4

8

4 4

8

8

8

4

4

8

4

4

5

4

5

4

81

55

83

72

81

141886

79

84

87

80

54

86

89

38

39

81

77

88

8381

84

78

71

86

66

8671

81

38

5474

8688

84

79

71

84

66

81

88

88

886682

86

84

72

8430

59

86

60

74

14

64

86

89

56

8885

74

14

76

85

7981

6365

75

73

78

77

7688

89

68

74

86

7156

85

87

67

83

75

89

8787

80

76

66

82

84

88 88

47

88

80

78

57

85

80

84

8750 81

71

858482

8662

65 6062

81

8584

88

79

46

74

82

75

88

79

82

76

77

806681

81

8576

79

80

7586

86

8652 66

78

88

74

87

88

82

87

74

88

86

54

69 82

8188

66

71

7879

83 65

8089

72 73

74

80

8178

74

68

8871

5681

6455

87

828859

86

8684

75

62

74

34

82

8685

7879

75

7469

8681

8484787478

6884

87

6666

88

85

84

87

75

8277

88

80

8486

75

30

44

706674

60

70

76

10

7240

60

54

6676

74

54

888082

78

84 82

70

68

88

607276

60

84

87

84

8880

85

46

76 72

80

8072

70

7675

68

68

8883

80 74

11

19

5084

7150

6156 74

45

84

7984

698185

4274

71

72

72

71

65

81

85

8350

80

86

82

80

4169

8280

85

8373

82

78

7065

86

64

66

88

64

5960

88

5284

80

8952 60

65

60

88

7460

8911

8986 6072

79 75

87

88

80

58

7585

60

85

8176

88

34

86

84

8284

65

61

77

80

8881

88

88

80

86

84

88

21

60

8884

59

79

1946

8684

82

6174

87

84

81

74

75

31

77 3085

16

7288

82

72

5985

86

85

50

79

8282

28

84

82

89

698879

87

81

7148

84

88

8461

81

6972

89

67

86

88

83

8078

61

88

74

88

77

58 74

56

65

88

8160

8850 67

84

67

79

85

81

74

7889

71

68

7125

77

6879

8889

5467

81

70

807989

7378

6968

85 72

67

88

86

74

8870

488985

74

8286

84

73

88

77

75

84

88

8879 8474

74

88

20

7866

80

8468

8480 58

705646

7614

82

10

73

2260

6476

1078

70

2035

10

62

6258

305256

86

58

7680

80

60

828616

86

23

88

70

8616

63

3058

28

7070

66

80

85

78

8614

7686

6882

71

79

25

76

6976

68

30

81

5881

74

75

47

61

80

20

7068

82

8087

84 40

83

86

45

21

89

87

54 80

65

Qal

K/Tu

Qal

K/Tu

K/Tu

K/Tu K/Tu

K/Tu

K/Tu

K/Tu

K/Tu

K/Tu

Qal

Qal

K/Tu

K/Tu

K/Tu

Qal

Trcs/si2

Zhe/pl

Zhdlt (u)

Zhadlt (u)

Trp

Zhe/pl

Zhe/pl

Zhablt

Zhe/pl

Zhe/pl

Trp

Trpc

Zhe/pl

Trp

Zhadlt (u)

Trcc

Zhe/pl

Zhdlt (u)

Trpc

Zhadlt (u)Trcc

Zhe/pl

Trpc

Zhadlt (u)

Trcc

Zhe/pl

Zhe/pl

Trpc

UD

UD

DU

DU

U

DU

D

Qal

Zhablt

Zhablt

Zhablt

Zhe/pl

Zhe/pl Zhadlt (u)

Zhadlt (u)

Zhadlt (u)

Zhe/pl

Zhe/pl

Trcs/si2

Zhe/pl

Zhe/pl

Zhdlt (u)

Zhdlt (u)

Zhdlt (u)

Zhdlt (u)

Trcs/si2

Zhe/pl

Trcs/si2

Zhe/pl

Zhe/pl

Zhe/pl

TrpZhe/pl

Trp

Trpc

Zhe/pl

Zhe/pl

Zhdlt (u)

Zhdlt (u)

Zhdlt (u)

Zhdlt (u)

Zhdlt (u)

A

A'

B

B'

BONSA

L-MORRIS

VILLE

FAULT

Qal

CHATHAM COUNTYLEE COUNTY

Th is g e olog ic m ap was fu nded in part by th e USGS Nationa l Coope rative Ge olog ic Mapping Prog ra m

DEPAR TMENT OF ENVIR ONMENT AND NATUR AL R ESOUR CESDIVISION OF ENER GY, MINER AL, AND LAND R ESOUR CESTR ACY E. DAVIS, DIR ECTORKENNETH B. TAYLOR , STATE GEOLOGIST

NOR TH CAR OLINA GEOLOGICAL SUR VEYOPEN FILE R EPOR T 2012-02

79 00' 00"35 45' 00"

35 37' 30"79 07' 30"

35 37' 30"79 00' 00"

Disclaimer:T his Open-File report is preliminary and has been review ed for conformity with

the North Carolina Geological S urvey editorial standards or with the North AmericanS tratigraphic Code. Further revisions or corrections to this preliminary map may

occur prior to its release as a North Carolina Geological S urvey map.

Base map is from USGS 2010 GeoPDF of the Merry Oak s 7.5-minute quadrangle.Aerial photo, map collar and select features removed. Bounds of GeoPDF based on 7.5-minute

grid projection in UT M 17S; North American Datum of 1983 (NAD83).

T his geologic map w as funded in part by the USGS National CooperativeGeologic Mapping Program, aw ard number G11AC20296.

T he views and conclusions contained in this document are those of theauthors and should not be interpreted as necessarily representing theofficial policies, either expressed or implied, of the U.S. Government.

By Philip J. Bradley, Heather D. Hanna and Michael J. Malask aDigital representation by Michael A. Medina and Philip J. Bradley

2012(updated 3/2/2017)

GEOLOGIC MAP OF THE NOR THWEST POR TION OF THE MER R Y OAKS7.5-MINUTE QUADR ANGLE, CHATHAM AND LEE COUNTIES, NOR TH CAR OLINA

GEOLOGIC MAP OF THE NORTHW

EST PORTION OF THE MERRY OAKS 7.5-M

INUTE QUADRANGLE, CHATHAM AND LEE COUNTIES, NORTH CAROLINA

NCGS OPEN FILE REPORT 2012-02 (updated 3/2/2017)

Equal Area Schmidt Net Projection of Contoured Poles to PrimaryLayering, Bedding and Welding/Compaction Foliation of Carolina

Terrane Rocks (squares) and of Bedding to Triassic Sediments (circles with cross). Contour Interval = 1 N = 54

Equal Area Schmidt Net Projection ofContoured Poles to Foliation and Cleavage

Contour Interval = 1 N = 153

Unidirectional Rose Diagram of Joints N = 429

Outer Circle = 7.5%Mean direction = 22

Zhadlt (u) Trcs/si2Zhe/plZhablt

Zhadlt (u) Crystalline Basement

Zhe/pl

Zhadlt (u)Zhe/pl Zhe/pl

Trcc

Zhe/pl

Qal

-1,521'

-3,521'

0'479'

A A'

Zhadlt (u)

US HWY 64 Jordan Lake Bonsal - Morrisville Fault

Jd

JdJd

479'0'

-3,521'

-1,521'

Zhdlt (u)

Zhdlt (u)

Zhe/pl

No Data - UnmappedZhdlt (u)

Trp

Zhe/pl

Zhe/plTrp Zhe/pl

Zhe/pl

Trpc

Trpc

Trpc K/TuB B'

Zhdlt (u)Jd

Jd

403'0'

-1597'

-3597'

403'0'

-1597'

-3597'

Stinking CreekGum SpringsChurch Road Kirks Creek Arm

of Jordan LakeJordan

Dam Rd. US HWY 1

1 0 10.5Miles

1,000 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000500Feet

1 0 10.5Kilometers

SCALE 1:24 000

INT RODUCT IONPre-Mesozoic crystalline rock s in the Merry Oak s Quadrangle are part of the Virgilina sequence of the Neoproterozoic to Cambrian Carolina terrane of the Carolina Z one (Harris and Glover,1988; Hibbard et al., 2002; and Hibbard et al., 2006). In the region of the map area, the Virgilina sequence can be separated into two lithotectonic units: 1) the Hyco Formation and 2) theAaron Formation. T he Hyco Formation consists of ca. 615 to 633 Ma (W ortman et al., 2000; Bowman, 2010; Bradley and Miller, 2011) metamorphosed layered volcaniclastic rock s andplutonic rock s. Available age dates (W ortman et al., 2000; Bradley and Miller, 2011) indicate the Hyco Formation may be divided into lower (ca. 630 Ma) and upper (ca. 615 Ma) members(informal) with an apparent intervening hiatus of magmatism. In northeastern Chatham County, Hyco Formation units are intruded by the ca. 579 Ma (T adlock and Loewy, 2006) EastFarrington pluton and associated W est Farrington pluton. T he Aaron Formation (not present in the map area) consists of metamorphosed layered volcaniclastic rock s with youngest detritalzircons of ca. 578 and 588 Ma (S amson et al., 2001 and Pollock , 2007, respectively).T he Virgilina sequence was folded and subjected to low grade metamorphism during the ca. 578 to 554 Ma (Pollock, 2007) Virgilina deformation (Glover and S inha, 1973; Harris and Glover,1985; Harris and Glover, 1988; and Hibbard and S amson, 1995). In the map area, original layering of Virgilina sequence lithologies are interpreted to range from shallow ly to steeply dippingdue to open to isoclinal folds that are locally overturned to the southeast.

Map units of meta-volcaniclastic rock s include various lithologies that when grouped together are interpreted to indicate general environments of deposition (or lithofacies). T he dacitic lavasand tuffs unit is interpreted to represent dacitic domes and proximal pyroclastics. T he andesitic to basaltic lavas and tuffs unit is interpreted to represent eruption of intermediate to mafic lavaflows and associated pyroclastic deposits. T he epiclastic/pyroclastic units are interpreted to represent deposition from the erosion of dormant and active volcanic highlands. Meta-volcaniclasticunits within the map area display lithologic relationships similar to units present in northern Orange and Durham Counties. Due to these similarities, the meta-volcaniclastic units have beententatively assigned to the upper portions of the Hyco Formation; geochronologic data is needed to confirm this interpretation.T he eastern portion of the Chatham County is underlain by T riassic-aged sedimentary rock s of the Deep River Mesozoic basin which is separated into three sub-basins (Durham, S anford andW adesboro). T he Colon cross structure (Reinemund, 1955), located immediate southw est of the Merry Oak s Quadrangle, is a constriction zone in the basin characterized by crystalline rock soverprinted by complex brittle faulting. T he Colon cross-structure mark s the transition betw een the Durham and S anford sub-basins. T he Merry Oak s Quadrangle contains rock associated withboth the Chatham Group of the Durham sub-basin and the Pek in Formation of the S anford sub-basin. Dik es of Jurassic aged diabase intrude the T riassic sediments. Diabase dik es also intrudethe crystalline rock s of the map area. Quaternary aged alluvium is present in most major drainages.All pre-Mesozoic rock s in the map area have been metamorphosed to at least the chlorite zone of the greenschist metamorphic facies. Many of the rock s display a weak or strong metamorphicfoliation. Although subjected to metamorphism, the rock s retain relict igneous, pyroclastic, and sedimentary textures and structures that allow for the identification of protolith rock s. As such,the prefix “meta” is not included in the nomenclature of the pre-Mesozoic rock s described in the quadrangle. Jurassic diabase dik es are unmetamorphosed.

T he nomenclature of the International Union of Geological S ciences subcommission on igneous and volcanic rock s (IUGS) after Le Maitre (2002) is used in classification and naming of the units.T he classification and naming of the rock s is based on relict igneous textures, modal mineral assemblages, or normalized mineral assemblages when whole-rock geochemical data is available.Past work ers within the adjacent areas (Eligman, 1987 and W agener, 1964 and 1965) have used various nomenclature systems for the igneous rock s. T he raw data, when available, of these earlierwork ers was recalculated and plotted on ternary diagrams and classified based on IUGS nomenclature. Pyroclastic rock terminology follows that of Fisher and S chmink e (1984).

DESCRIPT ION OF MAP UNIT SSEDIMENTARY UNIT SQal – Allu viu m : Unconsolidated poorly sorted and stratified deposits of angular to subrounded clay, silt, sand and gravel- to cobble-sized clasts, in stream drainages.May include point bars, terraces and natural levees along larger stream floodplains. S tructural measurements depicted on the map within Qal represent outcrops ofcrystalline rock inliers surrounded by alluvium.K/Tu – Post-Ch ath a m Group undiffe re ntiated sedim ents: Y ellow ish-orange to brownish-yellow to yellow ish-gray, unconsolidated to friable unit that consists of distinctivesubrounded to well rounded granules, pebbles and small cobbles of white- to rose-colored quartz interlayered with clay, sandy-clay and clayey-sand. Lesser amounts ofmoderately indurated, yellow ish-white, medium- to coarse-grained ark osic sandstone present. Unit is mainly exposed on shores of B. Everett Jordan Lak e. Unit is inunconformable contact with T riassic sediments.Trcc - Cong lom e rate of th e Ch ath a m Grou p Lith ofacies Association III: Reddish-brown to dark brown, irregularly bedded, poorly sorted, cobble to boulder conglomerate.Clasts are chiefly miscellaneous felsic and intermediate metavolcanic rock s and quartz. T ypically present adjacent to border faults.Trcs/si2 - Sandstone with inte rb edded siltstone of th e Ch ath a m Group Lith ofacies Association II: Grayish-pink to pale-red, micaeous (typically white mica), coarse-to very coarse-grained, pebbly, cross-bedded lithic arkose interbedded w ith maroon, micaeous mudstone, burrowed and rooted siltstone. Bioturbation is usually surroundedby greenish-blue to gray reduction halos. Good outcrops typically exhibit cyclical fining upw ard depositional sequences. T hese rock s are assigned to the LithofaciesAssociation II of Hoffman and Gallagher, 1991 and W atson, 1998. T his unit has been extended into the Merry Oak s Quadrangle to edge-match with the FarringtonQuadrangle geologic map (Bradley et al., 2007) and the New Hill geologic map (Clark et al., 2004) .T he clastic rock s of Lithofacies Association II are interpreted to havebeen deposited in a meandering stream fluvial system.

Trpc – Cong lom e rate of th e Pe kin Form ation: Reddish-brown to dark brown to purplish-red, irregularly bedded, poorly sorted, cobble to boulder conglomerate. Clasts arechiefly miscellaneous felsic and intermediate metavolcanic rock s and quartz. T ypically present adjacent to border faults. Outcrops and boulders of float identified as part ofPek in Formation are strongly indurated compared to conglomerates identified as part of Chatham Group. Identified as the Pek in Formation-basal conglomerate byReinemund (1955).Trp – Pe kin Form ation: Gray, Brown to maroon, w hite mica bearing, interbedded mudstones, siltstones and ark osic sandstones. Outcrops and boulders of float identifiedas part of Pek in Formation are strongly indurated compared to conglomerates identified as part of Chatham Group. Identified as the Pek in Formation by Reinemund (1955).

INT RUSIVE AND METAINT RUSIVE UNIT SJd – Dia b ase: Black to greenish-black , fine- to medium-grained, dense, consists primarily of plagioclase, augite and may contain olivine. Occurs as dik es up to 100 ft wide.Diabase typically occurs as spheriodally weathered boulders with a grayish-brown weathering rind. Red station location indicates outcrop or boulders of diabase.METAVOLCANIC UNIT SHY CO FORMAT ION – UPPER PORT ION (S T RAT IGRAPHIC ORDER UNCERTAIN)

Zh e/pl - Mixed epiclastic-pyroclastic rocks with inte rlaye re d dacitic lavas: Grayish-green to greenish-gray, locally with distinctive reddish-gray or maroon to lavendercoloration; metamorphosed: conglomerate, conglomeratic sandstone, sandstone, siltstone and mudstone. Lithologies are locally bedded; locally tuffaceous with acryptocrystalline-lik e groundmass. S iltstones are locally phyllitic. Locally contain interbedded dacitic lavas identical to Z hdlt unit. Contains lesser amounts of fine- to coarsetuff and lapilli tuff with a cryptocrystalline-lik e groundmass. Minor andesitic to basaltic lavas and tuffs present. S ilicified and/or sericitized altered rock similar to Z hat unit arelocally present. Conglomerates and conglomeratic sandstones typically contain subrounded to angular clasts of dacite in a clastic matrix. Portions of the Z he/pl unit areinterpreted to have been deposited proximal to active volcanic centers represented by the Z hdlt unit but are also interpreted to record the erosion of proximal volcanic centersafter cessation of active volcanism.

Zh dlt (u) – Dacitic lavas and tu ffs of th e u ppe r portion of th e Hyco Form ation: Greenish-gray to dark gray, siliceous, aphanitic dacite, porphyritic dacite with plagioclasephenocrysts, and flow banded dacite. Dacite with hyaloclastic textures are common. W elded and non-welded tuffs associated with the lavas include: greenish-gray to grayish-green, fine tuff, coarse plagioclase crystal tuff and lapilli tuff. Locally, interlayers of immature conglomerate and conglomeratic sandstone with abundant dacite clasts arepresent. T he dacites are interpreted to have been coherent extrusives or very shallow intrusions associated with dome formation. T he tuffs are interpreted as episodicpyroclastic flow deposits, air fall tuffs or rework ed tuffs generated during formation of dacite domes. T he unit occurs as map scale pods surrounded by clastic rock s of Z he/plunit. W ortman et al. (2000) reports an age of 615.7+3.7/-1.9 Ma U-Pb zircon date for a dacitic tuff from the unit in the Rougemont quadrangle.Zh adlt (u) – Andesitic to dacitic lavas and tu ffs of th e u ppe r portion of th e Hyco Form ation: Black to dark gray, gray-green to green; aphanitic andesite to dacite andporphyritic andesite to dacite with plagioclase phenocrysts. Hyaloclastic textures are common. Interlayed with the lavas are gray to black ; welded and non-welded; coarsetuff, lapilli tuff, and tuff breccia. Rock s interpreted as andesites have distinct interior weathering rind of light brown to gray and fresh surfaces exhibit non-vitric lik e texturesin contrast to dacites.Zh a b lt – Andesitic to b asa ltic lavas and tu ffs: Green, gray-green, gray, dark gray and black ; typically unfoliated, amygdaloidal, plagioclase porphyritic, amphibole/pyroxeneporphyritic and aphanitic; andesitic to basaltic lavas and shallow intrusions. Hyaloclastic texture is common and imparts a fragmental texture similar to a lithic tuff on someoutcrops. Locally interlayered with meta-sediments identical to the Z he/pl unit.

REFERENCES:Bowman, J.D., 2010,. T he Aaron Formation: Evidence for a New Lithotectonic Unit in Carolina, North Central North Carolina, unpublished masters thesis, North Carolina S tate University, Raleigh, North Carolina, 116 p.Bradley, P.J., Gay, N.K ., Bechtel, R. and Clark , T.W ., 2007, Geologic map of the Farrington 7.5-minute quadrangle, Chatham, Orange and Durham Counties, North Carolina: North Carolina Geological S urvey Open-file Report 2007-03, scale 1:24,000, in color.Bradley, P.J. and Miller, B.V., 2011, New geologic mapping and age constraints in the Hyco Arc of the Carolina terrane in Orange County, North Carolina: Geological S ociety of America Abstracts with Programs, Vol. 43, No. 2.Clark , T.W ., Blak e, D.E., S toddard, E.F., Carpenter, P.A., III, and Carpenter, R.H., 2004, Preliminary bedrock geologic map of the Raleigh 30’ x 60’ quadrangle, North Carolina: North Carolina Geological S urvey Open-file Report 2004-02, scale 1:100,000, in color.Eligman, D., 1987, Volcanic stratigraphy in the Carolina slate belt near Chapel Hill, North Carolina, unpublished masters thesis, University of North Carolina at Chapel Hill, 51 p.Fisher, R.V. and S chminck e H.-U., 1984, Pyroclastic rock s, Berlin, W est Germany, S pringer-Verlag, 472 p.Glover, L., and S inha, A., 1973, T he Virgilina deformation, a late Precambrian to Early Cambrian (?) orogenic event in the central Piedmont of Virginia and North Carolina, American Journal of S cience, Cooper v. 273-A, pp. 234-251.Harris, C., and Glover, L., 1985, T he Virgilina deformation: implications of stratigraphic correlation in the Carolina slate belt, Carolina Geological S ociety field trip guidebook, 36 p.Harris, C., and Glover, 1988, T he regional extent of the ca. 600 Ma Virgilina deformation: implications of stratigraphic correlation in the Carolina terrane, Geological S ociety of America Bulletin, v. 100, pp. 200-217.Hibbard, J., S amson, S., 1995, Orogenesis exotic to the Iapetan cycle in the southern Appalachians, In, Hibbard, J., van S taal, C., Cawood, P. editors, Current Perspectives in the Appalachian– Caledonian Orogen. Geological Association of Canada S pecial Paper, v. 41, pp. 191–205.Hibbard, J., S toddard, E.F., S ecor, D., Jr., and Dennis, A., 2002, T he Carolina Z one: Overview of Neoproterozoic to early Paleozoic peri-Gondw anan terranes along the eastern flank of the southern Appalachians: Earth S cience Reviews, v. 57, n. 3/4, p. 299-339.Hibbard, J. P., van S taal, C. R., Rank in, D. W ., and W illiams, H., 2006, Lithotectonic map of the Appalachian Orogen, Canada-United S tates of America, Geological S urvey of Canada, Map-2096A. 1:1,500,000-scale.Hoffman, C. W ., and Gallagher, P. E., 1989, Geology of the S outheast Durham and Southw est Durham 7.5-minute quadrangles, North Carolina Geological S urvey Bulletin 92, 34 p.Le Maitre, R.W ., Ed., 2002, Igneous Rock s: A Classification and Glossary of T erms: Recommendations of the International Union of Geological S ciences (IUGS) S ubcommission on the S ystematics of Igneous Rock s: Cambridge, Cambridge University Press, 252 p.Pollock , J. C., 2007, T he Neoproterozoic-Early Paleozoic tectonic evolution of the peri-Gondw anan margin of the Appalachian orogen: an integrated geochronological, geochemical and isotopic study from North Carolina and New foundland. Unpublished PhD dissertation, North Carolina S tate University, 194 p.Reinemund, J.A., 1955, Geology of the Deep River coal field, North Carolina: U.S. Geol. S urvey Prof. Paper 246, 159 p.S amson, S.D. and S ecor, D., 2001, W andering Carolina: T rack ing exotic terranes with detrital Z ircons, GSA Abstracts with Programs Vol. 33, No. 6, p. A-263T adlock , K .A. and Loewy, S.L., 2006, Isotopic characterization of the Farrington pluton: constraining the Virgilina orogeny, in Bradley, P.J., and Clark, T.W ., editors, T he Geology of the Chapel Hill, Hillsborough and Efland 7.5-minute Quadrangles, Orange and Durham Counties, Carolina T errane, North Carolina, Carolina Geological S ociety Field T rip Guidebook for the 2006 annual meeting, pp. 17-21.W agener, H.D., 1964, Areal modal variation in the Farrington igneous complex, Chatham and Orange counties, North Carolina, unpublished M.S. thesis, University of North Carolina at Chapel Hill, 51 p.W agener, H.D., 1965, Areal modal variation in the Farrington igneous complex, Chatham and Orange Counties, North Carolina, Southeastern Geology, v. 6, no. 2, p. 49-77.W atson, M. E., 1998, Geology of the Green Level 7.5-minute quadrangle, Chatham, Durham, and W ak e Counties, North Carolina, North Carolina Geological S urvey Open-File Report 98-3, 28 p.W ortman, G.L., S amson, S.D., and Hibbard, J.P., 2000, Precise U-Pb zircon constraints on the earliest magmatic history of the Carolina terrane, Journal of Geology, v. 108, pp. 321-338.

NORTH CAROLINA

MAP LOCATION

Trp

Jd

K/Tu

Trcs/si2

Qal

Trcc

Trpc

Zhe/pl

Zhdlt (u)

Zhadlt (u)

Zhablt

INDEX T O GEOLOGIC MAPPING

Bradley and Hanna

Malaska

Not mapped

station location

strik e and dip of inclined joint surface

strik e and dip of inclinedprimary bedding and layering

strik e and dip of inclinedprimary bedding and layering(multiple observations at one locality)

strik e and dip of cleavage

strik e and dip of cleavage(multiple observations at one locality)

strik e and dip of inclined joint surface(multiple observations at one locality)

bearing and plungeof slick enline

contact - location inferred

CONTACTS, FOLDS AND OTHER FEATUR ES

Lithologic contacts - Distribution and concentration of structural symbols indicates degree of reliability.

cross section line

gradational contact

15

22

34

5070

75

6577

75

70

diabase contact -dashed w here inferred,dotted where concealed

Qal contactcontact - location concealed

strik e of vertical joint surface

strik e of vertical joint surface(multiple observations at one locality)

diabase station location

Fault plane - normal74

strik e and dip of quartz vein80strik e of vertical regional foliation

strik e and dip ofinclined regional foliation(multiple observations at one locality)

50

74

strik e and dip of primary flow banding75

strik e of vertical regional foliation(multiple observations at one locality)

strik e and dip ofinclined regional foliation

60

strik e and dip of primary volcaniccompaction and/or welding foliation

74

S trik e and dip of cataclastic cleavageinterpreted as a result of brittle deformation

S trik e and dip of cataclastic cleavageinterpreted as a result of brittle deformation(multiple observations at one locality)

6560

76

brittle fault - inferredBonsal - Morrisville Fault(approximate location)

fold axis - overturned anticline - inferredcontact - location knownfold axis - overturned syncline - inferred

A A'

Geology mapped between August 2011 and July 2012.

in cross section, fold form lines

Zhe/pl

Jd

Trp

Qal

Trcc

Trpc

K/Tu

Zhablt

Zhadlt (u)

Trcs/si2

Zhdlt (u)

Hyco Formation

diabase

Triassic Sedimentary Rocks

alluvium (Qal)

conglomerate (Trcc) of theChatham Group and sandstonewith interlayered siltstone of the Chatham Group LithofaciesAssociation II (Trcs/si2)

post-Chatham Group undifferentiated sediments (K/Tu)

Deep River Basin: Durham and Sanford Sub-basins

Metamorphic Rocks

metamorphosed volcaniclastic sedimentaryand pyroclastic rocks associated with HycoFormation: upper portion (stratigraphic relationsuncertain) ca. 613 - 616 Ma (Wortman et al.,2000; Bowman, 2010; and Bradley and Miller, 2011)

mixed epiclastic-pyroclastic rockswith interlayered dacitic lavas (Zhe/pl)dacitic lavas and tuffs (Zhdlt (u))andesitic to dacitic lavas and tuffs (Zhadlt (u))andesitic to basaltic lavas and tuffs (Zhablt)

QUAT

ERNA

RYME

SOZO

IC(?)

NEOP

ROTE

ROZO

IC

MAP UNITS

conglomerate (Trpc) andinterlayered sandstones, siltstones and mudstonesof the Pekin Formation(Reinemund, 1955)

CONTOUR INTERVAL - 10 FEET

cross section scale - 1:24 000 no vertical exaggeration

35 45' 00"79 07' 30"

in cross section, inferred axialtrace of large-scale fold

abandoned quarry

2010 Magnetic North Declinationat Center of Sheet =

8 degrees 34 minutes West

8 34'

MN

USGS gauging station (part of base map features)

T RAVERSE MAP

by carby foot

Trp

Jd

K/Tu

Trcs/si2

Qal

Trcc

Trpc

Zhe/plZhdlt (u)

Zhadlt (u)

Zhablt