U.S. GEOLOGICAL SURVEY BULLETIN! 1589-A

Prepared in cooperation with the U.S. Department 

of Agriculture, Soil Conservation Service

Chapter A

Age Relations Between Soils and 

Geology in the Coastal Plain of 

Maryland and Virginia

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

R.L. HALL, R.G. JOHNSON, and P.P. HEARN

Prepared in cooperation with the U.S. Department 

of Agriculture, Soil Conservation Service

Soils developed from dated parent material ranging in age 

from 30,000 to about 1.0? million years have been characterized 

from field descriptions and laboratory analyses; age-related 

trends are documented from field and laboratory data

U.S. GEOLOGICAL SURVEY BULLETIN 1589

PEDOLOGIC STUDIES IN THE EASTERN UNITED STATES: 

RELATIONS TO GEOLOGY
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

UNITED STATES GOVERNMENT PRINTING OFFICE: 1987

For sale by the Books and Open-File Reports Section, U.S. Geological Survey, 

Federal Center, Box 25425, Denver, CO 80225

The use of brand names is for descriptive purposes only and does not imply endorsement by the U.S. Geological 

Survey.

Library of Congress Cataloging in Publication Data

Main entry under title:

Age relations between soils and geology in the Coastal Plain of 

Maryland and Virginia.

(U.S. Geological Survey bulletin: 1589-A)

(Pedologic studies in the Eastern United States, relations to geology)

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

1. Soils Eastern Shore (Md. and Va.) Age. 2. Soils Virginia Rappahannock River Region Age. 3. Soil formation Eastern Shore (Md. and Va.) 4. Soil formation Rappahannock River. 5. Geology Eastern Shore (Md. and Va.)

6. Geology Virginia Rappahannock River Region.

7. Geology, Stratigraphic Recent. I. Markewich, Helaine

W. II. Series. III. Series: U.S. Geological Survey bulletin;

1589-A.

QE75.B9 no. 1589-A 557.3s 85-600233 

[S599.M3] [552'.5]
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 these 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 on constructional landforms and residual soils in 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

CONTENTS

Preface III

Abstract 1

Introduction 1

Physiographic and geologic setting 2

Climate 2

Physiography 2

Geology 2

Field and laboratory methods 4 

Results and discussion 5

Data presentation 5

Classification of soils 8

Physical characteristics 8

Chemical characteristics 10

Mineralogy of the <2 micron fraction 10

The loess problem 12

Age relations 15 

Conclusions 16 

Acknowledgments 17 

References cited 17

FIGURES

1. Map of the Coastal Plain of Virginia, Maryland, and Delaware

2. Cross sections showing:

A , Geology across the southern Delmarva Peninsula 4 

B, Geology at soil sampling sites 6, 7, and 8 on terraces 

of the Rappahannock River 5

3-10. Graphs showing:

3. Texture (on a clay-free basis) and weight percent of the <2 

micron fraction 6

4. Solum thickness of soil profiles plotted against age 9

5. Thickness of argillic (Bt) horizons plotted against age 9

6. Clay mass of solum plotted against age 9

7. Hue of argillic (Bt) horizons plotted against age 9

8. Fe2O3+Al 2O3/SiO2 of sola plotted against age 10

9. Weight percent TiO2 plotted against age 11

10. Weight percent MnO plotted against age 11 

11-18. X-ray diffraction patterns for:

11. Site 1 12

12. Site 2 12

13. Site 3 13

14. Site 4 13

15. Site 5 14

16. Site 6 14

17. Site 7 15

18. Site 8 15

Contents V
19-20. Graphs showing:

19. Ratio of peak heights of 14.2A+4.85A/7.2A+4.5A clay peaks plotted 

against [horizon depth x percent clay per horizon] for sites 3, 5, 7, and 

8 16

20. Variation through time in values of clay, organic carbon, and carbonate in 

soils 17

TABLES

1. Analytical methods and units of expression for analyses conducted at the Soil 

Conservation Service, National Soil Survey Laboratory, Lincoln, 

Nebraska 20

2. Soil horizons at site 1:

A , Description of physical characteristics 21

B , Textural analyses 21

C , Weight percent of oxides 22

D, Analyses of extractable Fe, Al, oxalates, and pH 22

3. Soil horizons at site 2:

A , Description of physical characteristics 22

B, Textural analyses 23

C , Weight percent of oxides 23

D , Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk

density 23

E, Analyses of extractable bases, extractable Al, cation exchange capacity 

(CEC), Al saturation, and pH 24

4. Soil horizons at site 3:

A , Description of physical characteristics 24

B , Textural analyses 24

C , Weight percent of oxides 25

D, Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk

density 25

£, Analyses of extractable bases, extractable Al, cation exchange capacity 

(CEC), Al saturation, and pH 25

5. Soil horizons at site 4:

A , Description of physical characteristics 26

B , Textural analyses 26

C , Weight percent of oxides 26

D, Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk

density 27 

£, Analyses of extractable bases, extractable Al, cation exchange capacity

(CEC), Al saturation, and pH 27

6. Soil horizons at site 5:

A, Description of physical characteristics 28

B , Textural analyses 28

C , Weight percent of oxides 28

D, Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk

density 29

E, Analyses of extractable bases, extractable Al, cation exchange capacity 

(CEC), Al saturation, and pH 29

Vf
7. Soil horizons at site 6:

A, Description of physical characteristics 29

B , Textural analyses 30

C , Weight percent of oxides 30

D, Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk

density 30 

£, Analyses of extractable bases, extractable Al, cation exchange capacity

(CEC), Al saturation, and pH 31

8. Soil horizons at site 7:

A , Description of physical characteristics 31

B , Textural analyses 31

C , Weight percent of oxides 32

D, Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk

density 32

E, Analyses of extractable bases, extractable Al, cation exchange capacity 

(CEC), and pH 32

9. Soil horizons at site 8:

A , Description of physical characteristics 33

B , Textural analyses 33

C , Weight percent of oxides 33

D, Analyses of extractable Fe., Al, and Mn, oxalates, ratio clay, and bulk

density 34

E, Analyses of extractable bases, cation exchange capacity (CEC), 

and pH 34

Contents VH

PEDOLOGIC STUDIES IN THE EASTERN UNITED STATES: RELATIONS TO GEOLOGY

Age Relations Between Soils and Geology in the 

Coastal Plain of Maryland and Virginia

By H.W. Markewich, MJ. Pavich, M.J. Mausbach, 1 R.L. Hall, 2 R.G. Johnson, and P.P. Hearn

Abstract

Soils and their related surfaces on marine and fluvial 

deposits of the Maryland and Virginia eastern shore and on 

similar deposits along the lower reaches of the Rappahannock 

River provide the basis for comparing soil development to soil 

age. In this region, soils, if developed in similar parent material 

on uneroded positions in the landscape, can be used to form a 

chronosequence of landforms based on relative ages. In a few 

areas, where a soil is developed in parent material that has 

been dated by isotopic analysis, a maximum age can be determined for the soil and the surface upon which it has developed. 

Solum thickness, thickness of the argillic horizon, color, and 

clay mass (g/cm 2 summed through solum), as well as the degree of Al and Fe enrichment, indicate that significant differences exist among soils of early Pleistocene (>1.0? m.y.) to late 

Pleistocene (30,000 years) age. In this study soils associated 

with a specific constructional land surface are assumed to be 

only slightly younger than the parent material associated with 

the surface, unless pedogenic data indicate that the surface has 

been eroded and (or) the soil truncated.

Soils that are developed in 25,000- to 35,000-year-old 

parent material have solum thicknesses of 60 to 100 cm, B 

horizons that are 20 to 30 cm thick, clay mass values <10 

g/cm2 , and AI + Fe/Si values <10.0. Soils developed on 60,000- 

to 200,000-year-old parent material have sola that range in 

thickness from 100 to 200 cm, Bt horizons that range in thickness from 90 to 175 cm, clay mass values from 23 to 35 g/cm2 , 

and AI + Fe/Si values from 13.0 to 19.0. Soils that are developed 

on primary surfaces considered to be about 500,000? years in 

age have solum thicknesses greater than 160 cm, Bt horizon 

thicknesses that are greater than 130 cm, clay mass values >80 

g/cm2 , and AI + Fe/Si values greater than 35.0. Soils developed 

on materials estimated to be about 1.0? m.y. in age have solum 

thicknesses >250 cm, Bt horizon thicknesses >220 cm, clay 

mass values > 140 g/cm2 , and AI + Fe/Si values of 25.0 to 27.0, 

somewhat less than the value of 35.0 for soils developed on

500,000-year-old parent material. Soil color varies from 7.5YR 

5/8 for the Bt horizon developed in 25,000- to 35,000-year-old 

parent material to 2.SYR 4/6 for Bt horizons developed in the 

1.0?-m.y.-old parent material. The percent sand of total solids 

decreases with increasing age of soil. Soil structure in the 

argillic horizon changes with this change in texture. Medium 

subangular blocky is the dominant structure of the 60,000- to 

200,000-year-old soils with >50 percent sand (sandy loam and 

loam textures); medium and coarse prismatic is the structure of 

the 500,000?-year- and 1.0?m.y.-old soils with <40 percent 

sand (silty loam, silty clay loam, and clay textures).

Soils developed on 60,000- to 500,000-year-old parent 

material are similar and are difficult to distinguish from each 

other. The Al + Fe/Si value may be the most useful parameter in 

differentiating these soils, but it does not appear to be useful in 

differentiating soils >500,000? years in age. Clay mass, thickness of argillic horizon, and hue may be better indicators of age 

tor early Pleistocene soils.

Nonexpandable hydroxy-interlayered dioctahedral vermiculite (HIV) increases relative to kaolinite and mica with 

increasing age and greater weathering in soils <500,000? years 

in age. Data suggest that kaolinite may increase relative to HIV 

in soils >1.0? m.y. in age.

'U.S. Department of Agriculture, Soil Conservation Service, 

National Soil Survey Laboratory, Lincoln, NE 68508.

2U.S. Department of Agriculture, Soil Conservation Service, 

Easton, MD 21601.

INTRODUCTION

Despite the large volume of literature on Quaternary 

soils of North America, relatively little information is available on soils developed in Pliocene and Quaternary marine 

and fluvial deposits in the mid-Atlantic Coastal Plain 

(Daniels and Gamble, 1978; Daniels and others, 1978; Foss 

and others, 1978; Douglas, 1977). For this region, unlike 

the central plain states and portions of the west coast states 

(Rune, 1969; Follmer, 1978), no systematic study exists 

that relates properties of soils either to the mineralogy or to 

the age of the parent materials. This may be attributed in 

part to the lack of detailed geologic maps of Pliocene and 

Pleistocene units in this part of the Coastal Plain. Over the

Age Relations between Soils and Geology 1
past 10 years, however, detailed geologic information for 

specific areas has become available. As a result, the U.S. 

Geological Survey (USGS) and Soil Conservation Service 

(SCS) undertook a cooperative study to determine whether 

soils and associated weathering profiles, developed in Quaternary marine and fluvial sediments in the Chesapeake Bay 

area, could be used as indicators of relative and (or) absolute 

age of the surfaces and (or) sediments. The purpose of this 

paper is to present data that suggest correlation between soil 

development and the age of the underlying material. Specifically we present (1) detailed chemical and physical data for 

eight soils in the study area; (2) relation of each soil to its 

position in the landscape and to the known or inferred age 

of its parent material; (3) physical and chemical characteristics most useful for pedologic comparison; and (4) for the 

Maryland-Virginia Coastal Plain, a range for each significant characteristic so that an estimate of the numerical age 

can be ascertained for the land surface.

PHYSIOGRAPHIC AND GEOLOGIC SETTING

Climate

The Delmarva Peninsula and the lower Rappahannock River area lie between 75°36'W. and 77°21'W. long 

and 36°54'N. and 39°40'N. lat (fig. 1). The present climate 

is humid continental, with well-defined seasons and mild 

winters. The maximum mean monthly temperature of the 

area studied (1892 to 1981) is 28.9°C in July and 2.0°C in 

January. The mean annual temperature over the period is 

15.2°C. The mid-Atlantic Coast Plain climate is commonly 

less severe than that of regions of the continental interior at 

the same latitude, due to such modifying factors as proximity to the Gulf Stream, Atlantic Ocean, and the Appalachian 

Mountains. The average annual precipitation is 1,118 mm. 

Precipitation is distributed fairly uniformly through the 

year, but parts of the area undergo annual drought and flood. 

Paleontologic evidence suggests that the present climate 

is similar to that of interglacial periods during the past 

3 m.y.

Physiography

The part of the Delaware, Maryland, and Virginia 

Coastal Plain east of the Chesapeake Bay is called the Delmarva Peninsula. The peninsula, a coastal lowland that separates the Chesapeake Bay from the Atlantic Ocean (fig. 1), 

is 50 km across at its widest point and narrows to the north 

and the south. It slopes gently from the highest point in the 

north, 31 m near Elk Neck, to 12 m near Cape Charles. 

Streams are not deeply incised, but progressively older surfaces are more modified by erosion. Although many of the

streams are free flowing in their upper reaches, their lower 

reaches are tidal.

The Rappahannock River, Virginia, drains the Piedmont and Coastal Plain west of Chesapeake Bay and south 

of the Potomac River (fig. 1). Cut and fill fluvial and estuarine terraces flank the lower reaches of the Rappahannock 

River where it flows through the Coastal Plain. Terrace 

morphology changes with terrace age (Colman, 1983) and 

progressively older terraces show increasing drainage density and decreasing preservation of original depositional 

area.

Geology

Sediments of Quaternary age, chiefly near-shore 

marine and estuarine beds, constitute the surface deposits of 

the Delmarva Peninsula. Recent investigations on the Delmarva Peninsula indicate that lower Pleistocene sediments 

are not preserved (Owens and Denny, 1979; Mixon and 

others, 1982). Mixon (1985) indicated that the oldest Pleistocene unit is the 200,000-year-old Accomack Member of 

the Omar Formation (figs. 1, 2A). Mixon (1985) correlated 

the Omar with similar deposits at the mouth of the Rappahannock River that have been dated at 184,000± 

20,000 years by uranium-series analysis of an included coral 

(Mixon and others, 1982). The Nassawadox Formation 

forms the next younger unit on the Delmarva Peninsula 

(Mixon, 1985). On the basis of several uranium-series ages 

on corals, this unit is considered to be between 60,000 and 

125,000 years in age (Mixon and others, 1982) (fig. 2A). 

The Kent Island Formation (Owens and Denny, 1979) is the 

youngest Pleistocene unit (fig. 2A) on the Delmarva Peninsula. A 14C age of 28,450 ±660 years (W^643, U.S. 

Geological Survey Laboratory, Reston, Va.) was obtained 

from disseminated carbon in an organic-rich horizon at 3 m 

depth in the Kent Island Formation 18 m northwest of the 

Eastern Neck Island study site. Three other 14C ages ranging 

from 26,000 to 32,000 years have been obtained for the 

Kent Island Formation (Owens and Denny, 1979). This age 

of about 30,000 years for the Kent Island is disputed, however, because Mixon (oral commun., 1982), on the basis of 

stratigraphic correlations, considered the surface of the unit 

to be between 40,000 and 60,000 years in age. This interpretation implies either that the 14C age is derived from 

organic material deposited after the Kent Island sediments 

were exposed to subaerial weathering or that the organic 

materials are in an active spodic horizon, which would yield 

a younger 14C age than the age of the parent material. Our 

data do not resolve the conflict.

The Omar and the Nassawadox Formations are each 

6- to 25-m-thick deposits of fossiliferous clay, silt, and 

quartz sand; each unit was deposited during at least one 

major marine transgression. The Omar surfaces range in

2 Pedologic Studies in the Eastern United States
PENNSYLVANIA

NEW JERSEY

FREDERICKSBURG V,

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 KILOMETERS

' | | 

Figure 1. Map of the Coastal Plain of Virginia, Maryland, and Delaware showing late Quaternary geology and 

sample site locations.

Age Relations between Soils and Geology 3
2 3 

EXPLANATION

4 MILES

Marine deposits

Kent Island and Sinepuxent Formations

Nassawadox Formation

Omar Formation

Yorktown Formation

Dashed where inferred

Figure 2/4. Cross section showing geology across the southern Delmarva Peninsula (from Mixon, 1985). Location of section 

shown in figure 1.

altitude from 10 to 18m. The Nassawadox surfaces are only 

slightly lower, ranging from 4 to 10 m in altitude. The Kent 

Island Formation is a 12-m-thick unit of thinly bedded sand 

and silt, with surface altitudes of 3 m in Virginia to more 

than 7 m at Eastern Neck Island (Owens and Denny, 1979; 

Mixon, 1985) (figs. 1, 2A).

The terrace at 12 m altitude at the mouth of the Rappahannock River (fig. 25) is a planar surface underlain by 

a transgressive marine sequence of fossiliferous clay and 

cross-bedded quartz sand that ranges from 3 to 12m thick 

(Newell, 1985). The fossiliferous marine clay near the base 

of this unit contained the coral dated at 184,000 ±20,000 

years (uranium-series analysis; Mixon and others, 1982). 

The older 23 m and 45 m altitude terraces along the lower 

Rappahannock River are underlain by fluvial and (or) estuarine sand, silt, and clay that contain little or no evidence of 

marine influence (fig. 2#). Neither terrace contains radiometrically dated material. The 23 m terrace is tentatively 

assigned an age of 500,000? years (Newell, 1985). The 

45 m terrace is tentatively assigned an age of about 1.0? 

m.y. These ages are based upon correlations with the 

Canepatch and Waccamaw Formations, which have been 

dated in the Carolinas (McCartan and others, 1982). The 

source areas for the Rappahannock terrace deposits are the 

crystalline and intrusive rocks of the Piedmont and Blue

Ridge and the mafic intrusives and sedimentary rocks of the 

Mesozoic basins in Virginia.

FIELD AND LABORATORY METHODS

Except for site 1, all soil pedons were described and 

sampled by the authors and local SCS personnel. Horizon 

designations and descriptions follow the Soil Survey Manual (Soil Survey Staff, 1951) format. Analytically split samples were analyzed for standard physical and chemical characteristics (methods used are listed with their numerical 

codes in table 1) at the SCS National Soil Survey Laboratory 

(NSSL). The USGS laboratories conducted additional 

analyses including X-ray diffraction of the <2 micron fraction (glycolated, 350°C, SOOT); bulk chemistry by X-ray 

fluorescence; chemistry of the <63 micron fraction on selected sites; and oxalate extraction and atomic absorption of 

iron and aluminum. Only the X-ray diffraction patterns of 

the untreated <2 micron fraction are presented in the text.

The X-ray fluorescence analyses of the soil samples 

were performed on a Diano 8600 spectrometer after samples 

had been fused with lithium tetraborate. Major-element concentrations were then determined comparing unknown intensities for each element to calibration curves prepared

4 Pedologic Studies in the Eastern United States
SW

Rappahannock 

River

Site? S79VA 179-001 

5 km southeast of Fredericksburg

, ..... : .j Quaternary 

|.-';Qa>.'^ alluvium

Tertiary

Kt0cg°| Chesapeake L^-2 d Group

Cretaceous 

pKp^l Potomac 

~ ~ Formation

 Contact

KILOMETERS

Rappahannock 

River Site 8 S80VA 099-001 

40 km southeast of Fredericksburg

KILOMETERS

N

50 -i

J 40-

(0

* 30-

v

I 20H 

<n

fio-

^ggS^dar: \Rappahannoclc 

River

1 

KILOMETERS

Site 6 S79VA 103-001 

80 km southeast of Fredericksburg

Figure 2B. Cross sections showing geology at soil sampling sites 6, 7', and 8, adjacent to the Rappahannock River 

south of Fredericksburg, Va. Site locations are shown in figure 1.

from USGS silicate rock standards (Flanagan, 1976). This 

method usually results in relative errors of <5 percent.

RESULTS AND DISCUSSION 

Data Presentation

The exact location of each study site and the field 

description of the soil and weathering profile described at

the site are given in tables 2A through 9A. Analytical results 

for samples from the profiles are presented in tables IB-IE 

through 9B-9E. The data are presented by study site. The 

study sites are arranged roughly from youngest to oldest. 

Figure 3 is a graphical presentation of the texture (on a 

clay-free basis) and weight percent of the <2 micron fraction for each profile, plotted by horizon. Figures 4 through 

7 are graphic summaries of solum thickness, thickness of the 

argillic horizon, clay mass, and hue of Bt horizon plotted 

against either the determined or estimated age of the parent

Age Relations between Soils and Geology 5
Eastern Neck: Site 1

PERCENT FINER 

Q0 25 50 75

25

50

(J

75

100 O 

N 

OC 

O

I

O 

to

0 25 50 75 100 

WEIGHT PERCENT <2 JJL FRACTION OF WHOLE SOIL

Joynes Neck: Site 2

PERCENT FINER 

25 50 75

z 

O 

N 

OC

O

I

O to

IIC4

250"0 25 50 75 100 

WEIGHT PERCENT <2 JJL FRACTION OF WHOLE SOIL

Persimmon Point: Site 5

PERCENT FINER

250,

z 

O N

a: 

O

I

O to

Norris Bridge: Site 6

PERCENT FINER 

.0 25 50 75

"0 25 50 75 100 

WEIGHT PERCENT <2 ^ FRACTION OF WHOLE SOIL

0 25 50 75 100 

WEIGHT PERCENT <2 JJL FRACTION OF WHOLE SOIL

Figure 3. Texture (on a clay-free basis) and weight percent of the <2 micron fraction for all sites. 

6 Pedologic Studies in the Eastern United States
Oyster: Site 3

Nelsonia: Site 4

PERCENT FINER 

25 50 75

0 25 50 75 100 

WEIGHT PERCENT <2 JJL FRACTION OF WHOLE SOIL

PERCENT FINER 

25 50 75 100

0 25 50 75 100 

WEIGHT PERCENT <2 ^ FRACTION OF WHOLE SOIL

23 m Terrace: Site 7

PERCENT FINER 

25 50 75

0 25 50 75 100 

WEIGHT PERCENT <2 JJL FRACTION OF WHOLE SOIL

EXPLANATION 

GRAIN SIZE IN MICRONS

50-100

Very fine sand

100-250 

Fine sand

>250 Medium, 

coarse, and 

very coarse sand

45 m Terrace: Site 8

PERCENT FINER 

25 50 75

B28t

250,0 25 50 75 100 

WEIGHT PERCENT <2 JJL FRACTION OF WHOLE SOIL

Figure 3. Continued

Age Relations between Soils and Geology 7
material. Figures 8,9, and 10 show the changes in chemical 

composition with increase in age of the soil: AliC^ + FeiCV 

SiO2 ratio, TiO2 , and MnO, respectively. X-ray diffraction 

patterns of the <2 micron fraction are presented in figures 

11 through 18.

Classification of Soils

Most of the soils developed on the Piedmont and 

Coastal Plain of the middle and southern Atlantic coastal 

states are in the Ultisol soil order. Ultisols are found in the 

middle to low latitudes in areas that in some season experience greater precipitation than evapotranspiration, which 

allows water to move through the solum into the underlying 

parent material (Soil Survey Staff, 1975). In Ultisols, leaching removes bases at about the same rate as they are released 

by weathering. Most bases are held in the vegetation and in 

the upper few centimeters of the soil. Common clay minerals include kaolinite and hydroxy-interlayered vermiculite 

(HIV). Halloysite and gibbsite are also present in small 

amounts. Clay-size quartz, goethite, hematite, and mica are 

also common. Ultisols have a base saturation (by sum of the 

cations) that is <35 percent in the layer 1.5m below the top 

of the argillic horizon or 1.8 m below the ground surface, 

whichever is shallower.

All of the soils described in this study are in the Udult 

suborder of Ultisols. Each of the soils described is in the 

fine-loamy, mixed, thermic Typic Hapludult family, with 

the exception of the fine-loamy, over clayey, mixed, thermic Typic Paleudult that has developed on the 45 m terrace. 

Hapludults are well-drained soils with an ochric epipedon 

and a thin to moderately thick argillic horizon. Hapludults 

are most numerous in the Piedmont, where the land surface 

is predominantly in slope, and on only moderately dissected 

surfaces in the lower Coastal Plain and along the drainages 

of the Coastal Plain and the Piedmont. Paleudults are 

commonly less permeable than Hapludults and are present 

on old stable land surfaces in the upper Coastal Plain and 

outer Piedmont, and on remnants of river terraces located 

two and three terraces above the present floodplain along 

Coastal Plain rivers. Paleudults have thick to very thick 

argillic horizons with low activity clays, similar to the clays 

of Oxisols present in tropical climates. Both Hapludults and 

Paleudults form on acid rocks or sediments that have an 

almost exclusive forest canopy, except where cultivated. In 

the 1938 (modified 1949) soil classification (Thorp and 

Smith, 1949) Hapludults in the thermic temperature regime 

were classified as Red-Yellow Podzolics, and in the mesic 

temperature regime were classified as Gray-Brown Podzolics. Paleudults in the same classification were almost 

exclusively Red-Yellow Podzolics.

Physical Characteristics

Soil texture of the B horizons is progressively finer in 

each older soil from sandy loam and silt loam in the 

30,000-year-old alluvium at Eastern Neck Island, to loam in 

the 60,000-120,000-year-old marine sands at Joynes Neck 

and Oyster, to loam and sandy clay loam in the 200,000- 

year-old marine sands at Nelsonia, Persimmon Point, and 

Norris Bridge, to a silty clay loam in the 500,0007-year-old 

alluvium and (or) estuarine sediments of the 23 m terrace 

and clay loam of the similar 1.0?-m.y.-old sediments of the 

45 m terrace (see tables 2A through 9A for field descriptions 

of soil profiles). Structure of the B horizons changes with 

the change in texture from single grain at Eastern Neck, to 

medium subangular blocky at Joynes Neck, Oyster, and 

Persimmon Point, to medium and coarse subangular blocky 

at Norris Bridge, to medium and coarse prismatic at the 23 

m site and coarse prismatic at the 45 m terrace site. With the 

increase in finer grained material and the change in texture 

from single grain to blocky to prismatic, there is a corresponding increase in thickness of B horizon, which is an 

argillic horizon in all but the youngest (Eastern Neck) profile, from 60 cm for Eastern Neck to >220 cm for the profile 

on the 45 m site. Clay mass (percent clay x bulk density x thickness of horizon integrated over depth of solum) 

also increases with age of solum. Solum thickness increases 

similarly from 90 cm for Eastern Neck to >220 cm for the 

45 m terrace site. See figures 4 and 5 for plots of solum and 

B horizon thickness vs. age of soil. Figure 6 presents the 

plot of clay mass vs. age. A plot of hue of the Bt horizons 

vs. age of solum shows a trend toward increasing redness 

with increasing age (fig. 7).

Textural analysis data, by weight percent, for each 

solum and underlying parent material (where encountered) 

are presented in tables 2B through 9B. Fine-grained and 

very fine grained sand are the dominant sand-size fractions. 

The solum that developed in the 1.0?-m.y.-old 45 m terrace 

alluvium has the most even distribution of sand-size fractions. The Norris Bridge site has the largest percentage of 

medium-size sand distributed through the profile. The silt 

fraction is most evenly distributed between fine and coarse 

silt in the Eastern Neck profile, which is of alluvial and (or) 

estuarine origin. All other profiles on the Delmarva Peninsula have a 2:1 to 3:1 ratio of fine silt to coarse silt in the 

upper 1 m, below which is an abrupt decrease in silt- and 

clay-size fractions and a corresponding increase in total 

percent sand. The profiles of the Delmarva Peninsula all 

have marine sand as parent material. A similar "silt cap" can 

be seen in the profile at Norris Bridge, which also has 

marine sands as parent material. But the profiles in the 

alluvium of the 23 m and 45 m terraces do not show the 

sharp contact between the fine and coarse fraction percentages at 1 m depth; the silt decreases gradually downward 

through the profile.

8 Pedologic Studies in the Eastern United States
*«tv

220

200

180

?

 £ 160

S

3 140

o

CO

u. 120

0

W 100

UJ

Z

0 80

31

60

40

20

o

i l i l l l f l i i l I f I 1 l

EXPLANATION li)A_

 Measured thickness to base of solum

_ A Measured thickness where base of _

solum not reached in trench 

( ) Site number _i«»

-

_

(1)

^

-

~

-

I I l I I I l I

 »-' _

/O) _

' J6> (7)

A

 ' (4)

» _

1 1 1 1 1 l 1 1

240

220

200

E

_o

Z 

O

N

E 160 

O

y 140

_l

0 120

oc

u. 100

O

M 80

LU

Z 

0 60

I

40

20

I I I II I I I I I I I

EXPLANATION

 Measured thickness of argillic horizon

~ A Measured thickness where base of argillic 

horizon not reached in trench

_ O Thickness of non-argillic B

( ) Site number

(7)A

~~ (3)0

~

(2)*

-

(5)^

(4)«

(DO (6)^

-

i tit in i ill l i l

k

-

~

~

-

-

-

-

104 1QS 1Q6 % ' ' ' ' " ' 10- 10-

TIME

Figure 4. Solum thickness of soil 

Data from tables 2A through 9A.

140 

130

120

110

S

D100

O

x »-

o

0 80

ocI

H 70 

O

UJ I 60 '

w 50

CM *

E

-§. An -

1 1 1 1 1 1 1 1 1

EXPLANATION 

{ ) Site number

TIME IN YEARS

IN YEARS

profiles plotted against age. Figure 5. Thickness of argillic (Bt) horizons plotted against 

age. Data from tables 2A through 9A.

1 ' ' ! ' ' is1 )*-

_

(7)«

2.5 YR

5 YR

UJ

D

X

7.5 YR

10 YR

I I I t I I I ! I I I I II I 

EXPLANATION

5/6 First number is value (lightness). 

Second number is chroma (strength) (8H

( ) Site number

*5/6 (7)*5/6

(2 & 3), (5)^5/6

(1)«5/6

l l l I I I I I I I I I I

104 106 1

TIME IN YEARS

4/6

-

-

-

0»

Figure 7. Hue of argillic (Bt) horizons plotted against age. Data 

from tables 2A through 9A.

10* 105 

TIME IN YEARS

10'

Figure 6. Clay mass of solum (weight percent clay x bulk density x horizon thickness of each horizon summed for pedon) 

plotted against age. Data from tables 28, C,and D through 98, 

C, and D.

Age Relations between Soils and Geology 9
Chemical Characteristics

General bulk chemistry of each profile is presented in 

tables 1C through 9C, Data are reported as weight percent 

of oxides in each of the soil horizons. The general chemistry 

is similar for each of the soils. As seen in figure 8, the 

Fe2O3+Al2O3/SiO2 ratio increases as soil age increases. 

SiO2 decreases from >90 percent in the B horizons of the 

30,000-year-old soil at Eastern Neck Island, to 66-90 percent in the B horizons of both the 60,000- to 120,000-yearold soils at Joynes Neck and Oyster and the 200,000-yearold soils at Nelsonia, Persimmon Point, and Norris Bridge, 

to 65-75 percent in the B horizons of the 500,0007-year-old 

23 m terrace and the 1.0?-m.y.-old 45 m terrace soils. In the 

same B horizons, A12O3 increases from <5 percent at Eastern Neck, to between 5 and 10 percent in the 60,000- to 

200,000-year-old soils, to about 14 to 17 percent in the 23 m 

terrace soil, and decreases to about 14 percent in the 45 m 

terrace soil. Fe2O3 in the B horizons increases from about 

1.5 percent at Eastern Neck to about 3 percent at Joynes 

Neck and Oyster, to 2.5 to 4.5 percent at Nelsonia, Persimmon Point, and Norris Bridge, to 5 to 8 percent in the 23 m 

terrace soil, and decreases to about 6 percent in the 45 m 

terrace soil. Decreases in SiO2 , A12O3 , and Fe2O3 correspond to a change in clay mineralogy (relative abundance of 

the hydroxy-interlayered vermiculite to kaolinite) in the 

45 m terrace soil as compared to the 23 m terrace or any 

younger soil. TiO2 shows a general trend of increasing in 

successively older soils but nearly doubles in amount from 

the 60,000- to 200,000-year to the 500,0007-year-old soils 

(fig. 9). TiO2 also decreases in the 1.0?-m.y.-old soil (45 m 

terrace soil) relative to the 500,0007-year-old soil (23 m 

terrace soil). MnO shows an increasing trend similar to that 

of TiO2 but with greater range in the values for a given soil 

and not as clear a decrease between the 23 m and 45 m 

terrace soils (fig. 10).

The ratio of the cation exchange capacity (CEC) to 

percent clay shows a general trend of decreasing in the older 

soils but is similar among the 60,000- to 200,000-year-old 

soils (tables 3D through 9D). This general decrease in the 

ratio in the older soils most likely reflects a progressive 

increase in HIV low charge clay, which results in a decrease 

in the total number of exchange sites. Most of the exchange 

sites that are available are saturated with aluminum.

Mineralogy of the <2 Micron Fraction

Kaolinite, HIV, and quartz are the major components 

of the clay-size fraction of all the Delmarva and Rappahannock River terrace soils. Trends in clay mineralogy of the 

profiles appear to be related to degree of weathering and to 

position within profile. HIV increases toward the surface in

40

35 -

30 -

25

O(N

< 20

+

m

q

u

LL.

- 15

10

5 -

EXPLANATION 

( ) Site number

(5)

(7). 

(7).

(7).

(7).

(7).

(7).

(8).

(8). 

(8)5

(8).

(8).

(3)-

(2).

(3). 

(3).

(1)' (6). 

(4).

104 105 

TIME IN YEARS

I I I

Figure 8. Fe2O3+Al 2O3/SiO2 of sola plotted against age. Data 

from table 2C through 9C.

all but the 45 m terrace profile (figs. 11-18), in which there 

is an apparent increase of kaolinite relative to HIV in the 

weathered parent material (C horizon) in the upper part of 

the B and in the A horizons. Other than the 45 m terrace, 

HIV is more abundant in each older soil. Both the increase 

toward the surface and the increase with age of soil suggest 

that the increase in HIV is a trend associated with degree of 

weathering, at least in soils <500,000? years in age.

In the Oyster profile (fig. 13) we see that HIV and 

gibbsite have strongest peak intensities above and below the 

B23t horizon. In the B23t and 2B24t horizons we see strong 

4.5 A peaks that we interpret as a diffraction peak of halloysite. This peak was shown by scanning electron microscopy to correlate with the occurrence of halloysite in 

horizons of the Pensauken Formation at Betterton, Md., by 

Owens and Minard (1979). We interpret the abundance of 

the halloysite in the argillic horizons as the result of water 

retention in the Bt relative to superjacent and subjacent 

horizons. The higher soil water content of the clay loam B2 

horizon relative to coarser textured Bl and B3 horizons has 

been documented by Bruce and Whisler (1973). We interpret the greater abundance of HIV and gibbsite above and

10 Pedologic Studies in the Eastern United States
*..\j 

1.9

1.8

1.7

1.6

1.5

1.4

1.3

CN

PERCENT Ti

(DON

WEIGHT 00J 

.6

.5

.4

.3

.2

.1

0 

1

I I I I I M I 

EXPLANATION

( ) Site number

-

-

-

-

-

(2). 

(2)-

(1).

(D-

(3).

(3)-

-

(3).

(3).

I I I M M I

0* 106

TIME IN

I I I I M M

(7). 

(7).

(7). 

(7).

(5).

-

-

(8). 

(8)-

-

(5).

(6).

(4).

-

(6)- 

(4)'

-

(4).

-

I I I I M M

106

YEARS

Figure 9. Weight percent TiO2 plotted against age. Data 

from tables 2B through 98.

below the halloysite-rich horizons as reflecting the drier soil 

microenvironments in these horizons that are different from 

the relatively wetter microenvironments in horizons B23t 

and 2B24t. These observations warrant further study in soils 

in which water movement is well understood.

Increase in HIV relative to kaolinite and gibbsite in 

the A horizon could be due to inheritance of HIV transformed from a 10 A precursor or aeolian contribution. However, we hypothesize that the HIV is formed in situ and may 

form preferentially in the A horizons due to chemical processes that attack kaolinite and (or) facilitate in-situ formation of vermiculite. HIV is commonly seen to increase upward into the A horizons of Ultisols (Barnheisel and Rich, 

1966; Rich, 1968; Karathanasis and others, 1983). The relative increase in kaolinite and decrease in HIV in the soil of 

the 45 m terrace are associated with increases in total clay, 

percent clay in the upper horizons, and increase in Fe2O3 

and A12O3 relative to SiO2 , as well as an increase in the total

O

c

hZ

LU

O 

CC

LU

Q_

j_

X

o

LU

*

.33

.32

.31

.30

.29

.28

.27

.26

.25

.24

.23

.22

.21

.20

.19

.18

.17

.16

.15

.14

.13

.12

.11

.10

.09

.08

.07

.06

.05

.04

.03

.02

.01

r>

i I I I I I I I M M I

(6)-

EXPLANATION

_ ( ) Site number _

-

(6)-

-

-

-

(?) 

-

-

-

_

_ 

(8)'

-

(6)- (7).

- (8)» -

(8).

(6).

-

(7)-

-

(2H <8)»

-

(5).

(5)' (8)'

-

(8)»

(2) ' (8).

(2)-

!?! (4)*

< 1 >- (3)- /,»(4);

I II MM I I I M I I I

10" 106 

TIME IN YEARS

106

Figure 10. Weight percent MnO plotted against age. Data 

from tables 2B through 9B.

Age Relations between Soils and Geology 11
Eastern Neck: Site 1 Joynes Neck: Site 2

14.2 14.2

3.33

DEPTH (cm)

AND

HORIZON

13-31 A2

31-43 B21

43-69 B22

69-92 B3

92 4- C

V I GGo K Q

Figure 11. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, Eastern Neck, site 1 (exact 

location and field description in table 2/4). Traces illustrated 

are of oriented, untreated clay. Peak spacings are in angstroms 

(A). Depths to middles of horizons are given in centimeters. V 

is hydroxyl-interlayered vermiculite, I is illite, K is kaolinite, G 

is gibbsite, Go is goethite, and Q is quartz. Vermiculite peak 

intensity increases toward the surface. The illite peak intensity 

decreases above the B22 horizon.

TiO2 (table 9C and figs. 5, 6, 8, and 9). This decrease in 

HIV in the 45 m terrace soil may be due to depletion of the 

source of readily soluble silica. The large percentage of clay 

in the A horizon of this solum may produce a drainage 

environment in which the stability of kaolinite is greater 

than that of HIV and gibbsite (that is, analogous to the B23t 

in the Oyster profile).

In support of this hypothesis, we have plotted the ratio 

of peak heights of

HIV (14 A) + gibbsite (4.8 A) 

kaolinite (7.2 A) + halloysite (4.5 A)

3.54 3.33 DEPTH (cm) AND 

HORIZON

0-28 Ap

28-45 B21t 

45-67 B22t

67-86 B23t 

86-106 B24t

106-122 B25t 

122-146 C1

146-188 C2 

188-202 B'h

V I K GHQ KQ

vs. percent clay x horizon thickness (cm)

Figure 12. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, Joynes Neck, site 2 (exact 

location and field description in table 3/4). Traces illustrated 

are of oriented, untreated clay. Peak spacings are in angstroms 

(A). Depths to middles of horizons are given in centimeters. V 

is hydroxy-interlayered vermiculite, I is illite, K is kaolinite, G 

is gibbsite, H is halloysite, and Q is quartz. Gibbsite peak 

intensity increases both above and below the Bt horizon. The 

ratio of 4.5 A halloysite to 4.85 A gibbsite is a maximum in the 

B24t horizon.

around the lines connecting the maximum and minimum 

ratios. We interpret the existence of the trends as showing 

that the younger, less clay-rich soils have more drainage 

microenvironments in which the formation of HIV and gibbsite occur than do the older soils. We cannot propose a 

simple mechanism to explain the relative phase abundances 

but note that the changes in ratios appear to be related to 

increasing age and decreasing drainage.

for Oyster (site 3), Persimmon Point (site 5), the 23 m 

terrace (site 6) and the 45 m terrace (site 7). Figure 19 shows 

the increase in the HIV and gibbsite above the textural B 

horizons. With increasing depth and clay percentage, the 

ratio decreases. Moreover, going from the youngest soil to 

the oldest soil, the slopes of the hand-drawn best-fit lines 

decrease. For younger soils there is considerable scatter

The Loess Problem

Because the upper 1 m of most soils on the Delmarva 

Peninsula is generally more silty than the lower part of the 

sola, the question arises as to whether or not loess is a 

significant constituent of these soils. The presence of loess

12 Pedologk Studies in the Eastern United States
14.2

3.33

Oyster: Site 3

DEPTH (cm) AND 

HORIZON

0-27 Ap

27-50 B21t

50-70 B22t

70-117 B23t 

117-132 IIB24t

132-147 IIB25t 

147-175 IIB3

175-215 IIC

14.2 Nelsonia: Site 4

G HQ K Q

Figure 13. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, Oyster, site 3 (exact location and field description in table 4/4). Traces illustrated are of 

oriented, untreated clay. Peak spacings are in angstroms (A). 

Depths to middles of horizons are given in centimeters. V is 

hydroxy-interlayered vermiculite, I is illite, K is kaolinite, G is 

gibbsite, H is halloysite, and Q is quartz. Halloysite peak intensity is greatest in the Bt horizon, and vermiculite and-gibbsite 

peak intensities increase above and below the Bt horizon.

on the Eastern Shore was first suggested by Foss and others 

(1978) and Simonson (1982). Each of the pedons sampled 

for this study has a significant percentage of fine silt (2 to 

20 microns) in the Bt horizons. These relatively high silt 

values suggest that there may be a significant fraction of 

aeolian silt (loess) in the total silt fraction of soils on the 

Delmarva Peninsula (Lewis and others, 1984).

The eight sites sampled for this study are in the southern Delmarva Peninsula and adjacent areas and were selected because they appeared to be in uneroded parts of the 

landscape and to have had minimal accretion from aeolian 

and (or) colluvial materials. The soils described by Foss and 

others (1978) average 76 percent silt and 24 percent sand on 

a clay-free basis. Our study profiles average 35 percent silt, 

significantly less than the 76 percent silt reported by Foss 

and others (1978) but much higher than the 5 to 10 percent 

silt below 1 m depth in these sola and in their underlying C 

horizons.

Evidence suggests either that all of the fine silt fraction in soils on the Delmarva Peninsula may not be of

DEPTH (cm) AND 

HORIZON

0-12 Ap 

12-22 A12 

22-46 B21t

40-63 B22t 

63-79 B23t

79-95 B31 

95-121 B32A'2

121-130 B'21 hir

130-150 B'22hir 

150-159 B'23h

159-169 B'24h

V I K G HQ K Q

Figure 14. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, Nelsonia, site 4 (exact 

location and field description in table 5/4). Traces illustrated 

are of oriented, untreated clay. Peak spacings are in angstroms 

(A). Depths to middles of horizons are given in centimeters. V 

is hydroxy-interlayered vermiculite, I is illite, K is kaolinite, G 

is gibbsite, H is halloysite, and Q is quartz. Halloysite peak 

intensity is greatest in the B22t horizon, and vermiculite and 

gibbsite peak intensities increase upward.

loessial origin or that the loess distribution is uneven and 

highly localized. Fine silt percentages do not correlate with 

ages of the Delmarva soils as determined from the geologic 

data. For example, Joynes Neck, (60,000 to 125,000 

years old, site 2) and Nelsonia (140,000 to 220,000 years 

old, site 4) both show much greater percentages of fine silt 

than either Oyster (60,000 to 125,000 years old, site 3) or 

Persimmon Point (140,000 to 220,000 years old, site 5). 

Fine silt in Joynes Neck and Nelsonia, if wind blown, is 

probably of local origin and not part of a widespread loess 

sheet composed dominantly of fine silt. The absence of a 

fine-silt blanket is consistent with Foss and others (1978) 

data that show no downwind sorting of silt or preferential 

transport of fine silt downwind from late Pleistocene sediments of Chesapeake Bay.

Neither does there appear to be any correlation between age of soil and percentage of fine to coarse clay or

Age Relations between Soils and Geology 13
3.33

Persimmon Point: Site 5

DEPTH (cm) AND 

HORIZON

0-24 Ap

24-44 B21t 

44-65 B22t

65-84 B23t

84-99 B24t

99-122 MB25 ir 

122-150 IIB31 

150-173 IIB32 

173-200 IIB33 

200-232 IIC

Norris Bridge: Site 6

14.2

3.33

VI K GHQ K Q

Figure 15. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, Persimmon Point, site 5 

(exact location and field description in table 6/4). Traces illustrated are of oriented, untreated clay. Peak spacings are in 

angstroms (A). Depths to middles of horizons are given in 

centimeters. V is hydroxy-interlayered vermiculite, I is illite, K 

is kaolinite, G is gibbsite, H is halloysite, and Q is quartz. 

Halloysite peak intensity is greatest below the B21t horizon, 

and vermiculite and gibbsite peak intensities increase above 

the B2H horizon.

clay mineralogy in these four pedons. The presence of 

significant amounts of halloysite in the Bt horizons of the 

Oyster and Persimmon pedons does suggest that there has 

been significant in-situ development of clay which, based 

upon the Norris Bridge pedon, would appear to be contemporaneous with development of fine silt (Pavich, unpub. 

data). The absence of halloysite does not, however, 

preclude in-situ development of clay and silt in the Joynes 

Neck and Nelsonia sites. Since the halloysite structure does 

not easily survive aeolian transport, the clay in the Oyster 

and Persimmon Point pedons is considered to be pedogenic 

in origin (formed in situ).

Aeolian silt and clay are probably significant contributors to at least two of the Delmarva sites. The best evidence 

for an aeolian origin for silt and clay is the correlation of the 

fine silt bulge with an HIV-rich epipedon in the younger

DEPTH (cm) AND 

HORIZON

0-25 Ap

25-34 A2

34-48 B21t

48-70 B22t

70-96 B23t

96-138 B31

138-170 B32

170-200 C1

200-230 IIC2

K L GHQGo K Q F

Figure 16. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, Norris Bridge, site 6 (exact location and field description in table 7A). Traces illustrated are of oriented, untreated clay. Peak spacings are in 

angstroms (A). Depths to middles of horizons are given in 

centimeters. V is hydroxy-interlayered vermiculite, I is illite, K 

is kaolinite, G is gibbsite, H is halloysite, L is lepidocrosite, Go 

is goethite, F is K-feldspar, and Q is quartz. Vermiculite peak 

intensity increases toward the surface and kaolinite peak intensity is strong throughout the profile.

soils. In Nelsonia and Joynes Neck, the strong aeolian input 

is indicated by fine silt and correlates with a high ratio of 

HIV/halloysite through the profile. Fine silt is less abundant 

and the ratio of HIV/halloysite is lower in Oyster and Persimmon Point soils, which also have higher ratios of fine to 

coarse clay. This complicates the interpretation of the genesis of those soils and points out the need for further study of 

the source and distance of transport of the loess.

Sites on the Rappahannock River show an increase of 

fine silt with age. In site 6, the production of fine quartz silt 

from the breakdown of coarser grains has been documented

14 Pedologic Studies in the Eastern United States
14.2

23 m Terrace: Site 7

14.2

3.54

7.2

DEPTH (cm) AND 

HORIZON

0-23 Ap 

23-30 B1

30-44 B21 t

44-67 B22t 

67-94 B23t

94-124 B24t 

124-148 B25t

148-162 B26t

V I KQ

Figure 17. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, 23 m terrace, site 7 (exact 

location and field description in table 8/4). Traces illustrated 

are of oriented, untreated clay. Peak spacings are in angstroms 

(A). Depths to middles of horizons are given in centimeters. V 

is hydroxy-interlayered vermiculite, I is illite, K is kaolinite, G 

is gibbsite, H is halloysite, and Q is quartz. Kaolinite is the 

dominant clay mineral in all horizons, and vermiculite peak 

intensity increases in the A horizons.

(Pavich , unpub. data). It appears likely that an in-situ 

pedogenic origin for fine silt is significant in the Rappahannock profiles. The large mass of clay found on the older 

Rappahannock terraces, the clay mineralogy, and the bulk 

chemistry cannot be explained by a simple accumulation of 

aeolian HIV and quartz through time. Addition of highly 

siliceous aeolian material through time would not produce a 

trend of increasing Fe2O3 + Al2O3/SiO2, and the observed 

chemical trend is not consistent with an aeolian origin of silt 

and clay in these profiles (fig. 8).

From this study it is clear that there are two probable 

sources of fine silt in the A and B horizons of these pedons. 

Thus despite evidence for aeolian sediment transport (such 

as dunes and silt caps) care must be taken not to interpret all 

silty epipedons as loessial in origin. Scanning electron microscopy and oxygen isotope data (such as used by Sayin 

and Jackson, 1973) may help resolve the origin of the fine 

silt.

45 m Terrace: Site 8

DEPTH (cm) AND 

HORIZON

0-12 Ap

12-28 A2 

28-43 B21t

60-84 B23t 

84-112 B24t 

112-146 825t

146-175 826t 

175-213 827t

213-250 828t

V I K G HQ KQ

Figure 18. X-ray diffraction patterns for untreated <2 micron 

fractions from selected soil horizons, 45 m terrace, site 8 (exact 

location and field description in table 9/4). Traces illustrated 

are of oriented, untreated clay. Peak spacings are in angstroms 

(A). Depths to middles of horizons are given in centimeters. V 

is hydroxy-interlayered vermiculite, I is illite, K is kaolinite, G 

is gibbsite, H is halloysite, and Q is quartz. Kaolinite is the 

dominant clay mineral in all horizons, and vermiculite does 

not show an increase in intensity in the near-surface horizons.

Age Relations

As mapped, the marine deposits on the southern Delmarva Peninsula comprise a chronosequence of barrier, 

backbarrier, and (or) estuarine sediments deposited at successively lower sea levels. Alternatively, as suggested by 

Hack (1955), the Piedmont and Coastal Plain of Virginia 

and Maryland have been undergoing regional uplift since 

the late Tertiary, thereby resulting in an off-lap sequence of 

Pleistocene marine sediments. The terraces along the Rappahannock River also suggest either a progressive lowering 

of sea level or regional uplift during the Pliocene and Pleistocene. Preserved soil profiles on marine and fluvial terraces

Age Relations between Soils and Geology 15
tn 6

o 4 

P 

I 3

UJ

. 

O

1°

tr

EXPLANATION

 Oyster: Site 3

A Persimmon Point: Site 5

Y = 301.8-64.8(l« X)2 -0.1(1« X)

200 400 600 800 1000 1200 1400 1600 1800 

PERCENTAGE CLAY x DEPTH (cm)

o

CO 4 1-

I

iTi [fl

X oq

o! ^

u. «- 

O

< o3

Csj

1

O

t n

EXPLANATION

 23 m Terrace: Site 7

i o 45 m Terrace: Site 8

- o

* a. o. o 0

 * I 1 1 1 I

0 1000 2000 3000 4000 5000 6000 

PERCENTAGE CLAY x DEPTH (cm)

B

Figure 19. Ratio of peak heights of 14.2 A+4.85 A/7.2 A+4.5 

A peaks plotted against [horizon depth x percent clay per horizon] for (A) sites Sand 5, and (B} sites 7 and 8. Peak 

heights measured from untreated X-ray diffraction patterns, 

figures 13, 15, 17, and 18. Textural data from tables 4B, 6B, 

8B, and 98.

in this landscape increase in degree of development with 

increase in altitude. The grossly similar grain-size 

distributions (tables 2B through 9B and figure 3) for soils on 

the various surfaces and the common source of parent material yield a chronosequence of soils ranging in age from 

about 30,000 to >1.0? m.y.

It is difficult to isolate certain physical characteristics 

such as soil color or thickness of solum (A and B horizons) 

from the chemical processes that produce them. However, 

plots of growth curves (changes of property over time) for 

physical and chemical characteristics (figs. 5 through 10) 

show similarities and divergences. The physical properties 

of redness, clay mass, and solum thickness suggest a step, 

or plateau, in growth curves at about 60,000 to 220,000 

years and a subsequent increase in rate of development from 

500,000? to > 1.0? m.y.

A third-degree polynomial (least squares) equation 

fits the data for redness of the Bt horizons better than a linear 

equation because the standard error of the estimate of a 

linear regression is 33.7, and this error is 0.8 for the thirddegree polynomial. The equation is

where

Y is redness and

X is the natural log of age.

The inflection point of the curve is between 200,000 and 

500,000 years. The data suggest, therefore, that the plateau 

at 60,000 to 220,000 years defines an upper limit of rapid 

soil development. Similar results are obtained by fitting 

equations to the other physical properties. The chemical 

property Al^C^ + Fe^C^/SiC^ ratio does not have this 

plateau. These curves indicate that properties change with 

time but at different rates and that in combination they can 

be used to determine the age of a soil.

Birkeland (1974, p. 131) suggested hypothetical variations in several soil properties with time (fig. 20). His 

curves representing accumulation of organic carbon and 

clay are similar in that they both show steep positive slopes 

of rapid accumulation that level off to zero. The flat slopes 

represent a hypothetical stage of soil development during 

which no change in a particular soil property takes place. 

This can be considered to be a steady-state, or equilibrium, 

for that particular property. The plateau in the physical 

properties of the Maryland and Virginia Coastal Plain soils 

may indicate such steady states. However, after a certain 

period of little change, the properties again begin to change 

with time. The contrast of results of this study with those of 

others (Birkeland, 1974; Simonson, 1978) is possibly due to 

a lack of measurement of all properties of pedogenic origin 

in soils 1.0? m.y. old or older. Evidence presented here, that 

soil properties do continue to change throtigh time, is corroborated by studies by Harden and Marchand (1977), McFadden and others (1982), and Harden (1982).

CONCLUSIONS

Soils developed on surfaces ranging in age from 

30,000 to 1.0? m.y. and underlain by texturally and mineralogically similar parent materials provide a means to study 

change of properties with age of surface. Physical properties 

of clay mass, redness, and solum thickness increase with 

time, except for a period of no change (steady state?) between 100,000 and several hundred thousand years. All 

physical properties studied show a dynamic nature, even in 

soils of ages greater than 1.0? m.y. Chemical properties 

such as the Al2O3+Fe2O3/SiO2 ratio appear to increase at a 

constant rate.

It is relatively easy to characterize the differences 

between the 30,000-year- and the 100,000- to 200,000- 

year-old sola, the 200,000- and 500,00?-year-old sola, and 

the 500,000?- and 1.0?-m.y.-old sola. It is not easy to 

differentiate soils between the 60,000- and 200,000-year16 Pedologic Studies in the Eastern United States
(higher values) 

t

QC _

LU QJ QClay

Organic 

carbon

TIME

Figure 20. Plot from Birkeland (1974) that shows hypothetical 

variation in clay, organic carbon, and carbonate values in 

soils through time.

old range from the 30,000-year-old soils, nor is it easy to 

differentiate soils that range in age between 60,000 and 

200,000 years. Of the properties studied, the Al2O3 +Fe2O3/ 

SiO2 ratio shows the clearest trend and may prove to be the 

most useful indicator for differentiating soils of this age. But 

many more soils developed in sediments 60,000 to 200,000 

years old are needed if we expect to separate that time period 

into smaller units.

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, National Center, MS 926, Reston, VA 22092, and 

R.A. Daniels and Klaus Flach of the USDA 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 for the assistance of field personnel of the Soil Conservation Service in sampling the study profiles.

REFERENCES CITED

Barnheisel, R.I., and Rich, C.I., 1966, Preferential hydroxyaluminum interlayering in montmorillonite and vermiculite: 

Soil Science Society of America Proceeding, v. 30. p. 35- 

39.

Birkeland, P.W., 1974, Pedology, weathering and geomorphological research: Oxford University Press, New York, N.Y., 

285 p.

Bruce, R.R., and Whisler, F.D., 1973, Infiltration of water into 

layered field soils, in Hodas, A., and others, eds., Physical 

aspects of soil waters and salts in ecosystems, SpringerVerlag, New York, p. 77-90.

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

fluvial terraces and scarps along the Rappahannock River, 

Virginia: Earth Science Processes and Landforms, v. 8, 

p. 201-212.

Daniels, R.B., and Gamble, E.E., 1978, Relations between 

stratigraphy, geomorphology, and soils in Coastal Plain areas 

of southeastern USA: Geoderma, v. 21, p. 1-65.

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, p. 98-105.

Douglas, L.A., 1977, Vermiculites, in Dixon, J.B., and Weed, 

S.B., eds.. Minerals in soil environments: Soil Science Society of America, Madison, Wisconsin, p. 258-292.

Flanagan, F.J., 1976, Descriptions and analyses of eight new 

USGS rock standards: U.S. Geological Survey Professional 

Paper 840. 192 p.

Follmer, L.T., 1978, The Sangamon soil in its type area-a review, 

in Mahaney, W.C., ed.. Quaternary soils, Geological Abstracts Ltd.: Norwich, p. 125-165.

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. 329-334.

Hack, J.T., 1955, Geology of the Brandywine area and origin of 

the upland of southern Maryland: U.S. Geological Survey 

Professional Paper 267-A, 43 p.

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.

Harden. J.W., and Marchand, D.E., 1977, The soil chronosequence of the Merced River area, in Singer M.H., ed., Soil 

development, geomorphology and Cenozoic history of the 

northeastern San Joaquin Valley and adjacent area, California: Guidebook for the Joint Field Session of the American 

Society of Agronomy, Soil Science Society of America, and 

Geological Society of America, Chapter VI, p. 22-38.

Karanthanasis, A.D., Adams, Fred, and Hajek, B.F., 1983, 

Stability relationships in kaolinite, gibbsite, and Alhydroxyinterlayered vermiculite soil systems: Soil Science 

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

Lewis, G.C., Fossberg, M.A., Falen, A.L., and Miller, B.J., 

1984, Identification of loess by particle size distribution 

using the Coulter Counter TAII: Soil Science, v. 137, 

p. 172-176.

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

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

geochronology with lithostratigraphy, biostratigraphy, uranium-series coral dating, and magnetostratigraphy in the Atlantic Coastal Plain of the southeastern United States: Quaternary Research, v. 18, p. 337-359.

McFadden, L.O., Tinsley, J.C., and Bull, W.B., 1982, Late Quaternary pedogenesis and alluvial chronologies of the Los Angeles Basin and San Gabriel Mountains areas, southern California, in Tinsley, J.C., ed., Guidebook for the 78th Annual 

Meeting of the Cordilleran Section of the Geological Society 

of America, Anaheim, California, April 19-21, p. 1-27.

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

Upper Cenozoic deposits in the southern Delmarva Peninsula, Virginia and Maryland: U.S. Geological Survey Professional Paper 1067-G, 60 p.

Mixon, R.B., Szabo, B.J., and Owens, J.P., 1982, 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, 41 p.

Age Relations between Soils and Geology 17
Newell, W.L., 1985, Architecture of the Rappahannock Estuary 

neotectonics in Virginia, in Morisawa, M., and Hack, J.T., 

eds., Tectonic Geomorphology, proceedings volume of the 

Fifteenth Annual Geomorphology Symposia Series, held at 

Binghamton, N.Y., September 28-29, 1984: Alien and Unwin.

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

the 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

PRich, C.I., 1968, Hydroxy interlayers in expansable layer silicates: Clays and Clay Minerals, v. 16, p. 15-30.

Ruhe, R.V., 1969, Quaternary landscapes in Iowa: Iowa University Press, Ames, Iowa, 255 p.

Sayin, Mahmut, and Jackson, M.L., 1973, Scanning electron microscopy of cherts in relation to the oxygen isotopic variation 

of soil quartz: Clays and Clay Minerals, v. 23, p. 365-368.

Simonson, R.W., 1978, A multiple process model of soil genesis, 

in Mahaney, W.C., ed., Quaternary soils, Geological Abstracts Limited: Norwich, p. 1-26.

 1982, Loess in soils of Delaware, Maryland and Northeastern Virginia: Soil Science, v. 133, p. 167-178.

Soil Survey Staff, 1951, Soil Survey Manual, U.S. Department of 

Agriculture, Bureau of Plant Industry, Soils, and Agricultural Engineering Handbook No. 18: U.S. Government Printing Office, Washington, D.C., 503 p.

 1972, Soil Survey investigations report no. 1: Soil Survey 

laboratory methods and procedures for collecting samples: 

USDA, Soil Conservation Service, U.S. Government Printing Office, Washington, D.C, 63 p.

 1975, Soil taxonomy: USDA Soil Conservation Service,

Agriculture Handbook No. 436, U.S. Government Printing 

Office, Washington, D.C. 754 p.

Thorp, J., and Smith, G.D., 1949, Higher categories of soil classification: Soil Science, v. 67, p. 117-126.

18 Pedologic Studies in the Eastern United States
Tables 1-9

Age Relations between Soils and Geology 19
Table 1. Analytical methods and units of expression for 

analyses conducted at the Soil Conservation Service, National Soil Survey Laboratory, Lincoln, Nebraska

Analysis Method code 1 Unit of expression

Particle size ---------- 3AI weight percent <2 mm

material 

Organic carbon ------- 6A1C weight percent <2 mm

material 

Dithionite-citrate ------ 6C2A weight percent <2 mm

material 

Iron ----------------- 6C2B weight percent <2 mm

material 

Aluminum ----------- 6G7A weight percent <2 mm

material 

Manganese ----------- 6D2A weight percent <2 mm

material 

Bulk density ---------- 4A1D g/cm3 <2 mm material

COLE2 -------------- 4DI cm/cm whole soil

15-bar tension -------- 4B2A weight percent <2 mm

material 

WRD3 -------------- 4CI cm/cm whole soil

Extractable bases ------ 5B5A meq/100 g <2 mm

material 

CEC

Sum of cations ---- 5A3A meq/100 g <2 mm

material 

NH4OAC -------- 5A8B meq/100 g <2 mm

material 

Al+bases4 ------- 5A3B meq/IOOg<2mm

material 

Base saturation

Sum of cations - - - - 5C3 percent

NH4OAC -------- 5C1 percent

PH

CaCI2 ----------- 8C1E negative log 10

H2O ------------ 8C1A negative log 10

'Method codes from Soil Survey Staff (1972)

Coefficient of linear extensibility

3Water-retention difference

4Aluminum precipitates from solution at pH 4.5 to 4.8. For pH 2:5,

extractable aluminum is not measured.

20 Pedologtc Studies in the Eastern United States
Table 2/4. Description of physical characteristics of soil horizons at site 1, Eastern Neck Island, 28,000 years B.P. 

[Eastern Neck Island is on the west side of the Delmarva Peninsula, 7 km north of U.S. Highway 50 bridge in Kent County, Maryland (fig. 1). The parent 

material is quartzose sand and silt of the Kent Island Formation. Surface elevations on Eastern Neck Island range from 3 to 7 m. Our study site on the 

island is the only study locality without a detailed pedon description. Vegetation at the site is dominantly grass with a mixed hardwood forest only a few 

meters distant; the pit was approximately 18 m from the shore (39°59'30" N. lat, 75°59'15" W. long, 6 m MSL elevation, Langford Creek 7 1/2 min. 

topographic quadrangle). The amount of aerosol contribution, if any, at this locality is undetermined, but a loess cap is indicated by textural analysis (Foss 

and others, 1978) and mineralogy. Further investigations are in progress. Only a general profile description was made at this locality, but it agrees with 

the mapped series]

Depth 

(cm)

0 13 -----

nil31 43 -----

43 69 -----

69 92 -----

92+-------

0 25 -----

OC f^\

61 97 -----

Q7 1 *Ci

Horizon

A 1

A9

DO 1

DOT

TJT

----- C

... . . An /\p 

tj') 1 1

----- B22g 

----- C2 ^&

Moist color1

10YR5/1 

10YR5/1 

10YR6/4 

10YR5/6 

10YR6/4 

10YR5/6

Typical pedon

10YR4/3 

10YR5/6 

10YR6/4 

10YR6/4

Texture2

si

si 

sil 

si

s 

s

of Woodstown

si 

1 

si 

Is

Structure3 Clay skins

SG few bridges 

SG 

SG

Imgr 

2msbk 

2mpl-2msbk 

MA

Roots4 Boundary5

mf 

ff as 

ff

mf as 

mf cw 

ff cw

'Color: Munsell notation

2Texture: l=loam, sil^silty loam, sl=sandy loam, ls=loamy sand, s=sand, g=gravel

Structure: l=weak, 2=moderate, m=medium, gr=granular, sbk=subangular blocky, pl=platy, SG=single grain, MA=massive

4Roots: ff=few fine, mf=many fine

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

Table 26. Textural analyses of soil horizons at site 1, Eastern Neck Island

[<, less than; F, fine; C, coarse; VF, very fine; VC, very coarse; M, medium; TR, trace; grain sizes in millimeters]

Total Silt Sand

Depth 

(cm)

0-13 -

13-30 -

30-43 -

43-69 -

69-91 -

92+ --

Horizon

--- Al

--- A2

--- B21

--- B22

--- B3

--- C

Clay 

<.002

5.8

5.3

4.4

6.0

1.6

10.5

Silt 

.002-.05

32.5

34.2

34.9

28.4

12.1

27.5

Sand 

.05-2

61.7

60.5

60.7

65.6

86.3

62.0

F 

.002-.02

15.4

16.8

17.8

14.1

2.8

7.7

C

.02-.05

17.1

17.4

17.1

14.3

9.3

19.8

VF 

.05-.10

13.9

24.8

15.1

17.6

20.8

18.4

F 

.10-.25

29.5

28.4

30.8

32.8

44.2

28.7

M 

.25-.50

15.4

15.1

13.4

13.8

19.6

13.8

C 

.5-1

1.8

2.0

1.3

1.4

1.6

1.1

VC

1-2

0.1

.2

.1

PR

.1

TR

Age Relations between Soils and Geology 21
Table 2C Weight percent of oxides in soil horizons at site 1, Eastern Neck Island

Horizon, depth (cm)

Oxide

SiO, ------------------------

A1,O, -----------------------

Fe2O3 -----------------------

PaO

K

/~l

TiO2 ------------------------

P

r\

MnO ------------------------

Total ----------------------

Fe^Oj+Al^OySiO-, ------------

A2 

13-30

-------------90.48

------------- 4.81

------------- 1.19

............. 0.19

89

---.--..-...- .75

no

-...-...-.... .03

.--.--..-...-98.4

............. 6.6

B21 

30-43

91.94 

4.67 

1.15 

0.18 

.84 

.68 

.08 

.02

99.6 

6.3

B22 

43-69

92.63 

4.67 

1.42 

0.14 

.54 

.55 

.06 

.01

100.0 

6.6

B3 1 

69-91

90.00 

3.40 

0.65 

.20 

.80 

.66 

.08 

.02

95.8 

4.6

C 1

91 +

89.20 

5.30 

1.43 

0.20 

.80 

.66 

.08 

.02

97.7 

7.5

'Samples mixed with standard basalt to lower the SiO2 concentration

Table 2D. Analyses of extractable Fe, Al, oxalates, and pH of soil horizons at site 1, Eastern Neck Island 

[TR means trace; no entry means not analyzed]

Depth

(cm)

0 13 -----

13 30 -----

30 43 ------

43 6 ------.

69 92 -----

Cn i

Horizon

A 1

A 9

m i

RT>

B1

------ C

Fe

0.4

.4

.4

.6

.3

0

Dithionite-citrate

Extractable 

Al 

(weight percent)

0.2

.2

.1

.1

TR

0.1

Oxalates 

(weight percent)

0.13

.09

.11

Pi

CaCI 2 

(.01 M) 

1:2

4 5

4.5

4.6

4.7

4.8

5.1

H

H2 0 

1:1

5.0

5.0

5.2

5.3

5 4

5.6

Table 3/4. Description of physical characteristics of soil horizons at site 2, Joynes Neck

[The Joynes Neck soil is developed on a gently sloping, moderately dissected plane interpreted to be a part of the shallow shelf immediately adjacent to 

shore during Nassawadox time 60,000-125,000 years B.P. (fig. 1). The study site is located 12.3 km northeast of Accomack in Accomack County, Va. 

(37°50' N. lat, 75°31' W. long, 5 m MSL elevation, Bloxom 7 1/2 min. topographic quadrangle). The texture of the sediments in the upper 200 cm at 

Joynes Neck is similar to those at Oyster, which are considered to be equivalent in age. The parent material at Joynes Neck is 6 m of interbedded gravelly 

and very coarse pebbly clean quartz sand grading upward into medium- to fine-grained quartz sand in the upper 2 m]

Depth

(cm)

O TO

28 45 -

45 67 -

f~] O/i

86-106

106-122 

122 146

1 A £ 1 OO

1 88 9O9

202 235

235 ?45

Horizon

----- Ap An

mi t

T3TH

RO^t

----- B24t

----- B25t 

----- Cl

----- C2

----- B'h

. ... nc3

... . HC4

Moist color1

10YR4/3

7.5YR4/4

7.5YR4/4

7

C"VD C !£.

1 <VD/i/C

7.5YR5/6

1 <VR^/8

i nvD c /^

i nvD f* if*

10YR5/4

10YR5/4

Texture2

fsl

si

1

1

1

si 

Is

s 

Is

Is

Structure3

Imgr

Irshlf lUsUK

Imsbk

Imsbk

Imsbk 

Imsbk

GA"1

GA"1

OA"1

OA"1

few

few

few

Clay skins

, thin, discontinuous

, patchy

Roots4

cf

cf

fvf

fvf

fvf

Boundary5

cs

5

'Color: Munsell notation

2Texture: l=loam, fsl=fine sandy loam, sl=sandy loam, ls=loamy sand, s=sand, g=gravel

3Structure: l=weak, 2=moderate, m=medium, c=coarse, gr=granular, sbk=subangular blocky, p=platy, SG=single grain

4Roots: ff=few fine, mf=many fine, cf=common fine, fvf=few very fine

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

22 Pedologic Studies in the Eastern United States
Table 36. Textural Analyses of soil horizons at site 2, Joynes Neck 

[Sampled as: fine-loamy, mixed, thermic Typic Hapludult; <, less than; F, fine; 

 , not detected; grain sizes in millimeters]

C, coarse; VF, very fine; VC, very coarse; M, medium;

Depth 

(cm)

0-28 -

28-45 -

45-67 -

67-86 -

86-106

106-122

122-146

146-188

188-202

202-235

235-245

Horizon

--- Ap

--- B21t

--- B22t

--- B23t

--- B24t

--- B25t

--- Cl

--- C2

--- B'h

- - - IIC3

- - - IIC4

Clay 

<.002

8.6

15.9

17.1

17.5

16.3

12.1

6.4

2.4

2.0

0.4

Total

Silt 

.002-.05

31.2

38.9

40.1

40.3

35.3

15.4

4.3

3.4

1.1

0.7

1.0

Sand 

.05-2

60.2

45.2

42.8

42.2

48.4

72.5

89.3

94.2

96.9

98.9

99.0

Clay

F 

<.0002

2.0

5.7

5.3

3.7

5.7

5.3

2.0

0.4

Sil

F 

.002-.02

22.9

29.8

30.9

29.7

25.6

12.1

3.2

2.4

0.4

.4

.4

t

C 

.02-.05

8.3

9.1

9.2

10.6

9.7

3.3

1.1

1.0

0.7

.3

.6

VF 

.05-. 10

2.9

2.3

2.2

2.1

2.4

3.4

5.9

3.7

2.7

9.1

1.2

S,

F 

.10-.25

21.6

15.4

14.6

14.3

16.7

25.3

31.3

24.0

44.2

57.5

8.9

and

M 

.25-.50

28.0

20.1

19.2

19.4

21.9

33.7

38.4

44.2

41.0

21.3

20.0

C VC 

.5-1 1-2

7.1 0.6

6.1 1.3

5.8 1.0

5.6 0.8

6.4 1.0

7.8 2.3

10.5 3.2

17.9 4.4

8.0 1.0

6.0 5.0

35.3 33.6

Table 3C. Weight percent of oxides in soil horizons at site 2, loynes Neck 

[TR means trace]

Horizon, depth (cm)

Oxide

SiO, ------------

A1 7 6, -----------

C^Q 3

K

/~i

TiO2 ------------

P o

MnO ------------

Total ----------

Fe2O3 +Al2O3/SiO2

Ap 

0-28

--87.04

 - 5 47

-- 1.79

-- 0.36

-- 1.09

S7

- .13

055

% Q

- 8.3

B21t 

28-45

82.81 

7.75 

2.94 

0.25 

1.21 

.97 

.039 

.099

96.1

12.9

B22t 

45-67

82.10 

9.14 

2.77 

0.28 

1.07 

.87 

.091 

.080

96.4 

14.5

B23t 

67-86

82.16 

8.26 

3.24 

0.25 

1.32 

1.01 

.046 

.051

96.3 

14.0

B24t 

86-106

82.46 

7.88 

3.44 

0.25 

1.29 

1.00 

.039 

.039

96.4

13.7

B25t 

106-122

87.40 

5.79 

2.87 

0.26 

.98 

1.10 

.034 

.046

98.48 

9.9

C1 

122-146

93.92 

3.75 

1.78 

0.24 

.70 

1.24 

.068 

.039

101.7 

5.9

C2 

146-188

95.97 

2.15 

1.05 

0.18 

.59 

1.14 

.032 

.036

101.1 

3.3

B'h 

188-202

93.75 

3.82 

0.35 

.33 

1.09 

.39 

.016 

.020

99.8

4.5

IIC3 

202-235

92.37 

3.56 

0.12 

.39 

1.18 

0.31 

TR 

TR

97.9 

4.0

IIC4 

235-245

97.32 

2.07 

0.27 

.28 

.88 

.15 

TR 

TR

101.0

2.3

Table 3D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 2, Joynes Neck 

[TR means trace; * means estimated; means not detected]

Depth

(cm)

n os

28 45 ----

45 67 ----

f^-l Or

86 106 ---

1 C\£. 1 O^>

122-146 ---

1 A £* 1 OO

i ss ono

202 235 ---

235 245 ---

Horizon

Ap An

m 1 1

DTH

DTJt

--- B24t

RO^t

--- Cl

--- C2

--- B'h

--- IIC3

. . . nc4

Fe

0.6

1.1

1.2

1.2

1.2

1.1

.5

.2

.2

.1

.2

Dithionite-citrate

Extractable

Al

(weight percent)

0.2

.3

.3

.2

.2

.2

.1

TR

.2

.1

.1

Mn

TR

0.1

TD

TR

TD

TR

TD

TD

TD

TD

TD

(weight percent)

0.12

.15

.10

Ratio

CEC

0.53

OS

OS

.30

.32

.30

23

.21

.40

.25

clay

15 bar

0.47

.41

.39

.40

.41

.44

.44

54

.90

~> on

Bulk density

1/3 bar

1.65

1 /iO

1.48

1.61

1.72

1.67

1.50

1.60*

1.70*

1.70*

1.70*

Age Relations between Soils and Geology 23
Table 3f. Analyses of extractable bases, extractable Al, cation exchange capacity (CEC), Al saturation, and pH for soil horizons

at site 2, Joynes Neck

[ means not detected; no entry means not analyzed; TR means trace]

Depth

(cm)

0-28 ---

28-45 ---

45-67 ---

67-86 - - -

86-106 --

106-122 --

122-146 --

146-188 --

188-202 --

202-235 --

235-245 --

NH4 OAC

extractable bases

Horizon

Ap

B21t

B22t

B23t

B24t

B25t

Cl

C2

B'h

IIC3

IIC4

Ca

0.6

1.3

2.1

2.5

2.8

2.1

.9

.4

.3

.1

.1

Mg

0.3

.3

.4

.6

.8

.5

.2

.1

TR

TR

TR

Na

TR

TR

TR

K

0.2

.3

.4

.3

.2

.1

TR

TR

Acidity

6.9

6.1

4.9

4.3

4.7

4.1

2.2

1.3

3.4

2.4

1.5

Extractable Al

0.7

1.0

.4

.3

.2

.2

.2

.1

.2

.1

TR

Sum

cats

8.0

8.0

7.8

7.7

8.5

6.8

3.3

1.8

3.7

2.5

1.6

CEC

NH4 OAC

4.6

4.5

4.8

5.2

5.2

3.6

1.5

0.5

.8

.1

.1

pH

bases+AI

1.8

2.9

3.3

3.7

4.0

2.9

1.3

0.6

.5

.2

Al saturation

39

34

12

8

5

7

15

17

40

50

CaCI 2

(.01 M)

1:2

4.5

4.5

4.8

5.0

5.1

4.9

4.8

4.8

5.1

5.1

5.1

H 2O

1:1

4.9

4.9

5.3

5.4

5.5

5.3

5.2

5.2

5.3

5.4

5.4

Table 4/4. Description of physical characteristics of soil horizons at site 3, Oyster

[The study site at Oyster (fig. 1) is located 9.6 km south of Eastville, Northampton County, Va. (37°17' N. lat, 75°56' W. long, 10 m MSL elevation, 

Cheriton 7 1/2 min. topographic quadrangle). The soil at Oyster is developed in cross-bedded quartz barrier sands and gravels associated with a Nassawodox 

age (60,000-125,000 years B.P.) barrier. The solum and weathering profile are exposed in an abandoned quarry just north of Cobb Mill Creek]

Depth 

(cm)

n 07

27 50 ----

50 70 ----

70 117 ---

m i ~\i

132 147 ---

147 175 -- 

175 215 ---

Horizon

/\p An

m 1 1

RT)t

mi*

--- IIB24t

TTRO^t

TTD1

--- IIC

Moist color 1

10YR4/3 

7.5YR5/6 

7.5YR5/6 

7.5YR5/6 

7.5YR5/8 

7.5YR5/8 

10YR5/6 

10YR8/3

Texture2

si 

1 

1 

1 

si 

si 

Is 

s

Structure 3

Ifgr 

Imsbk 

1ms bk 

Icsbk 

Icsbk 

Icsbk 

SG 

SG

Clay skins

few, thin, patchy 

few, thin, patchy 

few, thin, pathcy

Roots4

ff 

fvf 

fvf 

fvf

Boundary5

as

gs 

gs 

gs 

gs 

cs

'Color: Munsell notation

2Texture: l=loam, sl=sandy loam, ls=loamy sand, s=sand, g=gravel

3Structure: l = weak, 2=moderate, m=medium, gr=granular, sbk=subangular blocky, p=platy, SG=single grain

4Roots: ff=few fine, mf=many fine, fvf=few very fine

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

Table 46. Textural analyses of soil horizons at site 3,Oyster 

[Sampled as: fine-loamy, mixed, thermic Typic Hapludult; <, less than; 

 , not detected; grain sizes in millimeters]

F, fine; C, coarse; VF, very fine; VC, very coarse; M, medium;

Depth

(cm)

0-27 ---

27-50 ---

50-70 ---

70-117 --

117-132 --

132-147 --

147-175 --

175-215 --

Horizon

Ap

B21t

B22t

B23t

IIB24t

IIB25t

IIB3

IIC

Clay 

<.002

5.3

17.1

22.1

18.8

7.3

5.2

1.6

0.8

Total

Silt 

.002-.05

25.2

25.3

23.4

23.1

4.8

3.5

1.4

0.5

Sand 

.05-2

69.5

57.6

54.5

58.1

87.9

91.3

97.0

98.7

Clay

F 

<.0002

2.4

7.7

11.1

8.2

2.4

2.0

0.8

Silt

F 

.002-.02

13.8

16.3

16.0

14.7

2.4

2.0

1.2

0.4

C 

.02-.05

11.4

9.0

7.4

8.4

2.4

1.5

0.2

.1

VF 

.05-.10

4.2

3.1

2.7

2.9

2.9

3.8

3.5

7.2

Sand

F 

.10-.25

22.5

20.1

17.8

18.5

19.6

26.4

36.3

43.4

M 

.25-.50

28.0

23.3

23.0

23.8

27.6

24.2

33.4

33.5

C

.5-1

11.3

9.6

9.6

10.8

18.0

18.8

16.3

10.1

VC 

1-2

3.5

1.5

1.4

2.1

19.8

18.1

7.5

4.5

24 Pedologic Studies in the Eastern United States
Table 4C. Weight percent of oxides in soil horizons at site 3, Oyster 

[TR means trace]

Horizon, depth (cm)

Oxide

SiO2 --------

Fe203 -------

PaO

K O

TiO2 -------- 

Po2(J5 -------- 

MnO --------

Total ------

Ap

0-27

-------- 93.67

 3 00

0 81

-------- .31

QC

.-.--_--. 55

-------- .10

ro

......... 100.2

>iO2 ---- 4.9

B21t 

27-50

84.91 

8.11 

2.28 

0.28 

1.05 

.64 

.027 

.026

97.3 

12.2

B22t 

50-70

77.31 

10.47 

3.53 

0.28 

1.03 

.62 

.05 

.02

93.3 

18.1

B23t 

70-1 1 7

86.25 

7.45 

3.26 

0.23 

1.11 

0.61 

0.039 

0.023

99.0 

12.4

IIB24t 

117-132

92.22 

4.97 

1.08 

0.27 

.84 

.55 

.016 

.024

99.9 

6.6

B25t 

132-147

90.17 

6.19 

0.61 

.30 

.91 

.28 

.031 

.017

98.5 

7.5

IIB3

147-175

95.45 

3.33 

0.02 

.24 

.97 

.11 

TR 

TR

100.1 

3.5

IIC

175-215

88.95 

4.17 

0.01 

.35 

.96 

.19 

TR 

TR

94.6

4.7

Table 4D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 3, Oyster 

[TR means trace; * means estimated; means not detected]

Depth

(cm)

0 27 ----

27 50 ----

50 70 ----

70 117 ---

117 132 ---

132 147 ---

147 175 ---

175 215 ---

Horizon

- - An /\p

RO 1 1

ROOt

Ro^t

--- IIB24t

TTRTCf

IID1

--- IIC

Fe

0.4

1.2

1 Q

1.6

.6

.5

.1

.1

Dithionite-citrate

Extractable 

Al Mn

(weight percent)

0.1

"> TP

1 TP

 3 Tp

1

\

.1

Tp

Oxalates

(weight percent)

0.07

.13

.17

.04

CEC

0.47

.27

.29

32

25

.21

.19

TP

Ratio clay

15 bar

0.49

.39

.40

.42

.42

.48

1 25

1 ^8

Bulk density

1/3 bar

1 0-3

1.79

1.57

1.67

1.80*

1 S 1

1.80*

1.80*

Table 4f. Analyses of extractable bases, extractable Al, cation exchange capacity (CEC), Al saturation, and pH for soil horizons

at site 3, Oyster

[ means not detected; TR means trace]

Depth

(cm)

0-27 --

27-50 --

50-70 --

70-117 -

117-132 -

132-147 -

147-175 -

175-215 -

NH4 OAC

extractable bases

Horizon

-Ap

-B21t

-B22t

-B23t

- IIB24t

- IIB25t

- IIB3

-IIC

Ca

1.7

1.9

2.7

2.6

1.1

0.8

.4

.6

Mg

0.7

.7

1.1

1.1

.5

.4

.2

.1

Na K

 0.4

 0.4

 0.4

TR 0.1

 0.1

 0.1

 TR

 TR

PH

Acidity Al

2.4

3.5

5.5 0.3

5.9

3.0

2.4

0.2

.8

Sum cats

5.2

6.5

9.7

9.7

4.7

3.7

0.8

1.5

«C

NH4 OAC bases +AI saturation

2.5

4.7

6.4 4.5 7

6.0

1.8

1.1

0.3

TR

CaCI 2

(.01 M)

1:2

5.8

5.4

5.0

5.0

5.1

5.2

5.4

5.4

H 2O

1:1

6.2

6.0

5.4

5.6

5.6

5.7

5.8

5.9

Age Relations between Soils and Geology 25
Table 5/4. Description of physical characteristics of soil horizons at site 4, Nelsonia

[The soil developed in medium to coarse barrier sands of the Omar Formation, 140,000-220,000 years in age. The site is 1.6 km south-southwest of 

Nelsonia near the junction of County Rd. 681 and U.S. Highway 13 (37°46' N. lat, 75°36' W. long, 15 m MSL elevation, Bloxom 7 1/2 min. topographic 

quadrangle) (fig. 1). It is possible that the Nelsonia site is on the rim of a Carolina Bay, which would make the land surface somewhat younger than that 

of the stratigraphically younger Nassawadox beds that also have well developed bays. The water table was intercepted at 167 cm]

Depth

(cm)

A 1 T

12 22 -

22 40 -

40 63 -

63 79 -

79 95 -

95-121

121-130

130-150 

150 159

159 169

Horizon

An

A 19

R"71 1

RT)t

DTJt

D7 1

-----B32A'2

-----B'21hir

-----B'22hir 

-----B'23h

-----B'24h

Moist color 1

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

^VR'V)

Texture2

fsl

fsl

1

1

si

si

Ifs

Ifs

s 

Is

Is

Structure3 Clay skins

Imgr 

Imsbk

Imsbk

Imsbk few, thin, discontinuous

Imsbk

Imsbk few, thin, discontinuous

GA"1

MA

MA 

MA ivl/\

MA

Roots4

cfm

££ ***

ffm

ffm

ff

ff

ff

ff

Boundary5

a5

&s

t> s

cs

'Color: Munsell notation

2Texture: l=loam, sl=sandy loam, fsl=fine sandy loam, ls=loamy sand, s=sand, g-gravel

3Structure: l=weak, 2=moderate, m=medium, gr=granular, sbk=subangular blocky, p=platy, SG=single grain, MA=massive

4Roots: ff=few fine, mf=many fine, cfm=common fine and medium, ffm=few fine and medium

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

Table 5B. Textural analyses of soil horizons at site 4, Nelsonia

[Sampled as: fine-loamy, mixed, thermic Typic Hapludult; <, less than; F, fine; C, coarse; VF, very fine; VC, very coarse; M, medium; TR, trace;

 , not detected; grain sizes in millimeters]

Depth 

(cm)

0-12 ---

12-22 ---

22-40 ---

40-63 ---

63-79 ---

79-95 ---

95-121 --

121-130 --

130-150 --

150-159 --

159-169 --

Horizon

Ap

A12

B21t

B22t

B23t

B31

B32A'2

B'21hir

B'22hir

B'23h

B'24h

Table 5C. Weight 

[ means not detected;

Oxide

SiO, -----

Al,6, -----

CaO 3

K n

Tib, ------

P

r\

MnO -----

Total

Fe 2O3 +Al2O3/SiO2 --

Total Clay Silt

Clay Silt Sand F F 

<.002 .002-.05 .05-2 <.0002 .002-.02

6.8 

8.2

22.9

23.4

13.4

6.4

3.6

3.3

0.8

.8

.4

26.9 

31.9

38.9

39.4

23.6

10.7

6.5

4.8

4.2

1.3

2.4

percent of oxides 

TR means trace]

Ap 

0-12

86.27 

4.15 

1.11 

0.34 

.91 

.57 

.06 

.03

93.7 

6.1

A12 

12-22

88.66 

5.28 

1.58 

0.22 

1.02 

.67 

.02 

.03

97.5 

7.7

66.3 

59.9

38.2

37.2

63.0

82.9

89.9

91.9

95.0

97.9

97.2

in soil horizons

B21t B22t 

22-40 40-63

80.66 78.42 

9.42 10.43 

3.70 4.21 

0.20 0.16 

1.30 1.39 

.81 .87 

.04 .054 

.03 .036

96.2 95.6 

16.3 18.7

0.9

2.5

9.4

9.8

4.9

1.2

.8

1.2

.8

 -

at site 4,

B23t 

63-79

85.49 

6.41 

2.42 

0.14 

.94 

.66 

.032 

.029

96.1 

10.3

18.7 

22.5

29.5

28.7

17.0

7.2

5.2

3.3

2.9

0.8

1.2

Nelsonia

Horizon,

B31

79-95

94.91 

3.38 

1.05 

0.14 

.61 

.52 

.073 

.017

100.7

4.7

Sand

C

.02-.05

8.2 

9.4

9.4

10.7

6.6

3.5

1.3

1.5

1.3

0.5

1.2

depth (cm)

B32A'2 

95-121

100.04 

2.13 

0.33 

.14 

.62 

.31 

.01

103.6

2.5

VF 

.05-.10

2.8 

2.4

1.4

1.4

2.2

2.7

2.4

4.6

8.0

4.3

3.4

B'21hir 

121-130

91.06 

3.64 

0.89 

.21 

.75 

.40 

.015 

.014

97.0 

5.0

F 

.10-.25

25.9

23.2

14.8

14.7

24.9

34.1

41.5

46.7

38.8

34.0

41.5

B'22hir 

130-150

93.17 

3.27 

0.33 

.22 

.77 

.35 

TR 

TR

98.1 

3.9

M 

.25-.50

32.9 

29.4

19.1

18.6

31.9

40.4

42.3

38.3

43.6

49.4

48.4

B'23h 

150-159

97.52 

1.81 

0.002 

.18 

.72 

.24 

TR 

TR

100.5 

1.9

C VC

.5-1 1-2

4.5 0.2 

4.5 .4

2.8 .1

2.5 TR

3.9 .1

5.3 .4

3.4 .3

2.2 .1

4.3 .3

8.3 1.9

3.3 .6

B'24h 

159-169

98.10 

1.90 

TR 

0.18 

.63 

.13 

TR 

TR

100.9 

1.8
Table 5D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 4, Nelsonia 

[TR means trace; means not detected; * means estimated]

Depth 

(cm)

0-12 ----

12 22 ----

22-40 ----

40 63 ----

63-79 ----

79 95 ----

95 121 ---

121 130 ---

130-150 ---

150 159 ---

159 169 ---

Horizon

--- An /\p

... A19

T3T1 *

T3T)f

noit

TJ-JI

... Ftt?A'2

--- B'21hir

--- B'22hir

--- B'23h

--- B'24h

Fe

0.5 

0.6 

1.5 

1.7 

1.0 

0.5 

.2 

.6 

.3 

.1 

.1

Dithionite-citrate

Extractable 

Al 

(weight percent)

0.2 

.2 

.3 

.3 

.2 

.1 

.1 

.3 

.4 

.1 

.1

Mn Oxalates 

(weight percent)

TR

TR 0.13 

TR .23 

TR 

TR .07 

TR 

TR 

TR

TR

Ratio clay

CEC

1.63 

0.57 

.32 

.30 

.30 

.30 

.25 

.70 

3.25 

.38 

1.75

15 bar

1.13 

0.50 

.39 

.40 

.39 

.41 

.39 

1.00 

4.13 

1.00 

2.25

Bulk density 

1/3 bar

1.60* 

1.60* 

1.50* 

1.53 

1.50* 

1.56 

1.60* 

1.60* 

1.55 

1.60* 

1.60*

Table 5f. Analyses of extractable bases, extractable Al, cation exchange capacity (CEC), Al saturation, and pH for soil horizons at site 4, Nelsonia 

[ means not detected; TR means trace]

pH

Depth

(cm)

0-12 -

12-22 -

22-40 -

40-63 -

63-79 -

79-95 -

95-121

121-130

130-150

150-159

159-169

NH4 OAC

extractable bases

Horizon

--AP

-- A12

--B21t

--B22t

--B23t

--B31

--B32A'2

--B'21hir

--B'22hir

--B'23h

-- B'24h

Ca

5.6

1.4

1.8

1.2

0.7

.3

.3

.1

Mg

1.5

0.4

.8

.6

.4

.3

.2

TR

Na K

TR 0.7

_ _2

TR .4

TR .2

.1

 TR

.1

 TR

 TR

 

 

Acidity

10.5

6.0

8.1

8.9

5.8

2.9

2.7

7.8

9.8

3.2

4.6

Extractable

Al

0.1

.7

1.7

2.7

1.4

.6

.1

.4

.2

.1

.1

Sum cats

18.3

8.0

11.1

10.9

7.0

3.5

3.3

7.9

8.8

3.2

4.6

CEC

NH4 OAC

11.1

4.7

7.4

7.1

4.0

1.9

0.9

2.3

2.6

.3

.7

bases +AI

7.9

2.7

4.7

4.7

2.6

1.2

0.7

.5

.2

.1

.1

Al

saturation

1

26

36

57

54

50

14

80

100

100

100

CaCI 2

(.01 M)

1:2

4.8

4.6

4.4

4.2

4.2

4.3

4.7

4.9

5.2

5.1

5.1

H 2O

1:1

5.0

5.2

5.1

4.8

4.9

4.9

5.3

5.2

5.3

5.4

5.5

Age Relations between Soils and Geology 27
Table 6/4. Description of physical characteristics of soil horizons at site 5, Persimmon Point

[The Persimmon Point site (fig. 1) is about 16 km west-northwest of the Joynes Neck locality in Accomack County, Va. (37°50' N. lat, 75°32' W. long , 

Bloxom 7 1/2 min. topographic quadrangle). It is 12 m MSL and like the Nelsonia site the soil is developed in the 200,000 year Omar Formation. The 

unweathered parent material of cross-bedded quartz sand and pebble gravel also shows marine influence by the presence of borings, flasier structure, and 

ophiomora burrows. The best exposure of the parent material is in the sand pit about 0.8 km to the east of the study site. The water table was intercepted 

at 290 cm]

Depth

(cm)

0 24 -----

JA. 44 -----

44_65 -----

65 84 -----

84 99 -----

99-122 ----

122-150 ----

150-173 ----

173-200 ----

200-232 ----

Horizon

A.p An

m 1 <- D2.lt

B22t

DTJt DZjt

B24t

IIB25ir

IIB31

IIB32

IIB33

IIC

Moist color 1

10YR4/3

7

C"VD C If.. .JlKj/O

7.5YR5/6

7.5YR5/6

7.5YR5/6

2.5YR3/6

2.5YR3/6

7.5YR5/8

7.5YR5/6

2.5YR7/6

Texture2

fsl

scl

scl

scl

fsl

s

s

s

s

s

Structure3

Imgr

Imsbk

Imsbk

Imsbk

Imsbk

MA

SG

SG

SG

SG

Clay skins

few, thin, patchy

few, thin, patchy

few, thin, patchy

Roots4

fvf

mvf

fvf

fvf

fvf

fvf

fvf

Boundary5

as

cs

cs

aw

cs

cs

cs

cs

cs

'Color: Munsell notation

2Texture: l=loam, sl=sandy loam, fsl=fine sandy loam, scl=sandy clay loam, ls=loamy sand, s=sand, g=gravel

Structure: l=weak, 2=moderate, m=medium, gr=granular, sbk=subangular blocky, p=platy, SG=single grain, MA=massive

4Roots: ff=few fine, mf=many fine, fvf=few very fine, mvf=many very fine

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth, aw=abrupt wavy

Table 65. Textural analyses of soil horizons at site 5, Persimmon Point

[Sampled as: fine-loamy, mixed, thermic Typic Hapludult; <, less than; F, fine; C, coarse; VF, very fine; VC, very coarse; M, medium;

 , not detected; grain sizes in millimeters]

Depth

(cm)

0-24 ---

24-44 ---

44-65 ---

65-84 ---

84-99 ---

99-122 --

122-150 --

150-173 --

173-200 --

200-232 - -

Table 6C.

Horizon

Ap

B21t

B22t

B23t

B24t

IIB25ir

IIB31

IIB32

IIB33

IIC

Weight

Clay

Total

Silt Sand

<.002 .002-.05 .05-2

8.2

21.7

22.1

17.1

15.1

2.4

1.6

0.4

35.8

31.7

30.8

22.4

15.5

2.1

0.6

1.2

.7

.6

56.0

46.6

47.1

60.5

69.4

95.5

97.8

98.8

98.9

99.4

Clay

F

<.0002

2.9

14.3

10.6

9.8

7.3

1.2

0.8

percent of oxides in soil horizons at site

Silt

F

Sand

C

.002-.02 .02-.05

26.2

22.1

22.5

16.3

10.2

1.2

0.4

.4

.7

.4

5, Persimmon

9.6

9.6

8.3

6.1

5.3

0.9

.2

.8

.2

Point

VF F

.05-.10 .10-.25

.5

.3

.3

.4

.6

1.1

0.2

.3

.6

.3

7.8

5.6

6.3

6.8

7.4

15.0

3.4

3.9

2.8

9.0

M

.25-.50

33.2

31.4

32.4

41.1

48.5

73.7

56.4

54.9

31.7

65.3

C VC

.5-1 1-2

12.3 1.2

7.3 1.0

6.3 0.8

9.9 1.3

10.2 1.7

5.3 .4

35.0 2.8

36.8 2.9

43.8 20.0

24.3 .5

[TR means trace]

Oxide

SiO2 -----

A1->O3 ----

Fe2O3 ----

(~"aO

\f r\

TiO2 -----

P205 -----

MnO -----

Total ---

VSi02

Ap

0-24

01 «Q

6

OC

---- 2.24

---- 0.21

oo

---- 1 32

---- 23

---- .067

CO 8

---- 10.4

B21t

24-44

79.90

9.05

4.23

0.16

1.02

1.66

.084

.072

96.2

16.6

B23t

65-84

75.28

7.88

3.79

0.21

.79

1.69

.10

.071

on o

15.5

Horizon,

B24t

84-99

82.44

7.98

3.66

0.21

.64

1.69

.11

.070

96.6

11.7

depth (cm)

IIB25ir

99-122

82.94

4.99

2.52

0.35

.51

.94

.11

.077

92.4

9.1

IIB31

122-150

81.21

2.13

0.50

.12

.57

.13

.041

.016

84.7

3.2

IIB32

183-200

100.42

0.88

.15

.10

.49

.22

TR

.010

102.3

1.0

IIC

200-232

82.01

8.12

3.06

O

^f

1.28

.98

.051

C\f\~) .uo^

95.8

13.6

28 Pedologic Studies in the Eastern United States
Table 6D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 5, Persimmon Point 

[TR means trace; means not detected; * means estimated]

Depth

(cm)

0 94 - - -

'M M

AA M

65 84 ----

84_99 ---.

99 122 ---

m l 50 ---

150-173 ---

17^ 9ftfl

9ftO_9^9

Horizon

--- An J\p

R01 1

tm*

T3T1*

--- B24t

--- HB25ir

jrtjai

TTTJIT

TTT311

... nc

Fe

0.7

1.5

1.5

1.3

1.4

.4

.2

.2

.1

Dithionite-citrate

Extractable 

Al

(weight percent)

0.2

3

3

.3

.3

.4

.2

.1

.1

.1

Mn

T*D

T*D

TT3

T*l?

T*l?

TT3

TT3

TT3

T*l?

Oxalates

(weight percent)

0.07

.21

.17

.34

.50

.01

CEC

0.57

.29

o/;

.27

.27

.50

.63

.50

Ratio clay

15 bar

0.50

.39

37

40

43

00

.69

1.25

Bulk density

1/3 bar

1.69

1.69

1.51

1.50*

1.51

1 87

1.80*

1.80*

1.80*

1.80*

Table 6f. Analyses of extractable bases, extractable Al, cation exchange capacity (CEC), Al saturation, and pH for soil horizons

at site 5, Persimmon Point

[ means not detected; TR means trace]

Depth

(cm)

0-24 -

24-44 -

44-65 -

65-84 -

84-99 -

99-122

122-150

150-173

173-200

200-232

NH4 OAC

pH

extractable bases

Horizon

--Ap

--B21t

- - B22t

--B23t

--B24t

- - IIB25ir

--IIB31

--IIB32

-- IIB33

--IIC

Ca

0.6

0.8

1.1

1.6

1.5

.3

.4

.2

.2

.1

Mg

0.2

0.4

0.5

0.5

0.4

TR

TR

TR

TR

Na K

 0.3

.4

.4

.4

.4

 TR

 TR

 

 

 

Acidity

7.7

5.4

6.8

4.8

5.3

6.7

3.3

2.3

2.2

0.8

Extractable

Al

1.3

2.4

1.9

0.8

1.0

Sum cats

8.8

10.0

8.8

7.3

7.6

7.0

3.7

2.5

2.4

0.9

CEC

NH4 OAC

4.7

6.2

5.7

4.7

4.0

1.2

1.0

0.2

.2

bases +AI

2.4

4.0

3.9

3.3

3.3

Al

saturation

54

60

49

24

30

CaCI 2

(.01 M)

1:2

4.2

4.1

4.2

4.5

4.5

5.2

5.4

5.4

5.3

5.4

H 2O

1:1

4.5

4.6

4.7

4.9

5.0

5.6

5.8

5.8

5.8

5.8

Table 7/4. Description of physical characteristics of soil horizons at site 6, Morris Bridge

[The Norris Bridge study site (fig. 1) is located near the mouth of the Rappahannock River immediately to the east of Route 3 on the north side of the river 

in Lancaster County, Va. (37°38' N. lat, 76°24' W. long ,12m MSL elevation, Irvington 7 1/2 min. topographic quadrangle). The soil at the Norris Bridge 

locality is developed in massive quartz sand that constitutes the upper 4 m of sediment in a 12-m-thick transgressive marine unit of fossiliferous clay and 

cross-bedded and massive quartz sand. The age and location of this undesignated unit suggest that the surface has been influenced by aeolian processes. 

This is corroborated by the fact that the Omar Formation, the unit to which the Norris Bridge sediments are correlated, is dotted by Carolina Bays]

Depth 

(cm)

0-25 -----

25 34 -----

34 48 -----

48 70 -----

70 96 -----

96-138 ----

138-170 ----

170-200 ----

200-230 ----

Horizon

Ap

A9

in 1 1

B23t

B31

B32

Cl

IIC2

Moist color 1

10YR4/3

10YR4/6

7.5YR5/6

5YR5/6

5YR5/6

7.5YR5/6

7.5YR5/6

10YR5/8

10YR5/8

Texture2

Is

si

si

scl

Is

s

s

s

s

Structure3 Clay skins

Ifgr

1m and csbk few, thin, patchy

Icsbk few bridges

SG

SG

SG

SG

Roots4

ffm

ff

ff

ff

ff

Boundary5

as

cs

gs

gs

gs

'Color: Munsell notation

2Texture: l=loam, sl=sandy loam, ls=loamy sand, scl=sand clay loam, s=sand, g=gravel

Structure: l=weak, 2=moderate, m=medium, f=fine, c=coarse, gr=granular, sbk=subangular blocky, p=platy, SG=single grain

4Roots: ff=few fine, mf=many fine, ffm=few fine and medium

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

Age Relations between Soils and Geology 29
Table IB. Textural analyses of soil horizons at site 6, Morris Bridge

[Sampled as: fine-loamy, mixed, thermic Typic Hapludult; <, less than; F, fine; C, coarse; VF, very fine; VC, very coarse; M, medium; TR, trace;

 , not detected; grain sizes in millimeters]

Depth 

(cm)

0-25 -

25-34 -

34-48 -

48-70 -

70-96 -

96-138

138-170

170-200

200-230

 Ap 

---A2

---B21t

---B22t

---B23t

---B31

---B32

---Cl

---IIC2

Clay 

<.002

6.9 

8.9

15.3

17.8

10.5

7.2

5.6

4.3

2.7

Total

Silt 

.002-.05

12.3 

18.8

19.8

17.5

5.2

2.9

0.3

TR

TR

Sand 

.05-2

80.8

72.3

64.9

64.7

84.3

89.9

94.1

95.7

97.3

Clay

F 

<.0002

1.6

2.0

5.7

6.1

6.4

3.6

2.0

Sil

F 

.002-.02

8.1 

13.7

14.9

12.1

2.4

2.0

 

TR

TR

t

C 

.02-.05

4.2 

5.1

3.9

5.4

2.8

0.9

.3

TR

TR

VF 

.05-.10

10.4 

6.6

1.6

5.5

7.4

8.5

1.8

9.0

5.1

Sa

F 

.10-.25

40.1

32.7

34.9

30.4

40.7

44.5

55.2

48.5

14.1

nd

M 

.25-.50

24.9 

26.7

24.2

23.9

29.6

30.8

28.4

28.5

14.9

C

.5-1

4.3 

5.4

3.9

4.3

5.5

5.0

6.0

7.3

23.8

VC 

1-2

1.1 

0.9

.3

.6

1.1

1.1

2.7

2.4

39.4

Table 7C. Weight percent of oxides in soil horizons at site 6, Morris Bridge

Oxide

SiO^ ----------------

Al-,0, ---------------

Fe2O3 ---------------

Pa<~l

K n

TiO - - -

P o

MriO ----------------

Total --------------

Fe2O3 +Al2O3/SiO2 ----

Ap 

0-25

---- 93.01

---- 2.60

---- 1 52

---- 0.13

---- .24

"78

---- .057

---- .15

no <

---- 4.4

A2 

25-34

91.52 

3.71 

2.23 

0.12 

.24 

.77 

.048 

.14

98.8 

6.5

B21t 

34-48

87.34 

5.71 

2.51 

0.10 

.23 

.76 

.065 

.14

96.9 

9.4

B22t 

48-70

87.61 

5.51 

3.49 

0.13 

.26 

.55 

.06 

.16

97.8 

10.3

Horizon,

B23t 

70-96

92.02 

3.42 

2.52 

0.14 

.49 

.51 

.127 

.33

99.6 

6.5

depth (cm)

B31 

96-138

95.01

2.43 

2.10 

0.15 

.43 

.57 

.083 

.29

101.06

4.8

B32 

138-170

93.98 

1.95 

2.93 

0.10

.24 

.55 

.042 

.17

100.0

5.2

C1

170-200

100.00 

0.86 

1.01 

.09 

.19 

.66 

.029 

.14

103.0 

1.9

IIC2 

200-230

97.53 

1.98 

1.02 

0.08 

.19 

.50 

.024 

.13

101.5 

3.1

Table 7D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 6, Morris Bridge 

[TR means trace; * means estimated; means not detected]

Depth

(cm)

0-25

25-34 

34-48

48 70

70-96 

96-138 

138-170

17ft 9OO

900 9 3ft

Horizon

........ A2

rni *

........ B23t 

....... B31 

....... B32 

 - Cl

.

Fe

0.4

.6 

1.0

1.3

.8 

.6 

.5 

.4

.4

Dithionite-citrate

Extractable 

Al

(weight percent)

0.1

.1

.2

.2

.1 

.1 

.1 

.1

.1

Mn Oxalates

(weight percent)

TT?

TR 0.03

TR (V\

T*D no

.08

CEC

O i£.

.27 

^fi

.29

.25 

.25 

.23

o/;

33

Ratio clay

15 bar

0 33

.31

32

.35

.33 

.32 

.32 

.30

3

T<£

Bulk density

1/3 bar

1.71

1.82 

1.71

I

fil

1.63 

1.58 

1.70* 

1.70*

1.70*

30 Pedologic Studies in the Eastern United States
Table 7f. Analyses of extractable bases, extractable Al, cation exchange capacity (CEC), Al saturation, and pH for soil horizons

at site 6, Morris Bridge

[TR means trace; means not detected]

Depth

(cm)

0-25 -

25-34 -

34-48 -

48-70 -

70-96 -

96-138

138-170

170-200

200-230

NH4 OAC 

extractable bases

Horizon

-Ap

-- A2

-- B21t

-- B22t

-- B23t

-- B31

-- B32

-- Cl

-- IIC2

Ca

1.0

0.5

.8

1.6

1.1

1.0

.8

.8

.7

Mg

0.2

.2

.4

.6

.4

.3

.2

.2

.1

Na

TR

TR

TR

TR

K

0.4

.2

.2

.3

Fxtrartahlp

Acidity

2.9

3.1

4.4

5.8

2.8

1.9

1.6

1.2

1.1

Al

0.2

.6

.7

.6

_2

2

TR

Sum cats

4.5

4.0

5.8

8.2

4.3

3.2

2.6

2.2

1.9

CEC

NH4 OAC

2.5

2.4

3.9

5.1

2.6

1.8

1.3

1.1

0.9

bases +AI

1.8

1.5

2.1

3.1

1.7

1.4

Al

saturation

11

40

33

19

12

7

PH

CaCI 2

(.01 M)

1:2

4.6

4.3

4.3

4.4

4.6

4.8

5.0

5.4

5.3

H 2O

1:1

5.1

4.9

4.9

5.0

5.1

5.3

5.5

5.9

5.9

Table 8/4. Description of physical characteristics of soil horizons at site 7, 23 m terrace

[The 23 m terrace locality is on the north side of the Rappahannock River, several hundred meters east of the junction of Routes 601 and 3, Stafford County, 

Va. (38°16' N. lat, 77°24' W. long, 21 m MSL elevation, Fredericksburg 7 1/2 min. topographic quadrangle) (fig. 1). Although parent material was not 

reached, mineralogic evidence from the horizons sampled and the mineralogy and sedimentary structures from nearby outcrops indicate a fluvial origin. 

The alluvium is predominantly a quartz sand containing minor amounts of feldspar and rock fragments ]

Depth

(cm)

0-23 --

23-30 --

30-44 --

44-67 --

67-94 --

94-124 -

124-148 -

148-162 -

Horizon

-- Ap

-- Bl

-- B21t

-- B22t

-- B23t

-- B24t

-- B25t

-- B26t

Moist color1

10YR4/3

10YR4/3

7.5YR4/4

10YR5/6

5YR4/6

5YR5/6

5YR5/6

5YR5/6

Texture2

sil

sil

sil

sicl

sicl

sicl

sicl

sicl

Structure3 Clay skins

If and mgr

Imsbk

Icpr-lf and msbk

Icpr-lf and msbk

lcpr-2msbk

Icpr-lf and msbk

1m and cpr-lf and msbk few, thin, discontinuous

1m and cpr-lf and msbk few, thin, discontinuous

Roots4

mf

cf

cf

cf

ff

ff

ff

Boundary5

as

cs

cs

cs

cs

gs

gs

'Color: Munsell notation

2Texture: l=loam, si=sandy loam, sil = silty loam, sicl=silty clay loam. Is=loamy sand, s=sand, g=gravel

Structure: l=weak, 2=moderate, f=fine, c=coarse, g=granular, sbk=subangular blocky, p=platy, pr=prismatic, SG=single grain

4Roots: ff-few fine, mf=many fine, cf= common fine

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

Table 8B. Textural analyses of soil horizons at site 7, 23 m terrace

[Sampled as: fine-loamy, mixed, thermic Typic Hapludult; <, less than; F, fine; C, course; VF, very fine; VC, very coarse; M, medium; TR, trace;

grain sizes in millimeters]

Depth

(cm)

0-23 

23-30 

30-44 

44-67 

67-94 

94-124 

124-148 

148-162 

Horizon

Ap

Bl

B21t

B22t

B23t

B24t

B25t

B26t

Clay 

< .002

16.0

18.8

26.6

34.5

35.3

34.8

34.5

32.4

Total

Silt 

.002-.05

46.2

46.7

44.2

35.8

28.1

26.9

26.2

24.4

Sand 

.05-2

37.8

34.5

29.2

29.7

36.6

38.3

39.3

43.2

Clay

F 

< .0002

5.3

6.6

11.0

15.2

17.3

18.0

17.3

15.6

Silt

F 

.002-.02

30.4

30.4

30.2

23.0

16.4

15.2

15.6

13.1

C

.02-.05

15.8

16.4

14.0

12.8

11.7

11.7

10.6

11.3

VF 

.05-.10

21.5

19.6

16.4

16.9

21.5

23.3

23.7

25.8

Sand

F 

.10-25

9.8

8.9

8.1

8.0

9.7

10.0

11.2

12.7

M 

.25-.50

5.3

4.8

4.0

3.9

4.1

4.0

3.9

4.4

C 

.5-1

1.0

1.0

0.6

.8

.7

.6

.4

.3

VC 

1-2

0.2

.2

.1

.1

.6

.4

.1

TR

Age Relations between Soils and Geology 31
Table 8C. Weight percent of oxides in soil horizons at site 7, 23 m Rappahannock terrace

Horizon, depth (cm)

Oxide

SiO, --------------

Al^Os -------------

Fe,O3 -------------

PaD

K

f~\

TiO, --------------

P

r\

MnO --------------

Total ------------

Fe->O,+Al->O3/SiO-, --

Ap 

0-23

---75.06

8 89

--- 3.55

--- 0.49

--- 2.20

1 78

--- .30

--- .22

---92.4

---16.5

B1 

23-30

79.09 

10.04 

3.99 

0.49

2.28 

1.84 

.28 

.25

98.3 

17.7

B21t 

30-44

75.82 

11.89 

4.90 

0.42 

2.29 

1.80 

.25 

.17

97.5

22.2

B22t 

44-67

70.78 

14.17 

6.04 

0.45 

2.28 

1.76 

.23 

.12

95.8 

28.6

B23t 

67-94

69.60 

14.66 

6.31 

0.43 

2.33 

1.83 

.23 

.16

95.6 

30.1

B24t 

94-124

67.98 

15.59 

7.15 

0.31 

2.36 

1.88 

.24 

.095

95.6

33.5

B25t 

124-148

67.37 

16.93 

8.22 

0.27 

2.52 

1.89 

.26 

.084

97.5 

37.3

B26t 

148-162

68.18 

16.41 

8.05 

0.28 

2.67 

1.93 

.25 

.083

97.9 

35.9

Table 8D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 7, 23 m terrace 

[TR means trace; means not detected]

Depth

(cm)

0 23 ---

23 30 ---

30 44 ---

44 67 ---

67 94 ---

84 124 --

124 148 --

148 162 --

Horizon

-----ApAn

R91 1

r>')')»

RTlt

--..-B24t

D'Xt

DIAt

Fe

1.4 

1.6 

2.0 

2.6

2.7 

3.1 

3.5 

3.5

Dithionite-citrate

Extractable 

Al 

(weight percent)

0.2

.3 

.3 

.4 

.4 

.4 

.4 

.4

Mn

0.1 

.1 

.1 

.1 

.1 

TR 

TR 

TR

Oxalates 

(weight percent)

0.32 

.30

.31

CEC

0.48 

.41 

.25 

.27 

.23 

.22 

.23 

.23

Ratio clay .. 7 Rnlk

15 bar M

0.46 

.46 

.40 

.41 

.41 

.43 

.46 

.46

density 

3 bar

.44 

.61 

.57 

.50 

.54 

.58 

.47 

.46

Table 8f. Analyses of extractable bases, extractable Al, cation exchange capacity (CEC), and pH for soil horizons at site 7, 23 m

terrace

[TR means trace; means not detected]

Depth

(cm)

0-23 -----

23-30

30-44

44-67 - 

67-94 -

94-124- 

124-148-- 

148-162 

NH4 OAC 

extractable bases

Horizon

Ap

Bl

B21t

B22t

B23t

B24t

B25t

B26t

Ca

6.5

5.7

4.7

6.4

5.7

3.9

2.9

2.1

Mg

1.3

1.2

1.2

1.6

1.4

1.6

2.0

1.8

Na K

0.6

.6

.5

.5

.4

TR .5

.7

.7

PH

Acidity Al

4.3

4.5

4.1

4.7

4.9

5.6

7.4 0.2

7.9 .4

Sum cats

12.7

12.0

10.5

13.2

12.4

11.6

13.0

12.5

CEC

NH4 OAC bases +AI

7.7

7.7

6.7

9.2

8.2

7.5

7.8 5.8

7.5 5.0

CaCI 2 

(.01 M)

1:2

6.1

6.4

6.6

6.6

6.6

6.2

5.2

4.9

H 2O

1:1

6.4

6.8

7.0

7.0

6.9

6.4

5.5

5.2

32 Pedologic Studies in the Eastern United States
Table 9/4. Description of physical characteristics of soil horizons at site 8, 45 m terrace

[The 45 m terrace soil locality (fig. 1) is on the north side of the river, 0.4 km west of Welcome, Va., in King George County (38°11' N. lat, 77°9' W. 

long , 45 m MSL elevation. Port Royal 7 1/2 min. topographic quadrangle). Like the 23 m terrace, the sediments are fluvial in origin and consist of quartz 

sands containing minor amounts of feldspar and rock fragments]

Depth 

(cm) Horizon

0-12 ---- 

12-28 ----

28-43 ----

43-60 ----

60-84 ----

84-112 ---

112-146 ---

146-175 ---

175-213 ---

213-250 ---

Ap

A2

B21t

B22t

B23t

B24t

B25t

B26t

B27t

B28t

Moist color 1 Texture2

10YR4/2 1 

10YR4/3 1

10YR4/3 1

5YR4/6

2.

2.

2.

2.

2.

2.

5YR4/6

5YR4/6

5YR4/6

5YR4/6

5YR4/6

5YR4/6

cl

c

c

c

c

cl

cl

Structure3

Ifgr 

Imsbk-lfgr

Ivf and msbk

Icpr-lmsbk

lcpr-2f and msbk

Icpr-lfsbk

Icpr-lfsbk

Icpr-lfsbk

Icpr-lfsbk

Icpr-lfsbk

Clay skins

few,

few,

few.

few,

thin,

thin.

thin,

thin,

discontinuous

discontinuous

discontinuous

discontinuous

Roots4

mfm 

mfm

mfm

cfm

cfm

cfm

ff

ff

ff

ff

Boundary5

cs 

as

cs

cs

cs

gs

gs

gs

gs

gs

'Color: Munsell notation

2Texture: l=loam, sl=sandy loam, ls=loamy sand, cl=clay loam, c=clay. s=sand, g=gravel

Structure: l=weak, 2=moderate, f=fine, vf=very fine, c=coarse, m=medium, gr=granular, sbk=subangular blocky, pl=platy, pr=prismatic,

SG=single grain

4Roots: ff=few fine, mf=many fine, mfm=many fine and medium, cfm=common fine and medium

5Boundary: cs=clear smooth, as=abrupt smooth, cw=clear wavy, gs=gradual smooth

Table 96. Textural analyses of soil horizons at site 8, 45 m terrace

[Sampled as: fine-loamy, over clayey, mixed, thermic Typic Paleudult; <, less than; F, fine; C, coarse; VF, very fine; VC, very coarse; M, medium;

grain sizes in millimeters]

Depth

(cm)

0-12 --

12-28 --

28-43 --

43-60 --

60-84 --

84-112 -

112-146 -

146-175 -

175-213 -

213-250 -

Table 9C.

[Sampled as

Horizon

-- Ap

-- A2

-- B21t

-- B22t

-- B23t

-- B24t

-- B25t

-- B26t

-- B27t

-- B28t

Weight

Clay

<.002

19.8

23.2

29.4

33.6

37.4

44.0

42.3

47.8

46.4

43.5

Total

Silt Sand

.002-.05 .05-2

44.7

49.0

47.5

42.0

34.5

26.1

25.0

20.7

20.3

16.9

percent of oxides in

: fine-loamy, mixed, thermic Typic

35.5

30.8

23.1

24.4

28.1

29.9

32.7

31.5

33.3

39.6

Clay

F

<.0002

6.5

7.0

11.9

17.6

21.8

26.7

26.3

33.0

31.6

29.1

soil horizons at site

Paleudult]

Silt

F

.002-.02

33.5

37.0

36.0

32.0

26.7

18.9

18.5

15.2

14.0

11.1

C

.02-.05

11.2

12.0

11.5

10.0

7.8

7.2

6.5

5.5

6.3

5.8

VF

.05-.10

7.3

6.5

5.2

5.2

6.1

6.7

6.6

7.6

7.0

6.9

Sand

F

.10-25

7.2

5.7

4.4

4.3

5.0

5.6

5.8

5.9

6.1

6.5

M

.25-.50

9.8

8.4

6.4

6.2

6.2

8.0

7.9

8.7

8.6

10.5

C VC

.5-1 1-2

8.4 2.8

7.9 2.3

5.7 1.4

6.0 2.7

7.3 3.5

7.4 2.2

8.2 4.2

6.6 2.7

7.5 4.1

10.5 5.2

8, 45 m terrace

Horizon, depth (cm)

Oxide

SiO, ----

A1,O3 ---

p O CaQ 3

K

f^\

TiO2 ----

P

/~»

MnO ----

Total

Fe2O3 +Al2O3/SiO2 -

Ap

0-12

- 77.27

- 7.42

- 3.33

- 0.74

- 1.15

- 1.33

- .26

- .20

-91.7

- 13.9

B1

12-28

89 ^7

8.12

3.42

0.30

1 25

1.39

.20

.24

97 5

14.0

B21t

28-43

75 32

11.00

4.94

0

<^s

1.43

1.41

.082

.15

94.6

21.2

B22t

43-60

if. 10

11.79

5.32

0 25

1

0 f

1.36

.072

.16

96.7

22.4

B23t

60-94

74 51

12.62

5.60

O IA

1.13

1.36

.075

.19

95 7

24.5

B24t

84-112 1

72.40

14.42

6

1 o

0.26

.84

1.42

.078

.10

95 6

28.4

B25t

12-146

71.09

13.46

6.05

0.24

sn

1.39

.06

.07

93.2

27.4

B26t

146-175

70.94

14.37

6

10

0 25

.72

1.39

.07

.04

94.2

29.3

B27t

175-213

AC *7O

14.51

6

OO

0.22

.64

1.34

.12

052

OO Q

31.5

B28t

213-250

_,. ,p

13.81

6.29

0.19

1.41

.094

.042

96.1

27.3

Age Relations between Soils and Geology 33
Table 9D. Analyses of extractable Fe, Al, and Mn, oxalates, ratio clay, and bulk density of soil horizons at site 8, 45 m terrace 

[Sampled as: fine-loamy, over clayey, mixed, thermic Typic Paleudult; TR means trace; means not analyzed; * means estimated]

Depth 

(cm)

n 1 9

19 98

28 43 -

43 60 -

60 84 -

84 112 

112 146 

146 175 

175 213 

213 250

Horizon

AAnP

A9

R91 f

R99t

R9"U

...... B24t

RT^t

D O£*

R97t

R98t

Fe

1.5 

1.5

2.3 

2.6 

2.8 

3.2 

3.2 

3.5 

3.3 

3.5

Dithionite-citrate

Extractable 

Al 

(weight percent)

0.2

.2 

.3 

.3 

.3 

.3 

.2 

.2 

.2 

.2

Table 9f. Analyses of extractable bases, cation exchan^ 

[ means not detected]

Depth 

(cm)

0 12 --

1 9 98

28 43 --

43 60 --

60 84 --

84 112 - 

112 146 - 

146 175 - 

175 213 - 

213 250 -

Horizon

...... Ap

A9

R1 1 1

R99t

R9"U

...... B24t

R9*\t

------ B26t

DT7»

RIOt

NH 4

Ca

16.5

4.7 

4.4 

4.9 

5.5 

5.7 

5.6 

6.1 

5.6 

4.7

Mn Oxalates 

(weight percent)

0.1 0.23

.2 

j _

.1 

j _

.1 .23 

TR .26 

TR 

TR 

TR .21

*e capacity (CEC), and pH for

OAC extractable bases

Ratio clay

CEC 15 bar

0.76 0.55 

.43 .41 

.26 .39 

.26 .38 

.23 .27 

.19 .35 

.19 .34 

.19 .34 

.18 .33 

.18 .34

soil horizons at site 8,

CEC

Mg K Acidity Sum cats NH4 OAC

2.4 1 

1.4 0 

1.0 

1.0 

1.1 

1.1 

1.0 

1.2 

1.5 

2.0

.4 15.0 

.6 6.0 12.7 

.5 3.9 9.8 

.5 4.6 11.0 

.4 5.3 12.3 

.2 5.4 12.4 

.2 5.1 11.9 

.2 5.2 12.7 

.2 5.0 12.3 

.2 4.9 11.8

8.6 

7.6 

8.6 

8.6

8.5 

8.2 

8.9 

8.4 

7.8

45 m

CaCI 2 

(.01 M) 

1:2

7.2 

5.6 

5.7 

5.7 

5.7 

5.9 

6.1 

6.2 

6.1 

6.4

Bulk density 

1/3 bar

1.18 

1.67 

1.55 

1.52 

1.49 

1.53 

1.50* 

1.48 

1.50* 

1.53

terrace

pH

H 2O 

1:1

7.5 

6.1 

5.1 

6.1 

6.1 

6.3 

6.5 

6.4 

6.5 

6.5

34 Pedologic Studies in the Eastern United States



LOASi AL HLAir', Mb APb VA U.S.