A Guide for Using Soil and Weathering 

Profile Data in Chronosequence Studies 

of the Coastal Plain of the 

Eastern United States

U.S. GEOLOGICAL SURVEY BULLETIN 1589-D

Prepared in cooperation with the U.S. Department of 

Agriculture, Soil Conservation Service
AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY

Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the current-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Survey publications released prior to the current year are listed in the most recent annual "Price and Availability List." Publications 

that are listed in various U.S. Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and 

Availability List" are no longer available.

Prices of reports released to the open files are given in the listing "U.S. Geological Survey Open-File Reports," updated monthly, which is for sale in microfiche from the U.S. Geological Survey, Books and Open-File Reports Section, Federal Center, Box 

25425, Denver, CO 80225. Reports released through the NTIS may be obtained by writing to the National Technical Information 

Service, U.S. Department of Commerce, Springfield, VA 22161; please include NTIS report number with inquiry.

Order U.S. Geological Survey publications by mail or over the counter from the offices given below.

BY MAIL

 . OVER THE COUNTER 

Books

Books Professional Papers, Bulletins, Water-Supply Papers, Techniques

of Water-Resources Investigations, Circulars, publications of general in- Books of the U.S. Geological Survey are available over the

terest (such as leaflets, pamphlets, booklets), single copies of Earthquakes counter at the following Geological Survey Public Inquiries Offices, all

& Volcanoes, Preliminary Determination of Epicenters, and some mis- of which are authorized agents of the Superintendent of Documents:

cellaneous reports, including some of the foregoing series that have gone

out of print at the Superintendent of Documents, are obtainable by mail

from - WASHINGTON, D.C.-Main Interior Bldg., 2600 corridor,

18th and C Sts., NW.

U.S. Geological Survey, Books and Open-File Reports DENVER, Colorado-Federal Bldg., Rm. 169,1961 Stout St. 

Federal Center, Box 25425 LOS ANGELES, California-Federal Bldg., Rm. 7638,300 N. 

Denver, CO 80225 Los Angeles St.

- MENLO PARK, California-Bldg. 3 (Stop 533), Rm. 3128,

Subscriptions to periodicals (Earthquakes & Volcanoes and 345 Middlefield Rd.

Preliminary Determination of Epicenters) can be obtained ONLY from RESTON, Virginia-503 National Center, Rm. 1C402,12201 

the Sunrise Valley Dr.

- SALT LAKE CITY, Utah-Federal Bldg., Rm. 8105,125 

Superintendent of Documents South State St.

Government Printing Office SAN FRANCISCO, California-Customhouse, Rm. 504,555 

Washington, D.C. 20402 Battery St.

- SPOKANE, Washington-US. Courthouse, Rm. 678, West

(Check or money order must be payable to Superintendent of Docu- 920 Riverside Ave. 

ments.) - ANCHORAGE, Alaska-Rm. 101,4230 University Dr.

- ANCHORAGE, Alaska-Federal Bldg, Rm. E-146,701 C St.

Maps

For maps, address mail orders to

U.S. Geological Survey, Map Distribution Maps

Federal Center, Box 25286 Maps may ^ purchased over the counter at the U.S. GeologiDenver, CO 80225 cal Survey offices where books are sold (all addresses in above list) and

at the following Geological Survey offices: 

Residents of Alaska may order maps from

- ROLLA, Missouri-1400 Independence Rd. 

Alaska Distribution Section, U.S. Geological Survey, . DENVER, Colorado-Map Distribution, Bldg. 810, Federal

New Federal Building-Box 12 Center 

101 Twelfth Ave., Fairbanks, AK 99701 . FAIRBANKS, Alaska-New Federal Bldg., 101 Twelfth Ave.
Chapter D

A Guide for Using Soil and Weathering 

Profile Data in Chronosequence Studies 

of the Coastal Plain of the 

Eastern United States

By H.W. MARKEWICH, M.J. PAVICH, M.J. MAUSBACH, 

R.G. JOHNSON, and V.M. GONZALEZ

Prepared in cooperation with the U.S. Department of 

Agriculture, Soil Conservation Service

Physical and chemical data from Chronosequence studies in the 

Coastal Plain of the Eastern United States are summarized and 

interpreted, and suggestions are made as to the data needed 

for a nonstatistical use of soil and weathering profiles in 

determining surface ages

U.S. GEOLOGICAL SURVEY BULLETIN 1589

PEDOLOGIC STUDIES IN THE EASTERN UNITED STATES: RELATIONS TO GEOLOGY
DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, Jr., Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

Any use of trade, product, or firm names in 

this publication is for descriptive purposes 

only and does not imply endorsement by the 

U.S. Government

UNITED STATES GOVERNMENT PRINTING OFFICE: 1989

For sale by the

Books and Open-File Reports Section

U.S. Geological Survey

Federal Center, Box 25425

Denver, CO 80225

Library of Congress Cataloging in Publication Data

A guide for using soil and weathering profile data in chronosequence studies 

of the Coastal Plain of the Eastern United States

(Pedologic studies in the Eastern United States, relations to geology ; ch. D) 

(U.S. Geological Survey bulletin ; 1589-D)

Bibliography: p.

Supt. of Docs, no.: I 19.3:1589-D

1. Soil chronosequences Research United States Technique Handbooks, manuals, etc. 2. Soils United States Analysis Handbooks, 

manuals, etc. I. Markewich, Helaine W. II. Series: U.S. Geological 

Survey bulletin ; 1589-D.

QE75.B9 no. 1589-D. 557.3s [551.7'00974] 88-607915

[S599.A1]
PREFACE

Some geologic investigations of Quaternary deposits, especially in the conterminous United States, have attempted to use relative degrees of weathering and soil 

formation to establish chronosequences of glacial and (or) fluvial landforms. Most studies 

have been in the glacial terrane of the midcontinent and the Western United States. Few 

such studies have been conducted in the Eastern United States, especially in the 

unglaciated Middle Atlantic and Southeastern States.

From 1979 to 1984, the U.S. Geological Survey and the U.S. Department of 

Agriculture's Soil Conservation Service conducted cooperative regional studies of the 

relations between soils and geology in the Middle Atlantic and Southeastern States. The 

primary goal of the studies was to determine if soil properties could be used to estimate 

ages of associated landforms. Coral, wood fragments, and peat were sampled from 

constructional landforms of fluvial and marine origin in order to estimate ages by isotopic 

analyses; these ages were then related to regional biostratigraphic and lithostratigraphic 

correlations. Specific site investigations were conducted on Pliocene to Holocene marine 

and fluvial terraces in the Atlantic and eastern Gulf Coastal Plains and the Appalachian 

Piedmont. Soils on granite, schist, and quartzite parent rocks of the Appalachian 

Piedmont were sampled to test the use of soil properties as indicators of soil age. Each 

chapter of this bulletin series examines the relation of soils to geology in a specific 

geographic area.

The cooperative study involved research scientists from both agencies and field 

personnel from State offices of the Soil Conservation Service. Responsibility for sample 

analysis was divided between the Department of Agriculture's National Soil Survey 

Laboratory in Lincoln, Nebr., and the U.S. Geological Survey in Reston, Va. This report 

was prepared by scientists from both agencies who participated in specific site investigations or in studies of pedogenic processes.

Preface III

CONTENTS

Preface III 

Abstract Dl 

Introduction Dl

Acknowledgments D2 

Geologic and Physiographic Setting D2 

Climate D5

Weathering and Pedogenesis D5 

Weathering D5 

Pedogenesis D9

Field and Laboratory Methods Dll 

Discussion of Data D12

Data Comparison D12 

Weathering and Pedogenesis D14 

Parent Material D14 

Geomorphic Position D17 

Climate D19

Soil Chemistry and Mineralogy D22 

Conclusions D22 

References Cited D23 

Appendix D27

FIGURES

1. Maps showing:

A. Physiographic provinces of the Middle Atlantic and Southeastern United

States and subdivisions of the Piedmont lowlands D3 

B. Areas of soil sampling on a base map of major rivers of the Middle

Atlantic and Southeastern United States D4 

2A, 2B. Maps showing:

A. Daily maximum, average, minimum, and extreme temperatures for January and July for the Eastern United States D6 

B. Mean annual precipitation for the Eastern United States D8 

2C. Plots showing annual soil temperature and precipitation for sites in

Maryland, North Carolina, and Georgia and soil water balance for a site 

in North Carolina D9

ID. Map showing areal variation of average annual rainfall and runoff in Georgia, 1941-70 DIG 

3-8. Summary plots showing:

3. Depth of oxidation versus age of morphostratigraphic unit Dll

4. Thickness of solum versus age of unit D13

5. Thickness of argillic horizon versus age of unit D14

6. Clay mass versus age of unit D15

7. Rubification versus age of unit D16

8. Percentage of (Fe2O3+Al2O3 )/SiO2 versus age of unit D17

Contents
9. Summary plots of data from sola developed in 200-ka-old units showing: 

A. Thickness of solum versus maximum percentage of (Fe2O3 +Al2O3)/

SiO2 D18 

B. Clay mass versus maximum percentage of (Fe2O3 +Al2O3)/SiO2 D19

10. X-ray diffraction patterns showing clay mineral data for:

A. Pleistocene-age soils developed on marine terraces on the Delmarva

Peninsula and fluvial marine terraces of the Rappahannock River in

Virginia D20

B. Pliocene-age soil from Augusta, Ga. D21 

C. Holocene-age soil developed in the Alabama Coastal Plain D21

VI Contents
PEDOLOGIC STUDIES IN THE EASTERN UNITED STATES: RELATIONS TO GEOLOGY

A Guide for Using Soil and Weathering Profile Data in 

Chronosequence Studies of the Coastal Plain of the 

Eastern United States

By H.W. Markewich, 1 M.J. Pavich,2 M.J. Mausbach,3 R.G. Johnson,3 and V.M. Gonzalez2

Abstract

Data from soil and weathering profiles developed on 

constructional landforms in the Coastal Plain province of 

the Eastern United States indicate that there are positive 

correlations between specific physical and chemical properties of altered parent material and ages of associated 

landforms. Diagnostic properties of profiles developed on 

essentially unmodified constructional surfaces include 

depth of oxidation, percentage of labile minerals, thickness of solum, thickness of argillic horizon, clay mass, clay 

mineralogy, rubification, iron chemistry, and bulk chemistry. The depth of oxidation, the thickness of the solum, 

and the total thickness of the argillic horizon increase with 

the age of the landform. The percentage of labile minerals 

decreases with age and increases with depth from the 

surface. With increasing age, a complex clay mineral suite 

is replaced by a mineral assemblage dominated by kaolinite. (Fe2O3 +AI2 O3)/SiO2 shows a linear trend with the 

percentage of clay, the thickness of the solum, and the 

intensity of rubification. The weight percentage of SiO2 

and the clay mass increase with age in profiles younger 

than 1 Ma; SiO2 decreases with age in profiles older than 

1 Ma.

Pedons developed on the least-modified positions of 

morphostratigraphic units of fluvial and marine origin are 

described and sampled. Ages of these morphostratigraphic units have been determined by biostratigraphic 

and lithostratigraphic correlations and by isotopic analyses. The oldest recognizable morphostratigraphic units 

are estimated to be latest Miocene in age. Measurements 

of properties of the soil and weathering profiles associated with these morphostratigraphic units reflect the 

length of time that the surface has been exposed to 

subaerial alteration. Any age determined by these measurements is a minimum. Reliability and refinement of 

soil, and therefore of surface, age are dependent on the 

degree of modification of the surface, the number of

Manuscript approved for publication March 28, 1989. 

'U.S. Geological Survey, Doraville, GA 30360. 

2U.S. Geological Survey, Reston, VA 22092. 

3U.S. Department of Agriculture, Soil Conservation Service, Lincoln, NB 68508-3866.

profiles sampled per surface, and the number and type of 

analyses performed. There is an inverse relation between 

soil (surface) age and pedon variability, the younger 

surfaces showing more variability in pedon characteristics 

than the older surfaces do.

INTRODUCTION

In the United States, chronosequence studies that use 

the degree of soil development as a means of establishing 

relative ages of surfaces and (or) associated parent material 

traditionally have been restricted to glaciated and (or) 

loess-covered terranes of the midcontinent and the alpine 

West. In the past 10 years, there has been an increase in the 

number of soil chronosequence studies in the unglaciated 

river valleys and marine terraces of California (Birkeland 

and others, 1987; Harden, 1987; Harden and others, 1986; 

Muhs, 1982; McFadden and Weldon, 1987), in the intermontane basins of the Western United States (Reheis, 

1987), and in the loess-covered deltaic sequences of the 

lower Mississippi Valley (B.J. Miller, J.C. Lewis, J.J. 

Alford, and W.J. Day, unpublished field trip guidebook, 

1982; Miller, in press). Regardless of the terrane, most data 

generated by these studies pertain to soils that are developed 

on parent materials younger than 1 Ma.

The predominantly offlap sequence of upper Cenozoic sediments of the Coastal Plain of the Eastern United 

States provides the opportunity to study soil and weathering 

profiles in the context of time or as chronosequences. This 

report summarizes data that have been generated through 

the study of such profiles developed on constructional 

landforms that are mappable morphostratigraphic units in 

the Atlantic Coastal Plain physiographic province of the 

Eastern United States. These morphostratigraphic units 

range in age from several thousand to several million years. 

These data can be quantified, as Harden (1982) has demonstrated with soils data elsewhere, and they can be 

valuable tools for the field geologist in establishing both 

relative and absolute ages of constructional morphostratigraphic units in a field area. The data also show that soil

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D1
properties continue to change as long as pedogenic processes (geochemical and biogeochemical reactions) are 

active and soil is not removed by erosion.

The combination of adequate regional and local 

geologic mapping and numerous age determinations provides the basis on which personnel of the U.S. Geological 

Survey (USGS) and the Soil Conservation Service (SCS) 

undertook this long-term cooperative project. Its overall 

purpose was to study the properties of soil and weathering 

profiles developed in the Piedmont and Coastal Plain 

provinces of the Eastern United States. The results of this 

effort are being published as a series of chapters in USGS 

Bulletin 1589 (Markewich and others, 1986, 1987a, 1988). 

This chapter summarizes data from the Coastal Plain 

province and compares those data with other available 

published and unpublished data for the same region.

The primary purpose of this chapter is to present 

systematically obtained field and laboratory data from soil 

and weathering profiles4 developed from deposits of known 

age and from morphostratigraphic units for which orderof-magnitude age estimates can be made on the basis of 

biostratigraphic or morphostratigraphic correlation. Rather 

than precisely defining the age relations of soil properties, 

its intention is to demonstrate that systematically assembled 

soil data do show age-related trends. Although this chapter 

is not a primer on soils for field geologists mapping upper 

Cenozoic deposits, its secondary purpose is to demonstrate 

the utility of "low-tech" data that can be easily obtained in 

the course of mapping or stratigraphic studies. Soil and 

weathering profile data are invaluable sources of information in age correlation and in reconstruction of the geologic 

and paleoclimatic history of an area such as the Coastal 

Plain of the Eastern United States.

Data presentation in this report follows the format of 

soil chronofunction data presented by Bockheim (1980), 

who compiled analyses of the changes of soil properties 

with time in the framework of the chronofunction as first 

defined by Jenny (1941). Bockheim's two major findings 

were (1) that the equation Y=a+(b log X) yielded the best 

correlation between soil properties and time and (2) that 

changes in some soil properties do not necessarily reach a 

steady state, as Nikiforoff (1949) suggested. Bockheim 

showed that soil properties plotted against the log of time 

provide statistically significant functions. Data herein are 

presented graphically so that they can be easily used by 

geologists and soil scientists in estimating ages of morphostratigraphic units in their field areas. These data do not 

come from a specific chronosequence, nor do they represent 

all types of analyses that could be valuable in a chronosequence study. They do, however, represent the simplest

soil in this study comprises the A and B horizons, referred to 

as solum by pedologists. The weathering profile includes the solum and the 

subjacent C horizon or parent material altered by oxidation, hydration, and 

other chemical weathering processes.

and, currently, the most reliable techniques for determining 

soil age relations for constructional surfaces in the Coastal 

Plain of the Eastern United States. The "Introduction" 

includes discussions of factors important in establishing 

chronosequences. Data for comparisons are presented 

graphically in "Discussion of Data."

Acknowledgments

We would like to express our appreciation to J.P. 

Owens, R.B. Mixon, and J.T. Hack of the U.S. Geological 

Survey and to R.A. Daniels and Klaus Flach of the U.S. 

Department of Agriculture's Soil Conservation Service for 

their initiative in suggesting a cooperative project between 

the two agencies and for their encouragement throughout 

the study period. We also extend our thanks to the State Soil 

Scientists of Virginia, North Carolina, South Carolina, and 

Alabama for their assistance in the field and for the 

participation of Soil Conservation Service field personnel in 

sampling the study profiles. The paper benefited greatly 

from discussions with the late B.J. Miller, professor of 

agronomy at Louisiana State University in Baton Rouge, 

La.

Geologic and Physiographic Setting

The major physiographic provinces of the United 

States are shown in figure 1A. This study pertains to the 

Coastal Plain, the largest single physiographic province in 

the Eastern United States. Strata of the Coastal Plain of the 

Eastern United States consist of a series of gently seaward 

dipping marine and fluvial sediments that range in age from 

Early Cretaceous through Holocene. The lower Coastal 

Plain, specifically that part of the province less than 80 m in 

altitude, has post-middle Miocene to Holocene alluvial and 

marine strata exposed at the surface. Much of the middle 

and southeastern Atlantic Coastal Plain has been mapped in 

sufficient detail to regionally correlate the Quaternary 

strata. Isotopic, biostratigraphic, and lithostratigraphic 

analyses have provided a probable range of ages for many 

of the marine units (Blackwelder and Ward, 1979; Owens 

and Denny, 1979; Owens and Minard, 1979; Cronin and 

Hazel, 1980; Cronin and others, 1984; DuBar and others, 

1980; McCartan and others, 1982, 1984; Mixon and others, 

1982; Hazel, 1983; Mixon, 1985; Owens, 1989). Limited 

data are also available from alluvial terraces in both the 

Atlantic Coastal Plain and the eastern Gulf Coastal Plain 

(Markewich and Christopher, 1982; Colman, 1983; Mixon 

and others, 1989; Markewich, 1985; Seller, 1988).

Physiographically, the Atlantic Coastal Plain from 

New York through Georgia is a seaward-sloping plane 

about 1,600 km long and having a maximum altitude of 230 

to 245 m and a maximum relief of 60 to 90 m. It is bounded

D2 Pedologic Studies in the Eastern United States
32

' "xi t>

L

//; /w//^

20C MILES 

J

100 200 KILOMETERS

EXPLANATION

TALLAPOOSA-RAPPAHANNOCK LINE 

SUBDIVISIONS OF PIEDMONT LOWLANDS

CA Carolina slate belt

UW Uwharrie Mountains

M Mesozoic basins

OP Outer Piedmont of North Carolina and Virginia

KM Kings Mountain belt

PM Pine Mountain belt

Figure 1 A. Physiographic provinces of the Middle Atlantic and Southeastern United States and subdivisions of the 

Piedmont lowlands (from Hack, 1982). Stipple pattern denotes Mesozoic basins in the Piedmont lowlands. The 

Tallapoosa-Rappahannock line separates areas of higher and lower relief in the Piedmont physiographic province.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D3
42 Q

34°

32°

EXPLANATION

ATLANTIC-GULF DIVIDE 

TALLAPOOSA-RAPPAHANNOCK LINE

0 100 200 MILES

100

~I 

200 KILOMETERS

Figure IB. Areas of soil sampling on a base map of 

major rivers of the Middle Atlantic and Southeastern 

United States (from Hack, 1982). Shaded area indicates 

Appalachian highlands. Sampling areas, shown by dark 

rectangles, are identified by letters, which correlate 

with those used in figures 3 through 9 and in the 

appendix. Rivers are identified by number: 1, Delaware; 2, Schuylkill; 3, Susquehanna; 4, Patapsco;

5, Potomac; 6, Rappahannock; 7, James; 8, Appomattox; 9, Meherrin; 10, Roanoke; 10a, Dan; 11, Neuse; 

12, Cape Fear; 12a, Deep; 12b, Haw; 13, Yadkin; 14, 

Catawba; 15, Broad; 16, Saluda; 17, Savannah; 18, 

Oconee; 19, Ocmulgee; 20, Flint; 21, Chattahoochee; 

22, Tallapoosa; 23, Coosa; 24, New; 25, French Broad; 

26, Tuckasegee; 27, Hiwassee; 28, Etowah; 29, 

Tennessee.

D4 Pedologic Studies in the Eastern United States
on the east by the Atlantic Ocean and on the south by the 

Gulf of Mexico. The late Cenozoic strata of the lower 

Coastal Plain underlie numerous constructional landforms, 

such as alluvial terraces and barrier-back-barrier systems, 

that can be mapped as morphostratigraphic units (Thorn, 

1967a; Daniels and others, 1971, 1978; Owens and Denny, 

1979; Owens and Minard, 1979; McCartan and others, 

1984; Mixon, 1985; Mixon and others, 1989; Owens, 

1989). Coastal Plain streams are of three types: (1) those 

that drain the Blue Ridge and (or) Valley and Ridge, 

Piedmont, and Coastal Plain physiographic provinces; (2) 

those that drain only the Piedmont and Coastal Plain 

provinces, and (3) those that drain only the Coastal Plain 

(fig. 15). Provenances are similar enough to allow comparison of alluvial terraces among like drainage types.

Climate

The Coastal Plain of the Eastern United States 

(excluding Florida) extends from lat 30° to 40° N. and has 

a humid subtropical to humid temperate climate (fig. 2A). 

South of Maryland, the Coastal Plain is in the thermic soil 

temperature regime (that is, the mean annual soil temperature ranges from 15 °C to 22 °C at a depth of 50 cm, and the 

difference between mean summer and mean winter soil 

temperatures is greater than 5 °C) (fig. 2C). The northern 

part of the Coastal Plain, from Maryland to New York, is in 

the mesic soil temperature regime (that is, the mean annual 

soil temperature ranges from 8 °C to 15 °C at a depth of 50 

cm, and the difference between mean summer and mean 

winter soil temperatures is greater than 5 °C).

The Coastal Plain is in the udic soil moisture regime 

(that is, in most years, the soil moisture control section is 

not dry in any part for as long as 90 days, cumulative). 

Rainfall is seasonal in the Coastal Plain of the Eastern 

United States; evapotranspiration is greater than precipitation for a minimum of 3 months a year.

Preliminary data from numerous research projects in 

various aspects of the agricultural sciences suggest that 

climatic variations in the Coastal Plain contribute to differences in the degree of weathering and in the degree of 

pedogenic development in parent materials of similar ages 

and having similar histories of subaerial exposure. In 

Maryland, at the northern end of the study area, soil 

temperatures (at a depth of 50 cm) range seasonally from 2 

°C to 25 °C (Miller, 1974), the annual mean being 16 °C. 

These soil temperatures were taken over a 1-year interval. 

Study sites are located in Monmouth fine sandy loam at 

Upper Marlboro, Md. In southwestern Georgia, detailed 

soil temperature data are taken from Ultisols in a peanut 

field that was monitored for a USGS-Environmental Protection Agency cooperative study on pesticide migration. 

These soil temperature data range from 6 °C to 29 °C, the 

annual mean being 22 °C. The measurements were periodic

(about three observations a week) recorded over a 3-year 

interval (S.C. Cooper, written communication, 1986). 

Since many pedologic processes are temperature dependent, 

it is significant to note that, even at a depth of 114 cm, the 

soil temperatures in southwestern Georgia are greater than 

20 °C for 6 months of the year.

Variation in precipitation and in the seasonality of 

precipitation is extremely important in both weathering and 

pedogenic development. Precipitation in the Coastal Plain 

of the Eastern United States ranges from 1,000 to 1,600 

mm/yr (Nichols and others, 1985) (fig. 25). Seasonality of 

precipitation varies from 100 percent of total precipitation 

as rain in southern Georgia to 90 percent as rain and 10 

percent as snow in Maryland. Both total precipitation and 

runoff have significant spatial variability in the Coastal 

Plain. (Fig. 2D shows the variability of these parameters for 

the State of Georgia.) Figure 2B shows the variability of 

precipitation for the entire Coastal Plain.

Differences in the physical and chemical characteristics of well-drained Coastal Plain soils developed in similar 

parent materials in similar geomorphic positions appear to 

be related to latitudinal position. Data suggest the presence 

of a transition zone between North Carolina and South 

Carolina. Weathering and soil development appear to have 

proceeded at a more rapid rate south of this transition zone. 

Profiles of similar ages, developed in lithologically similar 

parent materials, are more deeply oxidized and have greater 

solum thicknesses in South Carolina and Georgia than do 

their counterparts in Virginia and Maryland. Comparison of 

soil temperature data from southwestern Georgia and Maryland suggests that climatic causes for these variations 

probably include a higher mean annual soil temperature, a 

longer period of time each year during which mean annual 

soil temperatures are above 25 °C, a higher mean summer 

soil temperature, and higher mean soil temperatures at 

greater depths. In addition, comparison of runoff and 

rainfall (fig. 2D) suggests a very high loss of soil moisture 

by evapotranspiration in the more southerly States.

Weathering and Pedogenesis

Weathering

Weathering is generally considered to be the physical 

disintegration and chemical alteration of rock or unconsolidated sediments at or near the Earth's surface. The exact 

limits on the depth to which weathering occurs and on the 

types of processes included in the general term "weathering" are usually arbitrarily defined for a given region. There 

is, however, a consensus that weathering is a collective 

term for Earth-surface-temperature biogeochemical and 

physical processes (usually at pH<7 and Eh>0) that occur 

as a result of the subaerial exposure of rock-forming 

minerals to ground water.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D5
50°

95 1 90° 8V 80° 75°

Figure 2A. Daily maximum, average, minimum, and extreme temperatures (in degrees Fahrenheit) for January and

D6 Pedologic Studies in the Eastern United States
t

f NEW ORLEANS 

92_J___________04 VD ^ 

83-^ ^-SoV ^ 

74 ^V^

30° -

25°

95° 90°

July for the Eastern United States (from Ruffner and Bair, 1977).

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D7
TOTAL 

INCHES CENTIMETERS

SCALE 1:17,000,000 

100 200 300 400 MILES 

_I

200 400 KILOMETERS

203.2

162.6

121.9

81.3

61.0

40.6

Figure 28. Mean annual precipitation for the Eastern United States (from U.S. Geological Survey, 1970).

In the Coastal Plain of the Eastern United States, the 

dominant process involved in weathering is leaching or 

chemical dissolution by acidic, oxygenated rain and (or) 

ground water. This dominance of chemical processes in

postdepositional alteration of sediments of the Coastal Plain 

of the Eastern United States (Owens and others, 1983) is the 

result of a humid temperate to subtropical climate in an area 

of relatively low relief (0-70 m/100 km2), limited local

D8 Pedologic Studies in the Eastern United States
Climatic data

JFMAMJJASOND 

°C mm

30 250 - 

20 200 - 

10 150 -

0 100

-10 50 -

-20 0

Precipitation

Aerie Fragiaquult, Prince Georges County, Maryland

Climatic data and soil water balance

JFMAMJJASOND

in °F °C mm

10 86 30 250 - 

 8 68 20 200 

4 32

 2 14 -10 50 -

Temperature

0-4 - 20 0

in. °F 

k- 10 86

0-4

U utilization D. deficit R. recharge S. surplus

Precipitation Potential Evaporation Temperature 

Plinthic Paleudult, Johnston County, North Carolina

Climatic data

JFMAMJJASON 

°C mm

30 250 -

20 200 - 

10 150 - 

0 100 -

-10 50 -

-20 0

Precipitation

Typic Umbraquult, Craven County, North Carolina

JFMAMJ JASOND

 Temperature Precipitation Temperature

Aerie Haploquod, Brantley County, Georgia

Figure 2C. Annual soil temperature and precipitation for sites in Maryland, North Carolina, and Georgia and soil water 

balance for a site in North Carolina (from Soil Survey Staff, 1975).

tectonics, and slow regional uplift (10-20 m/Ma). (Prowell 

(1988) has summarized tectonism in the Atlantic Coastal 

Plain region.) The rapid chemical alteration of parent 

material and the concomitant soil development result in a 

blanket of surficial material that has remnant characteristics 

of the original parent material and weathering characteristics that can be described and geochemically analyzed. 

Comparing units having similar origins but differing ages 

can provide a means of estimating relative ages and orderof-magnitude "absolute" ages for surficial units where other 

age-determining techniques are not applicable.

Owens and others (1983) and Seller (1988) have 

provided the only studies relating the degree of postdepositional weathering to compositional maturity and formation 

age. Other data are measurements of physical parameters 

that can be determined in the field. Many of the published 

and unpublished data on depth of weathering in the Coastal 

Plain are measurements of the depths of oxidation (Thorn, 

1967a, b; McCartan and others, 1984; H.W. Markewich,

unpublished data, 1983-85). These data are summarized in 

figure 3.

Pedogenesis

Soil development or pedogenesis from a geologic 

perspective is in large part the result of dissolution of 

minerals in the parent material (for example, weathered 

rock or sediment), simultaneous formation of new minerals 

composed of the less soluble elements released from parent 

minerals, and physical rearrangement of the parent fabric 

and structure into soil fabric and structure. In the middle 

and lower Coastal Plain of the Eastern United States, soil 

development follows one of two distinctly different pathways, depending on parent material and local drainage. The 

less common pathway, occurring in very well sorted quartz 

sand, is toward development of a Spodosol (or of a spodic 

Ultisol) under conditions of low pH and high water table. 

The other, more common pathway in less well sorted

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D9
EXPLANATION

52(i32i LINE OF EQUAL AVERAGE ANNUAL RAINFALL 

1941_70_Interval 2 inches

 2015V LINE OF EQUAL RUNOFF Interval 2 inches, 

4 inches above 20-inch line

PHYSIOGRAPHIC PROVINCE BOUNDARY - 

Dashed to indicate boundary between upper 

and lower Coastal Plains of Georgia

0 10 20 30 40 KILOMETERS

Figure 2D. Areal variation of average annual rainfall (solid lines) and runoff (dashed lines) in Georgia, 1941-70 (from Carter and Stiles, 

1983). Values shown in parentheses are millimeters.

sediment of mixed mineralogy is toward an Ultisol in which Coastal Plain soils that exhibit argillic horizons and

a well-defined E horizon overlies an argillic B horizon that that have developed on constructional landforms in sediis commonly difficult to subdivide. ments of mixed mineralogy and poorly sorted particle-size

D10 Pedologic Studies in the Eastern United States
C/)

DC 20 

LU1- 

LJJ

^ 18

Z

z 16

o

^^ 1 4. ^T

Q

o 12

LJ_

0 10

I

ft] 8 

Q

6

4

2

n

SAMPLING AREA

A Delmarva Peninsula

B Rappahannock Valley

C Cape Fear Valley, NC

D Henry and Marion

Counties, SC

~~ E Charleston, SC

F Augusta, GA 

 G Pine Mountain, GA

H Uphapee Creek, AL

 | » Indicate minima

-

-

_

~ V *

v a

i i i 

EXPLANATION

SYMBOL DATA SOURCE

O Markewich and others (1987)

 Markewich and others (1987)

 H.W. Markewich and others (unpublished data, 1980)

D Thorn (1967a,b)

V McCartan and others (1984) ~~

D Pavich and others (1981) t 

A H.W. Markewich and others (unpublished data, 1984) A 

T Markewich and others (1988)

-

i '

A 

V V >

I i IA -

i

D V O

A B *

I ° ° I I

103

10" 105 106

AGE OF MORPHOSTRATIGRAPHIC UNIT, IN YEARS

107

Figure 3.

Data for

Depth of oxidation versus age of morphostratigraphic unit. Data are based on field exposures and drill holes. 

sampling areas A through H are given in the appendix.

distribution are ideal for chronosequence studies. Soil 

development or evolution appears to progress from Inceptisol to Alfisol to Ultisol (which goes from Hapludult to 

Paleudult); this progression roughly corresponds to the 

increasing age of soil and the associated morphostratigraphic unit. Data suggest that quartzose or siliceous soils 

are extremely difficult to adequately describe and analyze 

and cannot easily be compared with soils of mixed mineralogy (Markewich and others, 1986). However, siliceous 

soils, which are commonly associated with marine barrier 

deposits, can be compared to one another and are discussed 

elsewhere (Markewich and others, 1986). Available published and unpublished data from argillic Coastal Plain soils 

developed in sediments of mixed mineralogy are summarized in figures 3 through 10. Published data used in 

constructing these figures are summarized in the appendix. 

Interpretations of the data and suggested limitations on the 

use of those data are discussed in "Data Comparison" on 

p. D12.

Field and Laboratory Methods

Chronosequence studies ideally should include at 

least three morphostratigraphic units that differ in age but 

have similar forms and origins. In the Coastal Plain province of the Eastern United States (fig. 1), the units most 

suited to chronosequence studies are alluvial terraces. There 

is enough similarity in terrace sediment provenances within 

subprovinces of the Coastal Plain that weathering and 

pedologic data can be compared between drainages (for 

example, between the Cape Fear and Savannah Rivers in 

fig. IB). Morphostratigraphic features of marine origin, 

such as barrier-back-barrier systems, are more difficult to 

delineate and are spatially distributed over a much greater 

area than are alluvial terraces. Commonly, however, the 

greater the size of the feature, the greater the variation in 

parent material, in depth and type of weathering, and in 

degree and type of pedogenic development. Therefore, the 

number of samples needed to adequately characterize

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D11
morphostratigraphic units of marine origin is greater than 

the number needed to characterize those that are fluvial in 

origin.

Wherever possible, soil and weathering profiles 

should be described and sampled as one continuous exposure (trench, core, outcrop, borrow pit, and so on). If an 

exposed cut face of a roadcut or borrow pit is used, then at 

least 0.5 m of material should be removed from the face 

before samples are taken to ensure that conditions are 

similar for those pedons sampled from recently opened 

trenches or from core and for those that have been exposed 

at the surface for a considerable length of time.

If the thickness of the sola or the depth of weathering 

exceeds 3 m, then backhoe excavation will not be adequate 

to obtain a complete profile. (This situation is common for 

morphostratigraphic units older than 1 Ma.) Several closely 

spaced, undisturbed cores should be obtained to acquire a 

volume of sample adequate for field description and laboratory analyses.

Profiles should be described and samples taken from 

several different topographic positions on the landform. 

These positions should include the middle of the upper 

surface of the landform (for example, near the drainage 

divide) and a place near but not on the edge of the landform. 

Obvious poorly drained low spots or closed depressions 

should be avoided.

Field descriptions of soil and weathering profiles such 

as those presented by Markewich and others (1986, 1987a, 

1988) should include the following observations:

1. Soil horizonization, including structure, texture, 

color, clay skins, silt coatings, CaCO3 content, mineralogy 

of sand-sized and coarser fractions, nodules, plinthite, 

pans, and mottles (see appendix for examples).

2. Position of water table, if evident.

3. Position on the landscape (interfluve, side slope, 

bottomland, and so on).

4. Surface modifications such as windblown sand 

(dunes and (or) sand sheets), periglacial features, closed 

depressions, and so on.

5. Depth of oxidation.

6. Layers of iron oxide, calcium carbonate, or calcium sulfate accumulation below the solum.

7. Detailed description of parent material(s), including mineralogy, fabric and foliation, and so on.

8. Estimate of the age(s) of soil and (or) parent 

material and a short explanation of the importance of the 

morphostratigraphic unit in understanding the geologic 

history of the area.

Laboratory analyses should include the following:

1. Particle-size distribution.

2. Clay mineralogy by X-ray diffraction.

3. Mineralogy of the heavy and light components of 

the very fine sand-sized fraction.

4. Bulk chemistry.

Standard laboratory soil characterization data (for 

example, cation exchange capacity, pH, water retention, 

and so on), differential thermal analysis, and trace-element 

analyses are not necessary for age comparisons but may be 

desirable for studies in weathering and soil-forming processes. Other laboratory data (see appendix) and X-ray 

diffraction are used in constructing figures 6, 8, 9, and 10.

DISCUSSION OF DATA

Data Comparison

Three requirements must be met before comparing 

soil and weathering profile data from constructional landforms in an eroding subaerial environment. The first 

requirement is that, at the highest uneroded positions on a 

morphostratigraphic unit, the rates5 of chemical weathering 

and soil formation are greater than the rate of erosion for 

time periods approaching the total residence time of the 

depositional unit. The second requirement is that, in similar 

positions on similar morphostratigraphic units, the dominant processes active in weathering and soil formation are 

also similar. The third requirement is that pedogenic and 

weathering processes are continuous through time. For 

example, Daniels and others (1975b) noted that a change of 

drainage due to headward erosion changed the dominant 

processes affecting the distribution of iron. Observations in 

many areas indicate that sediments become more weathered 

(for example, rubification and depth of oxidation increase) 

and that soils become more developed the longer the 

morphostratigraphic unit is exposed to subaerial alteration. 

There is an undefined time limit or an unidentified position 

in the regional landscape at which the erosion rate accelerates and removes the entire unit.

Figures 3 through 8 show that a number of processes 

involved in weathering and soil formation are active 

through time. The slopes of the plots suggest that these soils 

continue to alter chemically and do not reach a static 

condition at any period of formation. The increase of hue 

(or rubification) through time (fig. 7) indicates the continuous formation and accumulation of iron oxyhydroxides in 

the solum. Data also indicate increases in the depth of 

oxidation (fig. 3), in the thickness of the solum (fig. 4), in 

the thickness of the argillic horizon (fig. 5), and in the clay 

mass (grams of clay per square centimeter of solum) (fig. 

6) with increasing age of the morphostratigraphic unit. 

These parameters provide several means of estimating the 

rate(s) of parent material alteration throughout the late

5The rate of soil formation or erosion can be expressed in units of 

length-time (that is, in centimeters per year beneath the original surface) or 

mass/area-time (that is, mass of soil component summed through a unit 

area of the solum normal to the soil surface). These two parameters are 

related by bulk density (mass/volume): cm/yr x mass/cm3 =mass/cm2-yr.

D12 Pedologic Studies in the Eastern United States
700

600

500

400

300

y 200

X

100

SAMPLING AREA

A Delmarva Peninsula 

B Rappahannock Valley 

C Cape Fear Valley, NC 

F Augusta, GA 

G Pine Mountain, GA 

H Uphapee Creek, AL

I » Indicate minima

EXPLANATION 

SYMBOL DATA SOURCE

Markewich and others (1987)

Markewich and others (1987)

H.W. Markewich and others (unpublished data, 1980)

Pavich and others (1981)

H.W. Markewich and others (unpublished data, 1984)

Markewich and others (1988)

103

10" 105 106

AGE OF MORPHOSTRATIGRAPHIC UNIT, IN YEARS

107

Figure 4. Thickness of solum versus age of unit. The solum comprises the A and B horizons of the weathering profile. 

Thicknesses were measured on outcrops or in backhoe excavations. Minima are indicated where the base of the B 

horizon was not reached in sampling. Data for sampling areas A through C and F through H are given in the appendix.

Cenozoic. The data have not been treated statistically by 

regression analysis because of the small number of pedons 

sampled and the age uncertainties. Continued investigations 

may provide enough data for rigorous statistical analysis. 

Switzer and others (1988) have discussed appropriate statistical methods.

These graphs can be considered to be only semiquantitative because of uncertainties about absolute ages and, in 

some cases, because of incomplete exposure of the entire 

weathering profile. For example, depth of oxidation values 

(fig. 3) are minima estimated or measured on outcrops, 

cores, or borings for chromas greater than four and (or) hues 

redder than 10YR. Where an age range is used for the age 

of a depositional unit or soil, the point is plotted in the 

middle of that age range. For example, the Joynes Neck site 

(area A, fig. IB; A-2, appendix) may range from 60 to 125 

ka (Mixon, 1985). It is plotted at 92.5 ka. The purpose of 

this plot is to show that the depth of oxidation increases with 

each order-of-magnitude change in age. As Bockheim 

(1980) discussed, climate also appears to have a significant 

effect on the depth of oxidation.

A detailed comparison of the data has shown that 

local variations in parent material, drainage, and landscape 

position correlate with differences in soil and weathering 

profiles (Markewich and others, 1986, 1987a, 1988). Figures 9A and B show solum thickness and clay mass plotted 

against maximum (Fe2O3 +Al2O3 )/SiO2 for several 200-ka 

units and thus show the range of values for profiles 

developed at different sites under different drainage conditions. The variance in these values shows that, before soil 

and weathering profiles can be used to estimate relative or 

absolute age, several sites must be compared to adequately 

characterize the unit. Knowledge of regional stratigraphy 

and local geologic setting is needed to accurately interpret the derived data.

Clay mineral data, summarized in figures 10A, B, and 

C, indicate that in situ formation of soil clay minerals is a 

dominant process in the formation of argillic horizons. The 

formation of clay by alteration of aluminosilicate parent 

minerals occurs simultaneously with illuviation. In situ 

formation of clay is indicated by the dominance of 

pedogenic 14-A hydroxyinterlayered vermiculite in the

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D13
o

N

E 4 

O

X

(J

DC 3

SAMPLING AREA

A Delmarva Peninsula 

B Rappahannock Valley 

C Cape Fear Valley, NC 

F Augusta, GA 

G Pine Mountain, GA 

H Uphapee Creek, AL

\ > Indicate minima

EXPLANATION 

SYMBOL DATA SOURCE

Markewich and others (1987)

Markewich and others (1987)

H.W. Markewich and others (unpublished data, 1980)

Pavich and others (1981)

H.W. Markewich and others (unpublished data, 1984)

Markewich and others (1988)

i

103 104 106 106 

AGE OF MORPHOSTRATIGRAPHIC UNIT, IN YEARS

107

Figure 5. Thickness of argillic horizon versus age of unit. Argillic horizons are B (Bt) horizons as defined by the Soil 

Survey Staff (1975). Data for sampling areas A through C and F through H are given in the appendix.

soil and in the upper part of the weathering profiles (profile 

A-3, fig. 10A). Mineralogy of the clay fraction changes 

from a more complex mixed mineralogy (kaolinite, vermiculite, and gibbsite) to a simpler, dominantly kaolinitic 

mineralogy through time. This transition in the mineralogy 

of the clay fraction is particularly evident in soils 1 Ma old 

or older (compare profiles B-2 and B-3, fig. 10A).

Weathering and Pedogenesis

Comparison of measured physical and chemical 

parameters of soil and weathering profiles is a useful tool in 

estimating the ages of morphostratigraphic units on the 

Coastal Plain of the Eastern United States. Comparisons are 

valid if data are from units that (1) are composed of similar 

parent materials, (2) are in similar positions in the local 

landscape, and (3) have developed under similar climatic 

conditions. The following three sections discuss some of the 

effects that these factors can have on the pedogenic development of Coastal Plain soils.

Parent Material

Quartz sand. Composition of the parent material is 

an important component in both the rate and the type of 

weathering and pedogenesis. Particularly important in 

Coastal Plain soils is the percentage of quartz sand in the 

parent material and the homogeneity of sorting of the unit. 

For example, a thick (more than 3 m) surface unit consisting 

of nearly pure quartz sand can weather rapidly and have no 

pedogenic development other than lamellae or staining 

caused by iron oxyhydroxides. Weathering of extremely 

permeable quartz sand commonly results in Entisols (commonly Psamments or Grosspsamments) or Ultisols of low 

clay content developed on surfaces that are older than 1 Ma 

(Markewich and others, 1986; Soil Survey Staff, 1975). 

Commonly, soils older than 1 Ma have been mapped as 

Ultisols exhibiting sandy surficial horizons. These soils can 

be representative of the few meters at the surface of a much 

more deeply weathered unit (see Gamble (1965) and 

Markewich and others (1986) for data from soils having 

these characteristics).

D14 Pedologic Studies in the Eastern United States
300

UJ

o

UJ 

DC

O 200

DC 

UJ

ex.

to

CO

< 100

SAMPLING AREA

A Delmarva Peninsula 

B Rappahannock Valley 

C Cape Fear Valley, NC 

F Augusta, GA 

G Pine Mountain, GA 

H Uphapee Creek, AL

I > Indicate minima

EXPLANATION

SYMBOL DATA SOURCE

O Markewich and others (1987)

 Markewich and others (1987)

 H.W. Markewich and others (unpublished data, 1980)

D Pavich and others (1981)

A H.W. Markewich and others (unpublished data, 1984)

V Markewich and others (1988)

i

8 %

103 1C4 105 106

AGE OF MORPHOSTRATIGRAPHIC UNIT, IN YEARS

107

Figure 6. Clay mass versus age of unit. Clay mass (measured in grams of clay per square centimeter) is the product of 

the bulk density (measured in grams per cubic centimeter) times the percentage of clay times the thickness of the 

horizon from each horizon of the Bt in the solum. Minima are given where the base of the Bt was not reached during 

sampling. Data for sampling areas A through C and F through H are given in the appendix.

The percentage of very fine sand-sized quartz is 

important to the formation of silt-sized and coarse claysized quartz in the soil. Numerous articles have been written 

on the pedogenic origin of quartz silt (Vita-Finzi and 

Smalley, 1970; Pye, 1983; Nahon and Trompette, 1982; 

M.J. Pavich, unpublished data, 1982). There has also been 

some discussion in the literature on whether the formation 

of silt-sized quartz is an important process in the development of argillic horizons (Markewich and others, 1987a) and 

(or) whether the presence of significant amounts of silt- and 

clay-sized quartz in a profile is indicative of eolian activity 

(Foss and others, 1978; Soller, 1988).

Interlayered sand and clay. Clay interlayers in 

marine terrace sediments commonly restrict the downward 

percolation of water, the result being a locally high water 

table and the development of Ultisols exhibiting attenuated 

profiles, mottled clay-rich zones, and horizons having

uncommon characteristics and either diffuse or very abrupt 

boundaries. Spodic horizons commonly are present in the 

sandy epipedon above the clay lenses or beds (Markewich 

and others, 1987a).

Pyrite. The effect of parent material composition on 

soil chemistry is readily apparent in the aluminum saturation of the soils developed in Holocene-age alluvium on the 

terraces of Uphapee Creek in east-central Alabama 

(Markewich and others, 1988). This saturation is apparently 

a direct result of "natural" acidification caused by the 

release of SO4= by the oxidation of pyrite, the formation of 

sulfuric acid, and the mobilization of aluminum from parent 

minerals. Flood water, shallow subsurface water, and rain 

water react with the pyritiferous and lignitic Tuscaloosa 

Formation (Cretaceous) exposed in the stream channel and 

along the valley walls (Markewich and others, 1988) to 

produce low pH solutions that increase the solubility of

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D15
10R

2.5YR

in

~ 5YR

Z 

O

Iy

55 7.5YR

10YR

 8

SAMPLING AREA

A Delmarva Peninsula 

B Rappahannock Valley 

C Cape Fear Valley, NC 

F Augusta, GA 

G Pine Mountain, GA

H Uphapee Creek, AL

____I_______

EXPLANATION

SYMBOL DATA SOURCE

O Markewich and others (1987)

 Markewich and others (1987)

 H.W. Markewich and others (unpublished data, 1980)

O Pavich and others (1981)

A H.W. Markewich and others (unpublished data, 1984)

A Markewich and others (1988)

103 10" 105 10s 107

AGE OF MORPHOSTRATIGRAPHIC UNIT, IN YEARS

Figure 7. Rubification versus age of unit. Rubification is defined by the Munsell hue of the Bt horizon or by the reddest 

hue of the B horizon. Data for sampling areas A through C and F through H are given in the appendix.

aluminum. The unique chemistry of the Uphapee soils results in anomalously high (Fe2O3 +Al2O3)/SiO2 ratios 

(fig. 8).

Feldspar. Weathering of feldspar is generally considered to be the dominant process by which kaolinite and 

gibbsite are formed in the zone of subaerial alteration. 

Following the work of Jackson (1965), many studies have 

dealt with the generation and evolution of clays and 

oxyhydroxides as products of pedogenic processes (Kittrick, 1986; Torrent and others, 1980). Plagioclase feldspar 

alteration is significant because of rapid dissolution kinetics 

relative to other aluminosilicates (for example, muscovite 

and potassium feldspar) and quartz. Silica release to solution has been studied by Holdren and Berner (1979) and 

White and Claassen (1979). In addition to reaction kinetics, 

drainage conditions appear to be a dominant factor determining the removal of dissolved silica. Silica removal is 

necessary for producing amorphous aluminum hydroxide or 

gibbsite (Kittrick, 1969).

Gibbsite is one of the three most common minerals 

found in clay-sized (<2 (Jim) fractions of weathered soils in 

the Southeastern United States; the other two are kaolinite

and hydroxyinterlayered vermiculite. Some published data 

are available on the stability relations of these minerals. 

Glenn and Nash (1964) have discussed the weathering 

relations between gibbsite, kaolinite, chlorite, and expansible silicate clays in the Mississippi Coastal Plain. Weaver 

(1975) has documented the presence of quartz coexisting 

with gibbsite in Brazilian soils. Karathanasis and others 

(1983) have provided an excellent summary of the problem 

of the stability relations of quartz,hydroxyinterlayered vermiculite, and gibbsite.

The presence of labile aluminosilicate minerals and 

drainage conditions both appear to be important controls on 

the formation of gibbsite. Despite evidence that gibbsite can 

form in less than 1 ka (Loughnan, 1969) in a well-drained 

environment, it has been used as an indicator of age and of 

climatic change for a number of Coastal Plain units (Clarke, 

1971; Owens and Minard, 1979; Owens and others, 1983; 

Soller, 1988). Investigations of gibbsite formation indicate 

that it may be formed directly and rapidly by weathering of 

feldspar in tropical, subtropical, and temperate latitudes 

(Watson, 1962; Bakker, 1967; Green and Eden, 1971; 

Lodding, 1972). Data from these studies suggest that

D16 Pedologic Studies in the Eastern United States
£ 35

SAMPLING AREA

A Delmarva Peninsula

B Rappahannock Valley

F Augusta, GA

G Pine Mountain, GA

H Uphapee Creek, AL

| * Indicate minima

EXPLANATION

SYMBOL DATA SOURCE

O Markewich and others (1987)

 Markewich and others (1987)

D Pavich and others (1981)

A H.W. Markewich and others (unpublished data, 1984)

^ Markewich and others (1988)

103 10" 106 106

AGE OF MORPHOSTRATIGRAPHIC UNIT, IN YEARS

107

Figure 8. Percentage of (Fe2O3 +AI2O3)/SiO2 versus age of unit. This ratio is determined from the major-element 

chemistry of the Bt horizons or of the most clay-rich part of the B horizon. Data for sampling areas A, B, and F through 

H are given in the appendix.

gibbsite formation in soils is specifically related to the 

mineralogy of the parent material and to local drainage 

conditions and becomes relatively less abundant in soils as 

weathering proceeds and clay phases are produced.

Heavy minerals. Owens and others (1983) and Soller (1988) have published the only available data on using 

heavy minerals to estimate relative ages of deposits in the 

Coastal Plain. Both used heavy mineral data in conjunction 

with the clay mineralogy of deposits to determine if the 

weathering profiles developed on units were adjusted to the 

ages of those units. The conclusion of both papers was that 

heavy mineral data could be used to establish relative ages 

if care were taken to compare deposits of similar provenance and if other mineralogical data were available. 

Sudom and Arnaud (1971) provided a general discussion of 

the use of quartz, zirconium, and titanium as indices in 

pedological studies. The reader is referred to that paper and 

to papers by Owens and others (1983) and Seller (1988) for 

a more complete review of the method and its reliability.

Geomorphic Position

Edge effect. Variations in weathering and pedogenic development dependent on geomorphic position were 

discussed by Daniels and Gamble (1967). To emphasize the 

importance of the "edge effect" in pedogenic development 

on alluvial and marine terraces, they presented data from 

pedons developed in different positions on the same geomorphic surface. Pedons developed near an erosional 

"edge," or on an original edge slope of a constructional 

landform, are thicker than pedons developed near the center 

of the terrace back-barrier flat or on the broad, flat barrier 

ridge; pedons situated on or near such an edge are also 

oxidized to greater depths. Colman (1983) showed the 

relation of terrace steps and risers to colluvial sediments 

generated during progressive changes in the morphology of 

terraces along the Rappahannock River in southeastern 

Virginia. The older the surface, the more dissected and 

modified the original surface and the greater the possibility 

of composite surficial units. For example, pedons on the

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D17
inner edge of a terrace are commonly developed on parent 

material that is a combination of colluvium from the next 

higher terrace and the subjacent alluvial or marine sediments. The soils developed on these deposits are not 

representative of the soils developed on the terrace itself.

Markewich and others (1986) used the edge effect 

hypothesis to explain the differences between the sola 

thicknesses and chemical properties of the soils analyzed in 

their profiles and those described by Thorn (1967a) from the 

same morphostratigraphic units in the Coastal Plain of 

northeastern South Carolina. Thorn described pedons associated with the edges of marine barriers, whereas 

Markewich and others described pedons from the broad, flat 

upper surfaces of the same barriers. Results from the two 

studies are not directly comparable, but detailed micromorphological analyses and clay mineralogical analyses 

resulted in the same relative age distribution for both 

studies. (Isotopic age determinations were available to 

Markewich and others, who did their fieldwork in the early 

1980's, but not to Thorn, who published in 1967.)

Geomorphic position is also important in soil chemistry. Well-drained profiles are necessary to adequately 

compare (Fe2O3 +Al2O3 )/SiO2 data for relative age determinations. Soils over shallow water tables in the Coastal 

Plain contain less total iron and less iron extractable by 

oxalate, dithionite, and HC1 than do soils above deep water 

tables. Therefore, soils nearer drainages are considered to 

experience oxidizing conditions almost continuously and to 

have lost relatively little iron. By comparison, soils nearer 

the centers of interstream divides experience periodic saturation and reducing conditions that cause removal of soluble 

ferrous iron (Daniels and others, 1975a).

Closed depressions. As mentioned previously, 

closed depression soils, such as those developed in Carolina 

bays, commonly have been attenuated by high water tables 

and have spodic horizons (humates) developed near the base 

of the solum or in the weathered parent material. Parent 

material beneath these organic soils is commonly so extensively leached of iron that all red-yellow color has been 

removed. Few data are available on the chemistry of spodic 

horizons (humates) or on the conditions necessary for their 

formation in subtropical and tropical environments. 

Schnitzer (1977) has determined the composition of some 

humic substances in spodic horizons, and Leenheer (1980) 

has discussed the conditions necessary for the existence of 

spodic horizons in the alluvial terrace soils of the Amazon 

Basin, as DeConinck (1980) did for the Spodosols in 

general.

Spodic horizons in the Coastal Plain of the United 

States have been studied by Malcolm (1964), Swanson and 

Palacas (1965), Thorn (1967b), Holzhey and others (1975), 

Daniels and others (1975b, 1976), and Markewich and 

others (1986). However, none of these studies has looked in 

detail at the processes involved in the development of 

spodic horizons (humates) or at the length of time necessary

800

700

600

CO 

cc

LLJ

LU

I 500

to 400

to

LU

y

X 300

O

CO 200

100

10 20 30 40 

PERCENTAGE OF (Fe2 03 + AI 2 03 )/Si02

50

Figure 9A. Thickness of solum versus maximum percentage 

of (Fe2O3 + AI2O3 )/SiO2 for several 10-ka to 10-Ma units. 

Thickness of solum and major-element ratio are explained in 

figures 4 and 8, respectively. Open circles, Delmarva Peninsula (sampling area A) (Markewich and others, 1987a); solid 

circles, Rappahannock Valley (sampling area B) (Markewich 

and others, 1987a); open block, Augusta, Ga. (sampling area 

F) (Pavich and others, 1981). Arrows indicate minima. Data 

for sampling areas A, B, and F and ages of specific sites are 

given in the appendix.

for the formation of a spodic horizon. The chemical 

signatures of spodic horizons are different from those of the 

adjacent mineral horizons. Generally, they are high in 

base-soluble organic material (humic acids) and insoluble 

organics (humin). In exceptional cases, they are enriched in 

metals such as Al+3 and Fe+3 , complexed with organics. 

Because of the unusual chemistry associated with spodic 

horizons and because of the attenuated weathering and soil 

profiles associated with soils affected by high water tables, 

we do not recommend spodic soils for chronosequence 

studies or other comparative studies. Data from soils and 

weathered parent material associated with these depressions 

have not yet been shown to be useful in age estimations or 

comparisons.

D18 Pedologic Studies in the Eastern United States
50

40

30 h

LU 

O

cc 

a! 20

10 -

SAMPLING AREA

A Delmarva Peninsula

B Rappahannock Valley

F Augusta, GA

G Pine Mountain, GA

H Uphapee Creek, AL

EXPLANATION 

SYMBOL DATA SOURCE

O Markewich and others (1987) 

 Markewich and others (1987) 

Pavich and others (1981)

H.W. Markewich and others (unpublished data, 1984) 

Markewich and others (1988)

Q

A

10 20 50 100 200 

CLAY MASS, IN GRAMS PER SQUARE CENTIMETER

500

Figure 9B. Clay mass versus maximum percentage of (Fe2O3 +AI2O3 )/SiO2 for several 5-ka to 10-Ma units. 

Log scale. Clay mass and major-element ratio are explained in figures 6 and 8, respectively. Data for 

sampling areas A, B, and F through H and ages of specific sites are given in the appendix.

Climate

Latitudinal differences. Only preliminary data are 

available on the differences in the degree and type of 

weathering and soil development in the Middle Atlantic 

Coastal Plain versus those in the Coastal Plain of the 

Southeastern United States. Figure 3 shows a systematic 

difference in the depth of oxidation of sediments in the 

Charleston area of South Carolina (area E, fig. IB) (McCartan and others, 1984) when they are compared with units of 

similar age in the Coastal Plain of Virginia and North 

Carolina (areas A, B, and C, fig. IB). Unpublished depth of

oxidation data from Pliocene- and Pleistocene-age sediments in Georgia (H.W. Markewich, unpublished data, 

1984-86) show depths similar to or greater than those 

reported from the Charleston area. Although the density of 

data is not adequate to construct a line or transition zone 

between the more intense weathering of the South Carolina 

and Georgia Coastal Plain and the less intense weathering of 

the Virginia Coastal Plain, weathering appears to be more 

intense in the Piedmont and the Coastal Plain of South 

Carolina, Georgia, and eastern Alabama. The Coastal Plain 

of Georgia has mean annual temperatures of 15 °C to 16 °C

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D19
COLUMN 1 COLUMN 2 CO

ETWl

5

c 

=>

I

<y>

sr

Oyster: Site A-3

DEPTH (cm) HORIZON

0-27 Ap

27-50 B21t

50-70 B22t

70-117 B23t

117-132 ||B24t

132-147 IIB251

147-175 IIB3

175-215 IIC

Persimmon Point: Site A-5

DEPTH (cm) HORIZON 

0-24 Ap

B21t 

B22t

B23t

o <

6

5

< » 

in

+ 3

CM

1

n

-

-

A 

~ 

A

1 1 1 

200 400 600 

PERCENT

IN 

VI K G HQ KQ

23-m terrace: Site B-2

DEPTH (cm) HORIZON

0-23 Ap 

23-30 B1

148-162 B26t

45-m terrace: Site B 3

DEPTH (cm) HORIZON 

0-12 Ap

Figure 10A. Clay mineral data for Pleistocene-age soils developed on 60- to 

125-ka and 200-ka marine terraces on the Delmarva Peninsula and for 200-ka 

to >1 -Ma fluvial marine terraces of the Rappahannock River in Virginia. X-ray 

diffraction patterns in columns 1 and 2 are from selected soil horizons on the 

Delmarva Peninsula (sites A-3 and A-5) and in the Rappahannock Valley (sites 

B-2 and B-3). Traces illustrated are of oriented, untreated clay. Peak spacings 

above the peaks are in angstroms. Depths of horizons are in centimeters.

213-250 B28t

E

12-28

28-43

60-84

84-112

112-146

A2

B21t

B23t

B24t

B25t

0

!<

uj m

I oq

^ +

UJ <

"-CM

u. <?

0 «-

3 ** 

in

+ 2

<t

tN

^ 1

0

£ 0 

 23

~ o 45

_

-

~° 0

* o» o. 

i i i 

0 1000 2000 300

PERCENTAGE C

146-175

175-213

B26t

B27t

IN CENTI

Mineral identifications at the bottom of each se

V, hydroxyinterlayered vermiculite; I, illite; K

halloysite; Q, quartz. Column 3 shows the ra

A+4.95 A/7.2 A+4.5 A peaks plotted against hori

of clay per horizon for sites A-3 and A-5 (upper 

plot). Data for percentage of clay per horizon a
DEPTH (m) HORIZON

0-.33 A1

.33-1.12 A21

1.12-1.57 A22

1.57-1.96 B1

1.96-2.22 B21t

2.22-2.71 B22t

2.71-3.23 B23t

3.23-3.56 B24t

3.56-4.00 B25t

4.00-4.67 B26t

4.67-4.92 B31

4.92-5.58 B32

5.58-6.36 C1

6.36-6.90 C2

6.90-7.38 IIB21tb

7.38-7.97 IIB22tb

7.97-8.28 IIBSb

8.28-8.60 IIIB21tb

8.60-9.40 IIIB31b

9.40-10.34 IIIB32b

10.34-10.70 IIIB33b

V K K Q

Figure 10B. Clay mineral data for a Pliocene-age soil 

from Augusta, Ga. X-ray diffraction data (Pavich and 

others, 1981) are taken from a topographically high 

remnant of Pliocene colluvium overlying earlier 

Tertiary sediment from the inner Coastal Plain near 

the Savannah River (site F-3, appendix). Traces 

illustrated are of oriented, untreated clay. Peak 

spacings above the peaks are in angstroms. Depths 

of horizons are in meters. Mineral identifications at 

the bottom of each set of patterns are as follows: V, 

hydroxyinterlayered vermiculite; K, kaolinite; Q, 

quartz.

and mean annual precipitation of around 1,200 mm. It is a 

subprovince of the area outlined on figure IA as having 

low-activity clay (LAC) soils, 6 which make up as much as

3.54

DEPTH (cm) HORIZON 

47-66 B21t(Bt1)

66-89 B22t (Bt2)

123-161 B23t(Bt3)

190-215 IIC (C2)

V M K M,Q

6Cation exchange capacity is less than 16 meq/100 g clay (determined by NH4OAc at pH 7) or an effective value of less than 12 meq/100 

g clay (determined as the sum of exchangeable bases plus KC1 extractable 

Al).

Figure 10C Clay mineral data for a Holocene-age soil 

developed in the Alabama Coastal Plain. X-ray diffraction 

patterns of magnesium-saturated and glycol-splvated 

(magnesium-saturated) clay (dotted line) are from site H-3 

(appendix). Peak spacings above the peaks are in angstroms. Depths of horizons are in centimeters. Mineral 

identifications at the bottom of each set of patterns are as 

follows: V, vermiculite; M, muscovite; K, kaolinite; Q, 

quartz.

65 percent of the region's soils. According to L.P. 

Wilding (written communication, 1986):

Genetically, the predominance of LAC is important because it 

reflects specific parent materials from which the soils formed 

or an advanced state of weathering.

The recognition and eventual delineation of the subprovince of intense weathering within the LAC soil province are essential for accurate comparison of soil and 

weathering profile data. As Nichols and others (1985) 

stated, the greatest concentration (of LAC soils) occurs 

above 29 m altitude. In the Carolinas, this altitude is 

approximately coincident with the landward limit of the 

800-ka to 1-Ma marine terraces (Dubar and others, 1980; 

McCartan and others, 1984; Owens, 1989; Seller, 1988).

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D21
Data from McCartan and others (1984) and fieldwork done 

by D.C. Prowell (unpublished data, 1981-86) and H.W. 

Markewich (unpublished data, 1981-84) suggest that these 

LAC soils are thicker and more intensely weathered than 

non-LAC soils and that they occur on morphostratigraphic 

units as young as 200 ka in the Coastal Plain of South 

Carolina and southeastern Georgia. (Although most of the 

included data are from the tropics, we refer the reader to a 

Soil Science Society of America (1986) report.)

Although they are not discussed in detail in this 

paper, weathering profiles developed on sediments no 

younger than early Pliocene in age in the southeastern 

Atlantic and eastern Gulf Coast sections of the Coastal Plain 

of the Eastern United States are commonly weathered to 

depths of greater than 15m and have 1- to 5-m-thick sandy 

surface horizons and sola thicknesses of 7 to 10 m (H.W. 

Markewich, unpublished data, 1980-85). These profiles are 

associated with constructional landforms such as marine 

barriers and alluvial fans or with erosional surfaces on 

sandy sediments that have been stable for several million 

years. The origin of these sandy surficial horizons in 

Atlantic Coastal Plain soils was studied by Gamble (1965) 

and Gamble and others (1970). Recently, Mac Vicar and 

others (1985) studied the origin of similar sandy surficial 

layers in soil profiles developed on the coast of Natal, West 

Africa. Studies in both the United States and West Africa 

concluded that there are no significant differences between 

the composition, grain size, or origin of the sand that forms 

the surficial horizons and those of the sand in the underlying 

argillic horizons and weathered parent material. The uniformity of the sand and the transitional contact between 

surficial and subjacent horizons suggest that the surficial 

horizons result from eluviation and chemical dissolution 

and are not the result of more recent eolian or fluvial 

sedimentation. The fact that comparable profiles do not 

constitute a significant component of Coastal Plain soils 

north of southeastern Virginia can be interpreted as another 

indicator of more intense weathering and (or) greater age in 

the Coastal Plain of the Southeastern States.

Precipitation and prevailing winds. Large dune 

fields and expansive sand sheets suggest that, at least 

through the late Quaternary and possibly from the Pliocene 

into the middle Holocene, the wet-temperate to subtropical 

climatic regimes of the Middle Atlantic and Southeastern 

States were interrupted by periods of decreased runoff and 

high winds (Veatch and Stephenson, 1911; Pickering and 

Jones, 1974; Thames, 1982; Owens and Denny, 1979). 

Detailed mapping of these dune fields and sand sheets in 

Georgia (H.W. Markewich, unpublished data, 1986) and on 

the Delmarva Peninsula of Delaware and Maryland (Owens 

and Denny, 1979) suggests that there have been several 

periods of dune development and that individual dune fields 

and adjacent sand sheets can extend several miles from their 

source areas. Thus, some of the sand incorporated in the 

near-surface horizons of soils developed in Coastal Plain

sediments may be eolian in origin, and an overprint of 

characteristics common to more arid climates may be 

incorporated into the soil and weathering profiles of the 

middle Atlantic and southeastern Coastal Plain.

Soil Chemistry and Mineralogy

To date, the most reliable chemical parameter to use 

as an indicator of soil age is (Fe2O3 +Al2O3 )/SiO2 . In 

general, both dithionite-extractable and iron and total iron 

increase with soil age. Other studies have shown an increase 

of hematite and redness with soil age and an association 

between redness and hematite in the fine-earth fraction 

(Davey and others, 1975; Torrent and others, 1980; 

Arduino and others, 1986). Although our data show a trend 

of increasing redness with soil age, we do not yet have 

sufficient data to substantiate an increase in hematite 

content correlated with an increase in redness or soil age. 

X-ray diffraction data do not show significant amounts of 

hematite. Goethite is the dominant iron oxyhydroxide in the 

clay-sized fraction of the southeastern Coastal Plain.

Clay mineral data may also help in differentiating 

soils of different ages if the soil parent materials are of the 

same provenance. Figure 10A shows a plot of clay peak 

ratios for 60- to 125-ka and 200-ka marine terraces on the 

Delmarva Peninsula and for 200-ka to >l-Ma fluvial 

marine terraces of the Rappahannock River in Virginia 

(Markewich and others, 1987a). Figure 105 shows a plot 

from a Georgia Coastal Plain soil considered to be no 

younger than early Pliocene in age (Pavich and others, 

1981). With increasing age, the percentage of kaolinite 

increases, whereas the percentages of vermiculite and 

gibbsite decrease. Since provenance and climate vary significantly from region to region, clay minerals are probably 

of limited use in making age correlations across major 

latitudinal, parent material, or topographic boundaries. For 

example, Holocene terraces from Alabama (fig. 10C) show 

very high percentages of kaolinite in the parent material and 

soil clay fractions, a reflection of the different provenance 

for the soil parent material in Delmarva and Alabama.

CONCLUSIONS

It is possible to estimate order-of-magnitude ages (10 

ka versus 100 ka versus 1 Ma) of morphostratigraphic units 

in the Coastal Plain of the Eastern United States on the basis 

of their degrees of weathering and soil development.

Parent material, relief (topography and geomorphic 

position), and time are the most important controls on 

weathering and soil development within a given climatic 

regime.

The most reliable indicators of soil age are the 

thickness of the solum, the thickness of the argillic horizon, 

rubification, clay mass, and (Fe2O3 +Al2O3 )/SiO2 . This

D22 Pedologic Studies in the Eastern United States
oxide ratio is particularly useful in differentiating between 

soils that range in age from about 200 to 800 ka, although 

data are not sufficient to determine which parameters are 

reliable determinations of soil age within this age range.

Depth of oxidation is a reliable indicator of soil age if 

only the best-drained sites are compared; commonly, these 

sites are located near but not on the eroded boundaries or 

primary sloping parts of the landform (that is, the edge of an 

alluvial terrace nearest the present channel or the side slope 

of a marine barrier).

There is an evolution of Coastal Plain soils from 

Inceptisols to Alfisols to Ultisols (Hapludults to 

Paleudults). Inceptisols appear to be as young as Holocene 

and no older than a few tens of thousands of years. 

Hapludults are associated with a wide variety of ages from 

a few tens of thousands of years to several hundred 

thousand years. Paleudults are associated with morphostratigraphic units that are older than 800 ka. (Data are not 

sufficient to differentiate soils in the 200- to 800-ka range.)

Most soils that are older than 800 ka and that have a 

parent material greater than 80 percent quartz sand have 

bisequal profiles and sola thicknesses greater than 3 m.

On similar parent materials of the same age under 

different climates in Virginia and Georgia, there are differences in the depths and types of weathering and development of soils. These differences apparently are directly 

related to climate but are manifested as differences in clay 

mineralogy and the mineralogy of the clay-sized fraction, in 

the depth of oxidation, in the pattern of iron segregation, in 

horizonization, and in the thickness of the solum. Identification of these differences is essential in comparing soil and 

weathering profiles in the middle Atlantic and southeastern 

sections of the Atlantic Coastal Plain.

REFERENCES CITED

Arduino, E., Barberis, E., Marsan, F.A., Zanini, E., and Franchini, M., 1986, Iron oxides and clay minerals within profiles 

as indicators of soil age in northern Italy: Geoderma, v. 37, 

p. 45-55.

Bakker. J.P., 1967, Weathering of granites in different climates, 

particularly in Europe, in Macar, P., ed., L'evolution des 

versants: Liege, Belgium, Universite de Liege et Academic 

Royale de Belgique, p. 51-68.

Birkeland, P.W., Burke, R.M.. and Shroba, R.R., 1987, 

Holocene and alpine soils in gneissic cirque deposits, Colorado Front Range: U.S. Geological Survey Bulletin 1590-E, 

21 p.

Blackwelder, B.W., and Ward, L.W., 1979, Stratigraphic revision of the Pliocene deposits of North and South Carolina: 

South Carolina Division of Geology Geologic Notes, v. 23, 

no. 1, p. 33^9.

Bockheim, J.G., 1980, Solution and use of chronofunctions in 

studying soil development: Geoderma, v. 24, p. 71-85.

Carter, R.F., and Stiles, H.R., 1983, Average annual rainfall and 

runoff in Georgia, 1941-70 Hydrologic Atlas 9: Atlanta, 

Georgia Department of Natural Resources, 1 pi.

Clarke, O.M., Jr., 1971, Gibbsite in Coastal Plain soils, southeastern United States: Southeastern Geology, v. 13, p. 77-90.

Colman, S.M., 1983, Progressive changes in the morphology of 

fluvial terraces and scarps along the Rappahannock River, 

Virginia: Earth Surface Processes and Landforms, v. 8, p. 

201-212.

Cronin, T.M., and Hazel, J.E., 1980, Ostracode biostratigraphy 

of Pliocene and Pleistocene deposits of the Cape Fear Arch 

region, North and South Carolina: U.S. Geological Survey 

Professional Paper 1125-B, 25 p.

Cronin, T.M., Bybell, L.M., Poore, R.Z., Blackwelder, B.W., 

Liddicoat, J.C., and Hazel, J.E., 1984, Age and correlation 

of emerged Pliocene and Pleistocene deposits, U.S. Atlantic 

Coastal Plain: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 47, p. 21-51.

Daniels, R.B., and Gamble, E.E., 1967, The edge effect in some 

Ultisols in the North Carolina Coastal Plain: Geoderma, v. 1, 

p. 117-124.

Daniels, R.B., Gamble, E.E., and Wheeler, W.H., 1971, Stability of Coastal Plain surfaces: Southeastern Geology, v. 13, p. 

61-75.

Daniels, R.B., Gamble, E.E., Buol, S.W., and Bailey, H.H., 

1975a, Free iron sources in an Aquult-Udult sequence from 

North Carolina: Soil Science Society of America Proceedings, v. 39. p. 335-340.

Daniels, R.B., Gamble, E.E., and Holzhey, C.S., 1975b, Thick 

Bh horizons in the North Carolina Coastal Plain, I, Morphology and relation to texture and soil ground water: Soil 

Science Society of America Proceedings, v. 39, p. 

1177-1181.

 1976, Humate, Bh soil horizons, in wet sands of the North 

Carolina Coastal Plain: Southeastern Geology, v. 19, p. 

61-81.

Daniels, R.B., Gamble, E.E., and Wheeler, W.H., 1978, Age of 

soil landscapes in the Coastal Plain of North Carolina: Soil 

Science Society of America Journal, v. 42, no. 1, p. 98-105.

Davey, E.G., Russell, J.D., and Wilson, M.J., 1975, Iron oxide 

and clay minerals and their relation to colours of red and 

yellow podzolic soils near Sydney, Australia: Geoderma, v. 

14, p. 125-138.

DeConinck, F., 1980, Major mechanisms in the formation of 

spodic horizons: Geoderma, v. 24, p. 101-124.

DuBar, J.R., DuBar, S.S., Ward, L.W., and Blackwelder, B.W., 

1980, Cenozoic biostratigraphy of the Carolina outer Coastal 

Plain, with contributions by W.H. Abbott and P.P. Huddlestun: Geological Society of America Guidebook, Field Trip 

9, 236 p.

Foss, J.E., Fanning, D.S., Miller, P.P., and Wagner, D.P., 1978, 

Loess deposits of the eastern shore of Maryland: Soil Science 

Society of America Journal, v. 42, p. 329-344.

Gamble, E.E., 1965, Origin and morphogenetic relations of sandy 

surficial horizons of upper Coastal Plain soils of North 

Carolina: Raleigh, North Carolina State University, unpublished Ph.D. dissertation, 254 p.

Gamble, E.E., Daniels, R.B., and McCracken, R.J., 1970, A2 

horizons of Coastal Plain soils, pedogenic or geologic origin: 

Southeastern Geology, v. 11, p. 137-152.

Glenn, R.C., and Nash, V.E., 1964, Weathering relationships 

between gibbsite, kaolinite, chlorite, and expansible layer 

silicates in selected soils from the lower Mississippi Coastal 

Plain, in Clays and clay minerals, proceedings from the 12th 

National Conference on Clays and Clay Minerals: Pergamon 

Monograph 19, Earth Science Series, p. 529-548.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D23
Green, C.P., and Eden, M.J., 1971, Gibbsite in the weathered 

Dartmoor Granite: Geoderma, v. 6, p. 315-317.

Hack, J.T., 1982, Physiographic divisions and differential uplift 

in the Piedmont and Blue Ridge: U.S. Geological Survey 

Professional Paper 1265, 49 p., 29 figs., 2 tables.

Harden, J.W., 1982, A quantitative index of soil development 

from field descriptions: Examples from a chronosequence in 

central California: Geoderma, v. 28, p. 1-28.

 1987, Soils developed in granitic alluvium near Merced, 

California: U.S. Geological Survey Bulletin 1590-A, 65 p.

Harden, J.W., Sarna-Wojcicki, A.M., and Dembroff, G.R., 

1986, Soils developed on coastal and fluvial terraces near 

Ventura, California: U.S. Geological Survey Bulletin 1590- 

B, 34 p.

Hazel, J.E., 1983, Age and correlation of the Yorktown (Pliocene) 

and Croatoan (Pliocene and Pleistocene) formations at the 

Lee Creek, North Carolina, open pit mine, in Ray, C.E., ed., 

Geology and paleontology of the Lee Creek Mine, North 

Carolina, I: Smithsonian Contributions to Paleobiology, no. 

53, p. 81-199.

Holdren, G.R., and Berner, R.A., 1979, Mechanism of feldspar 

weathering, I, Experimental studies: Geochimica et Cosmochimica Acta, v. 43, p. 1161-1171.

Holzhey, C.S., Daniels, R.B., and Gamble, E.E., 1975, Thick Bh 

horizons in the North Carolina Coastal Plain, II, Physical and 

chemical properties and rates of organic additions from 

surface sources: Soil Science Society of America Proceedings, v. 39, p. 1182-1187.

Jackson, M.L., 1965, Clay transformations in soil genesis during 

the Quaternary: Soil Science, v. 79, no. 1, p. 15-22.

Jenny, H., 1941, Factors of soil formation: New York, McGrawHill, 281 p.

Karathanasis, A.D., Adams, P., and Hajek, B.F., 1983, Stability 

relationships in kaolinite, gibbsite, and Al-hydroxyinterlayered vermiculite soil systems: Soil Science Society of 

America Journal, v. 47, p. 1247-1251.

Kittrick, J.A., 1986, ed., Soil mineral weathering: New York, 

Van Nostrand Reinhold, 271 p.

 1969, Soil minerals in the A12O3 SiO2 -H2O system and 

a theory of their formation: Clays and Clay Minerals, v. 17, 

p. 157-167.

Leenheer, J.A., 1980, Origin and nature of humic substances in 

the waters of the Amazon River basin: Acta Amazonica, v. 

10, no. 3, p. 513-526.

Lodding, W., 1972, Conditions for direct formation of gibbsite 

from K-feldspar Discussion: American Mineralogist, v. 57, 

p. 292-294.

Loughnan, F.C., 1969, Chemical weathering of the silicate 

minerals: New York, American Elsevier, 154 p.

MacVicar, C.N., Hutson, J.L., and Fitzpatrick, R.W., 1985, Soil 

formation in the coast aeolianites and sands of Natal: Journal 

of Soil Science, v. 36, p. 373-387.

Malcolm, R.L., 1964, Mobile soil organic matter and its interpretations with clay minerals and sesquioxides: Raleigh, North 

Carolina State University, unpublished Ph.D. dissertation, 

148 p.

Markewich, H.W., 1985, Geomorphic evidence for PliocenePleistocene uplift in the area of the Cape Fear Arch, North 

Carolina, in Morisawa, M., and Hack, J.T., eds., Tectonic 

geomorphology: Boston, Alien and Unwin, p. 279-298.

Markewich, H.W., and Christopher, R.A., 1982, Pleistocene(?) 

and Holocene fluvial history of Uphapee Creek, Macon 

County, Alabama: U.S. Geological Survey Bulletin 1522, 

16 p.

Markewich, H.W., Pavich, M.J., Mausbach, M.J., Stuckey, 

B.N., Johnson, R.G., and Gonzalez, V.M., 1986, Soil

development and its relation to the ages of morphostratigraphic units in Horry County, South Carolina: U.S. Geological Survey Bulletin 1589-B, 61 p.

Markewich, H.W., Pavich, M.J., Mausbach, M.J., Hall, R.L., 

Johnson, R.G., and Hearn, P.P., 1987a, Age relationship of 

soils to geology on the Coastal Plain of Maryland and 

Virginia: U.S. Geological Survey Bulletin 1589-A, 34 p.

Markewich, H.W., Lynn, W., Pavich, M.J., and Thomas, G., 

1987b, Charcteristics of soils developed in the Pine Mountain 

area of the Piedmont province of Georgia (Soil Science 

Society of America field trip, Dec. 1987): U.S. Geological 

Survey Open-File Report 87-645, 95 p.

Markewich, H.W., Lynn, W.L., Pavich, M.J., Johnson, 

R.G.,and Meetz, J., 1988, Analyses of four Inceptisols of 

Holocene age, east-central Alabama: U.S. Geological Survey 

Bulletin 1589-C, 29 p.

McCartan, L., Owens, J.P., Blackwelder, B.W., Szabo, B.J., 

Belknap, D.F., Kriausakul, N., Mitterer, R.M., and Wehmiller, J.F., 1982, Comparison of amino acid racemization 

geochronometry with lithostratigraphy, uranium series coral 

dating, and magnetostratigraphy in the Atlantic Coastal Plain 

of the southeastern United States: Quaternary Research, 

v. 18, p. 337-359.

McCartan, L., Lemon, E.M., Jr., and Weems, R.E., 1984, 

Geologic map of the area between Charleston and Orangeburg, South Carolina: U.S. Geological Survey Miscellaneous 

Investigations Map 1-1472, scale 1:250,000.

McFadden, L.D., and Weldon, R.J., II, 1987, Rates and processes of soil development in Quaternary terraces of Cajon 

Pass, California: Geological Society of America Bulletin, 

v. 98, p. 280-293.

Miller, B.J., in press, Pedology, in Autin, W.J., ed., Quaternary 

geology of the lower Mississippi Valley, in Morrison, R.B., 

ed.. Quaternary non-glacial geology of the conterminous 

United States: Boulder, Colo., Geological Society of America, Decade of North American Geology, v. K-2, ch. 13, 

p. 42-56.

Miller, F.P., 1974, Soil temperatures in Maryland: University of 

Maryland Department of Agronomy Soil Survey Series 6, 

14 p.

Mixon, R.B., 1985, Stratigraphic and geomorphic framework of 

uppermost Cenozoic deposits in the southern Delmarva Peninsula, Virginia and Maryland: U.S. Geological Survey 

Professional Paper 1067-G, 53 p.

Mixon, R.B., Szabo, B.J., and Owens, J.P., 1982, Evaluation of 

uranium-series dating of mollusks and corals and age of 

Pleistocene deposits, Chesapeake Bay area, Virginia and 

Maryland: U.S. Geological Survey Professional Paper 

1067-E, 18 p.

Mixon, R.B., Berquist, C.R., Jr., Newell, W.L., and Johnson, 

G.H., 1989, Geologic map of the Coastal Plain and adjacent 

parts of the Piedmont, Virginia, with generalized geologic 

cross sections by R.B. Mixon, D.S. Powars, J.S. Schindler, 

and E.K. Rader: U.S. Geological Survey Miscellaneous 

Investigations Map 1-2033, 2 pis., scale 1:250,000.

Muhs, D.R., 1982, A soil chronosequence on Quaternary marine 

terraces, San Clemente Island, California: Geoderma, v. 28, 

p. 257-283.

Nahon, D., and Trompette, R., 1982, Origin of siltstones: Glacial 

grinding vs. weathering: Sedimentology, v. 29, p. 25-35.

Nichols, J.D., Wilding, L.P., and Pettry, D.E., 1985, Low 

activity clay soils of the United States, in Eswaren, H., ed., 

Properties, classification and management of low activity 

Ultisols and Alfisols: Soil Management Support Services 

Technical Monograph 14, p. 31-36.

D24 Pedologic Studies in the Eastern United States
Nikiforoff, C.C., 1949, Weathering and soil evolution: Soil 

Science, v. 67, p. 219-230.

Owens, J.P., 1989, Geology of Cape Fear area, Florence 2° and 

northern half of Georgetown 2° quadrangles, North and South 

Carolina: U.S. Geological Survey Miscellaneous Field Studies Map MF-1498-A, scale 1:250,000.

Owens, J.P., and Denny, C.S., 1979, Upper Cenozoic deposits of 

the central Delmarva peninsula, Maryland and Delaware: 

U.S. Geological Survey Professional Paper 1067-A, 28 p.

Owens, J.P., and Minard, J.P., 1979, Upper Cenozoic sediments 

of the lower Delaware valley and the northern Delmarva 

Peninsula, New Jersey, Pennsylvania, Delaware, and Maryland: U.S. Geological Survey Professional Paper 1067-D, 

47 p.

Owens, J.P., Hess, M.M., Denny, C.S., and Dwornik, E.J., 

1983, Postdepositional alteration of surface and near-surface 

minerals in selected Coastal Plain formations of the Middle 

Atlantic States: U.S. Geological Survey Professional Paper 

1067-F, 45 p.

Pavich, M.J., Newell, W.L., Mausbach, M.J., and Paulk, H., 

1981, Geomorphology and soils of the inner Coastal Plain 

margin near Augusta, Georgia: A guidebook for the Soil 

Science Society of America Meeting, December 3-5, 1981: 

Madison, Wis., Soil Science Society of America, 61 p.

Pickering, S.M., and Jones, R.C., 1974, Morphology of aeolian 

parabolic sand features along streams in southeast Georgia 

[abs.]: Geological Society of America Abstracts with Programs, v. 6, p. 387-388.

Prowell, D.C., 1988, Cretaceous and Cenozoic tectonism on the 

Atlantic coastal margin, in Grow, J.A., ed., Decade of North 

American Geology Atlantic Continental Margin Volume: 

Boulder, Colo., Geological Society of America, p. 557-564.

Pye, K., 1983, Formation of quartz silt during humid tropical 

weathering of dune sands: Sedimentary Geology, v. 34, 

p. 267-282.

Reheis, M.C., 1987, Soils in granitic alluvium in humid and 

semiarid climates along Rock Creek, Carbon County, Montana: U.S. Geological Survey Bulletin 1590-D, 71 p.

Ruffner, J.A., and Bair, F.E., eds., 1977, The weather almanac, 

2d ed.: Detroit, Mich., Gale Research Company, 728 p.

Schnitzer, M., 1977, Recent findings on the characterization of 

humic substances extracted for soils from widely differing 

climatic zones, in Soil organic matter studies: Vienna, 

Atomic Energy Agency, v. II, p. 117-132.

Soil Management Support Services, 1986, Designations for master 

horizons and layers in soils: Ithaca, N.Y., Cornell University, Department of Agronomy, 16 p.

Soil Science Society of America, 1986, Proceedings of a symposium on low-activity clay (LAC) soils: Soil Management 

Support Services Technical Monograph 14, 131 p.

Soil Survey Staff, 1962, Soil survey manual: Washington, D.C., 

U.S. Department of Agriculture Handbook 18, 503 p.

 1975, Soil taxonomy: Washington, D.C., U.S. Department of Agriculture Handbook 436, 754 p.

Soller, D.R., 1988, Geology and tectonic history of the lower 

Cape Fear River valley, southeastern North Carolina: U.S. 

Geological Survey Professional Paper 1466-A, 60 p.

Sudom, M.D., and Arnaud, R.J., 1971, Use of quartz, zirconium, 

and titanium as indices in pedological studies: Canadian 

Journal of Soil Science, v. 51, p. 385-396.

Swanson, V.E., and Palacas, J.G., 1965, Humate in coastal sands 

of northwest Florida: U.S. Geological Survey Bulletin 

1214-B, 24 p.

Switzer, P.S., Harden, J.W., and Mark, R.K., 1988, A statistical 

method for estimating rates of soil development and ages of 

geologic deposits: A design for soil chronosequence studies: 

Mathematical Geology, v. 20, no. 1, p. 49-61.

Thames, B., 1982, Origin of sand ridges along streams in 

southeastern Georgia: Atlanta, Ga., Emory University, 

unpublished M.Sci. thesis, 113 p.

Thorn, E.G., 1967a, Coastal and fluvial landforms, Horry and 

Marion Counties, South Carolina: Louisiana State University 

Studies, Coastal Studies Series, no. 19, 75 p.

 1967b, Humate in coastal geomorphology: Louisiana State 

University Studies, Coastal Studies Series Bulletin, v. 1, 

p. 15-17.

Torrent, J., 1976, Soil development in a sequence of river terraces 

in northern Spain: Catena, v. 3, p. 137-151.

U.S. Geological Survey, 1970, The national atlas of the United 

States of America: Washington, D.C., 417 p.

Veatch, O., and Stephenson, L.W., 1911, Preliminary report on 

the geology of the Coastal Plain of Georgia: Georgia Geological Survey Bulletin 26, 466 p.

Vita-Finzi, C., and Smalley, I.J., 1970, Origin of quartz silt: 

Comments on a note by P. H. Kuen: Journal of Sedimentary 

Petrology, v. 40, p. 1367-1369.

Watson, J.P., 1962, Formation of gibbsite as a primary weathering product of acid igneous rocks: Nature, v. 196, 

p. 1123-1124.

Weaver, R.M., 1975, Quartz presence in relationship to gibbsite 

stability in some highly weathered soils of Brazil: Clays and 

Clay Minerals, v. 23, p. 431-436.

White, A.F., and Claassen, H.C., 1979, Dissolution kinetics of 

silicate rocks Application to solute modeling: American 

Chemical Society Symposium Series, v. 93, p. 447-473.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D25

APPENDIX 

Field and Laboratory Data Used to Construct Figures 3 through 10

Site A-1. Eastern Neck Island, Delmarva Peninsula (28 ka)

[Data from Markewich and others (1987a)]

Depth

(cm)

0-13 .........

13-31 .......

31^3 .......

43-69 .......

69-92 .......

92+.........

Horizon1

. .... Al

. . . . . A2

. .... B21

. . . . . B22

. . . . . B3

c

Moist color2

10YR5/1

10YR5/1

10YR6/4

10YR5/6

10YR6/4

10YR5/6

Texture3

si

si

sil

si

s

Clay 

(<2 (Jim) 

(percent)

5.8

5.3

4.4

6.0

1.6

10.5

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 si, sandy loam; sil, silty loam; s, sand.

Site A-2. joynes Neck, Delmarva Peninsula (60-125 ka)]

Data from Markewich and others (1987a). , no data]

Depth

(cm)

0-28 ..........

28^5 .........

45-67 .........

67-86 .........

86-106 ........

106-122 .......

122-146 .......

146-188 .......

188-202 .......

202-235

235-245 .......

Horizon1

An

B21t

B22t

B23t

B24t

B25t

Cl

C2

B'h

IIC3

IIC4

Moist color2

10YR4/3

7.5YR4/4

7.5YR4/4

7.5YR5/6

7.5YR6/5

7.5YR5/6

7.5YR5/8

10YR5/6

10YR6/6

10YR5/4

10YR5/4

Bulk density3 

(g/cm3)

1.65

1.62

1.48

1.61

1.72

1.67

1.50

5 1.60

5 1.70

5 1.70

5 1.70

Texture4

fsl

si

1

1

1

si

Is

s

Is

Is

s

Clay

(<2 (Jim) 

(percent)

8.6

15.9

17.1

17.5

16.3

12.1

6.4

2.4

2.0

.4

Fe2O3 +AI2O3

SiO2 

(percent)

8.3

12.9

14.5

14.0

13.7

9.9

5.9

3.3

4.5

4.0

2.3

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4fsl, fine sandy loam; si, sandy loam; 1, loam; Is, loamy sand; s, sand.

Estimated.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D29
Site A-3. Oyster, Delmarva Peninsula (60-125 ka)

[Data from Markewich and others (1987a)]

Depth

(cm)

0-27 ..........

27-50 .........

50-70 .........

70-117........

117-132.......

132-147 .......

147-175 .......

175-215.......

Horizon1

B21t

B22t

B23t

IIB24t

IIB25t

IIB3

IIC

Moist color2

10YR4/3

7.5YR5/6

7.5YR5/6

7.5YR5/6

7.5YR5/8

7.5YR5/8

10YR5/6

10YR8/3

Bulk density3 

(g/cm3 )

1.83

1.79

1 57

1.67

5 1.80

1.81

5 1.80

5 1.80

Texture4

si

1

1

1

si

si

Is

s

Clay

(<2 (Jim) 

(percent)

5.3

17.1

22.1

18.8

7.3

5.2

1.6

.8

Fe2O3 +AI2O3

SiO2 

(percent)

4.9

12.2

18.1

12.4

6.6

7.5

3.5

4.7

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 l/3 bar.

4sl, sandy loam; 1, loam; Is, loamy sand; s, sand.

Estimated.

Site A-4. Nelsonia, Delmarva Peninsula (140-220 ka)

[Data from Markewich and others (1987a)]

Depth

(cm)

0-12 ..........

12-22.........

22^0 .........

40-63 .........

63-79 .........

79-95 .........

95-121 ........

121-130.......

130-150 .......

150-159.......

159-169 .......

Horizon1

An

A12

B21t

B22t

B23t

B31

B32A'2

B'21hir

B'22hir

B'23h

B'24h

Moist color2

10YR4/3

10YR4/3

7 5YR4/4

7.5YR4/4

7.5YR5/6

7.5YR5/6

10YR5/6

10YR5/6

7.5YR4/4

7.5YR4/4

5YR3/2

Bulk density3 

(g/cm3 )

5 1.60

5 1 60

5 1.50

1.53

5 1 50

1.56

5 1 60

1.60

1.55

1.60

1.60

Texture4

fsl

fsl

1

1

si

si

Ifs

Ifs

s

Is

Is

Clay

(<2 (xm) 

(percent)

6.8

8.2

22.9

23.4

13.4

6.4

3.6

3.3

.8

.8

.4

Fe2O3 +AI2O3

SiO2

(percent)

6.1

7.7

16.3

18.7

10.3

4.7

2.5

5.0

3.9

1.9

1.8

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4fsl, fine sandy loam; 1, loam; si, sandy loam; Ifs, loamy fine sand; s, sand; Is, loamy sand.

Estimated.

D30 Pedologic Studies in the Eastern United States
Site A-5. Persimmon Point, Delmarva Peninsula (200 ka)

[Data from Markewich and others (1987a). , no data]

Depth

(cm)

0-24 ..........

24-44 .........

44-65 .........

65-84 .........

84-99 .........

99-122 ........

122-150 .......

150-173 .......

173-200 .......

200-232 .......

Horizon1

. . . . Ap

B21t

B22t

B23t

B24t

IIB25ir

IIB31

IIB32

IIB33

IIC

Moist color2

10YR4/3

7.5YR5/6

7.5YR5/6

7.5YR5/6

7.5YR5/6

2.5YR3/6

2.5YR3/6

7.5YR5/8

7.5YR5/6

2.5YR7/6

Bulk density 3 

(g/cm3 )

1.69

1.69

1.51

5 1.50

1.51

1.87

5 1.80

5 1.80

5 1.80

5 1.80

Texture4

fsl

scl

cr*1

scl

s

s

s

Clay

(<2 (Jim) 

(percent)

8.2

21.7

22.1

17.1

15.1

2.4

1.6

.4

Fe2O3 +AI2O3

SiO2 

(percent)

10.4

16.6

15.5

11.7

9.1

3.2

1.0

13.6

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4fsl, fine sandy loam; scl, sandy clay loam; s, sand.

5Estimated.

Site B-1. Morris Bridge, Rappahannock River Valley (200 ka)

[Data from Markewich and others (1987a)]

Depth

(cm)

0-25 ..........

25-34 .........

34-48 .........

48-70 .........

70-96 .........

96-138 ........

138-170 .......

170-200 .......

200-230 .......

Horizon1

, . . . Ap

A2

B21t

B22t

B23t

B31

B32

Cl

IIC2

Moist color2

10YR4/3

10YR4/6

7.5YR5/6

5YR5/6

5YR5/6

7.5YR5/6

7.5YR5/6

10YR5/8

10YR5/8

Bulk density3 

(g/cm3 )

1.71

1.81

1.71

1.63

1.63

1.58

5 1.70

5 1.70

5 1.70

Texture4

Is

si

si

scl

Is

s

s

s

s

Clay

(<2 |jim) 

(percent)

6.9

8.9

15.3

17.8

10.5

7.2

5.6

4.3

2.7

Fe2O3 +AI 2O3

SiO2 

(percent)

4.4

6.5

9.4

10.3

6.5

4.8

5.2

1.9

3.1

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4ls, loamy sand; si, sandy loam; scl, sandy clay loam; s, sand.

Estimated.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D31
Site B-2. 23-m terrace, Rappahannock River Valley (600 ka)

[Data from Markewich and others (1987a)]

Depth

(cm)

0-23 ..........

23-30 .........

30-44 .........

44-67 .........

67-94 .........

94-124 ........

124-148 .......

148-162 .......

Horizon1

. . . . Ap

Bl

B21t

B22t

B23t

B24t

B25t

B26t

Moist color2

10YR4/3

10YR4/3

7.5YR4/4

10YR5/6

5YR4/6

5YR5/6

5YR5/6

5YR5/6

Bulk density3 

(g/cm3 )

1 44

1.61

1.57

1.50

1.54

1.58

1.47

1.46

Texture4

sil

sil

sil

sicl

sicl

sicl

sicl

sicl

Clay

(<2 |xm) 

(percent)

16.0

18.8

26.6

34.5

35.3

34.8

34.5

32.4

Fe2O3 +AI 2O3

SiO2 

(percent)

16.5

17.7

22.2

28.6

30.1

33.5

37.3

35.9

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4sil, silty loam; sicl, silty clay loam.

Site B-3. 45-m terrace, Rappahannock River Valley (1 Ma)

[Data from Markewich and others (1987a)]

Depth

(cm)

0-12 ..........

12-28 .........

28^3 .........

43-60 .........

60-84 .........

84-112........

112-146.......

146-175 .......

175-213.......

213-250.......

Horizon1

A2

B21t

B22t

B23t

B24t

B25t

B26t

B27t

B28t

Moist color2

10YR4/2

10YR4/3

10YR4/3

5YR4/6

2.5YR4/6

2.5YR4/6

2.5YR4/6

2.5YR4/6

2.5YR4/6

2.5YR4/6

Bulk density3 

(g/cm3 )

1.18

1.67

1.55

1.52

1.49

1 53

5 1.50

1.48

5 1.50

1 53

Texture4

1

1

1

cl

c

c

c

c

cl

cl

Clay

(<2 (xm) 

(percent)

19.8

23.2

29.4

33.6

37.4

44.0

42.3

47.8

46.4

43.5

Fe2O3 +AI2O3

Si02 

(percent)

13.9

14.0

21.2

22.4

24.5

28.4

27.4

29.3

31.5

27.3

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 l/3 bar.

41, loam; cl, clay loam; c, clay.

Estimated.

D32 Pedologic Studies in the Eastern United States
Site C-1. 39-m terrace, Cape Fear Valley, North Carolina (200 ka)

[Data from H.W. Markewich, M.J. Pavich, and M.J. Mausbach (unpublished data, 1982)]

Depth

(cm)

0-22 ..........

22-34 .........

34-46 .........

46-66 .........

66-90 .........

90-130........

130-160.......

160-180.......

Horizon1

An

A2

B21t

B22t

B23t

B3

Cl

C2

Moist color2

10YR4/1

10YR7/4

10YR6/6

10YR6/6

10YR6/6

10YR6/1

10YR6/1

10YR6/1

Bulk density3

(g/cm3 )

0.70

1.76

1.71

1.76

1.75

1.70

1.65

1.62

Texture4

Is

Is

cpl

scl

Cl

c

c

Clay 

(<2 |xm) 

(percent)

2.4

8.4

16.5

18.6

25.1

32.8

32.4

32.0

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4ls, loamy sand; scl, sandy clay loam; cl, clay loam; c, clay.

Site C-2. 30-m terrace, Cape Fear Valley, North Carolina (60 ka)

[Data from H.W. Markewich, M.J. Pavich, and M.J. Mausbach (unpublished data, 1982)]

Depth

(cm)

0-11 ..........

1 1-26 .........

26-53 .........

53-77 .........

77-114........

114-140.......

140-190 .......

190-226 .......

226-276 .......

Horizon1

An

Bl

B21t

B22t

B3

Cl

C2

C3

2C4

Moist color2

10YR6/4

10YR4/4

7.5YR5/6

7.5YR5/6

7.5YR5/6

7.5YR5/6

10YR5/6

10YR6/8

10YR5/1

Bulk density3 

(g/cm3)

1.37

1.59

1.56

1.56

1 54

1.60

1.65

1.60

1.62

Texture4

fsl

fsl

scl

sicl

sil

fsl

fsl

fsl

sicl

Clay 

(<2 (jun) 

(percent)

7.4

10.9

21.0

22.7

21.5

15.7

16.9

15.8

23.6

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4fsl, fine sandy loam; scl, sandy clay loam; sicl, silty clay loam; sil, silty loam.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D33
Site C-3. 30-m terrace, Cape Fear Valley, North Carolina (60 ka)

[Data from H.W. Markewich, M.J. Pavich, and M.J. Mausbach (unpublished data, 1982)]

Depth

(cm)

0-1 1 ..........

11-29.........

29^3 .........

43-65 .........

65-93 .........

93-147 ........

147-199 .......

199-250 .......

Horizon1

Al

A2

B21t

B22t

B23t

B3

Cl

C2

Moist color2

10YR4/1

10YR7/2

10YR5/4

10YR5/6

10YR7/2

10YR6/2

10YR5/6

10YR6/4

Bulk density3 

(g/cm3)

1.11

1.52

1.71

1.66

1.60

1.63

1.66

1.60

Texture4

fsl

fsl

cl

c

cl

Is

fs

Clay 

(<2 urn) 

(percent)

22.0

13.0

21.2

30.1

28.5

22.8

12.9

6.0

Horizon designations from Soil Survey Staff (1962). 

2Munsell notation. 

3 1/3 bar. 

4fsl, fine sandy loam; cl, clay loam; c, clay; Is, loamy sand; fs, fine sand.

Site C-4. 45-m terrace, Cape Fear Valley, North Carolina (200 ka)

[Data from H.W. Markewich, M.J. Pavich, and M.J. Mausbach (unpublished data, 1982)]

Depth

(cm)

0-18 ..........

18^8 .........

48-64 .........

64-84 .........

84-104 ........

104-124 .......

124-158 .......

158-210.......

Horizon1

, . . . Ap

B21t

B22t

B23t

B24t

B25t

B26t

2C

Moist color2

10YR4/2

10YR5/6

10YR5/6

10YR5/6

10YR5/6

10YR5/4

10YR6/1

10YR6/1

Bulk density3

(g/cm3 )

1.78

1.75

1.66

1.74

1.69

1.75

1.79

1.66

Texture4

Is

scl

scl

scl

scl

scl

c

Clay 

(<2 (jun) 

(percent)

2.4

20.2

22.2

28.7

30.7

27.8

26.2

34.7

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4ls, loamy sand; scl, sandy clay loam; c, clay.

D34 Pedologic Studies in the Eastern United States
Site F-1. Augusta, Ga. (10 Ma)

[Data from Pavich and others (1981). , no data]

Depth

(cm)

0-15 ..........

15^8 .........

48-73 .........

73-100 ........

100-126.......

126-139.......

139-157.......

157-182.......

182-322.......

322-352 .......

352-418.......

418-480.......

480-519.......

519-625.......

625-707 .......

707-763 .......

Horizon1

Al

A21

A22

A23

A/B

B/A

B21

B22

B23t

2B24tb

3B25tb

3B26tb

3B27tb

3B31b

3B32b

Cb

Moist color2

10YR5/4

10YR6/4

10YR6/4

10YR6/6

10YR6/6

10YR6/4

7.5YR5/6

7.5YR5/6

10R4/8

10R4/8

10R4/8

10R4/8

10R4/8

10R4/9

2.5YR4/8

2.5YR4/8

Bulk density3 

(g/cm3 )

1.40

1.60

1.70

1.70

1.74

1.70

1.68

1.70

1.78

1.70

1.67

1.70

1.70

1.75

1.70

1.74

Texture4

Is

s

s

s

Is

si

si

si

si

fsl

fsl

si

si

fsl

Ifs

Is

Clay

(<2 (Jim) 

(percent)

5.7

2.4

4.0

6.8

9.6

20.2

33.7

35.7

37.1

56.0

49.4

46.8

46.3

40.5

23.6

16.7

Fe2O3 +AI2O3

SiO2 

(percent)

3

11

38

31

31

26

29

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4ls, loamy sand; s, sand; si, sandy loam; fsl, fine sandy loam; Ifs, loamy fine sand.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D35
Site F-2. Augusta, Ga. (2.5 Ma)

[Data from Pavich and others (1981). , no data]

Depth

(cm)

0-33 ...........

33-112.........

112-157........

157-196........

196-222 ........

222-271........

271-323........

323-356 ........

356^00 ........

400^67 ........

467^92 ........

492-558 ........

558-636 ........

636-690 ........

690-738 ........

738-797 ........

797-828 ........

828-860 ........

860-940 ........

940-1034 .......

1034-1070......

Horizon1

Al

A21

A22

Bl

B21t

B22t

B23t

B24t

B25t

B26t

B31

B32

C2

2B21tb

2B22tb

2B3b

3B2b

3B31b

3B32b

3B33b

Moist color2

10YR5/1

10YR6/6

10YR6/6

7.5YR5/6

7.5YR5/6

2.5YR5/6

2.5YR4/6

2.5YR4/6

2.5YR4/8

2.5YR4/8

5YR5/6

5YR5/6

10YR6/8

10YR5/6

5YR5/6

7.5YR5/6

7.5YR5/6

2.5YR4/6

2.5YR5/8

5YR5/6

5YR5/8

Bulk density3 

(g/cm3)

1.50

1.60

1.60

1.70

1.85

1.86

1.80

1.80

1.80

1.81

1.80

1.80

1.80

1.79

1.89

1.90

1.87

1.82

1.84

1.80

1.73

Texture4

s

s

s

s

si

scl

scl

scl

scl

scl

scl

si

scl

scl

si

si

scl

sil

si

scl

Clay Fe2 03 +AI203

(<2 (Am) SiO2 

(percent) (percent)

2.9 -

2.4 3

2.8 14

9.3 16

19.7 -

22.1 -

27.0 -

33.5 11

22.9 -

30.6 -

18.9 -

14.5 -

22.5 -

24.1 -

16.9 -

15.7 -

20.5 -

30.2 -

19.3 -

20.9 -

33.4 -

'Horizon designations from Soil Survey Staff (1962).

2Munsell notation.

3 1/3 bar.

4s, sand; si, sandy loam; scl, sandy clay loam; sil, silty loam.

Site F-3. Augusta, Ga. (100 ka)

[Data from Pavich and others (1981). , no data]

Depth

(cm)

0-7 ...........

7-22 ..........

22-40 .........

40-64 .........

64-84 .........

84-110........

110-137.......

137-171.......

171-192.......

192-221 .......

221-263.......

263-290 .......

Horizon1

Al

Bl

B21t

B22t

B23t

B24t

B25t

B26t

B31

B32

Cl

C2

Moist color2

5YR4/3

2.5YR3/2

10R3/6

10R3/6

10R4/6

10R4/6

10R4/6

2.5YR4/6

2.5YR4/8

2.5YR4/8

2.5YR5/8

10YR8/3

Bulk density3

(g/cm3 )

1.36

1.60

1.66

1.60

1.63

1.60

1.71

1.70

1.66

1.64

1.60

1.60

Texture4

si

scl

scl

scl

scl

scl

scl

scl

si

Ics

cs

cs

Clay

(<2 (jun) 

(percent)

18.0

28.5

41.0

37.0

36.2

34.5

35.7

29.6

15.7

6.4

4.8

1.2

Fe2 03 +Al2 03

SiO2 

(percent)

12

2

'Horizon designations from Soil Survey Staff (1962).

'Munsell notation.

3 1/3 bar.

3 sl, sandy loam; scl, sandy clay loam; Ics, loamy coarse sand; cs, coarse sand.

D36 Pedologic Studies in the Eastern United States
Site G-1. Alluvial fan, Pine Mountain, Georgia (5 Ma)

[Data from Markewich and others (1987b)]

Depth

(cm)

0-18 ..........

18^5 .........

45-69 .........

69-97 .........

97-146 ........

146-175 .......

175-205 .......

Horizon1

AP

AB

BA

Btl

Bt2

Bxl

Bx2

Moist color2

10YR4/3

10YR5/6

7.5YR5/6

7.5YR5/8

7.5YR5/8

2.5YR5/8-10YR5/8

2.5YR4/8-10YR5/8

Bulk density3

(g/cm3)

1.38

1.50

1.60

1.64

1.71

1.70

2.16

Texture4

si

si

si

scl

crcr*]

Clay 

(<2 (Jim) 

(percent)

9.0

5.0

10.5

23.0

30.3

26.5

28.3

'Horizon designations from Soil Management Support Services (1986).

2Munsell notation.

3 1/3 bar.

4sl, sandy loam; scl, sandy clay loam; gscl, gravelly sandy clay loam.

Site G-2. Alluvial fan, Pine Mountain, Georgia (5 Ma)

[Data from Markewich and others (1987b)]

Depth

(cm)

0-15 ..........

15-44 .........

44-66 .........

66-98 .........

98-130 ........

130-164.......

164-195 .......

195-235 .......

235-250 .......

Horizon1

An

Btl

Bt2

Bt2

2Bxl

2Bx2

2Bx3

2Bx4

2Bx5

I 

Moist color2

10YR5/3

2.5YR4/8

2.5YR4/8

2.5YR4/8

2.5YR4/8

2.5YR4/8

2.5YR4/8-7.5YR5/6

2.5YR4/8-10YR5/8

2.5YR4/8-10YR5/8

Sulk density3

(g/cm3 )

1.54

1.43

1.30

1.39

1.68

1.71

1.80

1.75

1.73

Texture4

si

cl

cl

scl

scl

scl

si

si

Clay

(<2 (JLltl)

(percent)

8.8

51.7

44.7

48.0

40.2

30.0

28.7

30.2

32.6

'Horizon designations from Soil Management Support Services (1986).

2Munsell notation.

3 1/3 bar.

4sl, sandy loam; cl, clay loam; scl, sandy clay loam; s, sand.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D37
Site H-1. Uphapee Creek, Alabama (7.5 ka) 

[Data from Markewich and others (1988)]

Depth

(cm)

0-26 ....

26^7 . . .

47-73 . . .

73-97 . . .

97-115..

115-130.

130-170 .

170-200 .

Horizon1

An

......... Bwl

......... Bw2

......... Bw3

......... Bw4

......... BC

......... Cl

......... C2

Moist color2

10YR4/3 

10YR5/3 

10YR5/4 

7.5YR4/4 

10YR5/6 

10YR5/6 

10YR6/6 

10YR7/2

'Horizon designations from Soil Management Support Services 

2Munsell notation. 

3 1/3 bar. 

4fsl, fine sandy loam; cl, clay loam; vfsl, very fine sandy loam

Site H-2. Uphapee Creek, Alabama (6.5 ka)

[Data from Markewich and others (1988). , no data]

Depth

(cm)

0-20 ....

20-36 . . .

36-58 . . .

58-78 . . .

78-112..

112-146.

146-176 .

206-230 .

Horizon1

......... A

......... E

......... Bw

......... Bwgl

......... Bwg2

......... Btgl

......... Btg2

Cl

Moist color2

10YR3/2 

10YR5/3 

5YR4/4 

10YR6/2 

10YR6/1 

10YR6/1 

10YR6/1

Bulk density3

(g/cm3)

1.46 

1.36 

1.43 

1.42 

1.48 

1.53 

1.46 

1.51

(1986). 

; Ifs, loamy fine sand;

Bulk density3

(g/cm3)

1.44 

1.63 

1.51

1.47 

1.53 

1.50 

1.61

Texture4

fsl 

fsl 

fsl 

cl 

vfsl 

fsl 

Ifs 

fs

fs, fine sand.

Texture4

fsl 

fsl 

cl 

c 

c 

c 

sc

g

Clay 

(<2 (jun) 

(percent)

7.4 

12.2 

11.7 

27.1 

22.5 

16.7 

8.5 

1.2

Clay 

«2 (Am) 

(percent)

7.8 

7.3 

36.1 

50.1 

40.8 

40.1 

26.6

'Horizon designations from Soil Management Support Services (1986).

2Munsell notation.

3 1/3 bar.

4fsl, fine sandy loam; cl, clay loam; c, clay; sc, sandy clay; g, gravel.

D38 Pedologic Studies in the Eastern United States
Site H-3. Tallapoosa River, Alabama (6.5 ka)

[Data from Markewich and others (1988). , no data]

Depth

(cm)

0-22 ..........

22-47 .........

47-66 .........

66-89 .........

89-123 ........

123-161.......

161-190.......

190-215.......

Horizon1

... Ap

Bw

Btl

Bt2

Bt3

Bt3

BC

C

Moist color2

10YR4/3

7.5YR4/4

7 5YR4/4

10YR5/6

10YR5/8

10YR5/8

7 5YR4/4

Bulk density3 

(g/cm3)

1.43

1.45

1.50

1.56

1.60

1.56

1.60

1.60

Texture4

sil

sic

cip

Qlf*

cipl

1

Clay 

(<2 (Jim) 

(percent)

14.8

46.6

43.1

40.2

25.3

26.4

12.9

3.2

'Horizon designations from Soil Management Support Services (1986).

'Munsell notation.

3 1/3 bar.

4sil, silty loam; sic, silty clay; sicl, silty clay loam; 1, loam; s, sand.

Site H-4. Tallapoosa River, Alabama (5.5 ka)

[Data from Markewich and others (1988)]

Depth

(cm)

0-8 ...........

8-30 ..........

30-54 .........

54-94 .........

94-130........

130-64........

164-190.......

Horizon1

A

Bwl

Bw2

Bw3

Bw4

BC

C

Moist color2

10YR3/3

7.5YR5/6

7.5YR5/6

10YR5/6

7.5YR5/6

7.5YR5/6

10YR6/1

Bulk density3

(g/cm3)

1.40

1.41

1.50

1.44

1.50

1.52

1.50

Texture4

sil

sicl

sicl

sicl

sil

1

Clay 

(<2 (Jim) 

(percent)

20.7

38.1

37.1

33.8

30.4

22.4

18.3

'Horizon designations from Soil Management Support Services (1986).

2Munsell notation.

3 1/3 bar.

4sil, silty loam; sicl, silty clay loam; 1, loam.

Soil and Weathering Profile Data in Coastal Plain Chronosequence Studies D39



SELECTED SERIES OF U.S. GEOLOGICAL SURVEY PUBLICATIONS

Periodicals

Earthquakes & Volcanoes (issued bimonthly). 

Preliminary Determination of Epicenters (issued monthly).

Technical Books and Reports

Professional Papers are mainly comprehensive scientific reports of 

wide and lasting interest and importance to professional scientists and engineers. Included are reports on the results of resource studies and of 

topographic, hydrologic, and geologic investigations. They also include 

collections of related papers addressing different aspects of a single scientific topic.

Bulletins contain significant data and interpretations that are of lasting scientific interest but are generally more limited in scope or 

geographic coverage than Professional Papers. They include the results 

of resource studies and of geologic and topographic investigations; as well 

as collections of short papers related to a specific topic.

Water-Supply Papers are comprehensive reports that present significant interpretive results of hydrologic investigations of wide interest 

to professional geologists, hydrologists, and engineers. The series covers 

investigations in all phases of hydrology, including hydrogeology, 

availability of water, quality of water, and use of water.

Circulars present administrative information or important scientific 

information of wide popular interest in a format designed for distribution 

at no cost to the public. Information is usually of short-term interest.

Water-Resources Investigations Reports are papers of an interpretive nature made available to the public outside the formal USGS publications series. Copies are reproduced on request unlike formal USGS 

publications, and they are also available for public inspection at 

depositories indicated in USGS catalogs.

Open-File Reports include unpublished manuscript reports, maps, 

and other material that are made available for public consultation at 

depositories. They are a nonpermanent form of publication that may be 

cited in other publications as sources of information.

Maps

Geologic Quadrangle Maps are multicolor geologic maps on 

topographic bases in 71/2- or 15-minute quadrangle formats (scales mainly 1:24,000 or 1:62,500) showing bedrock, surficial, or engineering geology. Maps generally include brief texts; some maps include structure 

and columnar sections only.

Geophysical Investigations Maps are on topographic or planimetric 

bases at various scales; they show results of surveys using geophysical 

techniques, such as gravity, magnetic, seismic, or radioactivity, which 

reflect subsurface structures that are of economic or geologic significance. 

Many maps include correlations with the geology.

Miscellaneous Investigations Series Maps are on planimetric or 

topographic bases of regular and irregular areas at various scales; they 

present a wide variety of format and subject matter. The series also includes 71/2-minute quadrangle photogeologic maps on planimetric bases 

which show geology as interpreted from aerial photographs. Series also 

includes maps of Mars and the Moon.

Coal Investigations Maps are geologic maps on topographic or 

planimetric bases at various scales showing bedrock or surficial geology, stratigraphy, and structural relations in certain coal-resource areas.

Oil and Gas Investigations Charts show stratigraphic information 

for certain oil and gas fields and other areas having petroleum potential.

Miscellaneous Field Studies Maps are multicolor or black-andwhite maps on topographic or planimetric bases on quadrangle or irregular areas at various scales. Pre-1971 maps show bedrock geology 

in relation to specific mining or mineral-deposit problems; post-1971 

maps are primarily black-and-white maps on various subjects such as 

environmental studies or wilderness mineral investigations.

Hydrologic Investigations Atlases are multicolored or black-andwhite maps on topographic or planimetric bases presenting a wide range 

of geohydrologic data of both regular and irregular areas; principal scale 

is 1:24,000 and regional studies are at 1:250,000 scale or smaller.

Catalogs

Permanent catalogs, as well as some others, giving comprehensive listings of U.S. Geological Survey publications are available under 

the conditions indicated below from the U.S. Geological Survey, Books 

and Open-File Reports Section, Federal Center, Box 25425, Denver, 

CO 80225. (See latest Price and Availability List)

"Publications of the Geological Survey, 1879-1961" may be purchased by mail and over the counter in paperback book form and as a 

set of microfiche.

"Publications of the Geological Survey, 1962-1970" may be purchased by mail and over the counter in paperback book form and as a 

set of microfiche.

"Publications of the U.S. Geological Survey, 1971-1981" may be 

purchased by mail and over the counter in paperback book form (two 

volumes, publications listing and index) and as a set of microfiche.

Supplements for 1982,1983,1984,1985,1986, and for subsequent 

years since the last permanent catalog may be purchased by mail and 

over the counter in paperback book form.

State catalogs, "List of U.S. Geological Survey Geologic and 

Water-Supply Reports and Maps For (State)," may be purchased by mail 

and over the counter in paperback booklet form only.

"Price and Availability List of U.S. Geological Survey Publications," issued annually, is available free of charge in paperback booklet form only.

Selected copies of a monthly catalog "New Publications of the U.S. 

Geological Survey" available free of charge by mail or may be obtained 

over the counter in paperback booklet form only. Those wishing a free 

subscription to the monthly catalog "New Publications of the U.S. 

Geological Survey" should write to the U.S. Geological Survey, 582 

National Center, Reston, VA 22092.

Note. Prices of Government publications listed in older catalogs, 

announcements, and publications may be incorrect. Therefore, the 

prices charged may differ from the prices in catalogs, announcements, 

and publications.