Booker T. Washington National Monument 

Geologic Resources Inventory Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2010/234 

National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 
THIS PAGE: 

A spring box, used as an early refrigerator. Holes at each end of the box 

allow fresh, cool water to flow 

through, keeping perishables cool and 

fresh for several days at a time. 

ON THE COVER: 

The kitchen cabin (right) and smokehouse, historic buildings on the 

Burroughs Plantation where Booker T. 

Washington lived as a boy. 

National Park Service photographs 

courtesy Timbo Sims (Booker T. Washington National Monument) 
Booker T. Washington National Monument 

Geologic Resources Inventory Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2010/234 

Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, Colorado 80225 

August 2010 

U.S. Department of the Interior 

National Park Service 

Natural Resource Program Center 

Fort Collins, Colorado
The National Park Service, Natural Resource Program Center publishes a range of reports that 

address natural resource topics of interest and applicability to a broad audience in the National 

Park Service and others in natural resource management, including scientists, conservation and 

environmental constituencies, and the public. 

The Natural Resource Report Series is used to disseminate high-priority, current natural 

resource management information with managerial application. The series targets a general, 

diverse audience, and may contain NPS policy considerations or address sensitive issues of 

management applicability. 

All manuscripts in the series receive the appropriate level of peer review to ensure that the 

information is scientifically credible, technically accurate, appropriately written for the 

intended audience, and designed and published in a professional manner. This report received 

informal peer review by subject-matter experts who were not directly involved in the 

collection, analysis, or reporting of the data. 

Views, statements, findings, conclusions, recommendations, and data in this report do not 

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Interior. Mention of trade names or commercial products does not constitute endorsement or 

recommendation for use by the U. S. Government. 

Printed copies of this report are produced in a limited quantity and they are only available as 

long as the supply lasts. This report is available from the Geologic Resources Inventory website 

(http://www.nature.nps.gov/geology/inventory/gre_publications.cfm) and the Natural 

Resource Publications Management website (http://www.nature.nps.gov/publications/

NRPM). 

Please cite this publication as: 

Thornberry-Ehrlich, T. 2010. Booker T. Washington National Monument: geologic resources 

inventory report. Natural Resource Report NPS/NRPC/GRD/NRR—2010/234. National Park 

Service, Fort Collins, Colorado. 

NPS 807/105489, August 2010 

ii NPS Geologic Resources Division 
BOWA Geologic Resources Inventory Report iii

Contents

List of Figures................................................................................................................ iv

Executive Summary ....................................................................................................... v

Acknowledgements...................................................................................................... vi

Credits........................................................................................................................................................................ vi

Introduction ................................................................................................................... 1

Purpose of the Geologic Resources Inventory ...............................................................................................................1

Park Setting and Establishment ....................................................................................................................................1

Geologic Setting ..........................................................................................................................................................1

Physiographic and Tectonic Provinces near Booker T. Washington National Monument.................................................2

Geologic Issues .............................................................................................................. 5

Introduction.................................................................................................................................................................5

Water Issues ................................................................................................................................................................5

Erosion ........................................................................................................................................................................6

Adjacent Development.................................................................................................................................................7

Seismicity.....................................................................................................................................................................7

Seeps and Springs........................................................................................................................................................7

Shrink-and-Swell Clays.................................................................................................................................................7

Geologic Features and Processes................................................................................ 12

Geologic Influences on History ...................................................................................................................................12

Weathered Regolith...................................................................................................................................................13

Map Unit Properties .................................................................................................... 15

Geologic History .......................................................................................................... 19

Precambrian and Early Paleozoic Era: Ancient Mountain Building and Iapetus Ocean Formation ..................................19

Paleozoic Era: Appalachian Mountain Building ...........................................................................................................20

Mesozoic Era: Rifting, Atlantic Ocean Formation, and Mountain Erosion.....................................................................21

Cenozoic Era: Shaping the Modern Landscape............................................................................................................22

Glossary........................................................................................................................ 28

Literature Cited............................................................................................................ 33

Additional References ................................................................................................. 36

Geology of National Park Service Areas......................................................................................................................36

Resource Management/Legislation Documents...........................................................................................................36

Geological Survey Websites........................................................................................................................................36

Other Geology/Resource Management Tools..............................................................................................................36

Appendix A: Overview of Digital Geologic Data....................................................... 37

Attachment 1: Geologic Resources Inventory Products CD
iv NPS Geologic Resources Division 

List of Figures

Figure 1. Map of Booker T. Washington National Monument in Hardy, Virginia................................................................3

Figure 2: Location of the monument relative to the tectonic provinces and major faults of west-central Virginia ...............4

Figure 3: Location of the monument relative to the physiographic provinces and subprovinces of Virginia ........................4

Figure 4: Rocks within Gills Creek, which is part of the monument’s west boundary and flows through the monument....8

Figure 5: Jack-O-Lantern Branch originates within the monument and forms the east and south boundary.......................8

Figure 6: The bedrock channel of Jack-O-Lantern Branch at Booker T. Washington National Monument...........................9

Figure 7: Gravel and finer sediments within a meander along Jack-O-Lantern Branch .......................................................9

Figure 8: Jack-O-Lantern Branch flowing west with increased flow and volume ..............................................................10

Figure 9: Weathered outcrop on eroded, reforested landscape within the monument ....................................................10

Figure 10: Undercut slope along a small, unnamed tributary ..........................................................................................11

Figure 11: Jack-O-Lantern Branch within 100 m (300 ft) of its confluence with Gills Creek..............................................11

Figure 12: Bedrock ledges along Jack-O-Lantern Branch.................................................................................................13

Figure 13: “Whale Rock” along the western-flowing Jack-O-Lantern Branch...................................................................14

Figure 14: Rock piles on west-facing slopes in the forested area southwest of the monument headquarters. ..................14

Figure 15: Geologic time scale .......................................................................................................................................23

Figure 16: Geologic time scale specific to Virginia ..........................................................................................................24

Figure 17: Geologic evolution of the Appalachian Mountains.........................................................................................25

Figure 18: Geologic evolution of the Appalachian Mountains, continued........................................................................26

Figure 19: Geologic evolution of the Appalachian Mountains, continued........................................................................27
BOWA Geologic Resources Inventory v

Executive Summary

This report accompanies the digital geologic map data for Booker T. Washington National 

Monument in Virginia, produced by the Geologic Resources Division in collaboration with 

its partners. It contains information relevant to resource management and scientific 

research. This document incorporates preexisting geologic information and does not include 

new data or additional fieldwork.

Established in 1956, Booker T. Washington National 

Monument covers 97 ha (239 ac) in Franklin County, 

Virginia, and preserves the tobacco plantation setting of 

the birthplace of Booker T. Washington. The purpose of 

the monument is to commemorate the achievements and 

legacy of Washington, who rose from slavery and 

poverty to be one of the most influential African 

Americans of the late 19th and early 20th centuries. The 

monument preserves many cultural resources, including 

replica slave cabins and plantation outbuildings, a 20th 

century segregated schoolhouse, and several cemeteries 

in an agrarian setting typical of the time in which 

Washington was born.

The monument lies near the western Piedmont-Blue 

Ridge transitional zone, which is underlain by hard 

crystalline metamorphic rocks such as schist, gneiss, and 

amphibolite. This area of Virginia contains numerous 

belts of rocks that accreted onto the North American 

continent during repeated continental collisions and 

mountain building (orogenic) events, culminating in the 

formation of the Appalachian Mountain chain. Large 

thrust sheets slid atop one another along major faults 

such as the Fries Fault, located just to the west of the 

monument. The regional geologic history spans more 

than 700 million years through the present regime of 

weathering, erosion, and anthropogenic land use 

patterns. 

Geology forms the foundation of the ecosystem at 

Booker T. Washington National Monument and has 

influenced historical events, as well as surface water 

quality, water supply, sediment load, channel 

morphology, erosion, seismicity, adjacent development 

practices, seeps and springs, and shrink-and-swell clays. 

Geologic knowledge is essential in understanding 

landscape evolution and anthropogenic impacts, and for 

the siting of future facilities. 

Resource managers should understand how water is 

moving through and under the monument; thus, 

hydrogeologic modeling is critical in determining the 

impacts of human-induced contaminants on the entire 

ecosystem as well as in predicting groundwater table 

changes. Several springs and seeps exist within 

monument boundaries and the nature of their formation 

is unknown.

Geologic processes such as erosion can impact the 

cultural landscape and natural systems in the park. 

Erosion can distort the landscape and increase sediment 

loads and meandering in local waterways, damaging the 

aquatic and riparian environments. Severe erosion in the 

past has created gulleys within the now forested slopes of 

the monument. 

Adjacent land development has strongly impacted both 

the viewshed and hydrologic system at the monument. 

The mixed forest and agrarian landscape is rapidly being 

tranformed to housing developments and commercial 

centers, impacting the historic context of the area. 

Development practices have increased surface runoff 

following rain storms and increased erosion and 

sediment loading in Gills Creek and Jack-O-Lantern

Branch. 

Rocks in the Booker T. Washington National Monument 

area typically occur in elongated parallel belts trending 

northeast-southwest reflecting the orogenic processes 

that occurred during the accretion of terranes and the 

mountain building events of the Paleozoic Era. These 

large belts or thrust sheets of rocks are separated by 

major faults. The rocks of this area reflect a complex 

deformational and metamorphic history. The park sits 

atop Late Proterozoic- to early Cambrian-age bedrock 

that includes biotite gneiss and schist, 

metaconglomerate, amphibolite, mica schist, quartzite, 

marble, and actinolite schist. Cutting through these rocks 

are small-scale faults, fractures, mylonite zones, foliation, 

and minor folds; small-scale joints and fractures are 

ubiquitous. Most joints and fractures follow the 

northeast-southwest regional structural trend. Parallel 

thrust faults cut through the monument area, and may 

still be accommodating crustal stresses.

From the first settlers and farmers through modern 

development, geology has played a fundamental role in 

the evolution of Booker T. Washington National 

Monument. Geologic features and processes affect 

topographic expression, streams and rivers, soils, 

wetlands, vegetation patterns, and the animal life that 

thrives in the environment. Geographically, this 

transitional area is part of the tobacco belt. The “sweet” 

soil supported a cash crop for the Burroughs’ plantation 

where Washington was born in 1856. The geological 

landscape in south-central Virginia underscores the 

relationship between geology and history. Both the 

geologic resources and the natural history of the area 

should be emphasized and interpreted to enhance the 

visitor’s experience of Booker T. Washington National 

Monument.
vi NPS Geologic Resources Division 

Acknowledgements

The Geologic Resources Inventory (GRI) is one of 12 inventories funded by the National 

Park Service Inventory and Monitoring Program. The GRI is administered by the 

Geologic Resources Division of the Natural Resource Program Center.

The Geologic Resources Division relies heavily on 

partnerships with institutions such as the U.S. Geological 

Survey, Colorado State University, state geologic surveys, 

local museums, and universities in developing GRI 

products.

Special thanks to: Timbo Sims (Booker T. Washington 

National Monument) for his enthusiasm for this project 

and for providing information and photographs for use 

in the report. William S. Henika (Booker T. Washington 

National Monument volunteer) provided additional 

information and photographs.

William Henika wishes to credit the Virginia Division of 

Geology and Mineral Resources, and the U.S. Geological 

Survey StateMap Program.

Credits

Author

Trista L. Thornberry-Ehrlich (Colorado State 

University)

Review

Mark Carter (U.S. Geological Survey)

Jason Kenworthy (NPS Geologic Resources Division)

Editing

Jeffrey Matthews (Write Science Right)

Digital Geologic Data Production

Andrea Croskrey (NPS Geologic Resources Division)

Stephanie O’Meara (Colorado State University)

Digital Geologic Data Overview Layout Design

Phil Reiker (NPS Geologic Resources Division)
BOWA Geologic Resources Inventory Report 1

Introduction

The following section briefly describes the National Park Service Geologic Resources 

Inventory and the regional geologic setting of Booker T. Washington National 

Monument.

Purpose of the Geologic Resources Inventory 

The Geologic Resources Inventory (GRI) is one of 12 

inventories funded by the National Park Service (NPS) 

Inventory and Monitoring Program. The GRI, 

administered by the Geologic Resources Division of the 

Natural Resource Program Center, is designed to 

provide and enhance baseline information available to 

park managers. The GRI team relies heavily on 

partnerships with institutions such as the U.S. Geological 

Survey, Colorado State University, state geologic surveys, 

local museums, and universities in developing GRI 

products.

The goals of the GRI are to increase understanding of the 

geologic processes at work in parks and to provide sound 

geologic information for use in park decision making. 

Sound park stewardship requires an understanding of 

the natural resources and their role in the ecosystem. 

Park ecosystems are fundamentally shaped by geology.

The compilation and use of natural resource information 

by park managers is called for in section 204 of the 

National Parks Omnibus Management Act of 1998 and in 

NPS-75, Natural Resources Inventory and Monitoring 

Guideline. 

To realize these goals, the GRI team is systematically 

conducting a scoping meeting for each of the 270 

identified natural area parks and providing a parkspecific digital geologic map and geologic report. These 

products support the stewardship of park resources and 

are designed for non-geoscientists. Scoping meetings 

bring together park staff and geologic experts to review 

available geologic maps and discuss specific geologic 

issues, features, and processes. 

The GRI mapping team converts the geologic maps 

identified for park use at the scoping meeting into digital 

geologic data in accordance with their Geographic 

Information Systems (GIS) Data Model. These digital 

data sets bring an interactive dimension to traditional 

paper maps. The digital data sets provide geologic data 

for use in park GIS and facilitate the incorporation of 

geologic considerations into a wide range of resource 

management applications. The newest maps contain 

interactive help files. This geologic report assists park 

managers in the use of the map and provides an overview 

of park geology and geologic resource management 

issues.

For additional information regarding the content of this 

report and current GRI contact information please refer 

to the Geologic Resources Inventory web site 

(http://www.nature.nps.gov/geology/inventory/).

Park Setting and Establishment

Booker T. Washington National Monument, located in

Franklin County, western Virginia, is just east of the Blue 

Ridge Parkway and covers 97 ha (239 ac) (fig. 1). It is 35 

km (22 mi) south of the major town of Roanoke, Virginia. 

The monument was authorized on April 2, 1956 to 

commemorate the birthplace of one of the most 

successful and influential African Americans of the late 

1800s and early 1900s. The monument recreates an 1850s

middle class farm, containing a tobacco barn, 

reconstructed plantation outbuildings (slave cabin, 

smoke house, blacksmith shop, privy, hog pen, duck lot, 

and chicken house), three small cemeteries, marked 

archaeological sites, and two walking trails. According to 

the monument’s 2012 strategic plan, the purpose of the 

monument is, in part, to preserve and protect the 

birthplace, its cultural and natural landscape, and 

agrarian viewshed. 

Booker T. Washington was born to a slave cook on April 

5, 1856 on the Burroughs tobacco plantation. After 

gaining his freedom in 1865 at the end of the American 

Civil War, Washington went on to get an education at the 

Hampton Institute, and helped found the Tuskegee 

Normal and Industrial School in Alabama in 1881

(Tuskegee Institute National Historic Site). A noted 

educator, Washington held the position of first principal 

at Tuskegee Institute at age 26. He believed education 

was the true path to freedom and independence for 

himself and others. Later, as an adviser, author, and 

orator, his experiences with slavery strongly influenced

his philosophies. He thought that the path to civil rights 

for African Americans would follow economic viability 

through skilled trades and education. Washington was 

very influential and powerful during a period of growing 

racial hostility and violence as the southern states 

struggled to recover from the Civil War.

Additional park information may be found at 

http://www.nps.gov/bowa, the Booker T. Washington 

National Monument web site. The glossary contains 

definitions of many geologic terms used in the report. 

Refer to figure 15 for a geologic time scale.

Geologic Setting

Booker T. Washington National Monument is located on 

the western border of the Piedmont physiographic 

province (Piedmont Upland or Foothills physiographic 

subprovince) near the eastern edge of the Blue Ridge 

physiographic province. The Piedmont surface descends 

gently eastward from the Blue Ridge Mountains to Smith 

Mountain Lake (William S. Henika, geologist, Virginia 

Department of Natural Resources, written 

communication 2009). Gently rolling hills underlain by 

deeply weathered Precambrian metamorphic schist, 
2 NPS Geologic Resources Division 

granite, and gneiss characterize the geology of this area 

of the Eastern Blue Ridge geologic belt (Henika 1992; 

1997; William S. Henika, geologist, Virginia Department 

of Natural Resources, written communication 2009). 

Most of the underlying Precambrian rocks formed in rift 

basins which opened approximately 750 million years 

ago as a result of the breakup of the megacontinent, 

Rodinia, and the opening of the Iapetus basin (Henika 

1997; Dalziel 1995). Rift basin deposits (resting atop 

metamorphic and igneous basement rocks) formed 

during the Grenville Orogeny over one billion years ago. 

Rocks of the Greenville Orogeny are the fundamental 

geologic units of the Blue Ridge Province (Henika et al. 

2000).

The landscape within the monument is gently sloping

with rolling hills and valleys. In general, large terrace and 

alluvial fan deposits cap the interfluve highlands and 

active stream valleys are commonly filled with 

unconsolidated alluvium (William S. Henika, geologist, 

Virginia Department of Natural Resources, written 

communication 2009). Elevations range from the low 

point of less than 260 m (840 ft) near the confluence of 

Gills Creek and Jack-O-Lantern Branch to just over

300 m (1,000 ft) near the monument entrance road

(fig. 1). These two streams are the only perennial 

waterways at the monument and are part of the larger 

Roanoke River watershed. Two unnamed streams, and 

numerous seeps and springs also occur within the 

monument, some of which form the source of Jack-OLantern Branch (GRI scoping notes 2009).

Most of the Precambrian to early Cambrian rocks within 

this area are deeply weathered and overlain by thick rock 

debris and soil called regolith (Woodward 1932; Henika 

1997). Regional streams dissect the highlands turning 

them into valleys and ridges. The Roanoke River is the 

southernmost stream that breaches the Blue Ridge 

Thrust Sheet (fig. 2) separating the single, narrow ridge 

to the northeast from the broader, dissected upland to 

the southwest (Dietrich 1990). The Blue Ridge province 

south of the Roanoke River gradually increases in 

breadth and generally increases in elevation (Dietrich 

1990).

The major structural feature of the area is called the Blue 

Ridge anticlinorium, a regional assemblage of folded and 

deformed rocks. In this part of Virginia, rocks of the Blue 

Ridge anticlinorium are not confined to the Blue Ridge 

physiographic province, but include areas of the western 

Piedmont physiographic province as well (figs. 2 and 3)

(Conley 1985). Complex stacks of folded and thrust-fault 

bounded rocks characterize the geologic framework of 

the area (Woodward 1932). There is a strong northeast to 

southwest trend to these features. Booker T. Washington 

National Monument contains rocks of the Fries thrust 

sheet, separated from the Blue Ridge thrust sheet to the 

west by the Fries Fault, and separated from the Smith 

River allochthon (mass of redeposited and transported 

rocks) to the east by the Ridgeway Fault (fig. 2) 

(Bartholomew 1981; Henika 1997). The Fries Fault, also 

known as the Fries thrust, locally occurs as a wide zone 

of deformed granitic gneiss juxtaposing the Ashe 

Formation in the southeast against the Unicoi Formation 

to the northwest (O’Hara 1990)(see Map Unit Properties 

section and Appendix A). Within the Fries thrust sheet 

are several large faults including the Bowens Creek Fault 

and many overturned or recumbent anticlines and 

synclines (Henika 1997). An anticlinal (“A”-shaped fold)

structure trends northeast-southwest across the 

southern end of the monument. 

Different rock units and their geologic structures’

varying resistances to erosion control the topographic 

expression of the area. Relatively resistant rocks such as 

quartzites create topographic highs (Woodward 1932). 

Southeast of the monument, steep-sided ridges are 

upheld by resistant mica schist and quartzite layers 

(Smith Mountain) (William S. Henika, geologist, Virginia 

Department of Natural Resources, written 

communication 2009). Local mountains include 

Thornton Mountain, Brier Mountain, Jacks Mountain, 

Cooks Knob, and Grassy Hill (Conley 1985). Three 

geologic units are exposed within the monument: 

laminated mica gneiss, the Ashe Formation (biotite 

gneiss and schist), and amphibolite (Henika 1997)(see 

Map Unit Properties section and Appendix A). These 

units are deeply weathered, buried by thick soil and 

regolith, and may only be visible along streambeds (GRI 

scoping notes 2009). 

Physiographic and Tectonic Provinces near Booker T. 

Washington National Monument

Piedmont Province

The eastward-sloping Piedmont is located between the 

Blue Ridge province along the eastern edge of the 

Appalachian Mountains and the Atlantic Coastal Plain 

province to the east (fig. 3). The Fall Line (also known as 

the Fall Zone) marks a transitional zone where the softer, 

less consolidated sedimentary rock of the Atlantic 

Coastal Plain province to the east onlaps the harder, 

more resilient metamorphic rock to the west, forming an 

area of ridges, waterfalls, and rapids. The Piedmont 

physiographic province encompasses the Fall Line 

westward to the Blue Ridge Mountains. The Piedmont 

Plateau is composed of crystalline igneous and 

metamorphic rocks such as schists, phyllites, slates, 

gneisses, and gabbros. This province formed through a 

combination of folds, faults, uplifts, accretions, and 

erosion. The resulting landscape of gently rolling hills,

starting at an elevation of 60 m (200 ft), becomes 

gradually steeper and higher in elevation toward the 

western edge where it reaches an elevation of 300 m 

(1,000 ft) above sea level. In the monument area, the 

Piedmont is subdivided into three subprovinces, from 

west to east: the western Piedmont (also called Foothills 

subprovince), containing numerous distinct belts; the 

Mesozoic lowlands subprovince; and the Outer 

Piedmont subprovince (fig. 3) (Bailey 1999). Several 

Mesozoic-age extensional basins (also called the 

Mesozoic lowlands subprovince) cut through the 

Piedmont locally, including the Danville and Farmville 

basins east of Booker T. Washington National 

Monument. They are on the eastern side of the Smith 

River allochthon (Goodwin et al. 1986).
BOWA Geologic Resources Inventory Report 3

Blue Ridge Province

The Blue Ridge province is located along the eastern 

edge of the Appalachian Mountains. It represents one of 

the most geologically complex regions in the world 

(Seaton and Burbey 2005). The highest elevations in the 

Appalachian Mountain system occur within the Black 

Mountain range, northeast of Asheville, North Carolina 

where Mount Mitchell rises to 2,037 (6,684 ft) above sea 

level (Mark Carter, geologist, U.S. Geological Survey, 

written communication 2009). Proterozoic and Paleozoic

igneous, sedimentary, and metamorphic rocks were 

uplifted during several orogenic events (i.e., Taconic, 

Acadian, and Alleghanian) to form the steep rugged

terrain. Resistant Cambrian quartzite forms most of the 

high ridges, whereas Proterozoic metamorphic rocks 

underlie the valleys (Woodward 1932). The elongated 

belt of the Blue Ridge stretches from Georgia to 

Pennsylvania. Eroding streams have caused narrowing in 

the northern section of the Blue Ridge Mountains into a 

thin band of steep ridges that rise to heights of 

approximately 1,200 m (3,900 ft). These streams link the 

adjacent Valley and Ridge and Piedmont provinces

(fig. 3).

Valley and Ridge Province

Long parallel ridges separated by valleys (100 to 200 m 

[330 to 660 ft] deep) characterize the landscape of the 

Valley and Ridge physiographic province. The landforms 

are strongly representative of the lithology and structure 

of the deformed bedrock: valleys formed in easily eroded 

shale and carbonate formations among resistant 

sandstone ridges (Woodward 1932). The province 

contains strongly folded and faulted sedimentary rocks 

in western Virginia. The eastern portion is part of the 

Great Valley; this section is rolling lowland formed on 

folded carbonate rocks and shale. The city of Roanoke 

sits within this valley about 26 km (16 mi) northwest of

Booker T. Washington National Monument.

Figure 1. Map of Booker T. Washington National Monument in Hardy, Virginia. Note orientation of park map (north is to the left). 

National Park Service graphics.
4 NPS Geologic Resources Division 

Figure 2: Location of Booker T. Washington National Monument relative to the tectonic provinces and major faults of west-central 

Virginia. The “Geologic History” section describes the history and relationships between these different groups of rocks. Graphic is 

adapted from Henika (1997). 

Figure 3: Location of Booker T. Washington National Monument relative to the physiographic provinces and subprovinces of Virginia. 

Graphic is adapted from Bailey (1999). 
BOWA Geologic Resources Inventory Report 5

Geologic Issues

The Geologic Resources Division held a Geologic Resources Inventory scoping session for

Booker T. Washington National Monument on August 27, 2009, to discuss geologic 

resources, address the status of geologic mapping, and assess resource management 

issues and needs. This section synthesizes the scoping results, in particular those issues 

that may require attention from resource managers. Contact the Geologic Resources 

Division for technical assistance.

Introduction

Issues in this section are identified in relative order of 

resource management significance with the most critical 

listed first. Potential research projects and topics of 

scientific interest are presented at the end of each

section.

Water Issues

Several secondary, non-navigable streams traverse the 

landscape at Booker T. Washington National 

Monument. Jack-O-Lantern Branch is a tributary of Gills 

Creek which is the largest stream in the monument

(figs. 4 and 5). The tributaries originate at springs located 

inside and outside of park boundaries. Streams within 

the park mostly have bedrock channels with wide 

patches of sand and gravel accumulated in meanders 

(figs. 6 and 7). Some gravel deposits near the 

southwestern boundary of the monument may be up to

6 m (20 ft) thick (William S. Henika, geologist, Virginia 

Department of Natural Resources, written 

communication 2009). 

High flow events and continued development around the 

park may impact fluvial ecosystems within the 

monument (fig. 8). Park staff have noted increased 

stream flow caused by more localized precipitation from 

severe seasonal storms (possibly influenced by climate 

change) as well as runoff over impervious surfaces from 

adjacent developments such as parking lots, roads, and 

buildings (GRI scoping notes 2009). According to Karl et 

al. (2009), climate change in this part of the country will 

produce increases in severe, seasonal storms. During 

high flow events, erosion causes degradation of the 

aquatic and riparian environments in the monument 

because of increased sediment load (GRI scoping notes 

2009). A group affiliated with the University of Virginia 

and Virginia Polytechnic Institute and State University 

(Virginia Tech) are taking monthly sediment load 

readings and looking at water chemistry as part of a 

natural resource assessment in the monument. John 

Karish (NPS Northeast Region) and Jim Comiskey (NPS 

Mid-Atlantic Inventory and Monitoring Network) are 

contacts for this project.

A major goal of the monument is to maintain the high 

water quality that typically exists in the park streams 

(GRI scoping notes 2009). Chemical and biological 

factors are monitored in the monument. To best manage 

this resource an understanding of the hydrogeologic 

system is crucial. Resource managers should understand 

how water is flowing through the park both above and 

below the ground surface. Hydrogeologic models 

specific to the monument area could provide invaluable 

tools for resource managers (Seaton and Burbey 2005).

These kinds of data are needed to monitor future 

influences of increasing urban development surrounding 

the monument (GRI scoping notes 2009) as well as 

potential impacts from climate change.

Groundwater is generally stored in fractures within the 

crystalline bedrock of the Blue Ridge and Piedmont 

provinces and flows in the direction of the lowest outlet, 

in this case, Gills Creek (Gilliam and Henika 1999). The 

hydrogeologic system and groundwater resources 

underlying the monument are greatly influenced by 

fractures, depth to bedrock, soil and regolith thickness 

and mineralogy (the composition of soils and regolith 

reflects the original chemistry and lithology of the 

bedrock), and northeast-southwest trending geologic 

structures such as faults (William S. Henika, geologist, 

Virginia Department of Natural Resources, written 

communication 2009).

Regional studies indicate that high-permeability zones 

occur in brittle crystalline rocks above regional thrust 

faults occurring at depths of 300 m (1,000 ft) or more 

(Seaton and Burbey 2005). These faults may 

compartmentalize the deep aquifer system. Southeast of 

the monument, Smith Mountain Lake is a large 

hydropower reservoir held against a narrow, northeasttrending mica schist ridge along the Brevard-Bowens 

Creek fault zone which acts as a confining zone (Conley 

1985; Henika 1997; Hibbard et al. 2001; William S. 

Henika, geologist, Virginia Department of Natural 

Resources, written communication 2009). If such faults 

are present in the vicinity of the monument, they could 

and yield significant quantities to local wells (Seaton and 

Burbey 2005). However, the unconsolidated regolith, 

including saprolite that occurs on top of the bedrock, can 

hold ten to one hundred times more groundwater than 

the crystalline rocks (Sethi et al. 2000). Recharge of 

crystalline aquifers can take thousands of years unless a 

localized breached zone or heavily fractured quartzose 

confining layer is present. Recharge is more rapid for 

shallower, unconfined, surficial aquifers (Sethi et al. 

2000; Seaton and Burbey 2005). Shallower aquifers may 

also be susceptible to threats from pollution sources like

leaking underground storage tanks, septic systems, 

landfills, agricultural fertilizers and pesticides, and 

mining operations (Sethi et al. 2000). Thus the depth of 
6 NPS Geologic Resources Division 

the regolith would be a valuable dataset for resource 

managers. 

Within the monument, groundwater resources can vary 

greatly with the composition of the underlying bedrock. 

In general, the more massive mica gneiss units in the 

Lynchburg Group (geologic map units Zam, CZmy; see 

Map Unit Properties section and Appendix A) have 

deeper soil profiles and would provide better well 

locations where they occur along fractured zones. This 

capacity is due to soil profile characteristics over 

weathered gneissic bedrock have more storage capacity 

than the harder granitic rocks in the Blue Ridge. 

Similarly, the mica-gneiss tends to yield more 

groundwater than the more mica-rich schist, slate, 

phyllite, and the dense amphibole-rich mafic volcanic 

complexes, which form relatively thin, clay-rich soils 

underlying ridges in the area (Conley 1985; DeVore 1998; 

William S. Henika, geologist, Virginia Department of 

Natural Resources, written communication 2009). 

Certain layers of pyrite-rich or graphic-rich schist and 

some of the mafic schist units of the Moneta Gneiss (unit 

Zmg) may contain highly mineralized zones that tend to 

produce groundwater enriched in iron sulfates and,

hypothetically, asbestos from mafic igneous complexes 

(William S. Henika, geologist, Virginia Department of 

Natural Resources, written communication 2009). 

In neighboring Pittsylvania and Halifax counties, 

Legrand (1960) demonstrated how the topographic 

situation of 282 wells in the Piedmont is among the most 

important factors to consider in the location of water 

wells. By subdividing the topography into hillcrests, 

slopes, flats, and draws or saddles, Legrand determined 

that draws and saddles had the highest average yields (42 

gallons per minute [gpm]) whereas hillcrests had the 

lowest at 7 gpm and 70% of wells on flats and 81% of 

wells in draws had sustained yields of greater than 20 

gpm. Geophysical studies since this work have 

conclusively shown a strong relationship between 

bedrock fracture zones and low-lying topographic 

features (flats, draws, and saddles) along linear fracture 

traces (William S. Henika, geologist, Virginia Department 

of Natural Resources, written communication 2009). 

Understanding the bedrock geology of the park is a 

critical resource management concern and can impact 

the understanding and management of groundwater and 

other resources.

Contact the NPS Water Resources Division (Ft. Collins, 

Colorado) for technical assistance with water quality 

issues. The Water Resources Division produced a 

baseline water quality data inventory and analysis report 

(National Park Service 1997).

Erosion

When Booker T. Washington was born on James

Burroughs’s tobacco farm, little was recorded about the 

family’s agricultural practices. Historically, the 

agricultural areas of western Virginia were not developed 

in a sustainable manner (GRI scoping notes 2009). Fields 

were cleared and farmed with little regard for soil 

conservation. Farmers would simply move on to clear 

another patch of ground when the soil was depleted. The 

sloping nature of the landscape and these farming and 

development practices led to severe erosion throughout 

the region. At Booker T. Washington National 

Monument, deep gulleys pointing toward streams 

present on forested slopes record erosion from fields left 

fallow some 80 or more years ago. Vegetation has

gradually reclaimed the eroded slopes (fig. 9) (GRI 

scoping notes 2009).

Soil erosion continues in western Virginia today, 

especially in agricultural areas. With the exception of 

riparian areas along streams, much of the landscape is 

sloped and local creeks are orange with eroded soil 

following rainfall events (GRI scoping notes 2009). Soil 

types such as the clay-rich sandy loams present at the 

monument present moderate to severe erosion hazards 

and limitations on the types of motorized land-use 

practices they will support as defined by soil 

conservationists (Hendrick 1978). A Soils Resources 

Inventory was completed for the park in 2007 (National 

Park Service 2007). According to the monument’s 1999 

General Management Plan (GMP), pastures within park 

boundaries are managed to minimize soil erosion. 

Education and cooperation with surrounding 

landowners in sustainable land-use practices could help 

mitigate the problem of soil erosion in the area. 

As mentioned anecdotally in the fluvial section, park staff 

noticed increased stream flow in recent years; either due 

to climate change-induced severe storm events, 

increased runoff from surrounding development, or 

more likely a combination of the two (GRI scoping notes 

2009). This is causing severe erosion along the stream 

banks within the monument. A few trails run along 

creeks within the monument; there is a potential threat 

to visitor safety if a trail becomes compromised by 

undercutting or washes away during a high flow event 

(fig. 10). In the 1980s and 1990s, the monument 

performed some buttressing and restoration along the 

Jack-O-Lantern Branch to mitigate streambank erosion 

(GRI scoping notes 2009). According to the monument’s 

1999 GMP, erosion forced the relocation of portions of 

the Jack-O-Lantern Branch Trail away from Gills Creek 

and nearby wetlands.

As flow and erosion increase along the monument’s 

streams, channel morphology will naturally change as 

well. Meanders will continue to cut into the banks and 

deposition will increase riparian areas along the opposite 

bank. So far, this change appears to be minor. For some 

stretches, the centerlines of Gills Creek and Jack-OLantern Branch are the legal, surveyed monument 

boundaries. Recent rezoning of some adjacent property 

resulted in a small buffer around Jack-O-Lantern Branch 

(GRI scoping notes 2009).

The formation of social (unofficial) trails and other offtrail activities can strip the landscape of stabilizing 

vegetation causing increases in erosion. A foot trail that 

originated as a fire trail in the late 1970s runs along the 

Jack-O-Lantern Branch. At this time, visitor use of this 

trail does not contribute to local erosion (GRI scoping 

notes 2009).
BOWA Geologic Resources Inventory Report 7

Adjacent Development

The areas surrounding Booker T. Washington National 

Monument is experiencing significant population 

growth. This influx of people is causing the value of farm 

land to increase as urban developers continue to 

purchase large tracts of land for housing and commercial 

centers (GRI scoping notes 2009). As of 2009, offers were 

made to purchase cow pastures on the other side of Gills 

Creek from the monument (GRI scoping notes 2009). 

The increase in land value makes acquisition of 

additional land for the park more difficult. However, 

more problematic are the changes to the landscape 

outside the monument that affect ecosystems within the 

monument. 

Neighboring developers are installing stormwater drain 

systems and retention ponds with overflow channels that 

flow directly into the area’s creeks (GRI scoping notes 

2009). Park staff have noted pulses of sediment load 

increases in monument streams during the construction 

phases of neighboring development (GRI scoping notes 

2009). These increases may be due to heavy flow events 

caused by severe storms, increased impervious surfaces 

associated with development, or a combination of the 

two. Increased sediment load may also be indicative of 

the potential for increased contamination from 

chemicals used in landscaping, associated with 

automobiles, and other human uses. 

Increased demand for groundwater supplies from 

adjacent development may also impact the groundwater 

supply and spring flow within the monument. In 2003-

2004, a neighboring farm was developed into a town 

center. This development involved the drilling of a deep 

well that connected to a water tower system. When this 

system went online, there was a noticeable decrease in 

stream and spring flow within the monument (GRI 

scoping notes 2009). 

According to the 2012 strategic plan report, the 

monument has partnerships with three Chambers of 

Commerce, Eastern National, the Blue Ridge Parkway, 

and the National Park Foundation-African American 

Experience Fund for promoting regional tourism, 

interpretive items, law enforcement support, and special 

events volunteerism, respectively. These and potential 

future partnerships may provide tools and resources 

necessary to mitigate issues concerning surrounding 

development. Educating the public is an invaluable tool 

to increase awareness of the potential problems 

associated with surrounding development. 

Seismicity

Active seismicity is not commonly characteristic of the 

Piedmont or Blue Ridge of Virginia; however, several 

minor, but noticeable earthquakes occur in the region 

every few years (GRI scoping notes 2009). In 1924, earth 

tremors in Roanoke, Virginia were severe enough to cut 

water pipes (Woodward 1932). Several years ago an 

earthquake near Amherst, Virginia (some 100 km [60 mi]

away) caused noticeable ground shaking at the 

monument. At this time, no cultural resources are 

considered threatened by seismicity within the 

monument (GRI scoping notes 2009). Visitor use 

facilities and park infrastructure, such as foundations,

could be cracked or shifted during earthquakes. 

The effects of earthquakes in the Blue Ridge and 

Piedmont are felt over relatively broad areas because the 

hard, crystalline basement rocks transmit seismic waves 

effectively (Sethi et al. 2000). Even moderate seismic 

shaking can trigger mass wasting (Gilliam and Henika 

1999). Debris flows, or mixtures of soil, rocks, and water 

that move downhill as fast-moving landslides, are not 

uncommon in west-central Virginia following intense 

storms and can be triggered by an earthquake. In 

Virginia, debris flows can be thick enough to carry away 

trees, cars, and buildings. They typically start on steep 

slopes of about 30 degrees or more, accelerate to 56 

km/hr (35 mi/hr) or more, and deposit thick lobes of 

unsorted material on flatter ground, burying whatever 

lies in its path (Sethi et al. 2000). Areas with thick, loose 

soils (such as those developed on granitic gneisses that 

are rich in quartz sand and mud) may be likely to move 

downhill during heavy rainfall events and slides may be 

acerbated during seismic shaking.

Seeps and Springs

Seeps and springs occur throughout the monument

(fig. 11). In the monument, springs emerge out of the 

ground, often as wet, swampy areas. One spring emerges 

at a big, flat rock, possibly hinting at the geologic 

structure controlling its location. Park staff have not 

noted immediate increases in spring flow following 

precipitation events, which may indicate that the springs 

are deep-sourced. Recent drilling associated with a 2009 

addition to the monument visitor center (circa 1965) 

went down approximately 11 m (35 ft) before it hit the 

water table (GRI scoping notes 2009). In the monument,

surface water percolates down through deep regolith to 

recharge the underlying aquifer.

Shrink-and-Swell Clays

The clay-rich soil within the monument may contain 

shrink-and-swell clays that could undermine building, 

road, trail, and other infrastructure foundations. 

Similarly, these slippery clays can affect visitor trails,

causing them to be unsafe in wet conditions. These clays 

swell when saturated with water and shrink when dry 

causing moderate to extreme volume changes. 

Regionally, shrink-and-swell clays arise from weathering 

of amphibolite units (Mark Carter, geologist, U.S. 

Geological Survey, written communication 2009). 

Amphibolite (geologic map unit CZmi) occurs within 

Booker T. Washington National Monument. Knowledge 

of the extent of this unit correlated with park 

infrastructure and visitor use areas could help mitgate

potential problems associated with shrink-and-swell 

clays. 
8 NPS Geologic Resources Division 

Figure 4: Rocks within Gills Creek, which is part of the monument’s west boundary and flows through the monument. The stream 

bottom varies from a bedrock channel to gravel and other sediment. Within the monument, Gills Creek primarily crosses rocks mapped 

as Ashe Formation (geologic map unit Zam). View is from the east. Photograph courtesy of Booker T. Washington National Monument 

staff. 

Figure 5: Jack-O-Lantern Branch originates within the monument and forms the east and south boundary. The right side of the stream 

bank faces east at the bottom of an east-facing wooded slope. Photograph courtesy of Booker T. Washington National Monument staff.
BOWA Geologic Resources Inventory Report 9

Figure 6: The bedrock channel of Jack-O-Lantern Branch at Booker T. Washington National Monument. Jack-O-Lantern Branch crosses 

rocks mapped as amphibolite (geologic map unit CZmi) and Ashe Formation (Zam). Photograph has the same viewpoint as figure 5. 

Photograph courtesy of Booker T. Washington National Monument staff.

Figure 7: Gravel and finer sediments within a meander along Jack-O-Lantern Branch. The sediments form a mini point-bar and are on the 

inside of the meander loop. Photograph courtesy of Booker T. Washington National Monument staff.
10 NPS Geologic Resources Division 

Figure 8: Jack-O-Lantern Branch flowing west with increased flow and volume after being joined by two unnamed tributaries. 

Anthropogenic features including a fence, have created a temporary dam, artificial pool, and small waterfall. View is from the northern 

side of the stream. Photograph courtesy of Booker T. Washington National Monument staff.

Figure 9: Weathered outcrop on eroded, reforested landscape within Booker T. Washington National Monument. Such bedrock 

exposures are rare in the monument area and contain important information about the local geologic history and structures. 

Photograph is from an area southwest of monument headquarters and courtesy of Booker T. Washington National Monument staff.
BOWA Geologic Resources Inventory Report 11

Figure 10: Undercut slope along a small, unnamed tributary that originates from a spring in the wooded area of the monument 

southwest of headquarters. Stream flows southwest to Gills Creek. Note the deep red soil color. View is toward the northwest. 

Photograph courtesy of Booker T. Washington National Monument staff.

Figure 11: Jack-O-Lantern Branch within 100 m (300 ft) of its confluence with Gills Creek. Note the presence of a smaller, spring-fed 

tributary in the middle of the image. In this stretch the stream has a wide flood plain with eroded areas and sediments within the 

channel. View is from the north. Photograph courtesy of Booker T. Washington National Monument staff.
12 NPS Geologic Resources Division 

Geologic Features and Processes

This section describes the most prominent and distinctive geologic features and processes 

in Booker T. Washington National Monument.

Geologic Influences on History

The Blue Ridge Mountains had an impact on settlement 

patterns in Virginia. Early English colonists preferred the 

gentler terrain of the Piedmont and Coastal Plain 

whereas Scotch-Irish settlers felt more comfortable in 

the highlands (Sethi et al. 2000). Their settlement 

patterns in combination with natural geologic processes 

of weathering and erosion shaped the lands in the 

monument region (De Vore 1998). 

Discoveries of minerals often spur population surges as 

people, eager to take advantage of quick economic gain, 

move to boom towns. Iron deposits (red hematite, and 

iron-rich clays) were among the first mineral resources 

developed in the region. Iron mineralization in quartzite 

breccias and as limonite nodules in deep orange residual 

clay soils provided the primary source of ore (Gilliam 

and Henika 1999). The old Back Creek furnace, located 

about 10 km (6 mi) south of Roanoke; the old Catawba 

furnace (ca. 1820) operated near Haymakertown; and the 

Cloverdale furnace (active between 1830 and 1849) 

reflected the local accessibility of ores (Woodward 

1932). These types of small-scale operations may have 

provided tool material to rural farmers such as the 

Burroughs. 

According to Woodward (1932), the Precambrian rocks 

of the greater Roanoke area contain nelsonite (a source 

of ilmenite and apatite), barite (mined near Thaxton in 

Bedford County), quartz veins with small amounts of 

placer gold, and residual clays (source of kaolin). 

Prospects for silver, nickel, cobalt, arsenic, copper, 

graphite, and talc yielded little of commercial value 

(Woodward 1932). Iron mining and the railroad were the 

primary drivers of the population boom of the late 19th

century. 

Access to an abundant, reliable source of water strongly 

influenced the selection and development of farmland. 

Gills Creek and Jack-O-Lantern Branch played major 

roles in the farming practices of the Burroughs family. In 

2000, investigators recognized at least one old dam along 

a colonial road bed located just upstream from the 

southwestern monument boundary (William S. Henika, 

geologist, Virginia Department of Natural Resources, 

written communication 2009). Springs occur where 

groundwater is controlled by the structure of the 

underlying rocks. Geologic features such as faults, folds, 

and resistant layers often focus the location of springs. 

Several springs and seeps occur at Booker T. Washington 

National Monument. These likely supplied some water 

to the farming efforts of the Burroughs family. 

Booker T. Washington National Monument sits near the 

transition between the western Piedmont and the Blue 

Ridge. It is on the fringe of the tobacco growing area 

(southern tobacco belt) and the mix of flora and fauna at 

the monument reflect this transition (De Vore 1998; GRI 

scoping notes 2009). In the mid-1850s, tobacco was the 

cash crop at the Burroughs’ farm. In the interest of being 

self-sufficient, sustenance crops were also raised. 

Regionally, red and yellow podzolic soils are developed 

on rocks of the region characterized by a deep saprolite 

forming the C soil horizon (Hunt 1972; Conley 1985). 

Locally, the depth to bedrock is variable from 2 to 18 m 

(6 to 60 ft) (William S. Henika, geologist, Virginia 

Department of Natural Resources, written 

communication 2009). The soils at Booker T. 

Washington National Monument are well-drained, 

bright red in color, enriched with iron, and high in clay 

content (clayey-sandy loam soils) (fig. 10) (De Vore 1998; 

GRI scoping notes 2009). For more information 

regarding soils in the monument refer to the 

National Park Service Soil Survey database (2007). This 

type of soil can arise from deep weathering of 

amphibolite rocks such as those beneath the monument 

(geologic map unit CZmi). Amphibolites are unstable 

under surface chemical weathering conditions and tend 

to form thin soils which protect the unstable rocks from 

further weathering. Soils underlain by quartz- and 

feldspar-bearing gneisses and gabbro-type rocks readily 

develop thick (as much as 45 m [150 ft]) saprolite layers 

(Conley 1985). Some of the soils within the monument 

are very deep, however, formed as residuum weathered 

from felsic crystalline rocks such as mica schists and 

gneisses (De Vore 1998). 

Bedrock outcrops are not common in the monument. 

Where present they occur as ledges in streams (fig. 12). 

Rocks derived from weathering and mass wasting litter 

the landscape (fig. 13). Early settlers piled larger rocks 

into irregular mounds and straight lines that run through 

the woods of the monument (fig. 14). The purpose of 

these stone lines is unknown, but may have been to 

delineate different fields, property lines, or to act as 

fences. Local rocks also likely formed the source for 

building foundations and chimneys and were probably 

reused and recycled during the long history at the 

monument. An old stone foundation for a barn or 

tobacco building exists within the monument. Evidence 

from old stonewalls in a dam structure near the 

monument boundary suggests the rock was mined; 

however, no local quarry sites have been identified 

(William S. Henika, geologist, Virginia Department of 

Natural Resources, written communication 2009). Local 

stones probably were also used for roadbeds. Gravel 

from local stream deposits in meanders along tributaries 

to Gills Creek would have provided gravel sources for 

roadways across the farm site (William S. Henika, 

geologist, Virginia Department of Natural Resources, 

written communication 2009). Stream bottom outcrops 

of talc-tremolite schist within 200 m (650 ft) of the 
BOWA Geologic Resources Inventory Report 13

southeastern monument boundary corner may have 

provided quarry stones for hearths (William S. Henika, 

geologist, Virginia Department of Natural Resources, 

written communication 2009). Most park buildings have 

dry rubble foundations of large, flat gray rocks installed 

in the 1970s. Split rail fences within the monument have 

joints atop rocks to keep the wood from rotting on the 

ground. Old cemeteries (one dates back to the 1820s), 

surveyed with remote sensing in 1998, are marked with 

fieldstones as headstones and footstones (De Vore 1998). 

The source of these rocks is unknown (GRI scoping 

notes 2009). 

Weathered Regolith

Knowledge of the composition, thickness, and extent of 

surficial deposits is important for planning, construction, 

restoration, and groundwater development throughout 

the Booker T. Washington National Monument (Arnato 

1973). More than 95% of the local bedrock is covered by 

interrelated deposits of residual soil, alluvium, and 

colluvium ranging in thickness from a few centimeters to 

more than 30 m (100 ft) (Arnato 1973). The bedrock 

underlying the monument is deeply weathered 

producing a thick overburden of saprolite, soil, and other 

residual regolith. As mentioned under “Geologic 

Influences on History”, the soils at the monument are 

clay rich atop a thick layer of saprolite, reflecting the 

residual nature of their formation. Certain resistant 

minerals such as quartz and staurolite persist in the soils 

as the final unweathered portion of the bedrock. Quartz 

is present as rounded clasts and angular chunks locally. 

The well-rounded clasts are likely derived from the Blue 

Ridge rocks to the northwest that were deposited along 

ancient fluvial terraces (William S. Henika, geologist, 

Virginia Department of Natural Resources, written 

communication 2009). The angular quartz rock and 

lenticular veins (injected into the gneissic bedrock during 

deformation and metamorphism from 200 to 460 million 

years ago) form resistant ledges cutting deeply weathered 

bedrock (saprolite) throughout the map area (Henika 

1997; William S. Henika, geologist, Virginia Department 

of Natural Resources, written communication 2009). At 

the monument, quartz rocks occur at the surface. Nearby 

Fairy Stone State Park is famous for the accumulation of 

the cross-shaped metamorphic mineral staurolite crystals 

(“fairy stones”) (GRI scoping notes 2009). Staurolite only 

forms in the relatively high temperature and pressure 

environments associated with regional metamorphism 

from ancient orogenies.

Soil conservation plans prepared by the U.S. Department 

of Agriculture Soil Conservation Service identified and 

mapped, nine different soil types: Toccoa Fine Sandy 

Loam, Wilkes Pine Sandy Loam (two slope ranges), 

Madison Fine Sandy Loam (three slope ranges), Cullen 

clay loam, and Poindexter Pine Sandy Loam (Hendrick 

1978). Many of these soils have firm clay subsoil layers 

and are moderately drained. Remnant clasts include 

micas and quartz (Hendrick 1978). A thorough review of 

soil patterns and development at Booker T. Washington 

National Monument is beyond the scope of this report. 

Resource managers are encouraged to consult the Soil 

Resources Inventory Program of the NPS Geologic 

Resources Division; a soil database was produced by the 

Soil Resources Inventory Program (National Park 

Service 2007).

Figure 12: Bedrock ledges along Jack-O-Lantern Branch. The view is toward the east. Photograph courtesy of Booker T. Washington National 

Monument staff.
14 NPS Geologic Resources Division 

Figure 13: “Whale Rock” along the western-flowing Jack-O-Lantern Branch. Many large boulders exist along streams within the monument 

area. Photograph courtesy of Booker T. Washington National Monument staff.

Figure 14: Rock piles on west-facing slopes in the forested area southwest of the monument headquarters. Rocks were piled as they were 

cleared from areas previously used for agricultural purposes. Many such piles are linear and oriented to one another all along the slope of the 

woods. Photograph courtesy of Booker T. Washington National Monument staff.
BOWA Geologic Resources Inventory Report 15

Map Unit Properties

This section identifies characteristics of map units that appear on the Geologic Resources 

Inventory digital geologic map of Booker T. Washington National Monument. The

accompanying table is highly generalized and for background purposes only. Grounddisturbing activities should not be permitted or denied on the basis of information in this

table. 

Geologic maps facilitate an understanding of Earth, its 

processes, and the geologic history responsible for its 

formation. Hence, the geologic map for Booker T. 

Washington National Monument provided information 

for the “Geologic Issues,” “Geologic Features and 

Processes,” and “Geologic History” sections of this 

report. Geologic maps are two-dimensional 

representations of complex three-dimensional 

relationships; their color coding illustrates the 

distribution of rocks and unconsolidated deposits. Bold 

lines that cross or separate the color patterns mark 

structures such as faults and folds. Point symbols 

indicate features such as dipping strata, sample localities, 

mines, wells, and cave openings. 

Incorporation of geologic data into a Geographic 

Information System (GIS) increases the usefulness of 

geologic maps by revealing the spatial relationships 

among geologic features, other natural resources, and

anthropogenic features. Geologic maps are indicators of 

water resources because they show which rock units are 

potential aquifers and are useful for finding seeps and 

springs. Geologic maps are not soil maps, and do not 

show soil types, but they do show parent material—a key 

factor in soil formation. Furthermore, resource managers 

have used geologic maps to make connections between 

geology and biology; for instance, geologic maps have 

served as tools for locating sensitive, threatened, and 

endangered plant species, which may prefer a particular 

rock unit. 

Although geologic maps do not show where earthquakes 

will occur, the presence of a fault indicates past 

movement and possible future seismic activity. Similarly, 

map units show areas that have been susceptible to 

hazards such as landslides, rockfalls, and volcanic 

eruptions. Geologic maps do not show archaeological or 

cultural resources, but past peoples may have inhabited 

or been influenced by depicted geomorphic features. For 

example, alluvial terraces may have been preferred use 

areas and formerly inhabited alcoves may occur at the 

contact between two rock units.

The geologic units listed in the following table 

correspond to the accompanying digital geologic data. 

Map units are listed in the table from youngest to oldest. 

Please refer to the geologic timescale (fig. 15) for the age 

associated with each time period. The table highlights 

characteristics of map units such as: susceptibility to 

erosion and hazards; the occurrence of paleontological 

resources (fossils), cultural resources, mineral resources, 

and caves or karst; and suitability as habitat or for 

recreational use. Some information on the table is

conjectural and meant to serve as suggestions for further 

investigation.

The GRI digital geologic maps reproduce essential 

elements of the source maps including the unit 

descriptions, legend, map notes, graphics, and report. 

The following references are the sources for the GRI 

digital geologic data for Booker T. Washington National 

Monument: 

Henika, W.S. 1997. Geologic map of the Roanoke 30 x 60 

minute quadrangle. Scale 1:100,000. Publication 148. 

Richmond, VA: Virginia Division of Mineral 

Resources. 

Elizabeth V. M. C., D. Sheres, and C. R. Berquist, Jr. 

2001. Digital spatial data for a portion of the Roanoke, 

VA 1:100,000 30x60 minute quadrangle - Hardy, 

Goodview, Redwood, Moneta SW 7.5-minute 

quadrangles. Scale 1:100,000. Unpublished. Richmond, 

VA: Virginia Division of Mineral Resources.

The GRI team implements a geology-GIS data model 

that standardizes map deliverables. This data model 

dictates GIS data structure including data layer 

architecture, feature attribution, and data relationships 

within ESRI ArcGIS software, and increases the overall 

utility of the data. GRI digital geologic map products 

include data in ESRI personal geodatabase, shapefile, 

and coverage GIS formats, layer files with feature 

symbology, Federal Geographic Data Committee 

(FGDC)-compliant metadata, a Windows help file that 

contains all of the ancillary map information and 

graphics, and an ESRI ArcMap map document file that 

easily displays the map.

GRI digital geologic data are included on the attached 

CD and are available through the NPS Data Store 

(http://science.nature.nps.gov/nrdata/). Data will be 

available on the Natural Resource Information Portal 

when the portal goes online. As of August 2010, access is 

limited to NPS computers at http://nrinfo/Home.mvc.
BOWA Geologic Resources Inventory Report 16

Map Unit Properties Table: Booker T. Washington National Monument

Colored rows indicate geologic units mapped within Booker T. Washington National Monument

Age Unit Name

(Symbol) Features and Detailed Geologic Description Erosion Resistance Suitability for Infrastructure Hazards Cultural Resources Karst Mineral Occurrence Habitat Geologic Significance and Miscellaneous Notes

JURASSIC

Igneous dikes 

and sills

(Jd)

Unit contains fine- to coarse-grained extrusive basalt, and 

intrusive diabase and gabbro with dark-greenish-black to black 

appearance and outcrops. Degree of visible crystallization ranges 

from aphanitic (indistinguishable), intergranular, subophitic to 

hypidiomorphic-granular. Chilled margins are common in 

outcrop exposures.

High

Unit is limited in extent, but could 

weather to produce shrink-and-swell 

clays.

Where unit is more 

resistant that surrounding 

rock and exposed on a 

slope, rockfall potential 

exists. 

Glassy pieces of unit 

may have provided 

tool material.

None. Plagioclase, olivine.

Unit may weather 

to produce ironand magnesiumrich soils.

Unit records the extensional 

tectonic environment of the 

eastern margin of North 

American throughout the 

mid-Mesozoic.

PALEOZOIC

Mylonite gneiss 

(PZZmy)

Unit is part of the Blue Ridge thrust sheet and contains dark-gray 

to dark-grayish-green protomylonite (least deformed) and 

mylonite as well as light-gray, siliceous ultramylonite (most 

deformed) and micaceous phyllonite. Zones of this unit are 3-6 m 

(10-20 ft) wide and may be poorly- to well-foliated. 

Moderate

Unit is associated with deformation 

zones and will act as zones of 

anisotropy within country rock 

exposures.

Heterogeneous nature of 

unit may render it unstable 

on exposed, weathered 

slopes.

None documented. None.

Unit is highly 

disseminated, 

recrystallized country 

rock.

None documented.

Unit developed during 

Paleozoic deformation of 

Middle to Late Proterozoic 

country (basement) rock 

units.

CAMBRIAN

Unicoi 

Formation

(Cu)

Unit is part of the Blue Ridge thrust sheet and the Chilhowee 

Group. Total thickness ranges from 300 to 425 m (1,000 to

1,400 ft). The upper portion of this unit contains quartz pebble 

conglomerate that appears greenish-gray, purple, and white in 

outcrops of three to five thick-bedded ledges. Some coarsegrained, purplish-gray ferruginous sandstones present locally. The 

lower portion of the unit contains metasilstone and meta-arkose 

that appears pinkish gray to dark-greenish-gray. Lower beds are 

fine- to coarse-grained, locally contain conglomerate and exhibits 

spheroidal weathering. 

High

Unit would form a strong 

foundational base unless highly 

fractured, weathered, and/or 

exposed on a steep slope.

Unit may be prone to 

rockfall and topple where 

undercut by erosion and 

exposed on ledges and 

slopes.

Where unit forms 

ledges and overhangs, 

American Indians may 

have taken advantage 

of natural shelters.

None.

Ferruginous sandstones 

were locally prospected 

for iron; conglomerate.

Unit forms 

prominent ledges 

that may provide 

nesting habitat.

Unit is part of the Lovingston 

massif and has gradational 

contacts with 

metamorphosed regolith 

formed on older, Middle 

Proterozoic gneiss. Unit 

contains igneous stratigraphy 

that indicates several volcanic 

centers active during the 

Cambrian.

CAMBRIAN-LATE PROTEROZOIC

Amphibolite 

(CZmi)

Unit is part of the Lynchburg Group and the Fries thrust sheet. 

Amphibolite appears dark-greenish to black with coarse 

granoblastic textures. Amphibolite grades into greenish-gray, finegrained, chlorite-amphibole schist, ultramafic schist, or soapstone 

in metamorphosed plutons. Unit crops out in Booker T. 

Washington National Monument.

Moderate

Heavily altered zones may be points 

of weakness in units. Due to high 

shrink and swell clay potential, avoid 

development of buildings and septic 

fields on this unit. 

Lenses of resistant rocks in 

schistose layers may be 

susceptible to block and 

rockfall. Abundant shrink 

and swell clay potential 

exists for weathered 

portions of this unit.

Soapstone may have 

provided trade 

material. 

None. Soapstone, chlorite, 

amphibole.

Unit may weather 

to produce 

calcium-, iron-, and 

magnesium-rich 

soils.

Unit is part of the Lovingston 

massif and contains a record 

of deformation within the 

Fries thrust sheet; igneous 

intrusions; and regional 

metamorphism. 

Laminated mica 

gneiss 

(metagraywacke) 

(CZmy);

Unit is part of the Alligator Back Formation, Lynchburg Group, 

and Fries thrust sheet and contains medium- to light-gray mica 

schist, quartzite, calc-gneiss, graphitic phyllite, marble, bluequartz-granule and metaconglomerate beds. Textures range from 

fine- to medium-grained. Dark-greenish-gray actinolite schist 

occurs in thin partings throughout the unit. Unit crops out in 

Booker T. Washington National Monument.

Moderate to high 

for quartzite

Heterogeneous nature of unit may 

render it unstable on slopes.

Unit may be prone to 

landsliding where undercut 

on steep slopes and heavily 

fractured.

None documented.

Marble may be 

prone to dissolution, 

but too localized to 

be problematic.

Marble, quartzite, 

actinolite. None documented.

Unit is part of the Lovingston 

massif and represents a mixed 

depositional environment

and contains record of 

regional metamorphism of 

the Fries thrust sheet. The 

Alligator Back Formation 

contains an ophiolite-bearing 

metasedimentary suite.

Actinolite schist 

(CZas)

Unit is part of the Lynchburg Group and consists of darkgreenish-gray to light-yellowish-green, quartz-epidote granofels 

layered with tuffaceous metasandstone and thin quartz-mica 

phyllite, quartzite, metagraywacke, talc-silicate beds, and local 

lens-shaped pods of white and pink marble. 

Moderate to high 

for quartzite

Schistose nature of portions of this 

unit may be unstable for heavy 

development. Avoid especially 

micaceous and/or weathered areas. 

If unit is highly weathered 

and exposed on a slope, 

landslide potential exists. 

Radon gas can develop 

from this unit.

Residual clay from 

this unit may have 

been used in local 

brick making 

operations.

Marble may be 

prone to dissolution, 

but too localized to 

be problematic.

Marble, talc.

Unit may weather 

to produce 

calcium-rich soils

Unit is part of the Lovingston 

massif and is correlative to 

off-shore equivalents of 

metabasalt, metarhyolite, and 

arkose of the Catoctin 

Formation to the northeast, 

deposited after the Grenville 

Orogeny.
Colored rows indicate geologic units mapped within Booker T. Washington National Monument

BOWA Geologic Resources Inventory Report 17

Age Unit Name

(Symbol) Features and Detailed Geologic Description Erosion Resistance Suitability for Infrastructure Hazards Cultural Resources Karst Mineral Occurrence Habitat Geologic Significance and Miscellaneous Notes

LATE PROTEROZOIC

Ashe Formation 

(Zam)

Unit is part of the Lynchburg Group and contains biotite gneiss 

and schist with medium- to light-gray appearance in outcrop and 

coarse- to very coarse-grained textures. Unit is nearly 

structureless. Conglomeratic layers contain feldspar, quartz, and 

granitic clasts, and grades upward into medium- to fine-grained, 

two-mica plagioclase gneiss interbedded with mica schist. Unit 

crops out in Booker T. Washington National Monument.

Moderately high

Foliation and schistosity of unit may 

render it susceptible to mass wasting 

processes of exposed on slope 

parallel to regional fabric.

Unit may be prone to 

blockfall and topple where 

resistant conglomerates are 

undercut on slopes. 

Metavolcanic rocks can be 

a source of radon gas.

None documented. None. ‘Salt and pepper’ gneiss, 

feldspar, quartz, mica. None documented.

Unit is part of the Lovingston

massif. Conglomeratic layers 

may correlate with Rockfish 

Conglomerate to the 

northeast. Unit is 

intergradational along strike 

with metavolcanic rocks of an 

Iapetan rift basin (Zmg).

Granitic gneiss 

(Zgd)

Unit is part of the Lynchburg Group and contains medium-gray or 

pinkish-gray, medium- to coarse-grained biotite or hornblende 

granitoid. Granitoid is poorly foliated to massive and is 

gradational with medium-gray, fine- to medium-grained mylonite 

gneiss at sheared pluton contacts.

Moderately high

Suitable for most forms of 

development unless highly 

weathered and/or fractured.

Unit may pose blockfall or 

topple hazard on slopes. 

Radon gas can develop 

from this unit.

None documented. None. Biotite, hornblende. None documented.

Unit is part of the Lovingston

massif. Unit records 

deformation accompanying 

igneous intrusions.

Moneta Gneiss 

(Zmg)

Unit is part of the Lynchburg Group and consists of black and 

white banded gneiss with medium- to fine-grained textures. 

Weathered outcrops appear olive-brown to yellowish-green. 

Locally, dark-greenish-gray to black and white amphibolite; lightgray quartz-feldspar gneiss; feldspathic metaconglomerate; and 

mica schist are interlayered with the gneiss. Abundant granitic 

dikes and sills present locally. 

Moderately high

Schistose, and highly foliated units 

should be avoided for heavy 

development due to inherent 

weakness. Heavily deformed and/or 

weathered areas are also unsuitable 

and unstable in deep excavated cuts.

May be susceptible to mass 

wasting if exposed on 

slope. Weathered material 

(saprolite) is susceptible to 

severe erosion and 

sedimentation problems if 

exposed.

Pegmatites were 

mined in the MonetaBells feldspar mining 

district of Bedford 

County.

None. Mica, pegmatite 

minerals, feldspar.

Unit may weather 

to produce clayrich soils.

Unit is part of the Lovingston 

massif. Unit correlates 

gradationally with 

conglomeratic biotite gneiss 

and schist of the Ashe 

Formation.

MIDDLE PROTEROZOIC

Layered gneiss 

and granulite 

(Ypg)

Unit is part of the Blue Ridge thrust sheet and Lynchburg Group. 

Unit is composed of massive granofels that appear medium- to 

dark-greenish-gray in outcrop with fine- to medium-grained 

textures. Unit also contains layered, garnet-pyroxene-quartzfeldspar rock surrounding plutons and as xenoliths in large 

intrusive suites. Near deformed areas, unit grades into greenishgray mylonite and mylonite gneiss.

Moderate Heterogeneous nature of unit may 

render it unstable on slopes.

Unit may be prone to 

landsliding where undercut 

on steep slopes and heavily 

fractured.

Garnets may have 

been source for 

abrasives or trade 

material.

None. Garnet, pyroxene.

Unit may weather 

to iron-, 

magnesium-, and 

calcium-rich soils.

Unit is part of the Pedlar

massif. Unit occurs as 

xenoliths in Grenville and 

Iapetan intrusive suites. Unit 

is correlative with the Lady 

Slipper granulite gneiss unit, 

with zircon age of 1130 Ma.

Augen and flaser 

gneiss

(Yma)

Unit is part of the Lynchburg Group and the Fries thrust sheet. 

Unit is light- to medium-gray, with mesoscopic layers and 

medium- to coarse grained textures. Dominant rock type is 

muscovite-biotite gneiss with lesser amounts of polycrystalline 

quartz-feldspar augen with mica-rich, schistose matrix.

Moderate

Schistose layers may weather 

preferentially causing instability for 

heavy development.

Weathering along schistose 

layers may render portions 

of this unit unstable and 

prone to rockfall.

None documented. None. Mica, augen.

Unit may weather 

to produce clayrich soils.

Unit is part of the Lovingston 

massif. Unit contains record 

of deformation and 

metamorphism within the 

Fries thrust sheet.

Biotite-granitoid 

gneiss

(Ybg)

Unit is part of the Lynchburg and Fries thrust sheet and consists of 

medium- to dark-gray, medium- to coarse-grained gneiss with 

prominent relict subhedral to augen-shaped monocrystalline alkali 

feldspar crystals.

Moderately high Suitable for most development unless 

highly weathered and/or fractured. 

Preferential weathering of 

less resistant layers may 

increase likelihood of 

spalling when unit is 

exposed on a slope. 

Phenocrysts may have 

provided trade 

material.

None. Alkali feldspar 

phenocrysts.

Unit may weather 

to produce clayrich soils.

Unit is part of the Lovingston 

massif.
Colored rows indicate geologic units mapped within Booker T. Washington National Monument

BOWA Geologic Resources Inventory Report 18

Age Unit Name

(Symbol) Features and Detailed Geologic Description Erosion Resistance Suitability for Infrastructure Hazards Cultural Resources Karst Mineral Occurrence Habitat Geologic Significance and Miscellaneous Notes

MIDDLE PROTEROZOIC

Charnockite

(Yc)

Unit is part of the Lynchburg and Fries thrust sheet and consists of 

dusky-green, medium- to coarse-grained granitoid rock. In 

outcrop, this unit may appear massive to foliated and may be 

granular to porphyritic.

Moderately high

Suitable for most development unless 

highly weathered and/or fractured. 

Avoid weathered areas for basements 

and foundations due to potential 

radon problems.

May be susceptible to mass 

wasting if exposed on 

slope.

None documented. None. Orthopyroxene. None documented.

Unit is part of the Lovingston 

massif. Unit includes the 

southeastern part of the Peaks 

of Otter Charnockite Suite 

and charnockite of the 

Turkey Mountain Suite.

Biotite granitoid 

(Yhm)

Unit is part of the Lynchburg and Fries thrust sheet and contains 

medium- to dark-gray, coarse-grained to porphyritic gneiss that 

grades into dark-gray, well-foliated biotite-granitoid gneiss, 

protomylonite (less deformed) and mylonite (more deformed) 

gneiss.

Moderately high

Unit is locally associated with 

deformation zones and will act as 

zones of anisotropy within country 

rock exposures.

Weathered and fractured 

portions of this unit pose 

blockfall hazard especially 

if exposed on a slope.

None documented. None. Biotite. None documented.

Unit is part of the Lovingston 

massif. Unit includes the 

Horsepen Mountain Suite 

and the biotite granitoid of 

the Turkey Mountain Suite.

Biotite granofels 

and gneiss

(Ygb)

Unit is part of the Lynchburg and Fries thrust sheet and consists of 

light-gray to dark-grayish-green amphibolite with medium- to 

coarse-grained, banded textures. Unit locally grades into relict 

granulite assemblages. Green mylonite is common within this unit 

along major shear zones.

Moderate

Unit is locally associated with major 

shear zones and will act as zones of 

anisotropy within country rock 

exposures.

Weathered and fractured 

portions of this unit pose 

blockfall hazard.

Garnets may have 

been source for 

abrasives or trade 

material.

None.

Garnet, hornblende, 

uralitic amphibole, 

opaque minerals.

None documented.

Unit is part of the Lovingston 

massif. Unit contains record 

of early metamorphic 

conditions overprinted by 

later, lower grade 

metamorphism. Shear zones 

within this unit contain 

record of deformation events.
BOWA Geologic Resources Inventory Report 19

Geologic History

This section describes the rocks and unconsolidated deposits that appear on the digital 

geologic map of Booker T. Washington National Monument, the environment in which 

those units were deposited, and the timing of geologic events that created the present 

landscape.

The geologic history of any region is interpreted from all 

the geologic features present in the landscape. In the area 

of Booker T. Washington National Monument, the 

succession of ancient events is recorded primarily in the 

rocks and topographic expression. Each rock formation, 

soil, and feature of the landscape provide evidence which 

may be interpreted in terms of the sequence of processes 

which produced the features. This must all be taken into 

account to decipher the successive stages of geologic 

history.

Precambrian and Early Paleozoic Era: Ancient Mountain 

Building, Rifting, and Iapetus Ocean Formation

The recorded geologic history of the Appalachian 

Mountains begins in the Mesoproterozoic Era (figs. 15, 

16, and 17A), during the Grenville Orogeny about one 

billion years ago. At that time, Rodinia, a supercontinent, 

formed and incorporated most of the continental crust in 

existence, including the craton of North America and 

Africa. The supercontinent separated into several pieces 

one of which is known as Laurentia or ancestral North 

America. The sedimentation, deformation, plutonism 

(the intrusion of igneous rocks), and volcanism are 

manifested in the metamorphic gneisses in the core of 

the modern Blue Ridge Mountains just west of Booker T. 

Washington National Monument (Harris et al. 1997). 

Geologic units of the Blue Ridge thrust sheet include 

charnockites, nelsonite, layered gneiss and granulite 

(Henika 1997). These and other rocks were deposited 

over a period of 100 million years and are more than a 

billion years old, making them among the oldest rocks 

from this region. They form a basement upon which all 

other rocks of the Appalachians were deposited (Sethi et 

al. 2000; Southworth et al. 2001). Rocks from this time in 

the vicinity of the monument include augen and flaser 

gneiss, as well as biotite-granitoid gneiss (geologic map 

units Yma and Ybg) (Henika 1997). 

In the late Proterozoic (fig. 17B), roughly 750 to 600 

million years ago, rifting started in the area. The 

supercontinent broke up intermittently and a sea basin 

formed that eventually became the Iapetus Ocean. The 

Iapetus (named for Iapetus; in Greek mythology the 

father of Atlas, namesake of the Atlantic Ocean) was one 

of several proto-Atlantic ocean basins that closed 

episodically during the Paleozoic. Other basins included 

the Theic and Rheic oceans (named for other Titans in 

Greek mythology) (Horton and Zullo 1991; Nance and 

Linnemann 2008). The Iapetus basin collected many of 

the sediments and volcanic rocks that would eventually 

form the Appalachian Mountains and Piedmont Plateau. 

Mixed sedimentary and volcanic rocks (now 

metamorphosed) such as laminated mica gneiss of the 

Alligator Back Formation, biotite gneiss and schist of the 

Ashe Formation, and amphibolite that occur in both 

units in the vicinity of Booker T. Washington National 

Monument, accumulated during this time (units CZmy 

and Zam) (Conley 1978; Henika 1997). The Ashe 

Formation has coarse-grained, conglomeratic beds that 

accumulated along the margin of the Iapetan rift basin 

intergrading along strike with metavolcanic rocks 

(Moneta gneiss) (Henika 1997). Pebbly greywacke and 

conglomerates were covered by turbidite deposits 

eastward, and then mud and limestone as the basin 

continued to subside (Conley 1978). 

As a result of rifting flood basalts and other igneous 

rocks such as diabase and rhyolite accumulated on the 

North American continent. These igneous rocks were 

intruded through cracks in the granitic gneisses of the 

Blue Ridge core and extruded onto the land surface 

during the breakup of the Rodinian continental land 

mass (Southworth et al. 2001). The weathered and 

altered remains of the early flood basalts are preserved in 

the Catoctin Formation, located to the north of Booker 

T. Washington National Monument (Mixon et al. 2000).

The Alligator Back Formation (laminated mica gneiss, 

actinolite schist [metabasalt], and metagraywacke) is 

likely the offshore equivalent of the metabasalt, 

metarhyolite, and arksose of the Catoctin Formation 

(Henika 1997). The garnet-bearing hornblende gneiss, 

mica gneiss, and schist with coarse-grained amphibolite 

layers exposed as ledges along creeks within the 

monument were possibly part of a complex igneous 

volcanic and plutonic suite intruded into mixed strata 

within the rift (Henika 1997; William S. Henika, 

geologist, Virginia Department of Natural Resources, 

written communication 2009). In general, rocks of the 

Lynchburg Group overlie the basement on the 

southeastern limb of the Blue Ridge anticlinorium at 

Booker T. Washington National Monument (Conley 

1978). 

Large deposits of sand, silt, and mud were deposited in 

near-shore deltaic, barrier island, and tidal flat 

environments along the eastern continental margin of 

the Iapetus basin (fig. 17C) (Schwab 1970; Kauffman and 

Frey 1979; Simpson 1991). As the Iapetus opened, 

spreading center volcanism (similar to the modern 

Atlantic spreading ridge) mixed basaltic lavas with 

marine sediments resulting in complex, heterogeneous 

stacks of rock. The erosionally resistant Cambrian 

Unicoi Formation (unit Cu, quartz pebble conglomerate; 

Chilhowee Group within the Blue Ridge thrust sheet)

was deposited in near-shore environments on attenuated 

continental crust (Henika 1997; Henika 2004). Rocks 
20 NPS Geologic Resources Division 

derived from volcanic processes in the Unicoi Formation 

indicate numerous volcanic centers active to the 

southeast of the Blue Ridge (Henika 2004). 

A large carbonate platform—similar to the Bahamas 

today—that existed during the Cambrian and Ordovician 

periods (545 to 480 million years ago) resulted in 

extensive deposits of carbonate rocks exposed in the 

Valley and Ridge province. The carbonate deposits 

thicken to the east (fig. 18D). Carbonate rocks deposited 

in passive margin sequences, foreland basins, intrashelf 

basins, and ramp to basin sequences form much of the 

Valley and Ridge Province in the Roanoke area of 

Virginia, west of the monument (Read 1983). Major 

formations include the Beekmantown Formation, 

Stonehenge Limestone, Conococheague Formation, 

Elbrook Formation, Waynesboro Formation, and Shady 

Dolomite (Henika 1997).

Paleozoic Era: Appalachian Mountain Building

Taconic Orogeny

Several orogenies are responsible for the Appalachian 

Mountains, deforming and metamorphosing sediments

and volcanics turning them into schists, gneisses, 

marbles, slates, and migmatites (Southworth et al. 2001). 

The repeated episodes resulted in a system of rocks 

characterized by northeast-striking thrust faults that are 

stacked vertically and shingled laterally. Many of the 

older thrust sheets (e.g. the Fries thrust sheet) have 

undergone multiple periods of deformation and have 

been crosscut in a variety of orientations by younger 

faulting (Pratt et al. 1988; Seaton and Burbey 2005). 

Many of these rocks are preserved in the greater Booker 

T. Washington National Monument area. Southeast of 

the Fries Fault, the thrust sheets of this part of the 

western Piedmont are increasingly deformed and have 

undergone metamorphism (Henika and Fokin 2006). 

From Early Cambrian through Early Ordovician time,

orogenic activity along the eastern margin of the North 

American continent was active. This included the closing 

of the Iapetus Ocean, subduction of oceanic crust, 

creation of volcanic arcs, and uplift of continental crust 

(fig. 18E) (Means 1995). The Taconic Orogeny (about

440 to 420 million years ago in the central Appalachians) 

was a convergence between a volcanic arc and the North 

American continent. Oceanic crust, basin sediments, and 

the volcanic arc that formed during subduction (within 

the Iapetus basin) were thrust onto the eastern edge of 

the North American continent (Sethi et al. 2000; Hibbard 

et al. 2001). Some geologists suggest that the fault 

separating the Ashe Metamorphic Suite (Ashe Formation 

of this report) from basement to the west (in North 

Carolina, south of Booker T. Washington National 

Monument) corresponds to a suture zone between the 

Piedmont and ancient continent of Laurentia (Stewart et 

al. 1999).

In response to the overriding plate thrusting westward 

onto the continental margin of North America, the crust 

bowed downward, creating a deep basin that filled with 

mud and sand eroded from the highlands to the east 

(Harris et al. 1997).

This Appalachian basin was centered on what is now 

West Virginia (fig. 18F). Sandstones, shales, siltstones, 

quartzites, and limestones were continuously deposited 

in fluvial deltaic to shallow marine environments of the 

Appalachian basin for a period of about 200 million years

during the Ordovician to the Permian periods. This 

deposition resulted in thick piles of sediments. The 

source of these sediments was from the highlands that 

were rising to the east during the Paleozoic orogenic 

events.

The Taconic Orogeny caused the initial metamorphism 

of the widespread Catoctin Formation, Alligator Back 

Formation, and other basalts into greenstones, 

metabasalts, and metarhyolites, as well as the basin 

sediments (graywackes) into quartzites, schists, gneisses,

and phyllites (Conley 1985; Trupe et al. 2004).

Deformation patterns occur throughout the region’s 

rocks on many scales ranging from broad, open regional

folds, to microscopic recrystallization textures. Fold 

patterns within the amphibolites of the Lynchburg 

Group delineate the primary structures of the Blue Ridge 

anticlinorium in the monument area (Conley 1985). 

Deformation during subsequent orogenic events created 

a series of overprinted folds in complex regional 

patterns. Later stage folds, such as the northeasttrending Cooper Creek anticline (located southeast of 

the monument), are evidence of further regional 

deformation (Conley 1985). 

The Piedmont Province contains large groupings of 

rocks that accreted onto North America during these 

intermittent collision events. Some were portions of 

island arcs or oceanic crust and others were fragments of 

other continents. These terranes typically form 

alternating, fault-bounded sequences of metamorphic 

rocks that have Late Paleozoic intrusions (Sacks 1999). 

East of Booker T. Washington National Monument, the 

Neoproterozoic to early Paleozoic Smith River 

allochthon is one example. The Sauratown Mountains 

anticlinorium is east of the Smith River allochthon 

(Conley 1978). Rocks within this body include the 

Cambrian Melrose Granite, Leatherwood Granite, 

Interlayered felsic and mafic metavolcanic and 

metasedimentary rocks, the Fork Mountain Formation 

(gneiss, schist, amphibolite, quartzite, and granofels), and 

the Bassett Formation (amphibolite, gneiss, and 

granofels) (Conley et al. 1981; Henika 1997). Rocks 

within this allochthon underwent a higher grade of 

metamorphism than the surrounding rocks (Sethi et al. 

2000). By contrast, rocks of the Lynchburg Formation 

are at greenschist grade and lower and locally contain 

some recognizable sedimentary structures (Conley and 

Henika 1973; Henika 2006).
BOWA Geologic Resources Inventory Report 21

Acadian Orogeny

The Acadian Orogeny (approximately 360 million years 

ago) continued the mountain building of the Taconic 

Orogeny, as the African continent approached North 

America, pushing ocean basin sediments and volcanic 

rocks westward (Harris et al. 1997). Similar to the 

preceding Taconic Orogeny, the Acadian Orogeny

involved land mass collision, mountain building, and 

regional metamorphism (Means 1995). This event was 

focused farther north than south-central Virginia. 

Piedmont metasediments record the Ordovician 

transition from passive margin sedimentation not 

associated with an orogeny to clastic sedimentation

associated with an orogeny. (Fisher 1976). East of Booker 

T. Washington National Monument, these 

metasediments include schists, metagraywackes, 

phyllites, gneiss, and metasiltstones. Oceanic crust 

caught up in the orogenic events now exists in the 

Piedmont Plateau as peridotites, metagabbros, 

serpentinite, and pyroxenites, among other 

metamorphosed mafic rocks (Drake et al. 1994; Mixon et 

al. 2000).

Alleghany Orogeny

The Iapetus Ocean was completely destroyed during the 

Late Paleozoic following the Acadian Orogeny, as the 

North American continent collided with the African 

continent during the formation of the supercontinent 

Pangaea. This mountain building episode, called the 

Alleghany Orogeny (about 325 to 265 million years ago)

formed the overall trend of the current Appalachian

mountain belt, and was the last major orogeny in the 

evolution of the Appalachian mountains (fig. 19G) 

(Means 1995). Deformation produced large Appalachian 

structures like the Sugarloaf Mountain anticlinorium and 

the Frederick Valley synclinorium in the western 

Piedmont and the Blue Ridge-South Mountain 

anticlinorium in the Valley and Ridge province

(Southworth et al. 2001). Deformation along the regional 

thrust faults near Booker T. Washington National 

Monument (Blue Ridge and Fries Faults) culminated 

during this event (Tracy et al. 1995; Nelson et al. 1999; 

Trupe et al. 2004).

During the Alleghany Orogeny, rocks of the Great Valley

(Shenandoah), Blue Ridge, and Piedmont provinces were 

transported, as a massive block (the Blue Ridge–

Piedmont thrust sheet), westward onto the younger 

rocks of the Valley and Ridge Province. Estimates of the 

horizontal shortening range from 20 to 50 percent which 

correlates to 125 to 350 km (75 to 125 mi) across the area 

(Harris et al. 1997). Shortening of just the Pulaski thrust 

sheet, one of a series of stacked thrust sheets west of 

Booker T. Washington National Monument is on the 

order of 80% with estimated westward displacements of 

approximately 100-110 km (62-68 mi) (Bartholomew 

1987). 

Metamorphism during the Alleghany Orogeny locally 

overprinted, but did not completely obliterate earlier 

metamorphic facies from the Taconic Orogeny (Nelson 

et al. 1999; Trupe et al. 2004). The thrust sheets of the 

western Piedmont were folded and faulted, and existing 

thrust faults were reactivated as both strike slip and 

thrust faults during the Alleghanian orogenic events 

(Southworth et al. 2001). Mylonites and migmatites,

indicating strong shearing, are characteristic of the 

terranes found in the thrust sheets of the Piedmont and 

Blue Ridge provinces (Simpson and Kalaghan 1987; 

Horton et al. 1999). These rocks form under intense heat 

and pressure during a deformation event. The Fries 

thrust zone contains mylonites with textures indicating 

right-lateral strike-slip motion in addition to thrust 

movement (Conley 1978; Simpson and Kalaghan 1987). 

Deformed plutons (i.e. the Striped Rock pluton) along 

the northwest edge of the Fries thrust sheet (to the 

southwest of the monument) indicate brittle deformation 

that both pre- and post-dates the primary phase of 

ductile deformation (Simpson and Kalaghan 1987).

Millions of years of erosion exposed the metamorphic

core of the Appalachian Mountains. Paleoelevations of 

the Alleghanian Appalachian Mountains are estimated at 

approximately 6,100 m (20,000 ft), analogous to the 

modern day Himalaya range in Asia.

Mesozoic Era: Rifting, Atlantic Ocean Formation, and 

Mountain Erosion

During the late Triassic, following the Alleghany

Orogeny, a period of rifting began from about 230 to 200 

million years ago (fig. 19H). The supercontinent Pangaea 

was pulled apart into roughly the continents that exist 

today. This episode of rifting initiated the formation of 

the current Atlantic Ocean, and caused many block-fault 

basins to develop with accompanying volcanism 

(Goodwin et al. 1986; Harris et al. 1997). Mesozoic riftblock basins in the monument area include the Danville, 

Farmville, and Taylorsville basins which are buried

beneath a thick cover of younger deposits (Conley 1985; 

Mixon et al. 2000).

The Triassic-age Newark Supergroup includes all of the 

Triassic-Jurassic sedimentary rocks deposited in a system 

of rift basins that trend roughly northeast-southwest 

exposed from Nova Scotia to South Carolina (Goodwin 

et al. 1986). Streams carried sediments from the recently 

uplifted Blue Ridge and Piedmont provinces depositing

large alluvial fans as they entered grabens. These deposits 

were lacustrine shales, siltstones, and sandstones. 

The large faults that formed the western boundaries of 

the basins created escarpments that were quickly 

covered with sediment. Igneous rocks, such as diabase,

intruded into the newly deposited sediments as sills and 

dikes that extend beyond the basins into adjacent rocks. 

Diabase in the west-central Virginia area tends to be rich 

in iron (Gottfried et al. 1991). Swarms of diabase dikes 

trend in north and northwesterly directions often with 

en echelon patterns (Conley 1985). Jurassic dikes and 

sills occur in the Booker T. Washington National 

Monument area (Henika 1997) and appear on the digital 

geologic map (unit Jd).

After these dikes and sills intruded during the Jurassic

the region underwent a period of slow uplift and erosion. 
22 NPS Geologic Resources Division 

The uplift was in response to isostatic adjustments within 

the crust, which pushed the continental crust upward 

and exposed it to further erosion (fig. 19I). Erosionally 

resistant diabase caps some of the higher ridges, hills, and 

slopes within each basin. Weathering of diabase tends to 

focus along joints and produce spheroidal boulders and 

ocherous (brown, yellow, or red) saprolite (Conley 

1985). These boulders may be a component of the field 

stones at Booker T. Washington National Monument. 

Following continental rifting, stream terrace gravels and 

deep residual soils developed on the gneissic rocks of the 

eastern Blue Ridge through nearly 200 million years of 

erosion (William S. Henika, geologist, Virginia 

Department of Natural Resources, written 

communication 2009). Recent dating near Martinsville, 

Virginia (Bank et al. 2001) indicates the weathered 

surface of the Piedmont, southeast of the Bowens CreekBrevard Fault, is 90-100 million years old whereas the 

surface developed across the fault on the eastern Blue 

Ridge is 149-197 million years old. Weathered surfaces 

throughout the area developed as southeastward flowing 

streams dissected the eastern flanks of the Blue Ridge 

uplift creating the eastern Atlantic margin (William S. 

Henika, geologist, Virginia Department of Natural 

Resources, written communication 2009). 

Throughout the Mesozoic Era, gravel, sand, and silt 

eroded from the mountains and were deposited at the 

base of the mountains as alluvial fans spreading eastward, 

covering metamorphic and igneous rocks and becoming

part of the Atlantic Coastal Plain (Duffy and Whittecar 

1991; Whittecar and Duffy 2000; Southworth et al. 2001).

The Roanoke River cuts the Cretaceous-age Potomac 

Formation, which is a widespread example of a clastic 

wedge deposited in this manner. The amount of material 

inferred for these deposits from exposed metamorphic 

equivalents of these sediments is immense. Many of the 

rocks exposed at the surface today were buried some

20 km (about 10 mi) below the surface prior to regional 

uplift and erosion. This burial is primarily due to 

continued deposition of sediment on the clastic wedge 

growing from the eroding mountains and crustal 

downwarping creating a dynamic accommodation space. 

The burial depth is inferred via geobarometry as 

indicated by the presence of certain combinations of 

metamorphic minerals.

Since the regional uplift of the Appalachian Mountains 

and the subsequent breakup of Pangaea, the North 

American plate has continued to drift toward the west, 

creating an eastern passive margin. Isostatic adjustments 

after the Alleghanian Orogeny continued at a subdued 

rate throughout the Cenozoic period (Harris et al. 1997).

These adjustments may be responsible for occasional 

seismic events felt throughout the region. Weathering 

and erosion continued throughout the Cenozoic era with 

early rivers cutting gaps through the mountains along 

zones of weakness such as faults. Rivers, like the 

Roanoke River and its tributaries (including Gills Creek),

continue to carve their channels, stripping the surficial 

deposits, lowering the mountains, and depositing alluvial 

terraces along the rivers, contributing to the present 

landscape (fig. 19J).

Cenozoic Era: Shaping the Modern Landscape

The geomorphology of the greater Booker T. 

Washington National Monument area was altered by

weathering, erosion and localized deposition over the 

past 5 million years. The erosion continues today along 

regional drainage patterns developed throughout the 

Cenozoic Era. Large rivers and tributaries such as Gills 

Creek and Jack-O-Lantern Branch are stripping 

sediments, lowering the mountains, and depositing 

alluvial terraces and alluvium and contributing to the 

present landscape. Rain, frost, rooted plants, rivers and 

streams, chemical dissolution, and mass wasting are all 

wearing away the once-craggy highlands. Layers of 

resistant rocks, such as quartzite and metaconglomerate

underlie local ridges and mountains. 

Although not included on the 1:100,000 scale digital 

geologic map (Appendix A), many surficial deposits of 

alluvium cover the landscape of Booker T. Washington 

National Monument. The position, distribution, 

thickness, and elevation of alluvium and low-lying 

alluvial terraces vary by province, age, and rock type. The 

elevations of terraces along the larger regional rivers 

show that the slope of the ancient and modern river 

valleys are similar, which suggests that the terraces 

formed as the result of either global sea level drop or 

regional uplift or both (Zen 1997a, 1997b).

From about 2.6 million years ago to 11,000 years ago, the

intermittent colder climates of the ice ages played a role 

in the formation of the landscape at Booker T. 

Washington National Monument. Continental glacial ice 

sheets of the Pleistocene Ice Ages never reached the 

south-central Virginia area (the southern terminus was in 

northeastern Pennsylvania). However, freeze and thaw 

cycles at higher elevations in the Blue Ridge led to 

increased erosion by ice wedging, freeze thaw and other 

cold weather mechanical weathering mechanisms. Many 

of the concentrations of boulders, block fields, and finetextured colluvium on the forested mountainsides of 

western Virginia record the process of frost-wedging. 

Sea level fluctuations during the Pleistocene caused the 

base level of many of the area’s rivers to change. During 

lowstands (sea level drops), the rivers would erode their 

channels, exposing the deformed bedrock of the 

Piedmont Plateau. During oceanic highstands, the river 

basins flooded and deposition resulted in beach 

sediments far west of current shorelines.
BOWA Geologic Resources Inventory Report 23

Figure 15: Geologic timescale. Included are major life history and tectonic events occurring on the North American continent. Red lines 

indicate major unconformities between eras. Isotopic ages shown are in millions of years (Ma). Compass directions in parentheses indicate 

the regional location of individual geologic events. Adapted from the U.S. Geological Survey, http://pubs.usgs.gov/fs/2007/3015/ with 

additional information from the International Commission on Stratigraphy. http://www.stratigraphy.org/view.php?id=25.
24 NPS Geologic Resources Division 

Figure 16: Geologic time scale specific to Virginia. Dates are approximate. Graphic is adapted from Bailey and Roberts 1997-2003.
BOWA Geologic Resources Inventory Report 25

Figure 17: Geologic evolution of the Appalachian Mountains in the Booker T. Washington National Monument area, west to east crosssectional view. A) First, intrusions of granite, metamorphism, and deformation related to the Grenville Orogeny lasted 60 million years, from 

1.1 billion to 950 million years ago; these rocks are found in the Blue Ridge province. B) Continental rifting and volcanic activity occurred in 

the Grenville terrane and turbidites were deposited in the deep water basin to the east; this activity continued for about 200 million years, 

from about 770 to 575 million years ago. C) The margin of the continent became stable with carbonate rocks deposited in quiet water (rocks 

of the current Great Valley). Shelly fossils appeared about 545 million years ago; then deep-water rocks were deposited into a basin east of 

the shelf margin for about 65 million years. Adapted from Southworth et al. (2001).
26 NPS Geologic Resources Division 

Figure 18: Geologic evolution of the Appalachian Mountains in the Booker T. Washington National Monument area, west to east crosssectional view. D and E) Following deposition, the stable shelf foundered as the Taconic Orogeny (480-460 million years ago) elevated the 

rocks to the east and provided a source for the clastic materials in Ordovician shales. Rocks in the Piedmont province were intruded by

plutonic rocks. F) Then, a thick sequence of sedimentary rocks were deposited in a deepening Appalachian basin for 120 million years. Most 

of these rocks are now found in the Valley and Ridge province. Adapted from Southworth et al. (2001).
BOWA Geologic Resources Inventory Report 27

Figure 19: Geologic evolution of the Appalachian Mountains in the Booker T. Washington National Monument area, west to east crosssectional view. G) About 240 million years ago, the continental plates of North America and Africa collided, resulting in the Alleghanian 

Orogeny. Many of the folds and faults in rocks west of the Piedmont province are related to this event. H) Continental rifting began and 

lasted for about 20 million years (220 to 200 million years ago). I) Thick sequences of sedimentary rock were deposited in fault-bounded 

basins while volcanic activity occurred. Rifting ultimately resulted in the creation of the Atlantic Ocean. The Culpeper and Farmville basins in 

the western Piedmont are the result of this event. J) For the past 200 million years, the landscape has eroded, and rivers have carried the 

sediment eastward to deposit the thick strata of the Atlantic Coastal Plain. The green star represents the approximate location of Booker T. 

Washington National Monument in the Blue Ridge. Diagrams are not to scale and are broadly representative of the tectonic settings. Adapted 

from Southworth et al. (2001).
28 NPS Geologic Resources Division 

Glossary

This glossary contains brief definitions of technical geologic terms used in this report. Not all 

geologic terms used are referenced. For more detailed definitions or to find terms not listed

here please visit: http://geomaps.wr.usgs.gov/parks/misc/glossarya.html. Definitions are 

based on those in the American Geological Institute Glossary of Geology (fifth edition; 2005).

active margin. A tectonically active margin where 

lithospheric plates come together (convergent 

boundary), pull apart (divergent boundary) or slide 

past one another (transform boundary). Typically 

associated with earthquakes and, in the case of 

convergent and divergent boundaries, volcanism. 

Compare to “passive margin.”

allochton. A mass of rock formed elsewhere and 

redeposited or transported to its present location.

allochthonous. Describes rocks or materials formed 

elsewhere and subsequently transported to their 

present location. Accreted terranes are one example.

alluvial fan. A fan-shaped deposit of sediment that 

accumulates where a hydraulically confined stream 

flows to a hydraulically unconfined area. Commonly 

out of a mountainous area into an area such as a valley 

or plain.

alluvium. Stream-deposited sediment.

amphibole. A common group of rock-forming silicate 

minerals. Hornblende is the most abundant type.

amphibolite. A metamorphic rock consisting mostly of 

the minerals amphibole and plagioclase with little or 

no quartz. 

anticline. A convex-upward (“A” shaped) fold. Older 

rocks are found in the center.

anticlinorium. A large, regional feature with an overall 

shape of an anticline. Composed of many smaller 

folds.

apatite. A group of variously colored phosphate 

minerals. Tooth enamel and bones contain minerals 

from the apatite group.

aquifer. A rock or sedimentary unit that is sufficiently 

porous that it has a capacity to hold water, sufficiently 

permeable to allow water to move through it, and 

currently saturated to some level.

arc. See “volcanic arc” and “magmatic arc.”

ash (volcanic). Fine material ejected from a volcano (also 

see “tuff”).

axis (fold). A straight line approximation of the trend of a 

fold which divides the two limbs of the fold. “Hinge 

line” is a preferred term.

base flow. Stream flow supported by groundwater; flow 

not attributed to direct runoff from precipitation or 

snow melt.

base level. The lowest level to which a stream can erode 

its channel. The ultimate base level for the land surface 

is sea level, but temporary base levels may exist locally. 

basement. The undifferentiated rocks, commonly 

igneous and metamorphic, that underlie rocks 

exposed at the surface.

basin (structural). A doubly plunging syncline in which 

rocks dip inward from all sides.

basin (sedimentary). Any depression, from continental to 

local scales, into which sediments are deposited.

bed. The smallest sedimentary strata unit, commonly 

ranging in thickness from one centimeter to a meter or 

two and distinguishable from beds above and below.

bedding. Depositional layering or stratification of 

sediments.

bedrock. A general term for the rock that underlies soil 

or other unconsolidated, surficial material.

block (fault). A crustal unit bounded by faults, either 

completely or in part.

breccia. A coarse-grained, generally unsorted, 

sedimentary rock consisting of cemented, angular

clasts larger than 2 mm (0.08 in)..

calcareous. Describes rock or sediment that contains the 

mineral calcium carbonate (CaCO3).

carbonaceous. Describes a rock or sediment with 

considerable carbon content, especially organics, 

hydrocarbons, or coal.

carbonate. A mineral that has CO3

-2 as its essential 

component (e.g., calcite and aragonite).

carbonate rock. A rock consisting chiefly of carbonate 

minerals (e.g., limestone, dolomite, or carbonatite).

cementation. Chemical precipitation of material into 

pores between grains that bind the grains into rock.

chemical sediment. A sediment precipitated directly from 

solution (also called nonclastic).

chemical weathering. Chemical breakdown of minerals 

at Earth’s surface via reaction with water, air, or 

dissolved substances; commonly results in a change in 

chemical composition more stable in the current 

environment.

clast. An individual grain or rock fragment in a 

sedimentary rock, produced by the physical 

disintegration of a larger rock mass.

clastic. Describes rock or sediment made of fragments of 

pre-existing rocks (clasts).

clay. Can be used to refer to clay minerals or as a 

sedimentary fragment size classification (less than 

1/256 mm [0.00015 in]).

claystone. Lithified clay having the texture and 

composition of shale but lacking shale’s fine layering 

and fissility (characteristic splitting into thin layers).

cleavage (mineral). The tendency of a mineral to break 

preferentially in certain directions along planes of 

weaknesses in the crystal structure.

cleavage. The tendency of a rock to split along parallel,

closely spaced planar surfaces. It is independent of 

bedding.

colluvium. A general term applied to any loose, 

heterogeneous, and incoherent mass of rock fragments 

deposited by unconcentrated surface runoff or slow 
BOWA Geologic Resources Inventory Report 29

continuous downslope creep, usually collecting at the 

base of gentle slopes or hillsides.

concordant. Strata with contacts parallel to the 

orientation of adjacent strata.

conglomerate. A coarse-grained, generally unsorted, 

sedimentary rock consisting of cemented, rounded 

clasts larger than 2 mm (0.08 in).

continental crust. Crustal rocks rich in silica and alumina 

that underlie the continents; ranging in thickness from 

35 km (22 mi) to 60 km (37 mi) under mountain ranges.

continental shield. A continental block of Earth’s crust 

that has remained relatively stable over a long period 

of time and has undergone minor warping compared 

to the intense deformation of bordering crust.

convergent boundary. A plate boundary where two 

tectonic plates are colliding.

craton. The relatively old and geologically stable interior 

of a continent (also see “continental shield”).

creep. The slow, imperceptible downslope movement of 

mineral, rock, and soil particles under gravity.

cross-bedding. Uniform to highly varied sets of inclined 

sedimentary beds deposited by wind or water that 

indicate flow conditions such as water flow direction 

and depth.

cross section. A graphical interpretation of geology, 

structure, and/or stratigraphy in the third (vertical) 

dimension based on mapped and measured geological 

extents and attitudes depicted in a vertically oriented 

plane.

crust. Earth’s outermost compositional shell, 10 to 40 km 

(6 to 25 mi) thick, consisting predominantly of 

relatively low-density silicate minerals (also see 

“oceanic crust” and “continental crust”).

crystalline. Describes a regular, orderly, repeating 

geometric structural arrangement of atoms.

crystal structure. The orderly and repeated arrangement 

of atoms in a crystal.

debris flow. A moving mass of rock fragments, soil, and 

mud, in which more than half the particles of which 

are larger than sand size. 

deformation. A general term for the processes of faulting, 

folding, and shearing of rocks as a result of various 

Earth forces such as compression (pushing together) 

and extension (pulling apart).

delta. A sediment wedge deposited where a stream flows 

into a lake or sea.

dike. A narrow igneous intrusion that cuts across 

bedding planes or other geologic structures.

dip. The angle between a bed or other geologic surface 

and horizontal.

dip-slip fault. A fault with measurable offset where the 

relative movement is parallel to the dip of the fault.

discordant. Describes contacts between strata that cut 

across or are set at an angle to the orientation of 

adjacent rocks.

divergent boundary. An active boundary where tectonic 

plates are moving apart (e.g., a spreading ridge or 

continental rift zone).

drainage basin. The total area from which a stream 

system receives or drains precipitation runoff.

ductile. Describes a rock that is able to sustain 

deformation (folding, bending, or shearing) before 

fracturing.

ephemeral stream. A stream that flows briefly only in 

direct response to precipitation in the immediate 

locality and whose channel is at all times above the 

water table. 

epicenter. The point on Earth’s surface that is directly 

above the focus (location) of an earthquake.

eustatic. Relates to simultaneous worldwide rise or fall of 

sea level.

extrusive. Describes molten (igneous) material that has 

erupted onto Earth’s surface.

facies (metamorphic). The pressure and temperature 

conditions that result in a particular, distinctive suite 

of metamorphic minerals.

facies (sedimentary). The depositional or environmental 

conditions reflected in the sedimentary structures, 

textures, mineralogy, fossils, etc. of a sedimentary 

rock.

fault. A break in rock along which relative movement has 

occurred between the two sides.

felsic. Describes an igneous rock having abundant lightcolored minerals such as quartz, feldspars, or 

muscovite. Compare to “mafic.”

fold. A curve or bend of an originally flat or planar 

structure such as rock strata, bedding planes, or 

foliation that is usually a product of deformation.

foliation. A preferred arrangement of crystal planes in 

minerals. In metamorphic rocks, the term commonly 

refers to a parallel orientation of planar minerals such 

as micas.

footwall. The mass of rock beneath a fault surface (also 

see “hanging wall”).

formation. Fundamental rock-stratigraphic unit that is 

mappable, lithologically distinct from adjoining strata, 

and has definable upper and lower contacts.

fracture. Irregular breakage of a mineral; also any break 

in a rock (e.g., crack, joint, or fault).

frost wedging. The breakup of rock due to the 

expansion of water freezing in fractures.

geology. The study of Earth including its origin, history, 

physical processes, components, and morphology.

graben. A down-dropped structural block bounded by 

steeply dipping, normal faults (also see “horst”).

granoblastic. Describes the texture of a metamorphic 

rock in which recrystallization formed crystals of 

nearly the same size in all directions.

granodiorite. A group of intrusive igneous (plutonic)

rocks containing quartz, plagioclase, and potassium 

feldspar minerals with biotite, hornblende, or, more 

rarely, pyroxene, as the mafic components.

graywacke. A term commonly used in the field for a dark 

gray to dark green, very hard, dense sandstone of any 

composition but with a chlorite-rich matrix; these 

rocks have undergone deep burial.

greenschist. A metamorphic rock, whose green color is 

due to the presence of the minerals chlorite, epidote, 

or actinolite, corresponds with metamorphism at 

temperatures in the 300–500°C (570–930°F) range. 

hanging wall. The mass of rock above a fault surface 

(also see “footwall”).

hinge line. A line or boundary between a stable region 

and one undergoing upward or downward movement.

hoodoo. A pillar of rock developed by erosion of 

horizontal strata of varying hardness. Typically found 
30 NPS Geologic Resources Division 

in climatic zones where most rainfall is concentrated 

during a short period of the year.

hornblende. The most common mineral of the 

amphibole group. Hornblende is commonly black and 

occurs in distinct crystals or in columnar, fibrous, or 

granular forms.

horst. Areas of relative “up” between grabens, 

representing the geologic surface left behind as 

grabens drop. The best example is the Basin-andRange province of Nevada. The basins are grabens and 

the ranges are weathered horsts. Grabens become a 

locus for sedimentary deposition (also see “graben”).

igneous. Refers to a rock or mineral that originated from 

molten material; one of the three main classes of 

rocks—igneous, metamorphic, and sedimentary.

intrusion. A body of igneous rock that invades (pushes 

into) older rock. The invading rock may be a plastic 

solid or magma.

island arc. A line or arc of volcanic islands formed over 

and parallel to a subduction zone.

isostacy. The condition of equilibrium, comparable to 

floating, of the units of the lithosphere above the 

asthenosphere. Crustal loading (commonly by large ice 

sheets) leads to isostatic depression or downwarping; 

removal of the load leads to isostatic uplift or 

upwarping.

joint. A break in rock without relative movement of 

rocks on either side of the fracture surface.

karst topography. Topography characterized by 

abundant sinkholes and caverns formed by the 

dissolution of calcareous rocks.

lacustrine. Pertaining to, produced by, or inhabiting a 

lake or lakes.

lamination. Very thin, parallel layers.

landslide. Any process or landform resulting from rapid, 

gravity-driven mass movement.

lapilli. Pyroclastics in the general size range of 2 to 64 mm 

(0.08 to 2.5 in.).

lava. Still-molten or solidified magma that has been 

extruded onto Earth’s surface though a volcano or 

fissure.

limb. Either side of a structural fold.

limestone. A sedimentary rock consisting chiefly of 

calcium carbonate, primarily in the form of the mineral 

calcite.

lineament. Any relatively straight surface feature that can 

be identified via observation, mapping, or remote 

sensing, often reflects crustal structure.

lithic. A sedimentary rock or pyroclastic deposit that 

contains abundant fragments of previously formed 

rocks.

lithification. The conversion of sediment into solid rock.

lithify. To change to stone or to petrify; especially to 

consolidate from a loose sediment to a solid rock 

through compaction and cementation. 

lithology. The physical description or classification of a 

rock or rock unit based on characters such as its color, 

mineral composition, and grain size.

mafic. Describes dark-colored rock, magma, or minerals 

rich in magnesium and iron. Compare to “felsic.”

magma. Molten rock beneath Earth’s surface capable of 

intrusion and extrusion. 

mantle. The zone of Earth’s interior between the crust 

and core.

mass wasting. A general term for the downslope 

movement of soil and rock material under the direct 

influence of gravity.

matrix. The fine grained material between coarse (larger) 

grains in igneous rocks or poorly sorted clastic 

sediments or rocks. Also refers to rock or sediment in 

which a fossil is embedded.

meander. Sinuous lateral curve or bend in a stream 

channel. An entrenched meander is incised, or carved 

downward into the surface of the valley in which a 

meander originally formed. The meander preserves its 

original pattern with little modification.

mechanical weathering. The physical breakup of rocks 

without change in composition. Synonymous with 

“physical weathering.”

member. A lithostratigraphic unit with definable 

contacts; a member subdivides a formation.

meta–. A prefix used with the name of a sedimentary or 

igneous rock, indicating that the rock has been 

metamorphosed.

metamorphic. Describes the process of metamorphism 

or its results. One of the three main classes of rocks—

igneous, metamorphic, and sedimentary.

metamorphism. Literally, a change in form. 

Metamorphism occurs in rocks through mineral 

alteration, formation, and/or recrystallization from 

increased heat and/or pressure.

migmatite. Literally, “mixed rock” with both igneous 

and metamorphic characteristics due to partial melting 

during metamorphism.

mineral. A naturally occurring, inorganic crystalline solid 

with a definite chemical composition or compositional 

range.

mylonite. A fine-grained, foliated rock typically found in 

localized zones of ductile deformation, often formed at 

great depths under high temperature and pressure.

normal fault. A dip-slip fault in which the hanging wall 

moves down relative to the footwall.

obduction. The process by which the crust is thickened 

by thrust faulting at a convergent margin.

oceanic crust. Earth’s crust formed at spreading ridges 

that underlies the ocean basins. Oceanic crust is 6 to 7 

km (3 to 4 miles) thick and generally of basaltic 

composition.

ophiolite. An assemblage of ultramafic and mafic 

intrusive and extrusive igneous rock, probably 

representing oceanic crust.

orogeny. A mountain-building event.

outcrop. Any part of a rock mass or formation that is 

exposed or “crops out” at Earth’s surface.

overbank deposit. Alluvium deposited outside a stream 

channel during flooding.

overburden. Rock and sediment, not of economic value, 

and often unconsolidated, that overlies an ore, fuel, or 

sedimentary deposit.

paleontology. The study of the life and chronology of 

Earth’s geologic past based on the fossil record.

Pangaea. A theoretical, single supercontinent that 

existed during the Permian and Triassic periods.

parabolic dune. Crescent-shaped dune with horns or 

arms that point upwind.
BOWA Geologic Resources Inventory Report 31

parent material. Geologic material from which soils 

form.

parent rock. Rock from which soil, sediments, or other 

rocks are derived.

passive margin. A margin where no plate-scale tectonism 

is taking place; plates are not converging, diverging, or 

sliding past one another. An example is the east coast 

of North America (compare to “active margin”).

permeability. A measure of the relative ease with which 

fluids move through the pore spaces of rocks or 

sediments.

phenocryst. A coarse (large) crystal in a porphyritic

igneous rock.

phyllite. A metamorphosed rock, intermediate in grade 

between slate and mica schist, with minute crystals of 

graphite, sericite, or chlorite that impart a silky sheen 

to the surfaces (“schistosity”).

plastic. Capable of being deformed permanently without 

rupture.

plate tectonics. The concept that the lithosphere is 

broken up into a series of rigid plates that move over 

Earth’s surface above a more fluid asthenosphere.

plateau. A broad, flat-topped topographic high 

(terrestrial or marine) of great extent and elevation 

above the surrounding plains, canyons, or valleys.

pluton (plutonic). A body of intrusive igneous rock that 

crystallized at some depth beneath Earth’s surface.

podzolic soil. soil usually forming in a broadleaf forest 

and characterized by moderate leaching, which 

produces an accumulation of clay and, to some degree, 

iron that have been transported (eluviated) from 

another area by water.

point bar. A low ridge of sand and gravel deposited in a 

stream channel on the inside of a meander where flow 

velocity slows.

porosity. The proportion of void space (e.g., pores or 

voids) in a volume of rock or sediment deposit.

porphyry. An igneous rock consisting of abundant coarse 

crystals in a fine-grained matrix.

protolith. The parent or unweathered and/or 

unmetamorphosed rock from which regolith or 

metamorphosed rock is formed. 

provenance. A place of origin. The area from which the 

constituent materials of a sedimentary rock were 

derived.

recharge. Infiltration processes that replenish 

groundwater.

regolith. General term for the layer of rock debris, 

organic matter, and soil that commonly forms the land 

surface and overlies most bedrock.

regression. A long-term seaward retreat of the shoreline 

or relative fall of sea level.

relative dating. Determining the chronological 

placement of rocks, events, or fossils with respect to 

the geologic time scale and without reference to their 

numerical age.

reverse fault. A contractional high-angle (greater than 

45°

) dip-slip fault in which the hanging wall moves up 

relative to the footwall (also see “thrust fault”).

rift. A region of crust where extension results in 

formation of many related normal faults, often 

associated with volcanic activity.

rift valley. A depression formed by grabens along the 

crest of an oceanic spreading ridge or in a continental 

rift zone.

rilles. A trench-like or crack-like valley, commonly 

occurring on planetary surfaces subjected to plains 

volcanism; they may be irregular with meandering 

courses (sinuous rilles) or relatively straight (normal 

rilles).

rock. A solid, cohesive aggregate of one or more minerals.

rock fall. Mass wasting process where rocks are 

dislodged and move downslope rapidly; it is the fastest 

mass wasting process.

roundness. The relative amount of curvature of the 

“corners” of a sediment grain.

saprolite. A soft, earthy, typically clay-rich, thoroughly 

decomposed rock, formed in place by chemical 

weathering of igneous, sedimentary, and metamorphic 

rocks.

sand. A clastic particle smaller than a granule and larger 

than a silt grain, having a diameter in the range of 1/16 

mm (0.0025 in) to 2 mm (0.08 in).

sandstone. Clastic sedimentary rock of predominantly 

sand-sized grains.

scarp. A steep cliff or topographic step resulting from 

displacement on a fault, or by mass movement, or 

erosion. Also called an “escarpment.”

schist. A strongly foliated metamorphic rock that can be 

readily be split into thick flakes or slabs. Micas are 

arranged in parallel, imparting a distinctive sheen, or 

“schistosity” to the rock.

schistose. A rock displaying schistosity, or foliation.

seafloor spreading. The process by which tectonic plates 

pull apart and new lithosphere is created at oceanic 

ridges.

sediment. An eroded and deposited, unconsolidated 

accumulation of rock and mineral fragments.

sedimentary rock. A consolidated and lithified rock 

consisting of clastic and/or chemical sediment(s). One 

of the three main classes of rocks—igneous, 

metamorphic, and sedimentary.

sequence. A major informal rock-stratigraphic unit that 

is traceable over large areas and defined by a 

sediments associated with a major sea level 

transgression-regression.

shale. A clastic sedimentary rock made of clay-sized 

particles that exhibit parallel splitting properties.

silicate. A compound whose crystal structure contains 

the SiO4 tetrahedra.

silt. Clastic sedimentary material intermediate in size 

between fine-grained sand and coarse clay (1/256 to 

1/16 mm [0.00015 to 0.002 in]).

siltstone. A variably lithified sedimentary rock composed 

of silt-sized grains.

slope. The inclined surface of any geomorphic feature or 

measurement thereof. Synonymous with “gradient.”

slump. A generally large, coherent mass movement with a 

concave-up failure surface and subsequent backward 

rotation relative to the slope.

soil. Surface accumulation of weathered rock and 

organic matter capable of supporting plant growth and 

often overlying the parent material from which it 

formed.
32 NPS Geologic Resources Division 

spring. A site where water issues from the surface due to 

the intersection of the water table with the ground 

surface.

strata. Tabular or sheet-like masses or distinct layers of 

rock.

stratification. The accumulation, or layering of 

sedimentary rocks in strata. Tabular, or planar, 

stratification refers to essentially parallel surfaces. 

Cross-stratification refers to strata inclined at an angle 

to the main stratification.

stratigraphy. The geologic study of the origin, 

occurrence, distribution, classification, correlation, 

and age of rock layers, especially sedimentary rocks.

stream. Any body of water moving under gravity flow in 

a clearly confined channel.

stream channel. A long, narrow depression shaped by the 

concentrated flow of a stream and covered 

continuously or periodically by water.

stream terrace. Step-like benches surrounding the 

present floodplain of a stream due to dissection of 

previous flood plain(s), stream bed(s), and/or valley 

floor(s).

strike. The compass direction of the line of intersection 

of an inclined surface with a horizontal plane.

strike-slip fault. A fault with measurable offset where the 

relative movement is parallel to the strike of the fault. 

Said to be “sinistral” (left-lateral) if relative motion of 

the block opposite the observer appears to be to the 

left. “Dextral” (right-lateral) describes relative motion 

to the right.

structural geology. The branch of geology that deals with 

the description, representation, and analysis of 

structures, chiefly on a moderate to small scale. The 

subject is similar to tectonics, but the latter is generally 

used for the broader regional or historical phases.

structure. The attitude and relative positions of the rock 

masses of an area resulting from such processes as 

faulting, folding, and igneous intrusions.

subduction zone. A convergent plate boundary where 

oceanic lithosphere descends beneath a continental or 

oceanic plate and is carried down into the mantle.

subsidence. The gradual sinking or depression of part of 

Earth’s surface.

suture. The linear zone where two continental 

landmasses become joined via obduction.

syncline. A downward curving (concave up) fold with 

layers that dip inward; the core of the syncline 

contains the stratigraphically-younger rocks.

synclinorium. A composite synclinal structure of regional 

extent composed of lesser folds.

system (stratigraphy). The group of rocks formed during 

a period of geologic time.

tectonic. Relating to large-scale movement and 

deformation of Earth’s crust.

terrace. A relatively level bench or steplike surface 

breaking the continuity of a slope (also see “stream 

terrace”).

terrane. A large region or group of rocks with similar 

geology, age, or structural style.

thrust fault. A contractional dip-slip fault with a 

shallowly dipping fault surface (less than 45°) where 

the hanging wall moves up and over relative to the 

footwall.

topography. The general morphology of Earth’s surface, 

including relief and locations of natural and 

anthropogenic features.

trace (fault). The exposed intersection of a fault with 

Earth’s surface.

transgression. Landward migration of the sea as a result 

of a relative rise in sea level.

trend. The direction or azimuth of elongation of a linear 

geologic feature.

tuff. Generally fine-grained, igneous rock formed of 

consolidated volcanic ash.

type locality. The geographic location where a 

stratigraphic unit (or fossil) is well displayed, formally 

defined, and derives its name. The place of original 

description.

ultramafic. Describes rock composed chiefly of mafic 

(dark-colored, iron and magnesium rich) minerals.

unconformity. An erosional or non-depositional surface 

bounded on one or both sides by sedimentary strata.

An unconformity marks a period of missing time.

undercutting. The removal of material at the base of a 

steep slope or cliff or other exposed rock by the 

erosive action of falling or running water (such as a 

meandering stream), of sand-laden wind in the desert, 

or of waves along the coast.

uplift. A structurally high area in the crust, produced by 

movement that raises the rocks.

vent. An opening at Earth’s surface where volcanic 

materials emerge.

volcanic. Describes anything related to volcanoes. Can 

refer to igneous rock crystallized at or near Earth’s 

surface (e.g., lava).

volcanic arc. A commonly curved, linear, zone of 

volcanoes above a subduction zone. 

water table. The upper surface of the saturated zone; the 

zone of rock in an aquifer saturated with water.

weathering. The physical, chemical, and biological 

processes by which rock is broken down.
BOWA Geologic Resources Inventory Report 33

Literature Cited

This section lists references cited in this report. A more complete geologic bibliography is 

available from the National Park Service Geologic Resources Division.

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development in the Roanoke-Salem area, Virginia. 

Geological Society of America Abstracts with 

Programs 5 (5):374.

Bank, G. C., J. A. Spotila, and P. W. Reiners. 2001. Origin 

of an eastern North America Great Escarpment based 

on (U-Th)/He dating and geomorphic analysis. Eos 

Transactions, American Geophysical Union 82 (19 fall 

meeting supplement):T52C–0957.

Bartholomew, M. J. 1981. Geology of the Roanoke and 

Stewartsville quadrangles, Virginia (scale 1:24,000). 

Publication 34. Virginia Division of Mineral 

Resources, Charlottesville, VA, USA.

Bailey, C. M. 1999. Generalized Geologic Terrane Map 

of the Virginia Piedmont and Blue Ridge. College of 

William and Mary. (http://www.wm.edu/geology/ 

virginia/terranes.html). Accessed 6 June 2005.

Bartholomew, M. J. 1987. Structural evolution of the 

Pulaski thrust system, southwestern Virginia. 

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Bartholomew, M. J., and S. E. Lewis. 1977. Relationships 

of the Fries Thrust to the basement complex and 

Paleozoic deformation in the Blue Ridge of 

northwestern North Carolina and southwestern 

Virginia. Geological Society of America Abstracts with 

Programs 9 (2):116–117.

Conley, J. F. 1978. Geology of the Piedmont of Virginia–

interpretation and problems. Pages 115–149 in

Contributions to Virginia Geology III, Publication 7.

Virginia Division of Mineral Resources,

Charlottesville, VA, USA.

Conley, J. F. 1985. Geology of the southwestern Virginia 

Piedmont (scale 1:125,000). Publication 59. Virginia 

Division of Mineral Resources, Charlottesville, VA, 

USA.

Conley, J. F., and W. S. Henika. 1973. Field trip across 

the Blue Ridge anticlinorium, Smith River allochthon, 

and Sauratown Mountains anticlinorium near 

Martinsville, Virginia. Virginia Minerals 19 (4):37–44.

Conley, J. F., J. D. Marr Jr., and C. R. Berquist Jr. 1981. 

Stratigraphic relationships between rocks of the Blue 

Ridge anticlinorium and the Smith River allochthon in 

the southwestern Virginia Piedmont. Annual Virginia 

Geology Field Conference 13. Virginia Division of 

Mineral Resources, Charlottesville, VA, USA.

Dalziel, I. W. D. 1995. Earth before Pangea: the North 

American continent may be more nomadic than an of 

its inhabitants. Scientific American 272 (1):60.

De Vore, S. D. 1998. Geophysical investigations of the 

three areas within the boundaries of Booker T. 

Washington National Monument, Franklin County, 

VA. Intermountain Region Archaeological Project 

Report. Booker T. Washington National Monument, 

Hardy, VA. National Park Service, Washington, DC, 

USA.

Dietrich, R. V. 1990. Geology and Virginia. Virginia 

Division of Mineral Resources, Charlottesville, VA, 

USA.

Drake, A. A., Jr., A. J. Froelich, R. E. Weems, and K. Y. 

Lee. 1994. Geologic map of the Manassas Quadrangle, 

Fairfax and Prince William counties, Virginia (scale 

1:24,000). Geologic Quadrangle Map GQ-1732. U.S. 

Geological Survey, Washington, D.C., USA.

Duffy, D. F. and G. R. Whittecar. 1991. Geomorphic 

development of segmented alluvial fans in the 

Shenandoah Valley, Stuarts Draft, Virginia. Geological 

Society of America Abstracts with Programs 23 (1):24. 

Fisher, G. W. 1976. The geologic evolution of the 

northeastern Piedmont of the Appalachians. 

Geological Society of America Abstracts with 

Programs 8 (2):172–173. 

Gilliam, D. R., and W. S. Henika. 1999. Geology and 

engineering challenges of southwest Virginia. 

Proceedings of the Annual Highway Geology 

Symposium 50:365–387.

Goodwin, B. K., K. W. Ramsey, and G. P. Wilkes. 1986. 

Guidebook to the geology of the Richmond, Farmville, 

Briery Creek and Roanoke Creek basins, Virginia. 

Annual Virginia Geology Field Conference 18.

Gottfried, D., A. J. Froelich, and J. N. Grossman. 1991. 

Geochemical data for Jurassic diabase associated with 

early Mesozoic basins in the Eastern United States: 

Farmville and Scottsville basins and vicinity, Virginia

(scale 1:125,000). Open-File Report 91-0322. U.S. 

Geological Survey, Washington, D.C., USA.

Harris, A. G., E. Tuttle, and S. D. Tuttle. 1997. Geology of 

National Parks. Kendall/Hunt Publishing Company, 

Dubuque, IA, USA.

Hendrick, S. 1978. This is Your Soil and Water 

Conservation Plan. Booker T. Washington National 
34 NPS Geologic Resources Division 

Monument. Blue Ridge Soil and Water Conservation 

District, Virginia. 

Henika, W. S. 1992. Stratigraphy of the eastern Blue 

Ridge sequence in the Roanoke 30' X 60' Quadrangle, 

Virginia. Geological Society of America Abstracts with 

Programs 24 (2):21.

Henika, W. S. 1997. Geologic map of the Roanoke 30 X 

60 minute quadrangle (scale 1:100,000). Map 148. 

Virginia Division of Mineral Resources, 

Charlottesville, VA, USA.

Henika, W. S. 2004. Unicoi lavas in the Blue Ridge of SW 

Virginia. Geological Society of America Abstracts with 

Programs 36 (2):88.

Henika, W. S., and M. Fokin. 2006. Petrology and 

geochemistry of metamorphosed Proterozoic igneous 

rocks in the Blue Ridge and western Piedmont terranes 

near Roanoke, Virginia. Geological Society of America 

Abstracts with Programs 38 (3):9.

Henika, W. S., J. Beard, R. Tracy, and J. R. Wilson. 2000. 

Structure and Tectonics Field Trip to Eastern Blue 

Ridge and Western Piedmont near Martinsville, 

Virginia. (Modified from Virginia minerals 46(3): 17-

32). 

(http://www.geology.state.va.us/Pub/VAMINS/v46no

3/vamin463.htm). Accessed 29 August 2009.

Hibbard, J., K. G. Stewart, and W. S. Henika. 2001. 

Framing the Piedmont zone in North Carolina and 

Virginia. Pages 1–26 in Hoffman, C. W., editor. Field 

Trip Guidebook for the 50th annual meeting of the 

Southeastern Section of the Geological Society of 

America, Geological Society of America, Raleigh, NC, 

USA. 

Horton, J. W., Jr., and V. A. Zullo. 1991. An introduction 

to the geology of the Carolinas. Pages 1–10 in J. W., 

Horton ,Jr., and V. A. Zullo, editors. The geology of 

the Carolinas: Carolina Geological Society fiftieth 

anniversary volume. University of Tennessee Press, 

Knoxville, TN, USA.

Horton, J. W., Jr., J. N. Aleinikoff, W. C. Burton, J. D. 

Peper, and P. C. Hackley. 1999. Geologic framework of 

the Carolina slate belt in southern Virginia: insights 

from geologic mapping and U-Pb geochronology. 

Geological Society of America Abstracts with 

Programs 31 (7):476. 

Hunt, C. B. 1972. Geology of Soils; their evolution, 

classification, and uses. W. H. Freeman Co., San 

Francisco, CA, USA. 

Karl, T. R., J. M. Melillo, and T. C. Peterson, editors. 

2009. Global climate change impacts in the United 

States. Cambridge University Press, New York, NY, 

USA. http://www.globalchange.gov/publications/

reports/scientific-assessments/us-impacts Accessed 23 

August 2010.

Kauffman, M. E, and E. P. Frey. 1979. Antietam 

sandstone ridges: exhumed barrier islands or faultbounded blocks? Geological Society of America 

Abstracts with Programs 11 (1):18.

Legrand, H. E. 1960. Geology and ground-water 

resources of Pittsylvania and Halifax counties, 

Virginia. Publication 75. Virginia Division of Mineral 

Resources, Charlottesville, VA, USA.

Means, J. 1995. Maryland's Catoctin Mountain parks: an 

interpretive guide to Catoctin Mountain Park and 

Cunningham Falls State Park. McDonald & 

Woodward Publishing, Blacksburg, VA, USA. 

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R. E. Weems, J. S. Schindler, W. L. Newell, L E. 

Edwards, and L. W. Ward. 2000. Geologic Map of the 

Fredericksburg 30’x60’ Quadrangle, Virginia and 

Maryland (scale 1:100,000). Geologic Investigations 

Series Map I-2607. U.S. Geological Survey, 

Washington, D.C., USA.

Nance, R. D. and U. Linnemann. 2008. The Rheic Ocean; 

origin, evolution, and significance. GSA Today 18 

(12):4–12. 

National Park Service. 1997. Baseline water quality data 

inventory and analysis: Booker T. Washington 

National Monument. Technical Report 

NPS/NRWRD/NRTR-97/116. Water Resources 

Division, Fort Collins, CO, USA. 

(http://www.nature.nps.gov/water/horizon.cfm). 

Accessed 26 August 2010.

National Park Service. 2007. Soil Survey Geographic 

(SSURGO) database for Booker T. Washington 

National Monument, Virginia. Geologic Resources 

Division, Soil Resources Inventory Program, 

Lakewood, CO, USA. http://science.nature.nps.gov/

nrdata/datastore.cfm?ID=48824. Accessed 26 August 

2010.

Nelson, A. E., J. D. Marr, Jr., and K. E. Olinger. 1999. 

Reconnaissance bedrock geologic map of the Red 

House, Madisonville, Aspen, and Charlotte Court 

House 7.5-minute quadrangles, Charlotte, Prince 

Edward, Appomattox, Campbell, and Halifax counties, 

Virginia (scale 1:48,000). Open-File Report 99-0538. 

U.S. Geological Survey, Washington, D.C., USA.

O’Hara, K. 1990. State of strain in mylonites from the 

western Blue Ridge Province, Southern Appalachians; 

the role of volume loss. Journal of Structural Geology 

12 (4):419–430.

Pratt, T. L., C. Çoruh, J. K. Costain, and L. Glover III. 

1988. A geophysical study of the Earth’s crust in 

central Virginia; Implications for Appalachian crustal 

structure. Journal of Geophysical Research 93 

(B6):6649–6667.

Read, J. F. 1983. Field trip guide to lower Paleozoic 

carbonate rocks, Roanoke region, Virginia. Virginia 
BOWA Geologic Resources Inventory Report 35

Polytechnic Institute and State University, Blacksburg, 

VA, USA.

Schwab, F. L. 1970. Origin of the Antietam Formation 

(late Precambrian?; lower Cambrian), central Virginia 

Journal of Sedimentary Petrology 40 (1):354–366.

Seaton, W. J., and T. J. Burbey. 2005. Influence of ancient 

thrust faults on the hydrogeology of the Blue Ridge

Province. Ground Water 43 (3):301–313.

Sethi, P. S., R. C. Whisonant, K. K Cecil, and P. L. 

Newbill. 2000. Geology of Virginia: Piedmont and Blue 

Ridge. (CD-ROM #3). 2 CD-ROMs. Virginia Division 

of Mineral Resources, Charlottesville, VA, USA

Simpson, E. L. 1991. An exhumed Lower Cambrian tidalflat: the Antietam Formation, central Virginia, U.S.A, 

In Clastic tidal sedimentology, eds. D. G. Smith, B. A. 

Zaitlin, G. E. Reinson, and R. A. Rahmani. Memoir -

Canadian Society of Petroleum Geologists 16:123–133.

Simpson, C., and T. Kalaghan. 1987. Deformation in the 

Striped Rock Pluton, NW margin of the Fries thrust 

zone, SW Virginia. Geological Society of America 

Abstracts with Programs 19 (2):129.

Southworth, S., D. K. Brezinski, R. C. Orndorff, P. G. 

Chirico, and K. M. Lagueux. 2001. Geology of the 

Chesapeake and Ohio Canal National Historical Park 

and Potomac River Corridor, District of Columbia, 

Maryland, West Virginia, and Virginia; A, Geologic 

map and GIS files (disc 1); B, Geologic report and

figures (disc 2). Open-File Report 01-0188. U.S. 

Geological Survey, Washington, D.C., USA.

Stewart, K. G., M. G. Adams, C. H. Trupe, L. K. Hewitt, 

and C. L. Waters. 1999. Paleozoic structural and 

metamorphic history of the eclogite-bearing Fries 

thrust sheet and adjacent thrust sheets of the Blue 

Ridge thrust complex, North Carolina. Geological 

Society of America Abstracts with Programs 31 (3):69.

Tracy, R. J., E. Holmstad, and E. W. Weissbart. 1995. 

Deformed and undeformed Proterozoic charnockites 

of the Blue Ridge, southwestern Virginia. Eos, 

Transactions, American Geophysical Union 76 

(46):668–669.

Trupe, C. H., K. G. Stewart, M. G. Adams, and J. P. 

Foudy. 2004. Deciphering the Grenville of the 

Southern Appalachians through evaluation of the postGrenville tectonic history in northwestern North 

Carolina. Pages 679–695 in Tollo, R. P., L. Corriveau, J. 

McLelland, and M. J. Bartholomew, editors.

Proterozoic tectonic evolution of the Grenville Orogen 

in North America. Memoir 197. Geological Society of 

America, Boulder, CO, USA.

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(http://globalchange.gov/publications/reports/scientifi

c-assessments/us-impacts) Accessed 23 August 2010.

Whittecar, G. R. and D. F. Duffy. 2000. Geomorphology 

and stratigraphy of late Cenozoic alluvial fans, Augusta 

County, Virginia, U.S.A. In Regolith in the Central and 

Southern Appalachians, eds. G. M. Clark, H. H. Mills, 

and J. S. Kite. Southeastern Geology 39 (3-4):259–279. 

Woodward, H. P. 1932. Geology and mineral resources 

of the Roanoke area of Virginia. Dissertation.

Columbia University, Teachers College, New York, 

New York, USA.

Zen, E-an. 1997a. The Seven-Storey River: 

Geomorphology of the Potomac River Channel 

Between Blockhouse Point, Maryland, and 

Georgetown, District of Columbia, With emphasis on 

the Gorge Complex Below Great Falls. Open-File 

Report 97-60. U.S. Geological Survey, Washington, 

D.C., USA.

Zen, E-an. 1997b. Channel Geometry and Strath Levels 

of the Potomac River Between Great Falls, Maryland 

and Hampshire, West Virginia. Open-File Report 97-

480. U.S. Geological Survey, Washington, D.C., USA.
36 NPS Geologic Resources Division 

Additional References

This section lists additional references, resources, and web sites that may be of use to 

resource managers. Web addresses are current as of May 2010

Geology of National Park Service Areas

National Park Service Geologic Resources Division 

(Lakewood, Colorado). http://nature.nps.gov/geology/

NPS Geologic Resources Inventory. 

http://www.nature.nps.gov/geology/inventory/gre_pu

blications.cfm

U.S. Geological Survey Geology of National Parks 

(includes 3D photographs). 

http://3dparks.wr.usgs.gov/

Harris, A. G., E. Tuttle, and S. D. Tuttle. 2003. Geology of 

National Parks. Sixth Edition. Kendall/Hunt 

Publishing Co., Dubuque, Iowa, USA.

Kiver, E. P. and D. V. Harris. 1999. Geology of U.S. 

parklands. John Wiley and Sons, Inc., New York, New 

York, USA.

Lillie, R. J. 2005. Parks and Plates: The geology of our 

national parks, monuments, and seashores. W.W. 

Norton and Co., New York, New York, USA.

[Geared for interpreters].

NPS Geoscientist-in-the-parks (GIP) internship and 

guest scientist program. 

http://www.nature.nps.gov/geology/gip/index.cfm

Resource Management/Legislation Documents

NPS 2006 Management Policies (Chapter 4; Natural 

Resource Management): 

http://www.nps.gov/policy/mp/policies.html#_Toc157

232681

NPS-75: Natural Resource Inventory and Monitoring 

Guideline: 

http://www.nature.nps.gov/nps75/nps75.pdf.

NPS Natural Resource Management Reference Manual 

#77: http://www.nature.nps.gov/Rm77/

Geologic Monitoring Manual

R. Young and L. Norby, editors. Geological 

Monitoring. Geological Society of America, Boulder, 

Colorado.

[Website under development]. Contact the Geologic 

Resources Division to obtain a copy.

NPS Technical Information Center (Denver, repository 

for technical (TIC) documents): http://etic.nps.gov/

Geological Survey Websites

U.S. Geological Survey: http://www.usgs.gov/

Geological Society of America: 

http://www.geosociety.org/

American Geological Institute: http://www.agiweb.org/

Association of American State Geologists: 

http://www.stategeologists.org/

Other Geology/Resource Management Tools

Bates, R. L. and J. A. Jackson, editors. American 

Geological Institute dictionary of geological terms (3rd 

Edition). Bantam Doubleday Dell Publishing Group, 

New York.

U.S. Geological Survey National Geologic Map Database 

(NGMDB): http://ngmdb.usgs.gov/

U.S. Geological Survey Geologic Names Lexicon 

(GEOLEX; geologic unit nomenclature and summary): 

http://ngmdb.usgs.gov/Geolex/geolex_home.html

U.S. Geological Survey Geographic Names Information 

System (GNIS; search for place names and geographic 

features, and plot them on topographic maps or aerial 

photos): http://gnis.usgs.gov/

U.S. Geological Survey GeoPDFs (download searchable 

PDFs of any topographic map in the United States): 

http://store.usgs.gov (click on “Map Locator”).

U.S. Geological Survey Publications Warehouse (many 

USGS publications are available online): 

http://pubs.usgs.gov

U.S. Geological Survey, description of physiographic 

provinces: http://tapestry.usgs.gov/Default.html
BOWA Geologic Resources Inventory Report 37

Appendix A: Overview of Digital Geologic Data

The following page is an overview of the digital geologic data for Booker T. Washington 

National Monument. For a poster-size PDF of this overview and complete digital data, 

please see the included CD or visit the Geologic Resources Inventory publications web

site: http://www.nature.nps.gov/geology/inventory/gre_publications.cfm.

The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and other 

information about those resources; and honors its special responsibilities to American Indians, Alaska Natives, and affiliated Island 

Communities. 

NPS 807/105489, August 2010 
National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 

1201 Oakridge Drive, Suite 150 

Fort Collins, CO 80525 

www.nature.nps.gov 

EXPERIENCE YOUR AMERICATM