathic quartz-biotite schist is interlayered with the porphyroblastic gneiss. The layers range in thickness from< 1to 3meters. This unit is fine- to medium-gmined, black and well foliated due to the alignment ofbiotite. When present in the porphyroblastic gneiss, the entire sequence appears moderately well-layered, blocky in outcrop (versus rounded) and more resistant to weathering. Pegmatitic pods and spherical masses composed ofquartz and feldspar usually occur concordant with layering in the porphyroblastic and granitic gneiss. These pods and spherical masses are highly variable in length, ranging from 1 em to >1 m, are usually fairly narrow (1 to 10 em), and locally appear boudined and/or rotated. They are roughly equigranular, massive, and weatherwhite from the decomposition offeldspar and lack offerromagnesium minerals. These units are inferred to represent metamorphic pegmatites.
LITHOLOGIC DESCRIPTIONS
In this section, each major lithologic unit is characterized in relation to mineralogy, grain size, compositional layering, and various weathering features. Because of their effects on depth ofweathering,efficiencyofgroundwaterflow, and water quality, these factors are relevant to the hydrogeologic character of the rock units. The distribution of each of these units is illustrated on Plate 1.
Schist Two different schists occur interlayered with the porphyroblastic gneiss: 1) quartz-muscovite schist, and 2) sillimanite-quartz-muscovite schist The quartz-muscovite schist is medium-grained, modemtely-well foliated and locally contains garnet, biotite, and chlorite. Thefoliation is planarand occurs as thin layers giving the schist a fissile to locally slabby appearance. The schist weathers silvery reddish-green to reddish-yellow depending on the intensity of oxidation along
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Figure 2. Drill hole location map of the Barnesville hydrogeologic research site . (Map from Barnesville U.S.G.S. 7.5 minute quadrangle, 1973.)
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prominent planes of weakness (i.e. foliation). Because of the are locally garnetiferous, possibly indicating effects of hydro-
higher muscovite and quartz content. this schist is more resis- thennal alteration and/or contact metamorphism related to the
tant to weathering than the porphyroblastic gneiss; thus it crops Hollonville Granite.
outin areas where the gneiss iscovered. The schistose units are
scattered throughout the gneiss and range in thickness from 3 to
Gondile-Amphibolile-Schist-Gneiss
30 meters. Locally, pegmatitic quartz-feldspar pods occur in
A band of interlayered gondite, amphibolite, schist. and
the schist.
gneiss (referred to inclusively as gondite) trends northeast-
The sillimanite-quartz-muscovite schist occurs as a me- southwest across the northwestern comer of the Barnesville
dium-grained, moderately-well foliated, fissile schist with lo- quadrangle. This intercalated sequence of rocks is generally
cal concentrations of graphite, garnet and feldspar. Locally, 100 to 200 meters thick (in outcrop width) and extends for
quartz veins or pods containing sillimanite and feldspar occur several kilometers northeast and southwest of the Barnesville
concordant with foliation. This unit weathers purplish to quadrangle, serving as an excellent regional marker bed in this
pinkish red and has black Fe-Mn oxide staining and pods part of the Piedmont (Higgins and Atkins, unpublished map-
developedcoplanarwith foliation andjointfaces. Similarto the ping). Gondite occurs as a texturally massive, thin (up to 1m)
quartz-muscoviteschist, the sillimanite-quartz-muscoviteschist layer that is fine- to medium-grained and equigranular consist-
is also more resistant to weathering than is the gneiss.
ing of spessartine-rich garnet and quartz muscovite. In
weathered outcrops, the gondite characteristically occurs as a
Amphibolile
fairly resistant. blocky unit The typical black color of this unit
Plagioclase-hornblende amphibolite is characterized as a is due to a high manganese content The associated schist
fine-grained, equigranular unit that is massive and resistant to comprises the bulk of this sequence of rocks and is character-
weathering. In more deeply weatheredoutcrops, this unit forms ized as a medium-grained. moderately-well foliated, fissile to
a yellowish to reddish-brown saprolite that contains a distinc- slabby, garnetiferous sillimanite-quartz-muscovite schist that
tiveboxworktexture(appears honeycombedathand-lens scale), weathers purplish-red. Numerous amphibolite and
giving the rock acharacteristic porous appearance. The amphi- porphyroblastic gneiss interlayers represent a minor portion of
bolite usually crops out as rectangular blocky masses due to this rock unit and are similar to those previously described.
extensive joint development lnterlayers ofamphibolite in the
porphyroblastic gneiss are very sparse, occurring as relatively
Grophile-SillinuJnile Schist
thin (<1m), discontinuous lenses.
The graphite-sillimanite schist occurs northwest of the
gondite-bearing unit in the extreme northwestern comer of the
Migmatitic gneiss and schist
Barnesville quadrangle. The graphite-sillimanite schist is
The porphyroblastic gneiss and associated schist have medium-grained, moderately-well foliated and is locally gar-
been migmatized to varying degrees in the northeastern comer netiferous. This unit weathers pinkish to purplish red-white,
of the Barnesville quadrangle by inlrusive effects of the has local concentrations ofFe-Mn oxide, and is usually fairly
Hollonville Granite. The Hollonville Granite occurs north of resistant to weathering. Sillimanite occurs as white, fibrous
the Barnesville quadrangle on the Orchard Hill quadrangle needles roughly 5 to 10 mm long and 0.5 to 1mm wide, with a
(Atkins and Lineback, 1992, and Higgins and Atkins, unpu~ lessprominentcleavageorientedperpendicular to the long axis.
lished mapping). The migmatized units occur as medium- Submetallic, black graphite plates, up to 0.5 to 1 mm in
grained, equigranular, moderately well-layered porphyrobastic diameter, are near-ubiquitous within the sillimanite fibers.
and granitic gneiss interlayered with biotite schist The schist Foliation is generally planar, although locally it is highly
layers, locally garnetiferous, contain high concentrations of defonned as indicated by complex interference patterns at
biotite and the gneiss/schist contacts are abrupt Biotite segre- outcrop scale. Quartz veins containing sillimanite feldspar
gations are moderately-well foliated and define ptygmatic occur concordant to foliation. Additionally. a single interlayer
folding. Locally, areas less migmitized appear similar to the of porphyroblastic gneiss was observed in the extreme north-
porphyroblastic gneiss. Migmitization is best developed in western comer of the quadrangle.
heterogeneous zones where more schistose units are interlay-
.A wide zone of resistant. intensely folded and faulted
ered with the gneiss. This association may be indicative of graphite-sillimanite schist occurs in three outcrops along topo-
preferential movement of hydrothennal fluids along planes of graphically high areas that trendparallel to the gondite-bearing
weakness. The migmitized gneiss weathers reddish-orange unit The graphite-sillimaniteschistis interlayered with biotite-
and has local black Fe-Mn oxide staining and "pod-like" muscovite-quartz schist chlorite feldspar and massive
concentrations along foliation planes. This unit is generally blocks ofporphyroblastic gneiss which appear to beinfoldedin
more resistant than its unmigmatized parent and is more com- the schist Several elongate lenses and pods of massive, very
..
monly exposed.
competent. equigranular quartz garnet granofels (gondite)
Analogous to the porphyroblastic gneiss, the migmitized occur in the schist The adjacent foliation is highly defonned,
gneiss is intercalated with biotite-sillimanite-quartz-muscovite probably accommodating strain around the more resistant
schist, and quartzo-feldspathic pegmatitic pods aligned like granofels pods. A single muscovite-quartz-feldspar pegmatite
augens or boudins along foliation. Unlike the porphyroblastic was observed. An abundance of quartz veining occurs in all
gneiss, the migmitized gneiss and associated sillimanite schist graphite-sillimanite schist outcrops and two temporally distinct
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Higgins and others (1988)
Clarkston Formation
Barrow Hill Formation
~ I
I Zebulon
Formation
VI
Pine Mountain Group
Manchester Schist
I Hollis Quartzite
Sears and others (1981)
Clark (1952) Hewett and Crickmay (1937)
? Not Available
Manchester Schist
I Hollis
Quartzite
Carolina Gneiss
Manchester Formation
I Hollis Quartzite
This Study
graphite sillimanite
Schist
Gondite
porphy
migmatized Gneiss
kyanite and garnet Schist
Quartzite
Wacoochee Complex
Sparks Schist
Woodland Gneiss
Sparks Schist
Woodland Gneiss
?"
I Woodland Gneiss
garnetiferous
biotite Gneiss
Note: Relative stratigraphic thickness is approximate.
Figure 3. Regional stratigraphic correlation of lithologies mapped on the Barnesville Quadrangle.
generations were noted. 1be ftrst occurs as small lenses concordant to foliation and probably formed as "sweat-out" veins during prograde metamorphism. 1bese veins have subsequently been deformed creating "S", "Z", and "M" type folds, and local boudins. 1besecond type ofquartz vein is temporally later and occurs as large, cross-cutting irregular masses.
Towaliga Fault Zone
Augen gneiss 1beheterogeneouseffectsofshearingarebestdisplayedin the gneiss and gneissic schist in the Towaliga Fault Zone. Sheared biotite-quartz-feldspar gneiss garnet muscovite is primarily characterized by the presence of augened feldspar ranging from 0.05- to 3-cm long and ribboned lenses of interstitial quartz. These features are highlighted by numerous thin biotite laminae which anastomose and deflect around the feldspar and quartz producing a well layered, anisotropic/ mylonitic fabric. Garnet, when present, is typically concentrated in the more biotite-rich laminae. Muscovite is locally present in variable amounts. Feldspar porphyroblasts are commonly observed aligned along foliation and probably represent a stretching lineation associated with shearing. The augen gneiss grades laterally (east and west) into zones ofmoderate to pervasive silicification that usually occur as very resistant blocky, porphyroblastic (feldspar clasts >5 to 10 mm) gneiss with abundant associated quartz veins. The resistant nature of this unit is expressed topographically by relatively steep ridges and isolated knolls. Unlike the augen gneiss, the silicified gneiss is not well layered and contains a lower volumetric abundance of mica (both biotite and muscovite). Lensoidal shaped zones of cataclasites (possibly microbreccia, although no petrographic analysis has been performed), with abrupt contacts, occur within the silicified gneiss and augen gneiss. These wnes have been previously referred to, in a general sense, as flinty crush rock (FCR) by various workers in the southeast These lenses trend northeast to southwest, roughly paralleling the orientation of the Towaliga Fault Zone, and range in size from discreet laminae within the gneiss to extensive, mappable units. 1be cataclasites are characterized as very fme-grained to microcrystalline, massive, white quartz feldspar muscovite with an associated welldeveloped shear foliation. 1be occurrence of a unit characterized by medium- to coarse-grained, rounded feldspar porphyroclasts set in a black, aphanitic matrix of rock flour (probably quartz , feldspar, and mica) was also observed interlayered with the augen gneiss. This unit texturally represents a blastomylonite and/or ultramylonite (Sibson, 1977) and indicates that this portion of the Towaliga FaultZone has undergone more intensecataclasis than the surrounding units.
Schistose gneiss A sequence of intercalated schist, schistose gneiss, and augen gneiss occurs along the east-central margin of the Barnesville quadrangle within the Towaliga Fault Zone. The schist is characterized as a medium-grained, well foliated feldspar-
quartz-muscovite schist garnet biotite chlorite kyanite. This unit weathers silvery pinkish-red to greenish-gray, is fissile to slabby, and is locally porous due to degradation of feldspar. Granulated kyanite-bearing quartz veins occur locally in the schist These veins are variable in thickness, contain scarce submetallic sheet-like hematite and have a boxwork texture formed from the decomposition of feldspar. Local pegmatitic quartz-feldspar lenses were observed, and are concordant to the dominant foliation. Effects of ductile deformation are indicated by the development of shear fabrics such as "micaftsh",quartzribbons,andbuttonschist(ListerandSnoke, 1984). Laterally, thisschistgradesinto biotite-feldspar-quartzmuscovite schist kyanite, into feldspar-quartz-muscovitebiotite schist with pegmatitic lenses, and into sheared quartzfeldspar-biotite gneiss muscovite. 1be schists and gneisses are similar mineralogically but vary texturally in that the schist is moderate to well foliated and displays numerous shear fabrics. An attempt was made to map the sheared gneissic schist separately from the sheared augen gneiss on Plate 1. However, these contacts are very imprecise due to their extremely transitional nature.
South of the Towaliga Fault Zone
Interlayered QuartzUe and Schist A narrow zone of quartzite traverses, east to west, across the entire quadrangle near the southern margin of the Towaliga Fault Zone. This unit is characterized as a medium-grained, granular, micaceous-feldspathic quartzite. Medium- to coarsegrained muscovite generally defmes a moderately-well developed foliation, with the schistose layers averaging >0.25 mm thick and the granular quartz layers averaging 0.5 to 1 mm thick. The quartz layers are commonly ribboned and coarse-grained mica fish are locally developed. Magnetite occurs in variable abundances as an accessory mineral. Garnet was observed in mica-rich layers in a few places The quartzite weathers tannish to orangish-white, is usually well jointed, flaggy to blocky (depending on muscovite content), and becomes porous and friable as the feldspar weathers and leaches away. This unit is usually very resistant to erosion and typically is expressed as a topographic ridge. Several 6 mm to 10 em thick lenses of porous, highly concentrated zones of iron oxide are located concordant and discordant to foliation and along some joint surfaces. These lenses commonly contain muscovite and quartz. 1be quartzite ranges in outcrop width, from 30 to 275 meters. Thinner portions are generally characterized by a mylonitic texture. The pinch and swell appearance in map pattern is most likely due to tectonic attenuation, although it could, in part, also represent original difference in depositional thickness. On the eastern edge of the quadrangle, the quartzite unit becomes more heterogeneous, alternating with a garnetiferous quartz-muscovite schist feldspar. These schistose interlayers vary from 1 em to 5 meters thick on outcrop scale, andup to 200 meters thickon aregional scale. 1besmaller scale micaceous interlayers weather dark('l' and are slightly less resistant than the quartzite, giving the unit a stripped look.
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Additionally, these layers act as marker "beds" within the quartzite and prove useful in delineating structures. The larger scale schistose interlayers (50 to 200 meters) are characterized as medium- to coarse-grained, well foliated, garnet-quartzmuscovite schist feldspar with local platy graphite. This unit weathers purplish-red to yellowish-orange, is preferentially oxidized along foliation, and has a black Fe-Mn oxide staining coplanar to foliation and along joint surfaces.
Two continuous units of variably sheared quartzite crop out north of the main quartzite sequence within the Towaliga Fault Zone. Locally, these limbs are mineralogically and texturally indistinguishable from the larger quartzite unit The southern-most of these two thinner units grades laterally from sheared quartzite to mylonitic quartzite and, locally cataclasite, showing a wide variation in development of tectonic flow structure. These units are very resistant to weathering, probably due to localized secondary silicification associated with shearing. They are commonly expressed as ridges but are often well exposed in creek beds. The units have been relatively unaffected by weathering andgenerallycropoutas fresh, unoxidized rock.
These two thin quartzite units enclose abody ofaluminous schist The schistis characterized as a medium- to very coarsegrained, modemtely layered kyanite-garnet-quartz-muscovite schist feldspar. Kyanite generally occurs in heterogeneously concentrated layers within the schist and probably represents zones originally rich in alumina. The kyanite is characterized as elongate, bluish-green blades and the garnet and kyanite are variable in grain size, ranging from 1 mm to 2 em, and 5 mm to 1.5 em, respectively. Shear fabrics noted in this unit include quartz ribbons, mica fish, and a stretching mineral lineation defmed by kyanite. The kyanite-garnet schist weathers purplish-red to yellowish-red and is modemtely-well exposed along Big Towaliga Creek between the two enclosing units of thin quartzite. This schist unit differs from the garnetiferous schist that is interlayered in the main quartzite sequence only by the presence ofkyanite. Because kyanite is so heterogeneously developed in the kyanite-garnet schist, the garnetiferous schist may be the same unit but without the alumina-rich zones developed to the same extent as in the kyanite-garnet schist
Gametiferous Biotite Gneiss A fairly heterogeneous sequence of granitic gneiss with pegmatitic lenses and schistose interlayers exists in the southem half of the Barnesville quadrangle. Mineralogically, this unit is very similar to the porphyroblastic gneiss north of the Towaliga Fault Zone; however, it is texturally distinct The gneiss south of the Towaliga Fault Zone is charocterized as a medium- to coarse-grained,well-layeredgarnet-biotite-quartzfeldspar gneiss muscovite pyrite. The well layered appearance of this gneiss is attributed to the thorough development of segregation banding between the leucosomes and melanosomes. Garnet and biotite occur both as disseminated grains in
1
the quartz-feldspar leucosomes and in concentrated aggregates or clots that form a lineation in the plane of foliation. The gametiferous biotite gneiss is generally more micaceous (both biotite and muscovite) than the porphyroblastic gneiss north of
the Towaliga Fault Zone. Because ofthe mica enrichment and segregation, the saprolite is well preserved compared to the saprolite observed in the porphyroblastic gneiss. Lens-shaped quartz-feldsparpegmatites within the gametiferous biotite gneiss have 0.5 to 2 em biotitic haloes, probably reflecting effects of metamorphic segregation. The gneiss weathers orangish-red to dark red with scattered Fe-Mn oxide-enriched biotite clots that probably represent remnant garnet-biotite aggregates. This unit crops out as planar slabs and blocks, but is most commonly observed as saprolitic soil.
Near the garnetiferous biotite gneiss-quartzite contact, a transitional zone occurs, grading from thinly laminated garnetiferous biotite gneiss to augened garnetiferous biotite gneiss to sheared biotite-feldspar-quartz-muscovite schist to quartzite. This transition is observed over roughly 30 meters and occurs discontinuously but persistently along the southern and northem margins of the main quartzite body.
When the garnetiferous biotite gneiss does not grade transitionallyinto a shearedschistdirectly south ofthe quartzite contact, it occurs as an intensely sheared unit that is deeply weathered. This weathering characteristic is probably a function ofthe greater susceptibilityofgneiss to weathering than the quartzite due to a greater abundance of feldspar in the gneiss. The gneiss and schist in this transition zone are very similar to that described within the Towaliga Fault Zone and may represent the same stratigraphic unit, or may have endured similar physical processes as the sheared gneissic schist and the augen gneiss.
Cataclasile Several interlayers ofcataclasite (sometimes referred to as flinty crush rock) occur within the garnetiferous biotite gneiss. These units are white, very fine-grained to microcrystalline, have a well-developed shear foliation and are locally brecciated as evidenced by open-space veins filled with coarse (<5 em long), inward -projecting quartz crystals. Locally, these veins are not completely infilled with quartz crystals and partial permeability in the vein is preserved. These brittle features were also observed in local portions of cataclasites in the TowaligaFaultZone. The interlayers ofcataclasite occur up to 3.5 km south of the Towaliga Fault Zone but were not observed north of the Towaliga Fault Zone.
STRATIGRAPHIC CORRELATION
An attempt to correlate lithologic units of the Barnesville quadrangle with the Piedmont stratigraphy is important because of the potential to indicate the amount of relative movement experienced along the TowaligaFaultZone in the Barnesville area and to correlate age and tectonic relations determined elsewhere in the region. Terminology of previous workers together with that of the present study is summarized in Figure 3 The garnetiferous biotite gneiss south of the Towaliga Fault Zone is generally believed to represent the Grenvillian basementandisreferred to as the Woodlandgneissofthe Wacoochee Complex by Bentley and Neathery (1970). Hewett and Crickmay's (1937) description of the Sparks schist correlates
7
with that of the sheared gneissic schist and the transitionally adjacent augen gneiss. Bentley and Neathery (1970) and Higgins and others (1988) included this unit in the Wacoochee Complex; however, Sears and others (1981) have included the Sparlcs Schist in the Pine Mountain Group. The thick quartzite and the two thinner units correlate with the Hollis quartzite, which is considered to stratigraphically overlie the Sparks Schist (Hewett and Crickmay, 1937). The kyanite-garnet schist and garnetiferous schist are probably equivalent to the lowermost member of the Manchester Schist as described by Clarke (1952). The Hollis quartzite and the Manchester Schist are interpreted as belonging to the Pine Mountain Group (Bentley and Neathery, 1970). The porphyroblastic gneiss north of the TowaligaFaultZone represents theZebulon Formation and the gondite and graphite-sillimanite schist belong to the Barrow Hill and Clarkston Formations, respectively (Higgins and others, 1988).
STRUCTURE
Orientation of compositional and structural anisotropies (i.e., foliation, lineations, fold axes, faults,) are ofgreat importance in controlling fracture behavior. These features will be discussed in this section. Joint openings frequently provide one of the most efficient interconnected pathways for ground water flow. The joint sets measured and described during this investigation and their relationship to structural features will be discussed in a separate section.
Early Folds and Faults
The schist. gneiss, and amphibolite north and south of the Towaliga Fault Zone have endured a polydeformational history. Theserocks have a penetrative schistosity (S 1),expressed primarily as the alignment and concentration of biotite and/or
muscovite in the gneiss and muscovite sillimanite in the
quartzite and schist S1 is generally observed parallel with layering that is believed to represent the original compositional layering (So). The intensity of S1 foliation is variable, being more intensein the schistandquartzite than in the gneissic units. A summary plot of measured regional foliation orientations is given in Figure4. The calculated mean foliation (S 1) is N81 E, 51 o NW. A lineation (L1) observed in units north and south of the Towaliga Fault Zone is a nonpenetrative mineral lineation defined by the preferential alignment of feldspar and biotite along S1 planes. This lineation trends N52E, 2040SW and is consistent with that recognized by Grant (1967).
Tight to isoclinal style folding (Fl) associated with axial planar S1and L1, is locally observed in all rock types north and south of the TowaligaFault Zone. These fold sets trend WNW to ENE (averaging N84E), have a shallow plunge (5-20) to the southwest and axial planes dip to the north 10-35 degrees. The best exposures of the tight sequence ofisoclinal folding is in the Hollis quartzite where the schistose interlayers provide excellent marka- beds. Additionally, variability offoliation in the garnetiferous biotite gneiss indicates a series of tight folds throughout the southern half of the quadrangle.
Effectsofprobable thrustfaulting associated with isoclinal folding wa-e also observed A thrust contact has been interpreted between the porphyroblastic gneiss and gondite/graphite-sillimanite schist sequence by Higgins and Atkins (unpublished mapping). A narrow (2 to 3 em) layer of oxidized clay occurs at the contact between an abrupt change in lithology (gneiss andgondite/schist) and a change in the average foliation (Sl) orientation to N65E. This zone may represent the plane of movement Given the juxtaposition of two different lithologic units that are not in their normal stratigraphic sequence, the possible clay-filled fault zone, and the abrupt change in structural attitude, the interpretation of a thrust contact seems reasonable.
The two thin units of quartzite and interlayered kyanitegarnet schist are tentatively interpreted as an imbricate thrust slice off the main Hollis quartzite. The average foliation orientation in the northern-most thin quartzite unit changes from N80E to N60"E in the last 3.5 km before its northeastern termination. This change is consistent with a change observed in the trend of the Towaliga fault As indicated on Plate 1, the sequence of the thin quartzite units and interlayered kyanitegarnet schist and the main section of Hollis are all enclosed within the same unit (augen gneiss). These thin quartzite units have previously been interpreted as discontinuous cataclastic and mylonitic zones created during movement along the Towaliga Fault Zone and were not believed to be related to the Hollis quartzite (Hewett and Crickmay, 1937; Grant, 1967; Higgins and Atkins, unpublished mapping). This is a viable interpretation; however, by considering that: I) locally, the units are indistinguishable mineralogically and texturally from the main Hollis quartzite and associated Manchester Formation, 2) the units grade laterally into cataclasites which are commonly associated with thrust faults; and 3) repetition ofthe lithologic sequence is indicated; the interpretation that the quartzite-schist sequence represents an imbricate thrust off of the Hollis is well supported. Alternative interpretations including effects of repetition by folding have also been considered. The repetition of the lithologic sequence could have been produced during the Fl isoclinal event Unlike the main body of quartzite, mesoscopic folding is not indicated in the thin quartzite units in outcrop. However, effects of thrust faulting are indicated at outcrop scale in the surrounding gneiss and schist; therefore, repetition of units by imbricate thrusts is currently the favored interpretation.
A second generation of broad, open-style folding (F2) gently warps the isoclinal folds, locally. This event was not penetrative, however, as the SO/S 1 layers appear to be unaffected (i.e., no associated S2 is recognized).
Towaliga Fault Zone
The Towaliga Fault Zone, which is interpreted to be younger than the regional foliation (SO/S1), is oriented N60 to 70E, 50-70 NW. The fault woe is characterized by a variably exposed width of ductile deformation ranging from 1 to 3 km on the Barnesville quadrangle. The fault wne is also characterized by a prominent stretching mineral lineation (1.2)
8
trending N25W, and plunging 49 to the northwest and is conSistent with that documented by Grant (1967). This stretching lineation was probably developed in response to dip-slip movement along the Towaliga Fault Zone. Figures 5 and 6 are sumrnaryplotsofallfoliationmeastD'elllents within theTowaliga Fault Zone and the one-mile radius around the research site, respectively. Thedistributionofpolesonfigure's4,5,and6are very similar, indicating that the orientation of shear-induced foliation (S2) is so similar to regional foliation that it is indistinguishable from S1 on a composite plot.
Alater,brittle stageofmovementalong the TowaligaFault is locallydepicted inazoneofoffsetwhere the shearednorthern thinquartziteunitisjuxtaposedagainstthegarnetiferousquartzmuscovite schistwith a narrow zone offault gouge dividing the two units. The attitude of this fault is N70E, 80NW and parallels that of the Towaliga Fault
The northern margin of the Towaliga Fault Zone, charncterized by augen gneiss, mylonitic schist, and local cataclasite, has a relatively abrupt contact with adjacent rock units. Augen gneiss, mylonitic schist and quartzite, and cataclasite also characterize the southern margin of the Towaliga Fault Zone, but narrow zones of high strain subparallel to the main zone occur sporadically up to 3.5 km south of the margin. This is indicated by the occurrence ofdiscontinuous cataclastic lenses and interlayers of mylonitic schist in the garnetiferous biotite gneiss. These lenses and interlayers maintain a similar shear foliation orientation (N65E) as that observed in the Towaliga FaultZone. These shearfeatures indicate thatductile and brittle
movement occurred within and south of the Towaliga Fault Zone; subsequently, these units were juxtaposed against the relatively unsheared units north of the Towaliga Fault Zone. The central portion of the Towaliga Fault Zone consists of extensive cataclasites, brecciated cataclastics, augen gneiss, mylonitic gneissic schist and quartzite, and ultramylonitic gneiss.
Shear zones are typically very heterogeneous internally. Structural discontinuities tend to intersect at acute angles producing an anastamosing anay ofshears that envelope zones of lower strain (Bursnell, 1989). Effects of shearing are heterogeneously distributed throughout the Towaliga Fault Zone. This is indicated most clearly around the sheared gneissic schist units and in the drill core from the hydrogeologic research site. The sheared gneissic schist has been observed to occur within the augen gneiss and locally along the quartziteaugen gneiss and quartzite-garnetiferous biotite gneiss contacts. A fainter foliation plane occurs in the sheared gneissic schistand its combination with S1probably promoteddevelopment of the button schist fabric within the sheared gneissic schist This foliation (S2?) was not developed well enough, however, to obtain a reliable measurement As mentioned in the lithologic descriptions, the sheared gneissic schist and augen gneiss are very transitional units, possibly originating from the same protolith. It is conceivable that during shearing and accompanying fluid infiltration of a gneissic unit, feldspar content would decrease and muscovite content would increase due to crystallization from breakdown of feldspar. Addition-
Ill
SCHttiDT POLE CortCEttTRATIOHS
i: of" total per
1.0 S area
c: 0
:II
c: 2
c: ...
*
:a
c: 6
'lK
'lK
c: 10
ill
c: 12
ll!:
!<IJ
-E
c: 1"1
*
LNFL HEtti SPHERE
2"18
POLES
2-48 ENTRIES
NO BIAS CORRECTION
""';;;>~
FIGURE 4. Contoured, lower hemisphere, equal-area stereoplot of
248 poles to foliation outside the Towaliga Fault Zone. The solid
black area represents the maxima and indicates that 12% to 14 %
of the data occur in an area equal to one percent of the total area
of the diagram. The calculated mean regional foliation is N81 E,
51NW.
9
SCHHIDT POLE
:CIIOoNrCEtNoTtR.-A1TIOpNaSr
.. 1.0 ill area c: 0
c: 2
lt
< ""
Ill
<! 6
:II
c: a
Ill
< 10
Ill
< 12
:II
< 1""
:II
LWFI. HEMISPHERE
167
POLES
167 ENTRIES
NO BIAS CORRECTION
FIGURE 5. Contoured, lower hemisphere, equal-area stereoplot of 167 poles to foliation within the Towaliga Fault Zone. The calculated mean foliation within the Towaliga Fault Zone is N77E, 50NW.
SCHHIDT POLE COHCEJ'ITRAT IONS :II of total per
t.O :II area
< 0
:II
< 2.5
lt
c: 5
t!
< 7.5
:II
< to
:II
< 12.5 21
c: 15
~
-E
" c: 17.5
LWR. HEHISPHEFE
t""t
POLES
t""t ENTRIES
NO BIAS CORRECTIOH
$
FIGURE 6. Contoured, lower hemisphere, equal-area stereoplot of 141 poles to foliation in a one-mile radius around the Barnesville hydro~eologic research site. These data primarily lie within the Towahga Fault Zone. The calculated mean foliat1on within this radius is N78E, 50NW.
10
ally, biotite would initially become more highly concentmted, imparting a more schistose fabric to the gneiss, and ultimately the biotite would be depleted due to interaction with shearinduced fluids. The resultant"sheared schist-gneiss" wouldbe mineralogically similar to the original gneiss (with the exception of relative mint'Lal abundance), and texLUrally similar to a sheared schist The sheared gneissic schist may represent portions ofthe augen gneiss l.hat have been sheared to agreater degree, perhaps as a result of anastomosing splays within the TowaligaFaultZone. Alternatively, the sheared gneissic schist may simply represent compositionally discrete intedayers of schist within the gneiss, both of which have undergone intense shearing.
Heterogeneous effects of shearing in the Towaliga Fault Zone are also observed in diamond drill holes GGS#3637 and GGS#3638. Drill corefrom GGS#3637 represents a 328.5 foot penetration of the augen gneiss. The upper half of this hole consists ofaugened and ribboned gneiss. Below 170 feet, this unit grades into a zone of greater penetmtive deformation as evidenced by the gradual development of a mylonitic flow fabricalongwilhcomminutionofaugenstomicroaugens. Very locally, blastomyJonite is observed and probablyrepresents the advent of movement along the Towaliga Fault Zone (Gnmt, 1967). The bottom portion ofthis hole encountered alternating intervalsofultmmyloniteandcataclasites. DrillholeGGS#3638 is collared in micaceous, mylonitic quartzite and represents the northern-most of the thin quartzite units. This unit is followed by an interval of intense brecciation and veining. The breccia consists ofnwnerous randomly oriented clasts ofschist, quartzite, vein quartz and sillimanite needles. This breccia may represent the area where the southern and northern quartzite limbs merge, as observed in surface exposures. Sixty feet of cataclasite with transitional zones of mylonitic quartzite were encountered below the brecciation, and another zone of brecciation follows the cataclasite. The bottom portion of the hole is characterized by an interval of gradational cataclasite, mylonitic quartzite and mylonitic schist, all containing vein quartz.
METAMORPIDSM
The metamorphic mineral assemblages obSt'LVed north of the TowaligaFaultZone appear to vary with bulk composition. The graphite-sillimanite schist is characterized by graphite + sillimanite + garnet + muscovite + feldspar + quartz biotite; whereas, the gneiss contains biotite+ feldspar+ quartz. During this field investigation, garnet has not been observed as part of the metamorphic assemblage in the gneiss; however, Grant (1967) reported the rare occurrence of garnet in this unit Although no geothermometry has been obtained, based on mineral assemblages, the metamorphic signature in this area is characterized as sillimanite zone ofthe almandine-amphibolite facies (Mason, 1978).
The metamorphic mineral assemblages observed within and south ofthe TowaligaFaultZone differ from those north of the Towaliga Fault Zone by the occurrence of kyanite in the schist and abundant garnet in the gneiss. The kyanite-gamet
schist, gametiferous schist, and sheared gneissic schist are characterized by muscovite + feldspar + quartz + kyanite + garnet biotite and the augen gneiss and gametiferous biotite
gneiss are characlerized by garnet+ muscovite + biotite +
quartz + feldspar:. Quantitative data are not available for geothermometiy based on garnet-biotite equilibrium pairs; therefore, qualitatively, this area is preswned to have achieved staurolite to kyanite-grade metamorphism( Mason, 1978).
HYDROGEOLOGY
426 foliation and 519 joint measurements were taken during the geologic mapping segment of this investigation
(Plates 1and 2). Before gathering joint data. each outcrop was
visually assessed to identify the most prominentjointsets. This qualitative method offiltering data could have been perfonned quantitatively and statistically by measuring all joints present and plotting them on appropriate structural diagrams for each outcrop. This approach has previously been taken by various consulting finns in the region; however, the results are essentially the same as those acquired from the qualitative method and the quantitative method takes significantly longer.
Structural data collected at each outcrop includes orientation of foliation and/or compositional layering, joint sets, lithologic contacts, veins, folds, and faults. Additional characteristics ofpotentialhydrogeologic significance, such as degree and depth ofweathering, and spacing, persistence, and dilation of joint sets were recorded for the structural discontinuities where applicable. Lithologic features such as mineralogy also have a hydrogeologic impact and are discussed in the Lithologic Descriptions portion of this repon. These structural and lithologic data are presented in Appendix I.
A variety of methods are used to compare structural data; the most effective are stereonets and rose diagrams. These types of graphical representation enable quick assimilation of data and allow directcomparison ofstructural trends. Although there is significant scatterin the data, a few generalizations can be made for prominent joint orientations related to different lithologies and different geographic locations, relative to the Towaliga Fault Zone.
Joint set data are categorized by two criteria: 1) lithology, and 2) relation to the .Towaliga Fault Zone (i.e., south, within, and north of the Towaliga Fault Zone). Dominant joint orientations are indicated in seven of the ten lithologies described. Eighty-five percentofthe lithologies display a broad northwest joint set with a strong north-northwest subset This orientation is generally perpendicular to the regional foliation (Sl). Another weaker joint set oriented roughly northeast occurs in 70% of the lithologies. This orientation is generally parallel to S1. Two minor, north-south and east-west sets are also observed in 70% of the lithologic units. Many of these joints are vertical; however, some depart up to 30 from this attitude. These four
dominant joint sets are commonly observed in crystalline rocks
throughout the Georgia Piedmont (Crawford, T., pt'L. comm., 1991).
Joint orientations were also arranged by geographic position relative to the Towaliga Fault Zone (Plate 2). North of the
11
SCH"IDl' POLE CONCEttTRATIOHS :15 of total per
1 , 0 21 area
< 0
lis
< 1
"'
c 2
:II
c 3
:II
c ""
'!I!;
< 5
115
c: 6
:15
E
c 7
:15
LWR. HEMISPHERE
331
POLES
331 ENTRIES
NO BIAS CORRECTION
FIGURE 7. Contoured, lower hemisphere, equal-area stereoplot of 330 poles to joint surfaces outside the Towaliga Fault Zone. The most prominent joint set has a broad, northwest orientation with a strong north-northwest subset. Minor areas of 3-4% mark subsidiary sefs of joints orientated northeast and east-west. The symmetrical placing of the maxima near the perimeter indicate that the joints are
commonly near vertical.
J!l
SCII~IDT POLE COHC NTR~TlONS
:15 of' total per
1.0 \II .ar ea
c: 0
s
c 1.5
~
< 3
:.t
:t
s
< 7.5
z
c 8
z
~!
E
< 10 . 5 :1;
LWR HEI'II SPHERE
175
POLES
175 ENTRIES
NO BIAS CORRECTION
FIGURE 8. Contoured, lower hemisphere, equal-area stereoplot of 175 poles to joint surfaces within the Towaliga Fault Zone. The dominant joint sets within the Towaliga Fault Zone are oriented north-south. Minor northeast and east-west oriented sets are indicated by the 3-4.5 % area.
12
Towaliga Fault Zone, joint sets have a prominent broad northwesterly orientation with anorth-northwestsubsetanda weaker northeastezly orientation (Fig. 7). Near the margin and within the Towaliga Fault Zone, the dominant joint set is roughly north-south to north northeast (Fig. 8). This set may represent fracturing in response to latent stresses associated with dip-slip movement along the Towaliga as it is oriented parallel to the stretching lineation (L2) observed during this investigation and noted by Grant (1967). Other joint sets in the Towaliga Fault Zone include the east-west orientation and a weaker northeasterly and northwesterly alignment (Fig. 8). Joint orientations sorted for an area within a one mile radius ofthe hydrogeologic research site within the Towaliga Fault Zone display strongly shear-controlled fabrics. The two dominant joint sets include a north-south and a northeast set (Fig. 9). The northeast orientation is only observed as a dominant joint set within the one-mile radius. These two sets probably represent fracturing in response to latent stresses associated with dip-slip (L2) and strike-slip (S2) movement along the Towaliga Fault Zone, reSpectively.
South of the Towaliga Fault Zone, the dominant joint sets are analogous to those observed north of the Towaliga Fault Zone, and are characterized by a prominent broad northwesterly and weaker northeasterly, and east-west orientations (Fig. 7). The symmetricalplacingofthe maxima on theperimeteron Figure's 7, 8, and 9, indicates that the joints, though somewhat variable, are statistically near vertical.
Gorday (1989) performed a rectilinear stream analysis of
LamarCounty inconjunction with ahydrogeologic studyofthe area. Gorday observed three dominant directions of streamsegment alignment These regional stream-segment orientations parallel three ofthe four jointsets commonly observed on the Barnesville quadrangle, indicating a structurally controlled drainage pattern. On a quadrangle and smaller scale, the relationship of stream-segmentalignmentand planar weakness varies in different rock types. Commonly, streams occur bisecting intersections ofplanar features (i.e., two joint sets, or one joint set and foliation) in quartzite and biotite gneiss; whereas, in schistose units, streams tend to occur parallel to planar weaknesses. Although this observation is empirical, the relationship may bear potential hydrologic significance.
Generalizations concerning frequency and abundance of fracturing for a given lithologic unit or geographic position are more difficult to make. These types of generalizations may be biased by the amount ofexposure and degree of weathering as well as a response to a particular rock type or the stress field of a specific area. Thegreatestfrequency ofoutcrops occurs in the sheared gneissic schist, augen gneiss, cataclasite and quartzite. All ofthese units occur within oradjacent to the TowaligaFault Zone and have the greatest concentration of penetrative joint sets. These observations could indicate the following: I) the abundance of well-developed joint sets in this band of rocks within the Towaliga Fault Zone does not necessarily indicate that these rock types were more amenable to fracturing than otheJ" lithologic units south and north of the Towaliga Fault Zone. The units appear more resistant to weathering, possibly
SCHI'IIDT POLE CONCENTRATIONS ~ of' total per
t.O ~area
< 0
~
< 1.5
::Ill
< 3
::Ill
< "1.5
:II
< 8
:II
< 7.5
'I!
< 9
::Ill
.E
< 10.5 ~
UIR . HEtti SPHERE
153
POLES
153 ENTRIES
HO BIAS CORRECTION
FIGURE 9. Contoured, lower hemisphere, equal-area stereoplot of 153 poles to joint surfaces within a one-mile radius around the Barnesville hydrogeologic research site. The dominant joint set is oriented north-south and is similar to that observed within the Towaliga Fault Zone. A strong northeast orientation is also indicated and is unique to the area.
13
due to partial silicification, thus jointing is more evident than in contrasting rheology are adjacent to one another.
deeply weathered outcrops. For example, the porphyroblastic
2. A penetrative regional schistosity is expressed through-
gneiss does not have a high occurrence of outcrop, but when out the field area (S 1: N81E, 51NW) and is generally devel-
exposed. this unit is usually fairly well fractured 2) Because oped parallel to compositional layering. This regional foliation
these rock types are more resistant, they react brittlely to latent is locally variable and is associated with effects of isoclinal
stress fields; consequently,they are moresusceptibleto second- folding and thrust faulting. Isoclinal folds trend WNW to ENE
ary fracturing. This bandofrocks traverses westto eastthrough {averaging N84E) and plunge gently ranging from 5 to 20
the center of the one mile radius around the hydrogeologic degrees. A regional mineral lineation (Ll) observed by Grant
research site. Even though the frequency and abundance of (1967) and during this investigation, is axial planar with the
joint sets appears to be greater in this area, determination of isoclinal folds.
whether or not this is a function of the units' proximity to the
3. TheTowaligaFaultZoneisanareaofmajordistributive
TowaligaFaultZone is difficult to make. However, because of movement, extending from eastern Alabama through central
the inherent heterogeneous distribution of rock types and Georgia. This zone is interpreted to be younger than the
silicification in the one-mile radius, this area would intuitively regional foliation and strikes N60-700E across the central
seem to be favorable for a higher concentrationofjointing. This portion of the Barnesville quadrangle. The Towaliga Fault
high frequency ofjointing is probably responsible for the high Zone dips 50 to 70 degrees to the north, and has a variably
yield well at the research site.
exposed width ofl to 3km. A stretching mineral lineation (L2)
The scatter in joint orientation data may be related to trending N25E, 49NE is consistent with that observed by
locally different inherent variations in the rock fabrics. Despite Grant (1967) and is probably associated with dip slip move-
effects of polydeformational events, regional foliation (S 1) is ment along the Towaliga fault
generally planar; however, the attitude of foliation does vary.
4. Heterogeneous effects ofshearingoflithologic units are
Many joint sets appear to have formed in response to the manifested by texture and mineralogy. Texturally, select
foliation orientation; therefore, wide variation in joint set portions of the quartzite, kyanite-gametschistand augen gneiss
orientation may be a function of variations in foliation dip and have been mylonitized to various degrees, and cataclasized.
dip direction. Therefore, a slight change in one foliation Effects of late brecciation and subsequent partial to complete
orientation may moderately affect three or four joint orienta- infilling by inwardly projecting quartz crystals are seen in the
tions. When joints measured from a larger geographic area are quartzite and augen gneiss. Locally, these breccia zones are
combined, more scatter is introduced due to the larger statistical associated with cataclasites, but are more commonly observed
variation in foliation; consequently, generalizations made on a in mylonitic quartzite. Mineralogically, alterations due to
large scale may not be applicable to the outcrop scale. Given shearing include the crystallization of muscovite from feldspar
this understanding, it is fairly swprising that even weak gener- in the shearedgneissic schistand augen gneiss, and local partial
alizations can be made at this scale. This does not, however, to pervasive silicification of the augen gneiss, quartzite, and
preclude the attempt to model effects of different geologic cataclasite.
systems with hydrologic characteristics. To develop a predic-
5. Lithologic units north of the Towaliga Fault Zone
tive model to effectively locate high yield wells, comprehen- appear to have achieved sillimanite-grade metamorphism. In
sivegeologic characterization ofan area mustbe systematically contrast, lithologic units within and south ofthe TowaligaFault
compared and correlated to hydrologic data from the immedi- Zone appear to have achieved kyanite-grade metamorphism.
ate area. Additionally, stronger correlations and consequently
6. Because of the great variability of rock types, it is
more useful information can beobtainedon a smaller, more site difficult to characterize the depth of weatheruig for each
specific scale, where the variation of interaction between lithologic unit However, in a general sense, the unsheared
foliation and joint development is minimized.
gneissic units (porphyroblastic gneiss and gametiferous biotite
gneiss) are more deeply weathered than the schist (quartz-
CONCLUSIONS
muscovite schist, gametiferous schist, kyanite-garnet schist),
and the schist is more deeply weathered than the quartzite. The
1. Eleven lithologies were mapped on the Barnesville massive central portion of the quartzite is much more resistant
quadrangle: graphite-sillimanite schist, gondite, quartz-mus- than the flanks where the quartzite becomes interlayered with
covite schist, porphyroblastic gneiss, sheared gneissic schist, schist The sheared gneissic schist is generally more resistant
augen gneiss, cataclasite, kyanite-garnet schist, gametiferous to weathering than the augen gneiss (depending on amount of
schist, quartzite, gametiferous biotite gneiss. Seven of these silicification) and less resistant than the quartzite. The only
lithologies were mapped in detail within aone mile radius ofthe rock units that appear to be ubiquitously competent are the
Barnesville hydrogeologic research site: porphyroblastic gneiss, silicified cataclastic lenses where intense granulation has di-
augen gneiss, sheared gneissic schist, cataclasite, quartzite, minished grain size to a microscopic scale. This reduction in
kyanite-gamet schist, garnetiferous biotite gneiss. Four of grain size has taken place under high pressure conditions;
these lithologies were encountered in the two core holes: therefore, therock remains highly competentand is notreduced
sheared gneissic schist, quartzite, augen gneiss, cataclasite. All to a fine powder.
units have highly variable weathering characteristics. This
7. 519 joint measurements were taken throughout the area.
differential weathering is particularlyevident when two units of Fourdistinct orientations are dominant amidst abundant scatter
14
of data: northwest with a north-northwest subset, north-south, east-west, and northeast The northwest, east-west and northeastsetsappear to be slightly morepervasive north and south of the Towaliga Fault Zone, and the north-south set appears to be more pervasive within the Towaliga Fault Zone. Three of the four dominant joint orientations are paralleled by dominant drainagepatterns in LamarCounty. The variabledominance of joint sets is most likely a function of the most influential local
rock fabric (foliation, lineation, fold axes). These generalizations, however, are probably not reliable on a site specific scale
and should not be used as a tool for depicting hydrogeologic
characteristics of a specific area.
8. Generalization concerningfrequency and abundance of fracturing for a given rock type or geographic location are difficult to make. Thelithologic units within theTowaligaFault Zone ( and the one-mile radius around the research site) apparently have more joint sets developed than in rock types north and south of the Towaliga Fault Zone. This relationship may be a function of abundance of outcrop: rocks within the TowaligaFault Zone are much better exposed than rocks north and south of the Towaliga Fault Zone. Where lithologic units north and south of the fault zone crop out (specifically the porphyroblastic gneiss and garnetiferous biotite gneiss), they generallycontain numerousjointsets; therefore, itis difficult to determine whether occurrence and abundance of jointing is enhanced in shear zones.
REFERENCES CITED
Grant,W.H., 1967,GeologyoftheBamesvilleareaandTowaliga Fault,LamarCounty,Georgia: GeorgiaGeologic SurveyGuidebook6, 16p.
Hewett, D.F., and Crickmay, G.W., 1937,The warm springs of Georgia, their geologic relations and origin: U.S. Geological Survey Water Supply Paper 819, 40p.
Higgins, M.W., 1971, Cataclastic rocks: U.S. Geological Survey Professional Paper 687, 96 p.
Higgins, M W.,and Atkins, R.L., unpublished geologic map of the Barnesville 7.5 minute USGS quadrangle, Lamar Co., Georgia
Higgins, M.W., Atkins, RL., Crawford, TJ., Crawford, R.F., Brooks, R., and Cook, R.B., 1988, The structure, stratigraphy, tectonostratigraphy, and evolution of the southernmost part of the Appalachian Orogen: U.S. Geological Survey Professional Paper 1475, 173 p.
Hooper, RJ., and Hatcher, R.D., 1989, The geology ofthe east end of the Pine Mountain Window and adjacent Piedmont, central Georgia: Geological Society of America Pre-meeting Field Trip Guidebook for Southeastern Section, 35 p.
Lister, G.S. and Snoke, A.W., 1984, S-C mylonites: Journal of Structural Geology, v. 6, p. 617-638.
Atkins, R. and Lineback, J., 1992, Structural relations, origin andemplacementofgraniticrocksin the CedarRock Complex, Georgia Piedmont: Georgia Geologic Survey Bulletin 115, 40 p.
Bentley, R.D., and Neathery, T.L., 1970, Geology of the Brevard fault zone and related rocks of the Inner Piedmont of Alabama: Alabama Geologic Society Guidebook for 8th Annual Field Trip, p.32-36.
Bursnell, J.T., 1989, Review of mechanical principles, deformation mechanisms and shear zone rocks: Geological Association ofCanada Short Course Notes Vol. 6, p. 1-27.
Clarke, J.W., 1952, Geology and mineral resources of the Thomaston Quadrangle, Georgia: Georgia Geologic Survey Bulletin 59, 103 p.
Crickmay, G.W., 1952, Geology of the crystalline rocks of Georgia: Georgia Geologic Survey Bulletin 58, 56 p.
Favilla,LJ., 1985,Agravity surveyofLamarCounty, Georgia: Georgia Geologic Survey Open-File Report 86-3, 33 p.
Mason,R., 1978,Petrologyofthe MetamorphicRocks: George Allen & Unwin.
Pickering, S.M., Jr., 1976, Geologic Map of Georgia: Atlanta, Georgia Geologic Survey, scale 1 : 500,000.
Sears, L.W., Cook, R.B., Gilbert, O.E., Carrington, TJ., and Schamel, S., 1981, Stratigraphy and structure of the Pine Mountain Window in Georgia and Alabama: Georgia Geologic Survey Information Circular 54-A, 41-53 p.
Secor and Snoke, 1986, Character of the Alleghanian orogeny in the Southern Appalachians: Part III Regional tectonic relations: Geological Society of America Bulletin V. 97, p. 13191328.
Sibson, R.H., 1977, Fault rocks and fault mechanisms: Journal of the Geological Society of London, v.133, p. 191-213.
Steele,W., Brackett, D., and Kellam, M., and Hall, M., in prep., Hydrogeology of the Barnesville hydrologic research site, Lamar County, Georgia: Georgia Geologic Survey Information Circular 93.
Gorday, L.L., 1989, The hydrogeology of Lamar County, Georgia: Georgia Geologic Survey Information Circular SO, 40 p.
15
APPENDIX I Foliation and Joint Data
Appendix I represents the compilation of select structural and lithologic data gathered during the field portion of this investigation. The easting and soothing coordinates for each map station where data were recorded are measured from an arbitrary 0,0 reference point (scale: 1" = 1001located at the northwestern comer of the quadrangle (Plates 1 and 2). The lithologic and structural abbreviations used on this table are listed below.
Rx Type= rock type Pol = foliation Space= spacing measured between joints Persist = persistence of joints Dilat = relative degree of dilation along joints Weath = weathering characteristics ofjoints D = dilated joint SD = semi-dilated joint Fe, Mn =Fe and Mn oxide staining Bleach = bleached halo around joint KAOL = kaolinite infilling of joint Si01 = quartz infilling of joint Lithologies
GSS =graphite-sillimanite schist
QMS = quartz-muscovite schist BQFG = biotite-quartz-feldspar gneiss GQMS = garnetiferous quartz-muscovite schist AMPH = amphibolite
QGG =quartz-garnet granofels (gondite) Q1E =quartzite
GBQFG = garnetiferous biotite-quartz-feldspar gneiss SBQFG= shearedan<Vorsilicifiedbiotite-quartz-feldspar gneiss SSG = sheared gneissic schist FCR =flinty crush rock (cataclasite) GKQMS = garnetiferous kyanite-quartz-muscovite schist IP = igneous pegmatite
16
Map Sta
1
2
2 3
4
5 5
5
6
7
8
8
8
9
10 10 10 10 11 11 11 11 12 12 12 12 12 13 13 13 13 13 13 14 15 15 15 15 16 16 16 16 16 17 17 17 18 18 19 19 19 19 19 19 19 19 19 20 20 20 20 21 22
22
22
22 22 22 22 23
Eastlng
soo
485 485
435
418
405
405
405
355
355
360
360
360
355 395 395 395 395 470 470 470 470 530
530 530 530 530 570 570 570 570 570 570 650 265 265 265 265 220 220 220 220 220 125 125 125 145 145 275 275 275 275 275 275 275 275 275
265
265
265 265 195 175 175 175 175
175 175 175 145
Southlng Rx Typ
60 ass
82 GSS
82 GSS
345 OMS
285 OMS
230 BOFG
230 BOFG
230 BOFG
140 GOMS
110 GSS
55 GSS
55 GSS
55 GSS
20 GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0 AMPH
0 BOFG
0
BOFG
0 BOFS
0 OMS
35 BOFG
35 BOFG
35 BOFG
35 BOFG
35 BOFG
35 BOFG
270 BOFG
485 BOFG
485 BOFG
485 BOFG
485 BOFG
510 BOFG
510 BOFG
510 BOFG
510 BOFG
510 BOFG
505 OMS
505 OMS
505 OMS
500 OMS
500 OMS
270 BOFG
270 BOFG
270 BOFG
270 BOFG
270 OMS
270 OMS
270 OMS
270 OMS
270 OMS
255 BOFG
255 BOFG
255 BOFG
255 QGG
190 GSS
160 GSS
160 GSS
160 GSS
160 GSS
160 GSS
160 GSS
160 GSS
125 GSS
Fol Trend
N69E N64E N84E N25W N21W N38E N50E
N6W
N27E N4E
N85E N34E N19E
N54E
N70E
N44W N60W NSOW N38W N75E
N58E N72E
N60W N30E N28E
N35E N20W
Fol Dip
39NW 14NW 45SE 14SW 30SW 15NW 30NW
49SW
56NW 18NW
64SE 40NW 17NW
48NW
23NW
15SW 20SW 22SW 18SW 32NW
10NW 24NW
10NE 18NW 39NW
28NW 44SW
FOLD FOLD FOLD FOLD FOLD
FOLD FOLD
Trend Dip Plunge
NOW 90E
N42W 85NE N37W 89SW
NBOW N45W 84NE N72W 71NE N45E 72NW N13W 69NE
BONW
N40W 80SW
N22W 76NE
N65W
26SE
N52W 66NE N37E BBNW N26W 83NE N30E N75W 85SW N10W 56SW N8W N33W BONE N52E N75W 89NE N45E 89NW N15W 89NE N31W BBNE N60E 76SE N45E 13SE N10W 84SW NBOE 66NW N70W 72NE N52W BONE
29SW
50NW 15NE
N33W 85SW N43W 73SW N12E 66NW N40W 70NE N30W 82NE N52W 81NE N47W 73SW N29W 82NE N12W BONE NBOW 89NE N60W 18SW N72W 66NE N7E 77NW N10W 80SW N75E 32NW N25W 80SW
N55W eosw
N75E BONW N61W 81NE N51W 86NE N72E 24NW N10E BONW N85W 32NE N20E 82SE N20E 75SE N5E 75NW N10W 78NE
N73W N85E 73NW N75E 87SE N45W 62SW N19W 89NE N20E N82W 86NE N70E 90W
28SE 24SW
Joints Space Persist Dllat.
Weath.
4" 24-36" D
OPEN
CLOSED
CLOSED
so
Fe
2"
6"
D FE.MN
2-8"' 36-48"
D
OPEN
30" 1.5" 36" 2-6" 24"'
D
D
MN
BLEACH
D
FE
4-8"
6" CLOSED
D
KAOL
D
KAOL
D
KAOL
D OPEN
96"
12"'
6''
48"
D
OPEN
1" 12"'
D
1"' 12"' so
FE
6'
6''
D
FE
6"
6"
D
FE
CLOSED
CLOSED
12" 36'' CLOSED
12" 36'' CLOSED
12" 36"
so
FE
CLOSED
D
FE
3"'
12"'
D
FE
311
12"
so
FE
D
FE
1"' 120''
1"
60"
3"
3"' 36"
FE,SI02
D
SI02
D FE,SI02
D D
D
FE
9"
60''
D
FE
72" CLOSED
D
FE
D
FE
17
Map Sta 23 24 25 25 25 25 26 27 27 27 28 29 30 30 30 31 31 32 32 32 32 32 32 32 32 33 34 34 34 34 34 34 35 35 35 36 37 38 39 40 40 40 41 42 43 43 43 43 43 44 44 44 45 45 46 47 47 48 48 48 48 49 50 51 52 52 52 53 54 55
Eastlng 145 110 95 95 95 95 85 75 75 75 50 115 150 150 150 235 235 265 265 265 265 265 265
265
265 320 140 140 140 140 140 140 125 125 125 110 25
65
80 25 25 25 530 650 620 620 620 620 620 650 650 650 755 755 500 445 445 645 645 645 645 870 805 645 540 540 540 650 850 745
Southlng Rx Typ
125
GSS
80
GSS
50
GSS
50
GSS
50
GSS
50
GSS
35
OMS
15
BQFG
15
BOFG
15
BOFG
200
GSS
200
GSS
20
GSS
20
GSS
20
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
0
GSS
555 BOFG
555 BOFG
555 BOFG
555 BOFG
555
OMS
555
OMS
610 BOFG
610 BOFG
610 BOFG
615
OMS
605 BQFG
660 OMS
705 BOFG
870
OMS
870
OMS
870
OTE
360 BQFG
360
OMS
660 BQFG
660 BOFG
660
OMS
660 OMS
660
OMS
730 BOFG
730
OMS
730
OMS
705
OMS
705
OMS
645
OMS
810 BOFG
810 BQFG
1145 OMS
1145 OTE
1145 OTE
1145
OTE
1995 BOFG
2005 AMPH
2085 OMS
1995 GBOFG
1995 GBQFG
1995 GBOFG
1710 FCR
1775 BOFG
1635 BQFG
Fol Trend N13E N25W N15E
N54E N28E
N74E N48E N30E
N42E N79E N5E
N26E
N54W N63W N20W
N44E N8E N40E N39E N3E N45E
N58W N70W
N72W N64E NBOE N76E N26E
N70W N87E
N69W N65W
NBOW N21E
Fol Dip 84NW 34SW 30NW
38SE 23NW
45NW 46NW 55NW
59NW 20NW 32NW
35NW
13SW 15SW 8SW
26NW 38NW 33NW 17SE 31NW 29NW
10SW 11SW
33SW 40SE 35SE 73SE 33NW
38NE 45NW
50NE 19NE
81NE 12NW
FOLD FOLD FOLD FOLD FOLD
FOLD
Trend Dip Plunge N25E BONW
N55W 73NE N20W 68NE N15E 70SE
N43E N28E N78E N11W N85E N10W N55W N70E N30W N30E N52W N70W N10W N89E N30W N35E N50E N5E
78SE 90W 70SW 89NE 89NW 51NE 62SW 86NW
75NE 75NE 84SW 78SE 82SW
50NW 49SW
14SW 7SW 7SW
N47E N71W N25W N68W N70W N36W N20W N76W N40W
87SE 85SW 70NE 69NE BONE BONE 78NE 76NE 80SW
N10W 89NE
N40W N55E N35W NOW
85SW 89NW 89NE 88NE
N59W N15W N26W N74E NBOE
B4NE BONE 86SW 74SE 81NW
N36W 40NE N55W 51SW
N39W BONE N41E BONW
N20W BONE NOW 90E N2BE 89SE
N83E 73SE N16W 68SW N85E
12SW
Joints Space Persist
36"
Dilat. D
Weath. FE
4"
12"
D
MN,SI02
12"
D
FE
so
FE
3"
so
MN
MN
12"
1"
2"
12"
D
FE
2"
BO"
D
FE,MN
4"
72"
D
FE,MN
6"
6"
120"
D
FE,MN
6"
36"
so
OPEN
12"
4"
12"
SD
FE
24"
D
SI02
4"
24"
D
FE
4"
6" CLOSED
.5"
24" CLOSED MN
4"
18"
D
FE
5"
12"
18"
D
SI02
4"
SD
FE
2"
12'' CLOSED FE
2'
12"
2"
12" CLOSED
3"
12"
D
2"
5" CLOSED
2"
5" CLOSED
1"
24" CLOSED
.5"
24"
D
FE
2" CLOSED
75"
24" CLOSED
1"
12" CLOSED
3"
36'' CLOSED
24" CLOSED
24" CLOSED
2"
24"
D
OPEN
12"
24" CLOSED
18
Map Sta 56 57 58 59 60 60 61 61 61 61 62 62 62 62 62 62 62 62 62 63 63 64 64 64 64 65 65 65 66 66 66 66 66 66 66 66 67 68 68 68 68 68 69 69 69 69 69 69 69 69 70 70 71 71 72 73 73 74 75 75 76 77 77 77 76 79 BO BO 80 61
Eastlng 740 735 730 1035 1010 1010 810 810 810 810 1005 1005 1005 1005 1005 1005 1005 1005 1005 1010 1010 1115 1115 1115 1115 1200 1200 1200 1210 1210 1210 1210 1210 1210 1210 1210 1210 1210 1210 1210 1210 1210 1250 1250 1250 1250 1250 1250 1250 1250 1330 1330 1385 1385 1340 1310 1310 1310 970 970 1060 1240 1240 1240 1175 1355 1415 1415 1415 1475
Southlng Rx Typ
1550 GBOFG
1500 BQFG
1450 BQFG
615
IP
620
GSS
620
GSS
820 AMPH
820 AMPH
820 AMPH
820
GSS
1020 QTE
1020 QTE
1020 QTE
1020 QTE
1020 QTE
1020 SBOFG
1020 SSG
1020 SSG
1020 SSG
1000 GQMS
1000 GQMS
685 BQFG
685 BQFG
685 BOFG
685 BOFG
915
FCR
915
FCR
915
FCR
915
QTE
915
QTE
915
QTE
915
QTE
915
QTE
915
QTE
915
QTE
915
SSG
920 SBOFG
960
QTE
960
QTE
960
QTE
960
QTE
960
QTE
995 BOFG
995 BOFG
995
OMS
995
QTE
995
QTE
995
QTE
995
QTE
995
SSG
915
QTE
915
QTE
960
QTE
960
QTE
925 GKQMS
900 SBOFG
900 SBQFG
690 SBQFG
330
GSS
330
GSS
185 BOFG
290 BOFG
290 BQFG
290
GSS
560 BOFG
110
GSS
140 BQFG
140 BQFG
140 BQFG
1BO BQFG
Fol Trend N68W N70E N85E
N48E
N75E N47E N42E N50E
N42E N48W N45E N52E N62E N46E
N72W
N75E
N72E N74E N69E N75E
N85W N70E N86E N83W NOOE
N72E
N86W
N84E N63E N62E
N58E N65E N72W
N70W
N88E N57W N55W N86E N68W N87W N40W
N87W
N3W
FoiDip 20NE 16NW 10NW
70SE
66SE 26NW 20NW 24NW
14NW 18NE 25NW 27NW 25NW 32NW
21SW
88NW
68NW 65NW 52NW 60NW
70NE 42NW 21NW 22NE
20N
62NW 32NE 40NW 37NW 46NW
19NW 48NW 52NE
30NE
66NW 45SW 35SW 36SE 20SW 14SW 22SW
72NE
32SW
FOLD
Joints Trend Dip Plunge Space Persist Oilat.
Weath.
NOE 90W N2W 65SW
1.5" 6"
D
OPEN
N55W N20W N53E N55W N28E N8W N76E N29E N12W N44W
76NE
eosw
89SE 60NE 87NW 83NE 82NW 70NW 73NE 76SIN
36"
6"
D
SI02
2"
3"
3"
6''
D
SI02,FE
so
FE
2"
12"
1"
12"
D
MN,FE
so
MN
1"
6"
D
OPEN
.5"
1" CLOSED
1.5"
12" CLOSED
6"
>120" CLOSED
1.5" 6-6" CLOSED
N38W N68E N90W N20W N50W N15E N84E N59W N5E N85E N19W N50E N56E N16W N35W N30E
87NE 72SE 50N 82NE 74NE 85SE 60SE 57SW 48SE 66SE 88NE 67SE 32SE 90E 86NE 65SE
N50W N72E N12E N45E N58E
87SW 64SE 78SE 81SE 85NW
1"
6''
D
OPEN
6''
D
FE
12"
so
FE
2"
8"
so
OPEN
9"
3-4" CLOSED
12"
24"
D
OPEN
.25"
3" CLOSED
6''
5" CLOSED
6"
24" CLOSED
D
MN,SI02
5"
60" CLOSED
2-3"
60'' CLOSED
1"
>24"
7"
24"
D
OPEN
so MN,SI02
2-3"
6'' CLOSED
6''
18" CLOSED
.5"
60" CLOSED
29"
12" CLOSED
.5-1 " 96"
so
FE
N53E N69E N76W N45E
33SE 74SE 62SW 64SE
N22E NBOE N49E N14W
84NW 37SE 87SE BONE
N75E 39SE N30W 66SIN
N65W N65E N59W N58E N70W N25W N68E
46NE 85SE 56NE 85NW 85NE 72NE 83NW
N86E
N15W N50W N65E
BONE BONE 80SE
4SW
.5-1 " .5" 4"
48 CLOSED
24"
D
SI02
36''
D
OPEN
46"
D
OPEN
2"
12"
2.5"
12"
so
OPEN
so
OPEN
2-4'" 36-48" CLOSED
2"
>160'' CLOSED
6'' .5-1 "
1" 12"
.5-1"
1" .5-1''
5' CLOSED
6' CLOSED
6''
so
FE
36"
so
OPEN
4"
so
FE
1'" CLOSED
36''
D
OPEN
12"
so
FE
6''
D
OPEN
36"
48"
2"
2" CLOSED
6"
9"
0
OPEN
19
Map Sta 81 81 82 82 82 83 83 83 84 84 84 85 85 85 85 85 86 87 88 88 89 90 91 91 91 91 91 92 92 92 93 93 94 95 96 97 97 97 97 98 98 99 99 100 100 100 101 101 101 102 102 102 102 102 103 103 103 103 104 104 104 104 104 104 105 105 106 106 106 106
Eastlng 1475 1475 1490 1490 1490 1545 1545 1545 1570 1570 1570 1625 1625 1625 1625 1625 1690 1705 1750 1750 1805 1815 1790 1790 1790 1790 1790 1540 1540 1540 1625 1625 1700 1470 1470 1470 1470 1470 1470 1465 1465 1460 1460 1460 1460 1460 1485 1485 1485 1460 1460 1460 1460 1460 1410 1410 1410 1410 1460 1460 1460 1460 1460 1460 1460 1460 1450 1450 1450 1450
southlng Rx Typ Fol Trend
1BO BQFG
1BO BQFG
185 BOFG N15W
185 BQFG
185 BOFG
215 BOFG
N4W
215 BQFG
215 BOFG
235
BQFG
N22E
235 BOFG
235 BQFG
255 BQFG N20E
255 BQFG
255
GSS
N28W
255
GSS
255
GSS
290
GSS
N20E
295 BQFG N22E
305
GSS
N34E
305
GSS
N40E
320
GSS
N39E
320 BOFG
355
OMS
N55E
355
OMS
355
OMS
355
OMS
355 OMS
205 BQFG
205 BOFG
205 BQFG
115 BOFG
115 BOFG
25
BQFG
65
GSS
N76E
30
GSS
N62E
15
GSS
N65E
15
GSS
15
GSS
15
GSS
205 BQFG
205 BQFG
410
GSS
N72E
410
GSS
455 BQFG
455 BQFG
455 BOFG
545 SBQFG
545 SBOFG
545 SBQFG
715 BOFG N20W
715 BOFG N11W
715 BQFG
N10E
715 BQFG?
715 SBOFG
NOW
740
SSG
N50E
740
SSG
N49E
740
SSG
N65E
740
SSG
725
FCR
N28E
725 SBQFG N10E
725 SBQFG
725 SBQFG
725 SBQFG
725
SSG
N22E
BOO
OMS
N70W
BOO
OMS
840
OTE
N47E
840
QTE
840
OTE
840 SBOFG N54E
Fol Dip 50NE
25NE 27SE
34NW 82SW
62NW 12NW 61NW 52NW 75NW 10SE
60SE 70SE 65SE
63NW
60SW 28NE 20NW 35E 20NW 27NW 24NW 22NW 15NW
26NW 30NE 25NW
26NW
FOLD FOLD
FOLD
Trend N45E N60W N15W N85E
N60W
N65W N25W N75E N70E N30W N10E N30E N10E
Dip 90NW 90NE B9NE 89NW 89NE 88NE 85NE 88NW 77SE 89NE 88NW 73SE 82NW
Plunge
N24E N50E N49E N34E N40W N60W N82E N85E N20W N69E N38E N55E N70E N30W N4W N70W N85E N12W N10W N10W N45W N5E N90E N60E N30W N32W N30E N20E NBOE N85E N70W N62E N35W N75W N60E N32W N10E N45W N13W N85E N55W N55E N10E N85E N75W N55E N10W N85E N45W N58E N45E N2W N5E N5W N75E N25E
BOSE
84SE BONE 51NE 79NW 68NW 50NE 71NW 48NW 10SE
87SW 68NE 70SW BONW 70NE 82SW BONE 60NE 75SE 77N 77NW 86NE 66NE 52SE BONW BOSE 60SE ?ONE 72SE 85NE 60NE 47SE 77NE 85SE BONE 76NE 72SE 83NE 88NW 53NW 74NW 68SW 84NW 83SW 90NW 90NE 72SE 85SE ?ONE 78SE 70SW 45SE 65SE
51SW 18SW
25SW
Joints Space Persist Dllat
Weath.
18"
12"
D
OPEN
9"
6'' CLOSED
4"
8" CLOSED
4"
18" CLOSED
1"
6"
SO
OPEN
12"
24"
D
FE
1"
4" CLOSED
1''
4811
D MN, OPEN
48" 36-48"
D
OPEN
8"
12" CLOSED
9'' CLOSED
8"
36"
SO
FE
4-5"
12"
so
FE
6"' CLOSED
6-9"
36" CLOSED
2"
6''
so
MN
2"
12"
so
MN
2"
15" CLOSED
5-8" 30''
SO
OPEN
6"
10' CLOSED
1"
24"
6''
120'
SO
OPEN
1"
4"
SDS
OPEN
24-36" CLOSED
6"
12"
4"
2"
D
OPEN
1.5" 36"' CLOSED
.25"
18" CLOSED
2"
42"
D
OPEN
24"
72" CLOSED
12"
24"
D
OPEN
48" CLOSED
1,."
6'' CLOSED 6'' CLOSED
1" 3"
1" 2" 2.5" .5-2"
1.5" .5" 4" 1" 4"
6-12"
6"' 15" 48" 12" 6"' 3" 6'' 24" 6'' 36" 12" 12" 4" 36-48" 8"
SO CLOSED CLOSED CLOSED
MN,OPEN
CLOSED CLOSED
D D CLOSED D CLOSED CLOSED CLOSED D
OPEN OPEN OPEN
OPEN
.5"
6"'
D
OPEN
2.5"
2"
D
OPEN
1" 18-24" CLOSED
2"
12" CLOSED
.5"
18"
so
MN
20
Map Sta 106 106 106 106 106 106 107 108 108 109 109 109 110 110 110 110 110 110 111 111 111 112 112 113 113 113 113 114 114 115 115 115 115 116 117 118 118 119 119 119 119 120 121 121 121 121 122 122 122 122 123 123 123 124 124 124 125 126 126 126 126 127 127 128 128 129 129 130 130 131
Eastlng 1450 1450 1450 1450 1450 1450 1440 1435 1435 1445 1445 1445 1435 1435 1435 1435 1435 1435 1435 1435 1435 1465 1465 1510 1510 1510 1510 1555 1555 1610 1610 1610 1610 1720 1830 1885 1885 1840 1640 1640 1640 1745 1740 1740 1740 1740 1750 1750 1750 1750 1770 1770 1770 1625 1825 1825 1675 1690 1690 1890 1690 1660 1860 1650 1850 1610 1610 1650 1850 1755
Southlng Rx Typ
840 SBQFG
840 SBQFG
840 SBQFG
840 SBQFG
840 SBOFG
840 SBQFG
915
OMS
960
QTE
960
QTE
970
QTE
970
QTE
970
QTE
985
QTE
985
QTE
985
QTE
985
QTE
985
QTE
985
QTE
1065 SBQFG
1065 SBQFG
1065 SBQFG
885
SSG
885
SSG
860
SSG
860
SSG
860
SSG
860
SSG
835
SSG
835
SSG
820 SBQFG
820 SBQFG
820 SBQFG
820
SSG
1110 BOFG
1085 BQFG
1075 QTE
1075 QTE
820 SBQFG
820 SBQFG
620 SBQFG
820 SBQFG
810
SSG
780 SBOFG
780 SBQFG
780 SBQFG
780 SBQFG
710
QTE
710
QTE
710
QTE
710
SSG
665 SBQFG
665 SBQFG
665 SBQFG
660
SSG
660
SSG
660 SSG
625
SSG
550 SBQFG
550 SBOFG
550 SBOFG
550 SBOFG
665
SSG
665
SSG
700 SSG
700
SSG
775
SSG
775
SSG
730 SBQFG
730 SBQFG
815
SSG
Fol Trend N77W NSOW
N17W
N80E N85E N86W N45E N80W N83W N75W N70W
N80E N85E N54E N75E N88W N60E N60E N85E
N84E
N65W
N75W N80W N85W N80E
N78E N80W N53W
N72W N20E N30E
N72W
N10E N12W N34E
N40E N65E N84E N53E N42E
N42E N55E N50E
N55E
N40E
N7CNV
Fol Dip
23NE 35NE
29SW
25NW 34NW 29NE 20NW 16NE 29NE 20NE 38NE
6NW 21NW 37NW 37NW 32NE 22NW 35NW 35NW
21NW
44NE
55NE
SONE
25NE 43NW
36NW 47NE 53NE
43NE 33NW 31NW
43NE
26SE 10NE 26NW
34NW 53NW 35NW 43NW 44NW
34NW 49NW 25NW
29SE
24NW
43NE
FOLD FOLD
r ...nd
N65W N85W N5W N35E N65E N80W
Dip
72SW 80SW 76SW 69SE 70SE
Plunge 20NW
N55W N50E N85E
N40E
N45W N35W NOW N75W N10E N88W N50E N44E N30E N65E N40W
65SW 82NW 76NW
78NW
65NE 73SW 86SE 76SW 55SE
76SE 62SE 73SE 61SE 61NE
8NW
N22E NOE N35W N80E NOE N65W N15E N5E N75E
70SE 86W 71NE 88NW 88W 44NE 88SE 66NW 88SE
N30W N45E NOE N70E N37E N35W
88NE 66SE 69NE SOSE 85SE 77SW
N70E N5E N60W N30W N88E N5W N80E
63NW 74NW 32SW B6NE 53NW 35NE B6SE
N10E N35W N60W NSOE N5E
70NW 80NE 78NE 79SE 79SE
N45W N62E N8E N15W N18E N5W
90NE 87NW 76NW 64NE 56NW 70NE
N12W N50W N65W N23E N74E N2W
42NE SOSW 80SW SOSE 62SE 85NE
Space 1"
.5-1 "
6"
18"
2"
Joints Persist
4" 12" 24" 48" 36''
Dllat
0 0 0
so
Waath.
FE,MN MN,OPEN
MN MN
3" 311 1" 1" 1" 1"
. 5-2" 4"
2"
12" 1211 24" 36" 1-2" 4" 72-84" 6" 24"
CLOSED
SD
FE
D
SI02,MN
SD
FE
SD
CLOSED
D VQ,OPEN
CLOSED
CLOSED
1-2"
48"
0
30"
30"
so
1"
36"
0
24" 36-48"
0
1"
6"
FE,VQ OPEN OPEN open
12"
24"
D
OPEN
2"
5"
SD
FE
12" 16-36" SD
OPEN
48"
SD
OPEN
36"
12" CLOSED
4"
8" CLOSED
1"
6" CLOSED
.5"
2"
SD
FE
2.5"
4"
so
FE
2"
6''
2"
6" CLOSED
.5"
12" CLOSED
18"
D
OPEN
36"
D
OPEN
2-6" 6'' 3" 2-18' ' 2" 3"
3" 60'' 6'' 6-24" 2" 18"
D
CLOSED CLOSED
SD
OPEN OPEN
8"
18"
D
OPEN
12"
SD
OPEN
10''
8"
0
OPEN
2"
48" CLOSED
2-4"
3"
so
OPEN
6'' CLOSED
12"
36''
1"
24"
1"
6''
5-1 "
5"
0
OPEN
so
OPEN
so
FE
so
OPEN
24"
18"
60''
1"
12"
48"
6''
10''
so
so
FE
so
OPEN
so
OPEN
so
MN,FE
21
Map Sta 132 133 133 133 133 133 133 134 134 134 134 134 134 134 134 134 135 136 136 136 136 136 136 137 137 137 138 139 139 139 139 139 139 140 141 142 142 142 142 143 143 144 144 145 145 145 146 147 148 148 149 150 151 151 152 152 152 153 153 154 154 154 154 154 154 154 154 154 155 156
Eastlng 1710 1670 1670 1670 1670 1675 1675 1675 1675 1675 1675 1675 1675 1675 1675 1675 1670 1675 1675 1675 1675 1675 1675 1665 1665 1665 1630 1890 1890 1890 1890 1890 1890 1850 1840 1835 1835 1835 1835 1830 1830 1845 1845 1885 1885 1885 1895 1210 1095 1095 1000 600 575 575 500 500 500 220 220 65 65 65 65 65 65 65 65 65 100 210
Southlng Rx Typ
875 BQFG
930
OTE
930
OTE
930
OTE
930
OTE
940
OTE
940
OTE
965 GOMS
965 GOMS
965 GOMS
965 GOMS
965
OTE
965
OTE
965
OTE
965
OTE
965
VO
980
OTE
1010 OTE
1010 OTE
1010 OTE
1010 OTE
1010 OTE
1010 OTE
1030 BQFG
1030 BQFG
1030 BOFG
1140 BOFG
1040 GOMS
1040 OTE
1040 OTE
1040 OTE
1040 OTE
1040 OTE
1030 SSG
1005 OMS
1005 OTE
1005 OTE
1005 OTE
1005 OTE
970
OTE
970
OTE
940 SBOFG
940 SBOE'G
890 AMPH
890
SSG
890
SSG
850 SBQFG
855
SSG
1410 BQFG
1410 BOFG
1335 AMPH
1150 OTE
1145 OTE
1145 OTE
1115 SBQFG
1115 SBQFG
1115 SBQFG
1000 BQFG
1000 BOFG
1340 BOFG
1340 BOFG
1340 OMS
1340 OTE
1340 OTE
1340 OTE
1340 OTE
1340 OTE
1340 SSG
1480 GBQFG
1350 SSG
Fol Trend
N72W N84W N50W
N67W N58W N40W N52W
N64E N85W NBOW N90E NBOE N88W NBOE N85E
N81E N65E N75E
N69W N37W N50E NBOW
N67W
N69W
N43E N68E N82E N67W N70W N12E N15W
N40E N65E
N40W
N74W N85E N78W N75E N56W NBOE N76E
N72W N40E N76E
FoiDip
32NE 35NE 27NE
43NE 33NE 29NE 29NE
56NW 18NE 14NE 60N 24NW 29NE 21NW 13NW
34NW 16NW 21NW
12NE 20NE 9NW 20NE
23NE
28NE
77NW 23SE 25SE 23NE 65NE 44NW 40SW
34SE 55NW
27NE
26NE 35NW 50NE 32NW 53NE 44NW 47NW
33NE 30NW 53NW
FAULT FOLD
Trend Dip Plunge
N65W N25E N90E N20W
51SW 64SE 71S 85NE
N8E N14W N88E N35W N90E N50E N45W N15E N70E N45W
88SE 67NE 40NW 45NE 70S 64SE 70SW 88SE BONW
11NW
N63W N55W N87E N47E N10W N30E N5W N60E N30W N18W
78SW 37SW 60SE 45SE 88NE BOSE 79SW 70NW 85NE BOSW
N40W N30E N10W N90E N65E
83SW BOSE 85SW 75N 89SE
N60W N55E N40W N25E N65W N40W N65W N67E
77SW 88NW 75NE 74NW 75SW
90E 83SW 77SE
N70W 89NE N10E BONW
N27W N20E N8E N30E N89E N80W N30W
80SW 64SE 82NW 87NW 59SE SBNE 58SW
N27W N90E N60E NOW N15W N4E
77NE 70S 44SE 70E 85NE 77SE
Joints Space Persist Dllal
Weath.
2-4" 12-36''
D
OPEN
2"
48"
SD
1-2" 4-6''
SD
FE
111
3" CLOSED
12"
192"
D
OPEN
12-120" 96"
D
FE
12"
60"
D
FE
12-36" 96"
D O,FE,OPE
1"
SH CLOSED
8"
16" CLOSED
3"
24'' CLOSED
12-36" 12"
2" 1" 25-1" 12"
6"
36" 36" 60" 48" 24-36" 12" 48" 10" 6'' 12"
SO
FE
D
MN
D
MN,VQ
SD
MN,FE
D
FE,MN
SD MN,OPEN
SD
CLOSED
D
FE
D
FE,OPEN
1" .5-1"
1"
1-2" 4"
4"
D
MN
12" CLOSED
8"
SD
FE
2-3" CLOSED
16"
D
FE, OPEN
1"
4-6" CLOSED
12"
12"
D
FE
3" 36-48"
D
OPEN
2''
6" CLOSED
6''
12"
D
OPEN
.5"
12"
D
OPEN
1"
12"
D
FE
1.5"
6''
SD
FE
12"
36"
D
FE
1"
24"
D
FE
,5-1 " 3-8"
48"
4" CLOSED
12-18"
D
MN,FE
5" .5-2"
12" CLOSED 18"
3" 3" .51"
1(}.12" 24" 8-12"
18" 2-3" 4" 24" 36-48" 4'
so
SD
D CLOSED CLOSED
FE FE
OPEN
22
Joints
Map Sta Eastlng Southlng Rx Typ Fol Tntnd Fol Dip
Tntnd Dip Plunge Space Persist Dllat. Weath.
157
285
1300 SBQFG N76E
27NW
N10E 76NW
6"
24" CLOSED
157
285
1300 SBQFG N90E
35N
157
285
1300 SBOFG N67W
29NE
N76E 39SE N25E 77SE
.5-1 "
812" CLOSED 2" CLOSED
157
285
1300 SBOFG N80W
18NE
157
285
1300 SBOFG N76E
46NW
157
285
1300 SBOFG N82W
31NE
158
335
1615 BOFG N70W
37NE
159
50
1995 SSG
N10W
18NE
159
50
1995 SSG
160
30
2230 SBQFG N40E
32SE
160
30
2230 SBOFG
160
30
2230 SBOFG
160
30
2230 SBOFG
N84W N65E N15W N40E N20W N90E N60E
37NE 65NW 64SW 36SE 70SW
70S 65NW
.5"
3"
so
FE
.5"
.5"
SD
4"
1"
18"
12''
D
OPEN
12"
12"
D
OPEN
160
30
2230 SBQFG
N55W 70SW
161
330
2180 BOFG N45E
34SE
162
1015
2230 GBQFG N65W
4NE
N90E 90W
163
600
1095 SBOFG N58E
50SE
163
600
1095 SBOFG
163
600
1095 SBOFG
N5W BSNE NOE 75W N25W 90E
36'' 48-72" 8"
163
600
1095 SBOFG
NJSE 80NW
163
600
1095 SBQFG
N75W 85SW
164
1215
1750 SSG
N74W
63SW
165
1240
1840 GBOFG
N23E 75SE
165
1240
1840 GBOFG
N61W 68NE
165
1240
1840 GBQFG
N34E 7NW
165
1240
1840 OMS
N25W
21NE
165
1240
1840 OMS
N62W
31NE
165
1240
1840 OMS
N30W
6NE
N84E 90W
166
1260
1860 OMS
NJSW
29NE
N80E 90W
167
1300
1945 GBOFG N20W
30NE
N82W 33fNV
167
1300
1945 GBOFG N30W
25NE
N25E 60NW
168
1290
2225 GBOFG N58E
33SE
168
1290
2225 GBOFG N42E
30SE
168
1290
2225 GBOFG N68E
49SE
169
1175
2000 BOFG N72W
19NE
N8E 85NW
2-7"
8"
169
1175
2000 BOFG
N50W 87NE
169
1175
2225 BQFG
170
1440
1635 GBOFG N25W
4NE
170
1440
1635 GBOFG
171
1525
2045 GBQFG N18W
33NE
171
1525
2045 GBOFG
N18W N84W N20E N21E N42W
17NE 83SW 75SE BSNW f!IJSW
810"
6"
D
24-36"
5"
12"
D
18"
24"
D
OPEN
OPEN OPEN
171
1525
2045 GBQFG
N70E 67NW
171
1525
2045 GBQFG
N21W 85SW
172
1520
2070 GBOFG N40W
23NE
173
1325
2030
SSG
N50E
4BSE
173
1325
2030 SSG
N80E 63NW N40W 72fNV
.5-1 " 10"
so
OPEN
1"
4-6"
D
OPEN
173
1325
2030 SSG
VQ
NOW 36E
2-5"
96"
174
1555
2070 SSG
N40W
40NE
175
1570
1685 BQFG N30W
65NE
176
1770
1860
SSG
N46E
43SE
N19E 83SE
36'' CLOSED
176
1770
1860 SSG
NJSE
40SE
N60W 82SW
12"
2-6'' CLOSED
176
1770
1860 SSG
N60E SONW
177
1640
1470 BOFG N78W
26NE
178
1850
1560 GBOFG N43W
44NE
179
1905
1595 OMS
N71W
64NE
N12W 85SW
179
1905
1595 OMS
N84E
JSNW
N55W 90E
180
1910
1745 BOFG N31W
43NE
181
1615
1285 FCR
N14E 88NW
4" CLOSED
181
1615
1285 FCR
N32W 59SW
181
1615
1285 FCR
N35E 41NW
182
1770
1285 GBOFG N62W
58NE
183
1920
1325 SSG
N50W
42NE
N60W 62SW
183
1920
1325 SSG
N16W 42SW
48"
D
FE
183
1920
1325 SSG
183
1920
1325 SSG
N40E 40NW NOE 39W
8"
36" CLOSED
6"
18"
D
OPEN
184
1815
1140 FCR
N10E
90W
N70W SOSW
184
1815
1140 FCR
N55W 78NE
118" 60" CLOSED
185
1885
1085 OTE
N78E
23SE
NOE 90W
.5"
36"
D
OPEN
185
1885
1085 OTE
N47E
28SE
N68W B6SW
2"
6"
D
OPEN
185
1885
1085 OTE
N30W 71SW
3"
5"
D
OPEN
23
Map Sta
186 186 187 187 187 188 189 1SO 191 192 193 193 194 195 195 196 197 197 198 199 200 201 202 203 204 204 204 204 205 206 206 207 207 207 207 208 208 208 209 209 210 211 211 212 213 213 213 213 213 214 214 214 215 215 216 216 217 217 218 218 219 219 220 221 222 222 222 223 224 224
Eastlng
1885 1885 1900 1900 1900 1900 1905 1835 1910 1215 1180 1180 1715 1600 1600 1595
1395
1395
905
1100 1400 1215 1150 715 670 670 670 670 850 1250 1250 1255 1255 1255 1255 1240 1240 1240 1365 1365 1385 1375 1375 1410 1000 1000 1000 1000 1000
960
960
960
930 930 920 920 920 920 915 915 1055 1055 1035 1065 1070 1070 1070 1080 1080 1080
Southlng RxTyp
1100 QTE 1100 QTE 1140 GQMS 1140 GQMS 1140 GQMS 1110 GQMS 1065 QTE 990 GSS 835 GBQFG 855 SSG
815 GSS 815 GSS 435 BQFG 510 QMS 510 QMS 560 BQFG 1115 BQFG 1115 BQFG 315 BQFG 1285 FCR 1510 GBQFG 1215 BQFG 1145 BQFG 1060 SSG 1025 SBQFG 1025 SBQFG 1025 SBQFG 1025 SBQFG 825 GSS 770 SSG 770 SSG 755 SSG 755 SSG 755 SSG 755 SSG 780 SSG 780 SSG 780 SSG 740 SSG 740 SSG 1015 SBQFG 945 GBQFG 945 GBQFG 980 QTE
1015 SSG 1015 SSG 1015 SSG 1015 SSG 1015 SSG 1025 QTE 1025 QTE 1025 SBQFG 1035 QTE 1035 QTE 1040 SBQFG 1040 SSG 1040 QTE 1040 QTE 1040 SBQFG 1040 SSG 995 GBQFG
995 SSG 950 QTE 935 GKQMS 930 QTE 930 QTE 930 QTE 930 GKQMS
950 FCR 950 FCR
Fol Trand
N85W N68W N15W N65E NSOE N85W N58W
N56E N86W N27E
N35E
N8E N84W N60E
N10E
N70W N45E N20E N60E N70E
N72W N85W
N78E
N50E N60E
N88E
N75E N60W
N79E N40W N13E N82E
N75W NBOE N85W N49E
N40E N35E N64E
N70E N48E N45E N58E N85E NBOW N85W
NBOW N75W
Fol Dip
36NE 21NE
35SI/V
43NW 11N 23NE 69NE
28NW 32NE 28NW
30NW
23NW 29NE 15NW
BONW
54NE 28NW 41SE 46NW 44NW
79SI/V 23NE
59NW
23NW 30NW
66NW
26NW 12NE
32NW 2NE 27NW 37NW
40NE 35NW 51NE 20NW
4SE 43NW 29NW
27NW 38NW 30NW 35NW
60NW
45NE 35NE
30NE 60NE
Joints Trend Dip Plunga Spaca Persist Dllat.
Weatll.
NBOIN 87SI/V N5W 77NE
5" 2" 1"
D OPEN D OPEN
N12E 20SE NOW 62E N10W 87NE
N34E 56SE N10E 60SE
1"
1"
D
FE
.5-1" 10-12" D OPEN
N13E 79NW
12-24" 36-48" D OPEN
N25E 60SE N5E 71NW N40E 81SE N48W 75SI/V
N74E 89NW N10W 88NE N35E 76NW N35W 80SI/V N10E 84SE N15W 81NE N60W SOE
N55E sow
N15E 76SE N60E 18SE N50W 76NE N15E 62SE N55W SOE
N45E sow
FOLD
N70E 70NW
N60E sow
N70W BONE NOW SOE N85E N30E 85NW NSOE 65N
13SI/V
N25E 76SE N85E BOSE
1" 12"
D OPEN
1.5" 18"
D OPEN
.5" 6'' CLOSED
.5" 4-6" CLOSED
4" 12-18" D OPEN
12" 18"
D
OPEN
3" 40" CLOSED
.5-1" 12" CLOSED
CLOSED
1"
CLOSED
1.5" 1" 1" 12"
D OPEN D OPEN
1-3" 24-36" D OPEN
6''
2"
D OAL,OPE
1-2" >120" CLOSED 16" 4" CLOSED
1-6" >120" CLOSED 1-8" 1-6'' CLOSED
N20E 87NW
FOLD N20E
17NE
N20W 75NE N65E 56NW
N25W BOSI/V N40E 75SE N20W 60SI/V
NOE sow
N20W 71SI/V N70E 38SE
8" CLOSED MN 1" >48" CLOSED 8'' 12-24" CLOSED
36" CLOSED
24
Map Sta 225 225 226 226 227 227 228 228 228 228 229 230 231 232 233 233 233 234 235 236 236 237 237 237 238 238 239 239 240 241 242 243 243 243 244 244 244 244 244 244 244 245 245 245 245 246 247 247 247 248 248 249 249 249 250 250 250 250 250 250 250 250 251 252 252 252 252 252 253 254
Eastlng 1160 1160 1145 1145 895 895 985 985 985 985 875 825 805 1175 1160 1160 1160 1135 1150 1125 1125 1160 1160 1160 1670 1670 1635 1635 1595 1595 1540 1550 1550 1550 1220 1220 1220 1220 1220 1220 1220 1190 1190 1190 1190 1200 1230 1230 1230 1150 1150 1300 1300 1300 1435 1435 1435 1435 1435 1435 1435 1435 1550 1735 1735 1735 1735 1735 240 1005
Southlng Rx Typ Fol Trend
995
QTE
NBOW
995
QTE
990 TEIFC NBOW
990 TEIFCR
1045 OTE
N84E
1045 QTE
N70E
1025 QTE
N85W
1025 OTE
1025 SBQFG
1025 SBOFG
1055 SBQFG N64E
1070 GBQFG N79E
1065 SBQFG N55E
905
FCR
N75E
915
SSG
N85E
915
SSG
915
SSG
915
FCR
N74E
910
SSG
N62E
920
FCR
N69E
920
FCR
900
QTE
N82E
900
QTE
900
QTE
925 GOMS N85E
925 SBOFG N85E
945
QTE
N64W
945
QTE
N50E
970
QTE
N73E
1010 OTE
N90E
1020 GQMS N90E
1015 OTE
N88E
1015 QTE
1015 QTE
1000 QTE
N40E
1000 SBQFG N70E
1000 SBQFG
1000 SBOFG N75W
1000 SBQFG
1000 SSG
N90W
1000 SSG
N65E
975
QTE
N75W
975
OTE
975
QTE
975
SSG
N74W
995 GBQFG N75E
980
QTE
N75E
980
QTE
N70E
980
QTE
N77E
975
QTE
N70W
975
QTE
990
QTE
N88W
990
QTE
990
QTE
995
FCR
995
OTE
N30W
995
QTE
995
QTE
995
QTE
995
OTE
N70W
995
OTE
NOE
995
OTE
975
OTE
N84E
1050 QTE
N45W
1050 QTE
N55W
1050 QTE
1050 OTE
1050 SBQFG N60W
1285 QTE
950
SSG
N63E
Fol Dip 37NE
19NE
42NW 46NW 26NE
42NW 41NW 50NW 62NW 48NW
48NW 37NW 44NW
36NW
82NW 40NW 21NE 30NW 44NW
21N 32N 37NW
54NW 37NW
32NE
22N 52NW 52NE
55NE 38NW 25NW 18NW 27NW 41NE
30NE
18SW
31NE BOW
26NW 44NE 30NE
37NE
60NW
FOLD FAULT
Trend N50W N45E N5W N45E
Dip 75SW 82NW 75SW 77NW
Plunge
NrNV N60W N85E N25W
90E 75NE 60SE 70NE
N5W 85NE N26E 49SE NBOW 36SW
N30W 71SW
N34E 86NW
N36E 85SE
N87W 50SW
N2fNV 75SW
N90E
30E
N10E N38W N42E N80W
82SE 88NE 61SE 70SW
N55W NOE N35E N60E
67NE 87W 77SE 75NW
N55E 75SE N85W 80SW N55W 80SW
N30E N60E N45W N30W N60E N60E N50W N10E N80E N20E N85W N60E N30W N65E
90NW 84SE BONE 45SW 65SE 77SE 68SW 85NW 70NW 86NW 89NE 85NW 83NE 82SE
N82W 72SW
N30E N60W N10E N90W
87NW 83SW 85NW 89S
Joints Space Persist
4-6"
Dllal
12"
8"
D
4" 96-108"
1-4" 4" 1-2"' 1"
12" 4" 24-36'' 12"
D
CLOSED CLOSED
12" 8-12"
48" CLOSED 36" CLOSED
7" 6"
8-10"
14"
CLOSED CLOSED 24"
6''
4-6"
D
4-8" 12-18"
D
1-4" 12-18"
D
3"
8"
D
1"
36''
D
4" 6-12" 4-6"
24-36" CLOSED 18" CLOSED 12" CLOSED
2" 4-24" 1-2" 12" 6-8"
4" 3-4"
1"
18-24" 24-36"
8" 24" 12" 48-60" 8" 12-24"
CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED CLOSED
1" 36-48"
D
2"
36''
D
4"
12"
D
Weath. OPEN OPEN
FE OPEN OPEN
MN OPEN
KAOL OPEN
MN
25
Map Sta 255 256 256 257 257 257 257 257 258 258 258 259 259 260 261 261 262 262 263 263 263 264 265 266 267 268 269 270 271 272 273 273 274 275 276 277 278 279 279 279 279 280 281 281 282 282 283 284 285 286 287 288 289 290 290 290 291 291 291 291 292 293 293 294 294 295 296 297 298 298
Eastlng 995 995 995 990 990 990 990 990 980 980 980 950 950 935 920 920 895 895 885 885 885 870 840 920 940 995 1025 1050 1045 1080 1110 1110 1140 1190 1170 1055 1230 1250 1250 1250 1250 1265 1280 1280 1300 1300 1310 1315 1320 1325 1335 1430 1430 1405 1405 1405 1400 1400 1400 1400 1510 1520 1520 1650 1650 1645
Southlng Rx Typ Fol Trend
955 GKQMS N75E
960
QTE
N67E
960
QTE
955 GKQMS N90W
955 GKQMS N65E
955 GKQMS
955
QTE
N90W
955
QTE
N65E
965
QTE
N80E
965
QTE
N85E
965
OTE
N80E
970 GKQMS N70E
970 GKQMS N90E
975
QTE
N85E
985
BQFG
N55E
965 TEIFC N40E
990 TEIFC N85E
990 TEIFC N50E
995 CRIQT N75E
995 CR/QTE
995 CRIQTE
1000 CRIQT N70E
1015 OMS
N37E
975 CR/QT N60E
970 SBQFG N70E
950
SSG
N64E
945
QTE
N74E
940 GKQMS N54E
930
FCR
N80E
930 CRIQT N75W
910
BQFG
N30E
910 BQFG
900
FCR
N82W
890
QTE
905
TEIFC
N80E
945 GKQMS N65E
905
QTE
N80E
905
QTE
N86W
905
QTE
905
QTE
905
QTE
N86E
900 TEIFC N78E
910
QTE
N60E
910
QTE
N85E
910 GKQMS N90E
910
QTE
N80W
910
QTE
N90W
910 SBQFG N75E
910
QTE
N80W
910
QTE
N65W
915 SBQFG N60W
920
SSG
N65E
945 BQFG
N5E
900
QTE
N75E
900
QTE
900
QTE
910 GBQFG N80E
910 GBQFG N55W
910 GBQFG N90W
910
QTE
N70E
620
BQFG
N22E
835
OTE
N60E
835
QTE
760 GBQFG N74E
760
QTE
N85W
770 BQFG N35W
1580 1650 1650
625
SSG
N67W
BOO GBQFG N80E
BOO GBQFG
Fol Dip 40NW 36NW
45N 71NW
BON 37NW 66NW 50NW 40NW 63NW
47N 46NW 48NW 46NW 69NW 46NW 60NW
56NW 35NW 37NW 35NW 27NW 42NW 46NW 45NW 50NE 45NW
60NE
62NW 76NW 48NW 85NE
76SE 59NW 90W 90W
49N 90E 49N 41NW 45NE 74NE 50NE 25NW 49SE 27NW
44NW 38NE 45N 32NW 25NW 18NW
35NW 25NE 38NE
44NE 25NW
Joints Trend Dip Plunge Space Persist Dllat
Weath.
NOE N80E N2E N40E N70W N5W N45W N1W N65W N5W
85W 72SE 35SE 51SE 90E BONE 30SW 90E 52SW 74NE
2"
12'' CLOSED
.5" 6-12" CLOSED
12"
36" CLOSED
1"
12" CLOSED
1-3"
48"
D
OPEN
12"
D
MN,FE
25" 25-1"
4" CLOSED 4" CLOSED
N40E 83SE
2-4"
24" CLOSED
N15E 83SE N5W 75NE N70E 81NW
1" 12-18" CLOSED
1-2"
24"
0
OPEN
2"
NOW 90E N90W 88S
N50W N15E N5W N75E N50W
40SW 60SE 62SW 35NW 68NE
1"
12"
5"
D
OPEN
D
OPEN
2-4" 6-18"
.5" 4"
12" 6" 12-24" 24-36"
D CLOSED CLOSED CLOSED
SI02
N30E 80NW
N85E N40W N10E N5E N30W N30E N82E
65SE 67NE 86NW 84NW 90E 88NW 88NW
N25E BOSE NBOW 86NE
N55E 87SE
N45W 82NE N80E 75SE
12"
46" CLOSED
.5"
2-4" 24" 3-12" 1-2"
12"
48-60'' 36'' 120''
>120"
SD
D 0
CLOSED CLOSED CLOSED CLOSED
OPEN OPEN OPEN
4" 36-48" CLOSED
4"
36" CLOSED
2"
36" CLOSED
4"
>12" CLOSED
1"
46" CLOSED
26
Map Sta
298 298 299
300
301 302 278 1198 1338 1548 1668 1728 2088 2208 2209 2209
Eastlng
1650 1650 1650 1655 1680 1725 50 1660 1670 1320 1280 1425 1315 1035 1035 1035
Southlng Rx Typ
800 GBOFG 800 SSG 785 BOFG 765 QTE 745 OTE 740 QTE 0 GSS 815 OMS 925 QTE 90 BOFG 1890 8QFG 2070 BOFG 740 GBOFG 945 QTE 945 QTE 945 QTE
Fol Trend
N62W N45E N45W NB4W N5E N56E
N65E N46E
FoiDip
2BNE 35NW 31NE 55NE 85SE 45NW
50NW 51NW
Trend Dip
N10E 9fNI
Plunge
Joints Space Persist Dllat.
1" 48-60" CLOSED
Waath.
N20E 80NW N75E 70NW N40E 30SE
4-6'' 12-24" CLOSED .5" 4-6'' CLOSED 4" 10-12" CLOSED MN
27
DEPARTMENT OF NATURAL RESOURCES ENVIRONMENTAL PROTECTION DIVISION GEORGIA GEOLOGIC SURVEY
INFORMATION CIRCULAR 98 PLATE 1
GEOLOGIC
UNITED STATES DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
MAP
OF
THE
BARNESVILLE HYDROGEOLOGIC
STATE OF GEORGIA
DEPARTME NT OF NATURAL RESOURCES GEOLOGIC AN D WATER RESOURCES DI VI SION
RESEARCH SITE.
BARNESVILLE QUADRANGLE
GE ORG I A 7.5 MINUTE SERI ES (TOPOGRAPHIC)
SW/4 BA RNESVl LL 15 QUAORAN G! E
LAMAR
COUNTY.
GEORGIA
{ ]'
/
~ /
I
EXPLANATION (no stratigraphic order implied)
Units north of the Towaliga Fault Zone ~ Graphite-quartz-muscovite-sillimanite schist with interlayers ofporphyroclastic ~ biotite-quartz-feldspar gneiss.
r::=--, Sheared graphite-quartz-muscovite-sillimanite schist and chlorite-quartz-
~ muscovite schist with infolded biotite-quartz-feldspar gneiss and isolated pods of quartz-garnet granofels. Abundant quartz sillimanite veins concordant and discordant to foliation.
~ Intercalated gondite, biotite gneiss, amphibolite and sillimanite-quartz~ muscovite schist. ~ Porphyroclastic and granitic biotite-quartz-feldspar gneiss with local ~ discontinuous interlayers of amphibolite and quartz-muscovite schist
sillimanite.
r::::::1 Migmitized porphyroclastic and granitic biotite-quartz-feldspar gneiss with
~ local discontinuous layers of quartz-muscovite schist sillimanite.
Units within and south of the Towaliga Fault Zone
~ Feldspathic, micaceous quartzite, locally mylonitic.
E J Sheared biotite-feldspar-quartz-muscovite schist kyanite garnet.
~ Sheared, silicified garnet-muscovite-biotite-quartz-feldspar gneiss, ranging ~ from augen gneiss to blasto- and ultramylonite.
~ Cataclasite, flinty crush rock.
Units south of the Towaliga Fault Zone ~ Garnetiferous muscovite-biotite-quartz-feldspar gneiss with local interlayers ~ of quartz-muscovite schist, sheared schist and lenses of cataclasite.
~ Cataclasite, flinty crush rock.
Strike and dip of foliation
, _ Trend and plunge of lineation
Trend, plunge and dip of axial plane of minor folds
Contact
Approximate contact
Inferred thrust fault
Towaliga Fault
Mapped ed1ted and publ1shed by t he Geolog1cal Survey
Control by USGS NOS/NOAA and Georg a Godet1c Survelo
Topog raphy by p hotogrammetr1c met hod s f om aer1al ohotogra ph s t ;J ken 19 7 3 F1e1d checked 197 3
PrO I" tfo n 2nd 10 000 foo t gnd t ck C.eo g ~::l coo dm ate
~ystE: m .,.~~ t zo1~> ' tr a J'S>Brs e Mt Ca'o1, Qr ](' l e>r<> Jj \1\fersa l T 1~n , ~ " '"e "il C'\ illur g'd ' <. k$
10 < 6 snovm n btl,e 19 2 7 '~ onh Af "'"a" dawno
Ftn < f!.-d rlash ed ltne~ mdJc ch: selec so te'l ce ana ft e o I nes wl ere gent rall y v o 1b eon aena l pho tog~a phs h 1s mformat1on 1s. uncheckeC P ea tlr'l' tndKates. <:~reas tn wh1c h or ly l and matH ou tld1ngs an;! sh own
~
W
"II
s
I
I
l "3
1 '7 r~ "
\'
UTiol Gft!D AND CJ ~ MAC Nt llC NORTH (, ECUN/11 ON A.f CPHH< ; F SHEn
I
E- -
4 149 I NW
~E~ -
SCALE 1 24 000
~
0
::::c-.::=E~ 3_..:-..E"' - 3:~
- "'"--~-====
--=- ,QOO
0
1000
2000
3000
a::::EC:E ;r:::___----=::;:;.:.=---====:1-- - f -
4000
5000
::r==: - ---'- -
61)00
E "'L ~J :f " 3-::--r--c"r::- ~ -::0::r=
r (,N ro 1 ~ I NTE RVAl 10 fEET
Nllll fJ"At FCI J~1 1C Vi f, TI C AL 'l' f U '-1 G F 19~9
7000 FEET
I MILE
TH IS MAP COM PI I [~ WI TH NATIONAL MAP ACCUR ACY STANDARDS FOR SALE BY U S G01 OG!CAL SURVEY RESTON VI RGINIA 22092 A FOLDER DESCRIBING TOPOSRAPrHr: MAPS AN D SYMBOLS IS AVAILABLE ON REQUEST
"'-, ,-
. '
'
> { G' OH, A
--J
QUAD RANGL! LOC ~ TIO N
ROAD CLASSIFICATION
Pnmary h1ghway hard surface
L1ght duty road hard or Hnp rov ed su rface -===---= =-
Secon d a r ~h1g h way
nard surface
-.. --= =-- unm pr ov ed road
G 0 c~ In ers tal e Route
u s Route
Stat<> Ro ~.m
BARNES VILLE, GA
SW 4 B ~ RN:SV IL L E S QUADRAIK.LE.
N3300 ~ W8407 517 5
1973
AM'> 4 150 ll SW SERIES V8 45
N
Study
/Area
GEORGIA
DEPARTMENT OF NATURAL RESOURCES ENVIRONMENTAL PROTECTION DIVISION GEORGIA GEOLOGIC SURVEY
JOINT SET MAP BARNESVILLE HYDROGEOLOGIC RESEARCH SITE
LAMAR COUNTY. GEORGIA
INFORMATION CIRCULAR 98 PLATE 2
UNITED STATES DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
27
Strike and d1p of j01nt
Strike and dip of vert1cal JOint
Rose diagrams summanz1ng strike of JOint sets for a given area
0'-----~~2
n=11
STATE OF GEORGIA
DEPARTMENT OF NATURAL RESOURCES GEOLOGIC AND WATER RESOURCES DIVISION
BARNESVILLE QUADRANGLE
GEORGIA 7 5 MINUTE SERIES (TOPOGRAPHIC)
SW/4 BARNESVILLE 15 QUADRANGlE
Mapped ed1led and publiShed by the Geolog1cal Survey
Control by USGS NOS/NOAA, and Georg1a Geodet1c Survey
Topography by photogrammetr1c methods from aenal photographs taken 1973 Fteld checked 1973
PrOJPt:t ton and 10,000 foot gnd ttcks Georgia coordmate system west zone (transverse Mercator)
1000 metre Umversal Transver se Mercator gnd t1cks
zone 16 shown 1n blue 1927 North Amencan datum
F1ne red dashed lmes 1nd1cate selected lence and f1eld lmes where generally vts1ble on aenal photographs Th1s mforrnatton 1s unchecked
Red tnt 1nd1cates areas tn whtch only land mark buddtngs are shown
*
UTM GRID MW 1973 MAGNETIC NORTH DECLINATION AT CENTER OF SHEET
I
41'>9 I NW
SCALE I 24 000
MILE
CONTOUR INTERVAL 10 FEET NATIONAL GEODETIC VERTICAL DATUM OF 1929
KILOMETR[
THIS MAP COMPUES WITH NATIONAL MAP ACCURACY STANDARDS FOR SALE BY U S GEOLOGICAl SURVEY RESTON VIRGINtA 22092 A FOLDER DESCRIBING TOPOGRAPHIC MAPS AND SYMBOLS IS AVAILABLE ON REQUEST
~ ~EOilGIA
'"-- -,J...j
QUADRANGLE LOCATION
'67
ROAD CLASSIFICATION
Pnmary htghway hard surface
Ltght duty road hard or
Improved surface
Secondary htghway
ha rd surface
-=~,_. Un1rnpto-1ed road
0 Q Q Interstate Route
U S Route
State Route
BARNESVILLE, GA.
SW/4 BARNESVILLE 15 QUADRANGLE
N3300 -W8407 5/7 5
1973
AMS 4150 II SW- SERJES 845
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