Physical, Soil, and Paleomagnetic 

Stratigraphy of the Upper Cenozoic 

Sediments in Fisher Valley, 

Southeastern Utah 

U.S. GEOLOGICAL SURVEY BULLETIN 1686 

Prepared in cooperation with the U.S. Department of Energy 

FRONTISPIECE. Oblique aerial view of Fisher Valley, Utah. View is northwest, down the course of Onion Creek. The floor of Fisher 

Valley is in the foreground, perched above the erosional amphitheater eroded by the headwaters of Onion Creek into the upper Cenozoic 

basin-fil l deposits. The light-colored rocks in the middle distance are the cap rock of the Onion Creek salt diapir; to the right are Fisher 

Towers-Permian and Triassic rocks that form the northeast flank of the Fisher Valley anticline. The Colorado River flows southwest (to 

the left) at the base of the prominent cliffs in the distance. The Salt Valley anticline and Arches National Park are barely visible in the 

far distance (left). 

Physical, Soil, and Paleomagnetic 

Stratigraphy of the Upper Cenozoic 

Sediments in .Fisher Valley, 

Southeastern Utah 

By STEVEN M. COLMAN, ANNE F. CHOQUETTE, and 

FRED F. HAWKINS 

Prepared in cooperation with the U.S. Department of Energy 

The sediments and soils in Fisher Valley provide a record of geomorphic 

changes, deposition, and deformation associated with movement of the 

Onion Creek salt diapir. 

U.S. GEOLOGICAL SURVEY BULLETIN 1686 
DEPARTMENT OF THE INTERIOR 

DONALD PAUL HODEL, Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1988 

For sale by the 

Books and Open-File Reports Section 

U.S. Geological Survey 

Federal Center, Box 25425 

Denver, CO 80225 

Any use of trade names is for descriptive purposes only and does not imply 

endorsement by the U.S. Geological Survey. 

Library of Congress Cataloging-in-Publication Data 

Colman, Steven M. 

Physical, soil, and paleomagnetic stratigraphy of the Upper Cenozoic sediments 

in Fisher Valley, southeastern Utah. 

(U.S. Geological Survey bulletin; 1686) 

"Prepared in cooperation with the U.S. Department of Energy." 

Bibliography: p. 

Supt. of Docs. no.: I 19.3:1686 

1. Geology, Stratigraphic-Cenozoic. 2. Soils-Utah-Fisher Valley. 

3. Paleomagnetism-Utah-Fisher Valley. 4. Geology-Utah-Fisher Valley. 

4. Geology-Utah-Fisher Valley. I. Choquette, Anne F. 
CONTENTS 

Abstract 1 

Introduction 1 

Importance of the upper Cenozoic sediments in Fisher Valley 1 

Previous work 2 

Purpose 3 

Acknowledgments 3 

Geologic setting 3 

Physical stratigraphy 3 

Pliocene(?) gravel 4 

Basin-fill deposits 4 

Holocene deposits 6 

Soil stratigraphy 6 

Introduction 6 

Data and methods 8 

Rates of soil formation and ages 9 

Secondary calcium carbonate 9 

Secondary clay 11 

Summary 11 

Paleomagnetic stratigraphy 13 

Introduction 13 

Sampling 13 

Paleomagnetic remanence 13 

Remanence measurement 13 

Polarity classification scheme 14 

Stepwise demagnetization 14 

Petrography 16 

Interpretation of remanence 17 

Magnetostratigraphy 18 

Discussion 19 

Summary 20 

Late Cenozoic depositional history of the Fisher Valley area 21 

References cited 22 

Appendix: Descriptions and laboratory data, Fisher Valley soils, tables 4-6 25 

FIGURES 

1. Location map of the Fisher Valley area, Utah 2 

2. Photograph of basin-fill deposits exposed in the erosional amphitheater at the 

head of Onion Creek 4 

3. Geologic map and cross sections of the headwaters of Onion Creek, Fisher Valley, 

Utah 5 

4. Photograph showing Lava Creek (LC) and Bishop (B) ashes 5 

5. Photograph showing deformed Pliocene(?) gravels (Tg) 5 

6. Stratigraphic sections of the basin-fill deposits 7 

7. Photograph showing buried soils intercalated with basin-fill deposits in landslide scarp 8 

8. Diagram showing grain size and calcium carbonate data for soil I 9 

9. Diagram showing composite paleomagnetic stratigraphy in the basin-fill 

deposits 12 

10. Equal-area projection showing polarity classes of single-component paleomagnetic samples 14 

Contents V 
FIGURES 

11. Equal-area projections of magnetic remanence in samples showing normal (N), 

reversed (R), and indeterminate (I) polarities 15 

12. Projections of magnetic remanence from a sample containing multiple-polarity 

components 16 

13. Equal-area projection of magnetic remanence in reversed samples at natural 

remanent magnetism and during stepwise demagnetization 16 

14. Graphs showing magnetic intensity changes in five cores subjected to stepwise 

thermal demagnetization 18 

15. Graphs showing A, grain-size distribution of paleomagnetic samples related to 

B, interpreted polarity and C, intensity of natural remanant magnetism 19 

TABLES 

1. Ages of soils estimated from secondary calcium carbonate and clay contents 10 

2. Variation in magnetic intensity related to polarity of the Fisher Valley 

sediments 17 

3. Inclination of remanence related to polarity 17 

4. Soil descriptions and laboratory data, Fisher Valley soils 26 

5. Secondary carbonate in Fisher Valley soils 29 

6. Secondary clay in Fisher Valley soils 32 

VI Contents 
Physical, Soil, and Paleomagnetic Stratigraphy 

of the Upper Cenozoic Sediments in 

Fisher Valley, Southeastern Utah 

By Steven M. Colman, Anne F. Choquette, and Fred F. Hawkins 

Abstract 

The upper Cenozoic deposits in the Fisher Valley area, 

Utah, a thick sequence (> 145 m) of basin-fill sediments, contrast markedly with the thin, discontinuous deposits of this age 

that characterize the erosional terrain of the Paradox basin and 

the Colorado Plateau province. The sediments in Fisher Valley 

are second-cycle red beds derived from late Paleozoic and 

Mesozoic sedimentary bedrock. They are composed of interbedded fluvial and eolian sand, with minor fluvial gravel, 

which thins and grades into primarily alluvial-fan gravel towards 

the margins of the depositional basin. The sediments can be 

divided into depositional subunits that vary in thickness and 

distinctness and that define crude cycles related to diapiric 

deformation and climatic change. Each cycle begins with fluvial 

sands and gravels, grades upward into massive eolian sand, 

and ends with a period of landscape stability and soil formation. The sediments contain the Lava Creek ash (0.61 m.y.) and 

the Bishop ash (0.73 m.y.), which form important stratigraphic 

markers. 

The pre-Holocene buried soils interbedded with the Fisher 

Valley sediments provide important age information for the section. Most of the soils are polygenetic and are better developed 

than Holocene soils in the area. Assuming that secondary clay 

and carbonate in these soils are derived primarily from airborne 

sources and from the original contents of these materials in the 

sediments, and assuming that long-term rates of addition of 

these constituents have been constant, it is possible to estimate 

the age of each soil in the section. Long-term rates of accumulation of secondary carbonate and clay are calibrated by the total 

amount of these constituents above the stratigraphic markers 

provided by the Lava Creek and Bishop ashes and the BrunhesMatuyama paleomagnetic boundary. Ages estimated for the 

soils by these methods are generally consistent with other independent age estimates. Accordingly, the uppermost buried 

soil, which marks the end of deposition of the basin-fill 

sediments, began to form about 0.25 m.y. ago. This soil is overlain by Holocene eolian sand in which a very weak soil has 

developed. 

Paleomagnetic analyses of the Fisher Valley sediments 

proved that interpretable polarity results could be obtained from 

these relatively coarse-grained, second-cycle red beds. The 

magnetic stratigraphy suggests that the basin fill was deposited 

during the time of the Brunhes, Matuyama, and Gauss 

Chronozones and, therefore, began to accumulate more than 

2.5 m.y. ago. The sediments appear to contain a detrital remanent magnetization (DRM), carried mostly by specular hematite. 

The Matuyama reversed unit contains several intervals of normal polarity, which may correspond to normal events; 

however, the lack of detailed independent age control and 

evidence of post-depositional remagnetization in the reversed 

unit prevents positive identification of such polarity events. 

The upper Cenozoic sediments in Fisher Valley have been 

extremely useful in deciphering the history of the Onion Creek 

diapir, whose upward movement impeded the flow of Fisher 

Creek, caused deposition and progressive deformation of the 

sediments in Fisher Valley, and finally diverted Fisher Creek 

away from the Colorado River into the Dolores River. The Fisher 

Valley sediments preserve the pattern and timing of this diapiric 

movement and provide a unique, detailed record of the history 

of one of the Paradox basin salt structures. 

INTRODUCTION 

Importance of the Upper Cenozoic Sediments in 

Fisher Valley 

The upper Cenozoic sediments in Fisher Valley, 

southeastern Utah, constitute the best record of late 

Cenozoic conditions in the Paradox basin and perhaps 

in the entire Colorado Plateau province. Most of the 

Paradox basin and the Colorado Plateau province are 

characterized by erosional terrain and bare bedrock surfaces. Pliocene and Quaternary deposits in this area are 

highly local, thin, and discontinuous (Biggar and others, 

1981). In contrast, Fisher Valley contains a sequence of 

Pliocene and Pleistocene deposits more than 145m thick; 

these sediments record much of the late Cenozoic history 

of the area. 

In addition to recording general late Cenozoic 

environments, the deposits in Fisher Valley have been 

gently, but complexly ·deformed by movement of the 

Onion Creek salt diapir (Colman, 1983). The young 

history of salt movement in the salt anticlines of the 

Introduction 
"" '\ 

\ 

10 KILOMETERS 

5 MILES 

\ 

-M-r"7'"rrr--

" " SINBAD '.._ 

VALLEY 

EXPIANA TION 

Upper unit} Sediments of Fisher Valley 

Lower unit 

Intrusive igneous rocks of the La Sal 

Mountains D Mesozoic and Paleozoic bedrock 

I I II I I II I I 

Caprock of the Paradox Member of 

the Hermosa Formation 

Selected bedrock scarps 

--- Axial trace of the Sin bad- Fisher-CacheSalt Valley anticline 

Figure 1. Location map of the Fisher Valley area, Utah. From Colman (1983). 

Paradox basin is, in general, poorly known. The deposits 

in Fisher Valley are unique in that they allow detailed 

reconstruction of the late Cenozoic history of one of these 

salt bodies (Colman, 1983). 

2 Cenozoic Sediments, Fisher Valley, Utah 

Previous · Work 

The upper Cenozoic deposits in Fisher Valley have 

received relatively little study, despite widespread interest 
in the adjacent Onion Creek diapir. Dane (1935) described the Fisher Valley area in general terms in his 

reconnaissance work. Shoemaker (1954) mapped the 

detailed structures in the cap rock of the diapir and 

described deformation and unconformities in the adjacent upper Cenozoic deposits. Richmond (1962) described a section containing two volcanic ash beds in the 

Fisher Valley sediments. These two ash beds are now 

known to be the Lava Creek ash (0.61 m.y.) and the 

Bishop ash (0.73 m.y.) (Izett, 1981). Richmond also correlated some of the deposits in Fisher Valley with Quaternary deposits he mapped in and adjacent to the nearby 

La Sal Mountains. 

Purpose 

This report describes the detailed physical, soil, and 

paleomagnetic stratigraphy of the upper Cenozoic 

deposits in Fisher Valley. Together, these stratigraphic 

data form a time framework for reconstructing the late 

Cenozoic history of the Onion Creek salt diapir and for 

estimating environm(mtal conditions in the Fisher Valley 

area during this time. The depositional history of the 

Fisher Valley area is the primary focus of this paper. The 

history of the Onion Creek salt diapir has been inferred 

from the deformation of the Fisher Valley sediments 

(Colman, 1983) and will be only briefly discussed here. 

Acknowledgments 

This report results from a project partly funded by 

the Department of Energy to study the history of Fisher 

Valley and the Onion Creek salt diapir. We would like 

to especially thank R. L. Reynolds for support of the 

paleomagnetic work and D. Cheney who performed the 

laboratory soils analyses. We also appreciate the reviews, 

comments, and discussion we received from R. J. Hite, 

G. A. Izett, K. L. Pierce, M. N. Machette, R. L. 

Reynolds, J. G. Rosenbaum, and W. E. Scott. 

GEOLOGIC SETTING 

Fisher Valley is located in the Paradox basin region 

of southeast Utah. The Paradox basin is delineated by 

the extent of salt within the Paradox Member (Middle 

Pennsylvanian) of the Middle and Upper Pennsylvanian 

Hermosa Formation. Salt and gypsum of the Paradox 

Member form the cores of the northwest-trending anticlines of the region. Repeated solution and flowage of 

salt within the Paradox Member have characterized the 

development of these salt anticlines since Pennsylvanian 

time (Cater, 1970). 

The Fisher Valley salt anticline is part of a larger 

northwest-trending anticlinal structure that includes adjacent Cache and Sinbad Valleys (fig. 1) as well as Salt 

Valley to the northwest and Roc Creek Valley to the southeast. These valleys represent collapsed parts of structurally 

high sections along the crest of the anticline. The Onion 

Creek diapir, exposed in the collapsed crest of the Fisher 

Valley anticline, is essentially a cupola of salt emanating 

from the main diapiric core of the anticline. The cap rock 

of the diapir, along with a thick sequence of upper Cenozoic sediments, occupies the valley formed in the collapsed 

Fisher Valley anticline. The cap rock consists of the less 

soluble interbeds of the original evaporite sequence which, 

as a result of salt flowage and solution, are deformed into a chaotic jumble of gypsum, anhydrite, limestone, and 

shale. The sediments that are the subject of this report 

were deposited beginning in late Tertiary time, mostly in 

a basin east of the salt diapir. These basin-fill deposits 

consist of fluvial sand and gravel interbedded with lesser 

amounts of eolian silt and sand, all predominantly derived 

from Permian and Triassic formations that form the 

flanks of the Fisher Valley anticline. 

The basin-fill deposits are in contact with the cap 

rock of the Onion Creek diapir and are exposed in an 

erosional amphitheatre that Onion Creek has cut into the 

sedimentary basin adjacent to the diapir (fig. 2). The 

sedimentary basin roughly corresponds to the area of the 

erosional amphitheatre and part of the area overlain by 

the perched floor of Fisher Valley (fig. 3). The upper 

Cenozoic deposits are more than 145m thick and include 

the thickest Quaternary sequence in the Paradox basin 

and perhaps on the entire Colorado Plateau. 

PHYSICAL STRATIGRAPHY 

The upper Cenozoic deposits in Fisher Valley range 

from late Tertiary to Holocene in age (fig. 3). The basal 

unit is a Pliocene(?) or older gravel (unit Tg), which is 

complexly infolded into the cap rock of the Onion Creek 

diapir and is unconformably overlain by at least 145 m 

of Pliocene and Pleistocene basin fill. The basin-fill 

sediments (QTbl and Qbu) contain two volcanic ashes 

(fig. 4), at least nine buried soils, and along the basin 

margins at least four angular unconformities. The basinfill deposits are capped by 1-5m of Holocene eolian sand, 

which mantles the perched floor of Fisher Valley. A local 

unit of early Holocene alluvial sand (Qas of Colman and 

Hawkins, 1985), which apparently represents former 

valley-bottom deposits of Onion Creek, is inset into the 

basin-fill deposits near the eastern edge of the exposed 

diapir; it is about 30 m above the present channel of 

Onion Creek. Holocene alluvial deposits, 1-4 m thick, 

underlie channels and low terraces along Fisher and 

Onion Creeks. With the exception of the basal Pliocene(?) 

Physical Stratigraphy 3 
Figure 2. Basin-fill deposits exposed in the erosional amphitheater at the head of Onion Creek. Oblique aerial view looking 

southeast; cultivated area is the perched floor of Fisher Valley. Cap rock of the Onion Creek salt diapir is the light-colored area 

in the foreground. 

gravel, the deposits consist mostly of reddish-brown, very 

fine grained to coarse-grained sand and gravel derived 

from nearby red beds of the Permian Cutler and Triassic 

Moenkopi, Chinle, and Wingate Formations, which form 

the flanks of the Fisher Valley anticline. No macrofossils 

and only a few microfossils have been found in the Fisher 

Valley sediments, except in localized silt and sand of unit 

Qas. 

Pliocene(?) Gravel 

Pliocene(?) gravel (Tg), which underlies the basinfill deposits (fig. 5), occurs in an isolated exposure along 

Onion Creek near the southeastern edge of the cap rock 

(fig. 3). The unit is as much as 25 m thick and consists 

of a fine, clast-supported gravel in a matrix of fine to 

coarse sand with distinct planar to cross bedding. The 

clasts are composed predominantly of intrusive igneous 

rocks derived from the La Sal Mountains and Mesozoic 

sedimentary rocks; more than 75 percent of the deposit 

4 Cenozoic Sediments, Fisher Valley, Utah 

contains clasts of less than 10 em in diameter. Similar 

deposits in nearby Castle Valley and in the Geyser and 

Roc Creek drainages have been assigned a Pliocene age, 

although the units have not been radiometrically dated 

(Cater, 1970; Carter and Gualtieri, 1965; Hunt, 1956). 

Paleomagnetic data, discussed in the Paleomagnetic 

Stratigraphy section, suggest that these deposits are more 

than 2.5 m.y. old. 

Basin-fill Deposits 

The basin-fill sediments are subdivided into a lower 

unit (QTbl) and an upper unit (Qbu). Along the margins 

of the depositional basin, these units are separated by an 

angular unconformity located at the base of the Lava 

Creek ash; toward the center of the basin, the lower and 

upper units become concordant. On the basis of the 

amount of secondary calcium carbonate and clay in 

buried paleosols (Soil Stratigraphy section) and the magnetic stratigraphy (Paleomagnetic Stratigraphy section) 
Oe 

0 1000 METERS 

FEET 

A ~ 

5800 3000 FEET 

5600 

5400 

EXPLANATION 

Alluvium and low terrace deposits along Onion Creek (Holocene) 

Eolian sand on perched floor of Fisher Valley (Holocene) 

Basin-fill deposits, upper unit (Pleistocene) 

Basin- fill deposits, lower unit (Pleistocene and Pliocene) 

Pliocene (?) gravel containing igneous rocks from La Sal Mountains 

Mesozoic and Paleozoic bedrock 

Caprock of Middle Pennsylvanian Paradox Member of Hermosa 

Formation. The Paradox Member has repeatedly intruded the Onion 

Creek diapir, most recently in Quaternary time 

-------- Volcanic ash bed. LC , Lav~ Creek; B, Bishop 

___!1?_ Strike and dip of bedding. Bedding shown diagrammatically in sections 

by dashed lines 

B B' 

FEET 

A' 5600 

5400 

5200 

Figure 3. Geologic map and cross sections of the headwaters of Onion Creek, Fisher Valley, Utah. The nearby valley wall is 

projected into cross section A-A'. Circled letters represent the locations of sections shown in figure 6. From Colman (1983). 

of the sediments, basin-fill deposition began before 

2.5 m.y. ago and ended about 0.25 m.y. ago. The basinfill deposits as a whole can be divided into nine or ten 

subunits that are separated by buried soils. Within each 

subunit, the deposits tend to form a crude pattern, beginning with fining-upward fluvial sand and gravel, grading 

Figure 4. Lava Creek (LC) and Bishop (B) ashes. The ashes 

are interbedded with the upper and lower units of the basinfill deposits (Qbu and QTbl, respectively). Light band (S) above 

Lava Creek ash is soil I. View to the east. From Colman (1983). 

into and overlain by massive eolian sand, in which a 

paleosol has developed. The subunits vary greatly in 

thickness, tending to be thicker in the lower part of the 

section; the paleosols also vary greatly in degree of 

development. Together, the depositional pattern and the 

soils suggest crude cycles of alternating sedimentation and 

Figure 5. Deformed Pliocene(?) gravels (Tg). The gravels are 

folded into the cap rock of the Onion Creek diapir (Php) and 

are overlain by lower basin-fill deposits (QTbl). View to the 

north; trees are 2-3 m high. From Colman (1983). 

Physical Stratigraphy 5 
landscape stability. Such cycles could be related to either 

climatic changes or to deformation of the Onion Creek 

diapir. Because the depositional subunits are more 

numerous than the pulses of diapiric uplift inferred from 

the deformation of the deposits and from unconformities 

(Colman, 1983), climatic change is probably at least partly 

responsible for the sedimentation-stability cycles. 

The lower unit of the basin-fill deposits extends 

from the base of the Lava Creek ash to the Pliocene(?) 

gravel and is more than 100m thick. Toward the center 

of the basin, this unit consists of moderately to strongly 

indurated, fine to coarse, calcareous sand interbedded 

with gravel. It includes three or four buried soils, two 

of which (soils A and C, fig. 6) are well developed. Much 

of the unit contains local cut-and-fill structures and crossbedding; massive eolian sand composes the remainder. 

Toward the basin margins, the unit grades into predominantly matrix-supported gravel with minor lenses of 

medium to coarse sand; buried soils are not preserved 

near the basin margins. Minor angular unconformities 

occur in the unit near the edges of the basin. The Bishop 

ash occurs about 25 m below the top of a well-developed 

paleosol (soil C) that caps the unit (fig. 6). Buried soil 

A occurs about 40 m below the top of soil C and the base 

of the Lava Creek ash. Paleomagnetic data (Paleomagnetic Stratigraphy section) suggest that deposition of the 

lower unit began before 2.5 m.y. ago ; soil data (Soil 

Stratigraphy section) and the position of the Lava Creek 

and Bishop ashes indicate that it ended shortly after 

0.73 m.y. ago and well before 0.61 m.y. ago . 

The upper basin-fill unit is as much as 50 m thick 

and, toward the center of the basin, consists predominantly of massive to medium-bedded, calcareous, moderately indurated sand with cut-and-fill structures and 

minor lenses of fine to medium gravel. The Lava Creek 

ash locally occurs at the base of the unit and is as much 

as a meter thick. Where the Lava Creek ash is absent, 

the basal few meters of the unit tend to be thinly bedded 

to laminated and ash-rich. The unit contains at least six 

buried soils (soil D to soil I, fig. 6) and, near the basin 

margin, at least one angular unconformity-. Toward the 

edges of the basin, the unit thins and consists predominantly of moderately indurated, matrix-supported gravel 

with clasts as much as 1.5 m in diameter. A welldeveloped, buried calcic soil (soil I, fig . 6) caps the upper unit. Long-term rates of secondary carbonate accumulation (Soil Stratigraphy section) suggest that this 

soil began to form about 0.26 m.y. ago. In addition, 

uranium-trend analyses of the soil suggest an age of about 

0.21 m.y. for the upper (0-1 m) part of the parent 

material and 0.24 m.y. for the lower (1 - 3m) part (J. N. 

Rosholt, Jr., written commun., 1983). Therefore, the upper unit of basin fill, which extends from the Lava Creek 

ash to soil I, was deposited between about 0.61 and 

0.25 m.y. ago. 

6 Cenozoic Sediments, Fisher Valley, Utah 

Holocene Deposits 

A unit of unstratified, reddish-brown eolian sand 

and silt (Qe), 1-5 m thick, overlies soil I (fig. 6) and the 

upper unit of the basin-fill deposits. The eolian sand 

mantles the perched floor of Fisher Valley (fig. 3) and 

forms small dunes at the edge of the bluffs near the headwaters of Onion Creek. A very weak soil (soil J, fig. 6) 

has developed in the upper part of the eolian sand; the 

poor development of this soil and the preservation of 

dune morphology suggest a Holocene age for unit Qe. 

A localized unit of yellow to gray, nonindurated, 

calcareous silt and fine to coarse sand (Qas of Colman 

and Hawkins, 1985; area too small to be shown in fig. 

3) unconformably overlies the lower unit of basin fill near 

the eastern edge of the cap rock. The sediments are inset 

into the basin-fill deposits and are as much as 30m above 

the present channel of Onion Creek. They are as much 

as 10 m thick and contain laminated beds with layers of 

peaty material 1-2 em thick. A radiocarbon age of 

9330± 155 yr (DIC-2527) was obtained from peaty sand 

near the middle of the unit. These sediments also contain a fauna consisting of abundant ostracodes and terrestrial gastropods along with rare bivalves and aquatic 

gastropods. The faunal assemblage suggests that the 

sediments were deposited in a marshy environment whose 

water was derived from nearby, relatively fresh springs 

(R. M. Forester, written commun., 1983). Similar or 

slightly drier conditions now exist on the valley bottom 

in the erosional amphitheater at the headwaters of Onion 

Creek; unit Qas appears to represent material deposited 

on the former valley floor of Onion Creek, which was 

cut into the basin-fill sediments about 9,000-10,000 yr 

ago . 

Holocene alluvium, 1-4 m thick, underlies channels and low terraces along Fisher and Onion Creeks (unit 

Qa in fig. 3 and in Colman and Hawkins, 1985). The 

alluvium consists of nonindurated to slightly indurated, 

coarse calcareous sand and contains variable amounts of 

subangular to subrounded gravel. A very weak soil occurs in the upper part of the low terraces. Charcoal from 

these terraces yielded radiocarbon dates that are modern 

within analytical error (DIC-2525, 2536, 2537, 2538). 

SOIL STRATIGRAPHY 

Introduction 

Buried and surface soils are an important part of 

the stratigraphy of the upper Cenozoic deposits in the 

Fisher Valley area. These soils mark hiatuses in the 

deposition of the basin-fill sediments in Fisher Valley and 

reflect times of relative landscape stability in the area. 
0 

10 

© 

20 

30 

40 

(/) ? ® a: 

UJ 

fUJ 

~ 

~ 50 ~ 

:£ 

fa.. 

UJ 

0 

60 

QTbl QTbl 

70 

-:-:-:-:-:-:-:-:· Bl @ 

80 

- ---?----

90 

Tg 

100 

EXPLANATION 

Holocene ~ Qe Eolian sand 

Pleistocene Qbu } Basin-fiU 

QTbl depOSitS 

Tertiary Tg Pliocene (?) 

gravels 

LZZJ 

-

Volcanic ash beds: 

LC. Lava Creek; Bl. Bishop 

Soils 

---- ?- Correlations between sections, 

dashed and queried where uncertain 

~ Angular unconformity 

Figure 6. Stratigraphic sections of the basin-fill deposits. In the magnetic polarity column, solid is normal and open is reversed. Circled letters above columns are stratigraphic sections referred to in the text; 

locations are shown in figure 3. Sections are correlated by stratigraphic markers and by mapping of limited 

continuous exposures . 

Soil Stratigraphy 7 
In addition, the secondary clay and calcium carbonate 

contents of the soils are useful for estimating ages. As 

discussed in the section on physical stratigraphy, the soils 

mark the latter part of crude sedimentary cycles, in which 

deposition of fluvial sand and gravel is followed by 

deposition of massive eolian sand, in turn followed by 

soil formation. The buried soils are interspersed throughout the basinfill deposits; they are relatively rare in the 

lower part and become increasingly common in the upper part (figs. 6 and 7). The most strongly developed soil 

in the sequence occurs at the top of these deposits and 

marks the end of basin-fill deposition. 

Parent materials for the soils were derived from 

Paleozoic and Mesozoic red beds that surround the area. 

Most of the soils described here are developed in relatively 

fine grained, reddish-brown, calcareous eolian sand, 

which is locally interbedded with stratified fluvial sand 

and gravel derived from the same bedrock units. Near 

the edges of the late Cenozoic depositional basin, gravel 

becomes increasingly common, and many of the soils are 

eroded or truncated. In addition, multiple soils in the 

center of the basin merge into single soils because of 

nondeposition near the basin margins. 

Figure 7. Buried soils intercalated with basin-fill deposits in 

landslide scarp. Arrows indicate two prominent buried soils 

(soils I and C). Five less prominent buried soils occur between 

soils I and C, which are about 45 m apart vertically. 

8 Cenozoic Sediments, Fisher Valley, Utah 

Most of the buried soils in the section are more 

strongly developed than Holocene soils in the area. Under 

present conditions, B horizons are minimal, most soils 

are calcareous throughout, and degree of soil development is expressed primarily as calcareous C-horizon properties. In contrast, the buried soils in the basin-fill deposits 

in Fisher Valley have leached, relatively well developed 

B horizons and C horizons more strongly developed than 

those of Holocene soils. 

Many of the soils developed in the basin-fill 

sediments appear to be polygenetic, that is they formed 

under varying climatic conditions. The buried soils 

commonly show concentrations of secondary carbonate 

at more than one depth in the soil. The shallower zones 

are inferred to have been superimposed during more 

arid conditions on more deeply leached B horizons 

formed during relatively moist conditions. The most 

strongly developed soil (soil I), at the top of the basinfill deposits, most clearly shows polygenetic properties 

(fig. 8). 

The soils that will be discussed here are those 

developed in the upper (Qbu) and lower (QTbl) basinfill units of Colman and Hawkins (1985) and the soil in 

the overlying Holocene eolian sand. Soils in other surficial units in the Fisher Valley area are either eroded or 

are developed in deposits so young that soil development 

is minor. The climate of the Fisher Valley area is semiarid; 

climatic records for Gateway, Colo., and Moab, Utah 

(U.S. Dept. of Commerce, 1953; National Oceanic and 

Atmospheric Administration, 1981), suggest that for the 

Fisher Valley area, the mean annual temperature is about 

12 °C (range of monthly averages about -2 to 25 °C), and 

the mean annual precipitation is about 25 em (range of 

monthly averages about 1.3-3.0 em). 

Data and Methods 

Both field and laboratory data were collected for 

the soils developed in the basin-fill deposits in Fisher 

Valley (appendix, table 4). Field data consist of profile 

descriptions, including horizon identification, depth, 

Munsell color, texture, ped structure, and calcium carbonate morphology. Channel samples of each horizon 

were taken, and grain size, carbonate content, bulk density, and weight-loss-on-ignition were analyzed in the 

laboratory. Grain-size analyses were performed by sieve 

and pipette methods, carbonate content was determined 

by the Chittick gaseometric carbonate-dissolution technique (Dreimanis, 1962), and bulk density was measured 

by the water dispacement method on ovendried, paraffincoated ped samples (Chleborad and others, 1975). Soilhorizon nomenclature follows that of Birkeland (1984) 

and Guthrie and Witty (1982). 
HORIZON 

GRAIN SIZE. 

IN PERCENT 

CALCIUM CARBONATE, 

IN PERCENT 

0 10 20 

0 

Btb 

BKb1 

BtKb2 

BKb 

30 

L----, 

I 

I 

Lo 

I 

I 

40 0 10 20 30 40 

__________ j 

(./) 

a: 

w 

1-

w 

::2! 

~ 

KBb 

Kb1 

Kb2 

I 

I 

I 

I 

I 

I ::r:::· 

1- L ___ r __ _J l 

a.. 

w 

Ckb1 0 

2 

Ckb2 

Ckb3 

I 

!/Silt 

I 

I 

L----, 

I 

I 

'_j 

I 

I 

I 

I 

(Stage 

I r--J 

I 

I ___ j 

r----..1 

3 Ckb4 

I 

I 

I 

I 

II 

STAGE 

Ill IV 

Figure 8. Grain size and calcium carbonate data for soil I. Data from table 4, appendix. 

Rates of Soil Formation and Ages 

Soils in the Fisher Valley area provide stratigraphic 

and age information for the upper Cenozoic basin-fill 

deposits. In addition to the stratigraphic position of the 

soils, their degree of development and their rates of formation are of major concern. Recent studies of the degree 

of development and the rates of formation of arid-climate 

soils (Harden and others, 1985; Machette, 1985) show 

that progressive and systematic changes in soil development occur with time. Key soil properties that show these 

changes are the morphology and amounts of secondary 

calcium carbonate and clay. Quantitative measurements 

of these properties are especially useful in estimating soil 

ages and long-term accumulation rates. 

Secondary Calcium Carbonate 

Processes and rates of formation of calcic soils have 

been rather controversial. Calcic soils are characteristic 

of most of the arid and semi-arid regions of the western 

United States, but they have commonly been confused 

with other types of carbonate accumulation. However, 

recent work on calcic soils has resulted in better definitions of calcic soils, better descriptions of their morphology and other characteristics, and better understanding 

of the processes by which they form. (See Gile and others 

(1981) and Machette (1985) for summaries.) In addition, 

considerable data have been collected on the rates of formation of calcic soils and on variation in these rates with 

climate and carbonate source. 

Calcic soils are generally considered to form 

primarily by redistribution of (1) the original carbonate 

in soil parent materials and (2) secondary carbonate added 

to the soils from precipitation, either in the form of solid 

aerosols or as dissolved calcium carbonate (Gile and 

Grossman, 1979; Gile and others, 1981; Machette, 1985). 

Other sources of calcium, such as the weathering of 

calcium-rich rocks and precipitation from calcium-rich 

capillary fringe of shallow ground water, are thought to 

be negligible sources of Ca2+ (Machette, 1985). Parent 

materials of the soils in the Fisher Valley area are mostly 

quartz-rich sand derived from Paleozoic and Mesozoic 

red-bed sandstones; those parent materials contain significant amounts of primary CaC03 derived from the cement of the sandstone bedrock, but little or no other 

source of Ca2+. 

Because secondary carbonate accumulates in calcic 

soils in a systematic way with time (Gile and others, 1981; 

Machette, 1985), the amount of secondary carbonate in 

a soil can be used to estimate the duration of soil formation. Durations of soil formation, in turn, can be used 

to estimate ages of deposits in a stratigraphic section. We 

have used secondary carbonate to estimate the ages of 

the deposits in Fisher Valley, essentially following the 

Soil Stratigraphy 9 
methods of Machette (1978, 1985). These methods use 

long-term average rates of secondary carbonate accumulation to estimate durations of soil development. 

Total secondary carbonate in the soil (cS) 

(Machette, 1985) is defined as the sum of the secondary 

carbonate in each of the soil horizons (cs) where 

and C3 is the present weight percent carbonate, c1 is the 

original weight percent carbonate, P 3 is the present bulk 

density, P 1 is the original bulk density, and d is the 

horizon thickness. Original carbonate percentages and 

bulk densities were estimated from the lowermost, least 

altered C horizons of the soils (appendix, table 4) and 

from several samples of sediment that were not in soils. 

For gravelly parent materials, the calculations were made 

separately for the gravel (>2 mm) and for the sand and 

finer fractions (<2 mm), and total secondary carbonate 

values were corrected for the volume of the soil occupied 

by the gravel. All calculations of secondary carbonate for 

the soils in Fisher Valley are given in table 5 in the 

appendix. 

Ages for the vertical sequence of soils and sediments 

were estimated by methods analogous to those used by 

Machette (1978). Total secondary carbonate values (cS) 

were summed from all the soils above stratigraphic 

datums of known age. The Lava Creek ash (0.61 m.y.; 

Izett, 1981) and the Brunhes/Matuyama paleomagnetic 

boundary (0.73 m.y.; Mankinen and Dalrymple, 1979) 

were used as time datums. The total secondary carbonate 

above a time datum divided by the age of the datum gives 

an estimate of the long-term average rate of carbonate 

accumulation, and this rate is used to calculate the time 

required to accumulate the secondary carbonate in each 

soil (table 1). Results based on the two datums are nearly identical; the calculations using only one datum (the 

Brunhes/Matuyama boundary) are shown in table 1. 

This method of estimating ages from the secondary 

carbonate content of soils in a stratigraphic section requires several critical assumptions. First, the time represented by soil formation is assumed to be related to the 

time necessary for sediment deposition: either (1) soil formation takes up virtually all the time represented by the 

stratigraphic section, which is contradicted by the 

paleomagnetic results, or (2) the time required for soil 

formation is a constant proportion of the time represented 

by each sediment-soil unit. This assumption is convenient 

as a first approximation for fluvial and eolian sediments, 

but is difficult to evaluate except in terms of empirical 

results. 

The second major assumption is that the long-term 

rate of secondary carbonate accumulation is constant. 

Because of climatic controls on moisture and rates of 

aerosolic influx, short-term rates of carbonate accumulation clearly vary. The difference between carbonate accumulation rates for Holocene time compared to late 

Pleistocene time may be as much as a factor of two or 

more (Machette, 1985). However, because climate for 

about the last 1 m.y. has fluctuated around a nearly constant mean value with an overall periodicity of about 

100,000 yr (Hays and others, 1976), and because 

Holocene and late Pleistocene conditions represent 

climatic extremes, periods of more than about 50,000 yr 

may represent a nearly constant long-term average 

(Machette, 1985). 

Ages derived from long-term average rates of carbonate accumulation for the parent materials of soils in 

Table 1. Ages of soils estimated from secondary calcium carbonate and clay contents 

Soil Amount 

(g/cm2) 

Secondary carbonate 

Duration1 

(103 yr) 

Period 1 

(103 yr) 

Amount 

(g/cm2) 

Secondary clay 

Duration2 

(103 yr) 

Period2 

(1 03 yr) 

J 0.8 5 0-5 2.7 24 0-24 

I 39.8 257 5-262 35.9 318 24-342 

H 12.1 78 262-340 9.0 80 342-422 

G 8.1 52 340-392 3.3 29 422-451 

F 13.0 84 392-476 6.8 60 451-511 

E 13.2 85 476-561 14.4 127 511-638 

D 5.5 35 561-596 0.0 0 0 

------------------------------------------ Lava Creek ash, 610,000 yr ------------------------------------------

C 20.5 132 596-730 10.2 90 638-730 

------------------------------------ Brunhes/~atuyarna boundary, 730,000 yr ------------------------------------

B 9.4 61 730-791 6.6 58 730-788 

A 8.2 50 791-841 14.9 132 788-920 

1

Calculated from an average accumulation rate of 0.15 g/cm2/103 yr, derived from the cumulative amount of secondary carbonate (113 

g/cm2

) above the Brunhes/Matuyama boundary. 2

Calculated from an average accumulation rate of 0.11 g/cm2/103 yr, derived from the cumulative amount of secondary clay (81 g/cm2) 

above the Brunhes/Matuyama boundary. 

10 Cenozoic Sediments, Fisher Valley, Utah 
the Fisher Valley sediments (table 1) seem reasonable 

compared to what little is independently known about 

their ages. First, use of either the Lava Creek ash 

(0.61 m.y.) or the Brunhes/Matuyama paleomagnetic 

boundary (0.73 m.y.) as a time datum yields nearly identical long-term average rates of secondary carbonate accumulation, about 0.15 g/cm2 /103 yr. This rate 

compares favorably with the rate of 0.14 g/cm2/103 yr 

for the Beaver area in south-central Utah (Machette, 

1985), and with the maximum rate of 0.14-0.26 g/cm2/ 

103 yr for Spanish Valley (Harden and others, 1985), 

located about 27 km southwest of Fisher Valley. Second, 

carbonate accumulation rates for Fisher Valley suggest 

an age of about 260,000 yr for the parent material of soil 

I, the soil that caps the basin-fill deposits in Fisher Valley. 

This age compares favorably with ages of 210,000 and 

240,000 yr for the upper and lower parts, respectively, 

of the sediments in which soil I is formed (J. R. Rosholt, 

written commun., 1983), as determined by uranium-trend 

methods (Rosholt, 1985). 

Secondary Clay 

Clay content of soils, especially secondary clay, is 

a useful index of soil development. Total and secondary 

clay contents are commonly used as an indicator of age 

(Birkeland, 1984), but in few cases has clay content been 

quantitatively used to estimate numerical soil ages (Pierce, 

1979; Levine and Ciolkosz, 1983). In many respects, the 

accumulation of secondary clay is analogous to the accumulation of secondary carbonate and can be treated 

in a similar manner to estimate ages. However, the use 

of secondary clay to estimate soil ages involves several 

problems in addition to those encountered in using 

secondary carbonate for this purpose: (1) in many environments, weathering processes produce clay-size 

material in soils, in addition to that produced from other 

sources; (2) the original clay content of many parent 

materials is more variable and more stratified than is their 

carbonate content; and (3) B horizons are more prone 

to erosion than C horizons. 

Conditions in the Fisher Valley area are not conducive for clay formation by weathering. The climate is 

semiarid, and the parent materials contain high percentages of resistant quartz sand. Therefore, secondary clay 

derived from in-situ weathering is probably negligible. 

The primary sources of clay in the Fisher Valley soils are 

the original clay content of their parent materials and clay 

derived from aerosolic sources (dust and precipitation 

nucleii), the same sources that are dominant for secondary carbonate. Thus, secondary clay can be used in the 

same way that secondary carbonate was used to estimate 

ages, with additional uncertainty related to variable 

parent materials and erosion. 

Total secondary clay in a soil column (g/ cm2

) was 

calculated by methods similar to those used to calculate 

secondary carbonate (appendix, table 6). The calculations 

are somewhat simpler than those for carbonate, because 

the gravel fraction of the soils does not contain or contribute any secondary clay. Clay contents were corrected 

for the volume of the soil occupied by gravel. 

Ages for soil parent materials were calculated from 

secondary clay (table 1) by the same methods and with the 

same assumptions that were used for secondary carbonate. 

Long-term average rates of accumulation were calculated 

from the total amount of secondary clay above the time 

datum of the Brunhes/Matuyama boundary. The longterm rate was then used to calculate ages for the soils from 

the amount of secondary clay in each soil, assuming a 

constant proportion of time for sedimentation and a constant clay-accumulation rate. The arguments for the validity of these assumptions are the same as those presented 

for the age calculations made using secondary carbonate. 

The ages derived from secondary clay contents are 

consistently older, and probably less reasonable, than 

those derived from secondary carbonate contents. The 

age calculated for the parent material of soil J is 

24,000 yr, which is too old relative to geologic relations 

that suggest a Holocene age for the parent material. An 

age of 318,000 yr was calculated from secondary clay contents for soil I, which is considerably older than the 

uranium-trend ages (210,0QO and 240,000 yr) discussed 

in the Physical Stratigraphy section. Because the original 

clay contents of the soils are difficult to estimate due to 

variability and stratification in the parent material, the 

amount of secondary clay in soils I and J may have been 

overestimated. However, similar long-term average rates 

of secondary clay accumulation are derived whether the 

Lava Creek ash or the Brunhes/Matuyama boundary is 

used as a time datum, about 0.11 g/cm2/103 yr, which 

support the general validity of the method. 

Summary 

Secondary carbonate and clay contents provide a 

quantitative method of measuring soil development in the 

Fisher Valley sediments. These data in turn provide 

stratigraphic and time information for the sequence. For 

Fisher Valley, as for other semiarid and arid areas, the 

main sources of clay and carbonate in the soils seem to 

be aerosolic inputs and the original content of these 

materials in the sediments; contribution of carbonate and 

clay from weathering or other sources· appears to be 

negligible. Long-term rates of accumulation of both carbonate and clay appear to be nearly constant for intervals of 105 yr or more. 

The primary source of error in using carbonate- and 

clay-accumulation rates to calculate soil ages comes from 

Soil Stratigraphy 11 
POLARITY 

CHRONOZONE 

IJ) 

w 

:I: 

z 

:::> 

a: 

co 

0.73 m.y. 

<( 

~ 

<( 

>-

:::> 

1-

<( 

~ 

2.48 m .y. 

IJ) 

IJ) 

:::> 

<( 

(.!) 

SECTION A SECTION B 

n J J 

LAVA CREEK ASH 

•III ••III 

0~ 

(> ~ll 

~·(] llD 

DO 

<><> 

(] .. 

(] • 0 (](]~ 

~(]· (] . 

Olliii 

~~(] 

1:8:l ll0 

llllOD III• 

(](]~~® 

1J cg) (](] C8J ~ 

EXPLANATION 

0 Cube 

<> Cylinder 

0 Core 

• Normal 

1%1 Normal(?) 

0 Reversed 

1:8:1 Reversed (7) 

(] Indeterminate 

Unconformity 

IIIII Paleosol 

= Volcanic ash 

12 Cenozoic Sediments, Fisher Valley, Utah 

50 

SECTION C 

1 l 60 

70 

80 

IJ) 

a: 

w 

1-

w 

~ 

~ 

:i 

90 1-

a.. 

w 

0 

100 

110 

.1%1 

• •• 120 

1%1 • 

•• 

••• •• 130 
difficulties in estimating the original carbonate and clay 

contents of the parent materials; this problem seems more 

serious for clay than for carbonate. Rates of carbonate 

accumulation produce ages that seem more reasonable 

than those derived from rates of clay accumulation. The 

long-term rate of carbonate accumulation at Fisher Valley 

(about 0.15 g/cm2/103 yr) is similar to rates calculated 

for nearby areas and yields ages that are consistent with 

independent age control. 

PALEOMAGNETIC STRATIGRAPHY 

Introduction 

The basin-fill deposits in Fisher Valley contain few 

materials from which the age of the sediments can be 

estimated. The Lava Creek and Bishop ashes and several 

paleosols provide age control for the upper part of the 

stratigraphic section, but the lower part of the section, 

below the Bishop ash, contains very few datable 

materials. Consequently, paleomagnetic stratigraphy provided the primary information about the age of these 

sediments. 

Although coarse-grained, second-cycle red sediments, such as those in Fisher Valley, are generally 

thought to be poor recorders of paleomagnetic directions, 

preliminary samples and analyses indicated that the 

deposits contained a credible paleomagnetic record. 

Where stable sediments (paleosols and volcanic ash beds) 

occurred in the section, the observed paleomagnetic 

record was consistent with the polarities in the standard 

paleomagnetic time scale (Mankinen and Dalrymple, 

1979), and adjacent samples yielded reasonably consistent polarities. After further sampling throughout the part 

of the stratigraphic section below the Lava Creek ash 

(QTbl in fig. 6), we were able to define the paleomagnetic 

stratigraphy. Ages of the volcanic ash deposits and the 

buried soils in the upper part of these sediments in conjunction with the magnetic reversal stratigraphy in the 

section were thus used to investigate the timing of 

remanence acquisition and to correlate polarity zonation 

in the sediments with the standard magnetic-polarity time 

scale to determine the timing of deposition (Choquette 

and Colman, 1983). 

Sampling 

We collected oriented samples from three stratigraphic sections exposed in the headwaters of Onion 

Creek. The sampled sections, A, B, and C (fig. 3), are 

35, 15, and 65 m thick, respectively. A total of 168 

samples were collected at 1- to 2-m intervals from 70 

horizons in the sections (fig. 9). Two or more samples 

were collected from most of these horizons. 

Three techniques were used to obtain samples both 

from oriented hand specimens in the laboratory and from 

undisturbed exposures in the field. Most of the samples 

(146) were collected by carving cubes from planed surfaces in the sediments. The cubes were then placed in 

plastic sample boxes. Fourteen samples were obtained by 

pushing thin-walled plastic cylinders into the sediments. 

The cylinders and boxes were sealed with either plastic 

lacquer or acetate cement. Eight samples were drilled with 

a diamond core bit. The cubes, cylinders, and drill cores 

have volumes of 3.2, 6.5, and 10.9 em\ respectively. We 

used a Brunton compass to orient all samples in the field 

with an estimated accuracy of ±5°. 

Sampling was conducted in several phases. Initially, we collected a set of samples at widely spaced intervals to determine the stability of magnetic remanence 

upon demagnetization and the polarities of sediments in 

the composite section. Subsequent samples were collected 

at more closely spaced intervals to locate polarity boundaries and to substantiate polarities in previously sampled 

horizons. 

Paleomagnetic Remanence 

Remanence Measurement 

Remanent magnetization was measured in a digital 

spinner magnetometer with a sensitivity of about 5 X 1Q-4 

Aim (amperes/meter). Remanent directions for samples 

collected from tilted beds (maximum dip, 14 ')were corrected for bedding attitudes. 

The core samples were thermally demagnetized in 

steps of 100 ° to 200 °C at temperatures ranging from 100 

to 680°C. The samples from plastic cubes and cylinders 

were demagnetized in a three-axis tumbler at peak alter:. 

nating fields (AF) of 10, 20, 40, and 60 mT (milliteslas). 

Peak AF intermediate to or exceeding these levels were 

Figure 9 (facing page). Composite paleomagnetic stratigraphy in the basin-fill deposits. Sample polarities are shown to the right 

of the stratigraphic sections. Queried intervals in the Matuyama Polarity Chronozone denote subzones containing normal polarities. 

These subzones may correspond to normal polarity subchronozones and (or) post-depositional magnetic overprinting of the 

sediments. Polarity time scale from Mankinen and Dalrymple (1979). 

Paleomagnetic Stratigraphy 13 
applied to samples showing unstable directions or large 

intensity changes at low levels of demagnetization and 

to those failing to reach stable directions by 60 mT. 

Polarity Classification Scheme 

Each sample was assigned one of the following 

polarity classes: normal, normal(?), reversed, reversed(?), 

or indeterminate (N, N?, R, R?, I, respectively). Each 

of these classes is represented by a region of an equalarea projection (fig. 10). 

The limits for N and R polarity are based on estimated limits of secular variation and inclination error. 

Any direction within 30 °, the estimated limit of secular 

variation (Channel, 1982), of the normal (reversed) 

------

N 

s 

EXPLANATION 

Projection to lower hemisphere (positive inclination) 

Projection to upper hemisphere (negative inclination) 

Normal Polarity 

Reversed Polarity 

Q Normal (?) Polarity 

Reversed (?) Polarity 

Indeterminate Polarity 

Expected mean dipole directions 

Figure 10. Equal-area projection showing polarity classes of 

single-component paleomagnetic samples. Limits of N and R 

polarities (stippled) are based on estimated secular variation 

and inclination error. Limits of N(?) and R(?) polarities are 60 

angular degrees from the expected dipole field at the sampling locality. 

14 Cenozoic Sediments, Fisher Valley, Utah 

axial dipole field was assumed to be N (R). However, 

depositional remanent magnetism may be subject to a 

variety of errors including inclination error, currentrotation error, and bedding error (Verosub, 1977); and 

laboratory tests suggest that these errors can be significant (King, 1955; Griffiths and others, 1957; Rees, 1961). 

Although it is difficult to evaluate the actual influence 

of such errors in the Fisher Valley deposits, we decided 

to expand the limits of the N (R) region by applying an 

empirical function for inclination error to the boundary 

defined by secular variation. We used the empirical function developed by Griffiths and others (1960) and allowed 

for a maximum inclination error of 30°, which occurs 

for an ambient field inclination of 58 °. The resulting 

boundary is shown in figure 10. We arbitrarily set the 

limit of N? (R ?) polarities at 60 angular degrees from the 

normal (reversed) axial dipole direction. These polarity 

limits allow considerable variation in magnetic 

remanence, but they seem reasonable considering the 

directional scatter that can result from post-depositional 

compaction and mechanical forces accompanying deposition of coarse-grained sediments (Verosub, 1977). 

Samples that contained a single magnetic component (fig. 11A) were classed according to the regions 

shown in figure 10. Most of these samples showed consistent directions at demagnetization levels exceeding 

20 mT or 300°C. However, some samples yielded stable 

directions during low levels of demagnetization but 

showed large directional changes and fluctuating 

magnetic intensities after demagnetization at AF exceeding about 40 mT. This behavior was attributed to 

anhysteritic remanent magnetization (ARM) acquired 

during AF treatment, and the polarity of such samples 

was determined from directions measured at low AF 

treatment. 

Samples that contained multiple magnetic components were classified on the basis of orthogonal projections of remanent vectors (Zijderveld, 1967). Samples 

were classed N? or R? when the plots revealed N, N?, 

R, or R? components that remained stable for at least 

three consecutive levels of demagnetization (fig. 12). All 

other samples that showed either consistent I directions 

or unstable directions upon demagnetization were classed 

I (fig. 11B). 

Stepwise Demagnetization 

Magnetic intensity of the paleomagnetic samples 

ranged from 0.3 to 24.8 X 10-3 Aim. The geometric 

mean natural remanent magnetization (NRM) intensity 

of all samples was 2.2 X 10-3 Aim. Magnetic intensities 

differed considerably between normal- and reversedpolarity zones and between sample polarity classes (table 

2). Mean NRM intensity of reversed-polarity samples was 

consistently lower than that of normal-polarity samples. 
A 

w 

B 

w 

+ 

JO<\@ NR~ 

N 

60 NRM @ 

G)r~60® 

+ 

NRM 60 NRM~v l.,_NRM 

+ 8~ 

+ + 

+ 

NRM~@ 60 

NRM 60 

0 

s 

N 

s 

EXPLANATION 

• 

0 

Lower hemisphere projection 

Upper hemisphere projection 

+ 

+ 

e60 Level of stepwise demagnetization, in milliteslas 

G) Sample reference number 

E 

E 

Figure 11. Equal-area projections of magnetic remanence 

in samples showing normal (N), reversed (R), and indeterminate (I) polarities. A, samples yielding single component 

N polarity (1-4) and R polarity (5-8); 8, samples yielding I 

polarity. Sample remanence was measured prior to 

demagnetization (NRM) and at a minimum of four levels of 

AF demagnetization: 10, 20, 40, and 60 mT (milliteslas). 

In reversed samples, magnetic intensity commonly 

increased after each of the first few steps of AF or thermal demagnetization. Fifty-eight percent of the R samples 

showed an increase in magnetic intensity during 

demagnetization. Intensity peaks during demagnetization 

suggest that antiparallel magnetic vectors were removed 

at low levels of demagnetization. These intensity increases 

commonly coincided with a change from normal or intermediate vector directions to consistent reversed directions (fig. 13). In contrast, only 7 percent of theN samples 

showed post-NRM intensity peaks. Notably, these normal samples were located in the upper 5 m of the Gauss 

Polarity Chronozone and in a normal horizon in the 

Matuyama Polarity Chronozone, where the sediments 

were presumably most susceptible to magnetic overprinting. In summary, reversed magnetic components 

were generally not apparent in normal samples, whereas 

normal magnetic components were commonly removed 

during demagnetization of reversed samples. 

The decrease in magnetic intensity upon thermal 

demagnetization of the drill core samples provides some 

indication of the source of magnetic remanence in the 

basin-fill sediments. Thermal demagnetization to 200°C 

removed about 35-60 percent of the NRM in most of the 

samples (fig. 14), suggesting the presence of goethite (Neel 

temperature, 120°C). About 5-20 percent of the NRM 

was removed between 500 ° and 600 °C, suggesting some 

contribution from magnetite (Curie temperature, 580°C), 

although remnents of unaltered magnetite were sparse in 

polished sections of the sediments. After demagnetization to 600 OC, about 20-60 percent of the NRM remained 

in the samples, which suggests that hematite (Neel 

temperature, 680 °C) contributes to the magnetic 

remanence of the samples. Magnetic intensity changes 

resulting from thermal demagnetization of the eight core 

samples suggest that hematite, goethite, and perhaps 

magnetite contribute to the magnetic remanence in the 

basin-fill deposits. 

The mean inclination of sample remanence in N and 

R samples, based on measurements after demagnetization at 20 mT (or 200°C) and 60 mT (or 600°C), was 

about 17 ° shallower than the inclination of the axial 

dipole field (58~ at the sampling site. The range of differences between measured inclinations and the inclination predicted by the axial dipole model is similar in 

magnitude to an "inclination error," commonly 

associated with depositional remanent magnetization 

(DRM) in silts and sands (King, 1955; Griffiths and 

others, 1957; Rees, 1961). The differences in inclination 

between N and R samples (table 3) may in part reflect 

depositional effects, but they may also be related to 

normal-polarity overprints in the reversed samples. 

Paleomagnetic Stratigraphy 15 
w 

A 

~40 

L:l20 

N B 

w 

+ E 

UP 

s 

A 

Lower hemisphere projection 

Upper hemisphere projection 

demagnetization levels in milliteslas 

-4 

EXPLANATION 

B 

(") 

I 

0 

N 

2 

-2 

-4 

s 

1 o___ Magnetic declination 

20o-- ---o Magnetic inclination 

4 6 

MOMENT (1 o-3 A/m) 

demagnetization levels in milliteslas 

moments in 1 o-3 amperes/meter (A/m) 

8 

E 

10 

DOWN 

Figure 12. Projections of magnetic remanence from a sample containing multiple-polarity components. A, equal area projection; B, orthogonal projection. The projections indicate a reversed-polarity component (40 to 60 mT) in addition to a normalpolarity overprint (NRM to 30 mT) that was removed upon stepwise AF demagnetization. 

+ • + 

NRM 20mT or 200oC 

+ • • + 0 

• 0 + 

0 

+ + + + + i + + + 

• 0 0 

• Oo 0 

'b 0 0 0+ 'lt 0 

od-c:JJ 0 0 0 08 0 • 0 0 00 

0 0 

0 

cPo0 0 og o 

0 -+-go "~ o -jOOO 0 

0 0 0 0000 0 ~ 0 • • + 0 • .oo 

+ 

• 0 0 

0 0 0 

0 0 0 +00 0 0 0 

o cflo o 

0 00 0~ 0 

o o oo o fbo 0 0 0 

EXPLANATION 

0 Negative inclination (upper hemisphere projection) 

• Positive inclination (lower hemisphere projection) 

Figure 13. Equal-area projection of magnetic remanence in 

reversed samples at natural remanent magnetism and during 

stepwise demagnetization. 

16 Cenozoic Sediments, Fisher Valley, Utah 

Petrography 

Polished thin sections from indurated hand 

specimens were examined under reflected light to identify magnetic minerals in the basin-fill sediments. Detrital 

grains of specular hematite are abundant in the polished 

sections. The detrital hematite, about 3-100 ~tm in 

diameter, consists predominantly of martite (pseudomorphic hematite after magnetite) with little or no relict 

magnetite. Most of the detrital hematite grains are much 

smaller than the adjacent silicate grains. Hematite also 

occurs as thin coatings on specular hematite, biotite, and 

other iron-bearing minerals. 

Dominant grain size was determined for 103 (61 

percent) of the paleomagnetic samples, including at least 

one sample from each of the horizons shown in figure 

9. The dominant grain size in the samples ranges from 

very fine to medium sand (fig. 15A). Both the reliability 

of polarity interpretations and the geometric mean NRM 

intensities of samples in the grain-size classes decrease 

with increasing grain size (figs. 15B and C). Differences 

between the mean NRM intensities of samples in the 

grain-size classes were evaluated using analysis of variance 

(ANOVA) and the Student-Newman-Keuls multiple 
Table 2. Variation in magnetic intensity related to polarity of the Fisher Valley sediments 

[NRM intensity was measured prior to demagnetization and the maximum intensity was the maximum 

observed during stepwise demagnetization. NRM, natural remanent magnetization; A/m, amperes/meter] 

Geometric 

mean of 

Polarity NRM 

classification intensities 

(10-3 A/m) 

By Polarity Chronozone: 

Brunhes 3.0 

Matuyama 1.8 

Gauss 4.5 

By sample: 

Normal 3.7 

Normal(?) 2.1 

Reversed 1.9 

Reversed{?) 1.6 

Indeterminate 1.7 

Geometric 

mean of 

maximum 

intensities 

(lo-3 A/m) 

3.0 

2.0 

4.7 

3.7 

2.2 

2.2 

1.9 

1.9 

Number 

of 

samples 

23 

125 

20 

168 

44 

14 

44 

21 

45 

168 

Table 3. Inclination of remanence related to polarity 

[Comparison was restricted to samples showing only one polarity component during stepwise demagnetization. mT, milliteslas; X:, mean; s, standard deviation; n, number of samples] 

Measured inclinations minus axial 

dipole inclination (58°) in degrees 

Sample 

polarity 

20 mT or 200 °C 60 mT or 600 oc 

Normal (N) 1 

Reversed (R) 

8.5 

23.0 

14.3 

21.4 

n 

35 

44 

13.3 

21.7 

18.7 

19.1 

n 

32 

43 

1

Normal samples in Matuyama Polarity Chronozone were omitted due to possible overprints. 

comparison of sample means (Zarr, 1974). Assuming the 

grain-size samples are random, the mean NRM intensity 

of the very fine grained samples is significantly higher 

(a =0.001) than that of the fine- and the medium-grained 

samples. The mean NRM intensities of fine- and mediumgrained samples were not significantly different 

{a=0.05). 

Interpretation of Remanence 

The magnetic mineralogy and magnetic characteristics of the paleomagnetic samples strongly suggest that 

the primary magnetization in the basin-fill sediments is 

a DRM carried by detrital specular hematite. The basis 

for this interpretation is as follows. Highly altered detrital 

specular hematite is abundant in polished sections of the 

sediments. The magnetic minerals in the deposits are 

similar to those described for the source rocks which indicates that these minerals have not undergone significant post-depositional alteration. The detrital hematite 

grains are of a size range that could have become oriented 

within the interstices of the larger sand-sized particles at 

the time of deposition. Intensity changes upon demagnetization also indicate that part of the remanence is carried 

by hematite. Most of the reversed and normal polarities 

in the deposits remained stable throughout demagnetization and subsequently defined distinct polarity zones in 

the stratigraphic seCtion. Furthermore, the magnetic inclination in samples containing single-polarity components (N and R samples) is shallower than the 

inclination of the axial dipole field. The shallow inclinations are suggestive of inclination error that often results 

from DRM. Lastly, the Brunhes-Matuyama polarity 

boundary (0.73 m.y.) in the sediments is located near the 

0.73 m.y.-old Bishop ash, which indicates that the 

sediments were magnetized near the time of deposition. 

Paleomagnetic Stratigraphy 17 
100~-----------,------------~------------~------------~------------~------------.-~ 

80 

60 ---------------·-- a: 

~ -- z 

u. 

0 

---- + _____ ..... _---~· -+:-----------· 

1-

z 

w 

u 

a: 

w 

a.. 

40 

20 

0~----------~~----------~------------~------------~------------~------------~~ 

0 100 200 300 400 500 600 

MAXIMUM TEMPERATURE (CO) 

Figure 14. Magnetic intensity changes in five cores from unit QTbl subjected to stepwise thermal demagnetization. 

However, magnetic overprints in some of the 

paleomagnetic samples suggest that a secondary chemical 

remanent magnetization (CRM) and (or) viscous remanent magnetization (VRM) has altered the primary 

depositional remanence. Multiple-polarity components in 

sediments in the reversed-polarity zone indicate a postdepositional secondary magnetization. These samples 

showed directional changes, from normal to reversed, 

coincident with an increase in magnetic intensity upon 

demagnetization. Several sampled horizons in the 

reversed-polarity chronozone contain both normal and 

reversed polarities, suggesting normal-polarity remagnetization. The anomalously shallow inclination of R samples 

compared to that of N samples (table 3) is consistent with 

models of chemical overprinting (Patterson, 1981; Larson and Walker, 1982), in which dominantly reversed 

directions are effectively "pulled" towards shallower 

directions by normal polarity components. 

18 Cenozoic Sediments, Fisher Valley, Utah 

Hematite replacements of biotite or remanents of 

magnetite in detrital hematite and hematite films around 

grains of specular hematite or biotite could carry a postdepositional CRM if this hematite formed after deposition. It is difficult to determine which iron-oxide minerals 

formed in situ because similar hematite minerals occur 

in the source rocks. However, on the basis of the high 

degree of weathering of magnetic minerals in the source 

beds and the abundance of detrital hematite grains in the 

Fisher Valley sediments, the primary remanence appears 

to be related to the detrital hematite. 

Magnetostratigraphy 

Sample polarities and the interpreted magnetic 

stratigraphy of the composite stratigraphic section are 

shown in figure 9. Seventy-three percent of the samples 
A 

(/) 60 LlJ 

_J 

a.. 

~ 40 (/) 

u.. 

0 

a: 

w 

co 

~ 

::J 

z 

20 

0 

B 

(/) 100 w 

_J 

a.. 

~ 

<! 

(/) 

0 50 

fz 

w 

u 

a: 

w 

a.. 0 

c 

Very fine 

sand Fine sand Medium J 

sand 

GRAIN SIZE 

DISTRIBUTION 

POLARITY 

INTERPRETATION 

D Indeterminate 

~ N(?), R(?) 

fiii!N,R 

~E a:::::r 

ZM 

uO 

a:=-

ti:= 

~u; 

oz 

ww 

(.9fl 1 GEOMETRIC MEAN I L----~1 NRM INTENSITY 

z 0 .0625 0.125 0 .25 0.5 

DOMINANT GRAIN SIZE, IN MM 

Figure 15. A, grain-size distribution of paleomagnetic 

samples related to 8, interpreted polarity and C, intensity of 

natural remanent magnetism. 

yielded interpretable (N, N?, R, R?) polarities. The composite section contains three major polarity zones forming a normal-reversed-normal sequence. These appear 

to represent the Brunhes (normal), Matuyama (reversed), and Gauss (normal) Polarity Chronozones based 

on the magnetic stratigraphy and other evidence 

presented in the following discussion. The BrunhesMatuyama boundary occurs in section A about 27 m 

below the Lava Creek ash and in section B about 5 m 

below the Bishop ash and 30 m below the Lava Creek 

ash. Minimum thicknesses of the Brunhes, Matuyama, 

and Gauss Polarity Chronozones are 76, 45, and 20m, 

respectively. The actual thicknesses of the Matuyama 

and Gauss units are difficult to estimate because (1) the 

exact correlation between sections A and B, which contain the top of the Matuyama, and section C, which contains the base of the Matuyama, is uncertain; and (2) 

the base of the sediments deposited during the Gauss 

Polarity Chronozone is not expos~d. 

The age of the Brunhes-Matuyama boundary has 

been estimated to be 0.73 m.y. (Mankinen and Dalrymple, 1979). Our interpretation of the BrunhesMatuyama polarity boundary in the Fisher Valley sediments is based largely on the proximity of the polarity 

change to the radiometrically dated Lava Creek and 

Bishop ashes (0.61 and 0. 73 m.y., respectively; Izett, 

1981). Although the Bishop ash was not found in section A, the distances between the N/R polarity boundary 

and the Lava Creek ash are similar in sections A and B 

(fig. 9). 

Geologic mapping (Colman and Hawkins, 1985) indicates that most of section C underlies sections A and 

B. The older age for section C, the relative thicknesses 

of the reversed and lower normal polarity units, and the 

uniform polarities within the lower normal polarity unit 

suggest that the lowermost sediments in section C were 

deposited during the Gauss Polarity Chronozone. This interpretation also allows for the possibility that one or more 

of the normal horizons within the Matuyama Polarity 

Chronozone represent normal-polarity subchronozones. 

Normal polarities were generally well resolved and 

consistent throughout the Brunhes and Gauss polarity 

units. The resolution of polarities was less consistent in 

the Matuyama Polarity Chronozone. Reliable polarities 

(N, R) represent more than 70 percent of the samples in 

the normal (Brunhes and Gauss) polarity zones compared 

to 40 percent in the reversed (Matuyama) polarity zone, 

and the reversed-polarity zone contains a higher proportion of samples showing indeterminate polarities. Seven 

subzones within the reversed-polarity zone contain normally magnetized samples, and several horizons contain 

both normal and reversed samples (fig. 9). The normal 

polarities and the polarity conflicts might be the result 

of younger normal remagnetization of portions of these 

subzones. Evidence that suggests partial remagnetization 

of reversed samples is presented in the Discussion section. Some of the normal polarities in the Matuyama 

Polarity Chronozone may reflect deposition during 

normal-polarity subchronozones; however, this conclusion is tenuous because of the lack of detailed independent age control and because of the possibility of younger 

normal remagnetization. 

Discussion 

The timing and processes by which red sediments 

acquire remanent magnetization are subjects of considerable debate (Collinson, 1965; Turner, 1979; Van 

Houten, 1968; and others). Several studies addressing this 

problem have been conducted on one of the source rocks 

for the Fisher Valley sediments, the Triassic Moenkopi 

Formation, in which the magnetization has been attributed to both DRM (Elston and Purucker, 1979) and 

CRM (Larson and others, 1982). Studies of first-cycle red 

beds of late Cenozoic age indicate that chemical 

remagnetization can occur as much as 20 m.y. after 

deposition (Boblitt and others, 1974), can take place at 

a nonuniform rate, and can effectively obscure primary 

depositional remanence (Larson and Walker, 1975). The 

magnetic stratigraphy in the Fisher Valley sediments 

Paleomagnetic Stratigraphy 19 
offers some insight into the acquisition and long-term 

stability of magnetic remanence in second-generation redbed deposits. 

The coarse-grained, fluvial sediments in Fisher 

Valley apparently became magnetized near the time of 

deposition and, if our interpretation of the magnetic 

stratigraphy is correct, have carried a stable remanence 

for more than 2.5 m.y. The DRM in such sediments can 

result from the alignment of fine-grained magnetic particles within the interstices of the sand-sized particles, during or soon after deposition. In contrast to first-cycle red 

sediments, the preservation of primary remanence in these 

second-cycle red beds appears to be due partly to the 

highly oxidized state of magnetic minerals prior to deposition and partly to the pervasive calcium carbonate cement 

in the deposits. Rates of authigenesis and chemical 

remanence acquisition should decrease with decreasing 

amounts of unaltered iron-bearing minerals. In addition, 

calcium carbonate cement can protect partially altered 

minerals from further alteration by limiting ground-water 

infiltration (Walker and others, 1978). 

However, some of the sediments in the Matuyama 

polarity unit do show evidence of partial remagnetization. N and R samples in single sampled horizons from 

this zone suggest that the overprints can effectively cancel 

the primary detrital remanence. The overprints could 

result from either viscous or chemical remagnetization 

of the sediments. In the Fisher Valley sediments we 

cannot distinguish between VRM or CRM, and both 

may be present. Hematitic sediments can acquire a 

VRM (Dunlop and Sterling, 1977) but the process is 

not well understood. Chemical components may have 

resulted from in-situ alteration of incompletely oxidized 

detrital ferrous iron-bearing minerals or from interstitial 

ferric oxyhydroxide phases formed locally from 

redistributed iron (Larson and others, 1982; Walker and 

others, 1981). Unaltered magnetite within detrital grains 

of hematite (martite) and grains of biotite are two possible sources in the Fisher Valley sediments for remanence 

acquisition. Mineralogic sources of magnetic remanence 

in red sediments are difficult to identify positively 

(Walker and others, 1981; Collinson, 1983). It is especially difficult to recognize minerals carrying magnetic components in second-cycle red beds because the sediments 

are derived from deposits which contain authigenic iron 

oxides. 

Indeterminate sample polarities could also be 

caused by mechanical reorientation of magnetic particles 

during deposition or by the presence of highly magnetized sandstone clasts in the samples. Sandstone fragments, generally less than 3 mm in diameter, occur locally 

in the deposits. Although we avoided sampling material 

that contained large bedrock fragments, small strongly 

magnetized fragments could significantly affect sample 

remanence (Larson and others, 1982; Larson, 1981). 

20 Cenozoic Sediments, Fisher Valley, Utah 

Although some of the sediments in the Gauss 

Polarity Chronozone showed an increase in magnetic intensity upon demagnetization, none of the samples 

showed clear directional evidence of multiple polarity 

components. Probably all polarity zones have acquired 

a CRM and (or) a VRM, but only the Matuyama Polarity Chronozone contains clear evidence of multiple polarity components. The absence of reversed magnetic 

components in the older Gauss polarity unit may result 

from ( 1) the cancellation of reversed overprints by 

younger normal overprints acquired during the Brunhes 

Polarity Chronozone or (2) the change in hydrological 

conditions in the deposits that occurred during the 

Brunhes that perhaps accelerated rates of authigenesis. 

If the sediments can acquire a CRM or VRM over 

short time intervals, on the order of less than a few hundreds of thousands of years, the normal sediments in the 

Gauss unit may have once carried a reversed CRM acquired during the Matuyama Polarity Chronozone. During the Brunhes Polarity Chronozone, a second overprint, 

this time normal, may have effectively cancelled the 

former reversed overprint. The sediments in the Gauss 

Polarity Chronozone presently carry a single-component, 

normal remanence. 

Alternately, the remagnetization in the Matuyama 

Polarity Chronozone, and the lack of such overprint in 

the older Gauss Polarity Chronozone may be related to 

drainage incision of Onion Creek. Radiocarbon dates on 

organic material in sediments related to the incision suggest that much of the incision occurred during the past 

10,000 years. (See Physical Stratigraphy section.) 

Chemical remagnetization in the Matuyama unit may be 

due to changes in chemical conditions in the deposits 

resulting from lowering of the ground-water table with 

the drainage incision. If a change in ground-water level 

and chemistry accelerated authigenesis, recent normal 

chemical remagnetization would be most advanced in the 

uppermost reversed sediments. Both normal and indeterminate sample polarities are more common in the upper 

part of the Matuyama Polarity Chronozone than in the 

lower portion of this zone (fig. 9). Local variations in 

cementation or magnetic mineralogy of the sediments, 

which can affect rates of authigenesis, could also be 

related to the acquisition of a CRM. 

Summary 

The sediments in Fisher Valley yield a magnetic 

polarity stratigraphy which we interpret as the Brunhes, 

Matuyama, and Gauss Polarity Chronozones. Minimum 

thicknesses of the sediments deposited during the polarity chronozones are 76, 45, and 20m, respectively. The 

Brunhes-Matuyama boundary is located about 5 m below 

the Bishop ash and about 30 m below the Lava Creek 
ash. Normal polarities within the Matuyama Polarity 

Chronozone may represent normal-polarity subchronozones, but the lack of detailed independent age control 

and evidence of post-depositional remagnetization in the 

reversed zone prevent positive identification of such 

events. Polarity subzones may be delineated in such 

deposits where independent age control exists. 

The magnetic remanence in the sediments is apparently a depositional, detrital remanent magnetization 

carried primarily by specular hematite. Stability of the 

magnetic remanence appears to be related both to the 

grain size of the deposits and to local remagnetization. 

VRM and (or) CRM can apparently be acquired by such 

sediments over periods of about I m.y. or less. If our 

interpretation of the magnetic stratigraphy is correct, the 

sediments in the lower exposed basin-fill deposits have 

carried a DRM for at least 2.5 m.y. We attribute the 

preservation of the DRM in the second-cycle red 

sediments to the highly altered condition of the magnetic 

minerals prior to deposition and to the pervasive calcium 

carbonate cement in the deposits. The magnetic 

stratigraphy of the upper Cenozoic deposits in Fisher 

Valley provides an age framework for sediments that 

otherwise contain few datable materials. 

In conclusion, the stable magnetization in the Fisher 

Valley sediments demonstrates the usefulness of magnetic 

stratigraphy for dating young, second-cycle red beds. 

However, evidence of post-depositional remagnetization 

of the sediments in the reversed-polarity zone (Matuyama 

Polarity Chronozone) suggests that the preservation of 

a DRM can be variable in such deposits. 

LATE CENOZOIC DEPOSITIONAL HISTORY OF 

THE FISHER VALLEY AREA 

The upper Cenozoic sediments in Fisher Valley 

result from a long history of deposition, deformation, 

and geomorphic changes related to movement of the 

Onion Creek diapir (Colman, 1983). The physical, soil, 

and paleomagnetic stratigraphy of the Fisher Valley 

sediments form the primary record of this history. 

Mesozoic rocks arched over the crest of the Fisher 

Valley anticline probably began to collapse in late 

Miocene or early Pliocene time because of solution and 

flowage of the salt core in response to late Miocene uplift 

of the Colorado Plateau (Cater, 1970; Hunt, 1956). 

Beheaded remnants of consequent stream channels flowing away from the crest of the anticline are preserved in 

the Mesozoic rocks that form dip slopes on the northeast 

and southwest flanks of the anticline (Colman, 1983). 

Ancestral Fisher Creek headed in the igneous rocks of 

the La Sal Mountains, flowed through the collapsed crest 

of the anticline in Fisher Valley, and followed the present course of Onion Creek to the Colorado River (fig. 1). 

The Pliocene(?) gravels that contain igneous clasts from 

the La Sal Mountains must have been deposited by Fisher 

Creek against the exposed cap rock of the Onion Creek 

diapir; these gravels are the primary evidence for the 

former course of Fisher Creek (Colman, 1983). Prior to 

late Pliocene time, Beaver Creek apparently captured the 

headwaters of ancestral Fisher Creek, as late Pliocene 

basin-fill sediments deposited by Fisher Creek do not contain igneous clasts from the La Sals. 

In late Tertiary time, the Onion Creek salt diapir 

began to move upward, probably in response to unloading of overburden after anticlinal collapse, although other 

causative mechanisms may have been involved (Colman, 

1983). The upward movement of the diapir created a 

depositional basin to the east and impeded the flow of 

Fisher Creek, causing deposition and progressive deformation of a thick sequence of basin-fill sediments. 

Magnetic stratigraphy suggests that the lower basin-fill 

deposits belong to the Gauss Polarity Chronozone; if so, 

movement of the diapir began before about 2.5 m.y. ago. 

Deposition of the basin-fill sediments was controlled by 

pulses of diapiric movement and by climatic change, 

resulting in upward-fining sedimentary units interrupted 

by buried soils that indicate periods of landscape stability. 

The pattern of deformation of the deposits clearly 

shows upward movement of the diapir in an absolute 

sense (Colman, 1983) and suggests that the movement was 

punctuated by sporadic surges. The Pliocene(?) gravels 

at the base of the sedimentary sequence are sharply infolded into the cap rock with complex, near-vertical contacts (fig. 4). The lower unit of the basin-fill sediments 

dips radially away from the diapir and locally dips toward 

the valley walls in excess of 20°. The upper unit of the 

basin-fill sediments are tilted as much as 10°, also locally toward the valley walls. At least four angular unconformities along the margins of the sedimentary basin, 

coupled with concordant deposition towards the basin 

center, suggest episodic subsidence of the depositional 

basin. The overall pattern of deformation suggests 

minimum upward movement of the diapir and minimum 

subsidence of the sedimentary basin of about 70 m each, 

representing at least 140m of total differential movement 

(Colman, 1983). 

The angular unconformities along the basin 

margins mark pulses of deformation. One major angular 

unconformity separates the upper and lower units of the 

basin-fill deposits and is thus bracketed by the Lava Creek 

and Bishop ashes (0.61 and 0.73 m.y., respectively; Izett, 

1981). The well-developed buried soil (soil C) at the top 

of the lower basin-fill unit suggests that the angular unconformity is close to the Lava Creek ash in age. Other 

angular unconformities, which occur in both the upper 

and the lower basin-fill units, are at stratigraphic positions that are difficult to trace to the ashes and buried 

soils preserved near the center of the basin. Their ages 

Late Cenozoic Despositional History 21 
are thus uncertain, except for the limits provided by the 

ages of the depositional units. 

Ages estimated from the secondary carbonate content of the soil (soil I) that caps the basin-fill sediments 

suggest that deposition ended about 0.26 m.y. ago. 

Uranium-trend analyses suggest an age of about 0.24 m.y. 

ago for this event. The end of basin-fill deposition was 

probably caused by filling of the depositional basin to 

the point where Fisher Creek was diverted northeastward 

into the structural and topographic low of Cottonwood 

graben and thence to the Dolores River. Since that time, 

Onion Creek, eroding headward from the Colorado River 

along the course of ancestral Fisher Creek, has cut across 

the Onion Creek diapir and into the basin-fill sediments. 

At present, Onion Creek is within 1.5 km of capturing 

Fisher Creek and restoring it to its ancestral course. The 

only deposits in Fisher Valley younger than the basin-fill 

sediments are minor amounts of inset fluvial deposits 

(unit Qas) and Holocene alluvium and eolian sand. 

The upper Cenozoic deposits in Fisher Valley have 

recorded the history of the valley and its relation to the 

Onion Creek salt diapir. Geologic mapping and analysis 

of the physical and soil stratigraphy provided the sequence of events in the history of Fisher Valley and the 

relation of the landforms and deposits to movement of 

the diapir. Analyses of soil development and paleomagnetic stratigraphy provided most of the time framework 

into which the sequence of events fits. 

REFERENCES CITED 

Biggar, N. E., Harden D. R., and Gillam, M. L., 1981, Quaternary deposits in the Paradox Basin, in Weigand, D. L., 

ed., Geology of the Paradox Basin: Rocky Mountain Association of Geologists, 1981 Field Conference, p. 129-145. 

Birkeland, P. W., 1984, Soils and geomorphology: New York, 

Oxford University Press, 372 p. 

Carter, W. D., and Gualtieri, J. L., 1965, Geyser Creek 

fanglomerate (Tertiary), La Sal Mountains, eastern Utah: 

U.S. Geological Survey Bulletin 1224-E, p. E1-11. 

Cater, F. W., 1970, Geology of the salt anticline region in 

southwestern Colorado: U.S. Geological Survey Professional Paper 637, 80 p. 

Channel, J. E. T., 1982, Paleomagnetic stratigraphy as a correlation technique, in Odin, G. S., ed., Numerical dating 

in stratigraphy: New York, John Wiley and Sons, Ltd., 

p. 81-103. 

Chleborad, A. F., Powers, P. S., and Farrow, R. A., 1975, A 

technique for measuring bulk volume of rock materials: 

Association of Engineering Geologists Bulletin, v. 12, no. 

4, p. 317-322. 

Choquette, A. F., and Colman, S. M., 1983, Paleomagnetic 

stratigraphy of Upper Cenozoic sediments, Fisher Valley, 

southeastern Utah: Geological Society of America 

Abstracts with Programs, v. 15, p. 388. 

22 Cenozoic Sediments, Fisher Valley, Utah 

Collinson, D. W., 1965, The remanent magnetization and 

magnetic properties of red sediments: Geophysical Journal, Royal Astronomical Society, v. 10, p. 105-126. 

___ 1983, Methods in rock magnetism and paleomagnetismTechniques and instrumentation: London, Chapman and 

Hall, 503 p. 

Colman, S.M., 1983, Influence of the Onion Creek salt diapir 

on the late Cenozoic history of Fisher Valley, southeastern 

Utah: Geology, v. 11, p. 240-243. 

Colman, S.M., and Hawkins, F. F., 1985, Surficial geologic 

map of the Fisher Valley-Professor Valley area, southeastern Utah: U.S. Geological Survey Miscellaneous 

Investigations Map I-1596, scale: 1-24,000. 

Dane, C. H., 1935, Geology of the salt anticline and adjacent 

areas, Grand County, Utah: U.S. Geological Survey 

Bulletin 863, 184 p. 

Dreimanis, Aleksis, 1962, Quantitative determination of 

calcite and dolomite by using Chittick apparatus: Journal of Sedimentary Petrology, v. 32, no. 8, p. 520-529. 

Dunlop, D. J., and Sterling, J. M., 1977, 'Hard' viscous 

remanent magnetization (VRM) in fine-grained hematite: Geophysical Research Letters, v. 4, no. 4, 

p. 163-166. 

Elston, D.P., and Purucker, M. F., 1979, Detrital magnetization in red beds of the Moenkopi Formation (Triassic), 

Gray Mountain, Arizona: Journal of Geophysical 

Research, v. 84, no. B4, p. 1653-1665. 

Gile, L. H., and Grossman, R. B., 1979, The Desert Project 

soil monograph: U.S. Department of Agriculture, Soil 

Conservation Service, 984 p. 

Gile, L. H., Hawley, J. W., and Grossman, R. B., 1981, Soils 

and geomorphology in the Basin and Range area of 

southern New Mexico-Guidebook to the Desert Project: 

New Mexico Bureau of Mines and Mineral Resources 

Memoir 39, 222 p. 

Griffiths, D. H., King, R. F., and Wright, A. E., 1957, Some 

field and laboratory studies of depositional remanence of 

recent sediments: Advances in Physics, v. 6, p. 306. 

Griffiths, D. H., King, R. F., Rees, A. 1., and Wright, A. 

E., 1960, Remanent magnetism of some recent varved 

sediments: Proceedings of the Royal Society of London, 

Series A, v. 256, p. 359-383. 

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, D. R., Biggar, N. E., and Gillam, M. L., 1985, Quaternary deposits and soils in and around Spanish Valley, Utah, 

in Weide, D. L., ed., Soils and Quaternary geology of the 

southwestern United States: Geological Society of America 

Special Paper 203, p. 43-64. 

Hays, J.D., Imbrie, John, and Shackleton, N.J., 1976, Variations in the earth's orbit-Pacemaker of the ice ages: 

Science, v. 194, no. 4270, p. 1121-1132. 

Hoblitt, R. P., Larson, E. E., and Walker, T. R., 1974, 

Chemical remagnetization of Miocene red beds in southern 

New Mexico [abs.]: Eos, Transactions of the American 

Geophysical Union, v. 55, no. 12, p. 1110. 

Hunt, C. B., 1956, Cenozoic geology of the Colorado Plateau: 

U.S. Geological Survey Professional Paper 279, 99 p. 
Izett, G. A., 1981, Volcanic ash beds-Recorders of upper 

Cenozoic silicic pyroclastic volcanism in the western United 

States: Journal of Geophysical Research, v. 86, no. B11, 

p. 10200-10222. 

King, R. F., 1955, The remanent magnetism of artificially 

deposited sediments: Royal Astronomical Society, Monthly 

Notices, Geophysical Supplement, v. 7, no. 3, p. 115-134. 

Larson, E. E., 1981, Selective destructive demagnetizationAnother microanalytic technique in rock magnetism: 

Geology, v. 9, p. 350-355. 

Larson, E. E., and Walker, T. R., 1975, Development of chemical 

remanent magnetization during early stages of red-bed 

formation in late Cenozoic sediments, Baja, California: 

Geological Society of America Bulletin, v. 86, p. 639-650. 

___ 1982, A rock magnetic study of the lower massive sandstone, Moenkopi Formation (Triassic), Gray Mountain area, 

Arizona: Journal of Geophysical Research, v. 87, no. B6, 

p. 4819-4836. 

Larson, E. E., Walker, T. R., Patterson, P. E., Hoblitt, R. P., 

and Rosenbaum, J. G., 1982, Paleomagnetism of the 

Moenkopi Formation, Colorado Plateau-Basis for longterm model of acquisition of chemical remanent magnetism 

in red beds: Journal of Geophysical Research, v. 87, no. 

B2, p. 1081-1106. 

Levine, E. R., and Ciolkosz, E. J., 1983, Soil development on 

till of various ages in northeastern Pennsylvania: Quaternary Research, v. 19, no. 1, p. 85-99. 

Machette, M. N., 1978, Dating Quaternary faults in the southwestern United States by using buried calcic paleosols: U.S. 

Geological Survey Journal of Research, v. 6, no. 3, 

p. 369-381. 

Machette, M. N., 1985, Calcic soils of the American Southwest, 

in Weide, D. L., ed., Soils and Quaternary geology of the 

southwestern United States: Geological Society of America 

Special Paper 203, p. 1-21. 

Mankinen, E. A., and Dalrymple, G. B., 1979, Revised geomagnetic polarity time scale for the interval 0-5 m.y. B. P.: 

Journal of Geophysical Research, v. 84, no. B2, 

p. 615-626. 

National Oceanic and Atmospheric Administration, 1981, 

Climatic data for the United States, annual summaries: 

v. 13, 563 p. 

Patterson, P. E., 1981, Petrographic, geochemical, and paleomagnetic ·study of color banding the Cathedral Bluffs 

Tongue of the Wasatch Formation (Eocene}, Washakie 

Basin, Wyoming: Boulder, Colo., University of Colorado, 

M.S. thesis, 151 p. 

Pierce, K. L., 1979, History and dynamics of glaciation in the 

northern Yellowstone National Park area: U.S. Geological 

Survey Professional Paper 729-F, 90 p. 

Rees, A. I., 1961, The effect of water currents on the magnetic 

remanence and anisotropy of susceptibility of some 

sediments: Geophysical Journal, Royal Astronomical Society, v. 5, p. 235-251. 

Richmond, G. M., 1962, Quaternary stratigraphy of the La Sal 

Mountains, Utah: U.S. Geological Survey Professional 

Paper 324, 135 p. 

Rosholt, J. R., 1985, Uranium-trends systematics for dating 

Quaternary sediments: U.S. Geological Survey Open-File 

Report 85-298, 34 p. 

Shoemaker, E. M., 1954, Structural features of southeastern Utah 

and adjacent parts of Colorado, New Mexico, and Arizona, 

in Stokes, W. L., ed., Guidebook to the geology of Utah: 

Utah Geological Society, Guidebook 9, p. 48-69. 

Turner, P., 1979, The paleomagnetic evolution of continental red 

beds: Geological Magazine, v. 116, no. 4, p. 289-301. 

U.S. Department of Commerce, Weather Bureau, 1953, Climatic 

summary for the United States, supplement for 1931-1952, 

337 p. 

Van Houten, F. B., 1968, Iron oxides in red beds: Geological 

Society of America Bulletin, v. 79, p. 399-416. 

Verosub, K. L., 1977, Depositional and post-depositional processes in the magnetization of sediments: Reviews of 

Geophysics and Space Physics, v. 15, p. 129-143. 

Walker, T. R., Larson, E. E., and Hoblitt, R. P., 1981, Nature 

and origin of hematite in the Moenkopi Formation 

(Triassic), Colorado Plateau-A contribution to the origin 

of magnetism in red beds: Journal of Geophysical Research, 

v. 86, no. B1, p. 317-333. 

Walker, T. R., Waugh, Brian, and Crone, A. J., 1978, Diagenesis 

in first-cycle desert alluvium of Cenozoic age, southwestern 

United States and northwestern Mexico: Geological Society of America Bulletin, v. 89, p. 19-32. 

Zarr, H. E., 1974, Biostatistical analysis: Englewood Cliffs, New 

Jersey, Prentice-Hall Inc., 620 p. 

Zijderveld, J. D. A., 1967, A. C. demagnetization of rocksAnalysis of results, in Collinson, D. W., Creer, R. M., and 

Runcorn, S. K., eds., Developments in solid earth 

geophysics, v. 3, Methods in paleomagnetism: Amsterdam, 

Elsevier, p. 254-286. 

References Cited 23 

TABLES 4-6 

Descriptions and laboratory data, Fisher Valley soils 
N 

"" 

Q Table 4. Soil descriptions and laboratory data, Fisher Valley soils ~ 

~ [All soils located in section A (fig. 3), except for soil I gravelly facies, which is located near the basin margin; n.d., not determined] 

;:;· 

IJl 

I'D 

c. 

3" 

I'D 

;; 

'TI 

;:;;· 

:r 

!:e 

< 

~ 

~ 

c: 

6r 

:r 

Sample horizon1 

SJ-1 A1 

SJ-2 A1 

SJ-3 Ck1 

SJ-4 Ck2 

SI-1 Btb 

SI-2 BKb1 

SI-3 Btkb2 

SI-4 BKb 

SI-S KBb 

SI-6 Kb1 

SI-7 Kb2 

SI-8 Ckb1 

SI-9 Ckb2 

SI-10 Ck.b3 

SI-ll Ckb4 

SH-1 Btb 

SH-2 Btkb 

SH-3 Ckmb 

SH-4 2Ckb1 

SH-5 3Ckb2 

SG-1 Btkb 

SG-2 2Ckb1 

SG-3 2Ckb2 

SG-4 2Ckb3 

Depth 

(em) 

0-8 

8-18 

18-42 

42-72 

0-20 

20-43 

43-67 

Texture 2 

sl 

1 

sl 

sl 

sl 

sl 

1 

67-93 1 

93-109 sl 

109-135 sl 

135-170 sl 

170-218 sl 

218-248 sl 

248-282 sl 

282-317 sl 

Color 3 

(dry) 

5YR575 

5YR5/4 

Str~cture 4 

sg-w,vf,pl 

w,vf,pl 

2.5YR5/5 m,c,abk 

2.5YR5/5 w,m-c,abk 

5YR5/5 s,m,abk 

5YR5/6 s,f,abk 

5YR5/6 s ,m,abk 

5YR5/7 m,m,sbk 

SYR6/5 m,m,pl 

5YR8/5 m,c,pl 

5YR7/4 s,m,pl 

5YR5/6 s,c,pl5YR7/4a m,m,abk 

5YR5/5 s,m,abk 

5YR6/4a 

2.5YR5/6 m-s,m,abk 

2.SYR5/6 m,m,sbk 

0-20 

20-55 

55-80 

80-95 

95-120 

sl 2.5YR5/7 s,m,sbk 

sl 2.5YR6/5 m,c,sbk 

sl 2.5YR6/5 m 

vgls 2.5YR6/4 m,f,abk 

ls 2.5YR5/5 s,c,sbk 

0-15 sl 2.5YR4/6 m,m,abk 

15-40 vgls 2.5YR5/5 w,m,abk 

40-140 vgls 2.5YR5/5 m-sg 

140-180 vgs 2.5YR5/6 m-sg 

Weight Weight percent 0 

Carbonate percent Sand Silt 

morphology 5 gravel Coarse Fine Coarse Fine 

none 

none 

none 

none 

I 

I 

I 

IllIII 

III 

II-III 

II 

I 

I 

none 

I 

II 

II 

II 

II 

1 

none 

o.o 

.o 

.o 

.o 

o.o 

.o 

.o 

.o 

.o 

.o 

.o 

.o 

.o 

.o 

.o 

o.o 

.o 

.o 

66.1 

.o 

0.0 

70.0 

70.5 

43.1 

Soil J 

3.1 59.3 19.6 7.5 

2.0 46.6 26.3 11.~ 

3.9 65.7 20.2 

3.6 67.5 19.5 

Soil I 

2.5 58.1 19.3 

1.3 53.4 20.9 

1.0 42.5 

.9 45.8 

10.2 55.6 

10.6 53.5 

11.9 57.7 

12.4 54.9 

10.6 49.7 

12.7 49.4 

6.6 63.9 

Soil H 

5.3 61.9 

12.6 59.3 

16.8 58.9 

34.8 48.7 

31.6 49.2 

Soil G 

16.8 59.6 

42.6 38.9 

48.0 36.6 

60.9 26.4 

28.6 

28.3 

13.0 

18.2 

15.7 

21.5 

28.7 

26.1 

19.5 

20.3 

15.0 

14.3 

11.2 

12.3 

10.2 

10.4 

8.9 

7.8 

3.9 

3.8 

4.1 

5.3 

6.5 

8.8 

3.2 

3.3 

2.8 

4.0 

4.8 

4.8 

3.2 

3.9 

2.9 

2.3 

1.8 

2.1 

2.3 

2.2 

1.7 

1.5 

Clay 

Coarse Fine 

6.0 4.5 

8.6 4.7 

3.7 

3.3 

3.4 

17.0 

5.9 

2.6 

2.3 

12.6 

2.1 

15.4 

9.8 6.4 

4.2 13.9 

5.0 9.4 

2.6 9.4 

3.5 3.6 

3.2 3.0 

3.5 3.6 

3.1 3.7 

4.4 

2.8 

2.2 

1.7 

2.0 

3.1 

1.8 

1.7 

1.4 

4.2 

7.3 

5.5 

1.8 

2.8 

7.9 

4.0 

3.1 

2.0 

Total 

clay 

(g/cm3 ) 

0.15 

.19 

.09 

.08 

0.28 

.35 

.39 

.28 

.32 

.25 

.23 

.14 

.11 

.13 

.11 

0.14 

.18 

.14 

.07 

.09 

0.20 

.10 

.08 

.06 

de!~~;37 (g/cm ) 

1.4" 

1.43 

1.47 

1.43 

l. 76 

1.81 

l. 82 

1.68 

l. 72 

1.69 

l. 91 

1.89 

1.81 

1. 81 

1.62 

1.67 

1. 72 

1.84 

1.92 

1.82 

1.77 

1. 7e 

1. 7e 

1. 7e 

Percent 

Caco3 

( (2mm) 

6.7 

6.4 

8.4 

7.6 

0 .• 6 

1.2 

2.3 

3.1 

39.4 

37.0 

24.5 

18.2 

12.0 

14.4 

12.5 

5.2 

18.7 

16.2 

15.3 

9.7 

9.9 

15.4 

11.9 

11.0 

Weight 

loss on 

ignition 

2.8 

3.0 

1.4 

1.2 

1.4 

1.9 

2.3 

2.0 

2.1 

.9 

.7 

.8 

.7 

.6 

.5 

.9 

1.0 

.8 

1.2 

.5 

0.7 

.5 

.5 

.5 
> 'C 

'C 

tD 

::;, 

Cl. 

)<' 

~ 

~ 

Sample horizon1 

SF-1 Btb 

SF-2 Btkb 

SF-3 Ckb 

SF-4 Btb 

SF-5 Ckbl 

SF-6 Ckb2 

SF-7 2Ckb3 

SF-8 2Ckb4 

SE-1 Bkb 

SE-2 2Btb 

SE-3 2Btkb 

SE-4 2Ckbl 

SE-5 2Ckb2 

SE-6 2Ckb3 

SD-3 Ckbl 

SD-2 Ckb2 

SD-1 Ckb3 

SC-1 Btkbl 

SC-2 Btkb2 

SC-3 CBkb 

SC-4 Ckbl 

·sc-5 Ckb2 

SC-6 Ckb3 

Weight Weight percent 6 

Depth Texture 2 Color3 Structure4 Carbonate percent Sand Silt Clay 

(em) (dry) morphology 5 gravel Coarse Fine Coarse Fine Coarse Fine 

0-12 

12-23 

23-43 

43-60 

60-96 

sl 

sl 

sl 

sl 

sl 

2.5YR5/6 m,m,abk 

2.5YR6/6 m,m,abk 

2.5YR6/6 w,m,prm,m,abk 

2.5YR5/7 w,m,sbk 

5YR7/5 w,c,prm,m,v.bk 

96-116 sl 5YR7/5- m,m,abk 

2.5YR6/6 

116-140 vgsl 2.5YR5/5 w,m,sbk 

140-167 vgsl 2.5YR4/6 w,m,abk 

0-20 vgls 2.5YR4/6 w,f,sbk 

20-35 scl 10YR4/6 s,m,abk 

35-48 sl 2.5YR5/6 s,m,abk 

2.5YR6/6b 

48-74 sl 2.5YR6/6 s,f,abk 

74-126 sl 2.5YR6/6 m,c,pl 

126-156 1 2.5YR5/6 m 

0-40 

40-80 

0-20 

0-35 

sl 

sl 

1 

sl 

35-55 sl 

55-78 sl 

78-114 sl 

114-150 sl 

150-190 sl 

n.d. 

n.d. 

n.d. 

n.d. 

n.d. 

n.d. 

2.5YR4/6 s,m,abk 

2.5YR4/7 m,f,abk 

5YR4/6 s,m,abk 

5YR6/4b 

5YR5/4 m,m,abk 

5YR4/7 w,c,abk 

5YR4/6 w,c,abk 

I 

I+ 

IInone 

III 

IIII+ 

II 

none 

none 

II 

IIIIIIIII+ 

I+ 

I-ll 

I 

I 

IIIII 

I 

none 

o.o 

.o 

.o 

.0 

.o 

.o 

51.7 

67.4 

45.5 

.0 

.o 

.o 

.o 

.o 

0.0 

.o 

.o 

o.o 

.o 

.o 

.o 

.o 

.o 

Soil F 

3.2 52.8 

1.9 50.2 

7.7 54.0 

15.7 56.3 

.9 65.3 

11.2 62.3 

29.0 45.5 

39.6 34.9 

Soil E 

57.9 24.7 

17.1 45.4 

15.9 49.6 

14.7 49.8 

12.8 53.3 

3.6 42.2 

Soil D 

7.1 50.3 

9.2 45.6 

4.8 38.2 

Soil C 

11.1 56.1 

12.1 53.3 

8.1 49.1 

9.1 45.9 

6.7 48.9 

6.0 48.9 

25.8 

30.0 

24.7 

12.2 

20.2 

14.7 

14.0 

9.9 

7.7 

10.9 

15.9 

20.3 

20.1 

32.7 

27.4 

26.5 

36.5 

20.2 

19.2 

24.9 

28.9 

29.0 

28.4 

4.4 

4.6 

3.7 

3.0 

3.3 

2.4 

2.5 

2.3 

1.4 

2.4 

3.0 

3.2 

3.4 

7.3 

4.0 

4.8 

7.2 

4.0 

3.3 

4.5 

4.6 

4.8 

5.6 

3.8 10.0 

3.3 10.0 

3.0 6.9 

3.2 

3.6 

2.3 

2.4 

3.3 

9.6 

6.6 

7.2 

6.5 

9.9 

0.9 7.4 

3.6 20.7 

3.6 12.0 

2.2 9.8 

2.6 7.7 

4.0 10.3 

2.8 8.5 

3.0 10.8 

5.4 7.9 

4.2 

3.9 

4.4 

2.8 

3.5 

4.3 

4.3 

8.1 

8.9 

8.7 

7.0 

6.9 

Total 

clay 

(g/cm3) 

0.23 

.22 

.17 

.24 

.18 

.18 

.15 

.24 

0.17 

.46 

.29 

.23 

.19 

.24 

0.20 

.25 

.23 

0.16 

.23 

.24 

.20 

.19 

.20 

Bulk 

density7 

(g/cm3) 

1.67 

1.65 

1. 74 

1.83 

1.71 

1.84 

1.64 

1. 74 

1. 99 

1.89 

1.85 

1.87 

1.85 

1.68 

1. 79 

1.81 

1. 74 

1.87 

1.86 

1.80 

1. 76 

1.8e 

1. 79 

Percent Weight 

Caco3 

( (2mm) 

7.2 

10.1 

5.1 

.5 

25.6 

15.8 

13.8 

13.0 

7.7 

.5 

11.7 

16.6 

14.6 

11.8 

11.8 

9.1 

14.1 

3.9 

8.9 

25.1 

21.3 

15.8 

11.2 

loss on 

ignition 

1.1 

1.0 

.9 

.9 

.8 

.6 

.5 

.7 

0.5 

1.2 

1.0 

.7 

.8 

1.0 

0.8 

1.3 

1.5 

1.1 

1.1 

1.1 

1.0 

.8 

.8 
~ 

= 

("") 

~ 

:I 

0 

N 

0 

;:;· 

)€l 

c.. 

3' 

~ 

a 

~ 

.., 

iii' 

::r 

~ 

< 

~ 

~ 

c: 

~ ::r 

Table 4. Soil descriptions and laboratory data, Fisher Valley soils-Continued 

Sample horizon1 

SB-1 BAkb 

SB-2 Bkb 

SB-3 Btkb1 

SB-4 Btkb2 

SB-5 Ckb 

SA-2 BAh 

SA-3 Bwb 

SA-4 Btkb 

SA-5 Ckb1 

SA-6 Ckb2 

SA-7 Ckb3 

Depth Texture 2 Co1or3 

(em) (dry) 

0-12 

12-22 

22-40 

40-80 

80-90 

10-21 

21-41 

41-85 

85-114 

114-150 

150-170 

sl 

sl 

sl 

1 

sl 

sl 

sl 

1 

sl 

sl 

sl 

5YR4/8 

5YR5/8 

5YR5/7 

5YR5/8 

2.5YR4/7 

5YR5/8 

5YR5/7 

5YR5/8 

5YR5/7 

5YR5/7 

5YR5/8 

Weight 

Structure4 Carbonate percent Sand 

w,m,abk 

m,c,abk 

s,m,abk 

m-s,m,abk 

w,m,abk 

w,m,abk 

s,c,abk 

s,m,abk 

s ,m,abk 

m,c,abk 

w,c ,abk 

morphology 5 gravel Coarse Fine 

II 

I 

none 

none 

II 

I 

I 

I 

0.0 

.o 

.o 

.o 

.o 

o.o 

.o 

.o 

.o 

.o 

.o 

Soil B 

21.0 51.8 

24.7 47.7 

10.4 45.9 

6.1 38.2 

7.8 52.1 

3.7 

4.4 

2.2 

2.2 

2.1 

4.5 

Soil A 

68.1 

72.5 

42.5 

55.3 

51.6 

59.0 

Weight percent 6 

Silt Clay 

Coarse Fine Coarse Fine 

16.0 

17.4 

27.2 

32.7 

24.7 

17.9 

10.7 

31.7 

25.4 

27.0 

22.7 

3.0 

3.4 

5.7 

8.6 

4.4 

2.5 

1.9 

7.7 

5.3 

5.9 

4.4 

2.4 

2.3 

3.8 

4.7 

3.3 

2.3 

2.7 

4.4 

3.5 

3.5 

3.2 

5.8 

4.5 

6.9 

9.7 

7.7 

5.4 

7.8 

11.5 

8.3 

9.8 

6.3 

Soil I (gravelly facies) 

s1 

s2 

s3 

s4 

s5 

s6 

s7 

BAkb 

Btkb 

KBb 

2Kmb1 

2Kmb2 

2Kmb3 

2Ckb 

0-18 

18-38 

38-58 

58-89 

89-129 

sl 7.5YR5/6 m,m,sbk 

sl 5YR6/6 m,f ,abk 

vgsl 5YR8/4 s,m,abk 

vgs 5YR7/5 s,m,pl 

vgs 5YR7 /4 m to 

w,f,pl 

129-159 vgs 5YR7/4 m to 

w,f,pl 

159-189 vgls 2.5YR5/6 sg 

none 

IIIII 

IV 

III 

III 

none 

o.o 

.o 

58.3 

93.4 

92.8 

59.7 

50.1 

3.0 63.5 

2.8 62.4 

2.8 54.3 

n.d. n.d. 

n.d. n.d. 

46.4 44.7 

56.5 28.0 

20.2 

16.4 

23.4 

n.d. 

n.d. 

7.5 

10.9 

3.6 

4.2 

3.5 

n.d. 

n.d. 

1.2 

2.5 

3.8 5.8 

4.3 9.9 

2.6 13.4 

n.d. n.d. 

n.d. n.d. 

.1 .1 

1.3 .8 

Total 

clay 

(g/cm3) 

0.16 

.13 

.21 

.27 

.19 

0.14 

.19 

.31 

.22 

.25 

.18 

0.16 

.25 

.30 

n.d. 

n.d. 

.00 

.04 

Bulk 

density7 

(g/cm3) 

1.91 

1.91 

1. 90 

1.84 

1. 76 

1. 78 

1.80 

1. 90 

1.89 

1.89 

1.86 

1.63 

1.71 

1.87 

2.01 

2.01 

1.91 

1. 7e 

Percent 

CaC03 

(<2mm) 

11.9 

12.8 

18.6 

12.2 

10.3 

2.2 

1.0 

16.3 

9.5 

11.3 

10.3 

12.9 

20.1 

54.8 

47.6 

22.3 

18.6 

12.1 

~Horizon nomenclature from Birkeland (1983) and Guthrie and Witty (1982). 

Texture: s, sand; 1, loam; sl, sandy loam; ls, loamy sand; scl, sandy clay loam; g, gravelly, 15-35 percent gravel by weight; vg, very gravelly, 

)35 p~rcent gravel by weight. 

Weight 

loss on 

ignition 

0.9 

.8 

1.0 

1.1 

.9 

0.7 

.9 

1.3 

1.2 

.9 

.8 

2.4 

2.7 

3.5 

3.5 

2.0 

1.3 

.7 

4 Color, Munsell Color System: a, mottles; b, burrows; all others matrix. 

Structure: grade, size, type. Grade: w, weak; m, moderate; s, strong. Size: vf, very fine; f, fine; m, medium; c, coarse. Type: abk, angular blocky; 

sbk, ~ubangular blocky; pl, platy; m, massive; sg, single grain. 

6 Roman numerals are stages (Machette, 1985). 

Percentages are of sample fraction < 2mm. Grain-size intervals: coarse sand, 0.25-2.0 mm; fine sand, 0.05-0.25 mm; coarse silt, 0.01-0.05 mm; fine silt, 

~.00270;~le:~ima~~~:se clay, 0.0005-0.002 mm; fine clay, (0.0005 mm. 
;I> 

"C 

"C 

~ 

::::l 

Q. 

ii<" 

~ 

l.rJ 

Table 5. Secondary carbonate in Fisher Valley soils 

[--, not applicable] 

Less than 2 mm fraction 

Present Original2 

Weight Bulk Percent Bulk Percent Secondary 

Greater than 2 mm fraction 

Present Original2 Total 

Weight Bulk Percent Bulk Percent Secondary secondary 

Sample Horizon Thickness percent density1 Caco3 density Caco3 CaC03 percent density3 Caco3 density Caco3 Caco3 Caco3 

SJ-1 

SJ-2 

SJ-3 

SJ-4 

SI-1 

SI-2 

SI-3 

SI-4 

SI-5 

SI-6 

SI-7 

SI-8 

SI-9 

SI-10 

SI-ll 

SH-1 

SH-2 

SH-3 

SH-4 

SH-5 

SG-1 

SG-2 

SG-3 

SG-4 

A1 

A1 

Ck1 

Ck2 

Btb 

Btkb1 

Btkb2 

BKb 

KBb 

Kbl 

Kb2 

Ckbl 

Ckb2 

Ckb3 

Ckb4 

Btb 

Btkb 

Ckmb 

2Ckb1 

3Ckb2 

Btkb 

2Ckb1 

2Ckb2 

2Ckb3 

(em) (g/cm3) (g/cm3) (g/cm3) (g/cm3) (g/cm3) (g/cm3) (g/cm2) 

8 

10 

24 

30 

20 

23 

24 

26 

16 

26 

35 

48 

30 

34 

35 

20 

35 

25 

15 

25 

15 

25 

100 

40 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

33.9 

100.0 

100.0 

30.0 

29.5 

56.9 

1.4e 

1.43 

1.47 

1.43 

1. 76 

1.81 

1.82 

1.68 

1. 72 

1.69 

1. 91 

1.89 

1.81 

1.81 

1.62 

1.67 

1. 72 

1.84 

1.92 

1.82 

1. 77 

1. 7e 

1. 7e 

1. 7e 

6.7 

6.4 

8.4 

7.6 

0.6 

1.2 

2.3 

3.1 

39.4 

37.0 

24.5 

18.2 

12.0 

14.4 

12.5 

5.2 

18.7 

16.2 

15.3 

9.7 

9.9 

15.4 

11.9 

11.0 

1.4 

1.4 

1.4 

1.4 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

7.0 

7.0 

7.0 

7.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

Soil J 

-0.004 

-0.006 

.025 

.011 

Soil I 

-0.13 

-0.12 

-0.10 

-0.092 

.53 

.48 

.32 

.20 

.073 

.12 

.059 

Soil H 

-0.057 

.18 

.15 

.15 

.033 

Soil G 

0.031 

.12 

.058 

.043 

o.o 

.o 

.o 

.o 

o.o 

.o 

.o 

.0 

.o 

.0 

.o 

.0 

.o 

.o 

.o 

o.o 

.o 

.o 

66.1 

.o 

0.0 

70.0 

70.5 

43.1 

2.2 

2.2 

2.2 

2.2 

18.9 

15.1 

12.4 

17.9 

2.2 

2.2 

2.2 

2.2 

12.0 

12.0 

12.0 

12.0 

.15 

.068 

.009 

.13 

0.0 

-0.1 

.6 

.3 

-2.6 

-2.8 

-2.4 

-2.4 

8.5 

12.5 

11.2 

9.6 

2.1 

4.1 

2.1 

39.8 

-1.1 

6.3 

3.8 

2.3 

.8 

12.1 

0.5 

2.1 

2.3 

3.2 

8.1 
w 

= Table 5. Secondary carbonate in Fisher Valley soils-Continued 

n 

~ 

:I 

0 

N 

0 

;:;· 

V'l 

~ 

§' 

Sample Horizon Thickness 

(em) 

~ 

3. 

~ SF-1 Btb 12 

"'" ;: SF-2 

~ SF-3 

;:. SF-4 

~ SF-5 

C: SF-6 

;r 

::r SF-7 

SF-8 

SE-1 

SE-2 

SE-3 

SE-4 

SE-5 

SE-6 

SD-3 

SD-2 

SD-1 

SC-1 

SC-2 

SC-3 

SC-4 

sc-s 

SC-6 

Btkb 

Ckb 

Btb 

Ckb1 

Ckb2 

2Ckb3 

2Ckb4 

Bkb 

2Btb 

2Btkb 

2Ckb1 

2Ckb2 

2Ckb3 

Ckb1 

Ckb2 

Ckb3 

Btkbl 

Btkb2 

CBkb 

Ckb1 

Ckb2 

Ckb3 

11 

20 

17 

36 

20 

24 

27 

20 

15 

13 

26 

52 

30 

40 

40 

20 

35 

20 

23 

36 

36 

40 

Weight 

percent 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

43.8 

32.6 

54.5 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

Less than 2 mm fraction Greater than 2 mm fraction 

Present Original2 Present Original2 Total 

Bulk Percent Bulk Percent Secondary Weight Bulk Percent Bulk Percent Secondary secondary 

density1 Caco3 density Caco3 Caco3 percent density3 CaC03 density CaC03 CaC03 CaC03 

(g/cm3) (g/cm3) (g/cm3) (g/cm3) (g/cm3) (g/cm3) (g/cm2) 

1.67 

1.65 

1. 74 

1.83 

1. 71 

1.84 

1.64 

1. 74 

1.99 

1.89 

1.85 

1.87 

1.85 

1.68 

1. 79 

1.81 

1. 74 

1.87 

1.86 

1.80 

1. 76 

1.8e 

1. 79 

7.2 

10.1 

5.1 

.5 

25.6 

15.8 

13.8 

13.0 

7.7 

.5 

11.7 

16.6 

14.6 

11.8 

11.8 

9.1 

14.1 

3.9 

8.9 

25.1 

21.3 

15.8 

11.2 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

Soil F 

-0.024 

.023 

-0.055 

-0.14 

.29 

.15 

.082 

.082 

Soil E 

0.009 

-0.14 

.072 

.17 

.13 

.054 

Soil D 

0.067 

,021 

.10 

Soil C 

-0.071 

.022 

.31 

.23 

.14 

.056 

o.o 

.o 

.o 

.o 

.o 

.o 

51.7 

67.4 

45.5 

.o 

.o 

.o 

.o 

.o 

o.o 

.o 

.o 

o.o 

.o 

.0 

.0 

.o 

.o 

2.2 

2.2 

2.2 

9.3 

15.1 

19.2 

2.2 

2.2 

2.2 

9.3 

12.0 

12.0 

.oo 

.068 

0.16 

-0.3 

.3 

-1.1 

-2.4 

10.4 

3.0 

.9 

2.0 

13.0 

1.6 

-2.1 

.9 

4.4 

6.8 

1.6 

13.2 

2.7 

.8 

2.0 

5.5 

-2.5 

.4 

7.1 

8.3 

5.0 

2.2 

20.5 
> "C 

~ 

Q. = 

)(" 

~ 

Less than 2 mm fraction Greater than 2 mm fraction 

Present Original 2 Present Original2 Total 

Weight Bulk Percent Bulk Percent Secondary Weight Bulk Percent Bulk Percent Secondary secondary 

Sample Horizon Thickness percent density1 Caco3 density CaC03 Caco3 percent density3 CaC03 density CaC03 CaC03 CaC03 

SB-1 

SB-2 

SB-3 

SB-4 

SB-5 

SA-2 

SA-3 

SA-4 

SA-5 

SA-6 

SA-7 

sl 

s2 

s3 

s4 

s5 

s6 

s7 

(em) <..&L£m3) _ig/cm3 ) (g/cm 2~~~~~~~ __ (g/cm3) (g/cm3) . (g/cm3) (g/cm2) 

BAkb 

Bkb 

Btkb1 

Btkb2 

Ckb 

BAb 

Bwb 

Btkb 

Ckbl 

Ckb2 

Ckb3 

BAkb 

Btkb 

KBb 

2Kmb1 

2Kmb2 

2Kmb3 

2Ckb 

e, estimated. 

12 

10 

18 

40 

10 

11 

20 

44 

29 

36 

20 

18 

20 

20 

31 

40 

30 

30 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

41.7 

6.6 

7.2 

40.3 

49.9 

1.91 

1.91 

1.90 

1.84 

1. 76 

1. 78 

1.80 

1.90 

1.89 

1.89 

1.86 

1.63 

1.71 

1.87 

2.01 

2.01 

1.91 

1. 7e 

11.9 

12.8 

18.6 

12.2 

10.3 

2.2 

1.0 

16.3 

9.5 

11.3 

10.3 

12.9 

20.1 

54.8 

47.6 

22.3 

18.6 

12.1 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

Soil B 

0.083 

.10 

.21 

.080 

.037 

Soil A 

-0.11 

-0.13 

.17 

.036 

.070 

.049 

o.o 

.o 

.o 

.0 

.o 

0.0 

.o 

.o 

.o 

.o 

.0 

Soil I (gravelly facies) 

9.0 0.066 o.o 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

.20 

.88 

.81 

.30 

.21 

.062 

.o 

58.3 

93.4 

92.8 

59.7 

50.1 

2.2 

2.2 

2.2 

2.2 

2.2 

69.4 

32.0 

22.3 

21.5 

17.5 

2 Original properties (bulk density, percent Caco3) estimated from soil parent materials and young similar deposits. 

3 Estimates, based on gravel lithology. 

2.2 

2.2 

2.2 

2.2 

2.2 

12.0 

12.0 

12.0 

12.0 

12.0 

1.26 

.44 

.23 

.21 

.12 

1.0 

1.0 

3.8 

3.2 

.4 

9.4 

-1.2 

-2.6 

7.5 

1.0 

2.5 

1.0 

8.2 

1.2 

4.0 

22.0 

14.4 

9.4 

6.3 

2.7 

60.0 
Table 6. Secondary clay in Fisher Valley soils 

[n.d., not determined] 

Present 

Weight Bulk Percent 

Sample Horizon Thickness percent density1 clay 

SJ-1 

SJ-2 

SJ-3 

SJ-4 

SI-1 

SI-2 

SI-3 

SI-4 

SI-S 

SI-6 

SI-7 

SI-8 

SI-9 

SI-10 

SI-ll 

SH-1 

SH-2 

SH-3 

SH-4 

SH-5 

SG-1 

SG-2 

SG-3 

SG-4 

SF-1 

SF-2 

SF-3 

SF-4 

SF-5 

SF-6 

SF-7 

SF-8 

Al 

Al 

Ck1 

Ck2 

Btb 

Btkbl 

Btkb2 

BKb 

KBb 

Kb1 

Kb2 

Ckbl 

Ckb2 

Ckb3 

Ckb4 

Btb 

Btkb 

Ckmb 

2Ckb1 

3Ckb2 

Btkb 

2Ckbl 

2Ckb2 

2Ckb3 

Btb 

Btkb 

Ckb 

Btb 

Ckb1 

Ckb2 

2Ckb3 

2Ckb4 

(em) < 2 mm (g/cm3) 

8 

10 

24 

30 

20 

23 

24 

26 

16 

26 

35 

48 

30 

34 

35 

20 

35 

25 

15 

25 

15 

25 

100 

40 

12 

11 

20 

17 

36 

20 

24 

27 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

33.9 

100.0 

100.0 

30.0 

29.5 

56.9 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

43.8 

32.6 

1.4e 

1.43 

1.47 

1.43 

1. 76 

1.81 

1.82 

1.68 

1. 72 

1.69 

1.91 

1.89 

1.81 

1.81 

1.62 

1.67 

1.72 

1.84 

1.92 

1.82 

1.67 

1.65 

1. 74 

1.83 

1.71 

1.84 

1.64 

1. 74 

32 Cenozoic Sediments, Fisher Valley, Utah 

Soil J 

10.5 

13.3 

6.3 

5.6 

Soil I 

16.0 

19.1 

21.3 

16.2 

18.1 

14.4 

12.0 

7.1 

6.2 

7.1 

6.8 

Soil H 

8.6 

10.1 

7.7 

3.5 

4.8 

Soil G 

11.0 

5.8 

4.8 

3.4 

Soil J 

13.8 

13.3 

9.9 

12.8 

10.2 

9.5 

8.9 

13.2 

Original2 

Bulk Percent Secondary 

density clay 

(g/cm3) 

1.4 

1.4 

1.4 

1.4 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

5.0 

5.0 

s.o 

5.0 

6.2 

6.2 

6.2 

6.2 

6.2 

6.2 

6.2 

6.2 

6.2 

6.2 

6.2 

3.5 

3.5 

3.5 

3.5 

3.5 

3.4 

3.4 

3.4 

3.4 

8.9 

8.9 

8.9 

8.9 

8.9 

8.9 

8.9 

8.9 

0.077 

.12 

.023 

.010 

0.18 

.25 

.29 

.17 

.21 

.14 

.13 

.035 

.013 

.029 

.011 

0.088 

.12 

.086 

.011 

.031 

0.14 

.044 

.Of7 

.003 

0.088 

.077 

.030 

.092 

.032 

.032 

.004 

.087 

Total 

secondary 

clay 

(g/cm2) 

0.6 

1.2 

.6 

.3 

2.7 

3.6 

5.8 

7.0 

4.4 

3.4 

3.6 

4.6 

1.7 

.4 

1.0 

.4 

35.9 

1.8 

4.2 

2.1 

.1 

.8 

9.0 

2.1 

.3 

.8 

.1 

3.3 

1.1 

.8 

.6 

1.6 

1.2 

.6 

.1 

.8 

6.8 
Table 6. Secondary clay in Fisher Valley soils-Continued 

Present 

Weight Bulk Percent 

Sample Horizon Thickness percent density1 clay 

SE-1 

SE-2 

SE-3 

SE-4 

SE-5 

SE-6 

SC-1 

SC-2 

SC-3 

SC-4 

sc-s 

SC-6 

SB-1 

SB-2 

SB-3 

SB-4 

SB-5 

SA-2 

SA-3 

SA-4 

SA-5 

SA-6 

SA-7 

Bkb 

2Btb 

2Btkb 

2Ckb1 

2Ckb2 

2Ckb3 

Btkbl 

Btkb2 

CBkb 

Ckbl 

Ckb2 

Ckb3 

BAkb 

Bkb 

Btkbl 

Btkb2 

Ckb 

BAb 

Bwb 

Btkb 

Ckb1 

Ckb2 

Ckb3 

(em) ( 2 mm (g/cm3) 

20 

15 

13 

26 

52 

30 

35 

20 

23 

36 

36 

40 

12 

10 

18 

40 

10 

11 

20 

44 

29 

36 

20 

54.5 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

1. 99 

1.89 

1.85 

1.87 

1.85 

1.68 

1.87 

1.86 

1.80 

1. 76 

1.8e 

1. 79 

1.91 

1.91 

1.90 

1.84 

1. 76 

1. 78 

1.80 

1.90 

1.89 

1.89 

1.86 

Soil E 

8.3 

24.3 

15.6 

12.0 

10.3 

14.3 

Soil C 

8.5 

12.0 

13.3 

11.5 

10.5 

11.2 

Soil B 

8.2 

6.8 

10.7 

14.4 

11.0 

Soil A 

7.7 

10.5 

15.9 

11.8 

13.3 

9.5 

Original2 

Bulk Percent Secondary 

density clay 

(g/cm3) 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

9.0 

0.021 

.32 

.15 

.080 

.047 

.096 

0.015 

.079 

.095 

.058 

.045 

.056 

0.013 

.000 

.059 

.12 

.050 

0.00 

.045 

.16 

.079 

.11 

.033 

Soil I (gravelly facies) 

sl 

s2 

s3 

s4 

sS 

s6 

s7 

BAkb 

Btkb 

KBb 

2Kmb1 

2Kmb2 

2Kmb3 

2Ckb 

1 e, estimated. 

18 

20 

20 

31 

40 

30 

30 

100.0 

100.0 

41.7 

6.6 

7.2 

40.3 

49.9 

1.63 

1.71 

1.87 

2.01 

2.01 

1.91 

1. 7e 

9.6 

14.2 

16.0 

n.d. 

n.d. 

.2 

2.1 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

1.6 

2.0 

2.0 

2.0 

2.0 

2.0 

2.0 

2.0 

0.12 

.21 

.27 

n.d. 

n.d. 

.000 

.004 

Total 

secondary 

0.2 

4.8 

2.0 

2.1 

2.4 

2.9 

14.4 

o.s 

1.6 

2.2 

2.1 

1.6 

2.2 

10.2 

0.2 

.o 

1.1 

4.8 

.5 

6.6 

0.0 

.9 

7.0 

2.3 

4.0 

• 7 

14.9 

2.2 

4.2 

2.3 

n.d. 

n.d. 

.0 

.1 

8.8 

2 Original properties (bulk density, percent clay) estimated from soil parent materials and young 

similar deposits. 

Appendix 33 

* U.S. GPO: 1988 573-047 /66-CJ91