Holocene Alpine Soils in 

Gneissic Cirque Deposits, 

Colorado Front Range

U.S. GEOLOGICAL SURVEY BULLETIN 1590-E

IM

Chapter E

Holocene Alpine Soils in 

Gneissic Cirque Deposits, 

Colorado Front Range

By P.W. BIRKELAND, R.M. BURKE, and R.R. SHROBA

U.S. GEOLOGICAL SURVEY BULLETIN 1590

SOIL CHRONOSEQUENCES IN THE WESTERN UNITED STATES
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1987

For sale by the

Books and Open-File Reports Section

U.S. Geological Survey

Federal Center, Box 25425

Denver, CO 80225

Library of Congress Cataloging-in-Publication Data

Birkeland, Peter W.

Holocene alpine soils in gneissic cirque deposits,

Colorado Front Range.

(U.S. Geological Survey Bulletin 1590-E)

(Soil chronosequences in the Western United States)

Bibliography

1. Mountain soils Front Range (Colorado and Wyoming).

2. Mountain soils Colorado. 3. Soil formation Front 

Range (Colorado and Wyoming). 4. Soil formation 

Colorado. 5. Soil chronosequences Front Range 

(Colorado and Wyoming). 6. Soil chronosequences 

Colorado. 7. Gneiss Front Range (Colorado and 

Wyoming). 8. Gneiss Colorado. 9. Geology Front 

Range (Colorado and Wyoming). 10. Geology Colorado. 

11. Geology, Stratigraphic Recent. I. Burke, R.M. II. 

Shroba, R.R. III. Title. IV. Series. V. Series: Soil 

chronosequences in the Western United States. 

QE75.B9 No. 1590-E 557.3 s 87-600223 

[S599.C6] [553.6'09788]
FOREWORD

This series of reports, "Soil Chronosequences in the Western United States," 

attempts to integrate studies of different earth-science disciplines, including pedology, 

geomorphology, stratigraphy, and Quaternary geology in general. Each discipline 

provides information important to the others. From geomorphic relations we can 

determine the relative ages of deposits and soils; from stratigraphy we can place age 

constraints on the soils. Field investigations and mineralogic and sedimentologic studies 

provide information on the nature and types of deposits in which soils form. As a result 

of our work, we have estimated rates of soil formation, inferred processes of soil 

formation from trends in soil development with increasing age, and obtained information 

on the types of weathering that occur in various areas. In return, soil development and 

soil genesis have provided data on the age of landforms, the timing and duration of 

sedimentation, and, in some cases, the history of climatic fluctuations.

Between 1978 and 1983, a coordinated and systematic study was conducted on soil 

development in different types of geologic deposits in the Western United States. The 

goals of this project, led by the late D.E. Marchand and subsequently by M.N. Machette, 

were to learn whether rates of chemical, physical, and mineralogic transformations could 

be determined from soil chronosequences; how these rates vary in different mineralogic 

and climatic environments; and how accurately soils can be used for such problems as 

estimating the ages of deposits, periods of landscape stability, and timing of fault 

movements. This series of reports presents data from several soil chronosequences of 

that project.

More than 100 analyses on more than 1,000 samples were performed on soils 

collected in the Western United States. Some results have appeared in various books, 

journals, and maps (for example, Harden and Marchand, 1977, 1980; Burke and Birkeland, 

1979; Dethier and Bethel, 1981; Marchand and Allwardt, 1981; Meixner and Singer, 1981; 

Busacca, 1982; Harden, 1982a,b; Harden and Taylor, 1983; Machette, 1983; Machette and 

Steven, 1983; Busacca and others, 1984; Machette and others, 1984; Reheis, 1984). In the 

reports in this series, the basic field information, geologic background, and analytical 

data are presented for each chronosequence, as well as some results additional to the 

previous publications.

One of the most significant aspects of these chronosequence studies is that in every 

study area, many soil parameters change systematically over time, or with the age of 

deposits. As Deming (1943) emphasized, it is this recurrence of correlation in such 

different conditions that is most significant to geologic and pedologic studies. In 

relatively moist areas, such as coastal and central California, such soil properties as 

percent clay or reddening of soil colors change most systematically over time. In more 

arid regions, such as in the Bighorn basin of Wyoming, calcium carbonate and gypsum 

contents best reflect relative ages of the deposits. A few parameters for example, 

elemental composition of sands or clays appear to be comparable between areas so 

diverse in climatic setting.

Numeric age control has enabled us to estimate rates of soil development. In some 

places, we have been able to compare rates between different areas. For example, in 

central California, rates of clay accumulation were found to. be most rapid during the 

initial stages of soil development; the rates declined with increasing age. The straightest 

lines for regression were on a log-log scale. In coastal California, rates of clay 

accumulation appeared to be much higher than in central California. This difference in 

rates could be due to parent material (the coastal soils that we studied formed on 

reworked shale and sandstone, whereas central California soils were developed in granitic 

alluvium), and (or) the differences in rates could be due to eolian additions of clay. In 

the Bighorn basin of Wyoming, rates of clay accumulation, as well as most other soil 

properties, increased linearly over time, with no apparent decrease in initial rates.

The data we present here suggest many opportunities for further interpretation. 

For example, we may learn how climate, vegetation, and mineralogy affect the rates of 

clay formation or organic-matter accumulation. In some study areas, we present data 

for rare-earth elements, which could be used to examine how each element reacts in 

different weathering environments. These examples are only a fraction of the possible 

future studies that could be conducted on the data presented here.

J.W. Harden 

Editor

CONTENTS

Foreword in 

Abstract El 

Introduction El 

Environmental factors E2

Parent materials E2

Stratigraphic units and geochronology E3

Climate E3

Vegetation E6

Topography E6 

Soil nomenclature E6 

Site selection and sampling procedures E6 

Definitions of the chemical extracts E7

Trends in the field and laboratory data for the soil chronosequence E7 

Post-Gannet Peak soil E7 

Post-Audubon soil E7 

Post-Triple Lakes soil E8 

Post-Satanta Peak soils E8 

Summary of soil-profile characteristics E8 

Comparison with previous work E9 

Trends in soil development indices with time E10

Definitions E10

Results E10 

Conclusions E10 

References cited E13 

Supplementary tables E15

FIGURES

1. Generalized map of study area E2

2. Aerial photograph of Arapaho cirque showing glacial 

and periglacial deposits and study sites E4

3. Plot of profile-development indices versus

approximate age of soil parent materials Ell

4. Plot of color indices versus approximate age of 

soil parent materials E12

TABLES

1. Age control for the glacial and periglacial deposits 

in Arapaho cirque E5

2. Rock-weathering data E5

3. Precipitation and temperature data for station D-l, 

Niwot Ridge, Colorado E6

4. Values for soil-profile and color indices of the soils Ell

5. Regression-equation data for the soil-profile and 

color indices E12

6. Selected statistical measures for the soil-profile and 

color indices for the post-Satanta Peak soils E12

SUPPLEMENTARY TABLES

1. Field descriptions E16

2. Physical properties E17

3. Extractive chemical analyses E18

4. Clay mineralogy E19

5. Total chemical analyses of the soils determined by 

X-ray fluorescence spectroscopy E20

6. Total chemical analyses of the soils determined by instrumental 

neutron activation E21

SOIL CHRONOSEQUENCES IN THE WESTERN UNITED STATES

Holocene Alpine Soils in Gneissic Cirque Deposits, 

Colorado Front Range

By P.W. Birkeland, 1 R.M. Burke, 2 and R.R. Shroba

ABSTRACT

Study of a chronosequence of alpine soils in the 

Colorado Front Range suggests a moderately rapid 

rate of soil formation during the Holocene. Soil parent 

materials in this study include glacial and periglacial 

deposits named Gannett Peak (100-350 yr), Audubon 

(950-2,400 yr), Triple Lakes (3,000-5,200 yr), and 

Satanta Peak (10,000-12,000 yr). Soil morphology and 

chemistry vary in a predictable manner with increasing 

age. The post-Gannett Peak soil has a very thin, 

weakly developed A/Cox profile; the post-Audubon soil 

has a thicker, better developed A/AC/Cox profile; the 

post-Triple Lakes soil has an A/Bw/Cox profile; and 

post-Satanta Peak soils have A/Bw (or Bt)/Cox 

profiles. The two youngest soils are classified as 

Pergelic Cryorthents, the post-Triple Lakes soil is 

either a Pergelic Cryumbrept or Pergelic Cryoboroll. 

The best developed of the post-Satanta Peak soils are 

either Argic Pergelic Cryoborolls or Pergelic 

Cryoboralfs. Airborne dust seems to have had an 

influence on the texture of the surface horizons of the 

post-Triple Lakes and post-Satanta Peak soils, and may 

account for some of the translocated clay in the Bt 

horizons of the post-Satanta Peak soils.

Soil development trends with increasing age 

include increasing amounts of organic carbon, total 

nitrogen, organic-bound phosphorus, clay, extractable 

iron and aluminum, and higher cation exchange 

capacity. Loss of acid-ex tractable calcium-bound 

phosphorus with time suggests a moderately intense 

leaching environment. Calcium is the dominant 

exchangeable cation in all soils, and magnesium is 

present as an exchangeable cation only in the postTriple Lakes and post-Satanta Peak soils. The clay 

mineralogy is difficult to interpret, but the main 

trends with time are the depletion and (or) dilution of 

kaolinite, smectite, and mica, and the formation and 

(or) addition of 1-1.4 nm mixed-layer clays.

Both the field and laboratory data suggest a 

moderately rapid rate of development for soils in the 

alpine of the Colorado Front Range compared to those 

at lower elevations, in spite of the cold climate.

^University of Colorado, Boulder, CO 80309. 

'Humboldt State University, Arcata, CA 95521.

INTRODUCTION

Soil formation is moderately rapid in the higher 

mountain ranges of the western United States, as 

compared to those at lower elevations. One such area 

is the Colorado Front Range (Shroba and Birkeland, 

1983). The main objective of this report is to 

document soil development in the alpine of the 

Colorado Front Range by utilizing soil morphology; 

physical, chemical, and mineralogical data; and various 

soil development indices. Other objectives are (1) to 

compare our age assignments and soil-horizon 

designations with those of previous workers, (2) to 

determine the variability and reproducibility of the 

field and laboratory data for the post-Satanta Peak 

soils, and (3) to evaluate the usefulness of some color 

and soil-profile indices as an indication of soil age in 

an alpine environment.

The soils studied are in Arapaho cirque, a small 

alpine basin in the Indian Peaks area of the Colorado 

Front Range (fig. 1). Arapaho Glacier, the largest 

glacier in Colorado, lies against the headwall in the 

western part of the cirque. The cirque walls are steep 

and rise about 150 to 350 m. The soils have formed 

from Holocene and very latest Pleistocene deposits 

downvalley of the glacier at altitudes between 3,450 

and 3,700 m.

Mahaney (1974) did the initial quantitative work 

on the soils in Arapaho cirque and vicinity. 

Subsequent, detailed soil investigations have been 

conducted in the study area and (or) in nearby cirques 

and valleys by Shroba (1977; Shroba and Birkeland, 

1983), Benedict (1981, 1985), Burns (1980), Dixon 

(1983, 1986), Albino (1984), and Litaor (1987). This 

report provides additional morphological, chemical, 

and mineralogical data for the soils in Arapaho cirque.

Acknowledgments. J.W. Harden helped describe the 

soils in the field. Discussions with numerous people 

have been helpful to us over the many years that we 

have worked in the cirques of the Colorado Front 

Range. These people include J.T. Andrews, J.B. 

Benedict, S.F. Burns, P.E. Carrara, T. Carroll, D.R. 

Crandell, P.T. Davis, W.C. Mahaney, and D.R. 

Mullineaux. R. Kihl of the University of Colorado 

analyzed some of the samples from soil COS. R. Bruce 

and D. Geary assisted in the field, and students in

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado Front Range El
Birkeland's 1982 soils class at the University of 

Colorado helped calculate some of the indices. This 

project was funded by the U.S. Geological Survey Soil 

Correlation and Dating Project, coordinated by the 

late D.E. Marehand and M.N. Machette. We are 

grateful to J.B. Benedict, A.J. Busacca, and P.E. 

Carrara for their thoughtful reviews of this 

manuscript.

ENVIRONMENTAL FACTORS

Pedologists recognize five main factors that 

define the state of the soil system (Jenny, 1980).

These are parent material, time (duration of soil 

development), climate, vegetation, and topography.

Parent Materials

The deposits from which the soils are formed 

include till and rock-glacier debris. These deposits 

have a high boulder content (commonly greater than 50 

percent by volume) and a sandy matrix. Deposits older 

than about 1,000 years usually have a loamy surface 

layer that makes up the upper part of the soil. This 

material has been considered to be eolian in origin 

(Benedict, 1973, 1981; Mahaney, 1974; Birkeland and

105*40' 105*37'30 -

40*03' 

iQ'OQ- -

Triple Y O^"" Lakes ^-^

Goose

Lake

Area of Map 

COLORADO

KILOMETERS

Figure 1. Generalized map of study area. Short dashed lines indicate prominent ridge crests; triangles 

denote peaks. Location of meteorological station D-l is approximate. Grid pattern indicates extent of 

glaciers.

E2 Soil Chronosequences in the Western United States
Shroba, 1974; Shroba, 1977; Burns, 1980; Thorn and 

Darmody, 1980, 1985; Burns and Tonkin, 1982; Shroba 

and Birkeland, 1983; and Litaor, 1987). Dixon (1983, 

1986) also recognized eolian material and suggested 

that at least some of the fine-grained material in the 

upper part of the soil is due to weathering. In some 

places the fine-grained material is gravel free, 

whereas in other places it contains gravel. This gravel 

may have been derived from the underlying material.

The bedrock in Arapaho cirque is Precambrian 

biotite gneiss with lenses of granodiorite. The biotite 

gneiss is composed of biotite, quartz, and plagioclase, 

along with lesser amounts of sillimanite, microcline, 

garnet, and cordierite (Pearson, 1980). The 

granodiorite consists chiefly of plagioclase, quartz, 

biotite, and potassium feldspar (Gable, 1980). We 

assume that the sand and finer fractions of the glacial 

and periglacial deposits, as well as the locally derived 

eolian material, are made up primarily of these 

minerals. However, if the fine-grained surface layers 

have been enriched by eolian silt and clay from distant 

sources, the mineralogy of these fine-grained layers 

may differ from that of the same size fractions of tills 

and rock-glacier deposits that are free of eolian 

sediment.

Stratigraphic Units and Geochronology

The glacial and periglacial deposits in Arapaho 

cirque (fig. 2) are of Holocene and very latest 

Pleistocene age (table 1); however, there are 

differences of opinion regarding the ages of some of 

the older deposits . Benedict (1967, 1968, 1973, and 

1981) and Benedict and Benedict (1984) have done the 

most detailed mapping and dating of the deposits in 

Arapaho cirque. Other important contributions have 

been made by White (1971), Madole (1972), Mahaney 

(1974), Birkeland and Shroba (1974), Reheis (1975), 

Davis and Waterman (1979), Davis and others (1979, 

1984), and Davis (1982). Meierding and Birkeland 

(1980) and Burke and Birkeland (1983) have reviewed 

the previous work in Arapaho cirque and in other 

cirques in the western United States. The ages of the 

deposits in these cirques have been estimated from 

radiocarbon dates and relative-age data such as 

lichenometry, rock weathering, and soils. All of those 

who have worked in Arapaho cirque (cited above) agree 

that the youngest deposit is a till about 100 to 350 

years old, based on historical records and 

lichenometry. It is equivalent to the Gannett Peak 

deposits identified throughout the Rocky Mountains 

(Richmond, 1965), therefore the term Gannett Peak is 

used here rather than Arapaho Peak, a term introduced 

by Benedict (1973). Downvalley from the Gannett 

Peak deposits are rock-glacier deposits that all 

workers agree are of Audubon age. These deposits are 

about 950 to 2,400 years old, based on radiocarbon 

dates and lichenometry. Immediately in front of the

o

°A11 of the Quaternary deposits referred to in 

this report are informal. They are considered 

allostratigraphic units according to the North 

American Commission on Stratigraphic Nomenclature 

(1983).

Audubon deposits is an older rock-glacier deposit 

designated Triple Lakes by Benedict (1973); Triple 

Lakes deposits are probably about 3,000 to 5,200 years 

old, based on radiocarbon dates on younger and older 

deposits and on lichenometry. The only other deposit 

in the cirque of interest in this study is till 

immediately downvalley from the Triple Lakes rockglacier deposit. The age of the till (the Satanta Peak 

till deposits of this report) is not agreed on by all 

workers (Meierding and Birkeland, 1980; Burke and 

Birkeland, 1983). Benedict (1973) relied mainly on 

minimum limiting radiocarbon dates (table 1) to 

suggest that the till is of Triple Lakes age.

There are two reasons for suggesting that the till 

downvalley of the Triple Lakes rock-glacier deposit is 

Satanta Peak rather than Triple Lakes as defined by 

Benedict (1973, 1981). First, five radiocarbon dates on 

detrital organic matter in sediment from a lake behind 

the inner moraine (just west of site CO4 in fig. 2) 

range from 4,730 to 10,410 yr B.P. (see dates of Davis 

in table 1). Considering that none of the dates are on 

basal sediment, the date of 10,410 yr B.P. is 

considered to be a minimum date for the age of the 

till.

The second reason for suggesting a Satanta Peak 

age for the till is based on our rock-weathering 

studies. Of interest here are data for the Triple Lakes 

rock-glacier deposit and the till immediately 

downvalley from it (table 2). The rock-weathering 

data for biotite gneiss are considered to be better 

indicators of differences in weathering than are those 

for granodiorite, because granodiorite is not abundant 

in these deposits and fewer observations were made 

for granodiorite than for gneiss. Although there are 

minor differences in the percentage of both weathered 

and pitted clasts between deposits, pit depths are 

markedly different between the two deposits. We 

attribute these differences in weathering to a 

difference in the ages of the two deposits. We suggest 

that the till is much older than the rock-glacier 

deposit, although some of the apparent differences in 

age could be due in part to the greater length of time 

between the deposition and stabilization of surface 

boulders on the rock-glacier deposit than for those on 

the till.

The best evidence for assessing the age of the 

till downvalley of the Triple Lakes rock-glacier deposit 

is the 10,410 yr B.P. radiocarbon date, mentioned 

above, on lake sediment that postdates the till. 

Because this date is within the estimated age range of 

the Satanta Peak till of Benedict (1985) (10,000-12,000 

yr), we consider the oldest till that we studied to be 

Satanta Peak.

Climate

The climate of Arapaho cirque can be 

approximated by meteorological data from station D-l 

(table 3), which is in the alpine tundra on Niwot Ridge, 

about 4 km to the north (fig. 1). Mean annual 

precipitation for 1965 through 1970 was 102 cm. 

Precipitation from October to May is mostly snow. 

Winter snow is light and dry and can be readily blown 

from ridges, such as the sites selected for this study. 

In contrast, late spring snow is heavier and wetter, and

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado. Front Range E3
much of the moisture released by melting infiltrates 

the soil. The result is that not all of the precipitation 

is distributed evenly on the landscape. The summer 

precipitation in the cirque is not well known. A threeyear study during all or part of the summers of 1971 

through 1973 indicated that precipitation ranged from 

16.5 to 31.6 cm (Johnson, 1979). The study area is 

cold, with a mean annual air temperature of -3.8 °C

and a mean frost-free period of 47 days. The mean 

annual soil temperature at a depth of 30 cm at station 

D-l is -1.1 °C (Marr and others, 1968; Burns, 1980). 

Burns (1980) collected soil-temperature data from 

eight alpine sites on Niwot Ridge east of station D-l; 

the mean annual soil temperature at these sites ranged 

from 0.9 to 3.4 °C. Depending upon local conditions, 

the soil-temperature regime varies from cryic to

1 KILOMETER 

J

Figure 2. Aerial photograph of Arapaho cirque 

showing glacial and periglacial deposits and 

study sites (CO1 to COS). Deposits at and near 

study sites, from youngest to oldest, include 

Gannett Peak till deposits (CO2), Audubon rockglacier deposits (CO1), Triple Lakes rockglacier deposit (COS), and Satanta Peak till 

deposits (CO4, COS, COG, CO7, and COS). 

Lake cored by Davis (1982; Davis and others, 

1984; Davis, 1987) is just west of site CO4. 

Source of aerial photograph is unknown.

E4 Soil Chronosequences in the Western United States
Table 1. Age control for the glacial and periglacial deposits in Arapaho cirque

[Historical records (H) provide only a minimum age for youngest Gannett Peak till deposits (Benedict, 

1968). Lichenometry (L) probably provides only minimum ages, especially for deposits greater than 

about 2,500 yr old (Benedict, 1985, fig. 43). Radiocarbon ages (R), in years before present, for 

Audubon rock-glacier deposits are on organic matter from ablation surfaces in ice of rock glacier; 

those for Satanta Peak till deposits are on organic matter in deposits that are younger than the 

till deposits, therefore, they provide only minimum ages of the till deposits. Estimated age 

ranges are from Benedict (1985)]

Deposit

Benedict (1973)

Arapaho Peak

deposits

Audubon

deposits

Triple Lakes

deposits

Triple Lakes

deposits

This report

Gannett Peak

till deposits

Audubon

rock-glacier

deposits

Triple Lakes

rock-glacier

deposits

Satanta Peak

till deposits

Estimated Age control for deposits

age range , 

in yr B.P. ,

for deposits Dating

in this method

report

100-350 H, L

950-2,400 L

R

R

3,000-5,200 L

10,000-12,000 L

R

R

R

R

R

R

R

R

R

Age

(yr B.P.)

100-250

950-1,850

955195

1, 000190

3,150

2,850

2,3601120

2,5601100

3,8651100

4,4851100

4,7301200

5,4001240

6,430170

9,9151380

10,4101520

References

Benedict (1973)

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Do.

Davis

Do.

Do.

Davis

Do.

(1982)

(1987)

Table 2. Rock-weathering data

[Rock-weathering data features are defined in Burke and Birkeland (1979); underscored data collected by 

R.R. Shroba, other data collected by P.W. Birkeland. Rock-weathering sites are shown on figure 2. Values 

in parentheses refer to number of measurements made. nd, no data]

Site

C02

COl

C03

C04

COS

C06

C07

COS

Percent weathered

Depos It

Biotite Granogneiss diorite

Gannett Peak 0 0

till deposits

Audubon 9 27

rock-glac ier

deposit

Triple Lakes 29 92

rock-glacier

depos it

Satanta Peak 39 86

till deposits,

inner moraine

Satanta Peak nd nd

till depos its ,

outer moraine

Percent pitted

Biotite Granogneiss diorite

0 0

0_

40 22

62 96

84 85

nd nd

Pit depth

Maximum

Biotite Granogneiss diorite

8 0

30 18

*41 32,

34

119 99

142 87,

85

(mm)

Mean

Biotite

gneiss

7

(2)

20

(10)

24

(26)

62

(26)

nd

Granodiorite

0

nd

nd

nd

nd

Two pits that may not be entirely due to weathering were 44 and 73 cm deep.

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado. Front Range E5
Table 3. Precipitation and temperature data for station D-1, Niwot Ridge, Colorado

[Precipitation data are for 1965 through 1970, and air temperature data are for 1952 through 1970 (Barry, 1973). Soil

temperature, taken at 30 cm depth, is mean of weekly maximum and minimum; data are for 1953 through 1958 (Marr and others,

1968) and for 1978, 1979, and part of 1980 (Burns, 1980)] ______

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Year

Mean

precipitation 13.77 9.07 10.54 10.19 6.78 6.99 8.03 5.72 7.16 3.89 11.20 8.76 102.iji3 

(cm)

Air 

temperature

Maximum"^ f -10.1

Vmean -3.8<

Minimum J ^ -16.2

-10.3 -8.2 -3.7 3.1 8.6 12.5 11.3 7.3 1.7 -5.5 -9.1 -.2 

2 -16.2-15.2 -11.1 -4.6 .5 4.4 3.4 -.7 -5.4 -11.6 -15.3 -7.3

Soil 

temperature

-4.4 -.6 3.3 7.2 -1.1

pergelic (Soil Survey Staff, 1975). It is likely that the 

soils in this study have a pergelic soil-temperature 

regime. The soil-temperature data in table 3 suggest 

that the soils are frozen for about seven months a 

year.

Vegetation

Although the vegetation in Arapaho cirque has 

not been mapped or studied in detail, the plants in the 

cirque consist primarily of grasses, herbs, sedges, and 

shrubs (Marr, 1961). Vegetation mapping by 

Komarkova and Webber (1978) on Niwot Ridge suggests 

that the alpine plant community type in well-drained 

areas on the Satanta Peak moraines is alliance 

Kobresia-Caricion rupestris and association EritrichoDryadetum octopetalae. Krummholtz forms of 

Engelmann spruce and subalpine fir are present on the 

distal slope of the outer Satanta Peak moraine; 

however, it is not known if they ever grew at any of 

the study sites on the Satanta Peak moraines.

The proportion of the non-bouldery ground 

surface covered by tundra vegetation varies with the 

age of the deposit. In non-bouldery areas vegetation 

covers about 25 percent or less of the Gannett Peak 

deposits, 25 percent of the Audubon deposits, 75 

percent of the Triple Lakes deposit, and greater than 

75 percent of the Satanta Peak deposits.

Topography

The topographic setting of soil-sampling sites is 

important in chronosequence studies. The desired 

strategy in these studies is to select sites where the 

soil has been forming continuously since the parent 

material was deposited. Ideally, a site should be 

relatively unaffected by erosion or by deposition from 

nearby cirque walls. The sites in this study are on 

relatively flat (<2 percent slopes), broad ridge crests, 

or gentle slopes where erosion is thought to be 

minimal. The sites are located far from cirque walls. 

Because there commonly is a topographic low between 

the site and the nearest cirque wall, deposition of

cirque-wall debris at these sites is unlikely. Eolian 

processes are probably the only mechanism by which 

younger sediment could be transported to the sites 

following the deposition of the till or rock-glacier 

debris. Consequently, the properties of each of the 

soils of this chronosequence should approximate the 

sum total of pedogenesis since the deposition of the 

parent material(s) at each of the sites.

SOIL NOMENCLATURE

The soils in this study were described according 

to the procedures of the Soil Conservation Service 

(Soil Survey Staff, 1975). Soil-horizon nomenclature is 

that of the Soil Conservation Service (Soil Survey 

Staff, 1951; Guthrie and Witty, 1982) combined with 

the C-horizon nomenclature of Birkeland (1984a). For 

C horizons, Cox is slightly oxidized material that does 

not meet the criteria for a cambic (color) B horizon, 

and Cu is unweathered parent material. The 

diagnostic horizons are those defined by the Soil 

Survey Staff (1975) for classification purposes.

The soil names in this report are informal. They 

are formed by adding the prefix "post" to the name for 

the soil parent material. For example, the soil formed 

from till of the Gannett Peak advance is termed the 

post-Gannett Peak soil.

SITE SELECTION AND SAMPLING PROCEDURES

Sites were selected in order to maximize soil 

development. Because so little of the Gannett Peak 

moraine has any alpine plants, the soil was collected 

on the outermost moraine where a small cluster of 

plants was growing. Rock-glacier deposits are 

difficult for soil sampling because stable sites on 

ridges are not common, therefore, there were few 

suitable sites on the Audubon and Triple Lakes rockglacier deposits. In contrast, there are many stable, 

well-vegetated sites on the crests of Satanta Peak 

moraines. We described and sampled several soil 

profiles from the inner and outer Satanta Peak 

moraines in order to determine (1) if there were any

E6 Soil Chronosequences in the Western United States
differences between the soils on the same moraine, (2) 

if there were any pedological differences between 

moraines that correspond with differences in relative 

age, and (3) the reproducibility of the field and 

laboratory data.

Channel samples were collected for each soil 

horizon. The samples were screened in the field; 

material larger than 3 mm in diameter was discarded. 

Prior to laboratory analyses, the samples were passed 

through a 2-mm screen. All of the analyses, as well as 

air-dry color, were performed on material less than 2 

mm in size.

DEFINITIONS OF THE CHEMICAL EXTRACTS

Chemical extracts of iron, aluminum, arid 

phosphorus commonly exhibit systematic pedologic.il 

trends with time (see Birkeland, 1984a, for examples 

and references). The dithionite-citrate method 

determines the amount of free iron and aluminum n 

oxides, hydrous oxides, and organic substances. Most 

of these forms of iron and aluminum do not occur in 

the parent material. Five forms of phosphorus (P) 

were measured; they include: calcium-bound P (Pea) 

in the original minerals, occluded P (Poc) in coatings 

or concretions composed of oxides and hydrous oxides 

of iron and aluminum, non-occluded P (Pnoc) on the 

surfaces of the above oxides and hydrous oxides, 

organic-bound P (Po), and total P (Pt), which is the 

total of the above forms.

TRENDS IN THE FIELD AND LABORATORY DATA 

FOR THE SOIL CHRONOSEQUENCE

Systematic trends in field and laboratory data 

have been observed for most soil chronosequences 

(Birkeland, 1984a). On the basis of data for similar 

soils in areas of similar climate, we hypothesized that 

the soils in the study area would have the following 

trends with time. A horizons would (1) increase in 

thickness, (2) become darker (decrease in color value), 

and (3) differ in percentages of organic carbon (C) and 

nitrogen (N). B horizons would (1) increase in 

thickness and clay content, (2) develop redder hues and 

higher chromas, and (3) possibly have clay films and 

silt caps (coatings composed of silt and clay) on clasts 

(Burns, 1980; Birkeland, 1984a, appendix 1). Cox 

horizons would (1) increase in thickness and (2) develop 

redder hues and higher chromas. The pH values of A 

and B horizons should show an overall decrease with 

time, cation exchange capacity (CEC) should increase 

as the amounts of organic matter and clay content 

increase, and dithionite-extractable iron (Fed) and 

aluminum (Aid) should increase. Phosphorus trends are 

complex because they depend on the degree of 

leaching (Walker and Syers, 1976). In general, with 

sufficient leaching, acid-extractable calcium-bound P 

should decrease; occluded, non-occluded, and organicbound P should increase; and total P should decrease.

The morphology and the physical, chemical, and 

mineralogical properties of the soils in Arapaho cirque 

exhibit numerous significant trends with time (supp. 

tables 1-4, respectively).

POST-GANNETT PEAK SOIL

The post-Gannett Peak soil is an A/Cox profile 

that is only 3 cm thick. This soil has minimal 

development and lacks diagnostic horizons. It is 

classified as a Pergelic Cryorthent (Soil Survey Staff, 

1975). The A horizon is 0.5 cm thick and patchy; the 

Cox horizon is thin and very weakly oxidized. The 

percentages of total sand, silt, and clay suggest a 

change in parent material between the Cox and Cu 

horizons, even though the percentages for the various 

sand-size fractions do not seem to support this 

interpretation. Chemical data indicate considerable 

pedogenesis in the A and Cox horizons relative to the 

Cu horizon4. Specifically, pH has decreased, exchange 

acidity has increased, and there are increases in C, N, 

Fed, Aid, and Po that are more likely to be pedogenic 

than due to variations in the parent material. The 

ranking of the exchangeable cations according to their 

relative abundances is Ca» K > Na, and no Mg. The 

ranking of the clay-mineral peaks according to their 

relative heights is kaolinite =* mica > chlorite 

c* smectite > vermiculite. Kaolinite and mica peaks 

are slightly higher in the A horizon than in the Cu 

horizon.

POST-AUDUBON SOIL

The post-Audubon soil is an A/AC/Cox profile 

that is different from the post-Gannett Peak soil in 

some morphological and chemical characteristics. The 

A and AC horizons have a combined thickness of 27 

cm. Although they are relatively dark, they do not 

meet the color requirements of the mollic or umbric 

epipedon. The Cox horizon is not red enough to qualify 

as a cambic horizon. This soil, therefore, is classified 

as a Pergelic Cryorthent even though it is better 

developed than the post-Gannett Peak soil. Sandfraction data suggest a change in the parent material 

at a depth of 27 cm, but because the total amounts of 

sand, silt, and clay are fairly uniform with depth, and a 

change in parent material was not identified in the 

field, the parent material is considered to be uniform 

throughout the profile. Chemical trends are somewhat 

similar to those for the post-Gannett Peak soil; 

however, some of the chemical data for the postAudubon soil have higher values than those of the postGannett Peak soil or indicate a greater depth of 

chemical alteration. The ranking of the exchangeable 

cations according to their relative abundances are the 

same as for the post-Gannett Peak soil, but the 

amounts are higher. The ranking of the clay-mineral 

peaks according to their relative heights is fairly 

similar in each horizon, with smectite - kaolinite 

> mica > chlorite ^ vermiculite(?). Vermiculite(?) 

occurs in only the A horizon.

The total chemical composition of the soils in 

Arapaho cirque are presented in supplementary tables 

5 and 6. Although these data are not discussed in the 

text, they are included in this report because they 

serve as a chemical data base for the soils, and they 

aid in the interpretation of the extractive chemical 

properties and clay mineralogy of the soils.

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado Front Range E7
POST-TRIPLE LAKES SOIL

The post-Triple Lakes soil has an A/Bw/Cox 

profile. It is different from the post-Audubon soil 

because it has a B horizon. The dark color of the A 

horizon, the content of organic carbon, and a base 

saturation value of 50 percent place it on the border 

between a mollic and umbric epipedon. The B horizon 

is a cambic (color) B with a 10YR hue and chromas of 

3 and 4. This soil is either a Pergelic Cryumbrept or a 

Pergelic Cryoboroll. Parent material layering may 

account for the slight increase in silt and clay in the A 

horizon, or some of these fines could be due to the 

addition of airborne dust. Some of the chemical 

properties, such as pH and Fed, are similar to those for 

the post-Audubon soil but the other properties are 

markedly different. For example, exchange acidity, C, 

N, Aid, and Po are all much higher for the post-Triple 

Lakes soil than for the post-Audubon soil. The data 

for the other P fractions are difficult to interpret, but 

if the values for the post-Gannett Peak soil are 

considered to be an approximation of parent material 

values, then the relatively low values for Pea, except 

for the B horizon, suggest loss of P owing to the 

weathering of apatite. The high value of Pea in the B 

horizon cannot be explained. This is the youngest soil 

to have Mg on the exchange complex, and it is present 

only in the A horizon where the relative abundance 

ranking of the exchangeable cations is Ca» K > Mg 

> Na. Clay mineral peak heights suggest the 

following ranking: smectite ^ kaolinite > mica.

POST-SAT ANT A PEAK SOILS

The post-Satanta Peak soils are characterized by 

an A/Bw (or Bt)/Cox profile, and are the best 

developed soils of the chronosequence. Soils at sites 

CO4 and CO6 have mollic epipedons, those at COS and 

CO7 have umbric epipedons, and the soil at COS has an 

ochric epipedon. B horizons have 10YR and 7.SYR 

hues and chromas of 4 and 5. Three of the five soils 

have Bt horizons that have a sufficient clay increase 

to qualify as argillic horizons (Soil Survey Staff, 

1975). Typically, the argillic horizon is defined on the 

basis of the clay content of the B horizon compared to 

that of the A horizon. In these soils, however, the 

higher silt and clay content of the A horizon relative 

to that of the underlying till suggests the presence of 

some airborne dust in the A horizon. Much of this dust 

may remain in the A horizon, although some of it may 

be translocated into the B horizon, producing more of 

a textural contrast between the B and C horizons than

0 According to the Soil Survey Staff (1975), the B 

horizon meets the color requirement, but is too coarse 

grained to meet the textural requirement for a cambic 

horizon. We recommend waiving the textural 

requirement, because it is too arbitrary for pedologic 

studies; therefore, the B horizon is here considered to 

be a cambic horizon. For comparison, the parent 

material color is considered to be the same as that of 

the Cu horizon of the post-Gannett Peak soil (supp. 

table 1).

between the A and B horizons. In such cases, we use 

the clay content of the B horizon versus that of the C 

horizon to determine whether or not a B horizon is 

argillic6.

The post-Satanta Peak soils belong to several 

different taxonomic units. The soil at COS is a 

Pergelic Cryochrept, the soil at CO7 is a Pergelic 

Cryumbrept, and those with argillic horizons are either 

Argic Pergelic Cryoboroll (CO4) or Pergelic 

Cryoboralf (COS and CO6). The last term is not in Soil 

Taxonomy (Soil Survey Staff, 1975), but it is used here 

to refer to cold soils (mean annual temperatures less 

than 0 °C) with argillic horizons. Parent material 

layering is common in these soils; it is identified by 

the variation in gravel content with depth and by the 

difference in texture of the near-surface horizons. 

Except for pH and Pt, most values for chemical 

properties are commonly as much as 2 times greater 

than those for the post-Triple Lakes soil. In contrast, 

Pea values are much less for the post-Satanta Peak 

soils than they are for the post-Triple Lakes soil, and 

may indicate more intense leaching and (or) prolonged 

leaching of the post-Satanta Peak soils. A large 

proportion of exchangeable Mg exists in these soils, 

especially in the A horizons, where the ranking of 

exchangeable cations is Ca > Mg > K > Na. The 

general trend of the clay mineral peak heights for the 

five soils is kaolinite smectite > mica chlorite 

5: interstratified mica-chlorite. Depth trends are 

difficult to interpret, but smectite is low at depth and 

increases in either the A or B horizon, mica increases 

toward the surface, and kaolinite decreases toward the 

surface. These trends could be due primarily to 

chemical weathering and (or) the addition of airborne 

dust to the near-surface horizons.

SUMMARY OF SOIL-PROFILE CHARACTERISTICS

Several trends with time are readily apparent. 

One is the genetic sequence of soil taxonomic units: 

Pergelic Cryorthent (as much as about 2,000 yr) to 

Pergelic Cryumbrept (about 4,000 yr) to Pergelic 

Cryoboralf (about 10,000-12,000 yr). Color B horizons 

with a 10YR hue, that we designate as cambic 

horizons, form in about 2,000 to 4,000 years. Bt 

horizons with a 10YR or a 7.SYR hue, that we 

designate as argillic horizons, form in about 5,000 to 

12,000 years. Most chemical properties show 

progressive change with time. By about 1,000 to 2,000 

years, pH has reached minimum values common to all 

of the older soils. In contrast, all other chemical 

properties continue to change over the duration of the 

chronosequence. It is not known if the oldest soils are 

in a steady-state condition because data for older soils 

would be needed to make this judgment. In general,

& 

The Bt horizons of the post-Satanta Peak soils

are considered to be argillic horizons, on the basis of 

clay content, even though they lacked clay films when 

examined in the field. Soil thin sections are needed in 

order to definitely determine the presence or absence 

of translocated clay, which is diagnostic of argillic 

horizons.

E8 Soil Chronosequences in the Western United States
CEC increases with time. It tends to increase with 

both organic matter and clay content, although it is 

also dependent in part on the type of clay minerals 

present. The exchangeable cations display the 

following trends: Na and K are present in low amounts 

and show slight increases with time; Ca is the 

dominant cation for soils of all ages, and it increases 

with time; and Mg occurs first in the post-Triple Lakes 

soil where it is restricted to the A horizon, and is 

second to Ca in abundance. These trends could be due 

to soil-forming processes and (or) the addition of 

airborne dust with exchangeable cations dominated by 

Ca and Mg. The amounts of C and N in the A horizons 

increase systematically with time; the C/N ratio of 

the A horizons, however, shows little change with 

time.

Eolian materials are important to some of the 

properties of some of the soils in Arapaho cirque. 

Material collected from melting snow and ice at the 

end of the ablation season is considered to be 

representative of the local eolian materials. One 

sample from Arapaho Glacier has a sand/silt/clay 

percentage ratio of 38/42/20 (Burns, 1980). Other data 

also show that the eolian materials of the region are 

fine grained (Thorn and Darmody, 1980, 1985; Burns, 

1980). In alpine areas, eolian material could 

theoretically either (1) form a discrete surface layer, 

(2) be physically mixed with till or other coarsegrained deposits, or (3) some of it, mainly the silt and 

clay fractions, be translocated to depth in the soil. 

Translocation of eolian material may have produced 

some of the silt caps on clasts in the post-Audubon and 

older soils, and may account for much of the clay 

accumulation in the Bt horizons of some of the postSatanta Peak soils .

Trends in clay mineralogy are difficult to 

interpret because the primary clay minerals can come 

from different sources: the glacial and periglacial 

parent materials or eolian materials. Once deposited, 

the clays may alter to more stable minerals, and some 

or most of them may be translocated downward in the 

profile. The clay mineralogy of the Cu horizon of 

the post-Gannett Peak soil is characterized by 

kaolinite ~ mica > smectite > vermiculite and should 

approximate that of the parent material at depth in all 

of the profiles. The clay mineralogy of the material 

collected on Arapaho Glacier is characterized by mica 

>chlorite > kaolinite ~ smectite and 1-1:4 nm mixedlayer clay (Burns, 1980), and may be similar to that of 

eolian material added to the soils of this study. Trends 

in clay mineralogy over the past 12,000 years seem to 

be the depletion and (or) dilution of kaolinite, 

smectite, and mica, and the formation and (or) 

addition of 1-1.4 nm mixed-layer clay minerals. We 

cannot discriminate between trends due chiefly to 

pedogenic processes and those due chiefly to eolian 

processes.

Not all silt caps are pedologic features, because 

some of them occur in deposits unaffected by 

pedogenesis (P.W. Birkeland, unpub. data, 1984). These 

non-pedogenic silt caps are considered to be a parent 

material property.

COMPARISON WITH PREVIOUS WORK

The data presented in this report compare well 

with those for other soil chronosequence studies in the 

Colorado Front Range and the rest of the Rocky 

Mountain region.

Benedict (1973) did the initial fieldwork on the 

soils in Arapaho cirque. The soil morphological trends 

he described are very similar to those in this report. 

He did not describe a soil on the Triple Lakes rockglacier deposit (soil CO3), and he indicated that there 

was considerable overlap in the properties of the soils 

formed from the type Triple Lakes till (the postSatanta Peak soils of this study) and the type Satanta 

Peak till. Data for the soil formed in the type Satanta 

Peak till at Caribou Lake (fig. 1) are presented in 

Birkeland and Shroba (1974) and Benedict (1985). The 

overlap in morphological properties of the above soils 

can be attributed to soil-forming factors other than 

time, or the type Triple Lakes till (the Satanta Peak 

till deposits of this study) and the type Satanta Peak 

till could be the same age. Mahaney (1974) did the 

first detailed work on the soils in this area of the 

Colorado Front Range that included laboratory 

analyses. In general, we agree with most of Mahaney's 

morphological and analytical data.

Mahaney's work differs from ours in that he (1) 

described a much thicker Cox horizon for the postGannett Peak soil than we did, (2) reported only 10YRhue colors for both the post-Gannett Peak and postAudubon soils, and (3) identified an iron-enriched Bs 

horizon (his Bir horizon) in one of his post-Triple Lakes 

soils. In addition, he used 4 micrometers as the upper 

size limit for the total clay fraction, whereas 2 

micrometers is the accepted size limit between silt 

and clay.

Our main differences with the work of Dixon 

(1983) are that he recognized a B horizon in the postAudubon soil, and the clay percentages that he 

obtained for most of his soils are higher than ours.

Albino (1984) reported trends in soil development 

with time that are similar to those of this study, 

although she recognized B horizons in her post-Gannett 

Peak soil and in one of her post-Audubon soils, and she 

reported Fed values that are higher than those we 

report for our soils.

Shroba (1977; Shroba and Birkeland, 1983) studied 

alpine soils equivalent in age to those in Arapaho 

cirque over a large region of the Rocky Mountains and 

reported findings that are similar to ours. Broad 

similarities are also seen between alpine soils in 

Arapaho cirque and soils of similar ages in the Wind 

River Mountains, Wyoming (Miller and Birkeland, 

1974). We believe that the similarity of soil properties 

reported by different workers throughout the Rocky 

Mountains lends credence to the use of soils as a 

criterion for broad, regional correlations of 

Quaternary deposits.

Trends in the relative abundance of clay minerals 

with time reported in other studies of Holocene soils in 

the region differ somewhat from those of this study. 

Mahaney (1974) reported that illite decreased and 

chlorite, montmorillonite, and mixed-layer illitemontmorillonite increased with time in soils in 

Arapaho cirque. Dixon's (1983, 1986) work in Arapaho 

cirque indicated depletion of kaolinite and the

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado. Front Range E9
alteration of biotite to hydrobiotite, vermiculite, and 

smectite. In a cirque 6 km south of Arapaho cirque, 

Albino (1984) recognized the depletion of mica, 

chlorite, and randomly interstratified mica/smectite, 

and the formation of ordered mica/smectite and 

intergrade chlorite. In the Colorado Rocky Mountains, 

Shroba (1977; Shroba and Birkeland, 1983) described a 

decrease in mica and an increase in mixed-layer clays 

(1-1.8 nm) with time in alpine areas that may have 

never been forested.

TRENDS IN SOIL DEVELOPMENT INDICES WITH 

TIME

Definitions

Soil field descriptions are quite complicated and 

involve many qualitative observations and some 

quantitative measurements. Several indices have been 

devised to integrate the descriptive data for either a 

horizon or an entire profile into a single numerical 

value that serves as a ranking of the degree of 

development of the horizon or profile. Two of the 

better known indices have been developed by Bilzi and 

Ciolkosz (1977) and Harden (1982a; Harden and Taylor, 

1983). Both indices are somewhat similar in that the 

properties of each horizon are compared to those of 

either the C horizon (Bilzi and Ciolkosz, 1977) or the 

parent material (Harden, 1982a). A numerical value is 

assigned based on the difference between two horizons 

or a horizon and the parent material. For both 

methods, a total value can be calculated for each 

horizon; the larger the value, the more the horizon 

differs in most pedological properties from either the 

C horizon or the parent material. One problem with 

each of these methods is that soils commonly develop 

to different depths. The difference in depths alone 

can have a major influence on index values, because 

horizon index values are multiplied by horizon 

thickness.

For this study we have modified each of the 

methods so that they will yield a value more closely 

related to profile development to a uniform depth (see 

discussion in Birkeland, 1984a, and in Harden and 

Taylor, 1983). In order to take into account the fact 

that soils commonly are described to different depths, 

we increased the thickness of the lowest horizon so 

that each profile had the same thickness as the 

thickest soil of the chronosequence, which in this study 

was 85 cm. Although this approach created some 

problems (Birkeland, 1984a), it permitted comparison 

of the soils to a common depth. Higher index values in 

these systems usually correspond to greater soil 

development.

The systematic reddening of soil color with time 

in well-drained soils has also been the basis for other 

development indices. The Munsell color notations can 

be converted to a single index value; three such indices 

are used here to assess soil development. The first is 

the Buntley-Westin (B-W) color index (Buntley and 

Westin, 1965), in which hue is assigned a numerical 

value (7.5YR=4, 10YR=3, 2.5Y=2, 5Y=1) that is 

multiplied by the chroma. The second is the Hurst (H) 

color index (Hurst, 1977), in which hue is assigned a

numerical value (5YR=15, 7.5YR=17.5, 10YR=20, etc.) 

that is multiplied by the fraction formed by the value 

and chroma (value/chroma). The third is rubification, 

one of several properties of the soil development index 

of Harden (1982a), in which the color of each horizon 

is compared with that of the parent material. In this 

system, each shift toward a redder hue and each shift 

toward higher chromas is assigned a value of 10 

points. For all three color indices, we multiplied the 

numerical value for each horizon by horizon thickness, 

once the thickness of the lowest horizon was adjusted 

so that the thickness of all profiles was the same (85 

cm). We then summed the horizon values to yield a 

total value for the soil profile. Both the B-W color 

index and rubification increased with the redder hues 

and higher chromas that accompany greater degree of 

pedogenesis, whereas the H color index decreased.

One problem common to all of these color 

indices is that the effect of eolian parent materials is 

not known. In this report, we considered the colors of 

the eolian parent materials to be similar to those of 

the glacial parent materials, although these colors may 

not be representative of all of the soil parent 

materials. This is especially true if some of the eolian 

parent materials were derived from previously 

weathered deposits.

Results

The point values for each of the index systems 

change in a systematic manner with time (table 4). 

Both of the profile-development indices increase with 

time (fig. 3). Values for both indices define linear 

functions and have similar correlation coefficients 

(table 5). All color indices change with time (fig. 4). 

Both rubification and B-W values define linear 

functions. Rubification has a higher correlation 

coefficient than the B-W index. In contrast, values for 

the H index define a power function with a high, 

negative correlation coefficient. Comparison of the 

standard deviations of the various indices for the postSatanta Peak soils, expressed as a percentage of the 

mean (table 6), indicates that the profile indices have 

less variation than the color indices, and that the 

rubification and H indices have less variation than the 

B-W index.

We calculated the above indices to assess their 

usefulness for the correlation of surficial deposits in 

alpine environments. The results presented in this 

report are encouraging, as are those for the Wind 

River Mountains, Wyoming (fig. 1-10 in Birkeland, 

1984a) and those for part of the Southern Alps, New 

Zealand (Birkeland, 1984b). More work on soil indices 

in different areas is needed in order to further test 

their usefulness.

CONCLUSIONS

One of the goals of soil chronosequence studies is 

to evaluate the usefulness of various soil properties for 

estimating the ages of surficial deposits. The 

discussion in this report pertains to cirque deposits 

above treeline in the Colorado Front Range. Detailed 

field descriptions are essential in soil chronosequence

E10 Soil Chronosequences in the Western United States
studies because field-description data can be used to consistent results. Laboratory data vary in their 

calculate index values that may be useful age usefulness in soil chronosequence studies. In this 

indicators. study, the most useful laboratory data for 

For greater accuracy, color data collected in the differentiating deposits of different ages were particle 

field should be compared with data for the air-dried size, Fed, Aid, Pea, C, and N. 

seived samples, because the latter give the most

Table 4. Values for soil-profile and color indices of the soils

[All values are for 85-cm-thick soil profiles. Soil-profile sites are shown on figure 2. Buntley-Westin and Hurst color 

indices refer to dry colors. nd, not determined]

Profile indices

Site

C02

C01

C03

C04

COS

C06

CO 7

COS

Soil

Post-Gannett 

Peak

Post-Audubon

Post-Triple

Lakes

PostSatanta

Peak

Bilzi-Ciolkosz

0

4

6

8

8

10

10

7

(X100)

.18

.23

.32

'"'I

.54 V X=9.14

.00

.85 J

Harden

0.008

.194

.213

.288 ^1

.367 I ?

.388 [

 403 J

nd 1

Bunt ley-Wes tin

0

4

5

10

17

9

6

4

(X100)

.15

.65

.49

.32 1

.82 > X=9.79

.75

.44 J

Color indices

Hurst

(X1000)

12

4

4

2

2

2

2

3

.59

.83

.09

'"'I

.06 > X=2.53

.66

.64 J

Rubif ication

(XI 000)

0

2

6

8

9

10

7

6

.002

.80

.71

-\

-«l.

.60 >X=8.58

.90

.40 J

No pH data. Because pH is important to the calculation of Harden's profile index, the profile index was not 

determined for this soil.

0.4

x

LU 

Q

Z 

LU

o

cc 0.2

Q.

LU 

Q

cc 

<

1 0.1

EXPLANATION

+ Harden 

 Bilzi-Ciolkosz

4,000 8,000 

APPROXIMATE AGE, IN YEARS

12

X

III 

a

Z 

LU

8 t

O 

cc

Q.

N 

CO 

O

4

N

_J

CO

12,000

Figure 3. Plot of profile-development parent materials used to plot data are as

indices versus approximate age of soil follows: 300 yr for Gannett Peak

parent materials. Trend lines based on deposits; 1,500 yr for Audubon deposits;

regression equations in table 5; data 4,000 yr for the Triple Lakes deposit; and

from supplementary table 1. Ages of soil 11,000 yr for Satanta Peak deposits.

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado^ Front Range Ell
16

12

x

UJ 

Q

Z

DC 

O

o

O

EXPLANATION

 Buntley-Westin 

A Rubification 

+ Hurst 

0 L£_

4,000 8,000 

APPROXIMATE AGE, IN YEARS

12,000

Figure 4. Plot of color indices versus approximate age of soil parent materials. 

Trend lines based on regression equations in table 5; data from supplementary 

table 1. For ages of soil parent materials, see figure 3.

Table 5. Regression-equation data for the soil-profile and color indices

[Regression models used: 1, linear; p, power. X, age of soil parent material 

in years]

Property Model Regression equation Correlation 

(Y) coefficient

Harden index 1 Y = 0.08 + 0.000026 X 0.91

Bilzi-Ciolkosz 1 Y = 2.08 + 0.00065 X .92

index

Buntley-Westia 1 Y = 1 .88 + 0.00073 X .67 

index

Hurst index p log Y = 2.14 - 0.432 log X -.95

rubification 1 Y = 1.62 + 0.00065 X .88

Significance 

level

0.01

.01

.10

.001

.05

Table 6. Selected statistical measures for the soil-profile and color indices 

for the post-Satanta Peak soils

[Individual index values are listed in table 4]

Statistical Profile indices____ _________Color indices__________

measure Bilzi-Ciolkosz Harden Buntley-Westin Hurst Rubification

(X100) (X100) (X1000) (X1000)

Mean 9.14 

Standard deviation 1.11 

Standard deviation .12

as a percentage

of the mean

0.362

.051

.141

9.79

4.98

.51

2.53 

.67 

.26

8.58

1.56

.18

Soil Chronosequences in the Western United States
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Burns, S.F., and Tonkin, P.T., 1982, Soil-geomorphic

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eliminates probe contact: Soil Science Society of 

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 1987, Late Pleistocene age for type Triple Lakes 

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with Programs, v. 19, no. 5, p. 270.

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Guidebook to Holocene deposits in Arapaho 

cirque, Colorado Front Range: American 

Quaternary Association 8th biennial meeting, 

Boulder, Colorado, 28 p.

Davis, P.T., Upson, Susan, and Waterman, S.E., 1979, 

Lacustrine sedimentation variation as an indicator 

of late Holocene climatic fluctuation, Arapaho 

cirque, Colorado Front Range abs. : Geological 

Society of America Abstracts with Programs, v. 

11, no. 7, p. 410.

Davis, P.T., and Waterman, S.E., 1979, New 

radiocarbon ages for type Triple Lakes moraines, 

Arapaho cirque, Colorado Front Range abs. : 

Geological Society of America Abstracts with 

Programs, v. 11, no. 6, p. 270.

Deming, W.E., 1943, Statistical adjustment of data: 

New York, Wiley, 261 p.

Dethier, D.T., and Bethel, John, 1981, Surficial 

deposits along the Cowlitz River near Toledo, 

Lewis County, Washington: U.S. Geological 

Survey Open-File Report 81-1043, 10 p.

Dixon, J.E., 1983, Chemical weathering of late 

Quaternary cirque deposits in the Colorado Front 

Range: Boulder, University of Colorado, Ph.D. 

thesis, 174 p.

___1986, Solute movement on hillslopes in the alpine 

environment of the Colorado Front Range, in 

Abrahams, A.D., ed., Hillslope processes: London, 

George Alien and Unwin, p. 139-159.

Gable, D.J., 1980, The Boulder Creek Batholith, Front 

Range, Colorado: U.S. Geological Survey 

Professional Paper 1101, 88 p.

Guthrie, R.L., and Witty, J.E., 1982, New designations 

for soil horizons and layers and the new Soil 

Survey Manual: Soil Science Society of America 

Journal, v. 46, p. 443-444.

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

development from field descriptions: Examples 

from a chronosequence in central California: 

Geoderma, v. 28, no. 1, p. 1-28.

____1982b, A study of soil development using the 

geochronology of Merced River deposits: 

Berkeley, University of California, Ph.D. thesis, 

237 p. 

in Gneissic Cirque Deposits, Colorado- Front Range E13
Harden, J.W., and Marchand, D.E., 1977, The soil 

chronosequence of the Merced River area, 

California, in Singer, M.J., ed., Soil development, 

geomorphology, and Cenozoic history of the 

northeastern San Joaquin Valley and adjacent 

areas, California, chap. 6 of American Society of 

Agronomy-Soil Science Society of AmericaGeological Society of America, joint field session, 

1977, guidebook: Davis, Calif., American Society 

of Agronomy.

__1980, Quaternary stratigraphy and interpretation of 

soil data from the Auburn, Oroville, and Sonora 

areas along the Foothills fault system, western 

Sierra Nevada, California: U.S. Geological Survey 

Open-File Report 80-30, 57 p.

Harden, J.W., and Taylor, E.M., 1983, A quantitative 

comparison of soil development in four climatic 

regimes: Quaternary Research, v. 20, p. 34Z-359.

Hurst, V.J., 1977, Visual estimation of iron in 

saprolite: Geological Society of America Bulletin, 

v. 88, p. 174-176.

Jenny, H., 1980, The soil resource: New York, 

Springer-Verlag, 377 p.

Johnson, J.B., 1979, Mass balance and aspects of the 

glacier environment, Front Range, Colorado, 

1969-1973: Boulder, University of Colorado, 

Ph.D. thesis, Z87 p.

Komarkova, V., and Webber, P.J., 1978, An alpine 

vegetation map of Niwot Ridge, Colorado: Arctic 

and Alpine Research, v. 10, p. 1-Z9.

Litaor, M.I., 1987, The influence of eolian dust on the 

genesis of alpine soils in the Front Range, 

Colorado: Soil Science Society of America 

Journal, v. 51, no. 1, p. 14Z-147.

Machette, M.N., 1983, Geologic map of the southwest 

quarter of the Beaver quadrangle, Beaver County, 

Utah: U.S. Geological Survey Miscellaneous 

Investigations Series Map 1-1444, scale 1:Z4,000.

Machette, M.N., and Steven, T.A., 1983, Geologic map 

of the northwest quarter of the Beaver 

quadrangle, Beaver County, Utah: U.S. Geological 

Survey Miscellanaeous Investigations Series Map I1445, scale 1:Z4,000.

Machette, M.N., Steven, T.A., Cunningham, C.G., and 

Anderson, J.J., 1984, Geologic map of the Beaver 

quadrangle, Beaver and Piute Counties, Utah: 

U.S. Geological Survey Miscellaneous 

Investigations Series Map I-15ZO, scale 1:50,000.

Madole, R.F., 197Z, Neoglacial facies in the Colorado 

Front Range: Arctic and Alpine Research, v. 4, p. 

119-130.

Mahaney, W.C., 1974, Soil stratigraphy and genesis of 

neoglacial deposits in the Arapaho and Henderson 

cirques, central Colorado Front Range, in 

Mahaney, W.C., ed., Quaternary environments: 

Toronto, Atkinson College/York University 

Geography Monograph No. 5, p. 197-Z40.

Marchand, D.E., and Allwardt, Alan, 1981, Late 

Cenozoic stratigraphic units, northwestern San 

Joaquin Valley, California: U.S. Geological 

Survey Bulletin 1470, 70 p.

Marr, J.W., 1961, Ecosystems of the east slope of the 

Front Range in Colorado: Boulder, University of 

Colorado Studies, Series in Biology, No. 8, 134 p.

Marr, J.W., Johnson, A.W., Osburn, W.S., and Knorr, 

O.A., 1968, Data on mountain environments n. 

Front Range, Colorado, Four climax regions,

E14 Soil Chronosequences in the Western United States

1953-1958: Boulder, University of Colorado 

Studies, Series in Biology, No. 28, 171 p.

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glaciation of Colorado, in Kent, H.C., and Porter, 

K.W., eds., Colorado geology: Denver, Rocky 

Mountain Association of Geologists, p. 165-173.

Meixner, R.E., and Singer, M.J., 1981, Use of field 

morphology rating system to evaluate soil 

formation and discontinuities: Soil Science, 

v. 131, no. 2, p. 114-123.

Miller, C.D., and Birkeland, P.W., 1974, Probable preneoglacial age of the type Temple Lake moraine, 

Wyoming: Discussion and additional relative-age 

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306.

North American Commission on Stratigraphic 

Nomenclature, 1983, North American 

stratigraphic code: American Association of 

Petroleum Geologists Bulletin, v. 67, no. 5, p. 841- 

875.

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Peaks study area, Boulder and Grand Counties, 

Colorado: U.S. Geological Survey Bulletin 1463, 

109 p.

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deposition of debris on Arapaho Glacier, Front 

Range, Colorado: Journal of Glaciology, v. 14, p. 

407-420.

____1984, Chronologic and climatic control on soil 

development, northeastern Bighorn Basin, 

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Colorado, Ph.D. thesis, 293 p.

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eds., The Quaternary of the United States: 

Princeton, N.J., Princeton University Press, p. 

217-230.

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and Central Rocky Mountains: Boulder, 

University of Colorado, Ph.D. thesis, 424 p.

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late-Quaternary soil development in the Rocky 

Mountains and Sierra Nevada of the western 

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1, The Late Pleistocene: Minneapolis, University 

of Minnesota Press, p. 145-156.

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Department of Agriculture Handbook No. 18, 

503 p.

_____1975, Soil taxonomy: U.S. Department of 

Agriculture Handbook No. 436, 754 p.

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eolian sediments in the alpine zone, Colorado 

Front Range: Physical Geography, v. 1, p. 162- 

171.

____1985, Grain-size distribution of the insoluble 

component of contemporary eolian deposits in the 

alpine zone, Front Range Colorado: Arctic and 

Alpine Research, v. 17, p. 433-442.

Walker, T.W., and Syers, J.K., 1976, The fate of 

phosphorus during pedogenesis: Geoderma, v. 15, 

p. 1-19.

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Front Range, 1961 to 1968: Arctic and Alpine 

Research, v. 3, p. 43-64.
SUPPLEMENTARY TABLES
Supplementary table 1.' Field descriptions

[nd, not determined; no, not observed. Analysts: P. Birkeland, R. Burke, and J. Harden]

. Basal Lower 

Site Horizon depth boundary 

(cm)

Color3

Moist Dry

Percentage Consistence

of >2-mm Texture5 Structure6 MoistWeT Roots 1' q Pores films

Gannet Peak till deposits, 0.1-0.35 ka

C02 A

Cox

Cu

0.5

3

18+

a,s

c,w

no

10YR3/2

nd

7.5Y4/1

10YR4/2

2.5Y6/2

7.5Y5.5/1

75

75

75

SL

SL

SL

sg

sg

sg

lo

lo

lo

ss.po

ss,po

ss,po

1 med+ fi

1 fi

no

no

no

no

no

no

no

Audubon rock-glacier deposits, 0.95-2.4 ka

C01 A

AC

Cox

Cox

7

27

45

75+

c,w

c,w

d.nd

no

10YR2/2

10YR4/3

2.5Y4/3

2.5Y4/3

10YR2/2.5

10YR6/3

2.5Y6/2

2.5Y6/2

75

75

75

75

coSL

coSL

coSL

coSL

sg

sg

sg

sg

lo

lo

lo

lo

so.po

so.po

so,po

so,po

3 fi + med

3 fi + med

1 fi

1 fi

no

no

no

no

no

no

no

no

Triple Lakes rock-glacier deposit, 3-5.2 ka

COS A

2A

2Bw

2Cox

12

24

49

58+

c,w

c,w

c,w

no

10YR2/2

10YR2/3

10YR4/4

2.5Y4/1

10YR3.5/2

10YR4/3

10YR5.5/3

2.5Y6/2

nd

75

75

75

coSL

coSL

LcoS

coSL

2 med sbk

1 med sbk

sg

sg

lo

fr

lo

lo

so,po

so,po

so.po

so.po

3 med, 2 fi

3 med, 2 fi

no

no

1 med tub no

1 med tub no

no no

no no

Satanta Peak till deposits, inner moraine, 10-12 ka

C04

C05

A

2Bt

2BC

A

2Bt

2Cox

14

38

62+

13

31

85+

c,w

g,w

no

c,w

c,w

no

10YR3/2

7.5YR3/4-4/5

10YR3.5/4

7.5YR2/2

10YR3/5

10YR3/3

10YR4/2

7.5YR4/4-5/4

10YR5/4

7.5YR3/2

10YR4/5

10YR4/3

10

75

75

25

75

75

fiSL

SL

coSL

coSL

SL

coSL

m, 1 med sbk fr

2 med sbk fr

sg lo

m, 1 med sbk fr

1 med sbk fr

sg lo

so,po

so.po

so.po

so.po

so.po

so,po

3 fi , 2 med, 1 co

2 med

no

3 f i , 2 med

3 med

2 med, 2 fi

1 med .tub no

1 fi tub no

no

1 med tub no

1 med tub no

no

Satanta Peak till deposits, outer moraine, 10-12 ka

C06

CU7

COS

A

2Bt

2Cox

A

2AB

2Bw

2Cox

A

2Bw

2Cox

*Soi 1 -profile

Lowpr hori?or

15

38

80+

11

16

41

80+

9

25

85+

sites are

T hnundarv

C,W

C,W

no

C,W

C,W

C,W

no

c,w

g,w

no

shown on

i <; m'vpn

7.5YR2/2

7.5YR3/4

7.5YR3/4

10YR2/2

10YR2/3

10YR3.5/4

2.5Y3/3

7.5YR2/2

10YR3/4

5Y4.5/3

figure 2.

in twn narts:

7.5YR2/2

7.5YR4.5/4

10YR5/3.5

10YR2/2

10YR3/3

10YR5.5/4

2.5Y5/3

7.5YR3/2

10YR5/4

5Y6/3

: H 1 r1ic;tinr1

10

25

75

10

25

25

50

10

25

75

 .np<;<; n.

L

coSL

COLS

fiSL

SL

SL

SL

L

SL

coSL

ah runt: r. .

m, 2 med sbk

2 med sbk

sg

m, 1 med sbk

1 med sbk

2 med sbk

1 med sbk

2 med sbk

2 med sbk

1 fi abk

. rlpar: a. arad

fr

fr

fr

fr

fr

fr

fr

fr

fr

lo

lual .

so.po

ss.po

so.po

so.po

so.po

ss,po

ss.po

so.po

so,po

so,po

d. diffuse

3 fi + med

no

no

2 med, 1 fi

2 med, 1 fi

2 med, 2 fi

1 fi

2 med, 2 fi

2 med, 2 fi

1 fi

>: 12) tODoaraoh

1 med tub no

1 fi tub no

2 fi tub no

1 med tub no

1 med tub no

1 fi tub no

2 fi tub no

1 med tub no

1 fi tub no

1 fi tub no

v: s. smooth: w.

wa vy.

^Color is the Munsell color of the fraction less than 2 mm in size. 

^Percentage of material larger than 2 mm in size is based on visual estimates.

Texture of the material less than 2 mm in size is based on sieve and pipette analyses: 

gSandy loam; S, sand. 

Except for massive (m) and single grain (sg), structure is given in three parts: (1) grade:

medium; (3) type: sbk, subangular blocky; abk, angular blocky.

Moist consistence is either loose (lo) or friable (fr). Wet consistence is given in two parts: (1) stickiness: so, non-sticky;

sticky; (2) plasticity: po, non-plastic. 

qData for roots are given in two parts: (1) abundance: 1, few; 2, common; 3, many; (2) size: f i, fine; med, medium; co, coarse. 

yOata for pores are given in three parts: (1) abundance: 1, few; 2, common; (2) size: fi, fine; med, medium; (3) shape: tub, tubular.

co, coarse; fi, fine; L, loam; LS, loamy 

1, weak; 2, moderate; (2) size: fi

sand; SL, 

, fine; med, 

ss, slightly

E16 Soil Chronosequences in the Western United States
Supplementary table 2. Physical properties

[na, sample not analyzed; nd, not determined. Analysts: A.. Busacca, P. Janitsky, R 

Meixner under M. Singer, University of California, Davis, and R. Kihl, University of 

Co 1orado]

Basa 

Site Horizon dept 

(cm

C02 A 

Cox 

Cu

C01 A 

AC 

Cox

C03 A 

2A 

2Bw 

2Cox

0.5 

3 

18 +

7 

27 

75

12 

24 

49 

58 +

Percentage of <2

1 Sand 2

h Total vco co med f+vf

Gannett Peak till deposits, 0.1

82.2 19.1 14.6 12.0 36.5 

85.6 37.7 20.3 9.3 18.3 

69.2 19.6 14.1 9.1 26.8

Audubon rock-glacier deposits, 0.

80.7 18.5 14.2 11.1 36.9 

82.6 21.1 18.1 11.8 31.6 

85.0 32.1 18.0 10.2 24.7

Triple Lakes rock-glacier deposit

74.4 14.4 14.8 10.4 34.8 

74.9 14.3 16.4 11.3 32.8 

80.8 20.5 19.7 12.0 28.5 

71.7 13.9 15.8 10.8 31.2

-mm fraction

Silt 3

Total

-0.35 ka

10.9 

8.3 

20.0

95-2.4 ka

11.9 

10.5 

7.8

, 3-5.2 ka

15.0 

15.0 

11.3 

20.4

Satanta Peak till deposits, inner moraine, 10-12

C04 A 

2Bt 

2BC

C05 A 

2Bt 

2Cox

14 

38 

62+

13 

31

85 +

62.2 5.7 6.6 6.0 43.9 

60.1 13.5 12.8 8.4 25.4 

86.7 22.3 16.9 10.0 27.5

61.7 21.5 13.7 7.2 19.3 

63.6 17.3 12.6 8.3 25.4 

75.1 20.9 15.5 10.1 28.6

28.6 

25.8 

6.2

28.8 

26.3 

18.0

Satanta Peak till deposits, outer moraine, 10-12

C06 A 

2Bt 

2Cox

C07 A 

2AB 

2Bw 

2Cox

COS 5 A 

2Bw 

2Cox

*Soi 1 -p rof i 1 e

15 

38 

80 +

11 

16 

41 

80 +

9 

25 

85 +

sites

53.1 17.9 12.6 6.7 16.2 

66.8 17.5 14.5 9.5 25.3 

86.3 21.6 21.3 15.5 27.9

71.5 14.7 14.4 8.2 34.2 

na na na na na 

64.8 13.6 12.6 9.2 29.4 

67.7 15.1 12.6 9.5 30.5

69.2 20.6 18.9 8.3 nd 

74.1 20.0 16.6 10.7 26.8 

74.3 16.5 15.4 10.0 nd

are shown on figure 2.

33.0 

24.1 

10.7

21.7 

na 

25.9 

25.2

22.5 

20.6 

18.4

Clay 4

Total

6.9 

6.1 

10.4

7.4 

6.9 

7.2

10.6 

10.1 

7.9 

7.9

ka

9.2 

14.1 

7.1

9.5 

10.1 

6.9

ka

13.9 

9.1 

3.0

6.8 

na 

9.3 

7.1

8.4 

5.3 

7.4

CO

3.7 

3.5 

4.3

3.0 

3.4 

4.2

3.9 

4.2 

4.5 

4.7

1.6 

4.1 

3.0

1.5 

1.3 

2.3

7.0 

2.2 

1.1

2.0 

na 

3.1 

3.0

0.5 

2.6 

4.0

f

3.2

2.6 

6.1

4.4 

3.5 

3.0

6.7 

5.9 

3.4 

3.2

7.6 

10.0 

4.1

8.0 

8.8 

4.6

6.9 

6.9 

1.9

4.8 

na 

6.2 

4.1

7.9 

2.7 

3.4

: Size ranges of the sand fraction are: total (2-0.05 mm); vco, very coarse (2-1 mm);

co, coarse (1-0.5 mm); med, medium (0.5-0.25 mm); f+vf, fine and very fine (0.25-

0.05 mm).

pi It is 0.05 to 0.002 mm (50 to 2 M m) in size. 

4 Size ranges of the clay fraction are: total (<2 ^m); co, coarse (2-1 ^m); f, fine

(<1 M m).

Analyzed by R. Kihl, University of Colorado.

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado.. Front Range E17
Supplementary table 3. Extractive chemical analyses 1

[na, sample not analyzed; nd, not determined. Analysts: A. Bussacca, P. Janitsky, R. Meixner, under M. Singer, University of Californi

n

Site Horizon

Basal

depth 

(cm)

Percentage of <2-mm

Total Organic 

N C

meq/lOOg soil Percentage of <2-mm

Exchangeable cations Fe^

Na K Ca Mg H CEC

A1 d - PH

1:1H20 1:1KC1

Pt P

Gannet Peak till deposits, 0.1-0.35 ka

C02 A 

Cox 

Cu

C01 A

AC 3 CoxJ

C03 A 

2A 

2Bw 

2Cox

0.5 

3 

18+

7 

27 

75+

12 

24 

49 

58+

0.068 

0.011 

0.010

0.154 

0.039 

0.023

0.398 

0.185 

0.058 

0.021

1.5 

0.12 

0.11

2.07 

0.44 

0.22

5.82 

2.27 

0.48 

0.20

0.010 

0.020 

0.020

0.030 

0.020 

0.001

0.020 

0.020 

0.020 

0.040

0.22 

0.09 

0.36

0.28 

0.13 

0.13

0.73 

0.27 

0.08 

0.11

2.93 0.00 3.11 4.49 0.60 

3.53 0.00 0.94 3.08 0.53 

3.53 0.00 0.82 3.33 0.44

Audubon rock-glacier deposits, 0.

5.15 0.00 5.61 8.66 0.70 

3.23 0.00 6.41 4.49 0.64 

4.34 0.00 1.91 4.41 0.52

Triple Lakes rock-glacier deposit

11.72 0.50 10.26 22.56 0.55 

4.34 0.61 8.36 11.99 0.77 

2.32 0.00 4.79 5.08 0.55 

3.74 0.00 2.45 4.58 0.45

0.068 

0.051 

0.043

,95-2.4 ka

0.125 

0.085 

0.055

, 3-5.2 ka

0.196 

0.211 

0.159 

0.113

Satanta Peak till deposits, inner moraine, 10-12

C04 A 

2Bt 

2BC

C05 A 

2Bt 

2Cox

14 

38 

62+

13 

31 

85+

0.462 

0.190 

0.071

0.878 

0.273 

0.103

7.30 

2.33 

1.01

13.85 

3.61 

1.52

0.040 

0.050 

0.090

0.110 

0.090 

0.090

0.50 

0.22 

0.11

0.77 

0.33 

0.32

9.39 6.47 13.27 29.05 0.63 

8.28 1.82 10.05 17.98 0.89 

3.74 0.70 6.15 8.24 0.71

16.97 3.94 26.99 45.20 0.84 

3.84 0.81 18.06 19.15 1.01 

2.83 0.00 10.42 10.57 0.75

0.225 

0.234 

0.159

0.353 

0.356 

0.176

Satanta Peak till deposits, outer moraine, 10-12

C06 A 

2Bt 

2Cox

C07 A 

2AB 

2Bw 

2Cox

COS A 

 2Bw 

2Cox

15 

38 

80+

11 

16 

41 

80+

9 

25 

85+

0.819 

0.189 

0.041

0.744 

na 

0.138 

0.031

nd 

0.112 

nd

13.34 

2.09 

0.48

12.33 

na 

1.51 

0.34

10.00 

1.44 

0.44

^Chemical analyses were performed on the 

^Soil-profile sites are shown on figure 

^Chemical data are for the combined Cox

0.060 

0.090 

0.050

0.080 

na 

0.080 

0.090

0.060 

0.050 

0.030

less than 

2. 

horizons.

0.32 

0.03 

0.02

0.75 

na 

0.02 

0.02

0.71 

0.06 

0.09

2 mm

21.72 3.63 18.7 43.04 0.75 

2.93 0.00 12.91 13.40 0.72 

1.41 0.00 4.42 3.91 0.51

12.42 2.43 23.17 36.55 0.73 

na na na na na 

2.63 0.00 9.29 10.32 0.86 

1.82 0.00 5.27 4.74 0.54

10.81 2.12 13.87 26.31 1.06 

2.52 0.00 7.76 8.74 0.89 

2.32 0.00 3.98 3.58 0.71

size fraction of the soil samples.

0.374 

0.261 

0.119

0.313 

na 

0.224 

0.166

0.419 

0.220 

0.231

5.4 

5.4 

6.3

5.5 

5.6 

5.6

5.8 

5.5 

5.4 

5.7

ka

5.5 

5.8 

5.6

5.5 

5.0 

5.0

ka

6.0 

5.2 

5.3

5.1 

na 

5.0 

5.3

nd 

5.1 

nd

4.10 

4.37 

4.86

4.20 

4.20 

4.20

4.96 

4.35 

4.16 

4.12

4.77 

4.47 

4.10

4.70 

3.73 

3.69

5.41 

3.91 

4.02

4.31 

na 

3.81 

4.05

nd 

3.89 

nd

208.0 

nd 

181.0 

402.0 

305.0 

239.0 

940.0 

680.0 

420.0 

149.0 

732.0 

533.0 

223.0 

1384.0 1

680.0 

355.0 

1106.0 

417.0 

196.0 

858.0 

na 

280.0 

166.0 

nd 

337.0 

nd 

4The forms of phosphorus are: Pt, total; Pnoc, non-occluded; Poc, occluded; Pea, acid-extractable calcium-bound; Po, organic
Supplementary table 4. Clay mineralogy

[Relative abundances of clay minerals based on peak height: n, none detected; + , minor 

amount; ++, moderate amount; +++, major amount; ++++, dominant amount, na, sample not 

analyzed. Analysts: A. Busacca, P. Janitsky, R. Meixner, under M. Singer, University of 

California, Davis]

,""->"' Basal o o

Site 1 Horizon depth Chlorite Kaolinite Smectite Mica Vermiculite Interstratified 

(cm)

Gannett Peak till deposits, 0.1-0.35 ka

C02 A

Cox

Cu

0.5

3

18+

n

na

n

Audubon rock-glacier deposits, 0.95-2.4 ka

C01 A

AC

Cox

Cox

7 + ++++

27 + +++

47 + +++

75+ + +++

++++ ++ +

++++ ++ n

++++ ++ n

++++ ++ n

n

n

n

n

Triple Lakes rock-glacier deposit, 3-5.2 ka

C03 A

2A

2Bw

2Cox

12 + ++

24 + +++

29 + +++

58+ + ++++

+++ ++ n

+++ ++ n

++++ ++ n

++++ ++ n

n

n

+

n

Satanta Peak till deposits, inner moraine, 10-12 ka

C04

C05

A

2Bt

2BC

A

2Bt

2Cox

14 + ++

38 + +++

62+ + ++

13 + ++

31 + ++

85+ + ++

+++ ++ n

++++ + n

+++ + n

++ ++ n

++ + n

++ + n

n

+

+

n

+

n

Satanta Peak till deposits, outer moraine, 10-12 ka

C06

C07

COS

A

2Bt

2Cox

A and

2AB

2Bw

2Cox

A

2Bw

2Cox

15 + ++

38 + ++

80+ + ++

16 + ++

41 + ++

80+ + ++

9 + ++

25 + ++

85+ + +++

++ + n

++++ + n

++ + n

++ + n

++ + n

+ + n

+++ ++ n

++ + n

+ ++ n

+

+

+

n

+

+

n

+

+

^Soil-profile sites are shown on figure 2.

Vermiculite may be present, but not detectable in some samples; however, most samples 

showed no increase in intensity of the 1-nm peak after saturation with KC1. 

Interstratified clay minerals are chiefly regularly interstratified mica-chlorite; some 

interstratified mica-vermiculite may also be present.

Holocene Alpine Soils in Gneissic Cirque Deposits, Colorado Front Range E19
Supplementary table 5. Total chemical analyses of the soils (less than 0.05 mm fraction) 

determined by X-ray fluorescence spectroscopy

[na, sample not analyzed; nd, not determined, units in weight percent. Analysts: J. Baker, 

J. Taggart, J.S. Wahlberg, U.S. Geological Survey, Menlo Park]

Basal

Site1 Horizon depth Si02 A1 20 3 Fe 2 03 MgO CaO Na 2 0 K2 0 Ti02 P2 0 5 MnO 

(cm)

Gannett Peak till deposits, 0.1-0.35 ka

C02 A 

Cox 

Cu

0.5 

3 

18+

53.40 

na 

51.80

23.60 

na 

26.80

8.850 2.20 

na na 

8.350 3.10

0.650 

na 

0.570

0.90 

na 

0.90

Audubon rock-glacier deposits, 0.95-2.4

C01 A 

AC 

Cox 

Cox

7 

27 

47 

75+

54.40 

53.30 

52.50 

53.20

21.10 

23.80 

26.90 

24.20

Triple Lakes

C03

C04 

C05

C06 

C07

COS

A 

2A 

2Bw 

2Cox

A 

2Bt 

2BC

A 

2Bt 

2Cox

A 

2Bt 

2Cox

A 

2AB 

2Bw 

2Cox

A 

2Bw 

2Cox

12 

24 

49 

58+

14 

38 

62+

13 

31 

85+

15 

38 

80+

11 

16 

41 

80+

9 

25 

85+

na 

50.70 

56.20 

47.00

Satanta

53.40 

55.30 

47.50

na 

46.90 

52.70

Satanta

49.00 

54.60 

na

na 

na 

49.80 

52.60

50.80 

50.20 

51.00

na 

18.90 

20.30 

21.60

Peak till

16.40 

18.00 

21.90

na 

19.00 

27.40

Peak till

11.90 

18.00 

na

na 

na 

22.30 

24.40

12.80 

21.60 

24.80

6.060 1.80 

6.620 2.00 

6.930 2.00 

8.940 2.20

rock-glacier

na na 

5.750 1.80 

6.940 1.90 

8.810 2.20

0.690 

0.590 

0.510 

0.510

deposit

na 

0.690 

0.660 

0.480

0.80 

0.80 

0.80 

0.90

, 3-5.2

na 

0.90 

1.10 

0.80

2.94 

na 

3.83

ka

2.71 

2.90 

3.06 

3.31

ka

na 

2.53 

2.84 

3.19

0.82 

na 

0.90

0.71 

0.71 

0.69 

0.85

na 

0.71 

0.81 

1.11

0.1 

na 

0.1

0.2 

0.2 

0.1 

0.1

na 

0.5 

0.2 

0.2

0.06 

na 

0.09

0.08 

0.10 

0.09 

0.08

na 

0.08 

0.09 

0.05

deposits, inner moraine, 10-12 ka

5.290 1.40 

5.600 1.50 

8.580 2.00

na na 

6.970 1.60 

6.020 2.30

1.060 

0.680 

0.180

na 

0.440 

0.440

1.00 

0.80 

0.70

na 

0.80 

0.80

2.44 

2.35 

2.11

na 

2.54 

3.03

0.64 

0.87 

0.79

na 

0.93 

0.63

0.3 

0.3 

0.2

na 

0.3 

0.1

0.06 

0.03 

0.04

na 

0.04 

0.09

deposits, outer moraine, 10-12 ka

3.880 1.30 

5.250 1.30 

na na

na na 

na na 

8.310 2.00 

8.380 2.40

4.500 1.40 

8.180 1.90 

8.480 2.40

1.320 

0.410 

na

na 

na 

0.390 

0.350

0.960 

0.450 

0.370

1.00 

0.80 

na

na 

na 

0.80 

0.80

1.00 

0.80 

0.80

2.19 

2.32 

na

na 

na 

2.98 

3.57

2.35 

2.63 

3.55

0.61 

0.82 

na

na 

na 

0.85 

0.90

nd 

0.89 

0.94

0.4 

0.2 

na

na 

na 

0.2 

0.1

0.4 

0.2 

0.1

0.05 

0.04 

na

na 

na 

0.04 

0.06

0.05 

0.03 

0.05

Soil-profile sites shown on figure 2.

E20 Soil Chronosequences in the Western United States
Supplementary table 6. Total chemical analyses of the soils (less than 0.05 mm fraction) determined by instrumental 

[na, not analyzed; Na, Fe, and K values in weight percent, all others in part per million. , Analysts: J. Budahn, R. Knight under D.M. McKown, U.S. Geologica

Basal

Site1 Horizon depth Na 

(cm)

Nd Tb Tm Eu 

05*

Ml

i'

n

0°

pw3*

O

9

o'

y

e

w

s

1

F

0

g,

SJ

8

o

i

e?g.

1

Mto

C02 A

Cox

Cu

C01 A

AC

Cox

Cox

COS A

2A

2Bw

2Cox

C04 A

2Bt

2BC

C05 A

2Bt

2Cox

C06 A

2Bt

2Cox

C07 A

2AB

2Bw

2Cox

COS A

2Bw

2Cox

Soil -profile

0.5

3

18+

7

27

47

75+

12

24

49

58+

14

38

62+

13

31

85+

15

38

80+

11

16

41

80+

9

25

85+

sites

0.699

na

0.644

0.681

0.596

0.552

0.541

0.639

0.651

0.725

0.678

0.765

0.626

0.465

0.661

0.554

0.54

0.696

0.651

0.675

0.665

na

0.592

0.675

0.738

0.645

0.663

91.5

na

64.4

66.4

64.1

74.5

85.2

49.9

54.0

63.4

65.5

59.2

42.9

65.8

34.7

50.8

48.8

37.4

50.2

81.9

43.2

na

69.1

70.4

46.8

84.5

64.5

are shown on

154.0

na

225.0

134.0

152.0

169.0

170.0

149.0

152.0

153.0

226.0

123.0

188.0

157.0

135.0

185.0

182.0

127.0

191.0

161.0

123.0

na

169.0

197.0

119.0

155.0

192.0

f i gure

0.421

na

0.000

0.788

0.397

0.209

0.093

0.491

0.483

0.281

0.140

0.417

0.443

0.150

0.531

0.296

0.140

0.651

0.396

0.099

0.458

na

0.140

0.099

0.628

0.130

0.000

2.

17.60

na

25.60

14.10

16.60

18.10

19.40

11.20

14.30

15.50

18.90

10.70

12.00

17.90

9.09

14.70

19.60

8.62

12.00

18.00

9.84

na

17.80

20.70

9.44

17.40

21.10

17.20

na

11.50

11.30

12.00

13.60

15.50

8.57

9.79

12.20

11.20

10.80

7.68

11.60

6.37

8.63

8.79

6.52

8.74

14.90

8.18

na

12.50

12.20

8.39

15.10

11.70

100.0

na

0.0

100.0

100.0

100.0

0.0

106.0

100.0

143.0

140.0

105.0

100.0

100.0

118.0

110.0

100.0

150.0

100.0

100.0

117.0

na

120.0

100.0

130.0

100.0

100.0

0.834

na

0.975

0.864

0.883

0.762

0.798

0.803

0.977

0.902

1.280

0.776

1.160

0.764

0.761

1.180

0.800

0.909

1.130

0.954

0.837

na

0.907

0.958

0.953

1.050

1.070

Gannett Peak till deposits, 0.1-0.35 ka

1.810 37.7 0.75 7.24 4.68 589.0 508.0 19.00

na na na na na na na na

1.200 26.5 0.48 6.08 2.77 410.0 619.0 27.80

Audubon rock-glacier deposits, 0.95-2.4 ka

1.190 26.5 0.56 7.86 3.39 433.0 478.0 14.60

1.250 27.9 0.55 9.86 3.31 418.0 484.0 17.80

1.430 31.8 0.56 10.70 3.53 475.0 470.0 19.60

1.660 36.3 0.58 11.20 3.50 339.0 505.0 21.50

Triple Lakes rock-glacier deposit, 3-5.2 ka

0.918 21.5 0.47 5.70 2.91 352.0 494.0 11.10

1.100 24.4 0.59 6.54 3.65 387.0 481.0 13.90

1.320 29.6 0.00 6.54 4.20 411.0 491.0 16.20

1.030 31.8 0.55 6.25 3.29 475.0 519.0 18.60

Satanta Peak till deposits, inner moraine, 10-12 ka

1.170 25.2 0.56 6.41 3.53 499.0 486.0 11.20

0.866 17.4 0.48 5.10 3.01 410.0 464.0 9.80

1.290 27.8 0.57 5.59 3.48 538.0 471.0 19.10

0.723 16.3 0.00 4.21 2.29 295.0 439.0 8.87

0.892 23.0 0.00 4.98 3.50 458.0 454.0 13.20

0.916 20.6 0.00 5.39 2.84 374.0 473.0 19.80

Satanta Peak till deposits, outer moraine, 10-12 ka

0.796 15.6 0.43 4.27 2.72 342.0 471.0 8.63

1.020 21.3 0.59 5.03 3.59 517.0 499.0 10.30

1.650 37.4 0.84 6.55 4.65 613.0 512.0 19.00

0.887 19.5 0.43 4.22 2.76 334.0 425.0 9.79

na na na na na na na na

1.300 31.2 0.61 5.26 3.85 490.0 499.0 16.70

1.250 32.2 0.55 5.10 3.63 412.0 581.0 22.10

0.918 21.2 0.50 5.14 3.18 424.0 474.0 8.55

1.480 36.2 0.85 6.71 4.72 576.0 494.0 15.40

1.380 32.3 0.66 4.87 4.31 452.0 546.0 22.30

150.0

na

154.0

96.0

111.0

116.0

138.0

75.6

94.1

107.0

154.0

97.6

85.7

136.0

60.8

105.0

104.0

55.7

80.9

127.0

66.4

na

119.0

136.0

59.8

124.0

138.0

3.54

na

4.85

4.80

5.60

4.95

4.48

4.17

5.00

4.53

5.28

3.51

7.00

5.40

3.76

4.96

5.12

4.65

6.20

4.40

3.92

na

4.14

4.17

4.46

4.05

4.25

10.10

na

6.64

7.29

6.83

8.09

8.69

5.35

6.56

7.50

6.05

6.75

5.23

7.22

4.32

5.10

5.48

4.86

5.91

9.27

5.31

na

7.91

7.71

5.48

9.28

7.60

2.200

na

1.680

1.610

1.640

1.840

2.010

1.160

1.380

1.580

1.400

1.440

1.110

1.570

0.935

1.130

1.340

1.040

1.300

1.920

1.110

na

1.550

1.550

1.160

1.710

1.510
GPO 785-048/77402