ONE ARC, TWO ARCS OLD ARC, NEW ARC - Carolina Geological

276 Pages·2014·20.21 MB·English

CAROLINA GEOLOGICAL SOCIETY
ANNUAL MEETING AND FIELD TRIP
NOVEMBER 8-10, 2013
SALISBURY, NORTH CAROLINA
E J H
DITORS: AMES IBBARD
J P
AND EFF OLLOCK
O
A T A
NE RC, WO RCS
O A N A
LD RC, EW RC
THE CAROLINA TERRANE IN
CENTRAL NORTH CAROLINA
O A , T A , O
NE RC WO RCS LD
A , N A
RC EW RC
THE CAROLINA TERRANE IN

CENTRAL NORTH CAROLINA

EDITORS: James Hibbard and Jeff Pollock

TRIP LEADERS: James Hibbard, Jeff Pollock,
Dennis LaPoint, Patricia Weaver, John DeDecker,
Phil Bradley, Lee Phillips

LOGISTICAL SUPPORT: Phil Bradley, Tyler Clark,
Robert Ganis

Carolina Geological Society
Annual Meeting, November 8-10, 2013
Salisbury, North Carolina
Carolina Geological Society
http://carolinageologicalsociety.org/

2013 Board of Directors

President Board Members
Mike Waddell
University of South Carolina Allen Dennis
University of South Carolina, Aiken
Vice President
William Ranson Angela Frizzell
Furman University Arcadis US

Paul Johnstone
Secretary Treasurer
AMEC Environment & Infrastructure,
Timothy W. (Tyler) Clark Inc.
Wake Tech Community College

[email protected]

Past President

Scott Howard

South Carolina Geological

Survey

ON THE COVERS
Front: Graduate students Laura Lukes, Dillon Nance, and John DeDecker between a rock and a
hard place. Outcrops of Stony Mountain Gabbro on Ridges Mountain, Randolph County, North
Carolina (see DeDecker et al., this volume).

Inside back cover: Sponsors of the 2013 Carolina Geological field trip.

Back: Stop map for the 2013 Carolina Geological Society field trip. Base map for stops by Phil
Bradley incorporates regional LiDAR coverage (from NCDOT and NC Flood Plain Mapping)
for central North Carolina with a portion of the Lithotectonic Map of the Appalachian Orogen
(Hibbard et al., 2006).

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TABLE OF CONTENTS

2013 BOARD OF DIRECTORS ………………………………………………………………. ii

FOREWORD ……………………………………………………………………………… iv

AN APPRECIATION TO THOSE WHO WENT BEFORE ……………………………… iv

ACKNOWLEDGMENTS ……….……………………………………………………………. viii

FIELD GUIDE TO STOPS ………………………………………………………. 1

SATURDAY, NOVEMBER 9, 2013

Stop 1.1 Five Pines Sequence crystal lithic tuff ....................................................................... 3

Stop 1.2 Five Pines Sequence phyllite ....................................................................................... 4

Stop 1.3 Structure in Vulcan Gold Hill quarry ........................................................................ 5

Stop 1.4 Gold Hill Mines Historic Park (Lunch) ……………………………………………. 7

Stop 1.5 Flat Swamp Member volcanics .................................................................................. 10

Stop 1.6 Floyd Church Formation, Albemarle ......................................................................... 11

Stop 1.7 Stony Mountain Gabbro at the vineyard ................................................................... 12

SUNDAY, NOVEMBER 19, 2013

Stop 2A.1 Jacob’s Creek quarry main pit …………………………………………………… 14

Stop 2A.2 Jacob’s Creek quarry Cid mudstone – Flat Swamp contact ................................ 17

Stop 2B Reed Gold Mine ............................................................................................................ 18

SUPPLEMENTAL STOPS

Stop S-1 Gold Hill fault on High Rock Lake .......................................................................... 24

Stop S-2 Folds in Five Pines sequence ..................................................................................... 25

Stop S-3 Volcanic rocks in Gold Hill shear zone .................................................................... 27

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Stop S-4 Gold Hill fault hanging wall on Abbot’s Creek ……………………………………. 28

Stop S-5 Erect Member of the Uwharrie Formation ………………………………………… 29

Stop S-6 Aaron Formation near Siler City …………………………………………………... 30

SCIENTIFIC PAPERS

OVERVIEWS

One arc, two arcs, old arc, new arc: an overview of the Carolina terrane in central North
Carolina
James P. Hibbard, Jeffrey C. Pollock, Philip J. Bradley ……………………………………… 35

Overview of Ediacaran age fossils from the Carolina terrane: past, present, and future
research
Patricia G. Weaver and Robert Ganis …………………………………………………………... 63

Geochronologic and thermochronologic database of the southern Appalachian orogeny
Brent V. Miller …………………………………………………………………………………… 75

Gold and base metal mineralization in the Carolina terrane of central North Carolina
Dennis J. LaPoint and Robert J. Moye ………………………………………………………… 91

Carolinia – a distinct block in the Neoproterozoic peri-Gondwanan realm? How oxygen-
isotope terrane mapping provides insights into tectonomagmatic histories and rock-water
interactions
Joanna Potter, James P. Hibbard, Fred J. Longstaffe ………………………………………. 125

OLD ARC – THE HYCO ARC

The Virgilina sequence redefined, north central North Carolina
Jeffrey D. Bowman, James Hibbard, Brent V. Miller ……………………………………….. 127

The Carolina terrane on the west flank of the Deep River Triassic Basin in the northern
Piedmont of North Carolina – a status report
Philip J. Bradley ……………………………………………………………………………….. 139

NEW ARC – THE ALBEMARLE ARC

The Flat Swamp Mountain caldera and related mineral deposits, Carolina slate belt, central
North Carolina
J. Robert Butler ………………………………………………………………………………… 153

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Field relationship between the Uwharrie Formation and the lower Albemarle Group and
geochemistry of the ‘Morrow Mountain rhyodacites’, central North Carolina: implications for
the stratigraphy of the Albemarle arc
Sonja L. Boorman, Matt P. Brennan, Jill A. Oliver, James P. Hibbard, R.V. Fodor ……….. 155

Geology of the Carolina terrane in the vicinity of the Martin-Marietta Asheboro quarry,
North Carolina: implications for the stratigraphy of the Albemarle arc
Jillian M. Kurek, James P. Hibbard, Brent V. Miller ………………………………………… 175

Ediacaran trace fossils from the Albemarle Group of the Carolina terrane, North Carolina
(USA): marks of a mobile lifestyle on a Precambrian sea bottom
Anthony J. Martin, Patricia G. Weaver ……………………………………………………..... 185

The Deep River gold-copper-molybdenum prospect: Potential subvolcanic porphyry
mineralization in the Hyco arc, central North Carolina
Rachel Rapprecht, Kevin Stewart, Dennis LaPoint, Holly Stein ……………………………... 193

Advanced argillic epithermal alteration systems (AES) in the Carolina terrane of central
North Carolina: possible structural controls and association with Neoproterozoic Uwharrie
felsic magmatism
Robert J. Moye ………………………………………………………………………………….. 213

Preliminary U-Pb TIMS zircon ages from the Stony Mountain Gabbro at Ridges Mountain,
North Carolina: timing of the birth of the Rheic Ocean?
John DeDecker, Drew S. Coleman, James P. Hibbard, Jeffrey C. Pollock ………………... 239

GEOPHYSICS

GPR analysis of an Uwharrie River terrace deposit, Uwharrie National Forest, North
Carolina
Andy Bobyarchick ……………………………………………………………………………… 245

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F
OREWORD

The theme of the 2013 Carolina Geological the terrane that may well shed further light on
Society Annual Meeting and Field Trip is 21st the nature, distribution, and evolution of soft-
century advancements in our understanding of bodied organisms of the Ediacaran. In a
the Carolina terrane in central North Carolina. broader forum, study of Carolinia and other
The Carolina terrane forms the ‘heart’ of Neoproterozoic blocks of the circum-Atlantic
Carolinia, one of the largest accreted crustal region is particularly topical as it sheds light
tracts within the Appalachian Orogen. At on a critical time in Earth history marked by
present, the Carolina terrane provides most of multiple glaciation events at equatorial lati-
our knowledge of Carolinia mainly because its tudes, profound extremes in sea level, ocean
low grade metamorphic overprint and its rel- chemistry and climate and changes in the dis-
atively simple structural style render the tribution of land masses on Earth.
terrane conducive to a variety of topical stud-
ies, e.g. stratigraphic, paleontologic, structural, In addition to academic concerns, it is also
geochronologic, geochemical, and paleomag- timely for the society to return to the Carolina
netic. Although rocks of the Carolina terrane terrane in light of the elevated market value of
in North Carolina have been the subject of gold. The Carolina terrane was host to the first
many previous Carolina Geological Society authenticated gold discovery in the United
trips (e.g. Stromquist and Conley, 1959; States and historically has produced sufficient
Conley, 1962; Bain et al., 1964; LeGrand and quantities of gold to warrant construction of a
Bell, 1966; Gibson and Teeter, 1984; Harris mint in Charlotte, NC in the 1800s. The
and Glover, 1988; Bradley and Clark, 2006) it present high market value of gold has led to
is particularly timely to revisit them now, in significant renewed interest in understanding
2013, because controversies arising during the the origin and distribution of gold and other
1990’s and early 2000’s concerning the strati- metallic deposits in the Carolina terrane. In
graphy and tectonic history of the Carolina addition, multiple other rock commodities are
terrane have recently been addressed with actively extracted from the Carolina terrane –
new data sets. Also, during the past decade e.g. ornamental stone, lightweight aggregate,
there have been new faunal discoveries within and clay for bricks.
A
N APPRECIATION TO THOSE WHO WENT BEFORE
The recent studies summarized in this guide- our modern understanding of the Carolina
book are firmly rooted in the ‘classical’, 20th terrane in North Carolina (Laney, 1910, 1917;
century, foundation studies undertaken by Butler and Ragland, 1969; Butler and Secor,
multiple academic, government, and industry 1991; Glover and Sinha, 1973; Harris, 1984;
geologists who came before us. In particular, Harris and Glover, 1985, 1988; Conley, 1962;
the studies of Francis B. Laney, J. Robert Conley and Bain, 1965; Bain, 1964; Milton,
Butler, Lynn Glover III and his cadre of 1984; Secor et al., 1983; Seiders, 1978, 1981;
graduate students from Virginia Tech - Stromquist and Conley, 1959; Stromquist and
especially Charles Harris - James Conley, Henderson, 1985; Stromquist and Sundelius,
Don Secor, Victor Seiders, George Bain, 1969, 1975; Stromquist et al., 1971). Of these
Arvid Stromquist, Harold Sundelius, and geologists, J. Robert, ‘Bob’ Butler (photo-
Daniel Milton are of seminal importance to graph below), in particular, embodied the sci-

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entific method and in his understated, good-
humored, and humble manner, he objectively
let the rocks tell their story. At the time of his
death in 1996, Bob was in the early stages of
assembling a manuscript on the Flat Swamp
Member of the Cid Formation (Stop 1.5), a
key marker unit in the Carolina terrane of
central North Carolina. In honor of his
unfinished studies, we reproduce his last
publication, a Geological Society of America
abstract on the Flat Swamp caldera (Butler,
1995), in the scientific papers section of this
guidebook.

J. Robert ‘Bob’ Butler at Hanging Rock State Park,
NC, 1989.

REFERENCES Gibson, G. and Teeter, S. 1984. A stratigrapher's view
Bain, G.L., 1964, Metavolcanic and metasedimentary of the Carolina slate belt, south central North
rocks in Chatham and Randolph counties, North Carolina. Carolina Geological Society Field Trip
Carolina. Carolina Geological Society Guidebook Guidebook, Ablemarle, North Carolina: 43 p.

for 1964 Annual Meeting, 10 p. Glover, L., Sinha, A., 1973. The Virgilina deformation,
Bradley, P.J. and Clark, T.W., eds., 2006, The geology a late Precambrian to Early Cambrian (?) orogenic
of the Chapel Hill, Hillsborough, and Efland 7.5’ event in the central Piedmont of Virginia and North
quadrangles, Orange and Durham counties, Carolina. American Journal Science 273-A, 234-251.
Carolina terrane, North Carolina. Carolina Harris, C.W., 1984, Coarse-grained submarine-fan
Geological Society Annual Field Trip Guidebook, deposits of magmatic arc affinity in the late
95 p. Precambrian Aaron Formation, North Carolina,
Butler, J.R., 1995, The Flat Swamp Mountain caldera U.S.A.: Precambrian Research, v. 26, p. 285-306.
and related mineral deposits, Carolina slate belt, Harris, C., Glover, L., 1985. The Virgilina deformation:
central North Carolina. Geological Society of Amer- implications of stratrigraphic correlation in the
ica Programs with Abstracts, v. 27, no. 2., p. 39. Carolina slate belt. Carolina Geological Society
Butler, J. R., Ragland, P., 1969. Petrology and Field Guidebook, 58 p.
chemistry of meta-igneous rocks in the Albemarle Harris, C. and Glover, L., 1988. The regional extent of
area, North Carolina slate belt. American Journal of the ca. 600 Ma Virgilina deformation: Implications
Science 267, 700-726. for stratigraphic correlation in the Carolina terrane.
Butler, J. R., and Secor, D. T., Jr., 1991, The central Geological Society of America Bulletin 100, 200-217.
Piedmont: in Horton, J. W., and Zullo, V. A., eds., LeGrand, H.E. and Bell, H., III, 1966, Guidebook of
The Geology of the Carolinas: Knoxville, Tennessee, excursion in Cabarrus County, North Carolina.
University of Tennessee Press, p. 59-78. Carolina Geological Society Guidebook for 1966
Conley, J., 1962, Geology of the Albemarle quadrangle, Annual Meeting, 16 p.
North Carolina: North Carolina Division of Mineral Milton, D., 1984. Revision of the Albemarle Group,
Resources Bulletin 75, 26 p. North Carolina. U.S. Geological Survey Bulletin
Conley, J., and Bain, G., 1965, Geology of the Carolina 1537-A, pp. A69-A72.
slate belt west of the Deep River-Wadesboro Secor, D.T., Samson, S., Snoke, A.,Palmer, A., 1983.
Triassic Basin, North Carolina: Southeastern Confirmation of the Carolina slate belt as an exotic
Geology 6, 117-138. terrane. Science 221, 649-651.
Seiders, V.M., 1981, Geologic map of the Asheboro,
North Carolina and adjacent areas. U.S. Geological

  vii
Survey Miscellaneous Investigations Map I-1314, 1: U.S. Geological Survey Miscellaneous Investiga-
62,500 scale. tions Series Map I-400.
Seiders, V.M., 1978, A chemically bimodal, calc-alkalic Stromquist, A., and Sundelius, H., 1975, Interpretive
suite of volcanic rocks, Carolina volcanic slate belt, geologic map of the bedrock, showing radioactivity,
central North Carolina. Southeastern Geology, v. 19, and aeromagnetic map of the Salisbury, Southmont,
p. 241-265.Stromquist, A.A. and Conley, J.F., 1959, Rockwell, and Gold Hill quadrangles, Rowan and
Geology of the Albemarle and Denton quadrangles, Davidson counties, North Carolina. U. S.
North Carolina. Carolina Geological Society Field Geological Survey Map I-888, scale 1:48,000.
Trip Guidebook, 36 p. Stromquist, A. and Sundelius, H., 1969, Stratigraphy of
Stromquist, A.A. and Conley, J.F., 1959, Geology of the Albemarle Group of the Carolina slate belt in
the Albemarle and Denton quadrangles, North central North Carolina. U.S. Geological Survey
Carolina. Carolina Geological Society Field Trip Bulletin 1274-B, 22 p.
Guidebook, 36 p. Stromquist, A., Choquette, P., and Sundelius, H., 1971,
Stromquist, A. and Henderson, J., 1985, Geologic and Geologic map of the Denton quadrangle, central
geophysical maps of south-central North Carolina: North Carolina. 1:62,500. USGS Map GQ-872.

A • Ms. Vivian Hopkins of the Historic Gold
CKNOWLEDGMENTS
Hill and Mines Foundation, Inc., for helping
us secure our lunch site at the Gold Hill
Mines Historic Park, Gold Hill, NC.
We thank the following companies for gene-
• Ms. Karen Baldwin of Alcoa Power Gene-
rous sponsorship of this Carolina Geological
rating, Inc for providing an activity permit
Society meeting, which has again, allowed for
for access to the High Rock powerhouse
significantly reduced rates for students:
road.

• Russells Automotive, Albemarle, NC for ac-
Haile Gold Mine Inc. a division of Romarco
cess to their borrow pit.
Minerals Inc.
• The Furr family of Stony Mountain Vine-
RockWare
yards for continued access to their property
Standard Minerals Division of R.T.
on Stony Mountain and for accommodating
Vanderbilt Holding Inc.
many geologists at the end of a long day with
Vulcan Materials
a wine-tasting.

• Mr. Jeff McKinney, Jacob’s Creek quarry,
We are grateful to many people who have
Denton, NC, for free access to the quarry
facilitated our access to view outcrops on
grounds for many years.
private property, including the following:
• Mr. Larry Neal and Ms. Susan Smith of
• Mr. Neal Choquette of American Land
the Reed Gold Mine Historic Site, for ac-
Corp., Inc., for access to the Saratoga hous-
commodating our large group on a Sunday.
ing development, Mt. Pleasant, NC.
• Mike and Sharon Michaels for access to the
• Mr. David Miller of Hammill Construction,
Yow Mill outcrop.
for access to the Immanuel Church quarries,

Gold Hill, NC.
We also appreciate the contributions of stu-
• Mr. Guy Medlin of Vulcan Materials, Inc.
dent helpers Stephen Hughes (NCSU), Tray
for continued access to the Vulcan Materials
McLellan (UNC Pembroke) and Sean Pavia
Gold Hill quarry, Gold Hill, NC, through
(NCSU).
many years of visits and for facilitating our
lunch stop.

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2013 FIELD GUIDE TO STOPS

J. HIBBARD1, J. POLLOCK2, D. LAPOINT3, P. WEAVER4, J.DEDECKER 5, P.
BRADLEY 6, AND L. PHILLIPS 7

1MEAS, Box 8208, North Carolina State University, Raleigh, NC, 27695 2Dept. of Earth Sciences, Mt. Royal
University, Calgary, Alberta, T3E 6K6, Canada 3 Appalachian Resources LLC, P.O. Box 3810, Chapel Hill, NC
27515 4Geology/Paleontology, NC Museum of Natural Sciences, 11 West Jones Street, Raleigh, NC 27601-1029,
[email protected], 919-707-9943 5Department of Geological Sciences, University of North Carolina,
Chapel Hill, NC 27599 6North Carolina Geological Survey, Raleigh, NC 27699-1620 7Director, Office of
Undergraduate Research, UNC Greensboro, Greensboro, NC 27402

This one and a half day field trip will high- tory of the region as well as a recent GPR pi-
lot study carried out above the historic mine
light field mapping and specialized studies that
workings. The first two stops of the afternoon
have been undertaken in the Carolina terrane
will feature units that are of stratigraphic im-
of central North Carolina mainly during the
portance in the Albemarle arc. Our last stop of
first decade of the 21st century. This guide in-
the day will be in the Stony Mountain gabbro,
corporates material from earlier field guides
an important unit for interpreting the tectonics
(e.g. Hibbard et al., 2008) and from the field
of Carolinia and will be followed by a wine
reviews of former NCSU graduate students,
tasting.
including Sonja Boorman, Matt Brennan, Jill

Oliver, Jeff Pollock and Issac Standard. Al-
On day two, attendees will choose between
though one or two of the stops are well-worn
one of two all-morning stops (Back Cover).
classics, essential for any field trip, most of the
Stop 2A will highlight stratigraphic-sediment-
localities are of more recent discovery and
ary features and Ediacaran fauna of the Cid
concern.
mudstone member at the Jacob’s Creek

quarry; Stop 2B will be a tour of the Reed
For those who have experienced field trips in
Gold Mine, a North Carolina Historic Site,
the southern Appalachian Piedmont, you will
and site of the first authenticated discovery of
realize that not all stops will be at photogenic
gold in the United States. For a general
textbook outcrops; the uninitiated will find
background on the geology of the field trip
that outside of quarry stops, our locales will be
area, the reader is referred to the overview
at relatively small, unassuming outcrops, that
paper (Hibbard et al., this volume).
might be difficult for all members of a group

such as ours to view at one time. However,
As with most field guides, there are more stops
the observations and deductions gleaned from
described below than we can comfortably visit
these humble outcrops can have global
in the time allotted. The supplemental stops
ramifications.
are included to both lend flexibility to the

choice of stops in case of unforeseen circum-
The first day stops will represent a traverse
stances (weather, time, etc.) and document im-
across the the Gold Hill shear zone, a first
portant stops that we will not be able to visit
order structure in the western portion of the
on this particular trip. A substantial fraction of
Carolina terrane (back cover; Fig. 1); these
our field work along the Gold Hill fault took
stops will focus on the timing and significance
place during the drought of 2002, when lake
of the shear zone. Lunch will be held at Gold
levels in High Rock Lake dropped to as low as
Hill Mines Historic Park, within the shear
24' below full pool level. Thus, many key
zone. Here we will learn about the mining his-
1