Lake Bonneville: 

Geology of 

Northern Utah Valley 

Utah

GEOLOGICAL SURVEY PROFESSIONAL PAPER 257-A
Lake Bonneville: 

Geology of 

Northern Utah Valley 

Utah

By C. B. HUNT, H. D. VARNES, and H. E. THOMAS

GEOLOGICAL SURVEY PROFESSIONAL PAPER 257-A

Stratigraphic, engineering, and water studies 

of part of the basin of Lake Bonneville^ 

one of the great Pleistocene lakes in the 

Western United States

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1953
UNITED STATES DEPARTMENT OF THE INTERIOR 

Douglas McKay, Secretary

GEOLOGICAL SURVEY 

W. E. Wrather, Director

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington 25, D. C. - Price $2.25 (paper cover)
CONTENTS

Abstract. __-_-_--__-_---___---______________.-..___

Introduction __--_----__--___-_-____________________

Acknowledgments __ __ _ _-------____________.___

Field work and methods. _ _______________________

Previous studies. _____ __________________________

Economic geography. _______________________________

Towns __ _ --__-_---_--____-__-________________

Agriculture __ _ __--_--_ — --__.________________

Industry _ _ ___________________________________

Transportation _________________________________

History of settlement and develop ment____ ________

Physical geography. ___________________ __ _________

Landf orms_ ____________________________________

Climate __ __----__--___--_---______-__________

General geology, by C. B. Hunt- _____________________

Stratigraphy ___________________________________

Source rocks in adjoining mountains— _________

Pre-Cambrian, Paleozoic, and Mesozoic

Tertiary ( ?) rocks _______________________

Little Cottonwood stock. ____________

Lavas and water-laid volcanics _______

Quaternary deposits in the mountains.

Glacial deposits __ _ ________________

Alluvial and other surficial deposits. __

Some relationships between the source rocks and

valley sediments. _________________________

Deposits in Utah Valley_-__---____-____-____

Salt Lake formation (Tertiary) ___________

Pre-Lake Bonne ville deposits (Pleistocene) __ 

Exposed deposits ___________________

Concealed deposits. _ ________________

Lake Bonneville group. _ _______________

Alpine formation. _ __________________

Gravel member_________________

Sand member_-______-________-

Silt and clay member _ _________

Bonneville formation. _______________

Prove formation. ___________________

Gravel member,. _ ____-______-_-

Sand member. _________________

Silt member______________._____

Clay member___________________

Concealed Pleistocene deposits.-—--------

Glacial deposits _ _ _____________________

Moraines. _________________________

Glacial outwash____________________

Alluvial deposits of Provo(?) age. ________

Post-Pro vo deposits (Pleistocene? and 

Recent) ____--_-----_________________

Alluvial deposits. _ __________________

Eolian(?) silt____ ___________________

Lake deposits. _____________________

Vertebrate fossils__ _ ________________

Page Page

1 General geology, by C. B. Hunt—Continued

2 Some geochemical problems-___-_-___-_____-----_ 31

2 Analyses and outline of some of the problems __ 31

4 Comparisons between similar deposits from dif5 ferent sources.___-_____-_-- — ___________ 32

5 Comparisons between similar deposits of dif5 ferent age______________________________ 33

5 Comparisons between near-shore and offshore

5 deposits.._______________________________ 33

5 Utah Lake-.------------.----------------- 34

5 Traces of heavy metals._____________________ 34

6 Salinity of Lake Bonneville__--_--_-_--_----_ 34

6 Calcium carbonate deposits__________________ 35

8 Comparative volumes of the formations—— _______ 36

11 Depth of the valley fill.____________ — ----- 37

11 Structural geology.______________-__-_-_----____ 38

11 Geological history_____________________________ 39

	Origin and structural history of the valley. _ ___ 39

11 History of sedimentation in the valley—______ 40

12 Lake Bonneville—a Wisconsin lake_——______ 41

12 Evolution of the climate, topography and soils. 42

12 An estimate of the geologic time and rate of

12 erosion represented by the formations.______ 43

12 Relation of the geology to some soil problems. _____ 43

12 Ancient soils_-----_-------_-------__------- 43

	Modern soils-_----__-----_-_------------__- 45

12 Saline soils___________-___-_-_-_--__----_- 45

13 Pleistocene history as a factor in soil genesis. _ _ 45

13 Some geological aspects of erosion and flood control

14 problems_____________-____--_____--_-___--_ 46

14 Engineering geology, by Helen D. Varnes______________ 47

15 Foundation materials_______--_-______---_-___ 48

17 Bench gravel___-------_--__-------------__- 49

17 Permeability and drainage_______________ 49

17 Stability___________________________ 49

18 Workability..--------________________ 49

20 River gravel_____________________________ 49

20 Permeability and drainage _______________ 50

21 Stability—.---.-------------_______ 50

21 Workability—.--------------------.--.- 50

22 Mixed gravel and sand.____________-----___- 50

23 Permeability and drainage____-____-_--__ 50

24 Stability-._____.__--__---_-._______ 50

25 Sand________________________________ 50

27 Permeability and drainage _______________ 50

27 Stability.-.-.-.______________________ 50

28 Silt and clay_.___________________________ 50

28 Permeability and drainage _______________ 50

28 Stability___________-__-____--_-_-_-_ 52

	Workability________________________ 52

28 Unsorted materials (alluvial fan deposits)_.____ 52

29 Permeability and drainage_______________ 52

29 Stability—.__________________________ 52

29 Workability.---.------------.---------- 52
IV CONTENTS

Engineering geology, by Helen D. Varnes—Continued 

Foundation materials—Continued

Consolidated rocks__-_______-______________-

Tertiary formations.____________________

Paleozoic formations. ___________________

Construction materials (unprocessed)______________

Bench gravel__-___-_-__-_______-__-___--_-_

Concrete aggregate____________________

Surfacing and base-course materials_______

Fill_ __________________________________

Riprap-_______________________________

River graveL_._____________________________

Concrete aggregate....___________________

Surfacing and base-course materials_______

Fill, __________________________________

Riprap ________________________________

Mixed gravel and sand- _____________________

Concrete aggregate..-___________________

Surfacing and base-course materials_______

Fill, ______________________________

Sand__ ________________________________

Fine aggregate _________________________

Surfacing and base-course materials_______

Fill_ __________________________________

Silt and clay_ ______________________________

Fill_ __*________________________________

Binder material-..-____-__-___-_________

Unsorted materials (alluvial-fan deposits) ______

Concrete aggregate, surfacing, and basecourse. ______________________________

Fill_ __________________________________

Riprap---_____-__-___--__--__---__---_

Consolidated rocks____-____-_-______________

Tertiary formations.____________________

Paleozoic formations____________________

Concrete aggregate, base course, surfacing, and fill.___________________

Riprap ____________________________

Limestone for flux __________________

Canal lining______________________

Construction materials (processed)________________

Clay and shale_____________________________

Lake silt and clay_--____-_-____--__-__-_

Paleozoic shale_________________________

Clay developed on ancient soils, by C. B. 

Hunt, A. S. Creamer, and J. J. Fahey___ 

Calcareous tufa (travertine)__________________

Calcite_.______________________________

Seismic activity in Utah Valley___________________

Water resources, by Harold E. Thomas._-.__________-_

Introduction ___________________________________

History of water utilization______________________

Diversions from streams_____________________

Use of water prior to 1880_____________-_

Status in 1903________________________

Status in 1947________________________

Development of wells-----___-_-___-_-_______-

Early history___________________________

Status in 1903__________-_-_--_-________

Status in 1947_____-__---_-_-__-__-_-_-_

Page Page 

Water resources, by Harold E. Thomas—Continued

	History of water utilization—Continued 

52 Reservoir control. _-____-___--__--------_--- 65

52 UtahLake____-__--__-----_---_-_------ 65

53 Deer Creek reservoir-_________-_-____--- 66

53 Other reservoirs. _______________________ 66

53 Fluctuations in water supply___------------------ 66

53 Streams---__-_-_-------_------_------_---- 66

53 Records of stream discharge._____________ 67

53 Estimates of surface inflow to northern

53 Utah Valley_--_____--_----_--__------ 68

56 Reservoirs----_-_---_---_--_----_-----_---- 69

56 Utah Lake__-__--_______--_-_-_--_-_--_ 69

56 Empirical determinations of natural

56 loss and inflow--- ________________ 69

56 Deficiencies in basic data_ ___________ 71

56 Evaporation..-______-_--_-__-- 71

56 Surface inflow-_________________ 71

56 Subsurface inflow_____-_--___-__ 71

56 Deer Creek reservoir._______„___________ 73

57 Wells--_-__-__--__--___-_------_-_--------- 73

57 Discharge from wells____________________ 73

57 Fluctuations of water level and artesian

57 pressure__-_-_____------_-_-------__- 77

57 Seasonal fluctuations._______________ 77

57 Long-term fluctuations ______________ 77

57 Relation between fluctuations of water

57 level and total well discharge_______ 78

	Springs and drains._________________________ 78

57 Sources of ground water-________________________ 79

57 Post-Provo alluvial deposits-_______-_-____--- 79

57 Water table--_-----__-----_-_--_------- 80

57 Recharge area.____--__-______-______--- 80

57 Movement and natural disposal __________ 80

57 Consumptive use_ ______________________ 80

	The problem of pollution ________________ 80

57 Lake Bonneville group______________________ 81

58 Water table-_-------_---------_____ 81

58 Recharge area__^_________________-_____ 81

58 Movement and natural disposal __________ 81

58 Consumptive use__________--_-__-___--_ 81

58 Pre-Lake Bonneville Pleistocene deposits__-___ 82

58 Shallow Pleistocene artesian aquifer. ______ 83

58 Piezometric surface----------------- 83

	Consumptive use___________________ 83

58 Deep Pleistocene artesian aquifer.________ 84

60 Piezometric surface_-_____----___--_ 84

60 Consumptive use______________--___ 84

60 Recharge areas__-__-_________---______- 84

60 Movement and natural disposal__________ 85

60 Tertiary and Tertiary (?) deposits.-_-_-____-__ 85

61 Characteristics of developed aquifer.______ 86

61 Discharge test of well (D-6-2) 8 bcd-4____ 86

61 Source and movement of water in Ter62 . tiary(?) aquifers_____---_________-____ 87

63 Water from deep sources_____________________ 89

63 Chemical quality of water.______________________ 89

63 Maximum potential development of water resources, 90

64 Selected bibliography______________________________ 92

64 Index______ ——— _- — _- — _——. — -_- —— ———— -- 97
CONTENTS

ILLUSTRATIONS

Page 

PLATE 1. Geologic map of northern Utah Valley, Utah County, Utah.______________________-______-_--------_.—- In pocket

2. Engineering geologic map of northern Utah Valley_____________________________________________________ In pocket

3. Map of northern Utah Valley showing contours on the piezometric surfaces of artesian aquifers in April 1947,

and contours on the water table under the Provo and Highland benches in June 1947_ ___________________ In pocket

4. Geologic sections in northern Utah Valley, Utah____________________________________-____---------_-_-- In pocket

FIGURE 1. Index map of Lake Bonneville showing the areas being restudied and mapped___-____-_-____-_-__--------__ 3

2. Block diagram of northern Utah Valley. View north__________________________________________________ 7

3. Rainfall map_-__________.________________________________________________________'____________----•-_ 8

4. Shapes of sand grains.-______-__________________________________-_____-_--_-_-_-____------------------ 15

5. Logs of wells at Geneva Steel plant___________________________________________________________________ 16

6. Pattern of gravel beds in Alpine formation at Geneva Steel plant_______________-_-_-_-_-------_---------- 19

7. Contour map showing configuration of the base of the clay member of the Provo formation. _________________ 21

8. Diagrammatic section along Dry Creek at Alpine_____________-__________-_--------_-__--_-------_------ 28

9. Sketch map showing location of samples collected for chemical analyses.___________________________________ 30

10. Diagrammatic section to illustrate some relationships between the geology and soil development-_____________ 44

11. Cross section showing bedding in delta front______________________-___-______________-----_----_----_- 48

12. Cross section showing bedding in post-Provo river-laid gravel deposits_____________________________________ 49

13. Mechanical analyses of silt and clay in northern Utah Valley._________________________-.-----_--_---_---_- 51

14. Map showing location of pits and quarries in northern Utah Valley_-______________________________________ 54

15. Map showing differences in types of gravel in northern Utah Valley--_____________________________________ 55

16. Hydrographs showing discharge of American Fork River and South Fork of Provo River, and increase in flow

of Provo River below Vivian Park__ ________________________________________________________________ 68

17. Correlation of stages of Utah Lake with precipitation and with inflow and outflow of the lake. _______________ 70

18. Hydrographs of four wells in northern Utah Valley._____________________________________________________ 76

19. Artesian aquifers of Pleistocene pre-Lake Bonneville deposits._______________-_-__---____----___-___------ 77

20. Monthly discharge from three spring areas in northern Utah Valley, 1937-40._____________-_--_----__-_____ 79

21. Discharge and drawdown during test of well (D-6-2)8bcd-4, April 16, 1948-_______________________________ 86

22. Chemical analyses of water from wells of the Geneva Steel Co_ ___________________________________________ 88

TABLES

TABLE '1. Annual precipitation at weather stations in or near northern Utah Valley______--_-_________________________ 9

2. Average monthly and annual precipitation at weather stations in or near northern Utah Valley________________ 10

3. Average evaporation_________________________________________________________________________________ 10

4. Complete analyses of silt and clay from Provo formation northwest of Dry Creek.___________________________ 31

5. Complete analyses of silt and clay from Provo formation southeast of American Fork River___________________ 31

6. Complete analyses of silt and clay from Alpine formation.________________________________________________ 31

7. Analyses of water-soluble salts in Alpine and Provo formations_____________________^_______________________ 32

8. Analyses of water from Utah Lake.____________________________________________________________________ 32

9. Proportions of certain constituents in the Provo formation in different parts of the valley____-___________---__ 32

10. Proportions of water-soluble salts in the Provo formation in different parts of the basin.______________________ 32

11. Proportions of certain constituents in lake-bottom deposits of parts of Provo and Alpine formations that had a

common source.___________________________________________________________________________________ 33

12. Proportions of water-soluble salts in the Provo and Alpine formations. _____________________________________ 33

13. Distribution of water-soluble salts in silt and clay facies of the Alpine formation.____________________________ 33

14. Distribution of water-soluble salts in silt and clay facies of the Provo formation_____________________________ 33

15. Traces of heavy metals in Provo and Alpine formations.._________________________________________________ 34

16. History of principal stream diversions prior to 1880 in northern Utah Valley_ _______________________________ 61

17. Classifications of wells in northern Utah Valley in 1947-__________________________________________________ 64

18. Number of wells in northern Utah Valley by years.___-__-______________-_-__--------_____------____----- 65

19. Stream-discharge records for northern Utah Valley.______________________________________________________ 67

20. Estimated surface inflow to northern Utah Valley._______________-_-_---_____-__---_____------_----__-_-- 69

21. Annual changes in storage, inflow, and outflow of Utah Lake______________________________________________ 71

22. Surface inflow to and discharge from principal alluvial fans of northern Utah Valley__________________________ 72

23. Water yielded annually by wells in Highland district, 1938-40_____-_____________---_-__-_----_-__---_---_- 73

24. Water yielded annually by wells in Provo district, 1938-40____________________-__________----------__----- 75

25. Changes of water levels in observation wells________________________________________________________-___- 78

26. Multiple-step drawdown test of Geneva Steel Co. well (D-6-2) 8bcd-4, April 16, 1948—-_--_---____--___----- 86

27. Mineral content and hardness of water in streams, and in aquifers of different depths at Geneva, Utah_________ 87

28. Annual inflow to Utah Lake at Geneva Steel plant___________________________-_-___-_____------_--___---- 92

LAKE BONNEVILLE: GEOLOGY OF NORTHERN UTAH VALLEY, UTAH

By CHARLES B. HUNT, HELEN D. VARNES, and HAROLD E. THOMAS

ABSTKACT

Lake Bonneville was a vast Pleistocene lake that covered 

20,000 square miles in northwestern Utah and had a maximum 

depth of about 1,000 feet. It was a body of water comparable 

in size to modern Lake Michigan.

Surveys of the unconsolidated deposits in the Lake Bonneville 

basin utilize the same methods used in studies of hard rocks, 

namely: separation of the deposits into mappable units and

contacts between formations; observations of lateral and vertical 

changes in lithology; and plotting of these data on the map.

The sedimentary deposits in Utah Valley were derived from 

the adjoining mountains which are composed very largely of 

limestone and quartzite but include some granite and extrusive 

rocks. The stratigraphy of the deposits in northern Utah

determination of their stratigraphic sequence; lateral tracing of Valley is summarized as follows:

Tertiary and Quaternary formations in northern Utah Valley

Post-Provo deposits. Mostly uncemented fanglomerate, alluvial gravel or alluvial sand; some eolian(?) 

silt and thin lake deposits. Maximum thickness about 50 feet.

.Unconformity________________________________________________ 

Provo formation. An extensive gravel member, as much as 50 feet thick, occurs in deltas 

and embankments; a thinner and less extensive sand member occurs as facies in the 

deltas and forms bars in front of them; a silt member and a clay member comprise 

the deep-water deposits, but they generally are less than 20 feet thick.

Lake Bonneville group

_Unconformity ?____ 

Bonneville formation. 

_Unconformity ?.

Gravel and sand, restricted to embankment deposits.

Alpine formation. Mostly silt and clay; some gravel and sand near canyon mouths.

Maximum thickness about 25 feet. 

_Unconformity.

Pre-Lake Bonneville deposits (glacial, lacustrine, and fluvial). Includes at least one moraine of pre-Lake 

Bonneville age. Includes deposits of several lakes that, in size and duration, apparently 

were comparable to Lake Bonneville; these lake deposits are separated by fanglomerate 

and other fluviatile deposits. Total thickness 680 feet or more.

___________Unconformity_______________________________________________

Salt Lake formation. Water-laid pyroclastics, fanglomerate.

>, §a

aUtah Valley is a structural valley bounded by faults and undoubtedly is the result of faulting primarily, although folding 

or tilting may have contributed to the displacement. Rocks in 

the mountains around the valley are intensely deformed, largely 

because of the folding, overthrusting, and other faulting that 

occurred during the Cretaceous and probably also during early 

Tertiary time. The valley, however, is largely the product of 

later structural movements that gave rise to block faulting.

These later movements apparently began in middle or late 

Tertiary time and continued intermittently throughout Quaternary time. The earliest record of sedimentation in the valley 

is represented by the tuffs, related volcanics, and other sediments of the Salt Lake formation. During Pleistocene time 

several lakes comparable in magnitude to Lake Bonneville, but 

earlier, flooded the valley. These lakes presumably correlate 

with the early glacial periods. The faults that bound the valley

displace these early Pleistocene deposits less than the Tertiary 

deposits, and more than the Lake Bonneville group.

Lake Bonneville was a product of the last glacial period and 

is believed to be of Wisconsin age. Outwash from the youngest 

moraine at the mountain front is interbedded with the Lake 

Bonneville group. The earliest deposits of the Lake Bonneville 

group, the Alpine, which is composed chiefly of clay and silt, is 

believed to represent the erosion of an ancient and deep soil 

from the mountains. The younger formations, which contain 

a higher proportion of rock fragments, apparently record a 

change of climate that resulted in erosion becoming dominant 

over weathering in the mountains.

The record of the several glaciations in the mountains and of 

the several lakes in the valleys clearly shows wide fluctuations of 

past climates. The rates of erosion and sedimentation under 

the different climates are not known, but one fact does become
LAKE BONNEVILLE

apparent—either the rates of erosion and sedimentation in the 

past must have exceeded by several times the rates since Lake 

Bonneville time, or the Pleistocene epoch must have been 

several times longer than generally has been thought.

The fluctuations in climate that are recorded in the geology 

are also recorded in the soils of the area. Some ancient soils 

that formed in pre-Lake Bonneville time have been recognized. 

These are wholly different from modern soils. The ancient soils 

are as deep as 30 feet; they consist of an upper layer of limefree illitic clay and an underlayer of weathered parent material 

that is strongly lime-impregnated. The modern soils have only 

feebly developed profiles and rarely are more than a very few 

feet deep. In the ancient soils the parent material is entirely 

altered to clay in the upper layers; in the modern soils the alteration consists of little more than a slight transfer downward of 

water-soluble salts, and the parent material still dominates all 

layers in the profile.

A considerable number of chemical analyses of the Lake 

Bonneville sediments were made in the Chemistry Laboratory 

of the U. S. Geological Survey. Some of the principal relationships brought out by the analyses are the following:

1. There is considerable similarity in the chemical composition of contemporaneous deep-water deposits that had different 

sources, indicating that the rate of settling of sediment in the 

deep-water parts of the lake was sufficiently slow to permit 

rather thorough mixing of the sediments.

2. The content of water-soluble salts in the younger of the 

Lake Bonneville group (Provo formation) is considerably greater 

than in the older deposits (Alpine formation), evidently indicating that Lake Bonneville became increasingly saline as it 

diminished in size.

3. The quantity of water-soluble salts increases shoreward in 

the older of the Lake Bonneville group (Alpine formation), 

whereas it decreases shoreward in the younger deposits (Provo 

formation).

Calcium carbonate deposits in Utah Valley are of at least four 

kinds: spring deposits, deposits at headlands in the old lake 

evidently derived from the lake waters, deposits at the top of a 

fluctuating water table, and deposits formed by soil processes.

Adequate data on the kind and distribution of the earth 

materials that make up Utah Valley facilitate the location of 

construction materials such as gravel, sand, and riprap, and can 

be used in making preliminary estimates on excavation and fill 

requirements. Subsidence of foundations and roads, excessive 

leakage in irrigation ditches, and similar problems are directly 

tied to the geologic environment; hence, knowledge of the 

geology affords an explanation of the source of these troubles in 

the case of already existing structures and makes it possible to 

foresee and prevent them in new construction.

The manner in which materials are used largely determines 

which of their properties are significant. A description of the 

engineering geology summarizes the engineering properties 

of the formations in three categories: foundation materials; 

construction materials that are unprocessed except by screening 

or washing; and construction materials that are processed in 

some manner, such as the burning of clay for brick or tile, or the 

dressing of building stone.

The chapter on water resources reviews the history of water 

utilization and describes what is known about the fluctuations in 

the water supply, both as to surface water and ground water. 

The principal developed sources of ground water in the valley 

are the pre-Lake Bonneville Pleistocene deposits. Important 

sources also have been developed in older, possibly Tertiary, 

deposits. Small amounts are developed also from the Lake 

Bonneville and younger deposits.

INTRODUCTION

The intermontane valleys in the Basin and Range 

province have received little study and probably are 

the least known geologically of any valleys in the 

United States. Yet a wealth of Quaternary and 

Tertiary stratigraphic and structural history can be 

gleaned from these valleys, for they contain the positive 

depositional record of the periods that in the mountains 

are represented by erosion.

A comprehensive and classic study of the whole 

Bonneville Lake basin was made by G. K. Gilbert 

during the latter part of the last half century, but his 

methods were necessarily of a reconnaissance nature. 

In 1946, the U. S. Geological Survey began a series of 

detailed studies in order to map the basin systematically and to obtain fuller information about its geological 

history and resources. This report, together with the 

accompanying map, covers that part of the Bonneville 

Lake basin lying in the north half of Utah Valley, an 

area embracing about 150 square miles (fig. 1), and is 

the first of a series of studies of Lake Bonneville.

The work was undertaken largely as an experiment 

to develop methods and techniques for mapping poorly 

exposed unconsolidated deposits. As the work progressed, it became increasingly evident that mapping 

unconsolidated deposits in an area like Utah Valley is 

no different from mapping poorly exposed hardrock 

formations. The methods and techniques used are 

described in a following section of the report.

Probably the most important contribution of this 

experimental study is that it has provided impetus to 

a program for the systematic mapping of the Lake 

Bonneville, Lake Lahontan, and other basins in the 

Basin and Range province. Encouraged by the results of the Utah Valley investigation, the Geological 

Survey has undertaken similar projects in adjoining 

areas and similar work has been started in the Lahontan 

Basin. It is hoped that these are but the first of a 

series of reports leading to the complete systematic 

mapping that is so much needed in these old basins.

ACKNOWLEDGMENTS

The members of the Geology Departments at the 

University of Utah, Brigham Young University, and 

Utah State Agricultural College provided much stimjilation and encouragement during the study. Their 

interest and cooperation were of material assistance, as 

were the facilities that they made available in connection with the field studies.

During the field work much pleasure and profit was 

derived from field conferences with numerous members 

of the U. S. Geological Survey; their criticisms and 

suggestions were most helpful, especially those of A. A. 

Baker, who has been studying and mapping in the
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH

. Northern Utah 

2.Southern Utah

3.Cache Valley

4. Pavant Valley

5.. Oak City

FIGURE 1.—Index map of Lake Bonneville showing the areas being restudied and mapped. 1. Northern Utah Valley; 2. Southern Utah Valley; 3. Cache Valley; 4. Pavant

Valley; 5. Oak City area.

247743—54———2
LAKE BONNEVILLE

Wasatch Range east of Utah Valley, and Roger B. 

Morrison, who has been mapping and studying the 

Carson Sink area in the Lake Lahontan Basin, Nevada.

Geoffrey B. Bodman, of the Division of Soils, College 

of Agriculture, University of California, spent 3 days 

in the area in connection with some of the soils problems, 

and he has contributed analyses as well as many helpful 

criticisms and suggestions about that phase of the study.

Personnel of the Pleasant Grove office of the Bureau 

of Reclamation were very cooperative and contributed 

much data useful in the chapter on engineering geology. 

Mr. Richard Van Horn assisted both in the field and 

office during the summer and winter of 1947, especially 

in connection with the engineering geology study. 

Mr. David Varnes assisted in this phase of the study 

also for about 3 weeks in 1947.

FIELD WORK AND METHODS

The field work for this report was done intermittently 

during the period January 1946 to September 1947.

Fortunately there was available an excellent topographic map which served as a base. This map, 

surveyed in 1922 and 1925 by the Geological Survey in 

cooperation with Utah County and the Bureau of 

Reclamation, is on a scale of 1:24,000; it has a contour 

interval of 5 feet except near the lake where the contours 

were surveyed at 1-foot intervals. Without this excellent base, the geologic mapping in Utah Valley would 

have been slow, tedious, and much more costly. In 

addition to the base map there were available some 

aerial photographs covering the edges of the valley.

The mapping of unconsolidated deposits like those 

in Utah Valley involves the same principles as does the 

mapping of bedrock formations. Separation of the deposits into mappable units, superposition of beds, 

lateral tracing of contacts between formations, observations of lateral and vertical changes in lithology, and 

plotting of these on the map are the cardinal principles 

that must be followed.

In a basin like Utah Valley good outcrops are few, 

and in many places the position of the formation 

boundaries must be inferred. Accurate mapping, 

therefore, would require extensive trenching or augering, but such work was not possible during the study. 

In lieu thereof it generally was necessary to infer the 

positions of contacts and in some places even to infer 

the nature of the lithology of the formation by mustering every kind of evidence that could be brought to 

bear on the problem.

In the absence of outcrops the most useful tool for 

this kind of mapping is soil texture and composition, 

especially where the soils are feebly developed or immature. Variations in ground drainage conditions, 

such as the distribution of seeps, throw light on the

geology. Landform is another valuable tool. For purposes of geologic mapping none of these is exact but the 

collective evidence such observations furnish plus occasional outcrops are sufficient to reveal the principal 

elements in the geologic pattern. Contacts traced 

laterally by following variations in soil or ground 

drainage generally lead the observer to exposed contacts that reveal the lateral relationship and relative 

age of the deposits being traced.

The mapping of gradational or poorly exposed formation boundaries commonly is difficult and is especially difficult in deposits like these. For example, the 

pre-Lake Bonneville deposits below 5,100 feet in altitude were reworked by the waves and currents of the 

old lake. What degree of reworking should be the 

criteria for separating the reworked from the parent 

material? Our practice was to map the reworked material as a separate formation only where it forms a 

deposit more than 18 inches deep that has texture, composition, or bedding distinctive from that of the original deposit. In the absence of good outcrops the distinctions commonly must be made on the basis of rather 

subjective interpretations with the result that the map 

fails to show some embankment deposits that were 

transported only short distances. Another result, an 

inevitable one, is lack of complete consistency.

In order to show the relation of one deposit to another, two kinds of formation boundaries are distinguished on the map. Contact lines having hachures 

on one side indicate contacts of overlap; the hachures 

are drawn on the side of the younger and overlapping beds. Contact lines without hachures represent 

changes in facies, a condition that cannot properly be 

represented by a line on a map. In much of the area, 

however, not only the position but the nature of the 

contact has to be based on interpretation rather than 

on direct observation.

Landforms were not mapped. Wave-cut terraces 

for example were ignored, except as these provided the 

site for the accumulation of a distinctive and mappable 

deposit of sediment.

The first step in mapping a given part of the area 

was to observe the variations in ground texture. On 

flat areas such as the surfaces of the deltas and on the 

broad low fans or lake bottom sediments the soils were 

distinguished by whether they were composed largely 

of gravel, sand, silt, or clay. After mapping the 

ground texture in a few square miles, the boundaries 

between the different types of ground were walked and 

the locations were plotted on the map. In general it 

was necessary to zigzag back and forth across the 

boundary, and the position of the boundary might be 

highly uncertain even after such a traverse. It was 

found, however, that by tracing the boundaries in this
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH

way across the flat areas, they generally led to gullies 

or other places where an outcrop of the contact could 

be examined. At the outcrops the age relations and 

the overlap or lateral gradation of the one bed into the 

other could be established. It was not possible to 

correlate one outcrop with another except by laterally 

tracing the variation in the soil texture.

The origin of a deposit generally can be judged if 

its shape and its internal structure and composition 

are known. Much can be deduced from the internal 

structure and composition alone, but shape is probably the most reliable single criterion and, in an area 

like Utah Valley, this can be ascertained only by 

mapping.

Qualitative chemical analyses of the fine-grained 

sediments were made in the field to test the distribution of soluble salts in the several formations in order 

to provide a basis for selecting samples for quantitative analyses.

PREVIOUS STUDIES

The Bonneville Basin occupies a unique place in the 

science of geology. The classic description of it, including an analysis of lake processes, is that of G. K. 

Gilbert (1890). Gilbert's report on Lake Bonneville 

represents the only comprehensive study that has been 

made of the basin as a whole. References to the old 

lake, however, are made in the reports of the numerous 

other exploratory surveys in the region, and there 

have been many subsequent papers dealing with special 

or local problems. A selected bibliography at the end 

of this volume contains a list of references for the 

Bonneville Basin and related problems in other areas.

ECONOMIC GEOGRAPHY

Utah Valley has been primarily an agricultural 

area but the establishment of the Geneva Steel plant 

there has increased the likelihood that the valley will 

become industrialized and that it will develop a more 

balanced economy.

TOWNS

Provo, Utah's third largest city, had a population 

of almost 20,000 in 1940 and is considerably larger now. 

It is one of the major agricultural, industrial, and 

educational centers in the West, the service center for 

an extensive and rich agricultural area and for the 

Geneva and Ironton Steel plants, and the home of 

Brigham Young University. Other towns north of 

Provo are principally agricultural centers. All have 

grown considerably in the last few years; their populations in 1940 were as follows: Alpine, 444; American 

Fork, 3,333; Lehi, 2,733; Orem, 2,914; and Pleasant 

Grove, 1,941.

AGRICULTURE

The valley lands are highly productive and annually 

yield rich crops of grains, fruits, and vegetables. The 

agricultural economy would seem to be healthy 

judging from the fact that the majority of the farmers 

own their own lands. Most of the productive land is 

irrigated, but some areas are dry-farmed.

INDUSTRY

Packing plants and canning factories are numerous. 

Each year they ship large quantities of farm produce 

to all parts of the United States. Considerable sand 

and gravel is produced for concrete aggregate, for 

foundations, and for road metal. (See fig. 14.) The 

Provo Brick and Tile Co. utilizes clay from along the 

Provo River; other brick clay is quarried from older 

shale formations in the west part of the valley at the 

foot of the Lake Mountains. Refractory brick, made 

from silica sand brought from other parts of the 

State, is manufactured north of Lehi.

Heavy industry became established in Utah County 

in 1924 when the Columbia Steel Co. started its plant 

at Ironton, 4 miles south of Provo. In 1946 the 

Geneva Steel plant, which was constructed during 

World War II, was converted to peacetime production. 

Electricity is generated at hydroelectric plants located 

at the mouths of canyons that drain the mountains and 

at a steam-generating plant in Provo.

TRANSPORTATION

The area is served by two railroads, the main line of 

the Denver and Rio Grande Western Railroad Co. 

and a branch line of the Union Pacific Railroad. The 

network of roads, mostly following section or quartersection lines, is extensive. Main roads are paved and 

the principal side roads are metalled. A single trunk 

highway, which represents the combined United States 

Highway Nos. 50, 89, and 91, crosses the area. At 

Provo this connects with U. S. 189. Provo Airport 

is serviced by the Frontier Airlines.

HISTORY OF SETTLEMENT AND DEVELOPMENT

Archeological studies in Utah Valley have not as 

yet disclosed any very extensive prehistoric settlement 

by the Utes, Paiutes, or their predecessors. The 

Indians encountered by early white visitors were lazy 

and shiftless as compared with tribes met elsewhere 

and their numbers were small. They lived by hunting 

and fishing and by gathering native fruits, berries, or 

roots, but apparently they did not till the ground. 

Some had homes built of earth and grass, others lived in 

wickiups. Flint chips, imperfect arrowheads, and other 

tools are abundant locally in the valley but none were 

found in the Lake Bonneville deposits.
6 LAKE BONNEVILLE

The first white men known to have entered Utah 

Valley were the Spanish priest-explorers Padre Escalante and Padre Dominguez. They entered the valley 

at its south end by way of Spanish Fork on September 

23, 1776, while exploring a route from Santa Fe, N. 

Mex., to Monterey, Calif. (Auerbach, 1943, pp. 

64-66.) These explorers turned southward from Utah 

Valley and did not visit Great Salt Lake, although the 

Utes spoke of it, saying that its salt waters are injurious 

and "he who wets any part of his body with this water 

immediately feels an itching in the wet part." 

(Bancroft, 1889, p. 15.)

In the early 1820's began the epoch of the fur 

hunters, and names like William H. Ashley and Jedediah 

Smith take their place in the chronicle of Utah Valley 

history. Ashley's Rocky Mountain Fur Company 

built a fort by Utah Lake, which was known for a 

while as Ashley Lake, but a year later Jedediah Smith 

applied the name "Utah Lake" (Bancroft, 1889, pp. 

20-22). Provo River and Provo City were named for 

Etienne Provost, one of the fur hunters whose name 

has given rise to many legends. (American Guide 

Series, 1942.)

The Mormon settlers in the valley of Great Salt 

Lake lost no time in exploring the possibilities for 

establishing settlements in adjacent or nearby areas, 

including Utah Valley. Utah Valley was thus explored 

as early as 1847 (American Guide Series, 1942; Shelley, 

1945; Bancroft, 1889; and Huff, 1947). In 1849, 

because of troubles with Indians, Col. John Scott and a 

company of 31 men moved into Utah Valley and 

engaged one of the thieving Indian bands encamped 

at the site of Pleasant Grove. Several Indians were 

killed or wounded in this engagement (American Guide 

Series, 1942, pp. 39-40). The incident is commemorated by the name Battle Creek, the original name of 

Pleasant Grove and the name still used for the.canyon 

east of town.

Provo, first named Fort Utah, was settled in 1849 and 

by the beginning of 1851 had several hundred 

inhabitants.

Pleasant Grove, originally called Battle Creek; 

Alpine, which at first was called Mountainville; 

American Fork, which was called Lake City; and Lehi 

were settled in 1850 (Huff, 1947, pp. 161, 190, 231, 

268). Orem was settled about 1886 (Am. Guide Ser., 

1942, p. 160). All the towns except Orem were located 

originally alongside or near streams that flow into the 

valley from the Wasatch Mountains, and the development of Orem followed the construction of a canal to 

irrigate lands on the Orem bench. The towns were 

settled as agricultural communities. In all of Utah 

Valley, 59 square miles of land were under cultivation 

by 1877 (Powell, 1879, p. 124). Because of the sparse

rainfall during the growing season, practically all this 

area was dependent upon water from streams and 

springs for irrigation. The history of the development 

of water supplies and their relation to the present 

economy of the valley is discussed further on pages 

60-91.

Utah Valley first became serviced by through railroads in 1873 when the Utah Railway built a connecting 

line southward from the transcontinental railroad at 

Salt Lake Valley. The Denver and Rio Grande 

Western Railroad was completed in 1883.

Almost from the beginning large-scale reclamation 

measures were undertaken to bring the maximum 

amour^t of arable land under irrigation. As early as 

1854 the Territorial Legislature authorized .construction of a 40-mile canal to carry water from Utah 

Lake onto lands in Salt Lake Valley. Pleasant 

Grove, American Fork, and Lehi began sharing the 

water of American Fork River in the early 1850's and 

constructed irrigation ditches necessary for supplying 

the towns (Shelley, 1945, pp. 31-35). These and other 

early attempts to make surface water available for 

irrigation purposes have culminated today in the Deer 

Creek and related projects by the Bureau of Reclamation.

PHYSICAL GEOGRAPHY 

LANDFOBMS

The Basin and Range province extends from the foot 

of the Wasatch Range westward to the foot of the 

Sierra Nevada. Utah Valley is at the foot of the 

Wasatch, at the easternmost edge of the province.

The Valley was a bay in the basin of Lake Bonneville 

(fig. 1). Below the high-water level of the old lake, at 

about 5,100 feet altitude, the landforms are mostly 

those built of lake deposits; above 5,100 feet the landforms are mostly those of fluviatile erosion or sedimentation. The contrast is striking even to the untrained 

observer. Both in detail and in general pattern the 

landforms of Utah Valley (fig. 2) conform with those 

so masterfully described by G. K. Gilbert (1890, pp. 

23-170) for the Bonneville Basin as a whole.

In the central part of the valley, covering one-fourth 

or one-fifth of the whole valley floor, is Utah Lake, a 

body of fresh water. This is a natural lake that is 

drained by the Jordan River, a tributary of Great 

Salt Lake which drains Utah Valley through a gorge 

commonly known as the "Narrows". Today Utah Lake 

is used as a reservoir to serve the needs of about 48,000 

acres of- irrigated lands in Jordan Valley which lies 

north of Utah Valley. Natural storage in the lake has 

been increased by a small dam across the Jordan River 

in the Narrows. The lake level may be lowered as 

much as 9 feet below the natural outlet of the lake by
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH

FIGURE 2.—Block diagram of northern Utah Valley. View north. (Drawn by D. Fishburn.)

means of pumps which are operated throughout each 

irrigation season (pp. 65-66).

Because the shores slope very gradually small fluctuations in lake level cause considerable shift in the 

position of the shore. The shores and bottom are more 

muddy than sandy. The position of the shore as shown 

on plate 1 is approximately the position of the 4,490-foot 

lake level.

Rising northward from the shore of the lake is a 

broad plain that extends about 3 miles to the. foot of a 

bluff that forms the south edge of the Highland bench 

(fig. 2). The plain rises about 30 feet per mile, and at 

the foot of the bluff its surface is 100 feet higher than

the lake. The plain is formed by the deposits of silt 

and clay that accumulated on the bottom of Lake 

Bonneville. At American Fork and at Lehi broad low 

alluvial fans rise above the surface of the plain; the 

fan at American Fork is 3 miles wide and 50-75 feet 

high, the one at Lehi is 2 miles wide and 30-40 feet high. 

Overlooking the plain and the fans are bluffs about 

100-150 feet high at the south edge of the Highland 

bench. The surface of the bench rises smoothly northeastward about 200 feet in 3 miles, to the foot of thesteep slopes at the base of the mountains. The bench 

is a delta deposit built in Lake Bonneville by two 

streams American Fork and Dry Creek, which drain
LAKE BONNEVILLE

from the Wasatch Range. The streams are now in 

valleys cut 50 feet deep across the old delta. Except 

for the four small valleys entrenched in the bench (pi. 1) 

and minor gullying along the bluffs in front, Highland 

bench faithfully preserves its original deltaic form. The 

trend and slope of the bluffs is controlled by the dipping 

foreset beds; the smooth surface of the bench is built 

of topset beds.

Along the east side of Utah Lake is a low plain 

similar in form and orgin to that at the north, except 

that it is only 2 miles wide; west of the Geneva Steel 

plant, it ends in a 15-foot bluff at the lake shore. The 

east and higher part of this plain is interrupted by 

several north-trending ridges a few hundred feet wide 

and from 5 to 10 feet high. These ridges are built of 

sand and represent old bars deposited on the lake bottom silt or clay. At many places the sand has been 

whipped into small dunes. The plain ends eastward 

at the foot of Orem bench.

Orem bench, like the Highland bench, is built of the 

delta deposits brought into Lake Bonneville by Provo 

River. The bluffs along the west edge are 125 feet 

high. The surface of the bench rises smoothly 125 

feet in 3 miles to the steep slopes at the foot of the 

mountains. This surface is cut by the valley of Provo 

River, which is 75 feet deep. The town of Provo is on 

a broad low alluvial fan on the plain south of the bench.

The west side of Utah Lake is quite unlike the other 

sides. Bluffs 10 to 15 feet high form the lake shore 

and from there the surface, formed chiefly on alluvial 

fans, rises 600 feet in a mile to the foot of the mountains. 

In general these alluvial fans preserve their fan form 

although they are older than Lake Bonneville. Here 

and there the surface is interrupted by wave-cut or 

wave-built terraces that parallel the contours.

Bordering the valley on the east is the lofty Wasatch 

Range that rises precipitously to altitudes considerably 

more than a mile above the valley floor. The three 

largest streams in the area, Provo River, American 

Fork River, and Dry Creek, drain from these mountains 

into the valley. All the mountain streams except Dry 

Creek flow in narrow V-shaped, rocky gorges typical 

of fluviatile erosion. Dry Creek, above the town of 

Alpine, is in a glaciated valley and its cross section 

is U-shaped.

Across the north edge of the valley are the Traverse 

Mountains, which consist of smoothly rounded hills, 

wholly unlike the Wasatch. Their summits are about 

2,000 feet higher than the valley. At the Jordan Narrows the Traverse Mountains are broken by the gorge 

through which the Jordan River flows from Utah Valley 

to Great Salt Lake.

West of Utah Lake are the Lake Mountains, higher 

and rougher than the Traverse, but not so high as the

Wasatch. North of the Lake Mountains is a low pass 

by which Utah Valley is connected with Cedar Valley, 

the next valley west.

The western part of Utah Valley is rather typical of 

the Basin and Range province. Water there is scarce 

and streams are lacking. The eastern part is not 

typical, in that it adjoins large mountains from which 

large perennial streams drain into the valley.

CLIMATE

The present climate of northern Utah Valley is 

temperate and semi-arid but the climate of the past has 

differed considerably from that of the present time. 

The climatic changes that have occurred have been a 

major factor in controlling the natural processes that 

have operated in the past and that are operating now 

in the valley. In this section of the report are given 

the data pertaining to the present climate; interpretations about the past climates are given in the section 

on the geologic history of the area (pp. 39-42).

The following tables summarize some of the data 

collected by the Weather Bureau in and adjacent to 

northern Utah Valley. Precipitation increases and 

temperatures decrease eastward across the valley. In 

the Wasatch Range temperatures are lower and precipitation greater than in the valley. As shown by 

table 1, the average annual precipitation ranges from 

about 11 inches in the western part to nearly 17 inches 

along the base of the Wasatch Range. Recorded 

extremes since 1891 have been 5.94 inches in 1933 at 

Utah Lake near Lehi, and 29.22 inches in 1906 at 

Alpine. These geographic variations in the climate are 

illustrated, in part, in figure 3.

EXPLANATION 

-$- 11,90 in.

tteother stotion of U.S.Weother 

Bureou, showing overage 

annual precipitation

15 in.

Isohyetal line 

(overage annual precipitation)

Utah Lake 

pumping stotion 

ll.90in

LOWER AMERICAN F0"\

FIGURE 3.—Map showing variations in average annual precipitation in northern 

Utah Valley and adjoining mountains. Compiled from U. S. Weather Bureau 

data.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 9

TABLE 1.—Annual precipitation at weather stations in or near northern Utah Valley

[Data from U. S. Weather Bureau]

Year

1891— . — - — — - — — — -----

1892.. -----------------

1893———————————————

1894—————————— — —— ——

1895. ——————————— ————

1896. — ————— —— — ———

1897———— —— —— —— ——

1898. — ------------------

1899...--- — ------------

1900— . ————— — —— —— -

loni

1902

1903———— — ————— ——— IQfU

1905— _.-. ----------------

1906—————————— ————

1907——————————— ——

1908————————— — ————

1909—— —— ——— ——— —— ——

1910.. ------------------

1011

1912——————— ———— —————

1913—————— ————— —————

1914———— ——— ———— —————

1915.. — - — — ———— —————

1916—— ——— ———— — —— ———

1917—————————— ————

1918— — —————— ———— ——

1919-. — —— — ———— — — —

1920———————— ——————

1921. ——— —————— — ————

1922———— ———————————

1923. ———————————— ————

1924———————————— ————

1925.---. — — --------------

1926————————— — ———— 1Q9T

1928————— — —— ———— — ——

1929————— ————————

1930... ---------- --------------

1931 —— —— ——— — ———— ———

1932—— ———— ———— ——— — ——

1933— ——— —— ——— ————— ———

1934—— ——————— ———— —

1935— ——— — — ———— —————

1936—— ——— ————— — —— ———

1937———— ———————

1938——— —————————

1939-..——————— ———— —— .

1940 __ ————— — —— ————— ..

1941 _ . ————— —— ——— ——— ...

1942. ——— ————— ———— ————

1943.—————————— —————

1944..———————————— ——

1945———— ————— — ————— —

1946——————————————

1947———— —— ———————

1948—— ————— —————— ——

1949—— ——— ———— —— ——— —

1950. ———— —————————

Northern Utah Lake Valley

Mosida, 

altitude 

4,520

11.65 

10.72 

10.91 

11.14 

11.54

7.37 

13.31 

10.65 

10.61 

9.38

Utah Lake 

Pumping 

Station, 

altitude 

4,497

11.99 

16.36

19.15

21.22 

19.33 

14.47 

16.58 

17.05 

12.18 

13.43 

8.56 

16.59 

15.99 

13.34 

10.74 

6.85 

12.88 

10.21 

14.01 

8.40 

11.35 

12.97 

7.31 

10.49 

5.94 

9.29 

7.20 

12.42 

11.33 

10.16 

8.13 

9.91 

15.21 

9.21 

9.46 

11.55 

12.53 

13.34 

11.55 

8.76 

10.82 

7.87

12.46

Provo, 

altitude 

4,650

10.81 

12.38 

10.88 

9.57 

10.02 

13.51 

15.36 

13.95 

15.77 

8.73 

11.21 

9.69 

12.31 

15.32 

16.66 

20.93 

21.75 

17.07 

20.00 

12.55 

17.12 

18.10 

19.17 

16.41 

16.98 

20.56 

14.39 

18.29 

14.08 

21.82 

21.56 

19.92 

14.55 

11.64 

17.57 

18.71 

18.16 

8.95 

14.33 

14.12 

8.64 

11.40 

6.94 

10.71 

9.77 

18.29 

13.60 

15.39 

9.81 

15.47 

21.60 

11.43 

12.61 

17.15 

18.15 

18.02 

12.44 

10.78 

13. 68 

11.89

14.74

Provo 

bench, 

altitude 

5,000

13.89 

19.10 

13.90 

22.53 

22.38 

20.71 

15.54 

12.21 

19.37 

18.95 

20.66 

9.76 

15.95 

17.53

Lower 

American 

Fork, 

altitude 

5,063

17.40 

18.46 

19.93 

13.40 

19.61 

11.47 

23.34 

20.32 

18.13 

12.88 

11.62 

20.82 

15.49 

21.47 

10.31 

14.20 

16.62

14.57 

7.53 

12.77 

12.00 

20.88 

17.70 

16.74 

13.51 

19.02 

27.76 

14.89 

18.14 

22.00 

20.31 

20.82 

19.47 

13.82 

19.62 

12.03

16.67

Alpine, 

altitude 

5,000

15.34 

16.00 

13.58

11.38

19.72 

22.26 

29.22 

26.52

11.46 

12.89 

18.49 

13.98 

16.30 

16.58 

17.56 

17.14 

18.45 

11.52 

19.42 

22.06 

16.21 

13.48 

13.28 

19.31 

14.82 

21.85 

9.88 

18.01 

18.35 

11.81 

16.59 

8.94 

11.10 

10.78 

18.89 

15.54 

13.06 

10.44 

17.13 

21.75 

10.91

17.25 

17.06

Provo Elver drainage basin

Deer Creek 

dam, 

altitude 

5,285

30.02 

17.04 

20.71 

22.05 

26.28 

22.31 

22.27 

18.66 

26.19 

22.33

22.61

Timpanogos 

Cave, 

altitude 

5,600

23.61

31.10 

29.89

20.08 

28.28 

18.60

Timpanogos 

Summit, 

altitude 

8,300

25.34 

36.40 

49.08 

30.52 

40.29 

40.25 

48.17 

41. 69 

35.33

Heber, 

altitude 

5,593

18.84 

17.19 

15.04 

16.94 

18.17 

19.43 

24.26 

13.66 

15.29 

10.09 

13.32 

16.74 

12.94 

22.90 

20.05 

17.43 

27.92 

10.62 

18.39 

18.88 

15.37 

16.95 

14.75 

22.03 

12.16 

19.73 

13.74 

22.63 

21.86 

18.61 

15.05 

10.24 

16.37 

19.22 

20.24 

10.03 

14.72 

14.00 

10.24 

16.52 

11.43 

11.47 

9.23 

22.14 

18.27 

17.55 

19.61 

13.06 

18.17 

11.50 

16.00 

14.69 

20.37 

14.51 

17.51 

15.40 

18.11 

16.11

16.34

In an average year the frost-free season extends from 

mid-May to the end of September; it may be slightly 

longer on valley slopes, particularly on the southwestfacing slopes and terraces. During this 4%-month 

growing season the precipitation is generally less than 1 

inch per month in the valley; less than one-third of the 

annual precipitation falls during the growing season 

(table 2). By contrast, the rate of evaporation has 

ranged from 5.5 to 13.3 niches per month, and the 

total evaporation throughout the growing season 

generally exceeds 40 inches. (See table 3.) Thus the 

summer climate is sufficiently hot and dry that the 

amount of evaporation from lakes and reservoirs, as

well as from irrigated soils, far exceeds the quantity of 

water that falls as rain.

The dormant or nongrowing season (October to May) 

is the period of accumulation of water. These are the 

months of greatest precipitation and least evaporation. 

In the valley this is the time for infiltration of water 

from rain or melting snow, and by early spring the 

soil-water supplies doubtless reach their maximum for 

the year. In the mountains of the tributary drainage 

basin, the winter is a period of accumulation of snow, 

and as that melts, the reservoirs of the region receive 

their major increments of storage. The agricultural 

economy of the valley is founded upon utilizing these
10 LAKE BONNEVILLE

winter surpluses to overcome the water deficiencies of 

the growing season.

The annual evaporation from free water surfaces in 

the valley is generally more than three times as great 

as the annual precipitation, according to records from 

a standard Weather Bureau land pan (table 3). This 

pan cannot be operated in the coldest months, and for 

the months of operation the evaporation has varied 

from 50.9 inches in 1929 to 73.9 inches in 1934. In 28 

years the average recorded evaporation has exceeded 

60 inches a year. The considerable excess of evaporation over precipitation is a condition obviously different from that when Lake Bonneville was formed. 

Figure 17 shows the recorded fluctuations in the level 

of Utah Lake as compared to fluctuations in annual 

rainfall.

Continuous records of precipitation have been obtained for more than half a century at two towns in the 

drainage basin tributary to north Utah Valley. The 

rain gage at Provo has been located at a variety of 

positions during the half century—near the base of the 

Wasatch Range, in the center of town, and most recently at the airport near the west edge of the town. 

As a result the records for Provo do not correlate well 

with records of other stations in Utah Valley and 

adjacent areas. The gage at Heber, on the other 

hand, has remained at substantially the same location 

for 55 years, and an excellent record has been kept 

by John Crook and his descendants through three 

generations.

Statistical analysis of the Heber precipitation record 

for the 53-year period 1893-1945 shows a slight decrease in precipitation, from a general average of 17.6 

inches in the 1890's to 16.0 inches in the early 1940's. 

The average annual precipitation for the 53-year period 

is 16.53 inches.

The cumulative departure from average precipitation is of significant value in comparing precipitation

TABLE 2.—Average monthly and annual precipitation at weather 

stations in or near northern Utah Valley

[Data from IT. S. Weather Bureau]

Month

April———--- ——

July.... _—— ... ———

Utah Lake 

Pumping 

Station, altitude 4,497

1.16

1.08 

1.32

1.25 

1.26

1.07 

1.20

1.17 

1.14

1.14 

.65

.67 

.82

.84 

.98

.98 

.88

.76 

1.09

1.03 

.82

.82 

1.14

1.11

12.46

11.90

Provo, 

altitude 

4,650

1.54

1.50 

1.62

1.57 

1.59

1.51 

1.43

1.40 

1.49

1.36 

.73

.77 

.63

.68 

.82

.81 

.92

.82 

1.36

1.34 

1.18

1.17 

1.43

1.41

14.74

14.29

Lower American Fork, 

altitude 5,063

1.73

1.72 

1.69

1.69 

1.64

1.63 

1.90

1.91 

1.65

1.64 

.93

.94 

.90

.89 

1.01

1.01 

1.03

1.01 

1.44

1.44 

1.22

1.23 

1.53

1.53

16.67

17.25

Deer 

Creek 

Dam

2.45

2.41 

2.74

3.46 

2.02

1.96 

1.77

1.90 

1.05

.83 

1.55

1.97 

.52

.57 

1.17

1.07 

.85

.77 

2.48

1.81 

2.14

1.86 

3.34

3.07

22.61

23.22

Heber, 

altitude 

5,593

1.96

1.89 

1.99

2.05 

1.86

1.71 

1.40

1.38 

1.27

1.18 

.70

.87 

.83

.86 

1.00

.98 

1.02

.93 

1.34

. 1.31 

1.53

1.79 

1.64

1.38

16.34

16.17

TABLE 3.—Average evaporation (in inches') from Utah Lake near Lehi, Utah County, altitude 4,49? feet

[Data from U. S. Weather Bureau]

Year

1923. ——— — - — ——— — —— —

1924... ———— . — . ———— ———— _

1925- — — — — ———— — —— —

1926.. ..--_- — — — ——— — —— .

1927— — ——— ——— — ———— ———

1928—— — —— ———— — — — —

1929— —— — ————————

1930— — — —— — ———— ———

1931— — ———— ———— —— ———

1932— —— ——————— ——— —

1933-. --------------------------

1934-.--. ---------------------

1935.---. ----------------------

1936 — — — ———— —— — — —

1937

1938-. — — — — ——— ——— —

1939

1940--.- ----------------- ---------

1941 . _ -

1942— - ——— ———— —— — -------

1943.-. ------- ---------------

1944---- — -------------------

1945.-.--- — -----------------

1946-.----- — ---------------

1947

1948----..---- — --------------

1949. — --------------------

1950

January February March

2.8

3.8

3.6

3.1

2.7

3 7

3 T

2.5

3.8

3.4

3.0

3.1

3.6

3.6

3.1

2.1

2.3

3.7

3.5

2.9

3.2

3.2

April

6.4

6.0

6.0

5.6

5.0

4.2

6.0

6.7

5.6

ft f\

6.2

5.6

6.0

7.2

5.6

4.4

6.3

4.1

4.8

6.4

5.4

6.2

6.9

7.0

5.9

May

9.3

9.5

8.2

8.6

8.0

8.4

8.7

7.1

ft Q

9.1

6.8

11.7

7.5

10.9

10.6

7.3

9.4

10.2

8.8

7.4

9.1

8.2

7.6

8.2

8.1

10.2

7.8

7.9

8.7

June

9.7

12.5

7.8

10.7

10.0

9.6

9.8

10.9

11.6

8.6

11.9

10.3

12.0

10.0

10.3

9.7

9.9

11.8

9.2

10.5

10.2

8.1

8.1

12.9

8.1

9.5

9 2

11.4

10.2

July

11.2

11.5

9.8

9.8

9.7

10.9

10.2

11.0

13.1

10.6

10.9

13.0'

13.3

9.8

9.4

9.8

12.1

12.4

9.5

10.9

10.8

11.5

9.9

12.5

10.9

12.5

10.7

10.1

11.0

August

9.0

10.7

9.7

9.8

8.8

10.3

7.8

7.3

9.2

10.8

9.8

11.0

10.6

9.4

10.2

10.2

9.5

10.9

9.3

10.3

10.0

10.7

8.8

9.7

8.5

11.0

9.4

10.4

9.8

September

5.6

7.1

6.8

7.8

6.4

6.9

5.5

6.0

8.5

6.9

8.7

8.3

7.8

7.5

7.4

6.8

6.1

5.7

7.1

7.5

7.3

7.5

6.9

7.8

7.5

8.4

6.9

6.4

7.1

October

3.0

3.8

3.4

4.5

4.0

4.1

3.7

3.1

4.0

4.1

5.5

5.0

5.4

4.0

4.0

3.6

3.7

4.5

3.1

4.3

4.2

4.1

4.0

2.9

4.2

4.0

3.2

5.5

4.0

November

1.4.7'

.8

1.5

1.5

1.1

1.0

1.1

1.6

1.3

1.2

1.9

1.9

1.5

1.8

1.3

1.4

1.3

1.3

.9

1.5

1.3

1.1

December

0.2

.5

3.5

Season

49.2

65.0

56.2

62.5

57.2

59.0

50.9

56.2

65.2

59.7

62.8

73.9

66.0

61.2

62.4

56.5

59.8

64.8

57.0

61.5

63.2

57.8

53.8

65.2

57.2

61.8

58.5

66.7

60.4
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 11

with reservoir storage, whether on the surface or underground. If the reservoir storage is directly correlative 

with regional precipitation, it will increase during a 

series of years where precipitation is greater than 

average and will decline during drought years. A graph 

of cumulative deviation also shows a rising trend during 

wet cycles, a horizontal trend in a series of normal 

years, and a declining trend in drought cycles. Such 

a graph, based on the precipitation at Heber, shows a 

close correlation with the fluctuations of stage in 

Utah Lake (fig. 17).

GENERAL GEOLOGY

By CHARLES B. HUNT 

STRATIGRAPHY

Most of the northern Utah Valley floor is composed 

of sedimentary deposits that were laid down in the 

Pleistocene Lake Bonneville. Interbedded with these 

lake deposits is outwash from glacial moraines in the 

Wasatch Range and overlying the lake beds are recent 

fluviatile deposits. Beneath the Lake Bonneville group 

are several hundred feet of unconsolidated fanglomerate 

and interbedded lake deposits; which rest on late 

Tertiary water-laid volcanic tuffs, muds, and agglomerates.

In the mountains adjoining the valley, especially 

along the north side in the Traverse Mountains, is a 

series of porphyritic lavas, perhaps of mid-Tertiary age. 

At the northeast corner of the valley is a granitic 

mountain formed by the Little Cottonwood stock 

probably during the Tertiary. Pre-Cambrian, Paleozoic, 

and Mesozoic sedimentary rocks occupy most of the 

drainage basins of streams flowing to the valley from 

the Wasatch Range. Some of the valleys contain 

glacial deposits, but only Alpine Canyon was glaciated 

all the way to the mountain front. The Pennsylvania!! 

and Permian(?) Oquirrh formation comprises most of 

the Traverse Mountains and most of the mountains 

west of the valley.

The rocks in the mountains were the source from 

which the sediments in the valley were derived.

SOURCE ROCKS IN ADJOINING MOUNTAINS

PRE-CAMBRIAN, PALEOZOIC, AND MESOZOIC ROCKS

Pre-Cambrian, Paleozoic, and Mesozoic rocks in the 

Wasatch Range east of Utah Valley have been described 

by Baker (1947). An accompanying section summarizes his description of these source rocks.

Probably the total amount of valley sediments derived from each of these formations is roughly proportional to the thickness of the formation, except for the 

pre-Cambrian which is restricted to small areas at the 

foot of the mountains east of Provo and in the headwaters of American Fork River.

Generalized section of Paleozoic and Mesozoic rocks in theWasatch 

Range adjoining Utah Valley

[Generalized from Baker, 1947]

3

5 «

o

V

<g

1

po

03

5

0

1&

1a.

a

03

at* 

£

*?*

^ >£

&T3-i •£ o >>g Q 03 &> ^ro

'.S§gS 

SaP-"

•II

a B

fcH ft ^•53

d

03

gt*

01

Q

%03

£5

S 

03

g g

•C i'E

i&i

0 0

1

a

D

0

ft

Diamond Creek sandstone. ..

Kirkman limestone . . __

Madison, Deseret, Humbug, 

and Great Blue limestones.

Lynch dolomite.. --._.._

Tillite— — — — — —— — -

Phyllite-.- — — — — — —

ite and limestone boulders.

lenticular beds of sandstone and eonglomerate; 1,200 feet thick.

Shale, mudstone, and sandstone; glauconitic(?); 500 feet thick.

1,250 feet thick.

by shale; 1,100 feet thick.

thick.

Upper part of Ankareh formation as 

used by some authors; 675 feet thick.

Mostly red platy sandstone, considerable red shale, some limestone; 2,300 

feet thick. Some authors combine 

the upper 800 feet with the Chinle 

and refer to it as Ankareh; 1,300 feet 

of beds below this commonly is 

referred to Thaynes; basal 150-200 

feet referred to Woodside.

Mostly limestone, some black shale and

thin beds of phosphate, some sandstone; 2,000 feet thick.

Mostly coarse-grained sandstone; 850 

feet thick.

Limestone; 1,600 feet thick.

Mostly quartzitic sandstone, lower few

thousand feet contains considerable 

limestone; total thickness about 

18,000 feet.

Mostly black to dark-brown shale;

some interbedded limestone and conglomeratic sandstone; 1,600 feet 

thick.

Practically all limestone; 4,600 feet 

thick.

Dolomite, some limestone; 250 feet

thick.

150 feet thick.

600 feet thick.

Phyllitic, olive-green shale; some lime

stone and quartzite; 250 feet thick.

Hard quartzite; some conglomerate at

base; 1,200 feet thick.

Well-rounded boulders of dolomite

and quartzite as much as 1 foot in 

diameter, in firm coarse-grained matrix that has slatey cleavage; 150 feet 

thick.

A few hundred feet exposed, principally at base of mountain east of 

Provo; some in headwaters of American Pork River.
12 LAKE BONNEVILLE

The Pennsylvanian formations comprise most of the 

Traverse Mountains along the north side of the valley 

and the Lake Mountains west of the valley.

TEBTIABYC?) BOCKS 

LITTLE COTTONWOOD STOCK

Little Cottonwood stock, a quartz monzonite intrusive into Paleozoic rocks (Calkins and Butler, 1943, pp. 

38-40), occupies somewhat more than half the drainage 

basin of Dry Creek and extends into the headwaters 

of American Fork River. In describing gravel and 

other sediments of Utah Valley derived from this 

source, the materials will be referred to as granitic.

LAVAS AND WATER-LAID VOLCANICS

Rather glassy and distinctly porphyritic lavas crop 

out in the Traverse Mountains and gravels derived 

from these lavas are abundant in the younger valley 

deposits in the north part of the valley. Within northern Utah Valley there is a single outcrop of the old 

lavas, in the W/2 sec. 2, T. 5 S., R. 1 W. Similar lavas 

and some basalts crop out extensively along the Provo 

River east of the Wasatch Range, but the gravels from 

these eruptives comprise only 2 or 3 percent of the 

sediment brought into Utah Valley by Provo River.

On the east slope of the Wasatch are some waterlaid volcanics, mostly reworked tuffs. Their present 

areal extent is not great but their presence would suggest that the mountains were once extensively covered 

with these easily eroded materials, and if so, they 

probably contributed to sedimentation in the valley far 

more than their thickness or present areal extent would 

suggest.

These lavas and water-laid volcanic deposits almost 

certainly are of Tertiary age, and they may represent 

intermittent eruptions spanning a considerable part of 

Tertiary time.

QUATEBNABY DEPOSITS IN THE MOUNTAINS 

GLACIAL DEPOSITS

Extensive moraines and other glacial deposits have 

accumulated in the drainage basins of Provo River, 

American Fork River, and Dry Creek. Along Dry 

Creek, glaciers descended at least twice to the very 

edge of Utah Valley. A conspicuous moraine containing fresh, unweathered granitic debris extends from 

high on the mountain to the mouth of Alpine Canyon. 

A less conspicuous and older moraine that has been 

deeply weathered extends half a mile farther into the 

valley.

ALLUVIAL AND OTHER STJRFICIAL DEPOSITS

Some of the valleys in the mountains contain fairly 

deep alluvial fill. Provo River at Heber, immediately 

east of the Wasatch Range, is in a wide valley containing extensive and deep fill, but the deposit is not well 

enough known as yet to appraise its effect on 

sedimentation in Utah Valley.

In many of the more rugged sections of the mountains, 

broken rock has accumulated in large talus cones at 

the foot of cliffs or steep rocky slopes. At other 

places that are only slightly less steep and rocky, 

hillside wash is mixed with the broken rock in steep 

colluvial cones. At still other places there is preserved an old topographic surface that consists of 

comparatively rounded landforms and presents a 

decidedly more mature aspect than do the taluslittered rocky cliffs so conspicuous along the main 

canyons and in the glaciated areas. Mantling this old 

surface are remnants of an old and deep soil. (See 

p. 44.) The old surface and the soil on it are being 

dissected today, and it is evident that both were 

formerly much more extensive. Indeed, the whole 

range probably once had a mature surface and deep 

soil like those of the remnants. If so, erosion of the 

old deep soil could account for the excessive proportion of fine-grained sediments that are found in 

some of the deposits of Utah Valley, notably in the 

Alpine formation.

The Traverse Mountains, whose valleys have only 

small drainage basins, is composed almost entirely of 

smoothly rounded hills that are mantled by a deep 

and old soil. The Lake Mountains appear to be more 

like the Wasatch in that they have small remnants of 

the old surface and soil preserved in the midst of the 

rocky and youthful landforms that are being developed 

by the present erosion cycle.

SOME RELATIONSHIPS BETWEEN THE SOURCE ROCKS 

AND VAJULEY SEDIMENTS

The areal distribution of the source rocks has been a 

major factor controlling variations in composition 

of the sediments in different parts of the valley.

The sediments being brought into the valley by 

Provo River contain more quartzite than limestone, 

because of the wide extent of the tremendously thick 

Pennsylvanian series along the river where it crosses 

the Wasatch Range. Mixed with these sediments 

is a small percentage of lavas derived from the volcanics above Heber. The sediments being brought 

into the valley by American Fork River contain about 

an equal proportion of limestone and quartzite because 

the pre-Pennsylvanian formations there are more 

extensive than along Provo River. In addition, 

sediments of the American Fork River contain a small 

percentage of granitic material, for the headwaters 

of the river drain the southeast side of the Little 

Cottonwood stock. Dry Creek roughly follows the 

contact between the granite of the Little Cottonwood 

stock and the pre-Pennsylvanian limestone and quartz-
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 13

ite on the south side of the stock; sediments being 

brought into the valley by Dry Creek are 30 or 40 

percent granitic and the remainder is quartzite or 

limestone.

The conditions of drainage, however, varied a good 

deal during Late Tertiary and Quaternary time. 

During late Teritary time most or all of the tributary 

mountain area must have been covered with volcanic 

ash. At several stages during the Pleistocene history 

of the mountains extensive glacial deposits were 

formed; at other stages fluviatile erosion was as dominant as it is now, and at still other stages the rate of 

weathering so exceeded the rate of erosion that deep 

soil formed over the source rocks. There were times 

in the past, therefore, when the source rocks on the 

mountains were quite different than they are today 

and these differences are recorded in the types of sediment that have been deposited in the valley at different 

times.

DEPOSITS IN UTAH VAULJEY

SALT LAKE FORMATION (TERTIARY)

The oldest rocks recognized thus far in the valley 

are a well-stratified series of water-laid volcanic 

deposits. Similar rocks are widespread in northwestern 

Utah and have been referred to as the Salt Lake formation. (Wilmarth, 1938, p. 1897.) They are thought 

to be of late Tertiary (Pliocene ?) age.

Although the Salt Lake formation is rather extensively exposed in several of the valleys of northwestern Utah and similar beds are found in the Wasatch 

Range east of Mount Timpanogos, these beds have 

not been systematically studied and mapped. In 

Utah Valley the formation is exposed only in a very 

small area in the Jordan Narrows, at the extreme 

northwest corner of the valley (pi. 1). Mapping other 

basins having more extensive outcrops of the formation 

no doubt will reveal its habit and will permit more 

satisfactory interpretation of its extent, thickness, 

and potential importance in Utah Valley than can be 

made now.

In the Jordan Narrows about 200 feet of beds belonging to the Salt Lake formation are exposed. The 

lower 100 feet of the exposed beds are white or very 

light gray. Near the base is a 3-foot bed of friable 

tuff, composed largely of glass shards but including 

a few tiny crystals of feldspar and quartz. The fresh 

rock contains little or no carbonate. Overlying this 

tuff is a series of alternating dark-gray silt and white 

or light-gray, firm, ledge-forming beds that probably 

are cemented, reworked tuffs. The individual beds 

range from 2 to 20 feet in thickness; included wth them 

are a few, very thin, clay partings. The firm ledgeforming beds contain poorly preserved molluscan remains that Dr. T. C. Yen of the U. S. National Museum 

identified as belonging to the snail genus Gfyraulus. 

These beds perhaps are reworked tuffs that have been 

cemented with lime. They effervesce strongly in acid 

and yield strong calcium precipitates. Under the 

microscope can be seen an occasional glass shard.

These light-colored beds are overlain unconformably 

by a series of buff beds with a basal conglomerate which 

dips 5° less than the underlying light-colored finetextured beds. The contact is channeled and some of 

the channels are 3 feet deep. About 15 feet of the overlying beds are cut off northward.

The beds above the unconformity are buff. The 

basal conglomerate is about 15 feet thick and contains 

lava and quartzite boulders as much as 3 feet in 

diameter. Above this is 50 feet of moderately consolidated buff sand and silt, which apparently is reworked crystal tuff partly cemented by lime carbonate.

These buff beds are cut off southward at a fault, 

on the south side of which is at least 50 feet of conglomerate that may also be part of the Salt Lake 

formation.

The deepest penetration into the Salt Lake formation 

by wells is believed to have been by a well drilled at 

Cutler in the center of sec. 5, T. 5 S., R. 1 E. The 

driller's log and geologic interpretation for this well are 

tabulated below.

Driller's log of Union Pacific RR well (D-5-1) 5caa-2 at Cutler.

Utah

Eight-inch well drilled 690 feet deep in December 1915. Located in the 

NEJ4NEJ4SWJ4 sec. 5, T. 5 S., R. 1 E.; altitude of land surface about 4,609 feet 

above sea level. Well plugged and abandoned prior to 1945. (W)=Water-bearing.

Geologic formation Material

Soil...---- — - — ----------

Sand, white (W)-— — — — —

Gravel (W).--— — — — — —

Thickness 

(feet)

3

5

8

1

17

9

10

19

10

6

8

10

34

22

10

8

2

23

11

2

13

2

4

6

7

24

9

17

150

Depth 

(feet)

3

8

16

17

26

36

46

52

60

70

92

102

110

112

135

146

148

161

163

167

173

180

194

203

220
14 LAKE BONNEVILLE

Driller's log of Union Pacific RR well (D-5-1) 5caa-2 at Cutler, 

Utah—Continued

Geologic formation Material

Gravel, coarse, and sand ( W) ...

Sand(W)— — — - — — — _--

Clay, yellow and white, hard...

Thickness 

(feet)

4

2

4

3

3

13

17

3

10

5

3

33

10

11

3

2

6

14

14

44

8

13

7

3

35

3

18

26

44

- 6

27

25

3

470

Depth 

(feet)

224

226

230

233

240

243

256

273

276

286

291 

306

309

342

352

363

366

376

378

384

387

401

415

421

465 

473

486

493

496

531

536

554

580

624

629

635

662

687

690

No cuttings from this well were available. Judging 

from the driller's log the top of the formation is about 

220 feet deep (pi. 4, sec. F-F'}.

This well and others farther south, together with the 

outcrop of the formation in Jordan Narrows, indicate 

that the surface of the Salt Lake formation slopes 

southeastward under the valley. In the Narrows 

the top of the formation is at an altitude of about 

4,600 feet; at the Cutler well its altitude is about 

4,400 feet; at the well in sec. 10, T. 5 S., R. 1 E., its 

altitude is no higher than 4,275 feet; at the well in sec. 

26, T. 5 S., R. 1 W., its altitude is below 4,160 feet; 

and at Geneva the altitude of the uppermost Tertiary 

beds is considered to be about 3,750 feet.

To the extent that the Salt Lake formation resembles the late Tertiary water-laid volcanic beds in 

other parts of the Basin and Range province, the 

formation could be expected to embrace several units 

separated by angular unconformities and to span a 

considerable period of time.

The lava and quartzite boulders in the conglomerate 

at Jordan Narrows are like the lava and quartzite in the 

adjoining hills of the Traverse Mountains and evidently 

were derived from them. This is evidence that Utah 

Valley had already started to develop as a structural 

depression when the Salt Lake formation was deposited.

By analogy with the similar valleys along the lower 

part of the Colorado River, where the late Tertiary 

history is better revealed than in Utah Valley, it is 

inferred that Utah Valley was a well-developed structural basin and site of sedimentation in late Tertiary 

time. If so, the Salt Lake formation must include 

beds of ash that fell hi the basin, as well as other beds 

reworked from the ash that must have fallen on the 

adjoining and rising mountains.

Volcanic detritus, characteristic of the Salt Lake 

formation exposed at Jordan Narrows, was not found 

in the cuttings from the deep well of the Geneva Steel 

Co. (See fig. 5.) However, in other localities (Thomas 

1946, pp. 116-118; Williams, 1948, pp. 1121-1164). 

Tertiary strata of nonvolcanic debris overlying tuffs 

and breccias have been included within the Salt Lake 

formation. The sediments penetrated in the lower 

340 feet of the Geneva deep well are regarded as 

Tertiary. Data obtained from the well cuttings, 

however, are inadequate to identify the materials as 

part of the Salt Lake formation as described in various

areas.

PRE-LAKE BONNEVILLE DEPOSITS (PLEISTOCENE)

Pleistocene pre-Lake Bonneville deposits under Utah 

Valley are several hundred feet thick. The deposits 

have been penetrated by several wells; one drilled 

by the Geneva Steel Co. is more than 800 feet deep. 

The only exposures of the pre-Lake Bonneville deposits 

are the huge alluvial fans that form a fringe around the 

valley and that spread apronwise from the foot of the 

adjoining mountains.

Exposed deposits.—Gilbert recognized the fans as 

older than Lake Bonneville (Gilbert, 1890, pp. 220- 

222) because the lake has impressed its shore mark 

on those fans that rise above the high-water mark of 

the lake. In addition to this evidence, at many places 

in Utah Valley the Lake Bonneville group is exposed 

where it overlaps onto the fan deposits.

All the fans are alike in being composed of poorly 

sorted materials, angular boulders, cobbles, and gravel 

in a sand and silt matrix; but the fans differ from one 

another in the kinds of gravel they contain, depending 

on the source rocks in the immediately adjoining mountains. The fan materials are in large part poorly consolidated but in this report they are referred to as 

fanglomerate.

The pre-Lake Bonneville fans along the west side 

of the valley and those along the south side of the 

Traverse Mountains were derived largely from the 

quartzitic part of the Oquirrh formation and are composed mostly of quartzitic material. The fans along 

the south side of the Traverse Mountains also include 

some material derived from the porphyritic and glassy
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 15

lavas in the range. Pre-Lake Bonneville fans east of 

Alpine and east of Provo contain limestone and 

quartzitic material in about equal proportions. The 

fans east of Alpine were derived from the older Paleozoic 

limestones and Cambrian quartzite. All the Paleozoic 

•formations, including the Oquirrh, contributed material 

to the fans east of Provo. The fans between American 

Fork Canyon and Provo River, on the other hand, 

were derived very largely from Paleozoic limestone 

formations.

The fans along the foot of the Wasatch Range and 

along the west side of the valley contain abundant 

cobbles and boulders, many a foot or more in diameter; 

whereas the fans at the south side of the Traverse 

Mountains contain fine gravels, probably because the 

Traverse Mountains are lower than the Wasatch and 

have not been deeply dissected.

The sand mixed with the gravelly or bouldery 

materials in the fans consists of subangular grains, in 

contrast to the lacustrine sands which are rounded or 

subrounded (fig. 4).

o oo

GOO <><;

IA IB

Material from sond bars

2A 2B 

Sond matrix from grovel member 

of Prova formation in 

Highland bench delta

Sond from silt bed overlying 

gravel on Highland bench

4 

Alluvial sand Sand matrix from 

deltoic grovel 

near fool of 

mountains

S MILLIMETERS.

FIGURE 4.—Sketches to illustrate some variations in sizing and rounding of sand 

grains in different kinds of deposits in Utah Valley.

The surface of the fans and the obscure bedding in 

them slope several hundred feet per mile toward the 

basin. Commonly the fan form is perfectly preserved, 

but at several places the fan deposits have been faulted 

and the upfaulted segments are being eroded. The 

deposits northwest of Alpine have been rather maturely 

dissected into rounded hills resembling those formed 

on the bedrock in the Traverse Mountains. Mantling 

these hills of fanglomerate is deep soil (p. 44). Some 

of the fans along the foot of the Wasatch Range and 

also locally along the foot of the Lake Mountains have 

been faulted; the upfaulted segments are being dissected. These also are mantled by deep soil and at

several places the old soil is overlapped by the Lake 

Bonne ville deposits. The fans therefore were deeply 

weathered and covered by a deep soil prior to or during 

the early stages of Lake Bonneville. (See fig. 10.)

Most of the fans are covered with a recent mantle of 

boulders and finer sediment, but these Recent deposits, 

which have been washed from the mountains since the 

time of Lake Bonneville, constitute only a thin layer on 

the main body of the fans. Gilbert recognized this fact 

though he did not stress it in his report. An entry in 

his notes dated August 12, 1872, states, "The gravel 

slopes made since the lake are a small item compared 

with those made before." Because of the comparative 

insignificance of the post-lake deposits they are incompletely shown on the geological map (pi. 1).

At some places, notably at the west end of the Traverse Mountains, the pre-Lake Bonneville fluvial deposits were reworked slightly by the waves and currents 

of Lake Bonneville. The reworking is revealed by 

small wave-cut terraces or by small embankment bars. 

Properly, such reworked material should have been 

mapped as part of the lake formations but this was not 

feasible except where the reworking was sufficient to 

produce a deposit that differs in texture, composition, 

or sorting from the original fluvial deposit.

These pre-Lake Bonneville fluvial deposits are exposed today only near their source, the foot of the 

mountains. Basinward they are concealed by younger 

sediments but numerous wells in the interior of the 

valley furnish considerable information about the 

buried deposits and suggest that parts of them are of 

lacustrine rather than fluviatile origin.

Concealed deposits.—Wells drilled in the valley show 

that the top of the pre-Lake Bonneville deposits is 

commonly from 75 to 100 feet below the surface. At 

the Geneva Steel plant, where the best record was obtained (A-16225), the top of the pre-Lake Bonneville 

deposits is 105 feet below the surface and is marked by 

a peat layer that clearly records the subaerial conditions prevailing before Lake Bonneville came into 

existence.

Figure 5 shows the log of this well. The well penetrated several thick deposits of clay that apparently 

represent glacial lakes; their thickness is less than the 

clay deposits of the Lake Bonneville group so it could 

be inferred that the more ancient lakes were shorterlived. The gravel deposits separating these presumed 

glacial-lake clay deposits are probably largely of fluvial 

origin and probably represent interglacial stages. It 

should be noted, however, that in this well there are no 

means for distinguishing fluvial from deltaic gravel 

deposits, and some of the gravel, especially between 

about 240 and 420 feet, very possibly was deposited 

as deltas in glacial lakes.
16 LAKE BONNEVILLE

DRILLERS' LOGS

(D-6-2) 

8 bcd-IO 

0-1747

PROPORTIONS OF GRAVEL, 

SAND, AND CLAY 

OBSERVED IN SAMPLES 

(D-6-2 8 bcd-4

ELECTRIC LOG

(D-6-2) 8 bcd-4

A-16225

100

200

300

40D

500

6DO

700

800

Lake Bonnevilte Group

(

Peat 

Probably fluvial gravVsl 

(inter glacial ?)

Probably mostly glacial lake 

deposits', the gravel may be 

lacustrine or fluvial interglaciol

Probably mostly fluvial intergloclal 

deposits

Probably glacial lake deposits

— — Rant material

Plant material

-- Plant material

FIGURE 5.—Logs of wells drilled at Geneva Steel plant.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 17

These gravel beds constitute important aquifers 

which yield water, under artesian pressure in the lower 

parts of Utah Valley. Most wells obtain water from 

the uppermost pre-Lake Bonneville gravel, the overlying Lake Bonneville group forming the confining 

layer, but many wells penetrate the second thick bed 

of clay and obtain water with higher pressure head 

from deeper gravels. In many places the pre-Lake 

Bonneville gravels are highly permeable, and Utah 

Valley consequently has some of the most productive 

flowing wells in the State. The geology of these 

deposits, particularly as it affects ground-water hydrology, is discussed further on pages 60-91. Geologic 

sections based on well logs (pi. 4) show the principal 

aquifers topped by wells in north Utah Valley.

LAKE BONNEVILLE GROUP

Lake Bonneville, the last of the great Pleistocene 

lakes that flooded Utah Valley, covered almost 20,000 

square miles in western Utah and had a maximum 

depth of about 1,000 feet (fig. 1). Utah Valley was a 

bay along the eastern side of the lake.

The deposits that were laid down in Lake Bonneville 

in northern Utah Valley can be divided into three 

formations, each of which represents a different stage 

in the history of the old lake. These are the Alpine, 

Bonneville, and Provo formations, and they correspond 

respectively to what Gilbert (1890, pp. 90-152) referred 

to as the Intermediate, Bonneville, and Provo stages 

of the lake. Around Great Salt Lake, Gilbert recognized a fourth stage that he named the Stansbury. 

This is the youngest stage and represents a lake level 

lower than the other three and approximately at the 

level of Utah Lake. The sediment in the bottom of 

Utah Lake therefore includes material deposited during 

the Stansbury stage and more recent time.

Since Lake Bonneville time there has been little 

erosion within the valley, and the younger of the lake 

deposits still preserve the constructional forms they 

had when they were deposited. Moreover, since Lake 

Bonneville time the climate has become drier; the soilforming processes are feeble and soil profiles on the Lake 

Bonneville group are only weakly developed except 

very locally where there is or has been an excess of 

surface water.

ALPINE FORMATION

Oldest of the Lake Bonneville group is the Alpine 

formation. Gilbert used the name Intermediate to 

refer to the lake stage represented by these deposits, 

the name having been derived from the fact that 

around the sides of the valley these deposits are exposed 

at levels intermediate in altitude between the Provo 

and Bonneville levels (Gilbert, 1890, pp. 135-154). 

The name Intermediate, however, is unsatisfactory

because the deposits of that stage underlie the other 

Lake Bonneville formations. For this reason the 

name Alpine formation is introduced in this report 

instead of the old name. The formation is named for 

the town, around which there are numerous typical 

exposures.

Typically, the Alpine formation contains a high 

proportion of fine-textured sediment, mostly silt. 

(See fig. 13.) Sorting is excellent; the bedding is very 

distinct and in the finer-grained sediments individual 

beds commonly are only a fraction of an inch in thickness. The upper part of the formation is light gray but 

it is horizontally striped by thin beds that are rusty 

colored; the lower part of the formation is somber gray.

In the interior of the valley the formation thickens 

southward from about 50 feet in the vicinity of Lehi to 

about 100 feet near Provo. In the interior of the 

valley the formation is clayey although beds of gravel 

and sand are encountered in some wells.

Around the sides of the valley the Alpine overlaps 

onto the pre-Lake Bonneville alluvial fans, and these 

overlapping beds are nearly horizontal where they abut 

against the steeply sloping surface of the alluvial fans 

or other pre-Lake Bonneville deposits. The present 

erosion surface cuts off the basinward parts of the beds 

which, if projected, would extend well above the present 

valley surface. Probably the Alpine formation thinned 

rapidly basinward, but later erosion has destroyed the 

evidence for that thinning.

Although the Alpine formation is in large part 

fine-textured even near the steep front of the mountains, it does contain considerable sand and some 

gravel. As would be expected, these coarse clastic 

deposits are thickest near the mouths of the canyons 

draining the mountains. On the basis of prevailing 

texture the formation is divided into three members— 

one composed largely of gravel, one largely of sand, 

and one largely of silt and (or) clay. These members 

are given lithologic names but they are not homogeneous 

units; the silt member for example, contains thin layers 

of clay, sand, and even some gravel. Variations like 

this are seen in most outcrops.

Gravel member.—The gravel member of the Alpine 

formation is exposed at the mouth of American Fork 

Canyon, along Dry Creek at Alpine, and near the 

Jordan Narrows. In addition some wells in the valley 

encountered gravel in beds assigned to the Alpine 

formation.

At the mouth of American Fork Canyon the gravel 

member crops out in the steep slope along the west 

side of the highest-level lake benches on each side of 

the stream. The north side of the southern bench and 

the south side of the northern bench are entirely 

gravel. No means were found for distinguishing be-
18 LAKE BONNEVILLE

tween the gravel of the Alpine formation and the 

overlying gravel of the Bonneville formation. Presumably the lower hundred feet or so is Alpine.

Northward and southward from the stream, however, 

the gravel of the Alpine formation grades laterally 

into silt and sand, so the formation there becomes 

distinctive from the overlying Bonneville formation. 

Half a mile north of the stream the gravel is in two beds, 

each only a few feet thick and separated by many feet 

of fine-textured sediments; three-quarters of a mile 

south of the stream the gravel is in three thin beds. 

These are tongues of gravel that thin northward and 

southward and grade into finer sediments.

The gravel is typical of that transported by American 

Fork River in that it is composed very largely of 

limestone and quartzite in roughly equal proportions. 

The size of the gravels diminishes considerably within 

a short distance north and south from the stream; 

near the stream many cobbles are 6 inches in diameter, 

but half a mile away the common large ones are only 

about 2 inches in diameter. On the map (pi. 1) these 

gravel tongues are shown grading laterally into the 

silt member of the Alpine but, as might be expected, 

this part of the silt member contains considerable 

sand.

Half a mile west of the town of Alpine the gravel 

member is about 50 feet thick and includes volcanic 

and quartzitic material derived from the Traverse 

Mountains and granitic material from the Little Cottonwood stock. Limestone is not abundant. The 

gravel deposits north and northeast of town are similar 

except that they include considerable limestone. The 

gravel west of town thins westward and within about 

a mile its place is taken by sandy beds, evidently the 

result of lateral gradation. These gravels were brought 

into the old lake by Dry Creek and its tributaries.

At least 40 feet of the gravel member of the Alpine 

formation is exposed on the upstream side of the Jordan 

Narrows. This gravel is in beds a few inches to a 

few feet thick separated by a few to several feet of sand 

and silt, but even the silty beds contain some pebbles. 

The gravels are not coarse; most of the pebbles are 

one-half inch in diameter. The pebbles are very well 

rounded. Most are quartzite, though some are limestone, and probably were derived from the Traverse 

Mountains. With them is an occasional pebble of 

granite evidently brought from the vicinity of Dry 

Creek. Interbedded with the gravel is finely laminated 

sand or silt. The bedding in some of these fine-grained 

sediments is highly contorted but the contorted bedding 

ends upward and downward at plane bedding surfaces. 

It is likely that the gravel member at this locality represents an old spit built westward from the Traverse 

Mountains.

The gravel member probably is present beneath the 

sand member at the mouth of Frovo- Canyon. A mile 

and a half northwest of the canyon mouth is a bed of 

gravel that disappears northwestward, perhaps by gradation to sand. Toward the canyon mouth this bed 

is concealed but in that direction it probably is persistent and perhaps thicker.

Along the mountain front the gravel member of the 

Alpine formation is found only near the mouths of 

large canyons. Between the canyon mouths the Alpine 

is fine grained, locally even clayey. The low proportion of coarse material in the formation, even where it 

overlaps the steep slopes on the pre-Lake Bonneville 

alluvial fans, is in striking contrast to the habit of the 

Bonneville and Provo formations, both of which contain a large proportion of gravel.

There appears to be little gravel in the formation in 

the interior of the valley although some was encountered in a few wells. Several gravel beds, for example, 

can be recognized in the logs of the holes drilled to test 

foundation conditions at the Geneva Steel plant (fig. 6). 

These beds seem to be lenses elongated in a northwesterly direction. All of them are in the upper half 

of the formation; the lower half is sand, silt, or clay. 

Apparently the lenses end westward near the center 

line of section 8, for no gravel was encountered in the 

numerous holes farther west, nor is gravel seen in outcrops in the bluffs at the edge of Utah Lake. Nothing 

is known about their extent eastward.

Considerable sand and gravel also is reported in the logs 

of some wells that penetrated the Alpine formation in 

the vicinity of Lehi and a few miles south of the 

Geneva Steel plant, in sees. 28 and 34, T. 6 S., R. 2 E.

Sand member.—The sand member of the Alpine 

formation generally is found near the mouths of the 

canyons that drain into the valley. In addition, this 

member underlies the Provo formation at the Geneva 

Steel plant and at the bluffs facing Utah Lake west of 

the plant.

The sand member is finely laminated, and contains 

layers of grit, or even gravel, and layers of silt or clay. 

At outcrops there is considerable iron stain, mostly 

along the bedding planes. Sieve analyses by engineers 

who investigated foundation conditions for the Geneva 

Steel plant indicate that most of the sand in the Alpine 

formation at the plant is finer than I millimeter in 

diameter, 50 percent is finer than 0.3 millimeter, and 

10 percent is finer than 0.1 millimeter.

The sand member is about 150 feet thick a mile 

northwest of the mouth of Provo Canyon. However, 

near the middle of the member are several beds of silt 

and clay, shown on the map (pi. 1) as a single tongue of 

the silt and clay member. The sand above and below 

the silt and clay thins northwestward as the silt and
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 19

*«x

- 4*

*°

i\ 

>

i : 

<

X^O.

. x*a X

<ft"*N

4525

Approximate position of drill hole 

Each pattern represents a lense 

of gravel. The contours show 

the shape and position of 

the lense

1000

T6S.,R.2E.

2000 Feet 

__I

approximate position by dots.
20 LAKE BONNEVILLE

clay thicken, presumably because of lateral gradation 

in facies.

Silt and clay member.—The silt and clay member of 

the Alpine formation is exposed along the foot of the 

mountains between the canyon mouths, and it underlies much of the interior of the valley.

The member everywhere is thinly and evenly bedded. 

Individual beds range from % to 2 inches in thickness 

and are composed of clay, silt, sand, and grit in alternating layers, but the finer textures predominate. 

(See fig. 13.) Streaks of iron oxide along the bedding 

planes produce rusty-colored outcrops.

In places the laminations are fine enough to be suggestive of varves. As many as 40 clay layers separated 

by 40 layers of silt, sand, or grit have been observed in 

a section only 60 inches thick.

These finely laminated, fine-textured lake beds overlap steep surfaces on the bouldery, pre-Lake Bonneville 

alluvial fans. The contact has been examined at many 

places but it reveals surprisingly little reworking of the 

fan materials. This condition prevails even at places 

where the later stages of the lake left conspicuous signs 

of strong shore current.

Ostracodes, collected from the silt and clay member 

in an excavation for a bridge abutment where the road 

west from Lehi crosses the Jordan River, were submitted to Fred M. Swain who has reported the following 

species:

Candona sp. Abundant fragments.

Limnicythere sp. aff. L. sancti-patricii Brady and Roberfcson.

Rare. 

Limnicythere sp. aff. L. inopinata (Baird). Rare.

Swain states that these forms are probably Holarctic, 

and that Limnicythere inopinata suggests a possible 

saline environment, but that the evidence against an 

entirely fresh-water environment is not conclusive.

Inasmuch as Lake Bonneville had not developed an 

outlet at the time the Alpine formation was deposited, 

it probably contained at least moderate quantities of 

salts in solution. There is geochemical data in support 

of this. (See p. 34.)

Engineers studying foundation conditions at the 

Geneva Steel plant made some mechanical analyses of 

stiff silty clay from test holes in the Alpine formation. 

Seventy percent of the clay is finer than 0.02 millimeter, 

45 percent finer than 0.005 millimeter, and 10 percent 

finer than 0.001 millimeter. Similar analyses of some 

of the silt beds showed 75 percent finer than 0.075 

millimeter, 30 percent finer than 0.02 millimeter, and 

10 percent finer than 0.005 millimeter. Mechanical 

analysis of a sample collected by Sanchez from the silt 

and clay member south of the Traverse Mountains 

shows more clay than probably is typical of the member 

in that part of the valley. His sample, taken from the

upper 6 feet, contained the following (Sanchez, 1904, 

p. 17):

Mechanical analysis of clay, center sec. 27, T. 4 S., R. 1 E.

[Sample contained 29.2 percent calcium carbonate.]

Percent

Sand coarser than 0.10 mm__________________________ 3. 14

Sand 0.05 to 0.10 mm_-_._____._-__.________________ 12. 76

Silt 0.005 to 0.05 mm_____________.._____--_____-_ 33. 10

Clay 0.0001 to 0.005 mm____.___________-_____.- 50. 20

Chemical analyses for soluble salts in samples from 

the silt and clay member indicate that it contains on 

the average about one-half percent of such salts. 

The quantity appears to increase shoreward. (See 

table 13.)

BONNEVILLE FOBMATION

The Bonneville formation includes those deposits 

that accumulated in the lake during its highest stage, 

the stage that Gilbert (1890, pp. 93-125) referred to as 

the Bonneville stage.

The shoreline of the Bonneville stage is one of the 

most striking topographic features in the region, as is 

the high-water mark of any ephemeral pond. It is the 

boundary between two very different kinds of landforms, the higher of which is the product of fluviatile 

erosion, and the lower the product of lacustrine erosion 

and sedimentation.

But despite its prominence as a topographic feature 

the Bonneville stage is barely represented as a stratigraphic unit in the lake sediments. The Bonneville 

formation has been recognized only as a thin and discontinuous beach deposit along the high shoreline and 

in a spit at the Point of the Mountain. Elsewhere in 

the valley the formation has not been recognized and 

beds assigned to the Provo formation rest directly 

upon the Alpine formation.

In the vicinity of Provo some beds assigned to the 

Bonneville formation are sand, but elsewhere the 

formation is largely gravel. In the narrow discontinuous beach deposits along the front of the Wasatch 

Range and south side of the Traverse Mountains much 

of the gravel is shingled and only a few feet thick. 

It unconformably overlies the Alpine or older formations.

At the mouth of American Fork Canyon the gravel 

in the Bonneville formation is more rounded and less 

shingled than along the rest of the mountain front and 

forms a rather extensive sheet of gravel, 20 feet or more 

in thickness, resting on the Alpine formation.

Only at the Point of the Mountain is the Bonneville 

formation a considerable deposit. Here the formation 

is composed of gravel and sand that was deposited in a 

huge spit 300 feet high and extending 1 mile west from 

the end of the Traverse Mountains. In this gravel 

are granitic pebbles derived from the Wasatch Range
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 21

6 miles to the east. It is possible however that the 

voume of the Bonneville formation even in this spit is 

less than it appears to be, for we do not know the 

extent of the Alpine or other formations under the 

Bonneville in the spit.

Above the town of Alpine the Bonneville formation 

is derived from glacial out wash and, like the moraines 

there, is composed almost entirely of granitic sand, 

gravel, and cobbles. Evidently the glaciers were discharging large volumes of melt waters into the lake at 

the time the lake rose to its maximum height.

PBOVO FORMATION

Most of northern Utah Valley is covered by the 

Provo formation, which includes the deposits that were 

laid down while Lake Bonneville stood at what Gilbert 

(1890, pp. 126-134) called the Provo stage. The 

formation is divided into four members distinguished 

by their prevailing texture—gravel, sand, silt, or clay.

Along Dry Creek, below the town of Alpine, the 

Provo formation overlies glacial outwash which in 

turn rests on the Alpine formation (fig. 8). Locally, as 

at Pleasant Grove and in the western part of the valley, 

the Provo rests on pre-Lake Bonneville deposits and 

at these places the Alpine either was not deposited or 

was removed by erosion before the deposition of the 

Provo.

In most of the valley the Provo rests on the Alpine 

formation and in the interior of the valley the contact 

seems to be fairly regular. Along Jordan River, from 

the Narrows nearly to Utah Lake, the contact is along 

a smooth bedding surface. At the contact there commonly is a thin, lenticular layer of sand which may be 

a sandy facies of the glacial outwash. West of the 

Geneva Steel plant, however, outcrops and drill holes 

show that the contact there is undulatory through a 

vertical range of 13 feet in a horizontal distance of 

about 1,500 ft. (See fig. 7.)

Around the edge of the basin the contact, no doubt, 

has many irregularities. Near the north side of 

Highland bench, 2 miles southwest of Alpine, is a solitary hill rising above the delta surface. Gravel, sand, 

and silt that are grouped together as sand on the map 

(pi. 1), comprise the hill and are thought to be part of 

the Alpine formation. No contacts were found, but 

the hill is presumed to be more ancient than the delta 

which partly buries it.

Few vertebrate remains have been found in any of 

the Lake Bonneville formations, a fact noted by Gilbert 

(1890, p. 210). Articulated remains of mammoth, 

however, were found (Hansen, 1928) near Payson, in 

the southern part of Utah Valley, "* * * in a thin 

bed of fine clay fifteen feet below the surface of the 

terrace gravels of * * * the Provo stage * * *"

Gravel member.—The gravel member of the Provo 

formation occurs principally as delta deposits at the 

mouths of the large streams issuing from the Wasatch 

Range. It also occurs as littoral embankments between the deltas, as small bars in front of the deltas, 

and as a spit at the Point of the Mountain.

At the front of the deltas the thickness of the gravel 

member generally exceeds 100 feet. For -example, 

between Dry Creek and American Fork River, the 

bluffs in front of Highland bench are about 175 feet 

high; east of American Fork River they are 100 feet 

high; and west of Dry Creek they are 150 feet high. 

The bluffs at the west edge of Orem bench 1% miles 

southeast of the Geneva Steel plant are about 125 

feet high, although they are only 75 feet high at the 

north and south ends of the bench. These heights

N 

A

500 1500 Feet 

_I

FIGURE 7.—Contour map showing configuration of the base of the clay member of 

the Provo formation in part of sec. 7, T. 6 S., B. 2 E. Map based on the logs of 24 

holes drilled to test the reservoir site for the Geneva Steel plant. Drill holes shown 

by dots; elevation of base of Provo formation shown beside each hole.

provide an approximate measure of the thickness of 

the delta at its distal end because the bottomset beds 

in front of the delta are only 25 to 30 feet in thickness. 

The texture and degree of bedding in the gravel 

member vary with the position in the delta. Throughout the deltas the topset beds, presumably representing 

subaerial parts of the deltas, are poorly sorted, as are 

other fluviatile deposits. At the apex of the Highland 

bench and Orem bench deltas only the topset beds are 

exposed and their gravel deposits include many boulders 

a foot or more in diameter, the percentage of fines is 

low, the sorting is poor, and the bedding indistinct. 

Toward the distal ends of the deltas the topset beds 

thin and the foreset beds become distinct. In the
22 LAKE BONNEVILLE

foreset beds the proportion of fines is high, Many 

of the beds of gravel are composed of pebbles only 

% or 1 inch in diameter. Interbedded with these are 

beds of still finer gravel and sand; beds of cobbles are 

comparatively few. Sorting is excellent.

Gravels deposited by Provo River contain about two 

pebbles of quartzite for each pebble of limestone or 

dolomite-. (See fig. 15.) Gravels deposited by American Fork River include about as much limestone or 

dolomite as quartzite. The west part of Highland 

bench includes considerable granitic material con- 

• tributed by Dry Creek. There is considerable sand and 

silt with these gravel deposits with the result that 

the member, although permeable, is not excessively so. 

The high content of sand and silt is illustrated by the 

two following mechanical analyses reported by Sanchez 

and representing material he collected at localities 

that are on the deltaic gravel. Presumably he excluded 

stones larger than 2 millimeters in diameter (Sanchez, 

1904, pp. 11, 12):

Mechanical analyses of gravel member of Provo formation

Sand 0.25-2 mm______

Sand 0.05-0.25 mm___ 

Silt and Clay 0.05 mm.

Center north side NE. corner sec. 9,

sec. 8 T. 7 S., R. S T. 5 S., R. 1 E.

E. (0-50 inches) (0-40 inches)

15. 08 40. 50

45. 58

39. 40

42. 92

16. 60

The surface layers of the gravel member contain 

large quantities of calcium carbonate. Part of this 

calcium carbonate apparently was deposited at the 

top of a fluctuating water table; part seems to have 

resulted from surf action in Lake Bonneville. Very 

little of the calcification in these gravel deposits 

appears to be due to soil processes. (See p. 35.)

In both the Highland bench and Orem bench deltas 

the gravel constitutes a central facies that grades 

northwestward into a sandy facies, and southeastward 

into silt. The pebble drift indicates northerly currents along this eastern shore of Lake Bonneville, and 

the facies changes within the deltas suggest the same. 

The sand was carried north beyond the gravel while 

mud accumulated in what was probably a quiet eddy 

on the southwestern side.

In the old shore embankments between the deltas 

and at the spit at the Point of the Mountain gravel beds 

are similar to those at the distal ends of the deltas. 

Many of the beds are fine gravel and they contain a high 

percentage of fines; their sorting is excellent and their 

bedding distinct. The gravel mantles wave-cut terraces in the older deposits and lies against a steep 

slope of the older materials at the inner edge of the 

terrace. At the outer edge of the terrace, gravel was 

spilled onto the pre-lake slope and the terrace widened 

by deposition. Thus an embankment deposit may

be only a few feet thick where it lies on the flat surface 

of a wave-cut terrace, but it may be scores of feet thick 

where it has been constructed outward onto the old 

sloping surface.

The embankment deposits have the same internal 

structure as the deltas and resemble the deltas lithologically. Foreset beds slope obliquely toward the lake 

and show the direction in which the embankment was 

built. Topset beds truncate the foresets, and bottomset 

beds extend from the foot of the foresets.

Gastropod shells are rather plentiful in the gravel 

member where it forms the spit at the Point of Mountain, but elsewhere few shells have been observed in 

this member.

In front of the Highland bench the gravel member 

forms some small gravel bars; one of the best-formed 

ones is at the bend in the road near the center of the 

Sy2 , sec. 11, T. 6 S., R. 1 E. These bars extend northwest, and at their southeast ends they are connected 

with the delta front, indicating that they were deposited by northwesterly currents. Apparently they 

overlie silt or other fine-grained sediments.

Sand member.—The sand member of the Provo 

formation represents three kinds of deposits: deltaic 

deposits, bars in front of the deltas, and bottomset or 

foreset beds where the gravel member in embankments 

grades outward into the finer-grained lake bottom 

sediments.

In both the Highland bench and Orem bench deltas 

the sand member comprises a facies lying northwest 

of the gravel member and apparently represents sand 

that was winnowed from the gravel by northwesterly 

currents. The sand grains in these deltaic deposits are 

moderately rounded. Commonly the grains have 

plane sides, although the ends are round. Few have 

angular corners (fig. 4). Sanchez (1904, p. 15) made 

the following mechanical analysis of a sample taken 

from the north end of Orem bench:

Mechanical analysis of sand sample from center north side, sec. 

sec. 3, T. 6 S., R. 2 E.

0-S4 inches 24-72 inches 

Sand 0.10-2 mm________________________ 7.46 5.84

Sand 0.05-0.10 mm___-____-____--_____- 16.44 13.88

Silt 0.005-0.05 mm-__.____________-___-_ 40.44 39.80

Clay 0.0001-0.005 mm____ ______________ 35.32 39.72

The upper sample contained 3 percent, and the lower 

contained 13 percent of calcium carbonate. Like 

the gravel member in the deltas, this sand contains 

considerable silt and only in a few places is the ground 

excessively permeable or mantled by wind-blown 

sand.

Bedding in these sand deposits is fairly distinct. 

At the northwest end of Highland bench the sand, 

like the gravel interbedded with it, is in steeply dipping
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 23

foreset beds. At the north end of Orem bench, on 

the other hand, are many feet of almost horizontally 

bedded sand, probably topset beds. In that sandy 

part of the delta foreset beds were not found.

In front of the deltas are a series of sand bars. 

Those in front of Orem bench are several miles long, 

a few hundred feet wide, and a few feet high. They 

were deposited on lake-bottom silt and clay by currents 

that moved northward along the front of the delta. 

The road southward from the Geneva Steel plant to 

Provo is on the outermost bar. The bars in front of 

Highland bench are similar though less well developed. 

They contain more gravel than do those in front of 

Orem bench and they are lower, shorter, and wider. 

Some of the bars may have been built as shallow subaqueous features, some may have been built into 

beaches. Because they rest on the lake bottom silts or 

clays they must have been late in the Provo stage, 

probably while the ancient lake was shrinking to the 

level of Utah Lake.

No good cuts in these bars have been found, so their 

internal structure and the details of their composition 

are still inadequately known. Some grab samples 

from the bars in front of Orem bench indicate that the 

sand there is rather clean quartz sand, the grains are 

very well rounded (fig. 4) and the common size is less 

than 0.5 millimeter in diameter. At many places the 

wind has blown the sand into small dunes.

A mechanical analysis of a sample to a depth of 6 feet 

at the northeast corner sec. 28, T. 6 S., R. 2 E., was 

reported by Sanchez (1904, p. 12) to contain the 

following:

Mechanical analysis of sand from bar in front of Orem bench

	Percent 

Gravel 1-2 mm_____________________________________ 1. 96

Sand 0.5-1 mm_____________________________________ 10. 30

Sand 0.25-0.5 mm_ _________________________________ 20. 88

Sand 0.10-0.25 mm_________________________ 44. 98

Sand 0.05-0.10 mm_____________________________ 10. 52

Silt and clay 0.0001-0.05 mm__________________ 11. 36

The sand contains very little silt, clay, or calcium 

carbonate.

Where the gravel member forms a considerable embankment deposit, as at Camp Williams on the west 

side of Jordan River, the sand member forms a facies 

intermediate between the gravel in the embankment 

and the silt member that was deposited in the quieter 

water offshore. At these places the sand member 

forms the bottomset beds that extend lakeward from 

the foot of the gravelly embankments. Gastropods 

are abundant in these sand deposits that grade into 

the finer-grained lake bottom sediments.

The skull of a ground squirrel, identified by D. H. 

Johnson of the U. S. National Museum as Citellus

townsendii mottis, was found where the sand member 

overlaps pre-Lake Bonneville fanglomerate in sec. 32, 

T. 4 S., R. 1 E. This is a modern species widely distributed in the Great Basin. The skull evidently was 

washed in from the adjoining hills because nearby, but 

probably in the same bed, were found aquatic shells 

that were identified by Dr. Teng-Chien Yen, of the 

National Museum, as "embryonic shells and fragments 

of Valvata cf. V. utahensis Call."

Silt member.—The silt member of the Provo formation forms a part of each of the deltas, but is most extensive in a facies intermediate between the deltaic or 

other coarse shore deposits and the clays that accumulated in the interior of the old lake. The silt is 

gradational into the coarser-textured members and into 

the more finely textured clay member. The boundaries of the silt number as shown on the map (pi. 1), 

especially the boundary with the clay member, are arbitrary and based on rather superficial field tests. 

Systematic sampling and laboratory tests will be needed 

to map accurately the boundary between the silt and 

clay. Off the fronts of the deltas and embankments 

the silt, about 20 ft thick, is light gray, rather homogeneous, and is much less well bedded than is the silt 

member of the Alpine formation. Mechanical analyses 

of five samples of the silt are given in figure 13.

A mechanical analysis of a sample that apparently 

was taken from this part of the silt member, at a locality near Pleasant Grove, has been reported by 

Sanchez (1904, p. 17) as follows:

Mechanical analysis of silt member of Provo formation 

[Northeast corner sec. 20, T. 5 S., R. 2 E. Sample from 0-72 inches]

Percent 

Sand, 0.10-2 mm_________________________________ 0. 66

Sand, 0.05-0.10 mm_____________________________ 2. 92

Silt, 0.005-0.05 mm._____ —— _____------- — — — -— 23. 04

Clay, 0.0001-0.005 mm_____ —___ — ---- — -- — — — — 73. 20

Calcium carbonate._________________--___---__-----_ 16. 6

Fossil ostracodes and gastropods are rather abundant 

in the silt member in front of the deltas, especially in 

a layer about 1 foot above the base. In places this 

layer is almost a coquina.

A collection of ostracodes from the base of the silt 

member in the Denver & Rio Grande Western Railroad 

cut at the southeast corner sec. 26, T. 6 S., R. 1 W. 

were examined by Fred M. Swain who has identified 

the following species:

Candona cf. C. Candida (Muller) Common.

Candona cf. C. lactea Baird Common.

Limnicythere cf. L. sancti-patricii Brady and Robertson

Common.

Limnicythere cf. L. inopinata (Baird) Common. 

Limnicythere n. sp. aff. Cytheridea lacustris (G. O. Sars)

Abundant.
24 LAKE BONNEVILLE

According to Swain:

These species are Holarctic and typically are fresh-water 

lacustrine types, but Limnicythere [ inopinata has also been 

obtained from brackish tidal waters. Its presence might 

suggest that Provo Lake became slightly saline seasonally, 

but as the species also occurs in fresh water, such evidence is not 

conclusive. "Cytheridea" lacustris (Sars) (probably closer to 

Limnicythere), to which one of the forms from this locality is related, occurs both in fresh and brackish water. As Candona 

lactea seems to have been taken more often from rivers, its 

presence here may indicate that it was washed into Provo Lake 

by streams.

Gastropods associated with the ostracodes at the 

locality hi the railroad cut were submitted to Teng-Chien 

Yen, who indentified the folio whig species:

Amnicola longinqua Gould. 

Fluminicola cf. F.fusca (Haldeman). 

Lymnaea cf. L. utahensis Call.

Yen reports that these (species) are still living hi a 

large area west of the continental divide, including 

Utah, generally in shallow still water where there is 

a rich growth of vegetation.

A small jaw found in the silt west of Utah Lake, near 

the southeast corner sec. 12, T. 65., R. 1 W. was identified by C. L. Gazin, of the National Museum, as belonging to a pocket gopher, apparently in the group 

Thomomys talpoides.

Analyses for soluble salts in samples from the prodelta silt deposits indicate that they commonly contain 

a percent or so of chlorides, sulfates, and carbonates, 

and that the quantity of these salts increases lakeward. (See table 14.)

The silt member also is found hi the southern part 

of each of the deltas. Excavations on Highland 

bench show that the silt there is at least 10 feet thick— 

how much thicker is not known. The silt is light tan 

and massive. No fossil shells were found hi it. The 

origin of these silt deposits on the deltas is obscure. 

Perhaps they are water-laid sediments that were 

deposited in a bayou on the delta, and if so they are 

properly a part of the Provo formation. But their 

uniformly fine texture and indistinct bedding suggest 

that they might be windblown deposits; if this is correct 

they would be younger than the Provo.

Another deposit of the silt member is exposed along 

Dry Creek just below the town of Alpine. This 

deposit, about 6 feet thick, overlies glacial outwash and 

is overlain by post-Bonneville fluviatile deposits. 

The silt member is poorly bedded and contains considerable sand, and some thin lenses of granitic grit. 

The deposit seems to have been formed as a result of 

the ponding of Dry Creek when it was dammed by the 

gravels that were deposited across its course by American Fork River. The only fossils found in this silt are 

gastropods that have been identified by Teng-Chien

Yen as Succinea avara Say and Oreohelix strigosa 

depressa (Cockerell). Yen states that these are terrestrial snails and that both species still live hi the region.

The silt member commonly lies unconformably on 

the Alpine or older formations. Along Jordan River 

it overlaps the gravel member of the Alpine (pi. 1); 

at Pleasant Grove and at numerous places along the 

west side of the valley the silt overlaps pre-Lake 

Bonneville alluvial fans. In front of the deltas the 

silt is overlain by gravel or sand bars and by postLake Bormeville alluvial deposits.

Clay member.—The clay member of the Provo formation was deposited hi the interior of the lake. Like 

the silt member it ranges from 10 to 20 feet hi thickness, 

and is light gray and rather homogeneous. It also 

resembles the silt member in that it is indistinctly 

bedded.

Some mechanical analyses of the clay are given on 

figure 13. Other analyses made by engineers testing 

foundations for the Geneva Steel plant indicate that 

70 percent of the samples are finer than 0.02 millimeter 

in diameter, 45 percent are finer than 0.005 millimeter, 

and 10 percent are finer than 0.001 millimeter. Another 

analysis, reported by Sanchez (1904, p. 16), is as 

follows:

Mechanical analysis, in percent, of samples from the northeast 

corner of sec. 7, T. 6 S., R. 1 E.

(0-30 in.) (SO-7S in.) 

Sand, 0.10-2 mm______-_-_____-_------ 4.10 3.78

Sand, 0.05-0.10 mm.._______._____.._._ 1464 10.32

Silt, 0.005-0.05 mm-__-__________-_-_-_ 43.08 19.92

Clay, 0.0001-0.005-__-__-_-_-_--_------ 37.80 66.90

Calcium carbonate_-_____-________-_-__ 11.4 26.2

The part of the sample from 30-72 inches is probably 

from the clay member of the Provo formation; the top 

30 inches may be younger silt.

Ostracodes seem to be more abundant and gastropods fewer hi the clay than in the silt member. 

Commonly there is a concentration of shells about a 

foot above the base of the clay. Ostracodes collected 

from the clay member of the Provo formation by 

Utah Lake, 1 mile west of Geneva Steel plant, about 

the center of sec. 7, T. 6 S., R. 2 E. were examined by 

Fred M. Swain who identified the following: Candona 

sp. aff. C. Candida (Muller)—mostly broken fragments. 

Swain states:

This species is Holarctic in its distribution, and is found in 

Europe and North America. It occurs in almost every freshwater environment, and in some of the brackish, tidal areas of 

England and Europe. It prefers still water to running water.

In another collection from the base of the clay member along Jordan River, in sec. 1, T. 5 S., R. 1 W., 

Swain identified:

Candona cf. C Candida (Muller) Common.

Limnicythere n. sp. ? aff. Cytheridea lacustris (Sars) Common.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 25

A third collection of shells from a bed believed to be 

part of the Provo formation by Utah Lake in the NE% 

sec. 35, T. 5 S., R. 1 W. contains a variety of ostracodes 

and mollusks. Swain reported on the ostracodes as 

follows:

Candona cf. C. Candida (Muller) Abundant.

Candona cf. C. lactea Baird Common.

Cypridopsis sp. Rare.

Limnicythere sp. aff. L. inopinata (Baird) Rare.

Limnicythere n. sp. ? aff. Cytheridea lacustris (Sars) Rare.

Cytheridea cf. C. torosa (Jones) Very abundant.

He states:

The faunule is Holarctic. Candona lactea may have been 

washed in by streams. Cytheridea torosa has been taken in 

fresh water, but seems to be found more typically in a brackish 

to nearly normally saline environment. Its presence in such 

abundance suggests that the prevailing environment was more 

or less saline. Seasonal changes might account for the presence 

of the other more typically fresh-water forms. Hoff (The 

ostracods of Illinois, Illinois Biol., Monographs, Univ. Illinois 

Press, 1942, p. 33) says that many of the modern nonmarine 

forms are seasonal, the eggs deposited in one season remaining 

attached to some substratum, usually plants until the next 

favorable season.

Dr. T. C. Yen reported on the mollusks as follows: 

Sphaerium pilsbryanum Sterki. 

Pisidium sp. undet. 

Valvata utahensis Call. 

Amnicola sp. undet. 

Fluminicola fusca (Haldeman). 

Pompholopsis cf. P. whitei Call. 

Carinifex newberryi (Lea). 

Lymnaea utahensis Call. 

Physa lordi Baird. 

Physa cf. P. ampullacea Gould.

He states:

Practically all the identifiable species are found, according to 

the known records, in the Recent fauna of the Utah Lake and 

therein a similar assemblage of species may be found, so that the 

environmental conditions were much the same as they are now. 

The habitat suggested is that of a rich aquatic shore vegetation, 

possibly a somewhat marshy area.

Soluble salts are more abundant in the clay than in 

the silt member and their quantity increases lakeward. 

Moreover, the clay member of the Provo formation 

contains about twice as much soluble salts as does the silt 

and clay member of the Alpine formation. (See p. 33.)

The clay member of the Provo formation lies unconformably on the Alpine formation and is overlain 

by Post-Lake Bonneville alluvial deposits. West of 

the Geneva Steel plant the base of the clay member of 

the Provo is undulatory (fig. 7), and the nearly horizontal clay overlies beds of the Alpine formation which 

dip rather steeply to the east. The irregularities in 

the contact presumably reflect structural or erosional 

irregularities in the upper surface of the Alpine, rather 

than bars or other constructional features at the top of 

that formation.

CONCEALED PLEISTOCENE DEPOSITS

Nearly all wells drilled in the valley penetrate the 

Lake Bonneville group to obtain water from the 

underlying gravels or sand of the pre-Lake Bonneville 

Pleistocene deposits. Most of these wells are flowing 

wells drilled in the lower parts of the valley where the 

Alpine, Bonneville, and Provo formations are represented by clayey deposits, and these impermeable 

beds of fine texture confine the water under artesian 

pressure in the pre-Lake Bonneville deposits.

Drillers' logs of wells indicate that the clay deposits 

are relatively thin in the northeastern part of the 

valley, along the flank of the Traverse Mountains, and 

become thicker to the south. Section F-F' on plate 4, 

a geologic section parallel to the base of the Wasatch 

Range, is based on well logs, and shows that the Lake 

Bonneville group increases in thickness from about 25 

feet near Lehi to 160 feet near Provo. Other geologic 

sections indicate that within the area of well construction the clay and silt deposits are thickest in the 

interior of the valley and become progressively thinner 

toward its eastern edge.

The logs tabulated below show some of the characteristics of the concealed Lake Bonneville and older 

deposits in Utah Valley. The wells are located respectively on the recent alluvial fans of Dry Creek, 

American Fork River, and Provo River. The deposits 

of the Lake Bonneville group in each well are predominantly clay, but some sandy or gravelly beds are 

included in the section, and some of these are interpreted to mark the contact between the Provo and 

Alpine formations.

The well number indicates the location of the well 

with reference to land subdivision according to a system 

adopted by the Utah State Engineer and described in 

his Twentieth Biennial Report, p. 87, 1936. Briefly, 

the State is divided into four quadrants by the Salt 

Lake base and meridian, and these quadrants are 

designated by capital letters: A for the northeast 

quadrant, representing townships north and ranges 

east; B for the northwest quadrant; C, the southwest; 

and D, the southeast. In the well number the designation of the township is enclosed in parentheses and 

includes one of these letters, a figure showing township, 

and a figure showing range. In the number of the well 

here cited the portion within parentheses indicates 

that the well is in T. 5 S., R. 1 E. The number following the parentheses designates the section, and 

the lower-case letters following the section number 

give the location within the section, quarter-section, 

and sixteenth section (the letters q,, b, c, and d .representing the northeast, northwest, southwest, and 

southeast quarters of each subdivision). The final 

number designates the particular well within the 10-
26 LAKE BONNEVILLE

acre tract. Thus, number (D-5-1) 8dcc-l (see 

below) represents well 1 in the SW%SW%SE% sec. 8, 

T. 5 S., R. 1 E.

Driller's log of Lehi Irrigation Co. well (D-5-1) 8dcc-l

[State claim no. 11094. Unused well drilled 240 feet deep in June 1934 by F. G. 

Farris. Elevation of land surface at well, 4,555 ft]

Post-Provo deposits (Recent and Pleistocene ?)

Aluvium (Recent) (7 feet) :

Gravel ___---__------_-_________-_

Sand and gravel- _ _________________

Lake Bonneville group (Pleistocene) :

Provo formation (18 feet) :

Clay, light-gray. __________________

Clay and graveL __________________

Alpine formation (54 feet) :

Clay, brown _ ____________________

Sand and graveL __________________

Clay, sandy, blue_ _________________

Pre-Lake Bonneville deposits (Pleistocene) :

Shallow artesian aquifer (29 feet) :

Gravel, water-bearing ______________

Clay_ ____________________________

Clay and boulders ___•______________

Gravel, water-bearing ______________

Lacustrine (?) clay (45 feet):

Clay, yellow. _____________________

Clay and gravel- __________________

Intermediate artesian aquifer (71 feet) : 

Gravel, water-bearing ______________

Clay, yellow. _____________________

Gravel, water bearing, _____________

Clay, yellow- _____________________

Gravel, water-bearing ______________

Thickness Depth

(feet) (feet)

3 3

4 7

13

5

12

3

39

20

25

37

40

79

Sand, water-bearing, 

Lacustrine (?) clay:

Clay, sandy__ _ _____

Clay, blue_ ________

7

4

9

9

34

11

21

4

12

5

12

8

19

86

90

99

108

142

153

174

178

190

195

207

215

234

240

Driller's log of Drought Relief Adm. well (D-5-1) 10 cab-1

State claim no. 8308. Unused well drilled 400 feet deep in October 1934 by F. G. 

Farris. Elevation of land surface at well, 4,661 feet]

Driller's log of Drought Relief Adm. well (D-5-1) 10 cab-1— 

Continued

Pre-Lake BonneviJle deposits (Pleistocene)—Continued

_ -. ,. •!./»!.» ,\ Thicknses Depth Intermediate artesian aquifer (75 feet): (feet) (feet)

Gravel and clay__------_------------ 36 245

Gravel, water-bearing._______________ 6 251

Clay-___--_-_-______._____--_------ 3 254

Gravel, water-bearing________________ 18 272

Gravel and clay_----___----_-------- 12 284

Lacustrine (?) (74 feet):

Clay-_----_-_____---_-_---_-----_-_ 23 307

Clay and graveL ____________________ 15 322

Clay----__-_-_--_-----_-----------_ 18 340

Sand and clay__-_-_--------^----_-_- 4 344

Clay______________-__-_-_---_______ 8 352

Sand and clay___--_-------_-_-_---_i 6 358

Deep artesian aquifer:

Boulders and clay------------------- 20 378

Clay, yellow_-_-__-_-_-_---_-_____ 2 380

Boulders and clay_----_-----_---_-___ 2 382

Clay_________--_----------------__- 2 384

Clay and sand-__-__-_-__-_-_-_--____ 12 396

Clay___________-_________________ 4 400

Driller's log of Jacobson and Smith well (D-7-2) 12cdb-2

[State application no. 12866. Irrigation well drilled 226 feet in July 1939. Elevation 

of land surface at well, 4,509 feet]

Post-Provo deposits (Recent and Pleistocene?):

AH • f-o i\ /AC. t i\ Thickness Depth Alluvium (Recent) (45 feet): (feet) (feet)

Soil____-___-_____-_________________ 4 4

Gravel, coarse___________-_____--____ 41 45

Lake Bonneville group (Pleistocene): 

Provo formation (35 feet):

Clay, blue__________-_-___--_--_____ 25 70

Sand._____.______________________ 10 80

Alpine formation (84 feet):

Clay, blue________-___-___-__-____-- 34 114

Gravel___________-_-_-__--___-_--__ 10 124

Clay, blue-___________-____--_-_-_-_ 40 164

Pre-Lake Bonneville deposits (Pleistocene): 

Shallow artesian aquifer:

Gravel-______-_-_-_-_---------_____ 16 180

Clay___________________________-__- 36 216

Gravel, water-bearing._______________ 10 226

Post-Provo deposits (Recent and Pleistocene ?):

Alluvium (Recent) (41 feet):

Soil._____---__--___________--_____

Sand. _____________________________

Lake Bonneville group (Pleistocene):

Provo formation (33 feet):

Sand, fine._________________________

Clay, sandy________________________

Sand and fine gravel- _______________

Alpine formation (28 feet):

Clay..____________________________

Clay and sand______________________

Pre-Lake Bonneville deposits (Pleistocene):

Shallow artesian aquifer (47 feet):

Gravel and boulders_________________

Lacustrine (?) clay (60 feet):

Clay, yellow._--_--_-_-____________

Clay and sand____ __________________

Thickness 

(feet)

33

7

15

11

20

47

17

43

Depth 

(feet)

41

48

63

74

94

102

149

166

209

The log of the Orem city well shows that the thickness 

of the Lake Bonneville group under the Orem bench 

may be about 210 feet. The deltaic gravel and sand 

of the Provo formation has a total thickness of about 

120 feet and rests upon the clay member of the Alpine 

formation, 90 feet thick.

Driller's log of Orem city well (D-6-8) llbcc-1

[State application no. 17238. Municipal well drilled 469 feet deep by L. W. Dalton In 

March 1946. Elevation of land surface at well about 4,782 feet]

Lake Bonneville group (Pleistocene): 

Provo formation (117 feet):

Cobbles and gravel (perched water)____ 

Clay, blue__________________________

Quicksand (perched water)____________

Alpine formation (90 feet):

Clay, blue __________________________

Thickness 

(feet)

54

20

43

90

Depth 

(feet)

54

74

117

207
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 27

Driller's log of Or em city well (D-6-%) llbcc—Continued

Pre-Lake Bonneville deposits (Pleistocene): 

Shallow artesian aquifer (141 feet): 

Clay and gravel-_______________

Sand, coarse.___________________

Boulders and sand______________

Clay, yellow.__________________

Sand __________________________

Lacustrine(?) clay (61 feet):

Clay, yellow; some sand _________

Clay, blue _____________________

Clay, yellow.__________________

Clay, blue.____________________

Intermediate artesian aquifer: 

Boulders; some clay.

Thickness 

(feet)

31

9

81

9

11

19

30

4

8

27

33

Depth 

(feet)

238

247

328

337

348

367

397

401

409

436

Boulders, gravel, sand; water-bearing_ 469

GLACIAL DEPOSITS

Glacial deposits in northern Utah Valley are of two 

kinds: moraines and outwash sediments. Two moraines 

are exposed at the mouth of Alpine Canyon, about 2% 

miles northeast of the town. Outwash from the 

morainal deposits crops out along Dry Creek and 

extends at least a mile southwest of Alpine.

MORAINES

Atwood examined the glacial basin and moraines in 

Alpine Canyon and has given the following description 

of them (Atwood, 1909, pp. 78-79).

The white granite walls about the basin are smoothed and the 

loose material of the slopes have been largely cleaned away. 

Roche moutonnee surfaces are common about the head and on 

the slopes of the valley. The catchment basin and the valley 

below show signs of vigorous ice action, resulting from a gradient 

of more than 1,000 feet per mile, over which the glacier descended.

The lower part of the valley contains a large amount of drift. 

Lateral moraines lie high on the slopes, and the outer and upper 

two on either side appear much older than those within and 

below. Their greater age is shown not only by their position 

but by the relatively large amount of erosion and disintegration 

which they have suffered.

The material of the outer moraines is so disintegrated as to 

form a thick mantle of soil, while the inner and lower deposits 

show an insignificant amount of postglacial weathering. Many 

of the crystalline rocks on the surface of the outer moraines have 

crumbled. Others are about ready to crumble and fall to pieces 

if struck with the hammer. The surface boulders of the inner 

series of moraines are so fresh that striae are preserved on their 

surfaces. They appear not to have been in the least affected 

by weathering.

The contrast in age between the two series of moraines is also 

shown by the more numerous and deeper erosion lines in the 

outer series. The more recent deposits show but insignificant 

gully lines, while the outer moraines are considerably dissected.

These facts, strengthened by similar data from other canyons, 

justify the following conclusions:

(1) That there were at least two distinct glacial epochs in the 

region; (2) that, so far as thickness of soil may furnish a basis 

for estimating time, the interglacial period was much longer 

than that which has elapsed since the last retreat of the ice; (3) 

that during so long an interglacial period a notable amount of 

247743—53———3

erosion must have taken place; (4) that the ice of the earlier 

period was more extensive than the ice of the later period.

The difference in the soil that has formed on the two 

deposits, as noted by Atwood, is indeed striking. The 

parent material in both moraines is largely granitic. 

On the older moraine reddish-brown sticky clay has 

developed in the upper layers of the soil to a depth of 

at least 2 feet. Beneath this is another 2 feet of yellowish-brown, but clayey, sand and grit. In both 

these layers the granite pebbles are rotten and easily 

crushed in the hand. Beneath these layers is about 3 

feet of sand and grit containing weathered but comparatively firm granite pebbles and cobbles, and below 

this is a zone containing tiny veinlets of lime carbonate. 

On the younger moraine fresh boulders are abundant 

at the surface. Only locally has clay been formed at 

the surface, and this is very sandy and light-colored 

compared to the clayey layers at the surface of the old 

moraine.

No exposure was found of the contact between the 

two moraines. There is little, therefore, to add to 

Atwood's conclusions or to the evidence on which he 

based his conclusions. It should be noted however 

that the deep soil on the old moraine is not valid evidence that the interglacial period was longer than the 

time that has elapsed since the last retreat of the ice. 

That soil is the product of past climates that may have 

been utterly unlike the climate that has prevailed since 

glacial time. Indeed there is reason to question whether 

so deep a soil could be developed on hillside environments under the feeble processes of the present climate. 

(See p. 45.)

The older moraine seems to have been displaced about 

100 feet along the fault that crosses Dry Creek 2 miles 

northeast of Alpine. The younger moraine did not 

reach quite to the fault, but the outwash from that 

moraine does not appear to be faulted.

Atwood (1909, p. 79) indicated that the Alpine Valley 

glacier advanced a mile beyond the Bonneville shoreline, but this is incorrect. The distinctly morainal 

ridges end below the canyon mouth but a mile upstream 

from the Bonneville shoreline, which here is an ill-defined feature and probably was incorrectly identified 

during his reconnaissance.

Despite the fact that Alpine Valley traverses Paleozoic sedimentary formations as well as the granite of 

the Little Cottonwood stock, the moraines and glacial 

outwash are composed very largely of granitic materials, because the glaciers headed on the granitic, 

north side of the valley.

Other glacial moraines are farther up Alpine Canyon 

and in the headward parts of American Fork River and 

some tributaries of Provo River.
28 LAKE BONNEVILLE

GLACIAL OUTWASH

Glacial outwash from the younger of the glaciers 

that reached the mouth of Alpine Canyon fills the 

valley of Dry Creek from the mouth of the canyon to 

approximately the shoreline of the Bonneville stage 

and is exposed intermittently farther downstream 

where it rests on the Alpine formation and is overlain 

by the Provo formation. The glacial outwash is composed very largely of granitic material and is readily 

distinguished from the other fluvial gravels along Dry 

Creek which contain only about 30 or 40 percent 

granitic pebbles.

Near the mouth of Alpine Canyon boulders 6 feet 

in diameter are abundant in the outwash. At the 

Bonneville shoreline the large boulders are commonly 

about a foot in diameter. The Bonneville formation 

here is composed very largely of granitic material and 

apparently was built of the outwash from the younger 

moraine.

The outwash above the shoreline undoubtedly overlaps the old pre-Lake Bonneville alluvial fan that was 

built by Boxelder Creek, a canyon south of Alpine 

Canyon, but the contact between these two deposits 

was not found. The fanglomerate that overlies the 

outwash immediately south of Dry Creek is 40 feet 

thick and contains no granitic material. It is believed 

to be outwash from a moraine high in the next valley 

south of Dry Creek.

Farther down Dry Creek from the shoreline of the 

Bonneville stage the outwash is largely concealed by 

alluvial deposits. The outwash is exposed near the 

mouth of Fort Canyon in the NE% sec. 24 and in 

the south wall of Dry Creek half a mile below Alpine. 

This latter locality is particularly revealing, for the 

outwash, 6 feet in thickness, can be traced downstream 

under the gravel member of the Provo formation and 

on top of the Alpine formation. The glacial outwash 

is quite distinctive because of its high content of 

granitic pebbles, whereas the gravel member of the 

Provo formation, here derived mostly from American 

Fork Canyon, is composed almost entirely of limestone 

or quartzite pebbles—50 or more of these to 1 of 

granite.

The glacial outwash has not been recognized in the 

interior of the valley and evidently the gravel facies of 

the outwash did not extend far down Dry Creek. The 

contact between the Alpine and Provo* formations 

along Jordan River, however, commonly is marked by 

a few inches of loose clean sand that may be a sandy 

facies of the outwash.

ALLUVIAL DEPOSITS OF PROVO (?) AGE

Some of the flood-plain deposits at Alpine and along 

Dry Creek upstream from the town probably were 

deposited during Provo time, but they are not shown

separately on the map (pi. 1) because they cannot be 

distinguished satisfactorily from the younger alluvial 

deposits that partly mask them. These old alluvial 

deposits overlie the outwash from the moraine and 

they were probably laid down during Provo time.

The flood-plain deposits on which the town of Alpine 

is built probably are very largely correlative with the 

Provo formation. During Provo time American Fork 

River built its delta northwestward across Dry Creek 

about a mile below Alpine, and this seems to have 

dammed Dry Creek. The dam is composed only of 

topset beds and probably is largely of subaerial origin. 

The deposits upstream along Dry Creek are entirely 

of fluviatile origin (see fig. 8), and overlie the outwash

Floodploin -de posits Grove) member of

FIGURE 8.—Diagrammatic section tor about 2 miles along Dry Creek at Alpine. 

The glacial outwash is from the younger of the moraines at the mouth of Alpine 

Canyon. It rests on the Alpine formation and is overlain by the gravel member 

of the Provo formation derived from American Fork River. The flood-plain deposits on which the town of Alpine is built are believed to have been formed when 

Dry Creek was dammed by the gravels from American Fork River.

from the younger of the moraines at the mouth of 

Alpine Canyon. The surface of the Dry Creek floodplain is 1 or 2 feet lower than the surface of the delta, 

and its base is 20 to 25 feet lower.

POST-PROVO DEPOSITS (PLEISTOCENE(?) AND RECENT) 

ALLUVIAL DEPOSITS

Post-Provo flood-plain deposits are rather widespread 

along Provo River, American Fork River, and Dry 

Creek. These fluviatile deposits are gravelly and, like 

the topset beds on the deltas, are characterized by poor 

sorting, and indistinct and lenticular bedding.

Most noteworthy of these deposits is the large fan, 

mostly gravel, built on the clay and silt members of 

the Provo formation where American Fork River issues 

from Highland bench. At the town of American Fork 

this deposit is about 50 feet thick. It is 3 miles wide 

and thins radially southward from the town. The 

central part of the fan is composed of gravel. Around 

the fringe, and below about the 4,550-foot contour the 

fan is overlain by recent lacustrine silt which, however, 

is not differentiated on the map (pi. 1). The gravel 

in the fan is the kind transported by American Fork 

River, mostly limestone and quartzite. They are wellrounded but poorly sorted. Unlike the lake-deposited 

gravels only small amounts of secondary calcium 

carbonate have accumulated in the surface layers of 

this alluvial gravel despite the abundance of lime in 

the parent material. Sanchez (1904, p. 15) gives the 

following mechanical analysis of a sample he collected 

near the west edge of the gravel facies of this fan:
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 29

Mechanical analysis, in percent, of alluvium in center of sec. 23, 

T. 5 S., R. 1 E.

(0-30 inches) (30-60 inches')

Sand, 0.10-2 mm.__.__...___._.___ 15.04 7.58 

Sand, 0.05-0.10 mm..____._________ 19.46 19.48

Silt, 0.005-0.05 mm...____________ 41.00 44.00

Clay, 0.0001-0.005 mm__..__._.._______ 24.40 28.70

Calcium carbonate_____-____________.__ 39.6 47.2

At Lehi is another alluvial fan, built by Dry Creek 

on the lake-bottom clay or silt beds belonging to the 

Provo formation. This fan is about 30 feet high and 

about 2 miles wide. Within a few feet of the surface, 

the fan contains little gravel, and is composed mostly 

of fine sand and silt. These fine-grained sediments 

may be, in part, a lacustrine deposit overlying the 

alluvial material of the fan. Well logs (pi. 4, sec. F-F') 

suggest that the alluvial deposits may have a maximum 

thickness of about 50 feet, probably because of channeling into the underlying Lake Bonneville group.

Provo River has a wide gravel flood plain, and much 

of the town is built on silty beds, presumably lacustrine, 

that overlie the gravel. The Provo R ver fan is only 

about 15 feet high. Well logs show (pi. 4, sec. F-F') 

that channels have been cut into the Lake Bonneville 

group at least as far downstream as th3 city of Provo, 

and that these channels have been fil ed with coarse

gravel and sand. The maximum thi 

post-Provo alluvial deposits, according 

about 40 feet.

These three fans are composed o 

worked from the deltas. As the level 

ville fell, Dry Creek, American Fork R 

River became incised in the unconsolidated deltaic 

deposits and the material removed from their channels 

was deposited in the fans.

Other post-Provo alluvial deposits ar

nizable along the front of the Lake Mountains. These

deposits are narrow and thin, generally

thick, and are distributed along the gullies and other

stream courses that descend the fans at

mountains. Between these trains of very recent 

gravel and boulders are the undisturbed Lake Bonneville group and pre-Lake Bonneville a [uvial deposits.

Other similar alluvial deposits overl 

old fans around the edges of the valle; 

incompletely shown on the map. EL

valley the post-Provo alluvial deposits are small.

EOLIAN(?) SILT

Not shown on the map is a layer of 

a few inches to 1 foot or more in thickness 

extensive areas in the upper bench* 

slopes in the valleys. This silt is pj 

spicuous where it overlies gravel depos 

the deltas of the Provo stage. It is

kness of these 

to well logs, is

materials ref Lake Bonne.- 

ver and Provo

readily recogonly a few feet

the foot of the

e many of the 

r, but they are 

ewhere in the

silt ranging from 

that blankets 

s and hillside 

rticularly conts like those in 

c ark brown and

rather homogeneous in texture, although at most 

places it contains a few pebbles like those in the underlying gravel. Locally it is free of pebbles but rather 

sandy. The lower part of the silt contains considerable 

carbonate but the top inch or so generally has been 

leached of its carbonate.

The silt appears to be a stratum distinct from and 

younger than the underlying gravel. It is nearly 

free of pebbles at places where the underlying gravel 

includes much quartzite so it is assuredly not a residual 

effect of weathering of the gravel. Moreover, the 

contact between the silt and underlying lime-cemented 

gravel commonly is sharp. The silt probably is largely 

an eolian deposit blown onto the higher parts of the 

valley when the old lake level fell and the lake-bottom 

sediments became dessicated. If so it has been considerably reworked, both artificially and naturally. 

Many of the pebbles in it perhaps were heaved upward 

by frost action.

LAKE DEPOSITS

In the bottom of Utah Lake is sediment that spans 

all the time that has elapsed since the Provo formation 

was deposited. Although lake sediments younger 

than the Provo formation have not been recognized 

around the shores of the present lake it is very possible 

that Utah Lake has risen as high as the 4,550-foot 

contour since Provo tune, because below that level 

the alluvial fans at Lehi, American Fork, and Provo 

are overlain by silt that may be of lacustrine origin.

VERTEBRATE FOSSILS

Deposits presumed to be post-Provo in age have 

yielded mammoth remains at two localities in Utah 

Valley. One locality was in a marsh near the eastern 

shore of Utah Lake a few miles south of Provo (Gilbert, 

1890, p. 211). Another was near the city of Provo in 

gravel below the level of the Provo stage (Blackwelder, 

1939, p. 892). The stratigraphic positions of the bones 

are not known. The localities are below the level of 

the Provo stage, and presumably the deposits that contained the bones are post-Provo in age. But the positions could not be below the Stansbury level (Blackwelder, 1939, p. 892) because the Stansbury was at or 

below the level of Utah Lake. Probably the mammothbearing deposits are little if any younger than the 

Stansbury stage. It is doubtful that any of the extinct 

animals that characterize the Pleistocene survived 

much longer than Stansbury time in the Lake Bonneville basin. At least no representatives of the extinct 

species have been found among the plentiful vertebrate 

remains collected from post-Stansbury deposits in the 

Great Salt Lake region (Stewart, 1937, pp. 81-82, 102, 

118).
30 LAKE BONNEVILLE

R.I W R.I E R.2E. R.3E.

EXPLANATION

Sample from onshore deposit

Sample from near-shore deposit

Sample from offshore deposit

Numbers refer to analyses given In text. 

For comparative purposes the samples 

are grouped as shown by the connecting 

lines

Samples I to 12 are from the Provo formation-, samples 13 to 18 are from the 

Alpine formation

UfcL PLEASANT 

GROVE

FIGXIBE 9.—Sketch map showing location of samples collected for chemical analyses.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 31

SOME QEOCHEMICAL PROBLEMS

ANALYSES AND OUTLINE OF SOME OP ^THE PROBLEMS

During a field conference in Utajh Valley, Dr. 

Vladimer P. Sokoloff suggested testing the Lake Bonneville deposits to determine whether variations in 

their chemistry might be correlated with the paleogeographic conditions of deposition. It wlould be reasonable to suppose, for example, that the quantity and 

kind of soluble salts in the sediments would vary in an 

orderly way depending on the properties of each salt 

and the variations in conditions of sedimentation from 

one part of the lake basin to another.

As a first test of the hypothesis numerous field qualitative analyses were made for calcium, magnesium, 

sodium, potassium, carbonate, chloride, and sulfate. 

As orderly variations were found in the distribution of 

some of these constituents, a series of samples was 

collected for quantitative analyses. ^Eighteen complete rock analyses and 18 partial analyses for watersoluble salts were made by Norman Davidson, Margaret 

Foster, and W. W. Brannock in the chemistry laboratory of the Geological Survey. The analyses are 

given in tables 4 to 7. Figure 9 shows the localities 

from which the samples were collected.

The samples were collected from the Alpine and 

Provo formations at localities that w6uld provide a 

basis for three kinds of comparison^: comparisons 

between similar and contemporaneous^ deposits that 

had different sources; comparisons between similar

TABLE 4.—Complete analyses of silt and clay from Provo formation 

northwest of Dry Creek

[Analyses by Norman Davidson and W. W. Brannock, chemists, U. S. Geological

Survey]

SiOi...- —— — —

AhOs- — —— ———

Fe8Oi>. ------- .-

MgO___.- — —— -

CaO. — — ————

NajO.— —— — -

KjO..— - — — - -

HjO-... — ———

HjO+... —— — —

TiOi— ---------

COa.—— ..........

P,0j._ — .... .... -

SOs— — ---------

Cl._ ._-- —— ---

MnO. . -------

NiO. ..............

Se.....- — — ---

Near-shore deposits

1

50.4 

8.9 

2.9 

2.9 

13.0 

1.8 

1.7 

2.4 

2.3 

.5 

11.1 

.2 

.6 

.9 

.1 

0 

0

99.7

2

54.4 

11.3 

4.0 

2.1 

9.8 

1.5 

2.0 

3.7 

3.1 

.5 

6.7 

.2 

.4 

.2 

.1 

0 

0

100.0

Offshore deposits

3

52.6 

11.1 

3.6 

2.9 

10.4 

.7 

2.2 

3.1 

3.7 

.4 

8.1 

.2 

.4 

.1 

.1 

0 

0

99.6

4

51.4 

9.3 

3.0 

3.1 

13.3 

1.3 

1.8 

2.1 

1.6 

.5 

11.2 

.2 

.4 

.3 

.1 

0 

0

99.6

— 1

5

49.6 

9.9 

3.3 

3.4 

13.0 

1.5 

2.2 

2.0 

1.8 

.5 

11.2 

.3 

. o

:i

0 

0

100.0

6

48.3 

10.2 

3.3 

3.8 

14.1 

1.1 

1.8 

1.8 

2.1 

.4 

12.8 

.2 

.2 

.4 

.1 

0 

0

100.6

7

45.2 

9.6 

3.3 

3.1 

15.8 

1.1 

1.8 

2.3 

2.1 

.5 

13.3 

.2 

.9 

.7 

.1 

0 

0

100.0

1 Ferrous iron not determined because of the presence of organic matter.

1. 1,000 feet east of center, sec. 26, T. 4S., R.I W. From basal 24 inches of formation.

2. Wall of ditch by Camp Williams road. Just west of southwest corner sec. 35, 

T. 4 S., R. 1 W.

3. West of center sec. 11. T. 5 S., R. 1 W. 42 inches below surface.

4. D &ROW RR cut. Northwest corner sec. 36, T. 4 S., R. II W. Sample cut from 

3 feet in lower part of formation. Base of sample about 1 foot above base of formation.

5. Lower 4 feet of formation, about 6 feet below surface. >NEJ£NWK sec. 1, T. 

5 S., R. 1 W.

6. Center NWJi sec. 12, T. 5 S., R. 1 W. Basal 4 feet of formation about 7 feet 

below surface.

7. SWJ^NWJi sec. 13, T. 5 S., R. 1 W; 3-foot sample about 1 foot above base of 

formation.

facies that were derived from the same source rocks 

but at different times and presumably under different 

conditions; and comparisons between near-shore and 

offshore deposits that had a common age and source.

Some comparisons also can be made between the 

water-soluble salts contained in the Lake Bonneville 

sediments and the salt content of modern Lake Utah. 

Some analyses of Utah Lake waters are given in table 8.

TABLE 5.—Complete analyses of silt and clay from Provo formation 

southeast of American Fork River

[Analyses by Norman Davidson and W. W. Brannock, chemists, U, S. Geological

Survey]

SiOa— —__ —— —— —— -

AljOs— ——- —— — - —— -

FejOi '...—. — — ......

MgO..— — —— --._--

CaO. r . . ——— — - ——— I

NajO— -- — — - — — -

KtO.......... .............

H»O-.... ................ .

H»0+— — — — — — —

TiOa— — ------------

CO....——— — —— — .„

PjOs.. - ------------------

SOj... — .- —— —— —— -.

Cl.._—— _---_ —— -_--

MnO..— ---------------

NiO...— —— —— —— —

Se— -------------------

Onshore( ?) 

deposit

8

49.7 

10.2 

3.6 

2.9 

13.8 

.9 

1.4 

1.2 

3.3 

.6 

11.4 

.2 

.2 

.2 

.1 

0 

0

99.7

Nearshore 

deposit

9

50.1 

5.3 

2.3 

4.5 

16.7 

.4 

1.4 

.2 

1.3 

.3 

16.4 

.2 

.2 

.2 

.1 

0 

0

99.6

Offshore deposits

10

52.8 

11.1 

3.5 

2.2 

12.1 

.4 

1.7 

2.1 

3.2 

.6 

9.2 

.3 

.2 

<.l 

.1 

0 

0

99.5

11

45.1 

7.7 

3.0 

3.8 

17.0 

.8 

1.7 

1.5 

2.5 

.5 

15.4 

.3 

.3 

<.l 

<•! 

0 

0

99.6

12

46.8 

7.7 

2.7 

3.1 

15.8 

1.5 

2.0 

2.5 

2.2 

.5 

13.6 

.2 

.5 

.6 

<-l 

0 

0

99.7

1 Ferrous iron not determined because of the presence of organic matter.

8. On Highland Bench, east quarter corner, sec. 7, T. 5 S., R. 2 E. Sample 42 

inches below surface.

9. Center of NEJi sec. 18, T. 5 S., R. 2 E.

10. 40 inches below surface. Center of west side SW^f sec. 20, T. 5 S., R. 2 E.

11. 40 inches below surface. Center of west side, sec. 29, T. 5 S., R. 2 E.

12. Center of south line, sec. 31, T. 5 S., R. 2 E; 36 inches below surface.

TABLE 6.—Complete analyses of silt and clay from Alpine 

formation

[Analyses by Norman Davidson, chemist, U. S. Geological Survey]

SiOi- — -------

AljOj— ----------

FeaOi i... --------

MgO. — -------

CaO— --------

NaiO—— ----------

KjO— —— —— —

HiO- — — — ——

HjO+— —— . — —

TiOa—— . -. -------

COS -_ — --------

PaOj— .— —— ——

SOj— ----------

C\... ............ ...

MnO-. — ------

NiO— ---------

Se..— — -— — .

Total———-

Near-shore 

deposits

13

41.9 

10.7 

2.3 

5.1 

16.3 

.7 

1.9 

1.8 

2.3 

.4 

16.3 

.2 

.1 

.2 

.1 

0 

0

100.3

14

43.4 

10.4 

3.2 

4.5 

15.7 

1.2 

2.1 

1.1 

2.6 

.5 

15.0 

.3 

.1 

.4 

.1 

0 

0

100.6

Offshore deposits

15

45.2 

11.2 

3.5 

3.8 

15.0 

.9 

2.3 

1.8 

2.6 

.5 

13.2 

.2 

.4 

.1 

.1 

0 

0

100.8

16

47.7 

11.5 

3.6 

3.5 

13.9 

.8 

1.3 

1.7 

2.9 

.5 

12.1 

.3 

.1 

.1 

.1 

0 

0

100.1

17

53.6 

10.0 

3.1 

3.3 

12.3 

1.5 

1.5 

1.3 

1.6 

.5 

10.8 

.2 

.4 

.1 

<-l 

0 

0

100.2

18

53.7 

11.1 

3.9 

3.2 

10.4 

1.3 

1.7 

3.1 

2.0 

.5 

9.0 

.2 

.3 

.1 

.1 

0 

0

100.6

1 Ferrous iron not determined because of the presence of organic matter.

13. Hill south of Alpine in the SWJiNE^ sec. 25, T. 4 S., R. 1 E.

14. Canal bank north of Dry Creek; SEJiSEJi sec. 27, T. 4 S., R. I E.

15. Lower part of formation in Dades Gulch; SEK sec. 34, T. 4 S., R. 1 E.

16. Upper part of formation in Dades Gulch; SEJ4 sec. 34, T. 4 S., R. 1 E.

17. Cave in railroad cut; SEJ^NWJi sec. 36, T. 4 S., R. 1 W.

18. Excavation for abutment for Jordan River bridge, Lehi-Cedar Fort road, 

also table showing traces of metals.

See
32 LAKE BONNEVILLE

TABLE 7.—Analyses of water-soluble salts in Alpine and Provo formations, in percent 

[Analyses by Margaret D. Foster, chemist, U. S. Geological Survey]

CaO— .... ————-...-...._..—.-.

MgO...... ................................

NazO.. ..-.-..-____..____..____.._______._

KsO........... _....._._.._.____.__._.__.._

COj..... ........... ........... ...........

80s-.— — — ... „—.-...._._._ .........

01......— ...............................

Total.. .............................

Provo formation

Northwest of Dry Creek

Near-shore 

deposits

1

0.01 

.02 

.63 

.04 

.14 

.25 

.77

1.86

2

0.01 

.01 

.17 

.03 

.25 

.04 

.01

0.52

3

0.01 

.01 

.05 

.03 

.17 

.08 

.01

0.36

Offshore deposits

4

0.01 

.01 

.30 

.01 

.24 

.25 

.18

1.00

5

0.17 

.03 

.58 

.03 

.11 

.72 

.38

2.02

6

0.01 

.01 

.49 

.04 

.13 

.26 

.36

1.30

7

0.05 

.03 

.37 

.02 

.13 

.21 

.67

1.48

Southeast of American Fork River

Onshore 

deposits

8

0.05 

.01 

.17 

.01 

.14 

.07 

.20

0.65

Near-shore 

deposits

9

0.01 

.02 

.28 

.01 

.25 

.01 

.01

0.59

Offshore 

deposits

10

0.06 

.06 

.04 

.03 

.32 

.01 

.01

0.53

11

0.01 

.04 

1.02 

.06 

.19 

.51 

.01

1.84

12

0.06 

.04 

.05 

.03 

.22 

.06 

.61

1.07

Alpine formation

Near-shore 

deposits

13

0.01 

.03 

.25 

.03 

.22 

.04 

.12

0.70

14

0.05 

.02 

.05 

.04 

.14 

.04 

.45

0.79

Offshore deposits

15

0.05 

.02 

.03 

.03 

.17 

.05 

.01

0.36

16

0.03 

.03 

.07 

.03 

.20 

.07 

.05

0.48

17

0.01 

.02 

.04 

.03 

.16 

.02 

.02

0.30

18

0.01 

.03 

.04 

.05 

.19 

.02 

.01

0.35

TABLE 8.—Analyses of water from Utah Lake 

[From Olarke, F. W., Data of geochemistry: U. 8. Oeol. Survey Bull. 695, p. 154,1920]

Cl——— ————— ———

S04— --------------

C03— _-__------_--_

LL_ _--_____-___.--_

Na-._

K.__. -___-_-_---.. -

Ca— ——— —— ———

Sr——— ——— _____„

Mg

SiO2— _--_--_-__-_-_

Total. __ _

Salinity, parts per 

million-.- ___.

A

4.04

42. 68

19.88

5. ol

18.24

6.08

3. 27

100. 00

306

B

35.48

26.53

2.66

26. 20

7.58

1.55

100. 00

892

C

26.23

28.49

10.23

/19. 28

\ 2. 34

6.25

7. 18

100. 00

1,281

D

24.75

28.25

12.35

.06

18. 19

9 17

5 Oft

. 15

6. 18

2.00

100. 00

1, 165

E

26. 87

30. 14

a

AO

18. 34

1 7f\

K OA

6.85

2.23

100. 00

1,254

A. By F. W. Clarke, U. 8. Geol. Survey Bull. 9,1884, p. 20.

B. By F. K. Cameron, 1899.

C. By B. E. Brown, 1903.

D. Mean of three analyses by A. Seidell, 1904. Samples taken in May.

E. By B. E. Brown, 1904. Collected August 31. For analyses B, C, D, and E, 

see F. K. Cameron, Jour. Am. Chem. Soc., vol. 27,1905, p. 113. All are here reduced 

to terms of normal carbonates.

COMPARISONS BETWEEN SIMILAR DEPOSITS FROM 

DIFFERENT SOURCES

In order to compare similar and contemporaneous 

lake deposits that seem to have had different sources, 

one set of samples was collected from near-shore and 

offshore silt and clay of the Provo formation lying north 

of Dry Creek, which contributed considerable granitic 

material to the lake, and another similar set was collected from the formation southeast of American Fork 

Kiver where the drainage tributary to the valley is 

almost entirely from limestone and quartzite. As 

shown in the following table these two parts of the 

Provo formation are very similar in composition.

The differences are surprisingly slight. It seems 

reasonable to infer that the rate of settling of sediment 

in the offshore and deep-water parts of the lake, during 

the Provo stage at least, was sufficiently slow to permit 

rather thorough mixing of those sediments across an 

area of at least 75 square miles on the lake bottom.

TABLE 9.—Proportions of certain constituents in the Provo formation in different parts of the valley

MgO_. ---.__--__-_____

CaO_— ---------------

Na2 0— ---------------

K2 0— ----------------

CO.— - — — . -------

P,0S—— ———— —————

SOs-- —— ——— ——— —

Cl_,—— _ — — _ ————

TotaL__-_----_--

Area northwest of Dry 

Creek

A

9.0 

40.5 

5.5 

5.3 

34.6 

.5 

1.8 

2.8

100.0

B

10.0 

43.3 

3.0 

6. 1 

35.7 

. 6 

1.0 

.3

100.0

Area southeast of American Fork River

C

9.5 

43. 1 

2. 2

4.7 

38.3

. 7 

.8

.7

100.0

D

9. 7 

44. 1 

1.4 

4.9 

38.3 

. 7 

. 6 

.3

100.0

A. Data from table 4 recalculated to 100 percent from the averages of 7 complete 

analyses of near-shore and offshore silt and clay deposits.

B. Data from table 4 recalculated to 100 percent on water-soluble-salt-free basis.

C. Data from table 5 recalculated to 100 percent from the averages of 4 complete 

analyses of near-shore and offshore silt and day deposits.

D. Data from table 5 recalculated to 100 percent on water-soluble-salt-free basis.

The two parts of the Provo formation also are similar 

with respect to the proportions of the various watersoluble salts, as shown in the following table.

TABLE 10.—Proportions of water-soluble salts in the Provo formation in different parts of the basin

MgO_---_- -------------------------

CaO ---- - - -

Na20. ------------------------------

KsO

C02 - ------------------------- -----

S03 - -------------------------------

Cl

Total..----------------------i

Average total content of the waterArea northwest of Dry 

Creek

A

2

3

29

3

21

17

25

100

1.22

Area southeast of American Fork 

River

B

5

5

28

3

31

10

18

100

0.94

A. Data from table 7 recalculated to 100 percent from the averages of 7 analyses of 

water-soluble salts.

B. Data from table 7 recalculated to 100 percent from the averages of 5 analyses of 

water-soluble salts.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 33

COMPARISONS BETWEEN SIMILAR DEPOSITS OF 

DIFFERENT AGE

Those facies of the Alpine and Provo formations 

that are composed chiefly of silt and clay and that seem 

to have had a common source are similar in composition, 

and especially so when allowance is made for their 

differing contents of water-soluble salts. This comparison is illustrated in the following table.

TABLE 11.—Proportions of certain constituents in lake-bottom deposits of parts of Provo and Alpine formations that had a common 

source

MgO__._______

CaO.._________

Na_0— _______

K_0--_-_-____.

CO_--_._______

P2 0S ___________

SO3— _---____.

CL—, ________

Total __

Provo formation northwest 

of Dry Creek

A

9.0 

40. 5 

5. 5 

5.3 

346 

.5 

1.8 

2.8

100.0

B

10.0 

43.3 

3.0 

6.1 

35.7 

.6 

1.0 

.3

100.0

Alpine formation along Dry 

Creek

C

11.4 

39.9 

3. 1 

5.4 

38. 1 

.8 

.3 

1.0

100.0

D

11. 1 

41. 8 

3.0 

5.4 

37.2 

.6 

.6 

.3

100.0

A. Data from table 4 recalculated to 100 percent from the averages of 7 complete

B. Data from table 4 recalculated to 100 percent on water-soluble-salt-free basis. 

C. Data from table 6 recalculated to 100 percent from the averages of 6 complete 

analyses. 

D. Data from table 6 recalculated to 100 percent on water-soluble-salt-free basis.

From these data it might be concluded that the environments under which the sediments of the two 

formations were derived and deposited were not 

sufficiently different to cause much difference in their 

chemical composition. With respect to water-soluble 

salts, however, the two formations are less alike, for 

the average salt content of the Alpine is less than half 

that of the Provo. The salt content of the two formations is inversely proportional to the volumes of water 

that were in the lake during the maxima of the two 

ttages, so probably the salt content of the water during 

she Provo stage was a few times greater than during 

the Alpine stage. However, the proportions of the 

different constitutents are somewhat different, as 

brought out in the following table.

TABLE 12.—Proportions of water-soluble salts in the Provo and 

Alpine formations

MgO—__ _......__-_.___........_..

CaO ____ .___ .

Na_O— ———___ — ________-____

K2 0— __ ___________________________

C02 _______________________________

80i-_ — _ — — ____-__ —— _ ________

CL ________________________________

Total. ___ _ _ _______ _ ___.

Average total content of the watersoluble salts (percent) _____ _ __ _

Provo 

formation

A

3

4

30

3

25

14

21

100

1. 10

Alpine 

formation

B

6

5

15

8

41

9

16

100

0.49

Probably the most striking difference in the proportions of the various salts in the two formations is 

the ratio of Na2O to K2O, which averages about 2 to 

1 in the Alpine and about 10 to 1 in the Provo. The 

ratio is about 10 to 1 in the Utah Lake waters also. 

(See table 8.)

The salt content of the Alpine formation is more like 

that part of the Provo formation southeast of American 

Fork than like the Provo northwest of Dry Creek, despite the fact that the Alpine formation samples were 

taken from along Dry Creek. Perhaps the Alpine formation in that part of the area is composed dominantly 

of sediments derived from American Fork River. Perhaps also the sediments from different sources were less 

well mixed in the Alpine formation than in the Provo 

formation.

COMPARISONS BETWEEN NEAR-SHORE AND OFFSHORE 

DEPOSITS

Additional differences between the Alpine and Provo 

formations appear by comparing the compositions of 

the near-shore and offshore deposits of silt and clay. 

The distribution of water-soluble salts with respect to 

proximity to the old shores is exactly opposite in the 

two formations.

In the Alpine formation the total of the water-soluble salts increases shoreward; the salt content of the 

Provo formation decreases shoreward, as shown in the 

following tables:

TABLE 13.—Distribution of water-soluble salts in samples from 

silt and clay facies of the Alpine formation

[Proportion of certain constituents to total water-soluble salts (percent). Data from

table 7]

MgO ——— ————— ————

CaO— —————-.——— NaaO———— ——— —— ——— K2O— —— ——— —— —— —

COi.— -————-— — —

SO3— — ———————

01...—————————————

Total.—————————.

Total content of water-soluble

Near-shore 

deposits

13

4 

1 

36 

4 

32 

6 

17

100

0.70

14

3

6 

6 

5 

IS 

5 

57

100

0.79

Offshore 

deposits

15

6 

14

8 

8 

47 

14 

3

100

0.36

16

6 

6 

15 

6 

42 

15 

10

100

0.48

Deep-water 

deposits

17

7 

3 

13 

10 

53 

7 

7

100

0.30

18

9 

3 

11 

14 

54 

6 

3

100

0.35

Average

6 

5 

15 

8 

41 

9 16

100

0.49

TABLE 14.—Distribution of water-soluble salts in samples from

silt and clay facies of the Provo formation 

[Proportion of certain constituents to total water-soluble salts (percent)] 

Sediments from area northwest of Dry Creek

A. Data from table 7 recalculated to 100 percent from the averages of 12 analyses 

of water-soluble salts in near-shore and offshore silt and clay deposits. 

B. Data from table 7 recalculated to 100 percent from the averages of 6 analyses.

MgO————— —— ——— — CaO—— —— — — — — ——

NsaO........... ..............

KtO..—— — — — — — ——

CO.——— — ————— —— —

803 ...... ....................

Cl__..——— —— ——— —— —

Total. _ .. _ —— . ..

Total content of water-soluNear-shore 

deposits

1

1

34 

2 

8 

13 

41

99

1.86

2

<2 

<2 

33 

6 

48 

8 

<2

100

0.52

3

<3 

<3 

14 

9 

47 

<3 

22

100

0.36

Deep-water deposits

4

1 

1 

30 

1 

24 

25 

18

100

1.00

5

<1

9 

29 

1 

6 

36 

19

100

2.02

6

<1 

<1

38 

3 

10 

20 

28

100

1.30

7

2 

<3 

29

<l 

14 

46

100

1.48

Average

9 

3 

29 

3 

21 

17 

25

100 

1.22
34 LAKE BONNEVILLE

TABLE 14.—Distribution of water-soluble salts in samples from 

silt and clay fades of the Provo formation—Continued

Sediments from area southeast of American Fork River

MgO.—— ..................

CaO—~ — ..— — -— — .

NajO... ..... .............. .

KsO-_. .................. ..

COi. .......................

SOs— ------------------

Cl.... ....-. — -.-.-.. ......

Total............ ......

Total content of waterOnshore 

deposits

8

2 

7 

26 

2 

22 

11 

30

100

0.65

Offshore 

deposits

9

4 

<2 

47 

<2 

42 

<2 

<2

100

0.59

Deep-water deposits

10

11 

11 

8 

6 

60 

2 

2

100

0.53

11

2

1 

55(?) 

3 

10 

28 

1

100

1.84

12

4 

6 

5 

3 

20 

6 

56

100

1.07

Average

5 

5 

28 

3 

31 

10 

18

100

0.94

TABLE 15.—Traces of heavy metals in Provo and Alpine formations 

(in parts per million)

[Semiquantitative colorometric tests by Lyman Huff and Hy Almond, 

U. S. Geological Survey]

Also brought out by these data is the fact that in the 

Alpine formation the proportion of chlorides to total 

salts- is greatest in the near-shore deposits; least in the 

deep-water deposits. The proportion of carbonate is 

greatest in the deep-water and least in the nearshoredeposits. Sulfate forms the greatest proportion of the 

total in an intermediate zone. As can be seen from the 

tables the proportions of these cations in the Provo is 

quite different from those in the Alpine.

The distribution of salts in the Alpine formation is 

suggestive of the conditions recorded at Sevier Lake 

(Gilbert, 1890, p. 226) where sulfate is deposited in the 

middle of the basin while chloride is deposited chiefly 

at the margin.

UTAH LAKE

Table 8 gives some analyses of the water of Utah 

Lake that were made between 1883 and 1904. Clarke 

(1924, p. 159) states that in the 20-year period represented by the samples the lake "has undergone a 

thorough transformation, and its salinity has more than 

quadrupled. From fresh water of the sulfate type it 

has become distinctly saline * * *." This change is 

attributed to artificial changes in the water supply, 

control of discharge from the lake, and irrigation.

Comparing the salt content of Utah Lake since 1900 

with that of the Provo formation it should be noted 

that in each case the calcium-magnesium ratio is about 

1:1 and the sodium-potassium ratio is about 10:1. The 

proportions of sulfate, chloride, and carbonate, however, are reversed. In Utah Lake SOg^Cl^COs; in 

the Provo formation C03>C1>S03 .

TRACES OF HEAVY METALS

Traces of heavy metals in the lake deposits were 

determined approximately by colorometric tests using 

dithizone. The results are given in table 15.

The sediments sampled were derived from American 

Fork River canyon. The tests suggest that the maximum concentration of heavy metals is in the fineTotal heavy metals 1 

Zn__. ____________

Pb

Onshore 

deposit

A

100 

80 

25

Near-shore deposit

B

25 

35

Not run

c

25 

35 

5

Offshore deposit

D

85 

55 

10

E

90 

80 

15

F

90 

60 

10

o

100 

80 

20

1 As a result of heavy-metals tests.

A. Gravel and silt, Provo formation; grab sample from wall of aqueduct in the 

NE}4sec. 36, T. 4 S., R. IE.

B. Clean gravel, Provo formation; grab sample gravel pit in the NW}4 sec. 18, 

T. 58., R. 2 E.

C. Clean sand; same locality as B.

D. Clay, Provo formation; NEJ-4 sec. 22, T. 5 S., R. 1 E. Grab sample about 

6 inches below surface.

E. Clay, Provo formation, SEJ4 sec. 20, T. 5 S., R. 1 E. Grab sample about 12 

inches below surface.

F. Clay, Provo formation, from excavation for bridge abutment. NW}4 sec. 13, 

T. 5S., R. 1 W.

G. Clay, Alpine formation; same locality as F.

grained sediments and that the proportion of zinc to 

lead, which averages about 5:1, is fairly constant between the coarse- and the fine-textured facies.

SALINITY OF LAKE BONNEVILLE

Almost certainly Lake Bonneville became increasingly saline as its waters diminished in volume, but 

the problem of changes in salinity is complicated by 

the fact that shrinkage of the lake waters was due only 

partly to dessication. The fall of the lake from the 

Bonneville stage to the Provo stage, for example, 

apparently was due to overflow and must have occurred quickly. The salinity at these two stages, 

therefore, probably was about the same. The available data still are not sufficiently complete to reconstruct that part of the geologic history represented by 

the break between the Alpine and the younger formations in the Lake Bonneville group. After the Provo 

stage the lake level fell very gradually by dessication, 

and the salinity of the lake waters must have increased 

rather steadily. Even this phase of the problem, 

however, is complicated by the fact that Utah Valley 

was a bay that almost, if not altogether, closed as the 

lake receded from the Provo to the Stansbury level. 

Moreover, after Lake Bonneville shrank to the Stansbury level, Utah Valley drained into Salt Lake Valley 

by way of Jordan River and this change must have 

caused Utah Lake to become less saline.

We can be reasonably sure that the salt content of 

the Lake Bonneville waters in the bay represented by 

Utah Valley was well below the saturation point for 

quiet cool water because no beds of saline precipitates 

occur in the offshore deposits. During the Bonneville 

and Provo stages calcium carbonate was precipitated 

in some nearshore deposits at headlands, but this 

precipitation seems to have resulted from very local
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 35

conditions that were not generally prevalent, perhaps 

because of aeration by surf action or perhaps because 

of biochemical action.

Part of the salts that occur in the offshore deposits 

of the Lake Bonneville group may have resulted from 

reactions between the silt and clay particles with the 

saline solution through which they settled. A considerable part, however, must have been contained in the 

water that saturated the layers of mud on the lake 

bottom; when the lake waters receded from such a 

layer there would be left a mud containing saline water 

whose salts would be precipitated as the mud became 

dry.

The high-level and near-shore deposits in the Alpine 

formation, where this condition most likely prevailed, 

contain 0.75 percent water-soluble salts. The salinity 

of the water during the Alpine stage, therefore, may 

have been of the order of several thousand parts per 

million.

The beds of the Alpine formation in the interior of 

the valley on the other hand contain as little as 0.3 

percent water-soluble salts but these beds represent 

muds that were compacted by burial under other lake 

bottom sediments. They would have lost much of 

their water and its contained salt before final drying. 

Such reasoning contains many uncertainties but the 

probabilities seem to favor the higher rather than the 

lower figure as approximating the salinity of the lake 

at that stage.

Those deposits of the Provo formation that were 

nearest shore and first exposed as the lake shrank from 

the Provo level average about 0.75 percent watersoluble salts. Probably, therefore, at the beginning 

of the Provo stage, and probably also during the preceding Bonneville stage, the salinity was not greatly 

different from when the Alpine formation was deposited. 

But the deposits farthest from shore, which remained 

under water until the lake had shrunk (by dessication) 

practically to the level of Utah Lake, average almost 

1.5 percent of water-soluble salts. This would suggest that the salinity doubled during the Provo stage, 

and may have been many thousands of parts per 

million.

Utah Lake now has a salinity of only a thousand or so 

parts per million, presumably a result of the freshening 

effect caused by Jordan River draining from the lake.

CALCIUM CARBONATE DEPOSITS

The rocks in the mountains from which the sediments 

in Utah Valley were derived include considerable 

limestone. As would be expected, therefore, the 

valley's sediments are highly calcareous. The lime 

carbonate is finely distributed throughout all the

247743—53———4

formations in the valley regardless of their texture, 

origin, or age. In addition, calcium carbonate has 

become concentrated locally at many places in the 

valley. These local concentrations are of at least 

four kinds, but the criteria for distinguishing them are 

not clear.

One kind seems to be related to surf action in Lake 

Bonneville. Gilbert (1890, pp. 167-169) described 

this kind and indicated its origin as follows:

The distribution of the tufa along each shore is independent 

of the nature of the subjacent terrane. The heaviest observed 

deposits are upon quartzite and granite at a considerable distance from calcareous rocks. The most conspicuous accumulations are upon rock in place, but this difference probably depends 

upon the fact that deposits upon unconsolidated material are 

largely interstitial. A more important peculiarity of the 

distribution is its relation to wave action. No deposit is found 

in sheltered bays; and on the open coast those points least 

protected from the fury of the waves seem to have received the 

most generous coating. These characters indicate, first, that 

the material did not have a local origin at the shore but was 

derived from the normal lake-water; second, that the surf 

afforded a determining condition of deposition.

Some of the most firmly cemented calcium carbonate 

deposits in Utah Valley are at places that were headlands in Lake Bonneville and perhaps these deposits 

were conditioned by surf action. Some examples are 

the deposits in the spits at the Point of the Mountain, 

both in the Provo and Bonneville formations, and a 

similar deposit in the Bonneville formation at the 

southernmost point of the Traverse Mountains in 

sec. 30, T. 4 S., R. 1 E.

A second kind of deposit is illustrated by the calcium 

carbonate in the upper part of the gravel facies in the 

Highland bench and Orem bench deltas. This carbonate is concentrated in a zone comprising the upper few 

feet of the gravel, generally in the topset beds, but these 

gravels are not firmly cemented. Commonly overlying 

the lime-rich zone is a foot or so of eolian(?) brown 

silt. (See p. 22.)

The lime carbonate in these gravel deposits probably 

was formed about the time the deltas were constructed. 

When the lake shore stood at the front edge of these 

deltas the ground-water level must have been only a 

few feet below their subaerial surfaces. The upper 

few feet of the gravel, therefore, would be subject 

alternately to wetting and drying, and would become 

the site for precipitation of calcium carbonate from 

the ground waters.

Still a third kind of calcium carbonate deposit is the 

result of spring action and occurs in part as true tufa. 

These deposits have been observed at several localities: 

in the alluvial deposits in a small southern tributary 

of Dry Creek at the front of the Wasatch Range; along 

the contact between the glacial outwash and the
36 LAKE BONNEVILLE

fanglomerate of the pre-Lake Bonneville deposits just 

south of Dry Creek in the SEtf sec. 12, T. 4 S., R. 1 E.; 

in fanglomerate of pre-Lake Bonneville deposits at the 

south point of the Traverse Mountains in sees. 31 and 

32, T. 4 S., R. 1 E.; and along the front of the Wasatch 

Range just below the Bonneville level about 2 miles 

north of Pleasant Grove. The calcium carbonate 

deposit at the south point of the Traverse Mountains 

firmly cements angular gravel and occurs in steeply 

dipping banded veins of calcite. The other deposits 

are more or less horizontally layered tufa.

A fourth kind of lime carbonate concentration is 

attributable to soil processes, by which the upper 

layers of the soil become leached and the lime becomes 

deposited in the underlying layers. Throughout the 

area, in the Lake Bonneville group and younger formations, calcium carbonate has been leached from the 

upper few inches and redeposited in a zone several 

inches thick beneath the leached zone. The uppermost 2 or 3 inches of the leached zone does not effervesce 

in cold dilute hydrochloric acid; the materials below 

effervesce strongly. In the silty and clayey formations 

the redeposited lime takes the form of tiny white specks 

or veinlets that minutely mottle the brown soil. The 

mottled layer commonly is 10 or 12 inches thick. In 

gravelly formations the lime tends to form a coating 

on the pebbles. On pre-Lake Bonneville deposits 

locally there are remnants of an ancient and more 

maturely developed soil in which the lime-enriched 

zone may be as thick as 20 feet and locally buried under 

10 feet of leached clay. (See p. 43.) These calcium 

carbonate deposits are the result of soil-forming 

processes.

Criteria for distinguishing the four forms of calcium 

carbonate deposits are not very satisfactory. The 

layered deposits of tufa and the banding in the calcite 

veins are distinctive, but related spring deposits that 

impregnate clastic sediments would be difficult to recognize unless perhaps it could be established that these 

lime deposits contain diagnostic traces of metals or 

other elements. The lime carbonate in the deposits 

attributed to surf action at headlands is more firmly 

cemented and more spottily distributed than is the 

carbonate attributed to a formerly high ground-water 

table. The lime concentrated in the substrata of ancient 

soils commonly is associated with distinctive concentrations of reddish-brown clay (p. 43). Feeble development below a very shallow leached layer is the most 

distinctive feature of the lime concentrated by postPro vo soil processes. Possibly there are geochemical 

and minerological differences between these different 

kinds of lime deposits that could be developed as criteria for distinguishing them, but this phase of the 

problem was not studied.

COMPARATIVE VOLUMES OF THE FORMATIONS

The formations in northern Utah Valley differ in 

thickness and extent and obviously differ in volume. 

Estimating the volume of the different formations 

requires numerous assumptions, some of which are of 

doubtful validity, but the effort is probably of some 

value in that it reveals differences in the order of 

magnitude of erosion in the highlands that each valley 

formation represents.

Besides assuming the correctness of the correlations 

and positions of contacts as given in the description 

of the individual formations it is necessary to assume:

1. That the sediment in northern Utah Valley represents all the sediment derived from the drainage basins 

of the streams tributary to that part of the valley, 

and that it does not include material transported by 

streams tributary to the south half of the valley. 

Making this assumption probably involves no great 

error.

2. That half the Salt Lake formation is indigenous 

and reworked pyroclastic material and that the other 

half represents bedrock erosion during the volcanic 

cycle. This assumes that the pyroclastic facies of the 

formation were derived equally from all parts of the 

entire drainage basin, including the valley itself, and 

that the other half which represents erosion of bedrock 

was derived equally from all parts of the drainage basins 

tributary to the valley. The error introduced by this 

assumption probably is small compared to the error of 

assuming a thickness for the formation.

3. That the Pleistocene pre-Lake Bonneville deposits 

and the post-Provo alluvial deposits were derived 

equally from all parts of the stream basins tributary 

to the valley. No doubt the greater altitude of the 

Wasatch as compared to the other mountains was 

reflected hi greater precipitation and denudation there, 

but the error is believed to be small compared to the 

error of assuming an average thickness for these 

deposits.

4. That Lake Bonneville group was derived very 

largely from the Wasatch Range and that the increment 

of sediment from the other and lower ranges during 

the lake period was comparatively little. The distribution and kinds of materials found in the lake 

deposits indicate that this assumption introduces no 

great error.

5. That a cubic foot of the valley deposits equals 

0.8 cubic foot of consolidated rock in the mountains.

Provo River drains an area of about 650 square miles 

and apparently has drained that area since earliest 

Pleistocene time because chips of lava and purple 

quartzite, apparently derived from the headwaters, 

were identified in the cuttings from a well at the 

Geneva Steel plant down to a depth of at least 600 feet.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 37

American Fork River drains about 60 square miles, 

while Dry Creek and its tributaries above Alpine drain 

about 22 square miles. The totalarea in the Wasatch 

Range and mountainous areas farther east that is 

tributary to northern Utah Valley is only a little greater 

than this total of 730 square miles. About 10 square 

miles of the Traverse Mountains drain into Utah 

Valley. About 25 square miles of the Lake Mountains 

and other lower hills west of Utah Valley have contributed materially to sedimentation in northern Utah 

Valley. Northern Utah Valley itself comprises 1.75 

square miles.

Assuming the Salt Lake formation to have an average thickness of 500 feet under the valley, its volume 

would be about 17.5 cubic miles. Half of this has been 

assumed to be derived from bedrock erosion in the areas 

tributary to the valley and represents erosion of 7 cubic 

miles of rock from an area of 745 square miles, or an 

average lowering of the whole tributary highland surface by about 48 feet. The other half of the Salt Lake 

formation, the pyroclastic fades, is assumed to include 

some pyroclastics deposited directly in the valley, the 

rest washed in from the highlands. The total volume 

of this unconsolidated material is about 8.75 cubic 

miles, which represents a layer of pyroclastics roughly 

50 feet thick spread over an area of 920 square miles.

If the pre-Lake Bonneville Pleistocene deposits 

under the valley average 500 feet in thickness, their 

volume also is about 17.5 cubic miles. This represents 

14 cubic miles of bedrock removed from an area of 

about 745 square miles, or an average denudation 

amounting to roughly 95 feet of bedrock.

If the Alpine formation averages 75 feet in thickness 

under the valley, its volume is about 2.6 cubic miles. 

This has been assumed to have come largely from the 

Wasatch Range and represents an average lowering of 

the bedrock surface there of about 14 feet.

The volume of the Bonneville formation is negligible.

The Provo formation aggregates about 0.5 cubic 

mile if its average thickness is 15 feet. This formation 

represents the removal of about 3 feet of bedrock from 

the whole surface of the tributary part of the Wasatch 

Range.

Post-Provo deposits probably aggregate only a 

tenth as much volume as the Provo formation and, 

therefore, represent the erosion of only a few inches of 

bedrock material from the whole surface of the adjoining highlands.

These estimates are more easily compared if 

tabulated.

Comparative volumes of the formations in northern Utah Valley 

and the depth of bedrock erosion represented by them

Formation

Post-Provo formations. .... . ...........

Lake Bonneville group:

Salt Lake formation (for eacb 500 feet of thickness and excluding indigenous and reworked

Total....——————————————

Estimated volume of material 

eroded from the 

bedrock of the 

adjoining highlands (in cubic 

miles)

(')

0.5

(1) „

2.6

3.1

14.0

7.0

24.1

Average amount 

of lowering of 

the whole surface 

of the adjoining 

highlands 

(in feet)

0)

3

(0

14

17

95

48

160

i Negligible.

DEPTH OF VALLEY PELL

Very likely there is considerable relief on the bedrock surface under the valley fill and total depth of the 

fill probably varies considerably from place to place.

The summits of several buried hills of Paleozoic rocks 

protrude through the fill near the foot of the Lake 

Mountains. Paleozoic rocks also are exposed at 

several places below the Bonneville level at the foot of 

the Wasatch Range and in some gullies in the f anglomerate south of the Traverse Mountains in the SEK 

sec. 30, T. 4 S., R. 1 E. Volcanic breccia, no doubt 

Tertiary and perhaps older than the Salt Lake formation, is exposed in the SWJi sec. 2, T. 5 S., R. 1 W. 

These exposures are too incomplete to suggest the pattern that might be expected in the old topography 

buried under the interior of the valley.

The deepest boring in the valley, the well drilled 

by the Geneva Steel Co. in the SEtfNWtf sec. 8, T. 

6 S., R. 2 E. (A-16225), is 830 feet deep and the base of 

the Pleistocene assuredly is no higher than 500 feet 

below the surface there (fig. 5). The deep well at 

Cutler may have penetrated into the Salt Lake formation but none of the wells has reached Paleozoic 

formations.

In March 1947 the Geological Survey's airborne 

magnetometer was flown along seven east-west traverses 

that crossed the valley in Tps. 5 and 6 S. and along a 

diagonal traverse roughly following the D., R. G., & 

W. R. R. from Provo across the Jordan Narrows. A 

magnetic anomaly was detected at the Jordan Narrows but no anomalies were found in the interior oi the 

valley. This indicates that there are no buried hills 

containing volcanic rocks like those in the Traverse
38 LAKE BONNEVILLE

Mountains within a few -thousand feet of the surface 

of northern Utah Valley.

The fact that the Pleistocene deposits in the valley 

appear to thicken southward suggests that in general 

the depth of the valley fill increases in that direction.

STRUCTURAL GEOLOGY

Utah Valley is a structural valley bounded by late 

Tertiary and Quaternary faults; the valley undoubtedly is primarily the result of faulting, although folding 

or tilting may have contributed to the displacement.

The late Tertiary and Quaternary faults all appear 

to be normal faults. Those along the east side of the 

valley occur in a complex zone along the front of the 

Wasatch Range, but A. A. Baker, who has been studying and mapping that part of the Wasatch, has found 

parallel faults apparently belonging to the same system 

deep within the mountains also. The faults shown 

along the front of the Wasatch Range (see pi. 1) 

therefore represent only the westernmost of a wide set 

of faults which have had late Tertiary and Quaternary 

displacement. Very probably similar faults break the 

bedrock beneath Utah Valley.

The faulting that gave rise to Utah Valley probably 

began prior to deposition of the Salt Lake formation 

and has continued intermittently practically to the 

present time. This late Tertiary and Quaternary 

faulting belongs to the epoch of block faulting that 

affected the Basin and Range province generally. 

Wholly different and seemingly independent of this 

orogeny is the earlier so-called Laramide thrusting and 

folding that is so evident in the Wasatch and in the 

mountains of the Basin and Range province. Structural movements attributed to the Laramide orogeny 

seem to have occurred during most of Cretaceous and 

early Tertiary time. (Spieker, 1946.)

There is no single Wasatch fault. There is, rather, a 

wide complex fault zone in which the greatest displacements seem to be in that part of the zone bordering 

the mountain front. In this part of the zone most of 

the disturbed strata are down-dropped to the west 

along the faults; a few faults are down-dropped on the 

east side.

Paleozoic rocks are displaced many thousands of 

feet along these faults. The aggregate displacement 

on all the faults across the fault zone in front of the 

mountains probably is as great as the present topographic relief and may exceed it. In front of Mount 

Timpanogo the total displacement is probably 7,000 

feet or more. Two miles north of Pleasant Grove a 

block of Manning Canyon shale has been faulted 

down about 4,000 feet.

Along several faults at the mountain front pre-Lake 

Bonneville Pleistocene deposits are displaced a few

hundred .feet. Along the same faults Paleozoic rocks 

are displaced many hundreds or a few thousands of 

feet. The Manning Canyon shale, for example, is 

displaced 4,000 feet along one of the faults north of 

Pleasant Grove but along the same fault, pre-Lake 

Bonneville Pleistocene deposits are displaced only 

about 450 feet.

The Lake Bonneville group is faulted too. At the 

mouth of American Fork Canyon the Bonneville 

formation is displaced about 60 feet. About one-half 

mile up Provo Canyon other gravel deposits of the 

Lake Bonneville group also are displaced a few tens 

of feet.

The older of the two moraines just above the town 

of Alpine is displaced about 100 feet along a fault; 

southward, at Boxelder Creek, the fault dies out and 

the displacement evidently is taken up by tilting of 

the Boxelder Creek fan. This fan consequently has a 

steeper surface than do neighboring fans and the creek 

has incised a deep gorge in it. The fault reappears in 

the Pleistocene deposits between Boxelder Creek and 

American Fork Canyon.

The fault pattern along the west and north sides of 

the valley may be similar to that along the front of 

the Wasatch. Pre-Lake Bonneville Pleistocene deposits are faulted but the mapping of the bedrock faults 

is incomplete. On the east end of the Traverse Mountains fanglomerate of pre-Lake Bonneville deposits, 

has been raised a few hundred feet, almost certainly 

because of faulting, and has been deeply dissected.

The late Tertiary Salt Lake formation is involved in 

faulting and is tilted about 45° where it is exposed in 

the Jordan Narrows. It is likely that Utah Valley 

had already started to develop when this formation 

was deposited (p. 12).

The evidence in Utah Valley harmonizes with that 

from other parts of the Basin and Range province and 

indicates that the many thousands of feet of block 

faulting that produced the valley was the result of 

repeated small movements over a very long period of 

time. The movements probably began in middle or 

late Tertiary time and have continued intermittently 

practically to the present. Indeed, because the Wasatch 

front is the center for repeated mild seismic disturbances it is even possible that the mountain blocks 

are rising today as vigorously and violently as they 

ever have in the past. Ten thousand feet of displacement can form a high mountain but if that movement 

is distributed through a few million years only inches of 

displacement are required during so brief a period as 

the Christian era. Actually 60 feet of movement is 

known to have occurred since Lake Bonneville time.

The fact that the Bonneville formation at one place 

has been raised above its shoreline indicates that
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 39

during the most recent movement the mountains were 

the active block; the mountains were raised, the valley 

lagged behind. Perhaps the valley was raised also, 

though less so than the mountains. Probably during 

the earlier movements too the valley block has been 

more passive than the mountains.

Gilbert (1890, pp. 365-373) has pointed out that the 

Lake Bonneville group has been slightly warped. 

According to his data Utah Valley has been tilted 

slightly southeastward.

Well data (p. 14) indicate that the formations comprising the valley fill in Utah Valley thicken southeastward and probably the bedrock surface is deeper 

at the south than at the north. These data, combined 

with those gathered by Gilbert, suggest that the southeastward tilting of Utah Valley, like the faulting, has 

progressed intermittently since the valley was formed.

Except for this warping or tilting, evidence of structural movements within the valley is generally lacking. 

The Provo formation covers most of the valley and it 

has not been observedly faulted or tilted. Numerous 

small faults break the foreset beds in the deltas but 

the displacement is measurable only in inches and generally is down toward the delta front. Almost certainly these breaks reflect settling rather than structural 

movements. An interesting feature of these breaks is 

the fact that they sharply separate the displaced beds 

even though they are unconsolidated; there is essentially 

no drag. Along the shore of Utah Lake, west of the 

Geneva Steel plant, the nearly horizontal Provo formation lies with angular unconformity on steeply tilted 

beds belonging to the Alpine formation. These beds 

of the Alpine formation commonly dip 30°-40° E., and 

in places they are severely contorted in small recumbent 

folds. The discordance is considerable and very likely 

reflects sublacustrine slippage rather than structural 

deformation, for contorted bedding is a rather common 

feature in the Alpine formation.

When a considerable part of the Lake Bonneville 

basin has been remapped precise levels correlated with 

the geological studies no doubt will reveal much information about recent diastrophic movements in the 

region. The valley still is mildly active seismically. 

(See p. 60.) How much warping can the bedrock and 

overlying unconsolidated deposits endure before they 

yield, by slipping again, and break? Neither seismologists nor geologists know the answer, but precise 

knowledge of the geological record and precise knowledge of minute changes in level that may be taking 

place today are certainly minimum essentials for 

determining that answer.

GEOLOGICAL HISTORY

ORIGIN AND STRUCTURAL HISTORY OF THE VALLEY

As to the origin of Utah Valley we have few facts. 

Probably the valley is due very largely to block faulting, 

by which the adjoining mountain blocks have been 

raised relative to the valley block. But it should be 

noted that geologists are unable to evaluate the degree 

to which folding or tilting of the blocks has contributed 

to or otherwise influenced the deformation.

The block faulting that formed Utah Valley and other 

valleys in the Basin and Range province has continued 

to the present time and the faulting may be continuing 

today as vigorously as in the past. Certainly there are 

many very recent fault scarps in the Province and many 

parts of it are seismically active. Utah Valley is no 

exception. The block faulting is known to have 

progressed intermittently at least since Pliocene time. 

How much earlier it started is not yet known.

Presumably the folding and thrust faulting of the 

Paleozoic and Mesozoic rocks in the mountains adjoining Utah Valley occurred during late Mesozoic and 

earliest Cenozoic time, as it did farther south in central 

Utah (Spieker, 1946, pp. 149-155). The block faulting 

by which the valley assumed the shape and proportions 

we see today occurred later and was superimposed on 

the older structures. However, until regional geological 

mapping is more complete than it is today, we have 

no way of determining to what extent the older structures have controlled the younger ones.

Gilluly (1932, pp. 40, 65-66, 85-86) has reasoned 

that the volcanism in the area immediately northwrest of Utah Valley is late Eocene or Oligocene. 

These lavas have been deformed and it seems likely 

that their deformation was related to the deformation 

that developed Utah Valley, though the principal 

structural movements may have come later and may 

have differed somewhat in type from the earlier movements. For the present, little more can be done than 

to assume middle Tertiary time as the date when Utah 

Valley began to develop as a structural valley. By 

late Tertiary time it seems to have become a valley 

of appreciable size because the valley sides were 

sufficiently high and steep to supply boulder conglomerates to the Salt Lake formation. By early 

Pleistocene time the valley had developed proportions 

such as we see today.

Although the early history of the block faulting is 

obscure the later history is clear. The facts that the 

Paleozoic rocks are more deformed than the late 

Tertiary Salt Lake formation, that the Salt Lake 

formation is more faulted and tilted than the pre-
40 LAKE BONNEVILLE

Lake Bonneville Pleistocene deposits; and that the 

pre-Lake Bonneville deposits are more faulted than the 

Lake Bonneville group clearly indicate that the fault 

movements that produced the valley have progressed 

intermittently during a long period of time.

In most regions the geologic record of mountainmaking movements is even less complete than in 

Utah Valley. Can we be sure that the more ancient 

diastrophic changes elsewhere were, on the average, 

any more vigorous or violent than in this valley? 

If the geologic record back to the beginning of Paleozoic time were as complete as the Pleistocene record in 

Utah Valley we might find that the earth has been 

undergoing virtually continual deformation since the 

beginning, that mountain-making movements in different parts of the world have so overlapped as to span 

all the elapsed time, and that the strains in one part of 

the crust became relieved and movement ceased as new 

strains and new movements developed elsewhere. 

Continued and unbroken sedimentation in the interior 

of a geosyncline remote from the mountains that were 

being eroded to furnish the sediments is not evidence 

that there was a lack of repeated movements in those 

mountains. On the contrary, the very constancy of 

the supply of sediments, both as to volume and kind 

that characterize so many of the ancient geosynclines, 

strongly suggests that their source mountains were not 

catastrophically raised and then eroded to mere stubs, 

but that the mountains were being raised all the while 

they were furnishing sediment to the geosyncline, in 

the same way that the growing Wasatch Range 

furnished sediments to Utah Valley during Pleistocene 

time.

HISTORY OP SEDIMENTATION IN THE VALLEY

In late Tertiary time there accumulated in the 

valley a considerable thickness of well-stratified volcanic debris (Salt Lake formation), evidently deposited 

in part in quiet water probably under lake or playa 

conditions. Some of these water-laid beds are tuffs 

that represent ash falls for they contain abundant, 

well-preserved, fragile glass shards. With these are 

beds that seem to be largely reworked ash, probably 

material washed into the late Tertiary playa or lake 

from the pyroclastic deposits that fell on the adjoining 

highlands. Conglomerates representing erosion of the 

lavas and other bedrock formations in the adjoining 

highlands are interstratified with the tuffs and reworked 

ash.

The extent of the old lake in which these sediments 

were deposited is not known, but because the block 

faulting which formed the valley probably was already 

well advanced it seems likely that the late Tertiary 

lakes or playas corresponded roughly to the present

valley areas. Absence of any traces of lacustrine* 

features (shore-lines) above the Bonneville formation 

shore-line is indicative that none of the earlier lakes 

exceeded Lake Bonneville in size, particularly because 

the mountain blocks have been rising progressively.

About the time that the volcanism waned the late 

Tertiary lake disappeared or at least greatly diminished 

in size. The history of sedimentation during pre-Lake 

Bonneville Pleistocene time still is fragmentary but 

apparently it includes periods when huge alluvial fans 

were constructed far into the interior of the valley, 

separated by at least three periods when lakes, presumably glacial lakes like Lake Bonneville, were 

created. (See fig. 5.) The fanglomerate that was 

deposited immediately preceding Lake Bonneville is 

like that being deposited today and very likely represents mudflows and other flood deposits that accumulated under topographic and climatic conditions 

similar to those of today.

About 17.5 cubic miles of sediment are included in 

these pre-Lake Bonneville Pleistocene deposits, which 

is equivalent to an average lowering of roughly 95 feet 

in the adjacent mountains which were the source of 

the sediments (p. 37).

The Pleistocene was concluded by the epoch of Lake 

Bonneville and the latest glaciation, presumably 

equivalent to the Wisconsin. During the earliest stage 

of Lake Bonneville vast quantities of fine-grained 

sediments (Alpine formation) were deposited in the 

lake. The Alpine formation has a volume of about 2.6 

cubic miles (p. 37), and probably more than half of 

this material is silt size or finer. Its volume and proportion of fines exceed that of any of the later deposits. 

This large volume of material represents an average of 

about 14 feet of erosion from the entire surface of the 

tributary highlands, but the sediment could have 

been deposited rather quickly if, as seems likely, it 

represents accelerated erosion of a deep soil rather than 

direct erosion of the bedrock itself.

This first advance of Lake Bonneville seems to have 

preceded, somewhat, the glacial maximum represented 

by the younger of the moraines at the mouth of Alpine 

Canyon; outwash from that moraine overlies the Alpine 

formation but gravel deposits interbedded with the 

finer-grained sediments of the Alpine probably represent 

glacial outwash that formed during the advance of the 

glacier.

Gilbert (1890, pp. 141-146, 260) has presented evidence to show that during this first stage of Lake 

Bonneville the lake surface oscillated and the stage 

was followed by dessication. In Utah Valley no evidence 

was found to demonstrate that the lake surface oscillated, while the Alpine formation was being deposited, 

but there is evidence that the formation was exposed
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 41

and eroded before the Provo formation was deposited. 

The Provo formation overlaps the eroded edges of the 

Alpine formation and in places rests on pre-Alpine 

deposits suggesting that the Alpine had been removed 

be erosion. Moreover, at many places in the valley 

there is a striking disconformity between the contorted beds of the Alpine formation and the overlying 

undisturbed beds of the Provo formation.

Lake Bonneville rose to its maximum height when the 

Bonneville formation was deposited. In Utah Valley 

only gravelly littoral deposits have been recognized as 

belonging to this stage and their volume is insignificant 

in comparison with that of the Alpine. The stage 

seems to have been short-lived.

Above the town of Alpine the Bonneville formation 

is composed very largely of granitic boulders and 

pebbles derived from the outwash from the younger of 

the moraines at the mouth of Alpine Canyon.

When the highest stage was attained Lake Bonneville 

overflowed into the Snake River valley by way of Red 

Rock Pass (Gilbert, 1890, p. 260) and the lake level 

fell rapidly to the level of the Provo stage—in Utah 

Valley about 300 feet lower than the Bonneville level.

At the Provo stage large deltas were built in the lake 

at the mouths of the principal streams draining the 

Wasatch Range. During this stage the lake currents 

moved northward along the front of the Wasatch 

Range, for the deltas have a sand facies northwest of 

a medial gravel facies, and sand, and gravel bars off the 

front of the deltas were built northwestward.

The Provo formation has a volume of about half a 

cubic mile, of which probably less than a fourth is silt 

size or finer. The proportion of coarse and fine-textured 

material transported into the lake during the Provo 

stage is rather like that being brought in today and is 

quite unlike that brought in during the earliest stage 

when the Alpine formation was deposited. The texture 

of the Provo formation suggests that the extent of 

soil cover in the mountains at that time was only a 

little greater than at the present time. The volume of 

the Provo formation represents only a few feet of lowering of the surface of the adjoining highlands.

After the Provo stage the lake fell gradually to the 

level of Utah Lake. Detailed study of the succession 

of bars (or beaches) that lie in front of the deltas no 

doubt would furnish considerable information regarding 

the fall of the lake from the Provo level, for the bars 

appear to have formed during this period. Since then 

only minor fluctuations of level have been recognized. 

The Stansbury stage (Gilbert,, 1890, p. 134), which 

roughly conforms to the level of Utah Lake, has not 

been recognized in Utah Valley.

Since Provo time most of the valley has been subject 

to fluviatile sedimentation and erosion. The principal

streams have cut channels across the old deltas and 

have built broad low fans on the plain formed by the 

lake-bottom sediments in front of the deltas. Along 

the fronts of the mountains the old alluvial fans are 

again being enlarged as boulders and finer sediment are 

being washed onto their surfaces. But the total volume of material brought into the valley since Provo 

time is only one-tenth the volume of the Provo formation.

The differences in texture and form of the several 

Pleistocene deposits in Utah Valley appear to be related 

only remotely if at all to the succession of structural 

movements that occurred while the deposits were 

forming. Instead, as outlined in the following section 

of this report, the differences resulted primarily from 

variations in the climate.

BONNEVHJLE— A WISCONSIN LAKE

That the older of the moraines in Alpine Canyon is 

pre- Wisconsin is indicated by the thick layer of clay 

on its surface which is the result of residual weathering 

of the deposit. This ancient soil is assuredly a preWisconsin phenomenon (Hunt and Sokoloff, 1950), 

like the gumbotil in the Middle West (Kay, 1916, 

pp. 637-638). It is described more fully on page 43. 

The younger moraine lacks this soil and evidently is 

one of the Wisconsin moraines.

Interstratified with the Alpine formation along Dry 

Creek are beds of granitic gravel that evidently represent glacial outwash. The youngest bed is at the base 

of the Provo. The meltwaters that produced these 

deposits probably discharged into the lake at least 

seasonally even during the time when the glaciers were 

forming and advancing.

Although the last definite evidence of glacial meltwaters is the gravel bed underlying the Provo formation 

in the upper part of Dry Creek, very probably the 

Provo formation itself was supplied by meltwaters 

during the waning stages of the glaciation. There is 

no other apparent source for the volume of water and 

sediment represented by the Provo stage.

Gilbert (1890, pp. 309-310), and later Atwood 

(1909, pp. 92-93) and Antevs (1925, pp. 74-77) agreed 

that the maximum of the last glaciation (Wisconsin) 

in the Wasatch Range occurred before the Provo stage 

but probably immediately following the Bonneville 

stage of the lake. The stratigraphic evidence provided 

by the deposits in northern Utah Valley is consistent 

with this general interpretation. Still to be explained, 

however, is the significance of the unconformity between the Alpine and the younger formations of the 

Lake Bonneville group, which implies that the lake 

twice reached high level stages in Wisconsin time.
42 LAKE BONNEVILLE

EVOLUTION OF THE CLIMATE, TOPOGRAPHY AND SOILS

At the close of Tertiary time the relief of the Utah 

Valley region must have been nearly as great as it is 

now. Since the close of Tertiary time the valley floor 

has been built up by 500 feet of sediments, and at the 

same time erosion has lowered the mountains an average 

of about 160 feet. Only if Quaternary faulting exceeded about 660 feet, could relief at the close of 

Tertiary time have been less than it is now. In all 

probability Quaternary faulting did exceed this but 

only by hundreds (rather than thousands) of feet. 

Nevertheless, during Quaternary time, the landforms 

and the extent and kind of soil cover must have undergone a succession of major changes because of variations 

in the climate.

During at least part of late Tertiary time there 

appear to have been lakes in which the volcanic ash 

beds were deposited. At that time therefore the precipitation-evaporation ratio was greater than at present.

At the beginning of Pleistocene time conditions 

changed. Fanglomerates, like those being deposited 

today, were washed into the valley and very likely the 

climate, topography, and soils were similar to those of 

the present time. We may infer that when these earliest 

fanglomerates were forming, the mountains were practically as high and as rocky and craggy as they are 

today, the climate probably was semiarid, and the soil 

forming processes probably were as feeble as they are 

today.

This semiarid period, however, seems to have ended 

by a shift to more humid conditions that led to the 

forming of the first of the Pleistocene lakes. While 

the climate was more humid the soil-forming processes 

must have been more vigorous, and the rocks in the 

mountains may have become cloaked in deep soil that 

softened the mountain landforms. Very likely too, the 

first Pleistocene glaciation in the mountains occurred 

during or immediately following this stage.

Well records in the valley indicate that a cyclic 

change from semiarid to humid conditions occurred at 

least three times in the Pleistocene prior to Lake 

Bonneville, which was the last of the great Pleistocene 

lakes.

An increase in the precipitation-evaporation ratio is 

recorded by the rise of Lake Bonneville during the 

Alpine ("Intermediate") stage. The lake level appears 

to have fallen by desiccation after the Alpine formation 

was deposited. This suggested aridity may be more 

apparent than real, because about this time one of 

the sets of Wisconsin glaciers formed on the mountains. 

Their melting and the return of apparently more humid 

conditions caused the lake to rise to the Bonneville 

level. This climate probably continued almost to the 

close of the Provo stage. From then on the precipitation-evaporation ratio decreased, evaporation became 

excessive, and the lake level fell.

The distribution and changes in facies of the Lake 

Bonneville group show that along the east side of Utah 

Valley the shore currents of the lake were northerly, 

certainly so during the Provo stage, and probably also 

during the Bonneville and Alpine stages. This would 

indicate that during the existence of Lake Bonneville 

the prevailing winds came from the southwest. This 

contrasts with the record of the last 20 years or more 

during which the prevailing winds have come from the 

north and northwest.

Some ancient and deep soils on the mountains 

apparently record stages when the climates were humid. 

At the time these soils were formed weathering conditions were favorable for developing smoothly rounded 

slopes on what had been rocky and craggy surfaces. 

Remnants of the smoothly rounded landforms are 

still preserved in parts of the Wasatch Range and 

conspicuously so in the Traverse Mountains. These 

landforms, the product of past humid climates, are 

strikingly different from the rugged shapes that are 

being carved by the processes of the present semiarid 

climate.

Remnants of the ancient deep soils are still preserved at places on the bedrock, on the pre-Lake 

Bonneville fanglomerates, and on the older of the 

Alpine Canyon moraines. At several places the old 

soils are overlapped by the Lake Bonneville group. 

It is likely that this deep soil mantling the mountains 

furnished the fine-grained sediments of the Alpine 

formation. By Bonneville and Provo time however 

much of the old soil had been stripped away and the 

streams again began eroding on bedrock, for those 

formations are composed largely of coarse detritus.

Since Provo time the climate has become semiarid. 

Mountains are being carved into rocky landforms 

characteristic of such a climate, and the modern soils 

are only feebly developed. Under the present climate 

practically no soil is being formed on rock surfaces, 

as erosion today is vastly more effective than weathering

The fall of the lake to the level of Utah Lake permitted Dry Creek, American Fork River, and Provo 

River to cut deep channels in the unconsolidated 

deposits of the deltas; the materials eroded from these 

channels were deposited in broad low fans where the 

streams issued from the deltas onto the pro-delta silts 

and clays. The fans at the foot of the mountains 

have again started to grow and by the same processes 

that built the older and vastly larger parts of those fans.

The several great Pleistocene lakes that have existed 

in Utah Valley very likely correlate with the major 

glacial periods that have been recognized in other 

parts of the world. Substages in the glacial and inter-
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 43

glacial periods no doubt are also recorded in the sedimentary record and very likely will be revealed rather 

fully when surveys in the Bonneville and Lahontan 

Basins have been completed. These basins appear to 

offer an unusually fine opportunity for reconstructing 

the climatic record of Pleistocene time.

AN ESTIMATE OF THE GEOLOGIC TIME AND RATE OF 

EROSION REPRESENTED BY THE FORMATIONS

Despite grave uncertainties in the available information it is interesting to try to estimate the duration of 

some of the stages in the Pleistocene history of Utah 

Valley and the magnitude of the variations in rates of 

erosion and sedimentation that must have occurred. 

In a first approach to the problem an average rate of 

erosion is assumed in order to estimate the time; in a 

second approach the time is assumed in order to estimate differences in the rates of erosion.

The volume of post-Provo deposits in northern Utah 

Valley is of the order of one-quarter billion cubic yards, 

or about 0.05 cubic miles. Post-Wisconsin time has 

generally been estimated to comprise 20,000 to 25,000 

years but recent radiocarbon tests suggest that the 

duration may be as little as 10,000 years. The radiocarbon evidence is forceful but still to be proved valid, 

so for present purposes we will assume a compromise 

figure of 15,000 years.

The Lake Bonneville group, representing the Wisconsin deposits in Utah Valley, aggregates 3.1 cubic 

miles and at the post-Provo rate of sedimentation 

this would have required 60 times the length of postProvo time or about 900,000 years. This figure is ten 

to fifteen times greater than the estimates generally 

given for Wisconsin time. If the generally given 

estimates are correct, it would appear that, in Utah 

Valley, the rate of erosion during Wisconsin time was 

ten to fifteen times faster than it has been since.

In another approach to the problem it will be assumed first that the duration of the Provo stage exactly 

equalled the duration of the Alpine stage. These two 

formations were derived under quite different conditions. The Provo consists of 0.5 cubic miles which is 

mostly gravel and sand whereas the Alpine consists of 

2.6 cubic miles which is mostly silt and clay. If the 

two stages were equal in duration the rate of erosion 

during Alpine time was five times as fast as during 

Provo time. If the Provo formation accumulated at 

the same rate as did the post-Provo deposits, which 

also are coarse elastics, the Provo required 150,000 

years. The Alpine and Provo together thus would require 300,000 years. Even this estimate is three to 

five times greater than the estimates usually given for 

Wisconsin time.

Crude as these estimates are, they do indicate either 

that Wisconsin time was of greater duration than has 

commonly been supposed, or that erosion and sedimentation were at much faster rates than during the postProvo epoch. Both may be true.

Also it might be noted that the volume of the Wisconsin deposits, the Lake Bonneville group, is about 

18 percent of the total volume of the Pleistocene deposits in the valley. Wisconsin time may constitute 

about 18 percent of those stages of the Pleistocene that 

are represented by vigorous erosion in the mountains. 

But intervening between those stages of erosion were 

stages when weathering exceeded erosion, stages when 

deep residual soils developed in the mountains and, 

seemingly, very little sediment was removed to the 

valley.

It seems likely therefore that Wisconsin time represents something less, probably considerably less, than 

18 percent of all of Pleistocene time.

RELATION OF THE GEOLOGY TO SOME SOIL 

PROBLEMS

ANCIENT SOILS

Some ancient and deep soils that were formed in 

pre-Lake Bonneville time have been found in Utah 

Valley. These soils were formed originally by the processes that operated under climates that antedated the 

lakes and glaciers.

The ancient soils are restricted to the pre-Lake Bonneville deposits, and are further restricted to those 

areas on those deposits where the surface has been preserved through the Lake Bonneville and post-Lake 

Bonneville time. These conditions are found at numerous places above the high-water mark of Lake Bonneville along the foot of the Wasatch, Traverse, and 

Lake Mountains. Old soils are extensive on the preLake Bonneville fanglomerate, on the older of the 

moraines above the town of Alpine, and on the Paleozoic 

and other bedrock formations. In the development of 

the ancient soils, a product was created wholly different 

from the original parent material.

The ancient soils consist of an upper layer that is 

lime-free and clayey and a lower layer that is composed of lime-enriched, weathered parent material.

The upper layer, which locally is as deep as 10 feet, 

is deep reddish brown, granular, and very sticky loam 

or clay. Downward it becomes lighter-colored and 

more yellowish brown. It contains few pebbles and 

locally is entirely free of pebbles. Most of the pebbles that remain in this layer are quartzite; at places, 

however, other materials can be recognized but these 

generally occur as deeply decayed, soft relic pebbles or 

cobbles.
44 LAKE BONNBVILLE

Both lime and clay have been concentrated in the 

lower layer of the ancient soils. This clay commonly 

is in the upper part of the principal lime-enriched zone. 

It is very light colored. Some of it is lime-free but 

most of it is limey; part of this lime is finely mixed 

through the clay and part is in a fretwork of tiny veinlets. At some places the clay occurs as a distinct 

layer, at other places it forms lenticular masses, and 

locally it is 2 X feet thick. The concentration of lime, 

however, extends down many more feet. This lime 

impregnates the weathered parent material, coats pebbles, and forms a network of veins and veinlets that 

branch downward, evidently the product of downwardpercolating waters. This lime-enriched layer in places 

is 20 feet thick.

These soils were formed from a variety of parent 

materials: granitic moraine; fanglomerate composed of 

quartzite, limestone, and latitic lavas; Paleozoic shale; 

and Paleozoic limestone. The soils that formed from 

granitic or quartzitic parent materials have conthe topography. Since the soils were formed the valleys have become deeper and the hillsides steepened. 

The streams have cut through the upper clayey layer 

and into the lime-rich layer, and in places have cut into 

the weathered parent material. At other places 

hillside wash has buried the ancient soil under more 

recent material.

Where pre-Lake Bonneville fanglomerate has been 

elevated and dissected, as for example northwest of 

Alpine, gullies have cut through the upper clayey layer 

and into the lower lime-enriched layers. On some of 

the fans in front of the mountains the old soils are 

concordant with the present surfaces of the fans, but 

locally the soils are buried beneath younger gravel. 

It would be expected, therefore, that the clay layer of 

the ancient soils would be thinned irregularly by erosion 

and would be modified by the addition of lime derived 

from the younger wash on the surface of the ancient 

soil. These general relations are illustrated 

diagrammatically in figure 10.

Post

Lake Bonn

!"IGUBE 10.—Diagrammatic section to illustrate some relationships between the geology and soil development in northern Utah Valley. An ancient and deep soil in the preTrfllrfi Rnnnp.villA alluvial cra^pl is fficnrirffanf- fr.n frhA nrASAnfr tnrinoranVnr anrl ic n*7wlair» HIT- T.alrii "RnnnATTiltft frrnnn anrl nn«f-.T.alr<s Rnnrnvcrillo alln-trial ora-trial A nnst-T.fllrA

siderable sand in the upper clayey layer. Approximately 65 percent of this clay can be washed through a 

325-mesh sieve. Only small amounts of calcium 

carbonate occur in the lime-enriched layer of soils 

on nonlimey parent materials. The soils that formed 

from Paleozoic limestone or shale, or fanglomerate 

derived from them, have a highly clayey upper layer 

above a thick and strongly lime-enriched layer containing weathered fragments of the parent material. 

More than 90 percent of the clay layer in soils that 

formed from shale formations can be washed through a 

325-mesh sieve.

The considerable depth of these ancient soils is the 

more impressive because of the fact that many of 

the localities are on moderately steep hillsides where 

runoff and surface wash would be favored.

These soils are overlapped by the Lake Bonneville 

group. Their occurrence today is restricted to those 

pre-Lake Bonneville surfaces that have been preserved. 

Today the ancient surfaces are being dissected, and the 

profiles of the ancient soils now are discordant with

Soils like these are not found on the Lake Bonneville 

group and younger deposits. On the Lake Bonneville 

group and younger deposits the soil profiles generally 

are only 1 or 2 feet deep, except very locally where 

there has been a concentration of surface water. The 

depth of a soil profile is largely controlled by the depth 

to which surface water percolates; in the ancient soils 

water must have pentrated to depths as great as 30 

feet. The depth of the ancient soils commonly is 

10 to 15 times the depth of the whole profile of the 

modern soils. It is evident that the ancient soils must 

be the product of a past climate or climates wholly 

unlike the semiarid present.

Still unanswered is the question of the degree to which 

the ancient soils represent a complex of profiles superimposed on one another. Ancient soils like these provide fine evidence of past climatic changes, as pointed 

out by Bryan and Albritton (1943, pp. 469-490), and 

may prove to be a valuable tool for correlating Pleistocene events in provinces where the sedimentary record 

is lacking.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 45

MODERN SOILS

The soil profiles in the Lake Bonneville group and 

younger deposits are feebly developed and the texture 

and composition of the parent material still dominates 

those soil profiles. This is rather clearly shown by the 

close similarity between the geological map of Utah 

Valley and the reconnaissance soil map made in 1903 

by Sanchez (1904). Moreover, the modern soils are 

shallow; they rarely are more than a very few feet deep.

Although most of the soils on the Lake Bonneville 

group and younger deposits involve only minor alteration of the parent material, there nevertheless must be 

significant soil differences between some localities that 

involve similar parent materials. For example, the 

sand and gravel bars in front of the Highland bench delta 

have the same composition as the sand and gravel on 

the deltas, and the internal structure of the two is 

alike. But on the deltas the sand and gravel is underlain by many feet of like material—all of it permeable; 

whereas at the bars the sand and gravel is underlain 

by comparatively impermeable silt at a depth of only 

a few feet. On this silt is perched considerable ground 

water. The soil process obviously changes at the 

perched water table and in addition the soil climate 

in the sand and gravel above this water table must be 

very different from the soil climate of the sand and 

gravel in the deltas.

Other differences in the substrata of other deposits 

undoubtedly also affect the soil climate and also the 

plant and (or) animal life of their soils. The silt 

member of the Provo formation, for example, generally 

overlies silt or clay of the Alpine formation, but at a 

few places, notably at Pleasant Grove and locally along 

the west side of the valley, silt belonging to the Provo 

formation overlaps highly permeable pre-Lake Bonneville fanglomerate.

Variations in surface drainage conditions in different 

areas on a single parent material likewise introduce 

variations in the kind of soil developed on that material. 

West of the Geneva Steel plant, for example, the clay 

member of the Provo formation has evidently been 

subjected to repeated flooding from the marshy ground 

that formerly existed at the site of the steel plant's 

reservoir. This clay has at the top a distinct leached 

zone overlying a distinct lime-enriched zone; the profile 

extends to a depth of a few feet. Along the bluffs of the 

Jordan River, however, the same clay has only the 

feeblest sort of soil profile and this to a depth measurable 

only in inches.

SALINE SOILS

Soil processes change the content, kind, and distribution of soluble salts in or on the ground. On the 

other hand geologic processes control the content, kind,

and distribution of soluble salts in the undisturbed 

parent material.

Some of the orderly variations in the salt content of 

the Provo and Alpine formations which appear to have 

been controlled by the conditions of sedimentation 

when those lake beds were deposited have been pointed 

out elsewhere in this report (pp. 31-35). The distribution of salts in those lake beds is orderly and the 

distribution pattern is a factor that must be considered 

in appraising either the degree or the means by which 

the soil processes have changed or redistributed the 

salts. In brief, the "alkali" problem cannot be understood and overcome until there has been ascertained 

the source of the salts that are found in or on a given 

piece of ground. At some localities lands may have 

been damaged because of salts introduced by irrigation 

waters; at other localities equal damage may result 

from only slight movement and/ (or) slight reconstitution of the salts left in the ground by earlier geologic 

processes. Solving the problem requires distinguishing 

these two very different conditions.

PLEISTOCENE HISTORY AS A FACTOR IN SOIL GENESIS

Pleistocene geological history is a vitally important 

factor in soil genesis and in some aspects of the problems 

of soil classification. Probably on every part of the 

earth and certainly in the temperate zones the present 

climate is quite unlike the climates of the past, so in 

order to understand the origin and to properly classify 

a soil at a particular place it is essential to know to 

what extent the soil is the product of climatic conditions 

that no longer prevail. In the same way, the plant 

and animal life that have lived on and in the soil have 

changed and at some places even the topographic 

position has changed. Only the parent material remains constant during the development of a particular 

soil, and in a strict sense even this can be thought of as 

varying to the degree that the other changes may cause 

a new soil profile to be superimposed upon some part 

or all of an older one. In considering the origin and 

some aspects of the classification of soils, the geological 

history of the soil is unimportant only where the soil is 

so recent that it is entirely the product of present-day 

processes.

Soils like the ancient soils in Utah Valley are not 

found on the Lake Bonneville group or younger deposits. 

Since Lake Bonneville time the climate has been arid 

or semiarid and the soil-forming processes have been 

feeble. Soil profiles on the Lake Bonneville group and 

younger deposits rarely are more than 2 or 3 feet deep 

except where there has been a concentration of surface 

water simulating more humid conditions. It cannot be 

assumed that the differences between the pre-Lake 

Bonneville and the younger soils are due primarily to
46 LAKE BONNEVILLE

the difference in the length of time available for the 

two kinds of soils to form, because the ancient soils 

formed under conditions wholly unlike the present. 

It is even possible that the ancient soils formed in less 

time than did the modern ones.

The depth of a soil profile is very largely controlled 

by the depth to which water penetrates, and under the 

present climate water penetration is very shallow 

except at especially favored localities. The ancient 

soils are 10 to 15 times as deep as the modern soils. 

Regardless of the time factor, therefore, the modern 

climate could not develop soils as deep as the ancient 

ones.

Time probably has been overemphasized as a factor 

in soil genesis. Time of course is important but chiefly 

because the passing of considerable time witnesses 

major changes in the other factors—especially the 

climate and organisms—that are more fundamental to 

the process. Many thousands of years, for example, 

have elapsed since Provo time, yet the climate and 

organisms have been such that only very feeble soil 

profiles have formed during those thousands of years; 

the profiles still are dominated by the kind of parent 

material on which they formed. On the other hand, it 

is quite possible that much briefer periods of time during the past, when the climate was different, would 

suffice to impose strong soil profiles whose upper layers 

in no way resemble the parent material.

Time alone would appear to affect the degree, 

rather than the kind, of alteration that results in soil. 

Given sufficient time, however, a soil will reach equilibrium with the environment in which it is forming; 

it will become mature. But the length of time required for soils to attain equilibrium varies with the 

kind of environment. In this sense, the feebly developed modern soil profiles may be fully as mature as 

the strongly developed ancient ones.

Similarly, the topographic position of a locality— 

that is, its slope and exposure—on which soil forms, 

in general affects the degree rather than the kind of 

alteration that results in soil. The ancient soils in 

Utah Valley are very much alike regardless of their 

topographic setting, and the modern soils that developed on one kind of parent material are much alike 

regardless of their topographic setting. More important to soil development than either time or topographic position are the factors of climate, parent 

material, and organisms.

Probably equally important to the factors of time and 

topography is a factor that has not been emphasized 

sufficiently—geologic environment, especially the stratigraphy and geologic structure in and around a 

particular soil. The importance of this factor to soil 

development in Utah Valley is illustrated by the

several varieties of the modern soils that are due to 

differences in the kind of deposit that lies below the 

parent material. The kind of subsoil significantly 

affects the moisture and other soil-climate conditions 

in the overlying soil. Drainage generally is recognized 

as highly important in soil development, but drainage 

is conditioned mostly by geologic environment, namely 

the permeability of the underlying materials, which 

is determined by the stratigraphy, and the depth to the 

saturated zone, which is commonly a function of the 

regional geomorphology and geologic structure.

Five factors generally are cited as controlling soil 

development. These are climate, parent material, 

topography, organisms, and time. To these should be 

added the sixth factor, geologic environment; and 

distinction should be made between those factors that 

primarily control differences in kind of weathering 

and those that primarily control differences in degree of 

weathering. Furthermore it should be emplasized 

that each of the factors is in itself a variable depending 

on geologic history. The six factors might be organized 

and phrased as follows:

Factors that primarily control difference in kind of weathering:

1. The kind of climate or succession of climates under 

which a soil material formed.

2. The kind or kinds of parent material from which a soil 

was derived.

3. The plant and animal life, past and present, that have

lived on and in a soil.

Factors that primarily control differences in degree of 

weathering:

4. The topographic position, past and present, of the 

locality.

5. The geologic environment, past and present, of the 

locality.

6. The length of time that each condition in each of the 

other five factors has been operative.

SOME GEOLOGICAL ASPECTS OF EROSION AND 

FLOOD CONTROL PROBLEMS

The streams that normally bring much needed water 

to Utah Valley occasionally reach flood stages and 

bring destruction. When they are in flood, they erode 

land under cultivation or along roadbeds or elsewhere, 

by flowing outside of the normal channels. In addition, they deposit debris where it is unwanted. Considerable work has been undertaken in order to give 

protection against such damage. Much of this effort 

is obviously of only temporary value, perhaps mada 

during a flood, for the protection of a specific structure 

or tract of land. More and more people have realized 

that such stopgap measures are inadequate, and that 

watersheds must be managed on the basis of comprehensive and long-range planning, if the water crop 

produced by them is to give maximum benefit and 

minimum damage.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 47

The effectiveness of land management depends upon 

the understanding and proper evaluation of the natural 

processes and forces involved. The geologic factors 

are important among those that need to be understood 

and evaluated.

For appraising the geological aspects of erosion and 

floods in Utah Valley the geologic history can be divided 

into three main periods represented by the pre-Lake 

Bonneville deposits and soils, Lake Bonneville deposits, 

and post-Provo deposits and soils.

The only strongly developed and deep soils in Utah 

Valley are those ancient clayey ones that were formed 

prior to the period of Lake Bonneville. Soils that are 

post-Provo in age are only feebly developed and are 

shallow as compared to older soils. The ancient soils 

are erosion remnants or have become buried by younger 

deposits; in either case they face extinction. In the 

strictest sense of the word they are an irreplaceable 

resource. We cannot hope to stop completely the 

removal or burial of these ancient soils but we can hope 

to avoid wasting them.

The largest part of the ancient soils apparently was 

eroded from the uplands during the early stages of 

Lake Bonneville when the Alpine formation was 

deposited. Most of the 2.6 cubic miles of that formation apparently represents erosion of the deep clayey 

soil that had formed extensively in the mountains, and 

the volume represents an average 15-foot lowering of 

the whole surface of the adjoining highlands (p. 37), an 

amount that is entirely consistent with the known 

depths of the ancient soils. The quantity of ancient 

soil remaining around Utah Valley is only a trifling 

fraction of the original; the quantity eroded since man 

reached the area is negligible as compared to the 

quantity that was eroded before he arrived.

Under the present climate the forces of erosion are 

vastly more powerful than are the forces of weathering. 

A climate that impresses such feeble soil profiles on the 

unconsolidated deposits in the valley could hardly be 

expected to develop soil on firm rock; this is reflected 

in the high proportion of boulders, pebbles, and smaller 

rock fragments now being transported into the valley 

by streams eroding the highlands. It is very unlikely 

that the unconsolidated deposits and soils that remain 

in the highlands are being replenished. They face 

removal as surely as do the ancient soils preserved 

around the edges of the valley. Under the present 

climate the mountains seem to be destined to become 

more rugged and rocky.

During parts of pre-Lake Bonneville time also the 

forces of erosion evidently exceeded the forces of 

weathering and soil formation. The debris eroded 

from the highlands during those periods and accumulated as fanglomerate, in all respects resembles that

being brought into the valley today. During that time 

the Wasatch and other ranges must indeed have been 

bare and craggy. Many cubic miles of rock debris 

were eroded from the highlands during the semiarid 

periods that preceded Lake Bonneville (p. 37).

The post-Provo deposits aggregate about 0.05 cubic 

mile, or about 250,000,000 cubic yards. If post-Provo 

time totals 15,000 years the average annual quantity 

of debris washed into the valley would be about 15,000 

cubic yards. At this average rate 1,500,000 cubic 

yards would have been washed into the valley during 

the 100 years of occupancy by white man. Precise 

measurements are lacking and the figures cited have 

little quantitative value, but it is exceedingly doubtful 

if the rate of influx of rock and debris since man's 

arrival significantly differs from the average that prevailed during the several thousand years preceding 

1850.

As long as the present climate continues there will 

be continued erosion in the mountains, continued floods 

into the valley, and continued feebleness of soil development—for these are the results of such a climatic 

pattern upon this area. Thus the soils on the uplands 

bordering Utah Valley are an irreplaceable resource. 

Protection of vegetative cover, check dams, and other 

expedients are designed to minimize the destructive 

effects of these natural forces. But they do not modify 

the climatic, geologic, or physiographic factors that 

are the major causes of floods and erosion. Many 

efforts to date have been expedients that do not guarantee security against disaster, and they should not be 

judged harshly when they fail. Much more research 

on the powerful natural forces involved is needed, in 

order to find means of supplementing and working with 

those forces, rather than against them.

ENGINEERING GEOLOGY

By HELEN D. VARNES

The geology of Utah Valley is directly related to the 

wide variety of uses to which the natural materials are 

or can be put. Each geologic unit, by reasons of its 

composition and the method by which it was formed, 

has distinctive sets of properties that determine the 

extent and limitations of its possible uses.

The geological study of the valley enables one to 

obtain an over-all picture of the engineering properties 

of the various materials—a picture useful in the early 

stages of planning for large-scale construction such as 

new road alinements, canals, or industrial buildings. 

Adequate data on the kind and distribution of the 

earth materials that make up Utah Valley facilitate 

location of construction materials such as gravel, sand, 

and riprap, and can also be used in making preliminary 

estimates on excavation and fill requirements. Sub-
LAKE BONNEVILLE

sidence of foundations and roads, excessive leakage in 

irrigation ditches, and similar problems are directly 

tied to the geologic environment; hence knowledge of 

the geology affords an explanation of the source of these 

troubles in already-existing structures and makes it 

possible to foresee and prevent them in new construction.

The manner in which materials are used largely 

determines which of their properties are significant. 

For this reason, this discussion of the engineering 

properties of the formations in Utah Valley is divided 

into three sections: foundation materials; construction 

materials unprocessed except by screening or washing; 

and construction materials that are processed in some 

manner, such as the burning of clay for brick or tile, 

or the dressing of building stone.

On the Engineering Geology map (pi. 2) the deposits 

are separated into map units based primarily on the

posed and a symbol given to indicate the relative position of each. For example, a deposit of river gravel 

overlain by 10 feet or less of silt has the silt-clay and 

the gravel patterns superimposed with the symbol

Si-Cl

-zsr to indicate that the silt-clay deposit overlies the

river gravel.

Where the same material persists to depths greater 

than 10 feet, or where possible superposition of materials 

at less than 10 feet could not be detected, only the pattern and symbol for the surficial material are shown. 

It is probable that many more areas than are shown on 

the present map should be patterned to represent 

changes in materials at shallow depths. A complete 

and accurate determination of such relationships 

throughout the valley would require an extensive 

program of trenching and deep auger holes that was

Poorly developed gravelly soil

Mostly coarse, poorly - sorted gravel

O ° ° <-, 0 o o

-Offshore

25 Feet

FIGURE 11.—Cross section showing characteristic bedding in a delta front. Horizontal, poorly sorted topset beds overlie sloping, well-sorted foreset beds. Exposure is of 

gravel member of the Provo formation in the Johnson gravel pit (center of the N^NWH sec. 18, T. 5 8., R. 2 E.).

kind of material predominating in each deposit, such as 

gravel, sand, mixed sand and gravel, and so on. The 

kinds of material and their attendant properties are 

governed largely by mode of deposition and parent 

materials; for engineering purposes the chronology of 

the deposits is not important.

The depth to which a specific material extends is as 

important as its areal extent in the consideration of 

foundation conditions or in estimating available reserves 

of construction materials. An attempt has been made, 

therefore, wherever sufficient information was available, 

to indicate vertical as well as lateral differences in 

composition.

Wherever the thickness of one material overlying 

another material was known to be 10 feet or less, the 

patterns representing the two materials are superimnot possible within the scope of the present study. 

Ten feet was chosen as the critical point principally 

because information to determine superposition of 

materials at a greater depth could not be obtained for 

large enough areas.

Still another aspect of the geology that concerns 

engineering problems is the seismic activity along the 

front of the Wasatch Range. A brief summary of the 

known seismic history is included in this chapter.

FOUNDATION MATERIALS

Foundation materials in Utah Valley serve to support 

such structures as buildings, roads, bridges, canals, and 

small check dams. Their usefulness can best be judged 

by examining the properties that affect foundation and 

excavation conditions. The more important properties
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH

are drainage and permeability, stability and shearing 

strength, and workability. As these properties of the 

various geologic units can be consistently compared on 

the basis of general field examinations and available 

service records, they seem to offer the best basis for 

discussion of the Utah Valley materials.

BENCH GRAVEL

The principal deposits of bench gravel (gravelsized material is greater than 2 millimeters hi diameter) 

comprise the deltas (fig. 11) built into Lake Bonneville 

by Dry Creek, American Fork and Provo Rivers, 

and also comprise the great spits at the Point-of-theMountain. In addition there are some small lake 

terrace deposits. Most of these bench gravels are composed of moderately well graded to poorly graded,

s.

surface. In this area excavations deeper than about 

10 feet may encounter appreciable quantities of water,

Stability.—The lime-cemented zones in the bench 

gravels have moderate to high strength depending on 

their content of cement. Uncemented deposits have 

low internal friction when dry and without support are 

unstable in high-angle cuts. In general the gravels are 

good foundation material with little tendency to settle.

Workability.—The gravel can be excavated easily 

although the strongly cemented zones locally may 

require blasting.

RIVER GRAVEL

The river gravel deposits are largely confined to the 

channels and flood plains of Provo River, American 

Fork River, and Dry Creek, the principal streams

Poorly developed 

gravelly soil

O 0 000 0 OOOQ0 0o0000 OO

o o o_^ o o . 0 - •» ° ° °

000° 00° 00

o o 0 

° ° 0 „ o „ o o o

100 Feet

FIGURE 12.—Cross section of post-Provo river-laid gravel deposits at American Fork. Qravelpit in the 8WH8EH sec. 13, T. 5 S., R. 1 E.

rounded pebbles with a low percentage of fines, usually 

much less than 30 percent. On the map (pi. 2) they 

are shown as bench gravels (GrO.

Permeability and drainage.—The bench gravels are 

highly permeable. Water losses in them would be 

considerable, and water-control structures require 

lining. Most of the delta gravels, however, are more 

or less impregnated by lime cement (calcium carbonate) 

which partly coats the pebbles and reduces the porosity 

of the mass. Generally the cement is most strongly 

developed near the tops of the deposits, but locally it 

impregnates a zone as deep as 12 feet; permeability in 

such places is low. The lime-cemented zone, however, 

is seldom so tight that it interferes completely with 

ground drainage. Because the bench gravels lie considerably above the permanent ground-water table, 

excavations will generally be well-drained to depths of 

a few tens of feet. The area between Dry Creek and 

Mitchells Hollow may be an exception, for a perched 

water table lies on an impervious bed of clay of the 

Alpine formation, which apparently has a very irregular

draining into northern Utah Valley. On the map 

(pi. 2) they are shown as River gravels, gr2 . Riverlaid gravels characteristically vary widely in grading 

and texture because the capacity of rivers to carry and 

deposit material varies seasonally as well as at different 

stages of a single flood. A rude lateral variation in 

the deposits is generally found, however. Where the 

rivers leave the mountains, grading is very poor and 

the material includes boulders a foot or more in diameter. Fines of sand size or smaller are often negligible 

hi amount and localized in occurrence. Tile average 

size of the gravel decreases downstream, the percentage 

of fines increases, and the deposits are generally well 

graded.

The gravel pit in the American Fork River flood 

plain (SWtfSEtf sec. 13, T. 5 S., R. 1 E.) is typical of 

the river gravels deposited a few miles from the mountain front. Most of the coarse material ranges from 

y\ to 2 inches in diameter. These gravel beds, however, 

are lenticular and in most places interstrattfied with 

irregular beds of fine sand, silt, and clay (fig. 12).
50 LAKE BONNEVILLE

Permeability and drainage.—Permeability of the river 

gravels, like tlie bench gravels, is generally high. The 

river gravels are largely free of lime cement, although 

there is a notable exception in the vicinity of Alpine 

where the flood-plain deposits along Dry Creek apparently include deposits that are older than most of the 

other exposed river gravels. The percentages of fines 

mixed with the river gravels is considerably greater than 

in the bench gravel deposits but probably does not 

greatly reduce the porosity. Silt and clay lenses are 

interbedded with the gravel and impede drainage 

locally; they can be expected to occur with increasing 

frequency and thickness toward the mouths of the 

rivers. Water-control structures in the river gravels 

generally require lining to prevent excessive loss.

River gravels that occur along the valley bottoms 

have high ground-water and at such places, drainage 

difficulties may be encountered in excavations more 

than a few feet deep.

Stability.—The river gravels have relatively low 

strength when dry although the greater admixture of 

fines locally gives a higher internal friction than is 

commonly found in the uncemented portions of the 

bench deposits. Most high-angle cuts crumble and 

slump if they are left unsupported.

Workability.—Except in the vicinity of Alpine, the 

river gravel beds are not consolidated and can be easily 

excavated.

MIXED GRAVEL AND SAND

Most of the deposits of mixed gravel and sand (shown 

on plate 2 by the symbol gr-ss) lie along the outer 

margins of the deltas. Most of these deposits are 

composed of sloping beds of sand and small gravel 

capped by horizontal layers of coarser gravel (as much 

as 2 inches in diameter).

Permeability and drainage.—The gravel-sand deposits 

are very permeable. Some lime cement is present in the 

coarse horizontal gravel layers, but the quantity is not 

enough to impede drainage. Except near their contacts 

with silt and clay deposits, these deposits lie above the 

permanent ground-water table. Even near the silt-clay 

boundaries, excavations less than 10 feet deep will be 

well drained.

Stability.—The uncemented gravel and sand deposits 

have low internal friction when dry. They are unstable 

in high-angle cuts.

SAND

The sand deposits occur in the deltas and in bars in 

front of them. On the map (pi. 2) they are shown by 

the symbol ss. The sand is usually moderately rounded 

and poorly to fairly graded. Appreciable quantities of 

silt and clay are found in the areas on the Highland 

bench east of Dry Creek and at the north end of most

of the bars. Elsewhere the percentage of fines is 

relatively low.

Permeability and drainage.—Permeability is moderate 

to high and drainage is good except in the delta sands 

east of Dry Creek where the sand is very silty. The 

sandbars in front of the deltas generally are less than 

10 to 15 feet thick and commonly only a few feet thick. 

Beneath the sand are beds of silt or clay; there is seepage along the top of these impermeable layers.

Stability.—The sand has very little dry strength and 

is not stable in high-angle cuts. The sand areas themselves will support loads with little settling, but heavy 

foundations in all the sand-bar areas would probably 

need deep piling or other types of support because of 

the underlying silt and clay. Some of the buildings of 

the Geneva steel plant are located on a broad shallow 

bar (sec. 8,T.5S.,R.2E.) and required deep piling in 

order to insure safe foundations.

SILT AND CLAY

The deposits of silt and clay are lake deposits, shown 

on the map (pi. 2) by the symbol si-cl. Mechanical 

analyses (fig. 13) indicate that the material is a lean 

clay with some variations to clay loam and to medium 

or heavy clay and includes little material that could be 

classified as true silt. Close to sandy areas the material 

may be transitional to sandy clay. These silt and clay 

deposits are more widely distributed over Utah Valley 

than any other material. They are most extensive in 

the low areas bordering Utah Lake.

Permeability and drainage.—The silt and clay have 

rather low permeability; drainage is fair to very poor. 

Canals or other water-control structures excavated in 

these materials generally show little water loss even 

where the ground-water table is considerably below the 

canal bottom. Although the texture of the silt and 

clay produces poor drainage, their topographic location 

and expression are of prime importance in determining 

the drainage difficulties which may be encountered in 

construction.

The silt-clay bodies which lie at or above the level 

of the Highland and Orem benches are topographically 

favorable for good drainage. They have pronounced 

slopes which are mostly greater than 5 percent and less 

than 15 percent, although some slopes are as steep as 

30 percent. Surface runoff is good and the ground does 

not become saturated with water below the upper 

2 or 3 inches except after unusually long steady rains or 

melting of snow. These areas are generally underlain 

by permeable alluvial fan material in which the 

permanent water table is more than 100 feet deep.

On the other hand, the silt and clay in front of the 

benches underlie land which is not much higher than 

Utah Lake, and ground-water level is commonly within
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PERCENTAGE CUMULATIVE 

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PERCENTAGE CUMULATIVE V N \ \

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52 LAKE BONNEVILLE

a few feet of the surface. Moreover these areas are so 

nearly flat that runoff is very slow. Heavy or prolonged rains saturate the ground and commonly leave 

standing water wherever there is a slight depression. 

Marshy, even boggy, ground is found in many places.

Stability.—The silt and clay deposits have a moderate 

to high dry strength, depending on amount and grading 

of the clay present. Shearing strength of the wet 

material is uniformly low. In general this material is 

poor for foundations. Heavy loads will settle appreciably unless supported by piling. Excavations 

generally hold vertical walls as long as the material 

remains dry. Moderate slopes usually maintain themselves when wet, although they gully readily under 

heavy rains.

Near the cities of Provo, American Fork, and Lehi, 

the foundation conditions are somewhat better than in 

most of the other silt and clay areas, because the silt 

and clay beds are commonly underlain by gravel 

deposited in former flood stages by the Provo River, 

American Fork River, and Dry Creek. Wherever the 

silt and clay cover is known to be less than 10 feet deep, 

this condition has been indicated on the engineering 

geology map (pi. 2) by a striped pattern combining the 

symbols for the overlying silt and the underlying gravel. 

By the nature of their origin as flood deposits, the 

extent and thickness of the gravel beds are highly 

variable. Because of this variability of materials 

beneath a 3- to 20-foot cover of silt and clay, foundation 

conditions must be determined by drilling and testing.

Workability.—The dry silt and clay can be readily 

excavated. Even the hard heavy clays can be easily 

handled with power tools although the handling, of 

course, is more difficult where the ground-water table 

is high.

UNSORTED MATERIALS (AliLTJVIAJL-FAN DEPOSITS)

The alluvial-fan deposits that are shown on the map 

(pi. 2) as gr-cl include alluvial fans of pre-Lake Bonneville age as well as some of the post-Provo alluvial deposits built by small streams at the mountain 

fronts. The alluvial-fan deposits are almost entirely 

unsorted mixtures of angular and subrounded rock 

fragments with varying percentages of silt, sand, and 

clay. The percentages of coarse and fine material 

differ greatly with each deposit. Some have less than 

20 percent silt and clay; in others as much as 90 

percent of the material is fine sand size or smaller.

Permeability and drainage.—In the fan material 

fronting most of the Traverse Mountains and along the 

Wasatch Range north of Linden, the percentage of 

silt, clay, and fine sand commonly exceeds 50 percent. 

The permeability in these deposits is low and drainage 

is only fair to poor. Water-control structures commonly show reasonably low losses, less than 14 percent, but the deposits are irregular and very permeable 

material is present locally. In these areas excavations 

for foundations probably would drain slowly. However, 

the drainage conditions generally are satisfactory 

because the topography favors runoff and the groundwater table is generally low.

The two areas in which the fan deposits show the 

most extreme local variations in the percentage of fines 

are the benches south of the latitude of Linden and in 

the SEK sec. 24, T. 4 S., R. 1 W. immediately east of 

Point of the Mountain. At many places within these 

areas the fine fraction makes up less than 30 percent 

of the total volume. Correspondingly, there is a 

wide range in permeability; limited areas in which 

canals and reservoirs may require lining to prevent 

excess water loss are fairly common.

Stability.—The wet strength of the fan materials 

is generally fair to good. Dry strength is fairly high 

in areas north of the latitude of Linden; in deposits 

along the mountain front southeast of Linden, where 

the percentage of fines is lower, the dry strength is 

probably moderate to fairly low.

The material is fairly stable in high-angle cuts and 

will stand with little or no support. Stability under 

heavy load is generally fair, although where the 

percentage of fines is high there might be appreciable 

settlement.

Workability.—Most fan material is easily worked 

except in local areas along stream courses where 

large boulders may be encountered.

CONSOIJDATED ROCKS

TERTIARY FORMATIONS

The Tertiary beds are mostly volcanic tuff, sand, and 

clay and are exposed only in the Jordan Narrows. For 

the purpose of this report these beds are grouped 

together although they show a wide range in properties. 

In general, the Tertiary formations are not hard rocks 

which require heavy blasting for excavation, but they 

are better consolidated than any of the younger 

formations except the local areas of travertine and 

heavily lime-cemented gravels. Their permeability is 

considerably lower than the younger sand and gravel 

but is equal to or slightly greater than the silt and clay 

of the Lake Bonneville group. Most of the tuff, 

sand, and clay will stand at high angles in fresh cuts. 

Weathered slopes are subject to minor slumping and 

sloughing. They appear to be adequate in excavations 

or as road foundations but their limited occurrence 

offers little opportunity to judge general foundation 

conditions.

Consolidated tuff and lava blocks, also probably of 

Tertiary age, are exposed only in the SW% sec. 2, T. 5
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 53

S., E. 1 W. These rocks are harder than any of those 

in the Jordan Narrows and stand in high-angle to 

vertical cuts without slumping.

PALEOZOIC FORMATIONS

Paleozoic rocks (map symbol Pal, on pi. 2) form the 

mountains surrounding Utah Valley. Limestone and 

quartzite are abundant. They are generally very hard, 

dense, and massive except locally where they have been 

sheared and broken by faults. Locally along some of 

the major faults, the quartzitic formations have been 

pulverized to flour-size material.

Shale beds (Manning Canyon shale) are moderately 

extensive. They are commonly covered by several 

feet of overburden, because they erode and weather 

rapidly. A line of seeps and springs occurs where the 

shale is overlain by pervious rocks. Where water penetrates the shale along fault or bedding planes, or permeates the weathered overburden, the material becomes 

very unstable and steep natural or artificial slopes are 

liable to landslides and mudflows. Part of the irrigation canal along the front of the Wasatch Range was 

cut into beds of Manning Canyon shale; landsliding of 

these beds has moved this section of the canal more 

than 50 feet from its original alinement.

CONSTRUCTION MATERIALS (UNPROCESSED)

Unprocessed construction materials include those 

earth materials suitable for concrete aggregate, for fill, 

base course, or surfacing of highways, and riprap. 

The materials must be excavated and transported but 

they are used without further processing except for 

crushing, screening and (or) washing in order to obtain 

a desired sizing. Figure 14 shows the location of 

quarries and pits of various kinds in northern Utah 

Valley and figure 15 shows some of the different types 

of gravel.

BENCH GRAVEL

Concrete aggregate.—Although most of the bench 

gravels, except the granite-bearing gravel along Dry 

Creek, have good physical and chemical soundness 

and generally acceptable roundness and grading, nearly 

all the deposits are considered unsuitable for concrete 

aggregate because of the prevalence of calcium carbonate deposited on and between the gravel pebbles. 

The coatings, which partly or entirely cover the 

pebbles, are enough to prevent good bonding of the 

cement even where the actual percentage of calcium 

carbonate may be very low.

Some of the high bench gravels near the mountain 

front and some of the Point of the Mountain deposits 

may have a sufficiently low percentage of lime to be 

acceptable for concrete aggregate but should be tested 

for other undesirable properties. For example, some

gravels north of American Fork canyon which are 

composed of limestone, dolomite, hard shale, and 

quartzite show high losses in the dolomite and shale 

fractions under the sodium sulfate test 1 indicating 

that they would give only fair resistance to freezing 

and thawing in the field.

Some of the gravel benches in front of the Lake 

Mountains contain more than 50 percent flat and 

elongate pebbles. Although this feature may be sufficiently serious to cause rejection for most concrete 

work, the gravels seem otherwise acceptable. Most of 

these deposits are largely free from the heavy lime 

coatings characteristic of the bench gravels on the 

east side of Utah Valley.

Surfacing and base course materials.—The bench 

gravels are widely used on the principal highways as 

base course under bituminous or concrete paving and 

as surfacing on secondary roads. They commonly 

require some screening to exclude oversize material 

(generally, that greater than \% inches in diameter). 

Some of the deposits close to the Wasatch Range 

contain a high percentage of very coarse gravel and 

large cobbles and, at present, commonly are avoided 

in favor of other deposits which require less crushing 

and screening. Farther from the mountains, the 

proportion of oversize material diminishes although in 

some places the bench gravels still lack enough sand 

and fine gravel to furnish the well-graded aggregate 

desired in construction. This deficiency in fines can 

be, and commonly is, corrected by running the material 

through a portable crushing and screening plant at the 

pit to obtain the required sizing.

Outcrops are numerous along stre.am valleys and 

gullies, and new gravel pits can be developed easily by 

sidehill excavation. In most places overburden is 

almost negligible, commonly ranging from a few inches 

on the slopes to a few feet of gravelly soil on the tops 

of the benches.

Fill.—The bench gravels form good pervious backfill. It is commonly necessary to add fines to make a 

satisfactorily stable embankment-type fill. The gravels 

require high moisture content, often complete saturation, to obtain maximum compaction.

Riprap.—Very little material in the bench gravels is 

suitable for riprap. Some of the large cobbles on the 

benches along the front of the mountains arid along the 

railroad cuts in the SWK sec. 25, T. 4 S., R. 1 W., east 

of Point of the Mountain may be suitable for riprap 

along railroad or highway embankments or on the 

downstream faces of earth dams. Some gravel layers 

at Point of the Mountain are so thoroughly limecemented that they form a hard rock that may be used 

for some types of riprap. Because of the disintegrai Data furnished by Bureau of Reclamation field office at Pleasant Grove, Utah.
54 LAKE BONNEVILLE

R.I E. R.2 E. R.3 E.

Large gravel and sand pits 

(Excavations larger than 100,000 cubic yards

Moderate size gravel and sand pits 

(Excavations between 10,000 and 

100,000 cubic yards)

Small gravel ' and sand pits 

(Excavations smaller than 10,000 cubic yards)

X

Clay workings

Limestone quarry

FIGURE 14.—Map showing location of pits and quarries in northern Utah Valley.
R2E. R. 3 E.

EXP

Angulor, very poorly 

clay content varying 

more than 80 perc

a fraction of on in

in diameter

Rounded,moderately 

sond with silt ond c

10 percent. Most of 

inches in diameter

6 inches in diamet

Predomin

Predominan

Two-thirds quartzite; o

One-half quortzite; on

Four-fifths quortz

dolomite; a s

Variable; domin

quortzite 

Dominantly quartzite

chert, o

_l_ Dominantly volcanic ro

of limes

Dominantly bla

amoun

R.2 E. R.3 E.

FIGUEE 15.—Map showing differences in types of gravel in northern Utah Valley.
56 LAKE BONNEVILLE

tion and solution of the lime cement, this material 

probably is not suitable for riprap which is in constant 

contact with water.

RIVER GRAVEL

Concrete aggregate.—The majority of the river gravel 

deposits contain hard, physically and chemically sound 

pebbles with very small quantities of deleterious 

minerals or harmful surface coatings and are considered suitable for concrete aggregate. In general 

these gravels contain enough silt and clay that they 

require washing before they can be used.

Most of the aggregate that has been used in construction requiring high-quality concrete work has 

come from the river gravel deposits. The largest 

operations are the pit now being worked by Owen 

Dean and Sons in the American Fork River channel 

(boundary between sees. 12 and 13, T. 5 S., R. 1 E.) 

and the pits which were opened nearby in the floodplain deposits (SWHSEtf sec. 13, T. -5 S., R. 1 E.) 

for the concrete construction at the Geneva Steel Co. 

plant.

The most satisfactory deposits are along American 

Fork River. They begin about a mile and a half 

southwest of the mountain front and extend roughly to 

the town of American Fork. In this zone the gravels 

carry lower percentages of cobbles, boulders, and oversize gravel than is found closer to the mountains, and 

do not contain the excessively high quantities of silt 

and clay that occur in the more southerly parts of the 

fan. The river-deposited gravels in the vicinity of 

Alpine have an appreciable percentage of decomposed 

granite pebbles and commonly are coated with a heavy 

deposit of calcium carbonate. The gravels of the 

Provo River contain considerable lime carbonate and 

commonly are overlain by 10 feet or more of silt and 

clay which would have to be removed by stripping.

Surfacing and base-course materials.—Most river 

gravel deposits are similar to the bench gravels in their 

suitability as coarse aggregate for surfacing or base 

course. The gravels along Dry Creek north of Alpine 

and the channel deposits of American Fork and Provo 

Rivers near the mountain front contain many large 

boulders and cobbles and require crushing and screening 

before they can be used.

Fill.—The river gravels can be used for pervious 

back fill. The deposits which lie a mile or more west 

of the mountain front probably contain enough intermixed or interbedded silt, clay, and fine sand to make 

stable embankment fill.

Riprap.—The coarse cobbles and small boulders in 

the river gravels near the mountain front along Provo 

River, American Fork River, and Dry Creek are suitable for light riprap. They have been used along irrigation ditches and canals. However, these deposits do 

not contain enough material of suitable size and shape 

to be of more than very local importance.

MIXED GRAVEL AND SAND

Concrete aggregate.—The deposits of mixed sand and 

gravel are largely composed of sand and moderately 

to well-rounded rock and mineral fragments. Although 

the individual beds which range from a few inches to 

a few feet thick commonly are poorly graded, the average product of a working face in a pit from 10 to 30 

feet high gives a moderately to well-graded aggregate.

The coarse fraction (retained on a no. 4 screen) 

generally comprises from 10 to 35 percent of the total 

and in size from % to 2 inches, although scattered pebbles are larger. It varies in composition according to 

its source area in the mountains. The deposits east 

and south of Mitchells Hollow are composed almost 

entirely of hard, sound quartzite and limestone. West 

of Mitchells Hollow, the deposits contain some granite 

derived from the mountains at the head of Dry Creek. 

The granite commonly is decomposed and breaks up 

into separate mineral grains under pressure of the 

fingers. Most deposits contain less than 5 percent of 

granite but immediately west of Alpine some beds 

contain as much as 50 percent granite.

The fine fraction contains almost no clay-size fines 

and in some pits is deficient in material lying between 

the no. 30 and no. 200 sieve sizes. Except in the 

granite-bearing areas where feldspar sand grains are 

common, the particles are mostly subrounded quartz 

grains.

The principal objection to most of these deposits as 

a source of concrete aggregate is the prevalence of 

calcium carbonate cement in the upper 2 to 10 feet. 

Although this cement is much less abundant than in 

most of the gravel areas, there is enough to interfere 

with the good bonding desired for high-quality concrete work. A product made by mixing the cleaner 

lower beds with the coarser, lime-stained overlying 

layers is used locally for concrete in the construction 

of small buildings and appears to be satisfactory for 

this type of use.

Surfacing and base-course materials.—The mixed sand 

and gravel is a satisfactory material for highway construction. However the addition of some clay binder 

probably is desirable to make it more stable when used 

as gravel surfacing.

Fill.—These deposits are similar to the bench gravels 

in that they form good pervious backfill but are probably unsatisfactory in embankment fills without the 

addition of a clay and silt binder.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 57

SAND

Fine aggregate.—The wide changes in percentage of 

silt and clay admixed and interbedded with the sand 

results in considerable variation between deposits in 

suitability for fine aggregate.

Probably the best deposits are on the Highland bench 

north of Lehi (NW^NE}£ sec. 5, T. 5 S., R. 1 E.) and 

on the north end of the Orem bench. These deposits 

are predominantly clean loose quartz sand, although 

fragments of feldspar derived from the granite and carried in by Dry Creek are fairly common in the deposit 

north of Lehi. Both are generally overlain by limebearing gravel from a few inches to 1 or 2 feet in thickness, but apparently only small amounts of calcium 

carbonate remain in the sand. The sand north of Lehi 

has been used satisfactorily in small-scale concrete construction.. Small pits have been developed in the Orem 

bench but no service records of the materials are available.

The sand (882 on pi. 2) in the central part of the 

Highland bench appears to be unsuitable for use as 

fine aggregate because of the large percentage of silt 

and clay. The sand grains are predominantly less than 

1 mm in diameter. The silt and clay mixed with the 

sand commonly average 15 to 35 percent of the total 

volume but in places constitute 70 percent.

The sand bars in front of the benches are composed 

chiefly of uniformly rounded, poorly graded quartz 

sand. The bar sands are moderately free from silt except near their tips at the north end of the Orem bench 

and the west end of the Highland bench, where the silt 

content locally exceeds 25 percent. The silt-free parts 

of the sand bars have been used locally in concrete 

mixes for small house and garage foundations.

Surfacing and base-course materials.—The texture of, 

the sand deposits is too fine to be satisfactory for surfacing or use as base-course, but the sand is suitable 

for mixing with coarse aggregate.

Fill.—The silt-free sand could be used for pervious 

backfill but it would not be stable in embankment fills 

without addition of silt and clay for binder. Although 

not highly impermeable as a whole, the high-silt sand 

probably would make good fill if provision for adequate 

drainage is made during construction. The high-silt 

sand compacts fairly well and is moderately stable in 

embankment fills.

SILT AND CLAY

Fill.—Silt and clay commonly are used as fill and 

subgrade in many parts of Utah Valley and probably 

could also be used for puddle cores in earth dams. The 

silt-clay deposits can be highly compacted under optimum moisture content which is generally high (20 percent or more). Permeability of the compacted fill is

low. The silt-clay deposits have relatively low shearing strength and require thorough compaction when 

used as embankments.

Binder material.—The silt and clay is useful as binder 

for coarse aggregate on gravel-surfaced roads.

UNSORTED MATERIALS (ALLUVIAL-FAN DEPOSITS)

Concrete aggregate, surfacing, and base-course.—The 

high percentage of silt and clay in most of the fan deposits render them unsuitable for concrete aggregate or 

for high-grade base-course and surfacing. The coarse 

fraction is generally composed of unsorted, angular 

rock fragments which could not be used without considerable washing, screening and crushing.

The fanglomerate benches a half mile east of Point 

of the Mountain (SEtf sec. 24, T. 4 S., R. 1 W.) may 

contain more suitable materials. They are composed 

largely of angular to subangular sand and small gravel 

with no more than a few percent of silt and clay. 

These deposits have not been worked commercially 

although they have been prospected at several places.

Fill.—The material in most of the fan deposits is 

suitable for backfill and embankment fill. The mixture 

of silt, clay, and rock compacts fairly well. The admixed rock fragments give it a considerably higher 

strength than a silt and clay fill. In general the alluvial fan material can be readily worked with power 

tools although locally large boulders and cobbles are 

numerous.

Riprap.—Local concentrations of boulders and cobbles along the shallow stream channels that cross the 

fans are a possible source of riprap. However the 

quantities of material of suitable size and shape are 

probably very limited.

CONSOLIDATED ROCKS

TERTIARY FORMATIONS

The Tertiary formations crop out only in very limited 

areas, and they are unimportant as sources of construction materials. Furthermore, the rock types present 

are inferior in quality to most other materials available 

in the valley for concrete aggregate, base-course, or fill.

PALEOZOIC FORMATIONS

Concrete aggregate, base-course, surfacing, and fill.— 

Quartzite and limestone in the mountains surrounding 

Utah Valley are generally hard and tough and would 

form sound aggregate material if crushed. These 

sources for crushed rock have not been used, however, 

because adequate supplies of clean rounded gravels are 

more accessible. Moreover, the quartzite especially 

tend to break into sharp angular fragments which 

would require a considerably higher proportion of 

cement than that needed to make workable concrete 

with more rounded aggregate. Although the granitic
58 LAKE BONNEVILLE

pebbles in the valley deposits commonly are much 

decayed, the fresh outcrops of granite along the head 

of Dry Creek probably would crush to make a firm 

satisfactory aggregate. The Manning Canyon shale 

has been used fairly successfully as fill.

Riprap.—The limestone, quartzite, and granite of 

the mountains are inexhaustible potential sources of 

riprap, but generally can be obtained only by blasting 

and quarrying. In some places, the talus from the 

bedrock would give a limited quantity of irregular 

blocks and fragments for such local construction as 

small check dams, but could not furnish a large supply 

of uniform quality material.

Limestone Jar flux—In the SW#NE% sec. 31 T. 6 S., 

R. IE. on the east flank of the Lake Mountains, limestone is being quarried and crushed for use as flux in 

iron and copper reduction.

Canal lining.—The Manning Canyon shale is the 

most satisfactory material in the area for lining irrigation canals to reduce water losses where the canals pass 

through highly porous deposits. The Bureau of 

Reclamation found that weathered shale mixed with 

soil not only sealed off pervious material faster than 

fresh shale but the admixed rock fragments of the 

overburden also acted to make the seal coat less easily 

eroded by the water.

CONSTBUCTION MATEBIALS (PBOCESSED)

Construction materials processed by some means 

other than washing and screening include the clay and 

shale deposits which furnish raw materials for the 

manufacture of house brick and low-grade refractories, 

and the calcareous tufa (travertine) east of Pleasant 

Grove which was used as a building stone in pioneer 

days.

Cl^AY AND SHALE

The deposits that have been the principal sources 

for clay in Utah Valley are of two kinds: beds of clay 

laid down in Lake Bonneville, and shale formations 

(Manning Canyon shale) in the older rocks that occur 

in the mountains bordering the valley.

Lake silt and clay.—The lake clays which overlie the 

gravels in and around the city of Provo are being used 

for brick by the Provo Brick and Tile Co. The company's pits are north of town (Fig. 14) in the NW%SE% 

sec. 36, T. 6 S., R. 2 E.

The clay ranges from lean to medium clay in composition. It turns pale yellow on firing and is satisfactory 

for ordinary building construction.

The distribution of this type of material is widespread throughout the valley. Mechanical analyses 

and simple testing for firing qualities could readily be 

made to determine new supplies as they are desired.

Some clay exposed in Dry Creek (NW)£SE% sec. 34, 

T. 4 S., R. 1 E.) show a considerably higher percentage 

of clay minerals than usually occurs in the lake sediments. However, it appears to be of limited occurrence and would require stripping 6 to 15 feet of gravel 

and soil overburden.

Paleozoic shale.—Although a considerable amount of 

exploration has been done, no materials suitable for 

high-quality refractory brick and tile have been found 

in the north half of Utah Valley. However, the black 

shales that occur with the limestone and quartzite 

Paleozoic formations around the edge of the valley 

have refractory qualities and are being used as furnace 

lining in some of the smelters of Salt Lake Valley.

The largest shale pits are along the front of the 

Wasatch Range and Lake Mountains (fig. 14) and are 

accessible by road. The occurrence and size of these 

deposits are irregular because they occur in fault blocks 

in the midst of other fault blocks composed of limestone 

or quartzite beds. Generally the shale itself has been 

severely shattered and crushed by the faulting.

Most development has been by sideliill cuts. On 

steep slopes, the overburden is commonly lacking or at 

most is only a few inches thick. On gentle or flat 

slopes, the fresh shale is covered by a few feet or less of 

rocky soil and weathered shale. The shale can be 

removed readily by power shovels, bulldozers, or other 

power tools with little or no blasting required.

Clay developed on ancient soils.—A type of clay 

deposit discovered quite accidentally in connection 

with this study may prove to be a useful source of raw 

material for brick and structural clay products. The 

data in this section are taken from a preliminary report 

by Hunt, Creamer, and Fahey (1949, pp. 120-122). 

* The clay formed as an ancient soil prior to Lake 

Bonneville and is found only at those places where the 

land surface has been preserved since pre-Lake Bonneville time without being either eroded or buried by 

other sediments.

The ancient soil, where preserved in its entirety, is 

deep. The clay occurs in the upper part and in places 

is 10 feet thick. Beneath the clay is another 20 to 30 

feet of strongly lime-enriched weathered parent material, the top of which would form the bottom of pits 

that might be opened in the clay. The clay comprising 

the upper layer of the old soil is practically free of lime 

but does contain considerable iron-oxide. The clay 

mineral is believed to be largely illite but much more 

study of the mineralogy is needed before any generalizations can be made regarding the mineral or chemical 

composition of the deposits.

The texture of the clay, or its content of sand aggregate varies considerably, depending on the kind of 

parent rock from which the old soil was formed. The
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 59

soil is known to have formed on limestone, shale, 

granitic rocks, lavas, and mixtures of these. The 

parent rocks except for their quartz or other resistant 

minerals were completely altered to clay by the soilforming process. Where, for example, the soil developed on a shale formation, very little sand aggregate 

remains and more than 90 percent of the clay can be 

washed through a 325-mesh sieve. Where the soil 

developed on gravel or other deposits containing much 

quartz this material remains with the clay. Sixty to 

seventy percent of this kind of clayey material can be 

washed through a 325-mesh sieve. Depending on the 

proportion of aggregate desired in the clay, prospecting 

would be guided by the kind of parent rock under 

these upland surfaces.

Three samples of the clay were tested by the 

National Bureau of Standards (Hunt, Creamer, and 

Fahey, 1949, p. 121):

Sample A. Old clay soil developed on the oldest of the 

glacial moraines, above Alpine. Parent 

morainal material largely granitic; mica 

content of clay 5 to 10 percent. Sample 

taken by auger 18 to 36 inches below 

surface.

Sample B. Old clay soil on fanglomerate composed of 

granite, latitic lava, limestone, and quartzite gravels. Sample from near reservoir 

in Traverse Mountains 2 miles northwest 

of Alpine. Sample from 12- to 48-inch 

depth.

Sample C. Old soil formed on Manning Canyon shale. 

South side of Provo Canyon, by Pole 

Canyon road 2 miles from Provo Canyon 

road.

These three clays were found to have properties 

suitable for the manufacture of common brick and 

structural clay products with a maturing range from 

about 1000° to 1075° C. (approximately 1830° to 

I9600 F).

The results of a sieve analysis are given in the 

following table:

drying shrinkage previous to being heated to 1000° C. 

in an electric furnace. The results are tabulated 

below.

Sample No.

A

g

£

Retained 

on 100- 

mesh sieve

19. 2

11. 15

3.9

Retained 

200-mesh 

sieve

8. 2

10.3

1.0

Retained 

on 325- 

mesh sieve

6.5

9. 15

2.2

Passing 

325-mesh 

sieve

66. 1

69.4

92.9

The material which passed through the 325-mesh 

sieve was used for making one set of test bars and for 

the determination of the water of plasticity. The test 

bars were dried at 110° C. They were measured for

24773—54———5

Sample No.

A. ____________

B_____________

C-__-___-_.-_

Shrinkage 

during 

drying 

(percent)

8.4

9.2

Total 

shrinkage at 

1000° C. 

forlhr 

(percent)

13.2

12.5

10.2

Color after 

heating

Brown-red____

Brown-red _ _

Salmon _ ____

Water of 

plasticity 

(percent)

29.2

26. 1

29.4

Some of the clay was used without sieving to make 

a second set of test bars. These bars were heated to 

1100° C. for one hour.

Sample No.

A____.___ — — _-__ — —

B_________________-__--__

C-._ — — — — — — —

Fired

shrinkage at

1100° C.

for 1 hr

(percent)

7.5

7. 1

12.4

Color

Dark red-brown.

Do.

Dark red.

Because the deposits are remnants of a land surface 

that has been modified by erosion, their size and shape 

vary widely. The thickest and most extensive deposits occur on smoothly rounded upland surfaces 

where several feet of clay may extend over several 

acres. Some individual deposits already known contain 

many tens of thousands of cubic yards of clay.

The clay occurs at the surface with no more than a 

few inches of recent rubble or humus above the clay. 

Hand augers are adequate for determining the quality, 

extent, shape, and thickness of a deposit.

In general the lime-rich zone that is beneath the clay 

and that would form the floor of a pit is undulatory 

and slopes toward the present valleys. Rarely can a 

level floor be expected under these clay deposits. 

The slope of the floor, however, generally is less steep 

than the present land surface so the deposits generally 

thicken in a direction away from the present valleys.

One of the most accessible deposits is found in the 

eastern part of the Traverse Mountains immediately 

northwest of Alpine. This clay contains considerable 

aggregate, in part pebbly. It was developed from 

gravel deposits containing pebbles of limestone, quartzite, granite, and latitic lavas. Similar high-aggregatebearing clays that form directly on bedrock formations 

of limestone, quartzite, and latitic lavas occur in the 

western part of the Traverse Mountains; other deposits 

occur in the Wasatch Range.
60 LAKE BONNEVILLE

CALCAREOUS TUFA (TRAVERTINE)

During the early settlement of Utah Valley, many 

homes and farm buildings were constructed of calcareous tufa quarried from a hillside northeast of 

Pleasant Grove in the NE^NEM sec. 17, T. 5 S., R. 

2 E. The tufa is a spring deposit formed by the 

cementation of fragments of Paleozoic shales, pre-Lake 

Bonneville fanglomerate, and probably some younger 

materials into a relatively solid, hard calcareous rock. 

The tufa is referred to locally as "pot stone" or "pot 

rock."

The tufa is very porous and, when first quarried, is 

soft enough to be trimmed and shaped with an axe but 

it hardens rapidly on exposure. It appears to be 

durable for light construction under the semiarid 

climate of Utah Valley. Some of the older houses 

which have been standing 80 years or more show only 

slight effects of weathering. Because it is highly 

vesicular, the tufa would not be suitable for foundation 

material in continuously wet ground.

The largest exposure of tufa is a few hundred yards 

square. About half the deposit has been removed. 

However, little or no tufa-block construction has been 

done in the valley in the last 50 to 60 years since brick 

became cheap and plentiful.

CALCITE

A small mine, in the SE^SWM sec. 30 T. 6 S., R. 

1 E. on the east edge of the Lake Mountains, has been 

opened in a calcite vein 8 to 15 feet wide. The bedrock 

bordering the vein is dense black limestone. Part of 

the material is removed by an open cut extending 

along the vein. Underground operations are also 

being used to work the deeper parts of the deposit.

The calcite is coarsely crystalline and is cloudy white 

to light gray. No large crystals of optical quality 

have been found. The calcite is run through a crusher 

at the mine and is used in chicken feed.

SEISMIC ACTIVITY IN UTAH VALLEY

Utah Valley has been, and no doubt will continue to 

be, an active seismic area. Heavy construction needs 

to consider and safeguard against the possibility of 

earthquakes.

Except near the extreme margins of the valley, the 

foundations of all construction must necessarily be in 

unconsolidated silt, sand, and gravel. Such materials are probably the most undesirable medium for 

heavy construction in seismically active areas because 

the effective intensity of earthquake waves propagated 

through unconsolidated sediments is far greater than in 

solid rock.

Earthquakes of varying intensity have been recorded 

in Utah since the earliest days of settlement. Information in this report regarding the history of earthquakes 

was furnished by J. Stewart Williams, Utah Agricultural College, Logan, Utah. Prior to the installation 

of the seismograph at the University of Utah in 1907, 

there was no instrumental record, but the Deseret 

News has provided good descriptions of nearly all 

earth tremors affecting the State since 1853. At 

least 123 different earthquakes have occurred in Utah 

since that date; 34 of them apparently centered along 

the front of the Wasatch Range and some of these 

affected Utah Valley.

Earthquakes having intensities as great as IX 

(Rossi-Forel scale) and affecting tens of thousands of 

square miles have occurred in other parts of Utah. 

But most tremors that apparently centered along the 

front of the Wasatch had intensities from III to V; 

six had intensities between V and VII. The highest 

recorded in Utah Valley is V, but it should be recalled 

that these records cover less than 100 years.

WATER RESOURCES

By HAROLD E. THOMAS 

INTRODUCTION

Water and productive soils constitute the natural 

resources of preeminent importance to Utah Valley. 

Because there is far more arable land than can be irrigated from available water supplies—a characteristic 

common to most of the intermontane areas in the arid 

West—water is the limiting factor in the agricultural 

economy which has dominated the area since the first 

Mormon pioneers entered the valley in 1849. Water 

is also one of the major factors that will determine the 

pattern and set the limit to the currently expanding 

industrial development and to the growth of communities to service those industries. Utah Valley is fortunately situated where it can harvest the water crop 

of tributary drainage basins that include high mountains with abundant precipitation. So productive are 

these drainage basins that in comparison with adjacent 

areas the valley is exceptionally well provided with 

water, and a surplus accumulates in Utah Lake which 

is appropriated by water users in Jordan Valley to the 

north.

Utah Valley is a part of the drainage basin of the 

Jordan River, which extends over five counties (Salt 

Lake, Utah, Juab, Wasatch, and Summit) and includes 

more than half the population of Utah. The Jordan is 

first among the drainage basins of the State in quantity 

of surface water utilized for irrigation and other purposes. It also leads the State in the number of wells 

and in the quantity of ground water discharged from 

wells and springs.

The northern part of Utah Valley is, in several respects, a distinctive part of the Jordan River drainage
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 61

basin. The largest stream in Utah Valley, the Provo 

River, is also the largest contributor to the Jordan River 

system. American Fork River is the third largest 

tributary in the system. Several of the minor streams 

have less seasonal variations in flow than is common in 

most streams in Utah. Battle Creek near Pleasant 

Grove furnishes water on a schedule that is nearly 

ideal for irrigators, the discharge coming from springs 

that probably are fed from high snow fields on Mount 

Timpanogos and that reach their maximum discharge 

in the latter part of the irrigation season, long after the 

freshets of most streams. Excellent wells are also 

obtained in northern Utah Valley, and the average 

discharge per well is higher than in any other major 

ground-water reservoir in the State.

Because there were few water-shortage problems, 

and because the ground-water reservoir seemed inexhaustible to them, early settlers saw no need for 

determining the occurrence, movement, or quantity of 

water available for utilization. There is, therefore, 

very little factual information concerning the water 

supply during the first half-century of development. 

Even today there are continuous records of discharge 

for only the larger streams. For several smaller 

streams, diversions are made on an established fractional 

basis, without knowledge of the quantity being discharged by the stream.

Far less is known about the ground-water supplies, 

and particularly the close relationship between groundwater and surface-water supplies. Practically no data 

concerning wells were collected during the first 85 

years of settlement. After the enactment of a groundwater law in 1935, the Utah State Engineer obtained 

from well owners records concerning the depth, diameter, date of completion, use, and estimated yield of 

each well then in existence, and since that year similar 

information on new wells has been required as part of 

the proof of appropriation of water. During the years 

1937 to 1940 measurements of discharge from wells 

were made by the State Engineer in cooperation with 

the Federal Works Projects Administration. Quantitative hydrologic studies to show the source, movement, 

and discharge of water in individual aquifers have not 

yet been made.

HISTORY OF WATER UTILIZATION

DIVERSIONS FROM STREAMS

USE OF WATER PRIOR TO 1880

According to Stover (1903, p. 93):

Soon after their settlement in Great Salt Lake Valley in 1847, 

the Mormon pioneers began the systematic settlement of other 

nearby valleys * * *. In the spring of 1849 a number of families, 

under the direction of the church, entered Utah Lake Valley. 

Thirty families located on Provo River about 2 miles west of the

present site of Provo City, and others settled near the present 

sites of Lehi, American Fork, and Pleasant Grove, on the streams 

which emerge from the mountains near those points * * *. 

Each year the amount of land brought under cultivation was 

rapidly increased and settlement extended to different parts of 

the valley. Soon the tide of settlement turned toward the 

smaller valleys lying on the tributary streams.

In 1858 the first settlement was made on the upper 

reaches of the Provo River, in Heber Valley east of the 

Wasatch Range.

The early history of the diversions from the tributaries to northern Utah Valley, the apportionment and 

use of the water, and the development of water rights, 

have been described by Stover (1903, pp. 107-144). 

The following tabulation summarizes the history of the 

principal stream diversions in the area prior to 1880, 

based largely on his report. (See table 16.)

TABLE 16.—History of principal stream diversions prior to 1880 

in northern Utah Valley

Stream

'

Drv J Creek

Diversion

Little Dry Creek.— .-

Provo city irrigation:

River bottom: 

East of river..- ... 

Park&Nuttall...

Spring Creek ———

Upper East Union. ...

Alta— -...-. ———

.....do.. — — — — -

Construction 

began i

1850

1850

1856

1856

1856

1856

1856

1862

1870 

1872

1875

1878

1851

1850

1851

1851

1851

Water diverted *

1850

1856

1864

1871 

1876

1875

1879

1851

1851

1850

1851

1877

Area 

reported 

entitled 

to water 

(acres) •

440

81,200

«380

8500

6,000

900

4,000

700 

3,500

300

650

* 6, 700

6,000

«5,000 (<)

1, 800-2, 000

1,200 («)

(•)

Area 

decreed 

entitled 

to water, 

1921 

(acres) 8

506

1

2,559

1,275

362 

81 

\ 56

574

I 352 

4,332

854 

1,880

847

1 From U. S. Dept. Agr. Bull. 124, pp. 107-144, 1903.

2 From Provo River decree, civil case 2888, 4th district court.

3 Estimated.

* Diversions from American Fork River and Dry Creek used to irrigate 6,700 acres. 

« Diversions from American Fork River supplemented by entire flow of Battle and 

Grove Creeks.

By 1880 almost the entire low-water flow of the 

several streams was being diverted, and the list above is 

therefore a nearly complete list of the principal diversions that have established primary rights to the streams 

of northern Utah Valley.

Under an act passed February 20, 1880, water rights 

were divided into classes. All rights to the use of a 

stream acquired up to the time that the sum of the 

rights is equal to the ordinary low-water flow of the 

stream are "primary" rights, and 7 years' continuous 

use gives a primary right. Those acquiring rights to 

water after the low-water flow is exhausted, or who use
62 LAKE BONNEVILLE

water during flood flows, have "secondary" rights. In 

times of scarcity holders of secondary rights receive no 

water, and whatever water a stream furnishes is divided 

among holders of primary rights pro rata according to 

their respective rights, which are based in part on the 

area irrigated and hi part on a ratio fixed by the court 

that defined the rights to the stream. This law carries 

the classification no further, but some subsequent court 

decisions carry the principle further and divide the 

rights to a single stream into several classes. In such 

cases the first class receives the water it needs; if there 

is enough water the second class takes what it needs, 

and so on until a class is reached for which there is not 

enough water. All classes below this get no water, and 

the remaining water not needed by higher classes is 

divided pro rata among the holders of rights in the class 

in which there is a shortage. Thus priorities have been 

established by group rather than by individual rights. 

Prior to 1880 the water supply furnished by the 

Provo River had been adequate for the needs of all. 

In American Fork River and Dry Creek, however, the 

late-summer flows were commonly inadequate for all 

users, and disagreements as to division of the flow arose 

as early as 1874. During the period prior to 1880 diversions from the Provo River were being increased in 

upstream areas east of the Wasatch Range (Heber 

Valley and Kamas Valley), and by 1881 the entire 

low-water flow of the river was being diverted in those 

valleys for irrigation.

STATUS IN 1903

By 1903, methods for apportionment of the flow of 

each of the larger streams entering northern Utah 

Valley had been established by court decisions. For 

American Fork River a decision of the Stake High 

Council of the Church in 1879 became the basis on 

which water was divided. The First District Court 

of the Territory in 1892 decreed the basis for proration 

of the waters in Dry Creek. For the Provo River in 

Utah Valley a decree of the Fourth District Court in 

January 1902 (the "Morse" decree) stated that no 

apportionment was necessary as long as the river's flow 

was sufficient to fill the canals to then- full carrying 

capacity as then constructed (about 370 cfs) and 

specified the basis for apportionment of lesser flow. 

The water rights on the upper reaches of the Provo 

River, which had been adjudicated by the same court 

in May 1899 (the "Fulton" decree), were not associated 

with or to any extent involved in the controversies 

over water rights on the river in Utah Valley. The 

rights on the two divisions were considered separate 

and in no way related to each other.

With respect to the Provo River, Stover (1903, pp. 

134-135) drew the following conclusions from his 

studies in 1900:

(1) That owing to the varying nature of water rights of the 

several canal interests deriving their supply of water from 

Provo River below the mouth of the canyon, and also since the 

Utah law provides that there shall be no priority among primary 

rights, the system of prorating the flow of the stream is very 

satisfactory, and is one to be commended. Steps, however, 

should be taken toward attaining greater accuracy in the measurement of the flow in the several canals, either by measuring 

weirs constructed on scientific principles or, better still, measuring flumes which have been carefully rated.

(2) That the method of distributing water from main canals 

on the time basis in localities where farms are comparatively 

small is conducive to a high duty of water.

(3) That there is an unnecessary waste of water, both in its 

distribution and in its subsequent use on the irrigated land, but 

that this waste is caused rather by the ignorance of efficient 

methods of distribution and use of water than by willful negligence on the part of the irrigator, and that by experience and 

study of existing conditions the irrigator will see the defect and 

take steps toward remedying it.

(4) That under the majority of Provo River canals entirely 

too much water is used. And along this same line it may be 

said that all measurements made during the season of 1900 go 

to show that in proportion to the amount of land irrigated the 

amount of water allotted to the river-bottom ditches is out of all 

proportion to the amount allowed the larger canals on either 

side of the river.

(5) That during the season of 1900, although complaint was 

made of shortage of water supply, the amount of water discharged by the Provo during the irrigation season, had it been 

apportioned properly, would have been adequate for the needs 

of all.

(6) That during the latter part of the irrigation season the 

supply of water in the lower reaches of Provo River is materially 

increased by return seepage from irrigated lands lying on the 

upper reaches of the stream, on which a generous amount of 

water is used during the early part of the season; and that in 

the absence of storage reservoirs, in which to store the surplus 

water of the river during the spring months, this use of water 

in the upper valleys should be encouraged.

(7) That the use of irrigation streams for the development of 

power, when such use in no way interferes with the use of the 

water for irrigation, is beneficial and should be fostered, as a 

direct means of bringing about the development of the State. 

However, where the use of water for power purposes is detrimental to the development and growth of an irrigation section, 

the use of water for irrigation should take precedence.

The State Legislature in May 1903 enacted statutes 

that declared stream waters to be public property subject to appropriation on the basis of priority, designated 

the State Engineer as the officer responsible for administration of water laws, and required subsequent appropriators to submit applications and proofs of appropriation to the State Engineer. Rights established 

prior to the passage of these statutes—which are commonly called "diligence" rights—were not required to
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 63

be recorded, but many of these rights have been defined in decrees adjudicating the rights of individual 

river basins, and others have been recorded in court 

decisions resulting from litigation over water rights.

STATUS IN 1947

Developments since 1903 have resulted in greater 

utilization of the water of the Provo River and to a 

lesser extent the water of other tributaries to northern 

Utah Valley, and have increased the water available to 

the valley by diversion from the Weber River drainage 

basin when there is a surplus. Building of dams to 

regulate the levels and permit storage in the headwater 

lakes of the Provo River was begun in 1905, and construction of canals to divert water from Beaver and 

Shingle Creeks (tributaries of the Weber River) was 

begun in 1906. Completion of the Deer Creek Reservoir in 1941 by the U. S. Bureau of Reclamation provided ample storage facilities for the water diverted 

from other drainage basins, as well as for surplus water 

of the Provo River when Utah Lake is at high stage. 

Because of this, it was possible to fulfill the requirements for water of the Defense Plant Corporation's 

Geneva Steel plant during the war emergency without 

hardship to other users of water.

The waters of the Provo River were adjudicated in 

1921 by a decree which, in the language of the presiding judge, Hon. C. W. Morse, was "the first litigation 

made on the basis of the physical unity of the stream 

from its headwaters to its mouth." This decree still 

forms the basis upon which water is distributed throughout the river system. With respect to Utah Valley 

(the "Provo division" of the river) the decree recognizes all rights established prior to May 1903 (the 

"diligence" rights) as primary or "Class A" rights, and 

awards to these rights the natural flow of the river up 

to an amount ranging from 291 cfs between May 10 

and June 20, to 209 cfs between January 15 and May 

10. Rights acquired by application to the State Engineer subsequent to May 1903 were grouped in nine 

classes (classes B to J in order of priority), and it was 

decreed that water should be distributed to classes in 

order of priority, and that whenever there is insufficient 

water to meet the needs of a class pro-rata distribution 

is made within that class, and classes of lower priority 

receive no water. Exceptions to this rule are stored 

water hi headwater lakes, water diverted from other 

drainage basins, and water used for power, which is 

recognized as "additional" use.

With respect to the effect of irrigation hi Kamas and 

and Heber Valleys upon the stream flow available to 

Utah Valley, the court found that late-summer flow in 

the lower part of the river was "greatly in excess" of

that in earlier times, and concluded that irrigation in 

the upper (Wasatch) division was responsible. The 

decree therefore defined the order of priority of water 

rights as between divisions, giving general priority to 

the established water rights in the Wasatch division as 

against all classes in the Provo division, particularly in 

early-season use.

The 1921 decree, although it adjudicated the rights 

to the flow of the Provo River, made no attempt to 

adjudicate ground-water rights in that drainage basin, 

or to define the rights of Utah Lake water users, who 

are dependent upon the Provo River drainage basin for 

a large part of their water supply. Accordingly, an 

adjudication of all water rights in the Jordan River 

drainage basin was called for in the suit of Salt Lake 

City et al. v. Tamar Anderson et al., filed in May 1936. 

Subsequently, the court placed this matter hi the hands 

of the State Engineer, charging him with preparing a 

proposed determination of all rights within the drainage 

basin. In addition to the important surface-water 

rights involved, there was also to be taken into consideration the determination of the rights to the use of 

ground water within the area. This determination was 

still in progress in 1947.

DEVELOPMENT OF WEIXS

EARLY HISTORY

It is presumed that wells were dug very soon after 

the first settlers arrived in Utah Valley, especially 

where streams, springs, or irrigation ditches could not 

be relied upon for a continuous flow of uncontaminated 

water. No records have been found concerning these 

early wells, and very few of the dug wells now in existence were constructed prior to 1880. In recent 

years many dug wells have been abandoned as community water systems have been developed and extended, and it is likely that the earlier development of 

municipal water systems by the larger towns, and of 

artesian wells in outlying areas, likewise resulted in 

abandonment .of large numbers of the old wells that 

were dug by the original settlers.

The history of development of flowing wells in the 

northern part of Utah Valley is somewhat better 

documented. James Harwood of Lehi, in a letter 

dated April 1891 to the U. S. Census Bureau in Washington, stated that he had driven the first artesian well 

hi Utah County with sledge hammers about 6 years 

earlier, using 1%-inch pipe with a steel point on the end, 

the pipe perforated at 75 feet. He obtained a flow of 

4 gpm, which continued for about 3 years and then 

ceased as other wells were driven at lower altitudes.

After the census of 1890, questionnaires were sent to 

owners of artesian wells in Utah Territory, and replies
64 LAKE BONNEVILLE

of the residents in northern Utah Valley described 115 

artesian flowing wells. About 75 of these wells were 

in the vicinity of Lehi, 15 each near Pleasant Grove and 

Lake View, and the remainder in the vicinity of Provo. 

Practically all were constructed of 1%-inch to 2-inch 

pipe, in many instances limited to the upper few feet of 

the well, with open hole below—a practice that was 

recognized at that time to result in sanding of the well 

and failure of the supply. Artesian flows were obtained at depths of 40 to 200 feet, the lesser depths 

being especially common in the vicinity of Lehi. 

Only 10 of the 115 wells had depths reported to exceed 

150 feet.

STATUS IN 1903

Richardson (1906, pp. 36, 59-75) in the fall of 1904 

included in his list of typical wells about 300 in northern 

Utah Valley, but did not attempt a complete listing. 

He estimated that there were at that time about 5,000 

flowing wells in Jordan River and Utah Lake valleys, 

of which more than half were in Utah Lake valley.

The ground-water law of 1935 required the owners of 

wells constructed prior to the enactment of the law to 

file claims for those wells that would set forth information essential to determination of water rights. According to the claims for northern Utah Valley, about a 

thousand of the wells in existence in 1935 had been 

constructed prior to 1903, and another thousand were 

completed between 1903 and 1931. Of the wells drilled 

prior to 1903, about 75 percent were located in the 

northern part of the area (the Highland district, see 

below) near the towns of Lehi, American Fork, and 

Pleasant Grove.

STATUS IN 1947

By the beginning of 1947 there were about 2,285 

wells in use in the northern part of Utah Valley, according to tabulations of the State Engineer. In 

addition, 505 wells were listed for which no use was 

claimed by the owners, many of which had been plugged 

or filled with debris; also, 105 wells drilled by the Salt 

Lake City Corp. in 1889 to augment water supplies 

in Jordan Valley had remained capped and unused 

since 1890 by order of the District Court, which found 

that those wells interfered with adjacent wells having 

prior rights.

As shown in more detail in table 17 below, most of 

the wells in use in 1947 were flowing wells less than 

200 feet deep used primarily for irrigation, and to 

supplement domestic and stock requirements. Most 

of the wells were 2 inches or less in diameter but the 

more productive irrigation wells were larger, commonly 

4 inches in diameter.

Table 18 shows the cumulative total of wells in northern Utah Valley, based on claimed dates of completion 

as filed in the office of the State Engineer. These 

totals do not agree exactly with those in table 17, because some wells have been abandoned since the claims 

were filed in 1935, and because on some claims the 

date of construction is not stated. Wells that were 

constructed and subsequently abandoned are not included in either listing if the abandonment was prior 

to 1935.

Hydrologic studies, which are discussed in more 

detail subsequently, have shown that the northern 

part of Utah Valley may be logically subdivided into 

three ground-water districts: the Provo district, comprising the alluvial and delta deposits of the Provo 

River and minor tributaries to the south; the Highland 

district, consisting chiefly of the alluvial and delta 

deposits of American Fork and Dry Creek, but including 

also the fans of Grove and Battle Creeks; and the 

Lake district, west of the Jordan River.

The Provo district includes all the area between 

Utah Lake and the Wasatch Range south of the boundary between Tps. 5 and 6 S., Salt Lake base and 

meridian. The Highland district extends north of that 

boundary to the base of the Traverse Mountains and 

west to the Jordan River. The Lake district, in which 

there has been very little ground-water development, 

embraces the area west of the lake and Jordan River.

TABLE 17.—Classification of wells in northern Utah Valley 

in 1947

[Based on claims and applications in State Engineer's office]

Use:

Stock(S)..... — ———...—-—..

Unused.. _____ . _______ .„..

Depth (feet):

100-200 _______ ... ___ _. __ ..

200-300 __ .-.——-—.__ — _-_ — .-

300-400 __ ..... _ . _ . _ . _ . ___ ..

400-500 __ —. ——— — _—— — ..

Total reported __ . ________

Diameter (inches) : 

Jetted or driven:

2^^. ..............................

3M-4-. ............... ..............

4^-5......— ......................

Dug.— .................. .———_.

Highland 

district Tps. 

4 and 5 S.

37

263

28

835

17

12

314

1,506

237

805

162

63

5

5

1,277

829

142

190

37

23

78

1,299

1,113

Provo district 

Tps. 6 and 

78.

46

296

31

680

31

8

296

1,388

87

662

150

21

16

6

942

458

231

229

79

48

44

1,089

879

Total

83

559

59

1,515

48

20

610

2,894

324

1,467

312

84

21

11

2,219

1,287

373

419

116

71

122

2,388

1,992
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 65

TABLE 18.—Number of wells in northern Utah Vattey by years 

[Based on claims and applications in State Engineer's office]

Year

I860..

1861-

1862..

1863..

1864..

1865..

1866..

1867..

1868. .

1869..

1870-

1871..

1872..

1873..

1874..

1875-

1876-

1877-

1878..

1879..

1880-

1881..

1882..

1883..

1884..

1885..

1886..

1887..

1888..

1889..

Highland district

1

1

1

1

1

1

1

1

1

1

2

2

2

2

2

3

3

3

4

4

9

12

17

20

22

61

68

72

82

190

Provo district

. _ _.

. __ .

------

......

1

1

1

1

2

3

3

3

3

3

5

6

6

6

6

8

12

14

17

22

Total

1

1

1

1

1

1

1

1

1

1

3

3

3

3

4

6

6

6

7

7

14

18

23

26

28

69

80

86

99

212

Year

1890-

1891..

1892..

1893-

1894..

1895..

1896..

1897-

1898-

1899-

1900-

1901..

1902..

1903. .

1904. .

1905..

1906..

1907-

1908..

1909..

1910..

1911..

1912..

1913..

1914..

1915-

1916..

1917-

1918-

1919..

Highland district

271

277

284

301

306

398

412

420

440

444

717

725

743

759

767

820

838

852

864

867

956

964

977

984

989

1,014

1,023

1,038

1,048

1,056

Provo district

44

44

49

50

53

70

77

81

94

97

243

253

256

269

277

310

336

347

366

374

423

451

471

481

502

540

564

576

603

615

Total

315

321

333

351

359

468

489

501

534

541

960

978

999

1,028

1,044

1,130

1,174

1,199

1,230

1,241

1,379

1,415

1,448

1,465

1,491

1,554

1,687

1,614

1,651

1,671

Year

1920..

1921..

1922..

1923..

1924..

1925-

1926..

1927..

1928-

1929-

1930—

1931..

1932-

1933-

1934..

1935-

1936..

1937..

1938-

1939.-

1940..

1941..

1942..

1943-

1944..

1945-

1946..

1947..

Highland district

1,082

1,087

1,092

1,105

1,114

1,131

1,136

1,141

1,147

1,156

1,176

1,214

1,232

1,250

1,338

1,360

1,362

1,364

1,370

1,380

1,390

1,396

1,406

1,411

1,431

1,458

1,493

1,499

Provo district

659

674

687

706

723

745

757

768

783

795

823

844

853

864

896

912

921

926

938

947

957

967

977

1,014

1,051

1,071

1,100

1,107

Total

1,731

1,761

1,779

1,811

1,837

1,876

1,893

1,909

1,930

1,951

1,999

2,058

2,085

2,114

2,234

2,272

2,283

2,290

2,308

2,327

2,347

2,363

2,383

2,425

2,482

2,529

2,593

2,606

RESERVOIR CONTROL

UTAH IAEE

Utah Lake is the sole source of water for the Jordan 

Ri\er, and the use of that river for irrigation brought 

up as early as 1867 the question of storing water in the 

lake. The first dam in Jordan River for the purpose of 

holding back the water of the lake was constructed by 

Salt Lake County in 1872 and was destroyed the following year after riparian owners in Utah County 

complained that high water was damaging their lands. 

After several years of argument between the users of 

Jordan River water and the owners of land bordering 

the lake, an arbitration committee, appointed in 1884, 

proposed a compromise agreement which was adopted 

and is still in force. This agreement provided that the 

water of Utah Lake might be held at a height "not to 

exceed 3 feet and 3X inches above the point established 

and recognized as low-water mark [the level at which 

natural outflow ceases]." 2 A monument was then 

erected to mark the level at which water might be held 

without liability for damage, and the compromise level 

was defined by subsequent court decision (Salt Lake 

City v. Colladge 13 Utah, p. 522 (1896),) as "4 feet, 6 

inches below the top of the stone monument at the outlet 

of the lake, which was established by the Utah Lake

' The lake may rise above the compromise level if inflow after reaching that level 

exceeds the rate of natural outflow. Since 1900 the lake level has risen above the 

compromise level in 14 of 47 years, reaching its maximum stage, 3.3 feet above the 

compromise level, in 1922.

commission in 1885." In 1899 a stone obelisk (the 

"Lake Monument") was set about 20 ft southeast of 

this original monument, with a copper bolt set near its 

base and inscribed "5.985 feet above compromise."

Precise leveling to this bench mark shows that the 

monument has settled 0.41 foot in the past 25 years, as 

shown in the following tabulation. In 1946 the Utah 

State Engineer determined by leveling from undisturbed bench marks that the altitude of "compromise 

point" was 4,489.398 feet above sea level. The bench 

mark on the Lake Monument was therefore only 5.57 

feet above the compromise point in 1946.

Elevation of copper bolt "5.985" in Lake Monument

Year

m?,

1934

ICUfi

Agency

U. S. O. S— — — — — — —

U. S. C. & O. S __ — — — -

F, F,

A I

R I

Field engineer

Oliver... _ . __ —

Altitude (feet 

above sea level) 

(1929 Gen. Adj.)

4, 495. 179

4,494.856

4, 494. 769

Utah Lake has an area of about 96,000 acres (150 

square miles) at compromise level. In the period 1900 to 

1948 its surface area has ranged from about 115,000 

acres in 1922 to 23,000 acres "in 1935. At the level 

where natural outflow to the Jordan River ceases, the 

lake area is about 85,000 acres. The lake bed at its 

lowest surveyed point is about 14 feet below compromise 

level, and 45,000 acres of the bed lies more than 10 

feet below the compromise level.

Capacity tables were prepared by the U. S. Bureau 

of Reclamation in February 1935, based upon a datum 

in which the compromise altitude is 4,488.95 feet. 

According to these tables the capacity of the lake when 

the surface is at compromise level is about 850,000 

acre-feet. Prior to 1902 the dead storage in the lake 

was about 550,000 acre-feet, but since that year pumps 

installed at the North Point of the lake have been able 

to lower the lake to a level about 9 feet below compromise level, and the dead storage in the lake is then 

about 140,000 acre-feet. Pumps installed in 1934 at 

Pelican Point near the deepest part of the lake are 

capable of drawing the lake down to a level 12 feet 

below compromise, leaving less than 23,000 acre-feet 

of water in dead storage.

Since 1925 the total diversions from Utah Lake, by 

gravity and pumping, have ranged from 71,600 acrefeet in 1935 to 337,000 acre-feet in 1928, according to 

the annual reports of the Utah Lake and Jordan River 

Water Commissioner. In comparison it was estimated 

by Teele (1903, p. 80) that diversions from the Jordan 

River in 1900, before pumps were installed on Utah 

Lake, amounted to 47,500 acre-feet. The highest 

lake level in that year was more than a foot higher 

than the maximum stage in 1928, when 288,000 acre-
66 LAKE BONNEVILLE

feet was diverted from the river and lake by gravity 

and pumps (see pp. 69-71).

DEER CREEK RESERVOIR

The Deer Creek dam, completed by the U. S. Bureau 

of Keclamation in October 1941, is on the Provo Kiver 

about 16 miles northeast of the city of Provo. It is 

an earth-fill dam with concrete cut-off wall, rising 155 

feet above the stream bed and 235 feet above its rock 

foundation, and has a crest length of 1,300 feet between canyon walls. The reservoir created by this 

dam extends upstream for 6% miles. It has a capacity 

of 152,560 acre-feet between altitudes 5,280 feet 

(bottom of outlet tunnel) and 5,417 feet (top of 20-foot 

radial gates), of which 2,870 acre-feet (below sill of 

trashrack structure at altitude 5,305 feet) is dead 

storage. Storage began in December 1940, and the 

reservoir was first filled to capacity in the period June 

28 to July 3, 1947.

The operation of the reservoir is based on an active 

yield of 100,000 acre-feet annually, leaving 50,000 acrefeet of carry-over storage for dry years. The principal 

subscribers to the project and the proportionate share 

of the active annual storage allocated to each is as 

follows:

Percent 

Metropolitan Water District of Salt Lake (Salt Lake

County)._________________________________ 46. 5

Utah Lake Distributing Co. (for irrigation in Salt Lake

County)_____________-__-_----__-----_________ 15. 2

Metropolitan water districts of five municipalities in

Utah County...__.__________________________ 10. 0

Provo Reservoir Water Users Co. (for irrigation chiefly

in Utah County)-_____-___-__--______--_________ 16. 0

Highland Conservation District (for irrigation in Utah

County)______-___-_____________-___________._____ 5. 0

Provo Bench Canal & Irrigation Co. (for irrigation in

Utah County).______________________________ 2. 0

Pleasant Grove Irrigation Co. (for irrigation in Utah

County)_____-___._._-______-_-_-_-------_-_______ 1. 0

Miscellaneous subscribers for less than 1 percent each

(for irrigation in Wasatch and Utah Counties)_________ 2. 5

Total_-____--____-_-___-______-_-______-____ 98. 2

Generally the flow of the Provo River continues 

through Deer Creek reservoir to satisfy water rights 

downstream and in Utah Lake, but when Utah Lake 

is at high stage, during peak discharge from melting 

snow, some surplus water in that river may be available 

for storage. However, the principal source of supply 

to the reservoir is the Weber River, which has in an 

average year enough surplus above present requirements to supply about 65,000 acre-feet, or two-thirds 

of the annual active yield of the reservoir. The WeberProvo diversion canal, which was enlarged to a capacity 

of 1,000 cfs in 1946, is 9 miles long and conveys the 

surplus and winter power water from tributaries of the

Weber River into the Provo River and thence into 

Deer Creek reservoir. It is planned that ultimately 

the water supply to the reservoir will be further 

augmented by diversion of surplus runoff from the 

North Fork of the Duchesne River, in the Colorado 

River drainage basin.

OTHER RESERVOIRS

The largest reservoir in the northern part of Utah 

Lake valley is that owned by the Geneva Steel Co. 

This reservoir, located in sees. 7 and 8, T. 6 S., R. 2 

E., has a surface area of 312 acres and a capacity of 

2,274 acre-feet. It was constructed on the valley 

plain by excavation of the bottom to form banks as 

high as 12 feet on the north, west, and south sides. 

Water from several sources is collected in this reservoir 

and then is pumped and utilized in various operations 

and returned by gravity. Some water bypasses the 

reservoir after use and empties into Utah Lake. The 

utilization of water by the Geneva Steel Co. is more 

fully described on pages 91-92. It is to be noted 

that the reservoir is essentially an oversized tank for 

industrial operations and does not store flood waters 

for later use.

There are several small lakes and reservoirs in the 

headwaters of the tributaries to the northern part of 

Utah Valley, some of which are used to regulate the 

flow of the streams. The largest of these are six glacial 

lakes on the upper Provo River having a combined 

capacity of about 11,000 acre-feet, from which water 

can be released as needed for irrigation.

FLUCTUATIONS IN WATER SUPPLY

STREAMS

Except for the Provo River, all the perennial streams 

entering the northern part of Utah Valley from the 

east have their headwaters west of the crest of the 

Wasatch Range and drain the steep west slope of that 

range. These streams, in order from north to south, are 

Dry Creek (formed by the junction of Fort Canyon and 

Alpine Creeks), American Fork River, Battle Creek, 

and Grove Creek; and south of the Provo River, Rock 

Creek and Slate Creek. The drainage basins above 

the mouths of the canyons range in area from 60 square 

miles for Amercian Fork River to 5 square miles for 

Battle Creek.

The Provo River heads in the high Grandaddy 

Lake region of the markedly glaciated Uinta Range. 

The drainage basin above the mouth of its canyon 

through the Wasatch Range has an area of about 650 

square miles, of which only about 25 square miles is 

west of the crest of the Wasatch Range. The Provo 

River drainage basin east of the Wasatch Range is more 

than five times as large as the area of the west slope of
GEOLOGt OF NORTHERN UTAH VALLEY, UTAH 67

that range tributary to northern Utah Valley; and it 

ordinarily furnishes twice the quantity of water yielded 

by the tributaries draining the west slope.

RECORDS OF STREAM DISCHARGE

Table 19 lists the available records of the discharge 

of streams tributary to the northern part of Utah Lake 

valley.

TABLE 19.—Stream-discharge records for northern Utah Valley

Qaging station

Dry Creek: 

Alpine Creek near Alpine ...

Fort Canyon Creek at Alpine. 

American Fork: 

North Fork near American 

Fork.

Fork 

American Fork above upAmerican Fork at lower 

power plant.

Battle Creek:

Grove.

Provo River:

Park (above South Fork) .

Provo River above Telluride dam. 

Provo River at canyon 

mouth. 

Provo River at U. P. R. R. 

bridge. 

Provo River at Provo.. ....

Drainage 

basin 

(sq. 

mi.)

15 

6

39 

8

50

60 

5

595

34

630 

650 

670 

675

Period of record

Apr. 1938-Dec. 1940. .. 

Mar. 1938-Dec. 1940. ..

Apr. 1903-Dec. 1905. .. 

Feb. 1912-Sept. 1915...

Jan. 1918-Dec. 1919..-. 

Jan. 1927—-—— —

Mayl900-Dec. 1905.-. 

Apr. 1938-Mar. 1941 ...

Apr.-Sept. 1940. ......

May-Sept. 1941— ——

Oct. 1911-- — .- ——— --

Nov. 1911-—————

Feb. 1905-Dec. 1911 ... 

July 1889-June 1906 _ 

May 1903-Dec. 1904. -.

June 1933-Sept. 1934 ... 

Nov. 1938-... -------

Reference

Utah State Engineer." 

Do.'

USGS.s 

Do. 

Do.

Utah Power & 

Light Co."

Do.3

USGS.2 

Utah State Engineer. 1

Pleasant Grove Irr.

Co.' 

Do.*

USGS.8

Do.2

Do. 2 

Do.2 

Do.»

Do. 2 

Do.2

1 Unpublished records filed at State Capitol and at U. S. Geological Survey 

offices in Salt Lake City, Utah.

2 Published in annual Water-Supply Papers: Surface water supply of United 

States, Part 10, Great Basin. 

' Unpublished records filed in Salt Lake City office of U. S. Geological Survey.

The long-term records for the Provo River and American Fork River show characteristics of flow that aid in 

estimating the annual flow of other ungaged streams 

entering northern Utah Valley. Hydrographs showing 

the monthly discharge of American Fork River and of 

the South Fork of the Provo River are assembled in 

figure 16, together with a graph showing the increase 

of flow in the Provo River between Vivian Park and 

the mouth of the canyon.

The discharge of the South Fork of the Provo River 

commonly reaches two peaks each year, the first in 

May or June because of runoff from melting snow, and 

the second hi October or November. A large proportion of the drainage basin of this stream is underlain 

by cavernous limestones and by far the larger part of 

the annual stream flow is derived from springs in these 

limestones. In figure 16 the part of the discharge that 

is attributed chiefly to the spring freshet is shaded; 

practically all the rest is of ground-water origin, and 

this ground-water discharge reaches a maximum in

247743—53———6

October or November, 6 months later than the melting 

of accumulated winter snow and perhaps more than a 

year later than the precipitation that was the ultimate 

source of the ground water. It is evident from the 

graph that in dry years, such as 1931, 1934, and 1940, 

practically all the stream flow is from ground-water 

sources, and in all years ground water is the source of 

most of the stream flow. Even during the months of 

the spring freshet at least half the flow in the South 

Fork of Provo River is derived from ground water. 

In northern Utah Valley, Battle Creek is the only other 

stream known to be primarily dependent upon ground 

water for the bulk of its flow.

The hydrograph of American Fork River is typical 

of the majority of streams draining the Wasatch Range, 

as well as of most other mountain streams in the intermontane areas of the West. In contrast to the South 

Fork of the Provo River, most of its annual runoff 

occurs during a freshet in May and June, and the 

discharge thereafter decreases until the following 

spring. Only in the driest year, 1934, is there an obvious indication of a secondary peak discharge hi 

October, such as is characteristic of the South Fork 

of the Provo. In several other dry years, however, 

notably 1931, 1939, and 1946, there is a slight increase 

in discharge in the fall, attributed to a seasonal increase 

in ground-water discharge from the limestones that 

crop out in the drainage basin. This hydrograph is 

considered to be representative of the seasonal and 

annual distribution of runoff in Dry Creek, Rock Creek, 

and Slate Creek because the geology, topography, and 

climatology of the several basins are comparable.

The third graph of figure 16 shows the differences 

between the combined monthly discharge of the Provo 

River and South Fork at Vivian Park, and the sum of 

diversions at the mouth of the canyon, measured over 

weirs by the Provo River Water Commissioner for the 

period April 1 to September 30 each year. The 

resulting graph, representing the runoff of the intervening drainage area of about 22 square miles plus 

the arithmetic difference between the subsurface flow 

at Vivian Park and at the mouth of the canyon, is 

subject to a large percentage of error, because a nominal 

error of say, 3 percent in gaging the total flow might 

cause an error of 20 to 30 percent hi the increase in flow 

as obtained by subtraction. Nevertheless, the resulting 

hydrograph for the spring and summer (including the 

period of the annual freshet) agrees closely with the 

hydrograph for American Fork River, which has a 

drainage basin with characteristics similar to the canyon 

section of the Provo River. On the strength of this 

agreement, the gaps in the record during each winter 

have been sketched in with dotted lines, using the American Fork hydrograph as the basis. In some years,
68 LAKE BONNEVILLE

notably 1945 and 1946, the derived runoff from the 

canyon section is markedly less in midyear than might 

be expected; this may result from channel storage in 

the canyon during the freshet, or excessive evapotranspiration losses, or merely the large percentage of error 

that may occur in the computation of runoff by 

differences.

stream flow in South Fork of the Provo River; the 

flow of Grove Creek is based upon a few miscellaneous 

discharge measurements, and statements of residents 

that it is a "smaller" stream than Battle Creek; the 

flow of Dry Creek is based on records for Alpine Creek 

and Fort Canyon Creek for 1938-40, and the assumption that in other years likewise the runoff is about the

1929 | I930| 1931 | 1932 | 1933 | 1934 | 1935 ] 1936 | 1937 [ 1938 | 1939

15.9

1940 | 1941 | I94Z | 1943 | 1944 | 1945 | 1946 | 1947 | 1948

Shaded portions indicate discharge 

attributed to snow melt

AMERICAN FORK RIVER. ABOVE UPPER POWER PLANT

SOUTH FORK OF PROVO RIVER AT VIVIAN PARK

6.0

Dotted lines indicate estimated winter 

discharge, based on analogy with 

American Fork River

V\

: V..

INCREASE IN FLOW OF PROVO RIVER BETWEEN VIVIAN PARK AND MOUTH OF CANYON 

FIGURE 16.—Hydrographs showing discharge of American Fork River and South Fork Provo River, and increase in flow of Provo River below Vivian Park.

ESTIMATES OF SURFACE INFLOW TO NORTHERN UTAH VALLEY

The available records of stream discharge are used 

to derive rough estimates of the total annual surface 

inflow to northern Utah Valley. Estimates have been 

made for each perennial stream for years since 1931, 

as follows: the discharge of American Fork River and 

of Provo River at the mouths of the canyons is computed 

by correlating measured discharge over short periods 

with the long-term records of upstream gaging stations; 

the flow of Battle Creek is obtained from fragmentary 

records in 1945 and 1946, and from analogy with the

same per square mile as in the larger drainage basin of 

American Fork River; discharges of Rock Creek and 

Slate Creek have not been measured, and it has been 

assumed that in those basins the runoff per square 

mile is equivalent to that of American Fork River.

The estimates in table 20 are based on measured discharge which comprises in all years at least two-thirds 

and in some years more than nine-tenths of the total.

Since 1931 the combined flow of the streams draining 

the west slope of the Wasatch Range, including tributaries of the Provo below Vivian Park, has averaged
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 69

TABLE 20.—Estimated surface inflow to northern Utah Valley, 

in thousands of acre-feet

Year

1931—

1932...

1933—

1934—

1936...

1936—

1937—

1938—

1939—

1940—

1941...

1942...

1943...

1944—

1946—

1946—

Dry 

Creek

12

24

19

8

21

27 >26

«25

120

US

23

23

21

23

28

24

American 

Fork

23

65

40

17

44

62

60

«57

>38

>31

50

50

45

51

62

50

Battle 

Creek

2

3

2

2

2

3

4

4

3

3

4

4

3

3

>4

>3

Grove 

Creek

1

3

2

1

3

4

3

3

2

2

3

3

2

3

3

3

Provo 

River

148

294

229

115

220

323

315 •319

1228

1193

•267

1284

1327

1308

1332

>314

Rock 

Creek

6

11

8

3

9

12

12

11

8

6

10

10

9

10

12

10

Slate 

Creek

2

5

4

2

4

6

6

6

4

3

5

5

4

5

6

5

Total

193

395

304

148

303

437

426

425

303

246

362

379

411

403

147

409

Diversions

from other

basins

Weber

River

3

17

ill

13

ill

117

112

16

112

M

19

117

135

158

140

163

Parleys

Creek

3

4

3

4

2

3

4

4

5

5

4

4

2

2

1 Measured; all other quantities estimated, or extrapolated from records obtained 

at stations upstream from mouths of canyons.

about half as much as the flow of the Provo River 

from its drainage basin east of the range, or about onethird of the total surface inflow to northern Utah 

Valley. The total drainage area on the west slope of 

the Wasatch Range is about 110 square miles, less than 

one-fifth of the area of the drainage basin of the Provo 

River above Vivian Park, and it is evident that this 

west slope of the range has a higher yield of water per 

square mile than the Provo drainage basin to the east. 

The computations also indicate that since 1931 the 

Provo River at the mouth of its canyon has discharged 

about 75 percent of the total surface inflow into 

northern Utah Valley, and that its discharge has ranged 

from 72 percent of the total flow in 1935 to 80 percent 

ha 1943. Estimates of the total surface inflow prior to 

1931 are based upon application of this same ratio to 

measurements (in 1890-1908) or computations (for 

1909-30) of the discharge at the mouth of Provo Canyon. According to these estimates the total annual 

surface inflow to northern Utah Valley has ranged from 

about 148,000 acre-feet in 1934 to 735,000 acre-feet in 

1909. The average annual inflow in 55 years of record 

has been 440,000 acre-feet. Between 1930 and 1947 

this rate was exceeded only in 1945, when the runoff 

was about 447,000 acre-feet, but in six other years the 

estimated runoff was close to the long-term average. 

Since 1942 diversions from the Weber River drainage 

basin have contributed 35,000 to 63,000 acre-feet 

annually to the flow of the Provo River as compared 

with a maximum of 17,000 acre-feet in earlier years.

.RESERVOIRS

UTAH LAKE

Utah Lake receives all the water that passes from 

the bordering lowland areas of Utah Valley. From 

northern Utah Valley it receives the water discharged 

directly into the lake by streams, seepage and return

waters from irrigated lands, storm runoff from heavy 

precipitation over the valley area, sewage and industrial wastes, and water that moves underground and is 

then discharged into the lake either along its margins 

or through the sediments of the lake bottom. The 

lake also receives similar discharge from the southern 

part of Utah Valley, which has not been included in 

the study upon which this report is based.

EMPIRICAL DETERMINATIONS OP NATURAL LOSS AND INFLOW

The Utah Lake and Jordan River Water Commissioner, in his annual report (Gardner, reports 1936-47), 

to the State Engineer, includes tables showing monthly 

inflow and outflow of Utah Lake, computed evaporation 

from the lake surface, and total diversion. A summary 

of these data by calendar years is presented in an 

accompanying table (table 21). The net change in 

storage is determined from the lake stages at the end 

of each year, using the capacity tables prepared by 

the Bureau of Reclamation in 1935. (See p. 65.) 

Evaporation is computed by multiplying the average 

surface area of the lake each month by 80 percent of 

the land-pan evaporation as recorded near the outlet 

of the lake. (See table 3.) The measured outflow 

includes the combined flow of the Jordan River, Utah 

and Salt Lake Canal, and East Jordan Canal, as 

measured at the U. S. Geological Survey gaging 

stations at the Narrows (Surface water reports, 1914- 

47), plus the diversions into the Utah Lake Distributing Co. Canal. The computed inflow is equal to the 

algebraic sum of the evaporation, measured outflow, 

and change in storage. The total diversion comprises 

all water taken from the lake or the Jordan River for 

use in Jordan Valley; since 1925 the diversions have 

exceeded the measured outflow from the lake because 

practically all outflow has been used, and ha addition 

there is return flow to the river channel below the 

Narrows, which is diverted to users farther downstream.

The historic relations between precipitation, lake 

levels, computed inflow, and measured outflow of 

Utah Lake are shown graphically in figure 17. These 

graphs show that the maximum stage of the lake since 

records began in 1883 occurred in 1884, when a dam 

was constructed in Jordan River to store water in the 

lake for use in Jordan Valley. The installations of 

pumps at North Point in 1902 and at Pelican Point in 

1934 are reflected in the greater annual range of lakelevel fluctuations subsequent to those years. There 

was natural outflow from the lake in all years prior to 

1931, but from 1931 to 1943 pumps were required for 

all the water that was used from the lake.

The changes in lake levels from year to year reflect 

the meteorologic conditions as shown by the cumulative 

deviation from normal precipitation at Heber. The
1,200 1,000 800 600 400 ZOO

VOLUME. IN THOUSANDS OF ACRE-FEET

UTAH LAKE CAPACITY CURVE

PRECIPITATION

1,000

INFLOW AND OUTFLOW 

FIGURE 17.—Correlation of stages of Utah Lake with precipitation and with inflow and outflow of the lake.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 71

TABLE 21.—Annual changes in storage, inflow, and outflow of

Utah Lake, in thousands of acre-feet 

[From annual reports of the Utah Lake and Jordan River Water Commissioner]

Calendar year

1914. ................

1915.. — - — ---- —

1920. ———— ——— __

1925.-.-----..-.-

1930. - —— — — -.—

1935.---.--.-. ......

1940.-- ----------

1945. —— —— —— ....

1947-- — —— —— --

1

Net change 

in storage

+97.6

-196.8

+107. 6 

+110. 9 

-160.0 

-157. 8 

+328.1

+156.1 

+17.5 

-46.0 

-373. 9 

-66.9

-79.6 

+111.3 

-87.2 

+70.2 

-77.6

-180. 7 

+8.5 

-54.0 

-120.0 

-16.9

+122.3 

+102.3 

+58.0 

-88.7 

-83.1

+100.6 

+22.5 

-11.0 

+98.1 

+174. 3

+42.0 

+131.0

2

Computed 

evaporation

328.7

331.6

327.9 

304.7 

301.2 

338.9

278.1

314.8 

325.1 

397.1 

420.6 

329.4

349.8 

330.1 

343.0 

313.7 

304.5

333.6 

287.6 

289.2 

287.2 

219.7

255.6 

293.1 

298.6 

314.9 

296.1

260.5 

320.5 

316.2 

316.7 

315.7

378.8 

350.0

3

Total outflow

342.8

384.9

312.4 

424.4 

397.4 

311.3 

270.3

489.9 

635.6 

569.0 

480.1 

292.1

266.6 

259.1 

287.9 

260.9 

268.6

189.9 

176.3 

140.3 

92.8 

71.6

150.2 

191.0 

212.5 

220.3 

201.1

172.6 

214.5 

230.1 

199.2 

201.5

245.1 

239.0

4

Computed 

inflow !

769.1

519.7

747.9 

840.0 

538.6 

492.4 

876.5

960.8 

978.2 

920.1 

526.8 

554.6

536.8 

700.5 

543.7 

644.8 

495.5

342.8 

472.4 

375.5 

260.0 

274.4

528.1 

586.4 

569.1 

446.5 

414.1

533.7 

557.5 

535.3 

614.0

665.9 

720.0

5

Total diversion

219.1

258.8

263.4 

216.8 

213.3 

249.5 

256.1

290.2 

296.4 

300.8 

365.8 

314.5

285.4 

303.9 

337.4 

312.0 

310.3

208.3 

188.0 

154.4 

96.6 

78.1

169.3 

213.9 

236.6 

252.6 

232.2

205.4 

250.9 

260.3 

240.1 

94.7 8

295.6 

282.0

1 Sum of columns 1, 2, and 3.

droughts of 1900-5 and 1928-35 (table 1) are indicated 

by downward trends in both graphs, and there is a 

similar parallelism during the periods of excessive 

precipitation, 1906-9 and 1920-22. The long-term 

downward trend in precipitation is reflected by the 

generally lower lake levels in recent years, but those 

lower levels can be ascribed in part to the increased 

proportion of the inflow that has been diverted for 

beneficial use.

The record of outflow shows that in series of years of 

excessive precipitation, the peak runoff has exceeded 

the capacities of existing canals, and surpluses of 

water have wasted into Great Salt Lake. This condition has not occurred in the 25-year period 1925-49, 

and may occur only rarely in the future, for the Deer 

Creek reservoir will be available for storage of surplus 

water in wet cycles.

A significant feature of these graphs is the large 

proportion of the computed inflow that is lost by 

evaporation from this broad but shallow lake. Computed evaporation losses have ranged from 220,000 

acre-feet in 1935 when the computed inflow was 275,000 

acre-feet, to 420,000 acre-feet in 1924 when inflow was 

525,000 acre-feet. In comparison with the water put 

to beneficial use by man, as represented by the total 

diversions, the estimated loss by evaporation is appallingly high. In 1935 the evaporation loss was 

almost three times as great as the beneficial use, and in

all years except 1930 the evaporation has exceeded the 

diversions. The evaporation is least when the area of 

water surface is least, and alternative proposals to 

obtain increased use of water supplies include reduction 

of water-surface area by diking off the shallow portions 

of the lake, and developing deeper or higher reservoirs 

elsewhere in the drainage basin, so that storage in Utah 

Lake may be held to a minimum.

DEFICIENCIES IN BASIC DATA

The data presented in the preceding section show 

that large quantities of water enter Utah Lake and are 

there wasted by evaporation, and also that the computed inflow and outflow of the lake are related to the 

meteorologic conditions. For purposes of quantitative 

determinations of water available for existing rights as 

well as for planning projects for making beneficial use 

of water now being lost by evaporation, these calculated 

data have an obvious weakness: only the measured 

outflow is supported by adequate basic data. The 

computations of evaporation, and hence of total inflow 

which is merely the sum of the measured outflow and 

the evaporation, are derived by use of empirical coefficients. Furthermore, the total inflow as computed by 

this method gives no indication of the proportions that 

are derived respectively from surface flow and subsurface flow.

Evaporation.—The computations of evaporation from 

Utah Lake are based on the assumption that the rate 

of evaporation is 80 percent of the evaporation measured at the standard Weather Bureau land pan at the 

north end of the lake. Although the evaporation from 

open-water surfaces is commonly accepted as more 

nearly 70 percent of the land-pan evaporation, the 

larger figure is justified by its proponents because of the 

shallowness of Utah Lake. For every percentile that 

the empirical constant differs from the true rate of 

evaporation, an error of 3,000 to 5,000 acre-feet in 

total inflow is introduced. It is evident, therefore, that 

detailed study is highly desirable to obtain as accurately 

as possible the true rate of evaporation.

Surface inflow.—The discharge into Utah Lake of its 

two largest tributaries has been measured at the gaging 

stations on the Provo River at Provo and on Spanish 

Fork near Lake Shore. In the years 1939 to 1946 the 

annual flow to the lake from these two streams has 

ranged from 29 to 39 percent of the computed inflow 

to the lake.

The most comprehensive survey of the surface inflow 

to Utah Lake in 1937 to 1940 is that made under the 

direction of S. T. Harding, consulting engineer to the 

Board of Canal Presidents of the Associated Canals. 

This board has kindly permitted study of these records 

during the present investigation of the water resources
72 LAKE BONNEVILLE

of northern Utah Valley. The records show that large 

quantities of water flow into Utah Lake from the 

surface of each of the major alluvial fans bordering the 

northeast part of the lake. The discharge in the natural 

channels of Dry Creek and American Fork River is a 

very small proportion of the total surface discharge 

from the fans of those streams. In dry years the 

discharge of the Provo River into the lake is less than 

that from other sources along the base of the fan between 

Provo Bay and Geneva. These "other" sources of 

surface flow include springs, flowing wells, drains, 

sewers, return flow or waste irrigation water, and local 

precipitation. A comparison between the estimated 

inflow to Utah Valley from tributary canyons and the 

surface discharge into Utah Lake is afforded by the 

accompanying table 22.

TABLE 22.—Surface inflow to and discharge from, in thousands of 

acre-feet, principal alluvial fans of northern Utah Valley

Provo River alluvial fan: 

Inflow:

Rlnto HrpAlr 1

Total. ———————————————

Outflow:

Others*. _ —..._.———————

Total————————— —

American Fork alluvial fan: 

Inflow:

Total.———————— —————

Outflow:

Other 2. _ — ————— ——— ——

Dry Creek alluvial fan: 

Inflow:

Outflow:

Other*....———————————

Total————————— ———

Summary:

1937

315

12

6

333

144.0

96.5

240.5

60

4

3

67

2.2

42.6

44.8

26

.4

6.6

7.0

426

292

1938

319

11

6

336

142.5

101.6

244.1

57

4

3

64

2.5

34.1

36.6

25

.6

17.7

18.3

425

299

1939

228

8

4

240

83.1

85.4

168.5

38

3

2

43

.6

33.5

34 1

20

.2

4.9

5.1

303

208

1940

193

6

3

202

68.2

82.9

151.1

31

3

2

36

.5

25.9

26.4

18

0

6.4

6.4

246

184

i From table 20 on page 69.

* Watson, Gardner, and Harding, 1941, tables 5-8, showing contributions to Utah 

Lake.

The computed inflow to Utah Lake as shown in 

table 21, however, is far larger than the observed inflow 

as measured by Watson, Gardner, and Harding in 

their survey. And, in 1946, the computed inflow of 

666,000 acre-feet was greater by about 130,000 acre-feet 

than the measured inflow to Utah Valley, as recorded 

at gaging stations on the Provo River and South Fork 

at Vivian Park, Spanish Fork at Castilla, American 

Fork River near American Fork, Hobble Creek near 

Springville, Alpine Creek and Fort Creek near Alpine,

Payson Creek near Payson, and Battle Creek near 

Pleasant Grove. If the computed inflow is even 

reasonably accurate, this difference of 130,000 acre-feet, 

plus all the water consumptively used by agricultural 

crops and non-beneficial vegetation throughout the 

valley, must have been derived from unmeasured 

surface and subsurface inflow in tributary canyons and 

from precipitation over the valley.

Subsurface inflow.—In the preceding section it has 

been shown that the computed inflow to Utah Lake is 

greater than the measured inflow to Utah Valley from 

seven streams, of which four are the largest tributaries 

of Utah Lake. It has also been shown that the surface 

inflow to the lake from the fans of three of these tributaries (Provo River, American Fork River, and Dry 

Creek) over a 4-year period was less than 75 percent of 

the water that flowed onto those fans from the tributary 

drainage basin. By far the greater part of the water 

that enters the valley from the tributary canyons seeps 

into the ground, either along the natural channels or in 

irrigation ditches or irrigated tracts. Some of this 

water is then used by plants. Much of it reappears 

at the surface in springs, seeps, wells, or drains at lower 

elevations and then flows to the lake, constituting a 

major fraction of the total surface inflow in the northern 

part of Utah Valley. An unmeasured portion does not 

reappear at the surface but seeps into the lake from the 

underlying sediments. This portion is the subsurface 

inflow.

Springs in the bottom of the lake constitute a source 

of water. A reconnaissance of the lake bed in 1935 

when pumps had reduced the lake area to 23,000 acres, 

leaving three-fourths of the lake bed dry, resulted hi 

location of several spring areas in the western part of 

the lake bed, but the flow from these areas was negligible 

at that tune. Greater yield in subsequent years may 

be inferred because of greater storage in the groundwater reservoir, but it is doubtful that springs constitute a major source of inflow to the lake.

The likelihood of ground-water movement directly 

into the lake, both by underflow hi the post-Provo 

alluvium and by seepage through the Lake Bonneville 

group from underlying artesian aquifers, is discussed 

subsequently (pp. 80, 89). Accurate determinations of 

the quantity of ground-water movement, however, will 

require detailed study of the hydraulic characteristics 

of each aquifer that yields water to the lake. Such a 

determination of the source and amount of subsurface 

inflow is essential for adequate planning for greater 

utilization of the water of Utah Lake. Thus diking off 

certain shallow parts of the lake will serve no practical 

purpose if those shallow parts receive subsurface inflow 

to the extent that there is no reduction in evaporation 

losses.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 73

DEER CREEK RESERVOIR

The Deer Creek reservoir, completed in October 

1940, was first filled to capacity in June 1946. Holdover storage in 1947 and 1948 amounted to at least 

half the capacity of the reservoir. Records of daily 

storage are published annually in Water-Supply Papers 

of the U. S. Geological Survey. For the present study 

the most significant feature of the Deer Creek storage 

is that a large proportion is derived from other drainage 

basins and thus represents a water supply over and 

above that which would be available to the Jordan 

River basin under natural conditions. Strict accounting for all the water that enters or leaves the reservoir 

is essential, because the rights to reservoir storage are 

separate and distinct from those to the natural flow of 

the Provo River.

A question raised recently by the users of water from 

Deer Creek reservoir serves to demonstrate the importance of obtaining adequate basic data before the 

construction of major development projects. At the 

time the dam was constructed, the region was unmapped topographically, geologically, or hydrologically. Recent detailed geologic studies have shown 

that the dam and reservoir rest upon the shattered 

bottom of a huge overthrust block with an essentially 

horizontal fault plane. 3 The problem posed by the 

water users concerns the amount of water loss along 

this fault plane. If there is such loss, it is charged as 

reservoir loss to the Deer Creek water users, and when 

it reenters the Provo River downstream it is not 

discriminated from the "natural" flow of that stream, 

to which other water users have long-established rights. 

It is now known that geologic conditions may permit 

water loss both to the canyon downstream from the

»Baker, A. A., TJ. S. Qeol. Survey. Oil and Gas Inv. Map (in preparation).

dam and to the canyon of South Fork, but available 

hydrologic data are inadequate to show the extent of 

loss. A close determination of the subsurface leakage 

may require draining of the reservoir, which might 

entail serious loss to the water users dependent upon 

the reservoir and its hold-over storage for a permanent 

firm water supply.

WELLiS

DISCHARGE FROM WELLS

The most comprehensive information concerning the 

discharge of wells in Utah Valley was obtained by the 

State Engineer in cooperation with the Works Projects 

Administration in the years 1938 to 1940. Most of 

the wells were visited one or more times each year, 

and the discharge was measured by volumetric methods. 

An estimate was made of the number of days during 

the year that the well discharged, and the annual discharge in acre-feet was computed. The results, tabulated below, show that the total discharge from wells in 

the northern part of Utah Valley ranged from about 

27,000 acre-feet in 1940 to 32,000 acre-feet in 1939.

The vagaries of well operation in Utah Valley limit 

estimates of discharge to rough approximations. 

Some wells flow continuously, others in the irrigation 

season only, some for periods of several days at a time, 

and still others flow intermittently during daylight 

hours. The characteristics of artesian flow introduce 

another variable, for the discharge of most wells is 

greatest when the well is first opened and becomes less 

as the well continues to flow. Under these conditions 

an accurate inventory of ground-water discharge would 

require a meter on every well used. For a modestly 

financed investigation the methods employed in the 

State Engineer's survey offer as good an approximation 

as can be obtained. No data are available for years 

other than those tabulated. (See tables 23 and 24.)

TABLE 23.—Water, in acre-feet, yielded annually by wells in Highland district, 1938-40 

[Based on measurements and estimates by Utah State Engineer]

Section

1938

Irrigation Other Waste Total

1939

Irrigation Other Waste Total

1940

Irrigation Other Waste Total

T. 4 S.. R. 1 E.

25.— ——— — ———— - ..............

26.—————————————————.

32_——————————————————

34.....................................

35...-.-....-.. ........ ...............

36...—— .............................

1

1

1

1

3

11

8

1

1

1

11

8

1

2

I

1

2

8

6

2

1

1

3

8

6

1

2

1

1

2

8

6

2

1

1

3

8

6

T. 5 S., E. 1 W.

1— .......................... .... .....

12.—————— ————— ————— —————

13.—— ——————————— .... ....

14......... .. ..........................

24_ —— —— ——— —— ————— ——— ——

25.....—...... .......................

35—— ...... ...........................

228

201

268

1

1

6

12

1

3

46

1

5 •tno

76

35

40

g

336

289

1

306

87

1

367

553

306

4

1

6

1

2

18

1

1

71

68

2

75

444

629

1

308

24

1

276

374

265

1

6

8

1

2

18

1

78

154

57

79

436

439

1

267

18

1
74 LAKE BONNEVILLE

TABLE 23.—Water, in acre-feet, yielded annually by wells in Highland district, 1938-40—Continued 

[Based on measurements and estimates by Utah State Engineer]

Section

1938

Irrigation Other Waste Total

1939

Irrigation Other Waste Total

1940

Irrigation Other Waste Total

T. 5 S., R. 1 E.

I—.-.——.-.-............-........

3..... ........................... ......

i.. ....................................

5.......... ............................

7.. ...... ............. ....

8.— —— — ———.— . .......... .

^............ ..........................

10...— ................. ........ ......

11.— .................................

12.— ......—. .. ...... ............. ..

IZ... ..................................

\\.... ......................... .......

U........... ..........................

l&......... ............................

VJ..... ................................

18— ..... ........................ ..... ig... ..................................

20... .................................. yi.... .................................

22....... ..............................

2S....... ..............................

2i... ..................................

25.....................................

^/o.. ................................... yj. ....... .............................

29. — . — . — ............. ............

30.—. ................................

35.....................................

36.. ............. ......................

59

238

14

6

67

111

755

280

370

433

648

246

595

150

146

952

486

198

11

12

98

152

1

6

1

3

2

92

11

2

2

6

18

18

126

170

19

4

17

11

38

16

9

1

1

1

2

SA

5

5

54

112

61

59

80

33

47

98

43

53

60

125

168

5

80

137

1

6

1

5

146

240

111

11

6

on

183

993

511

4.45J

517

698

304

R93

231

215

1,021

611

367

17

15

179

291

66

518

168

120

204

81

265

974

267

421

496

835

190

ai n

128

229

1,243

780

181

11

12

196

169

1

6

2

5

3

2

54

12

2

2

6

17

25

105

125

14

2

12

5

1

40

12

9

1

1

1

2

3

89

97

4

255

47

15

15

1

5

6

15

4

24

21

34

1

34

47

1

6

2

5

72

520

ill

12

2

122

210

125

294

1,334

4<?Q

450

513

848

200

ai7

183

245

1,276

801

216

13

12

231

218

43

468

97

92

51

182

896

216

300

495

703

290

833

166

157

1,451

718

156

4

26

76

211

1

6

2

5

3

2

54

35

2

2

6

18

25

105

125

15

2

12

5

1

40

12

9

1

1

1

1

2

4

5

29

9

11

27

14

21

11

31

15

1

6

2

5

46

470

151

127

2

2

6

69

211

1,006

341

344

506

726

322

834

206

169

1,474

739

168

5

27

108

228

T. 5 S., R. 2 E.

1.. ....................................

8— . ....... ...... ...... .............. .

17— ..................................

\^......... ............................

\9......... ............................

-20—— ................................

29.—....— ..........................

30.-— .———„... —— ..............

31 _ ............... _ ................

32 _ --_—.-.-..._.-__.........___.__.

33............ .........................

34—— ................................

Total...........................

76

238

1,214

299

182

410

496

9,644

6

1

7

3

26

10

aQ

6

2

7

837

12

45

1QQ

121

40

216

2,132

6

1

7

114

293

1 flfl9

426

994

633

4.0ft

12,613

54

242

1,241

668

261

904

988

13,326

4

2

5

4

25

1

15

7

2

3

4

596

2

25

152

26

10

26

1,030

4

5

4

81

268

1,408

701

273

933

4

288

14, 952

123

294

1,387

771

291

568

146

12,127

4

2

5

4

25

1

15

7

2

3

4

622

3

12

10

9

35

88

623

4

2

5

4

151

307

1,412

787

328

659

4

146

13,372
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH

TABLE 24.—Water, in acre-feet, yielded annually by wells in Provo district, 1938-40 

[Based on measurements and computions by State Engineer]

75

Section

1938

Irrigation Other Waste Total

1939

Irrigation Other Waste Total

1940

Irrigation Other Waste Total

T. 6 S., R. 2 E.

3.. -

5-. ... . . .

6.. — ....... ..........................

7

8 - - .

9.. ..... _ . .

10- — ................................

16. .

17.....................................

18— ——'--_ — - — .. — . — -._ — .

20——— .................. . ......... ...-

21.— —.—— ..... —...-....-.. ....

24 and 25— .. . — ————— .... .......

27—— ————————..———.—..

28....———— ..——..————.........-.

33._. _.-.... ——.—.———— ........

34.. ...................................

35——————————————————

36. — ————-.„. ———..——..

453 

396 

1,584 

469

14 

1,959 

406 

972 

107

435 

53 

40

1 

30 

37 

23 

32 

7 

43 

18 

110 

7 

14 

25 

46 

7 

33 

4 

78 

8 

25

284 

279 

862 

424

395

507 

1

1 

19

45

1 

767 

712 

2,469 

925 

7 

43 

32 

2,464 

413 

1,493 

133 

46 

7 

469 

76 

163 

8 

25

120 

357 

693 

2,175 

698

i§6

2,512 

2,080

164

830 

138 

60

17 

3 

30 

34 

6 

122 

13 

48 

15

25 

23 

6 

21 

3 

45 

4 

3

9 

160

187 

6

92 

115

5

70 

8 

27

120 

383 

856 

2,392 

738 

6 

122 

143 

2,652 

2,210

194 

23 

6 

921 

149 

132 

4 

3

52 

412 

524 

2,084 

475

74 

1,904 

689 

1, 050 

103

712 

115 

24

1 

18 

10 

30 

34 

6 

100 

13 

100 

5 

10 

25 

25 

6 

21 

3 

45 

4 

3

2 

189 

311

7

188 

4 

53

67

53 

432 

723 

2,425 

516 

6 

100 

87 

2,192 

698 

1,113 

128 

25 

6 

800 

118 

69 

4 

3

T. 6 S., R. 3 E.

19———————————————————

30— ——————————————————

31— - ———————.————.—————

1 

2

1 

2

4 

1

4 

1

4 

1 

2

4 

1 

2

T. 7 S., R. 2 E.

1...—.——........-........-.......

2-..-.. . .- . - . . . .

3

4

5.. . .

9

10. — ———— — — — ——— — —————

11... ——— — . —— . ....... .. — ..- — ..

12 . .

13 ....

14.-... .......

15.. — .......... ......................

161 

250 

700 

33 

178 

65 

349 

674 

9 

130 

33

15 

246 

39 

12 

4 

10 

10 

118 

170 

6 

1

18 

176 

49 

632 

114 

242 

27 

106 

546 

15 

118

33 

583 

338 

1,344 

151 

430 

102 

573 

1,390 

30 

249 

33

10 

130 

320 

1,194 

29 

404 

186 

1,325 

595 

42 

230 

35

24 

229 

39 

17 

13 

15 

16 

76 

144 

5 

30

35 

10 

15 

207 

29 

12 

13 

28 

182 

10 

8

69 

369 

374 

1,418 

71 

431 

215 

1,429 

921 

57 

268 

35

24 

84 

251 

692 

66 

192 

205 

571 

435 

43

38

24 

230 

39 

17 

13 

15 

16 

80 

150 

5 

30

25 

60 

137 

25 

65 

14

40

48 

339 

350 

846 

104 

272 

235 

651 

625 

48 

30 

38

T. 7 S., R. 3 E.

6——— —— ——— ——— ———— —— ————

7... —.-. —— ——— ...... -—.——..

17 .. .

18.... —— .............................

15

8

31

2 

3 

229

1

7 

4 

2

18 

18 

233 

33

12 

1 

1

3

19

255 

3

3

20

15 

23 

256 

23

12

1 

16

3

20 

260

6

15 

20 

261 

22
76 LAKE BONNEVILLE

THOUSANDS OF ACRE-FEET W O4k - 

O C3 

/

/

/

/

/

- —— — —— - — —

X~"--- /

/

~—~~^,^^

^\— , . ., .-^ ^r-*^ 

^.,,

ANNUAL DISCHARGE OF AMERICAN FORK RIVER NEAR AMERICAN FORK

AMERICAN FORK D.R.A. WELL (D-5-1) 14 odb-1 

Fluctuations due primarily to recharge

30

JACOB COX WELL (D-5-0 20 aba-2 IN LEH! 

Fluctuations due primarily to irrigation draft

30

J

10

PROVO D.R.A. WELL (D-7-2) 12 bcb-l 

Fluctuations due primarily to municipal draft

GENEVA STEEL WELL (D-6-2) 8 dbd-2 

Fluctuations due primarily to industrial draft

MONTHLY RAINFALL AT PROVO

1935 1936 1937 1938 I939I940I94I 1942 1943 1944 1945 1946 1947

FIGUKE 18.—Hydrographs of four wells in northern Utah Valley.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 77

FLUCTUATIONS OF WATEK LEVEL AND ARTESIAN PEESSUEE

The quantity of water stored in a ground-water 

reservoir varies from day to day, from season to season, 

and from year to year in response to changes in the 

rate at which water is taken into or discharged from 

the reservoir. The water level in wells—or the shut-in 

artesian pressure in flowing wells—fluctuates in response 

to these changing conditions. The artesian pressure is 

a major factor controlling the rate at which a flowing 

well can yield water. Determination of the fluctuations 

in water level and artesian pressure in wells and their 

causes is therefore essential to understanding the 

capabilities of the reservoir as a source of water supply. 

The types of fluctuations observed in wells in northern 

Utah Valley are discussed briefly below. A more 

detailed discussion of fluctuations in a part of the area 

has already been published. (Taylor and Thomas,

1939. pp. 120-135).

SEASONAL FLUCTUATIONS

Fluctuations of water level have been recorded by 

gages installed on four wells in northern Utah Valley 

for periods of 5 years or more. Hydrographs for these 

wells, presented in figure 17, show seasonal and annual 

fluctuations that are typical of wells in the area.

The American Fork Drought Relief Administration 

well is located near the north edge of the town of 

American Fork. Although there are shallow wells 

higher on the American Fork alluvial fan, this is the 

highest well that reaches the pre-Lake Bonneville 

deposits which constitute the productive aquifers in 

the area of artesian flow to the south and west. The 

fluctuations of water level in this well are closely related 

to the discharge of American Fork River. In most 

years the water level rises sharply in May and June 

during the annual freshet. These are the periods of 

greatest recharge to the ground-water reservoir, and 

this well is in an area where the effects of such recharge 

are pronounced. In the comparatively dry years 1939,

1940. and 1943, the stream runoff was low and recharge 

to the ground-water reservoir was at a minimum.

The other three wells are in the area of artesian flow, 

and the principal fluctuations of artesian pressure are 

caused by operation of flowing wells. There is, of 

course, no flow from the observation wells, which are 

equipped with pressure recorders, and the fluctuations 

therefore result from operation of other wells in the 

vicinity. The Jacob Cox well is in the midst of an area 

where many wells are used for irrigation; heavy draft 

on these wells during the irrigation season results in a 

decline of 10 to 20 feet in the pressure head of the 

observation well. The Provo Drought Relief Administration well is in the western part of Provo City 

where many residents have small artesian wells for

domestic use: the wells are operated intermittently 

throughout the year, but the heavier draft for lawns 

and gardens in the summer commonly causes some 

seasonal decline of pressure in the observation well. 

The Geneva Steel Co. well is near the center of the 

plant area, and the only wells within half a mile are 

those used by the company for industrial purposes; 

this draft, though intermittent, is distributed throughout the year, and there is no pronounced seasonal cycle 

to the fluctuations in the observation well.

LONG-TERM FLUCTUATIONS

The close relation between water levels in wells in 

the recharge area and the discharge of streams is 

typified by the uppermost graphs of figure 18. The 

general trend of the other hydrographs also reflects 

the trend in stream discharge, even though the 

dominant fluctuations result from operation of 

nearby wells. In general throughout the area, the 

discharge from artesian wells is minimum during the 

winter, and the graphs of figure 18 indicate that water 

levels are fairly stable at the end of each year. The 

month of December has therefore been selected for 

measurements in numerous observation wells throughout the valley. Hydrographs based on annual measurements in artesian wells (fig. 19) show a remarkable

FIGURE 19.—Hydrograpbs of 17 wells tbat tap artesian aquifers of Fleistocens 

pre-Lake Bonneville deposits.
78 LAKE BONNEVILLE

degree of uniformity in trend, and it is likely that these 

changes in water level may be indicative of changes in 

storage in a common reservoir. These graphs, and 

table 25, summarizing the changes recorded in the 

same wells, show a general upward trend in water 

levels since 1935, which marked the end of a severe 

drought cycle in Utah. However, the water levels in 

all wells declined during the dry years 1939, 1940, and 

1943, and the graphs thus show a close relation to the 

meteorologic conditions in the drainage basin and to 

the runoff in streams that enter northern Utah Valley.

TABLE 25.—Changes of water levels in observation wells

Year

1936... ._._.__.

1937— __--____

1938— ________

1939.... ___.._.

1940— -------

1941_._. _______

1942— ________

1943..-.. ......

1944... ________

1945— _----___

1946_________-_

1947— -____--_

Net change during year, in 

feet

Average of 

12 wells in 

Highland district

+ 5.4 

+ 4.5 

+ 1.6 

-3.8 

-3.0

+ 6.5 

-.3 

-2.7 

+ 1.6

+ 4. 5

-1.4 

+ 1.3

Average of 

5 wells in 

Provo district

+ 4.8 

+ 2.2 

-.3 

-1.3 

-1.8

+ 4.0 -.5 

-.9

+.9 

+ 3.4

— 1. 1

+ 1.2

Cumulative change since 193S, 

in feet

Average of 

12 wells in 

Highland district

+ 5.4 

+ 9.9 

+ 11.5

+ 7.7 

+ 4.7

+ 11. 2 

+ 10. 9 

+ 8. 2 

+ 9. 8 

+ 14.3

+ 12.9 

+ 14. 2

Average of 

5 wells in 

Provo district

+ 4.8 

+ 7.0

+ 6. 7 

+ 5.4 

+ 3. 6

+ 7. 6 

+ 7.1 

+ 6.2 

+ 7. 1 

+ 10.5

+ 9.4 

+ 10.6

RELATION BETWEEN FLUCTUATIONS OF WATER LEVEL AND TOTAL 

WELL DISCHARGE

The owners of wells drawing from several of the 

artesian reservoirs of Utah have a fairly regular irrigation routine, opening the wells for about the same 

period year after year. In these areas the total well 

discharge correlates fairly well with the artesian pressure as recorded in selected wells, just as discharge 

from an artesian spring is commonly- an indication of 

the pressure that produces the discharge. The total 

discharge from wells in such areas is greatest during 

years when artesian pressure is highest, and hence 

during years of greater-than-normal precipitation, 

runoff, and ground-water recharge.

A different relationship is observed in areas where 

wells are pumped for irrigation, or where they are used 

chiefly to supplement surface-water supplies. In these 

areas the total discharge from wells is generally greatest 

during dry years and when the stream flow is less than 

normal. In those years the water levels in wells are 

commonly lower than in wet years because of reduced 

recharge. The total discharge thus may increase 

concurrently with declining water levels, owing to 

operation of a greater number of wells for a longer 

season.

In the northern part of Utah Valley many wells are 

used to supplement surface-water supplies and in a 

wet year may be opened for only a very short period. 

Other wells constitute the sole source of irrigation water, 

and are used throughout every irrigation season. It 

might be expected that no clear relationship between 

total well discharge and average water levels in observation wells would be observed under these varying 

conditions. During the 3 years for which estimates of 

total well discharge have been made this lack of correlation is evident. In 1939 the discharge from wells was 

about 4,000 acre-feet more than in 1938, although water 

levels that year had declined an average of 2^ feet in 

observation wells. In 1940 the total discharge from 

wells was slightly greater than in 1938 and more than 

3,000 acre-feet less than in 1939; the water levels in 

observation wells were about 5 feet lower in 1940 than 

in 1938.

It is obvious that for a determination of the quantities of ground water actually used each year there is 

at present no substitute for a complete inventory 

based on actual measurements of the discharge from 

each well.

SPRINGS AND DRAINS

Springs are the points or areas of natural discharge 

of ground water from the water-bearing rock materials, 

and "drains" carry discharge from seepage areas or 

areas where the water table is close to the surface. 

Many of these drains—whether tunnels or pipes— 

doubtless were constructed in order to make soggy 

lands arable, but in an area where water is scarce the 

water developed by the drains is valuable. Many 

drains serve principally as producers of water, and are 

not greatly different from "developed springs." There 

are scores of springs and drains in northern Utah 

Valley that are put to beneficial use for irrigation, stock 

watering, or industrial purposes; and also many spring 

and seep areas in the lowlands bordering Utah Lake, 

some large enough to discharge water seasonally or 

continuously into the lake and some forming swampy 

areas of large evapotranspiration losses.

Springs along the toe of the Orem bench discharge 

ground water from the sand and gravel of the Provo 

formation. The developed springs used by Geneva 

Steel Co. are examples: The Fugal Springs increase in 

discharge throughout the irrigation season, reaching a 

peak of more than 5 cfs in October or November, then 

decline gradually to a minimum of 2 to 3 cfs in the 

spring. Water applied for irrigation on the Orem 

bench is the source of a considerable part of this spring 

discharge, and no doubt many springs have originated, 

and all have increased in flow, since irrigation began 

more than 80 years ago.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 79

Most of the springs in the northern Utah Valley, 

including several of large flow, are in the lowlands 

bordering the east and north shores of Utah Lake. 

The belt in which the springs occur ranges in width 

from half a mile, west of Provo, to more than a mile 

near Lehi. The highest springs are as much as 30 

feet above the compromise level of the lake; there are 

many close to the compromise level, and also some that 

discharge from the lake bed when the lake is at low 

level. Generally these springs rise where the clay 

member of the Provo formation is at the surface. 

Some discharge water that has moved through the 

coarser shore facies of the Provo formation. In large 

part, however, these springs discharge water that has

1500

1000

1500

1000

500

500

SOURCES OP GROUND WATER

Practically all the ground water used in northern 

Utah Valley, whether from wells or springs, is derived 

from unconsolidated materials of the valley fill, of 

Quaternary and possibly Tertiary age. Small supplies 

of water are also obtained from springs and tunnels 

along the base of the Wasatch Range, where the water is 

yielded by consolidated rocks; these sources are relatively unimportant to the economy of the valley, however, and are not included in the following discussion.

Some of the water-bearing formations appear at the 

surface, and their areas of outcrop are shown on the 

geologic map (pi. 1). The post-Provo alluvial deposits 

and the sand and gravel members of the Provo formation

1940

BULL PASTURE DRAIN 

FIGURE 20.—Monthly discharge from three spring areas in northern Utah Valley, 1937-40.

moved upward through this clay from the underlying 

pre-Lake Bonneville deposits in which the water is 

under artesian pressure (see p. 85).

Hydrographs of the discharge from three spring 

areas are presented in figure 20. The spring flow from 

each area is least during the irrigation season (June to 

October), when artesian pressure in the pre-Lake 

Bonneville aquifers is least because of the discharge 

from flowing irrigation wells.

Saratoga Springs, along the northwest shore of Utah 

Lake and three-quarters of a mile south of the outlet to 

Jordan River, are warm springs. The swimming pools 

at the resort require more water than is discharged 

naturally by the springs, and several wells have been 

drilled in the vicinity, which discharge water by artesian 

pressure and at a temperature of about 110° F. It is 

likely that this water rises from considerable depth, 

possibly along faults that may extend south along the 

base of the Lake Mountains.

probably bear some water throughout their areas of 

outcrop. Several wells have been dug or drilled in 

these deposits and yield water for domestic and stock 

use and for a small amount of irrigation. However, the 

most important water-bearing deposits in northern 

Utah Valley—the pre-Lake Bonneville deposits—do 

not appear at the surface except in a small area near 

Pleasant Grove. These deposits are known chiefly 

from well logs. Section F-F' on plate 4 is a geologic 

section based on well logs, extending along a line parallel 

to the front of the Wasatch Range from Lehi to Provo. 

The formations penetrated by wells along this profile 

include the post-Provo alluvial deposits, the Lake 

Bonneville group, the pre-Lake Bonneville deposits, 

and possibly Tertiary deposits.

POST-PROVO ALLUVIAL DEPOSITS

The post-Provo alluvial deposits form the channel 

beds and flood plains of the present streams, and have
80 LAKE BONNEVILLE

their greatest extent and thickness along Provo River, 

American Fork River, and Dry Creek. At the mouths 

of the respective canyons these post-Provo deposits 

consist predominantly of well-rounded but poorly 

sorted gravel and boulders. Downstream the average 

size of materials becomes generally smaller, but there 

is a considerable amount of gravel as far as the towns 

of Provo, American Fork, and Lehi. Below these towns 

the proportion of sand and silt increases. As shown in 

logs of wells near American Fork (sec. F-F', pi. 4), the 

alluvial material may be as much as 40 feet thick.

WATER TABLE

Water is generally within 25 feet of the surface in the 

coarse post-Provo alluvium, and is not confined. The 

few wells on the flood plains of American Fork and 

Provo Rivers indicate that the water table has a gradient 

approximately equivalent to that of the stream. There 

are too few wells, however, to provide details as to the 

form of the water table. It is certain that this form has 

been modified considerably from natural conditions by 

the irrigation of fields and by seepage from canals and 

ditches in the flood plain.

RECHARGE AREA

Water enters the alluvium by seepage from the 

natural channels of the streams or from unlined canals 

or ditches that divert the stream water across the flood 

plain. Some water in the alluvium may also be derived 

by infiltration of precipitation or from water applied for 

irrigation on the flood plain. Finally, irrigation on the 

Orem and Highland benches has caused the water table 

in those areas to rise until in some areas it is higher 

than that under the flood plains of the stream. In 

those areas some ground water will move from under 

the benchlands toward the alluvium along the streams. 

Thus the recharge area for the ground water in the 

alluvium includes the area of the stream channels and 

flood plains as well as the borders of those flood plains. 

Most of the water, however, comes by one means or 

another from the stream that deposited the alluvial 

materials.

MOVEMENT AND NATURAL DISPOSAL

The ground water in the alluvium moves toward 

Utah Lake. At the mouths of the stream canyons 

where the post-Provo alluvium is coarse-textured and 

permeable, it is likely that underlying and older formations are similarly permeable, and that water may 

enter those formations from the alluvium. Farther 

from the mountains, the post-Provo deposits in many 

places rest upon finer-textured materials, and probably 

there is little loss by downward percolation from the 

alluvium into older sediments in those reaches. Downstream from the towns of Provo, American Fork, and

Lehi, where pre-Lake Bonneville aquifers contain 

water under artesian pressure, the alluvium may 

receive water by slow upward movement through the 

confining layers above those aquifers.

The ground water in the alluvium eventually discharges into Utah Lake or into the streams that flow 

to the lake, and thus it is very closely related to the 

water in the stream: it enters the valley at the mouth 

of the same canyon, follows the same general course 

and eventually reaches the same destination—but 

makes its way at a much slower rate. Not all the 

ground water in the alluvium reaches the lake, however, 

for it may be evaporated in the areas where it is close 

to the surface. Also, under most of the flood plain, 

ground water is within reach of trees and other waterloving vegetation, and a considerable quantity is discharged by transpiration. Because of the close relation 

between the surface water and the ground water in the 

alluvium, this evapotranspiration withdrawal may be 

replenished by seepage from the stream, resulting in a 

net loss in stream flow.

CONSUMPTIVE USE

Beneficial consumptive use of water in the alluvium 

includes the negligible quantities of water that are 

drawn from wells for domestic and stock use, and the 

quantities taken by subirrigation of such cultivated 

crops as alfalfa in areas where the water table is close 

to the surface. By comparison the nonbeneficial 

consumptive "use" by native vegetation is doubtless a 

larger quantity. It is not possible to eliminate this 

nonbeneficial withdrawal, however, as long as the 

present stream channels and irrigation canals are used 

as conduits for appropriated water, because any lowering of the water table in the flood plain would result 

in infiltration and seepage losses from those conduits.

THE PROBLEM OF POLLUTION

Three of the largest towns—Provo, American Fork, 

and Lehi—have identical geological settings. Each is 

located on a post-Provo alluvial fan that is underlain 

by the silt or clay members of the Provo formation. 

These fans have a maximum thickness of about 

50 feet; the average thickness is much less. Ground 

water that evidently represents the underflow from 

the streams at the towns moves along the base of 

these fans and emerges in seeps at the thinned edges 

of the fans. The village of Alpine is on a gravelly 

flood-plain deposit that overlies impermeable beds in 

the Alpine formation. The underflow of Dry Creek 

and Fort Canyon Creek moves along the base of the 

flood-plain deposit and emerges downstream along 

Dry Creek.

Pleasant Grove is located on a pre-Lake Bonneville 

fanglomerate on which are preserved local remnants of
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 81

the younger and less permeable Lake Bonneville deposits. The depth to impermeable layers and ground 

water is considerably greater at Pleasant Grove than 

at the other towns.

At each of the towns and in much of the surrounding 

area the ground is generally favorable for the construction of cesspools and equally favorable for pollution of the shallow ground water. It should be noted, 

however, that each of the towns has a municipal water 

system that delivers potable water from other sources, 

and Provo has a sewer system that carries the city 

wastes to Utah Lake.

Dr. V. P. Sokoloff collected numerous samples of the 

waters at various places in the valley and tested them 

for the presence of nitrite which, like nitrate, is associated with organic decomposition. The tests were 

made by adding griess reagent (solution containing 

0.2 gram of alpha naphthyl amine, 2.0 grams of sulfanilic acid, 20 grams of tartaric acid, in about 9 ounces 

of water) to samples of clear water. Nitrite was inferred to be present if the solution turned pink within a 

few minutes. Positive tests were obtained rather 

generally from a few dozen samples of the surface 

waters. Numerous seeps were tested where the water 

issued from the ground and many of these gave positive 

tests. No tests were made to determine the presence 

of harmful bacteria, and it is known that the inorganic 

products of decomposition persist under conditions 

that do not support bacterial life. Nevertheless, 

these tests strongly suggest that the shallow ground 

water in many places has been polluted.

T;AKTi BONNEVILUB GROUP

The water-bearing properties of the Lake Bonneville 

group vary widely, depending upon the topographic 

position and the permeability of the materials. Coarse 

and permeable materials of the Bonneville formation 

and of the glacial outwash and moraines absorb water 

readily from precipitation, but are generally entirely 

above the regional water table and are therefore not 

saturated. The clay and silt deposits in the Alpine 

and Provo formations in the lower parts of the valley 

are largely saturated with water, but their permeability 

is generally so low that this water is not yielded readily 

to wells. The clay beds constitute the confining 

layers over the pre-Lake Bonneville aquifers, in which 

water is under artesian pressure. Although the clay 

is relatively impermeable it is not absolutely so, and it 

is probable that in the aggregate, large quantities of 

water move upward from the underlying aquifers and 

are discharged into Utah Lake by seepage or by evapotranspiration at the land surface.

The principal aquifers in the Lake Bonneville group 

are the gravel and sand members of the Provo and

Alpine formations. These members are most extensive 

under the Orem bench and under the Highland bench.

WATER TABLE

As shown by measurements in about 40 wells, the 

water table is generally less than 50 feet below the 

land surface in the wells that have been dug or drilled 

into the Provo and Alpine formations. The water 

table slopes generally in the same direction as the land 

surface, at a rate of 60 to 80 feet per mile. (See pi. 3.) 

Near the eastern border of the Orem bench the water 

table is from 40 to 70 feet higher than under the adjacent flood plain of the Provo River.

> RECHARGE AREA

The ground water in the gravel and sand members of 

the Provo and Alpine formations is derived chiefly 

from excess irrigation water applied on the Orem and 

Highland benches. Precipitation upon those benches, 

especially winter precipitation, doubtless contributes 

also to the ground water. Thus the recharge area is 

approximately coextensive with the outcrops of those 

formations, and extends over the entire benchland 

area.

Before the beginning of irrigation on the benches 

some 80 years ago, the water table was considerably 

lower than it is today, as indicated by the records of 

depths at which water was encountered in early wells 

(Richardson, 1906, pp. 50-51). At that time the 

water table under the benches may well have been 

lower than that under the flood plains of the Provo 

River and American Fork River, and it is likely that 

water moved from these flood-plain materials into the 

sand and gravel members of the Provo and Alpine 

formations.

MOVEMENT AND NATURAL DISPOSAL

The ground water under the Orem and Highland 

benches moves generally southwestward, roughly parallel to the slope of the land surface and at right angles 

to the contours of the water table as depicted in plate 

3. Some water along the eastern edge of the Orem 

bench doubtless moves eastward into the alluvium of 

the Provo River flood plain. Most of the water is 

discharged by springs and seeps along the edges of the 

benches, but some may continue underground in sandy 

beds of the Lake Bonneville group west of those benches 

and ultimately be discharged from seeps near the margin 

of or in the bed of Utah Lake.

CONSUMPTIVE USE

A few domestic wells still obtain water from the 

gravel and sand members of the Provo and Alpine 

formations. Several others have been abandoned since 

the installation of community water-supply systems. A 

few irrigation wells have been dug or drilled into these
82 LAKE BONNEVILLE

beds, some east of American Fork and others in the 

northern part of Orem. Most of these wells are used to 

supplement surface-water supplies and are therefore 

pumped only in dry years, and then only for a few days 

to a time. Some apparently have not been used for 

several years. The aggregate quantity of water 

pumped from all wells is small. Doubtless the greatest 

use of water from these formations has been by development of springs and drains along the outer edge of 

the Orem bench. (See p. 78.)

PRE-LAKE BONNEVILLE PLEISTOCENE DEPOSITS

The pre-Lake Bonneville Pleistocene deposits are 

exposed in a small area east of Pleasant Grove. (See 

pp. 14-17.) Elsewhere they are buried under the 

Lake Bonneville group, and their characteristics are 

known chiefly from the information that can be gleaned 

from well logs. These logs reveal that the pre-Lake 

Bonneville Pleistocene deposits probably underlie the 

entire valley, including Utah Lake as well as the land 

areas as far east as the base of the Wasatch Range. 

Few wells have penetrated the entire thickness of these 

deposits: the logs of the deep wells of the Geneva 

Steel Co. indicate a thickness of about 400 feet at 

Geneva, but near Lehi the pre-Lake Bonneville 

Pleistocene deposits may be only 150 or 200 feet thick, 

judging by the log of the railroad well (D-5-1) 5caa-2 

at Cutler Junction. (See p. 13 and pi. 4, sec. F-Ff .)

Several geologic sections show the character of the 

buried pre-Lake Bonneville sediments in northern Utah 

Valley. Three of these sections are approximately 

perpendicular to the trend of the Wasatch Range, 

and show the gradation of sediments from the mountain 

front toward the central part of the valley. In section 

A-A' of plate 4, boulders, gravel, and sand predominate 

in the northeasternmost well. Tongues of these 

coarse materials can be recognized as far as 5 miles to 

the southwest, becoming progressively thinner, and 

separated by increasing thicknesses of fine-grained 

materials. The gravel and boulder deposits thicken 

northeastward toward the base of the mountains. 

The uppermost beds have a valleyward gradient of 

about 50 feet per mile, decreasing toward the valley. 

Two sections across the Orem bench (pi. 4, sees. B-B' 

and (7-0") show similarly the general westward gradient 

of the pre-Lake Bonneville Pleistocene deposits, but 

there are too few wells to show the gradation from 

coarse to fine sediments with increasing distance from 

the mountains.

The curving geologic sections of plate 4 (D-D' and 

E-E'} show the gradation of materials from the axis 

of the American Fork alluvial fan. The coarse upper 

beds of the pre-Lake Bonneville deposits, constituting 

the shallow artesian aquifer, have an average thickness

of 75 to 100 feet under the 4,570-foot contour, and 

about 50 feet under the 4,500-foot contour. This 

aquifer is thicker toward the eastern end of the sections, 

which is closer to the mountain front and near the 

area of outcrop of the pre-Lake Bonneville Pleistocene 

deposits.

The geologic section from Lehi to Provo (F-Ff) is 

along a line roughly parallel to the base of the Wasatch 

Range, and crosses the alluvial fans of Dry Creek, 

American Fork River, and Provo River. Both the 

Lake Bonneville group and the underlying Pleistocene 

deposits are thinnest toward the north end of this 

section, where they probably rest on the buried flank 

of the Traverse Mountains. The central part of Utah 

Valley, represented by the southern part of section 

F-F' of plate 4, was evidently deeper and lower 

throughout the Pleistocene, and both the Lake Bonneville group and the pre-Lake Bonneville deposits are 

thickest there. The pre-Lake Bonneville sediments 

are thicker where the section skirts the Highland 

bench (between Lehi and American Fork) and the 

Orem bench (between Geneva and Lakeview) than in 

the intervening areas. This increased thickness results chiefly from the greater amount of coarse sediments opposite the mouths of the principal canyons.

Throughout the area where wells have been drilled, 

the pre-Lake Bonneville Pleistocene deposits consist of 

four major units. The upper unit, upon which Lake 

Bonneville was formed, is predominantly coarse mate- 

.rial, poorly sorted but relatively permeable, with some 

beds of clay and silt. Water in this unit has an artesian 

pressure sufficient to produce flowing wells in the vicinity of Lehi, American Fork, Geneva, and Provo; the 

unit is here called the "shallow Pleistocene artesian 

aquifer." The aquifer is from 75 to 100 feet thick near 

American Fork and Geneva, about 50 feet thick near 

Lehi and Provo, and thinner farther west where the 

water-bearing materials are predominantly sand. There 

is an increasing proportion of fine-textured materials to 

the west in this uppermost zone, and, in consequence, 

wells may obtain water from thin gravel tongues at 

various depths. These thin beds are designated separate "aquifers" by local usage; there may be a slight 

difference in artesian pressure of the individual beds, 

and no evidence of interference between wells of slightly 

different depths. In general, however, the hydrologic 

characteristics of the entire zone are fairly uniform, and 

quite distinct from those of deeper water-bearing zones.

Beneath the shallow Pleistocene artesian aquifer 

there is a unit of predominantly fine-textured material, 

commonly 50 to 75 feet thick. In logs of the wells of 

the Geneva Steel plant (fig. 5) this unit is about 90 

feet thick and consists of an upper and lower unit of 

clay separated by about 30 feet of gravel. The fine-
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 83

textured material may be silty or even sandy near the 

mountains, but under most of the valley it is made up 

of blue clay-sized particles, similar to those of the lakebottom sediments of Lake Bonneville and inferred to 

be, similarly, of lacustrine origin. The materials are 

dominantly calcium carbonate, and are evidently a 

"rock flour" derived from the limestone formations of 

the tributary drainage basin.

The deep Pleistocene artesian aquifer underlies this 

lake clay and, judging by well logs, is ordinarily 75 to 

150 feet thick. Its top is commonly more than 200 

feet beneath the land surface, but near Lehi it is less 

than 150 feet below the surface owing to the thinning 

of all sediments along the flank of the Traverse 

Mountains.

Beneath the deep Pleistocene artesian aquifer is 

another zone of lacustrine clay, encountered hi the 

deepest well of the Geneva Steel Co. between depths of 

420 and 490 feet. No similar lake clays were penetrated 

in the lower 340 feet of this well. There were therefore 

at least three and perhaps four periods during which 

the valley was occupied by a lake, the last of which 

was Lake Bonneville; these three or four periods were 

separated by intervening periods during which the 

streams deposited alluvial materials over the valley 

floor. These alluvial materials include the coarse, 

permeable zones which supply nearly all the water 

yielded by wells in the valley.

SHALLOW PLEISTOCENE ARTESIAN AQUIFER

When wells are drilled through the Lake Bonneville 

group and into the shallow artesian aquifer of the preLake Bonneville deposits, the water rises above the top 

of that aquifer, and in the great majority of wells drilled 

to date it has risen high enough to flow at the land 

surface. This upward pressure exists because the 

overlying Lake Bonneville group is relatively impermeable and confines most of the water within the aquifer. 

The aquifer is saturated at all times beneath this confining layer. Nevertheless there is movement of water 

within the aquifer from places of high hydrostatic head 

toward places of lower head.

PIEZOMETKIC SURFACE

If the casings of all wells were extended high enough 

to prevent flow from the wells, the level to which water 

would rise hi each well represents a point on the artesianpressure surface or piezometric surface of the aquifer. 

The form of this piezometric surface varies from day to 

day, from season to season, and from year to year, in 

response to the rates at which water is recharged into 

or discharged from the aquifer. A flowing well creates 

a depression hi this pressure surface, toward which 

water moves as long as the well continues to flow. For

this reason, the form of the piezometric surface under 

natural conditions can best be determined when discharge from wells is at a minimum.

In April 1947, prior to the irrigation season, measurements were made of the water level in nonflowing wells 

and of the shut-in pressure of flowing wells. The 

piezometric surface of the shallow artesian aquifer, 

constructed on the basis of measurements hi about 120 

wells, is shown on plate 3. The area of artesian flow, 

in the central and lowest parts of the valley, is the area 

in which the piezometric surface is higher than the 

land surface.

In general, the piezometric surface is lowest near 

Utah Lake, and rises to the east and north with an 

average gradient somewhat less than that of the land 

surface. The piezometric surface does not conform in 

detail with the topographic surface, however. It is 

flattest under the Highland and Orem benches, where 

the gradient is commonly only from 10 to 20 feet per 

mile in the coarse sediments opposite the mouths of the 

larger canyons. It is steepest near the shore of Utah 

Lake, where the gradient may exceed 40 feet per mile. 

This higher gradient may be indicative of lesser permeability and generally finer texture of the aquifer at 

greater distance from the mountains.

The piezometric surface has the form of a series of 

sloping ridges and intervening embayments. The 

ridges follow the axes of the alluvial fans of Dry Creek 

and American Fork River and there are two opposite 

the mouth of Provo Canyon, one at the city and one 

extending west under Provo bench. The embayment 

of the piezometric surface between Lehi and American 

Fork may have been caused by the discharge from 

springs at the Lehi Sugar Factory. The embayment 

along the toe of the Provo bench and the steep gradient 

to the west are probably indicative of spring discharge 

from the shallow artesian aquifer into Powell Slough.

The direction of movement of water in the shallow 

artesian aquifer is at right angles to the contours drawn 

on plate 3. These contours show that water moves 

down the axis of each of the principal streams, and also 

outward from these axes. The westward slope of the 

piezometric surface continues past the areas where large 

quantities of water are taken from wells, and on to the 

westernmost wells, along the shore of Utah Lake. Thus 

it is clear that this gradient has not resulted from well 

discharge but is a product of natural conditions under 

which there has been discharge from the aquifer ia the 

central and lowest part of the valley (under Utah Lake) 

for a long period of time.

CONSUMPTIVE USE

The shallow artesian aquifer is the source of most of 

the water yielded by wells in northern Utah Valley.
84 LAKE BONNEVILLE

More than 80 percent of the wells are less than 200 feet 

deep, and most of these tap the shallow artesian aquifer. 

In the vicinity of Lehi, however, that aquifer is within 

50 to 100 feet of the surface, and is no longer an important producer. Most of the early wells bored to 

this aquifer have long since ceased to flow, and therefore near Lehi the majority of productive wells today 

tap the deep Pleistocene aquifer.

DEEP PLEISTOCENE ARTESIAN AQUIFER 

PIEZOMETRIC STTBPACB

The piezometric surface of the deep Pleistocene 

artesian aquifer (pi. 3) is generally higher than that of 

the shallow artesian aquifer, as shown by measurements in about 110 wells in April 1947. The generally 

higher pressure in the deeper aquifers is well known, 

and many well owners have found that the advantage 

of higher pressure or greater flow more than offsets the 

higher cost of drilling the deep well. The forms of 

the piezometric surfaces of the deep and shallow aquifers 

are similar in that they rise from the central part of 

the valley toward the mountain front. The piezometric surface of the deep aquifer also in all probability 

has a slighter gradient under the Highland and Orem 

benches than at lower altitudes in the valley, but there 

are no wells in these areas to provide confirmatory 

evidence. The contours of the deep aquifer arch 

around the Provo bench and suggest that water in the 

aquifer fans out from the mouth of Provo Canyon. 

Along the edge of this broad mound there are two 

embayments, probably produced by discharge from 

wells in Geneva and in Lakeview.

The piezometric surface of the deep Pleistocene 

aquifer under the alluvial fans of Dry Creek and 

American Fork has the form of a single broad southwest-sloping ridge. Whereas the piezometric surface 

for the shallow aquifer indicates movement along and 

outward from axes under Dry Creek and under American Fork River, the contours for the deep aquifer 

indicate movement outward from a single axis that 

trends southwestward from the Highland bench. The 

shape of the piezometric surface of the shallow aquifer 

is readily explained by movement in separate alluvial 

fans formed respectively by Dry Creek and American 

Fork River, both conspicuous in the present physiography. The contrasting form of the piezometric 

surface of the deep aquifer suggests that the deeper 

aquifer is a single alluvial fan, and that when it was 

formed Dry Creek and American Fork River were 

combined in one stream below the mouths of the two 

canyons.

The contrasting forms of the two piezometric surfaces 

result in a marked difference in head in sec. 21, T. 5 S., 

R. 1 E., where the bulge in the piezometric surface for

the deep aquifer coincides with the embayment in the 

surface for the shallow aquifer between the Dry Creek 

and American Fork River fans. There the artesian 

pressure of wells reaching the deep aquifer is nearly 

50 feet higher than that of wells in the shallow aquifer. 

Because this area is low topographically, the deep 

artesian wells have shut-in pressures 60 to 80 feet 

above the land surface, the highest in Utah Valley.

CONSUMPTIVE USE

Many of the wells that yield water from the deep 

artesian aquifer are south and west of Lehi, where 

most are used for irrigation. The effect of withdrawal 

from these wells is shown on plate 3 by the curvature 

of the 4,530- to 4,565-foot contours. The effect of well 

discharge is much more pronounced during the irrigation season. (Taylor and Thomas, 1939.) Wells at 

the Geneva Steel Co. plant also draw large quantities 

of water from this deep aquifer, and have caused an 

embayment in the piezometric surface in sec. 8, T. 6 S., 

R. 2 E. Other deep wells are distributed along the 

belt from Lehi to Provo, many of them close to the 

limit of artesian flow for the shallow aquifer.

RECHARGE AREAS

The piezometric surfaces for both the steep and 

shallow Pleistocene artesian aquifers, as mapped on 

plate 3, rise toward the east and indicate that the 

recharge area is in that direction. But these piezometric surfaces cover only the area in which the water 

is confined under artesian pressure, and do not extend 

eastward into the recharge area. Toward the east the 

confining layers above the artesian aquifers grade into 

coarser materials, and thus cease to be confining layers. 

In the recharge area, from which water enters the 

artesian aquifers, water in coarse sediments of Lake 

Bonneville and pre-Lake Bonneville age is probably 

unconfined. This recharge area is probably limited to 

the mouths of the canyons and perhaps to a narrow 

band along the base of the range. The canyon streams 

are the principal source of water that enters these 

coarse deposits, for in wells near the recharge area the 

water level rises markedly during the period of peak 

stream discharge, and the amount of rise is related to 

the quantity of water discharged during the annual 

freshet. (See fig. 18.)

Most of the wells in the northwest part of the 

valley reach the deep Pleistocene artesian aquifer, and 

the piezometric surface of that aquifer can be delineated 

as far as a mile west of the Jordan River. This surface 

slopes westward at least to the westernmost well in 

the area, and it is concluded that the water even along 

the western border of the valley comes from the east 

side of the valley. Thus there is no evidence that any
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 85

appreciable quantity of ground water enters Utah 

Lake Valley from the small drainage basin north of the 

Lake Mountains. From the small amount of stream 

flow and precipitation along the entire west side, it is 

inferred that negligible quantities of ground water 

originate on that side of the valley.

MOVEMENT AND NATURAL DISPOSAL

The ground water that enters the recharge areas 

along the east flank of the valley moves westward 

through the pre-Lake Bonneville deposits. The movement is most rapid through the coarse gravels and 

boulders near the mountains, and slower farther west 

where those beds grade into materials of finer texture; a 

greater hydraulic gradient is required to force the water 

through those finer sediments. The least permeable 

materials, especially the clay-sized particles, act as 

confining layers above the beds of coarser materials, 

creating artesian pressure within the several aquifers. 

Near the lower margins of the shore deposits of the 

Lake Bonneville group this artesian pressure is 

sufficient to produce flowing wells.

Water is discharged naturally from the pre-Lake 

Bonneville aquifers within the area where flowing wells 

are obtained and where, therefore, the piezometric 

surface is above the land surface. The springs at the 

Lehi Sugar Factory and around Powell Slough probably 

discharge water that comes chiefly from the shallow 

artesian aquifer, for sizable embayments in the piezometric surface indicate that water is lost from the 

aquifer in those areas. The deep artesian aquifer 

appears to contribute to the Sugar Factory springs 

also.

Probably the greatest amount of natural discharge 

from these aquifers, however, is by upward seepage of 

water through the so-called impermeable beds deposited 

on the floor of Lake Bonneville—seepage at an exceedingly slow rate, perhaps, but over so extensive 

an area that the aggregate discharge is large. Studies 

have not been made in Utah Valley to ascertain the rate 

of upward movement, or even to prove that there is such 

seepage. It is inferred to be an important item, however, on the basis of (1) the conclusion from studies 

in Cache Valley (Israelsen and McLoughlin, 1942, 

pp. 11-15) that there is upward seepage through 

similar clays at a rate of more than 200 gpm per square 

mile of area; (2) the fact that the gradient of piezometric surfaces of both deep and shallow Pleistocene 

aquifers continues to the shore of the Utah Lake, 

indicating natural discharge farther west (pi. 3); 

and (3) the evidence that Utah Lake receives far more 

water than is measured in inflowing streams (pp. 69-72). 

The question of upward movement from artesian 

aquifers is treated further on pages 87-89.

TERTIARY AND TERTIARY(?) DEPOSITS

Information concerning the water-bearing properties 

of Tertiary deposits is nearly all obtained from well 

(D-6-2)8bcd-4, as of 1949 the deepest well of the 

Geneva Steel Co. (See figs. 5 and 21.) This well 

draws water from strata several hundred feet below 

the aquifers of the Pleistocene pre-Lake Bonneville 

deposits. The strata considered to be of Tertiary age 

are encountered below the depth of 490 feet. They 

consist predominantly of gravel, with thinner beds 

of sand, and a few thin beds of clay. Clay-sized 

particles also make up an appreciable proportion of 

the poorly sorted materials encountered at depths of 

530 to 575 feet, and 720 to 745 feet. The sediments 

appear to be dominantly of fluvial origin, but some of 

the beds of well-sorted sand may be eolian. Plant 

materials at several horizons are indicative of subaerial accumulation.

The deposits in the Geneva well that are believed to 

be Tertiary include four or more aquifers separated by 

relatively impermeable strata. These aquifers are 

composed dominantly of gravel, with some sand, as 

identified in the driller's log and in sample cuttings. 

Three zones of permeable strata are confirmed by the 

electric log that was made of the lower 200 feet of hole 

after casing had been cemented in to a depth of 618 

feet. The deepest aquifer, 746 to 818 feet below the 

land surface, was developed for water supply. The 

completed well had 16-inch casing, grouted, to a depth 

of 618 feet; lead plug at the joint between 16-inch and 

12-inch casings; 12-inch casing from 618 to 744 feet; 

12-inch reinforced well screens from 744 to 808 feet; 

and solid 12-inch casing to bottom of hole at 828 feet.

CHARACTERISTICS OF DEVELOPED AQUIFER

The driller reported sand and gravel between depths 

of 746 and 788 feet and gravel and boulders from 788 

to 810 feet. A bed of sand and gravel between 810 

and 818 feet is also a part of the aquifer, but the electric 

log indicated that this deepest part was somewhat less 

permeable, and screens, therefore, were not set in the 

lower 10 feet of the aquifer. The aquifer is underlain 

and overlain by beds of clay-sized material, of which 

calcium carbonate is a major constituent.

Samples of the water-bearing sediments collected at 

5-foot intervals during the drilling consist predominantly of rock fragments broken by the rotary rig. 

In the zone between depths of 788 and 810 feet some 

fragments are as large as an inch across and evidently 

came from boulders that probably exceeded 6 inches in 

diameter. Fragments of gray quartzite constitute 

from 45 to 60 percent of each sample and fragments of 

limestone make up an additional 35 to 45 percent. 

Other rock fragments identified include green quartz-
86 LAKE BONNEVILLE

ite, purple quartzite, black shale, and andesite, all of 

which are derived from rocks that crop out in the 

drainage basin of the Provo River. The position of the 

well opposite the mouth of the Provo River canyon 

also indicates that the sediments were deposited chiefly 

by the Provo River. All samples contain quartz sand 

in quantities ranging from 3 to 10 percent of the total 

sample.

DISCHARGE TEST OF WELL (D-6-2)8bcd-4

For testing purposes, a discharge pipe with gate 

valve was connected to the horizontal arm of a T on 

the casing, and the vertical arm of the T was extended and covered to permit installation of a pressure 

gage. Measurements of the discharge of the well 

were made over a 1.5-foot Cipoletti weir. Immediately after completion of the well, the discharge is 

reported to have been 350 gpm by natural flow. The 

well was then treated with dry ice, and the discharge 

was increased to a reported 1,400 gpm. For a period of 

several weeks the well flowed freely except for a few 

moments each day when it was closed to measure the 

shut-in pressure. During this period the discharge 

was at an essentially constant rate, as reported by 

engineers of the Geneva Steel Co., and the daily measurements showed only a slight fluctuation of shut-in 

pressure.

On April 16, 1948, three weeks after completion of 

drilling, and after the well had been flowing for several 

days, a multiple-step drawdown test of the well was 

made. The first operation involved the closing of the 

well for 35 minutes and the determination of the 

recovery curve. Subsequently the well was opened 

sufficiently to discharge at a rate equivalent to onefourth of its free flow, then one-half, and then threefourths of its free flow, for periods of an hour'each; 

finally the valve was opened fully and the flow was 

measured for 10 minutes. The results of these operations are summarized in table 26, and details are shown 

graphically in figure 21.

TABLE 26.—Multiple-step drawdown test of Geneva Steel Co. well 

(D-6-2)8bcd-4 April 16, 1948

Operation

Period, 

in 

minutes

35 

60 

60 

60 

10

Average 

discharge 

in 

period, 

cfs

0.0 

.75 

1.45 

2.15 

2.8

Temperature in 

degrees 

F.

70.3 

70.5 

70.6 

70.7

Head, in feet, above 

level of free flow

Beginning of 

period

35.9 

32.3 

26.2 

15.45

End of 

period .

36.2 

32.05 

26.1 

15.1 

.0

When the well was closed the recovery was very 

rapid; within 90 seconds of closing the head was 36.0 

feet above the flow line, and in the next 33% minutes

there was an increase in head of only 0.2 foot. In 

each stage of the test the rate of discharge remained 

constant within the limits of accuracy of the weir, and 

no valve changes were necessary to maintain uniform 

discharge. After the initial decline, which occurred 

abruptly each time the valve was opened wider, the 

head decreased only a few tenths of a foot during each 

hour of constant discharge.

Certain characteristics of the aquifer and the well are 

determined from the test, on the basis of formulas

§ ,

o ;

FIGURE 21. Discharge and drawdown during test of well (D-6-2)8bcd-4, April 18,

1948.

derived by Jacob (1946, pp. 1047-1063). The transmissibility of the aquifer is derived by the formula

2.30#log10 (^

T=

in which s2 and Si represent the drawdown in feet at 

times tz and t\, and Q is the discharge in second-feet 

during the test period. For the period when the well 

was discharging 2.15 cfs (sec-ft), or 965 gpm, the 

transmissibility was computed to be 0.20 cfs (about 

130,000 gallons per day) per foot width of aquifer at 

unit (100-percent) hydraulic gradient. Taking the 

effective thickness of the aquifer as the 60-foot screened 

portion, the permeability is computed to be about
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 87

2,200 gallons per day per square foot at unit hydraulic 

gradient. However, it is not certain that gravels 

above and below those screened did not contribute 

water to the well; if they did, the average permeability 

of the 60-foot section is less than 2,200.

When the well is flowing freely at the rate of 2.8 cfs 

(1,250 gpm), the apparent specific capacity is about 35 

gpm per foot of drawdown. No other wells reached 

this aquifer at the time the test was made, and therefore no determinations were made of the hydraulic 

gradient or of the rate of movement of water through 

the aquifer.

SOURCE AND MOVEMENT OF WATER IN TERTIARY(?) AQUIFERS

Throughout most of northern Utah Valley there are 

no wells tapping the Tertiary(?) aquifers, and therefore no data concerning the form of the piezometric 

surface. West of Lehi, however, measurements were 

made of the shut-in pressure in seven wells that reach 

Tertiary (?) deposits. The piezometric surface shown 

by these measurements (pi. 3) has a westward gradient 

of about 25 feet per mile, about the same as the piezometric surface of the deep Pleistocene aquifer. 

The Tertiary (?) aquifer has an artesian pressure 

generally 5 to 10 feet higher than that of the deep 

Pleistocene aquifer; but where the pressure of the deep 

Pleistocene aquifer has been lowered by well discharge 

(in part because of wells permitted to flow continuously) the piezometric surface of the Tertiary(?) 

aquifer may be as much as 20 feet higher.

In the Geneva area, the general pattern of accumulation of valley sediments described in preceding chapters, 

and the hydrologic data obtained for overlying aquifers 

accumulated under similar conditions, indicate that 

the water comes from the east—probably from the 

canyon of the Provo River.

Any valid conclusions as to the source and movement 

of water in the Tertiary (?) aquifers penetrated by the 

deep Geneva Steel Co. well must offer a satisfactory 

explanation for the comparatively low mineral content 

of those waters. The water from the deep well has less 

dissolved solids than the water from any of the overlying 

aquifers, and less than is carried by the Provo River at 

low stages. Table 27 summarizes the analyses in 

relation to depth from which water is obtained. The 

waters in aquifers of different depths have similar 

relative proportions of chemical constituents, but these 

differ in concentration, as shown in figure 22.

The waters in the Tertiary (?) strata are evidently 

far less mineralized than that of the Provo River at 

low stages but are not notably different from the waters 

of numerous springs that rise in the Wasatch Range 

and flow to the Provo River. It is likely that during 

the spring freshet the water in the river is far less

TABLE 27.—Mineral content and hardness of water in streams, and 

in aquifers of various depths at Geneva, Utah

Source of water

31-46).

(July 31-46).

Do....... —— —— ——— Do . ... _ .-.-- -

Do.——————————

Depth 

in feet

130

192

285

340

440

639

707

746-818

Description

—. .do....— — -- —

Shallow Pleistocene

aquifer.

aquifer.

——do.——————

__ do.. ___ . ___

——do...——.———

Total 

hardness 

as 

CaCOj 

(ppm)

246

100

90

255

233

147

141

168

58

88

Dissolved 

solids, 

ppm

358

169

153

396

329

211

213

210

164

156

152

mineralized than at low stages, but periodic sampling 

and analyses have not been made. It is conceivable 

that water having the chemical composition of that in 

the Tertiary (?) aquifers could be drived from the Provo 

River drainage basin under present hydrologic conditions. For an explanation of the increased concentration at shallower depths, however, it is necessary to 

consider other factors related to ground-water movement.

Measurements of the artesian head in adjacent wells 

of different depths—or of the heads for different aquifers 

encountered during construction of a well—show that 

the water in the deep aquifers is under considerably 

greater head than that in shallow zones. During the 

cable-tool drilling of the Geneva Steel Co. well (D-6-2) 

8bcd-2 in 1943, the head of the water in the deep 

Pleistocene aquifer at depths of 285 to 460 feet was 

determined to be 20 feet greater than in the shallow 

aquifer of lesser depth. The differential head between 

the Tertiary (?) aquifers from 633 to 707 feet deep and 

the deep Pleistocene aquifer was 2 feet at that time. 

In 1948 when the deep well was drilled, the differential 

head between deep and shallow Pleistocene aquifers 

had decreased to about 17 feet, and that between 

Tertiary (?) and the deep Pleistocene aquifers had 

increased to about 5 feet, presumably because the head 

in the deep Pleistocene aquifer had been reduced by 

interference of several wells that were flowing during 

the 1948 measurements.

Differential head in adjacent wells that tap aquifers 

of different depths has commonly been attributed to 

structural or stratigraphic conditions—as, for instance, 

in areas where the strata are inclined, the deeper aquifers 

crop out at higher altitudes than do the shallow beds. 

Also, in certain localities of the Lake Bonneville basin 

the Tertiary (?) sediments crop out on mountain flanks 

above the highest shore line of Lake Bonneville, and the 

head in wells reaching those sediments may be higher 

than in adjacent wells tapping Pleistocene strata.
EXPLANATION 

Sodium 

SHALLOW PLEISTOCENE AQUIFER I DEEP PLEISTOCENE AQUIFER I PRE-PLEISTOCEN

FIGUBK 22.—Chemical analyses of water from wells of the Geneva Steel Co. Data from Defense Plant Corp.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 89

In Utah Valley, however, the Lake Bonneville group 

laps against the Paleozoic rocks of the Wasatch Range, 

and there are no higher outcrops of earlier Pleistocene 

or Tertiary (?) strata. Furthermore, in the long history 

of accumulation of the fill in Utah Valley, there is no 

basis for assuming that the coarse detritus of the earliest 

deposits would be higher on the mountain flank than 

that of more recent deposition. Instead, during this 

tune the increasing thickness of valley fill would develop 

a valley floor of progressively increasing width, with 

the result that the zone of deposition of the coarser 

detritus—the prime water-bearing strata—should 

encroach more and more on the mountain flank and 

thus be generally at higher altitude and farther from 

the center of the valley in the later part of the period 

of accumulation. The sediments encountered in the 

deep well at Geneva tend to confirm this hypothesis: 

the coarsest detritus, consisting of boulders and 

cobbles, was encountered near the bottom of the well, 

and overlying aquifers are all of finer texture, although 

they are similarly of fluviatile origin.

The boulder bed that forms the developed aquifer 

hi the deep well undoubtedly extends eastward toward 

the mouth of Provo Canyon, and probably is covered 

and overlapped by later Tertiary (?) gravels and then 

by coarse detritus of Pleistocene age. The strata of 

fine-textured material, including the lake clays shown 

in the log of the deep well, undoubtedly become thinner 

to the east. It is not known whether any of these 

fine-textured strata extends eastward as far as the 

mouth of the canyon, and the drilling of a deep well at 

that locality would provide valuable information on 

that question. In any case it is anticipated that the 

unconsolidated materials near the mouth of the canyon 

as well as in the lower part of the canyon will be predominantly coarse. These coarse materials are considered to constitute a common recharge area for the 

Pleistocene and older aquifers of the valley fill. But if 

all these aquifers have a common source of water, the 

differential head is not accounted for in the recharge 

area. Rather, it is believed that this differential head 

is developed within the area of artesian flow, as suggested below.

The fine-textured strata that intervene between the 

aquifers are far less permeable than the aquifers, but 

they are presumably slightly pervious. Israelsen and 

McLaughlin (1942, pp. 11-15) have shown by experiments in northern Utah that water moves upward 

through slightly pervious clays of the Lake Bonneville 

group overlying an artesian aquifer, and have noted a 

progressive decrease hi head at successively higher 

levels hi the clay bed. The loss of head in a 35-foot 

clay bed amounted to 15.2 feet, and these authors conclude that this loss of head is accompanied by an

upward movement of water through the clay, at an 

estimated rate of 200 to 250 gpm per square mile of 

area.

The head measured in the several aquifers at Geneva 

may similarly be analyzed for indications of possible 

movement of water between aquifers. The differential 

head between the shallow and deep Pleistocene aquifers, 

amounting to 20 feet, is sufficient to suggest an appreciable upward movement of water from the deep 

aquifer. The water in underlying Tertiary (?) aquifers 

has a slightly greater head than that in the deep 

Pleistocene aquifer, and it is inferred that there may 

also be some upward movement from the Tertiary (?) 

aquifers.

Upward movement of water through the fine-textured 

materials that separate the aquifers may well account 

for the increased concentration of chemical constituents 

in the water at shallower depths. Samples from these 

fine-textured beds contain a large proportion of calcium 

carbonate, which is readily dissolved and would increase 

both the hardness and the total solids in the water of the 

upper aquifers. Chemical analyses indicate that the 

mineral constituents hi the water hi the deep Pleistocene aquifer are moderately greater than in the Tertiary^) aquifers. In the shallow Pleistocene aquifer, 

where there is inferred to have been much greater 

upward movement of water from deeper strata, the 

waters are far more mineralized.

WATER FROM DEEP SOURCES

Wells at the Saratoga Springs resort discharge water 

at a temperature of about 110° F.—about 40° higher 

than the water yielded by the Tertiary(?) aquifer in 

the Geneva Steel Co. deep well. Although these wells 

are less than 200 feet deep, they have been drilled in 

the vicinity of natural warm springs. The temperature 

indicates that these springs and wells yield water from 

deep sources, rising probably along a fault. The 

waters are not highly mineralized and may well come 

from valley fill similar to that penetrated by other wells, 

but at considerably greater depth. Seeps warm enough 

to keep snow melted throughout the winter have been 

reported by sheepherders along the east base of the 

Lake Mountains, south of Saratoga.

CHEMICAL QUALITY OF WATER

The present studies included no investigation of the 

geochemistry of the ground water. However, analyses 

have been made by various agencies of a relatively 

small number of samples of water from streams and 

wells. These analyses indicate that the waters of 

northern Utah Valley are generally calcium bicarbonate 

waters, commonly containing 200 to 400 ppm of dissolved solids, and having hardness (as calcium carbonate) ranging from 150 to 300 ppm. The calcium bi-
90 LAKE BONNEVILLE

carbonate is derived from the limestones which are 

widespread over the drainage basin tributary to the 

Utah Lake Valley, particularly in the Wasatch Range.

The water in streams might be expected to have a 

higher concentration of chemical constituents when 

those streams are at low stage than when the stream 

discharge is high. At low stage, generally from 

August to the following March, much of the flow is 

derived from ground water, part of which is return 

flow from irrigation. On the other hand, the maximum 

flows are derived from melting snow on the drainage 

area during the spring and early summer.

Analyses of artesian well waters at the Geneva Steel 

plant indicate that water from the shallow Pleistocene 

aquifer generally is more concentrated than that from 

the deep Pleistocene aquifer, although the proportions 

of the individual constituents are similar. In turn, 

the water in the deep Pleistocene aquifer is more concentrated than that in the Tertiary(?) aquifer. The 

analyses are represented graphically in figure 22. The 

increased concentration of mineral constituents in 

shallower strata, as well as the decreased artesian 

pressure of water in those strata, has been attributed 

(p. 89) to the upward movement of water from deep 

aquifers through shallower strata.

MAXIMUM POTENTIAL DEVELOPMENT OP 

WATER RESOURCES

What is the maximum potential development of 

water resources? The answer to this question is of 

vital importance to Utah's most densely populated 

region, because the ultimate limits of its agricultural 

and industrial economy will be set by the quantity of 

water that the Jordan River drainage basin can yield 

perennially for those developments. The history of 

water utilization (pp. 61-66) shows how the use of 

water in the drainage basin has been increased in the 

past century. In the early days of settlement, primary 

rights to the minimum flow of a stream constituted the 

only secure source of irrigation water when water was 

most needed; on the other hand, there were flood discharges into Great Salt Lake in nearly every year. 

At the present time the dependable yield of water 

throughout the irrigation season has been increased 

manyfold by storage in headwater lakes, by diversions 

from the Weber River drainage basin into Deer Creek 

reservoir, by manipulation of Utah Lake levels through 

floodgates and pumping, and by withdrawals from wells. 

For the last quarter century diversions into canals 

have constituted practically the entire output of Utah 

Lake, and the volume of these diversions has varied 

from 78,000 acre-feet in 1935 to 337,000 acre-feet in 

1938. There has been practically no unused outflow 

from Utah Lake to Great Salt Lake since 1925.

As the dependable yield of the system has been 

increased, the individual water users have sought recognition and adjudication of their respective water rights. 

The rights have been defined for several tributaries, 

and designated "primary" or "secondary" or subdivided further according to various classes. Court 

decrees set the limits of use of water from the tributaries, 

and the associated canal companies that use water 

from Utah Lake lay claim to all water not used as well 

as the return flow from users holding these established 

rights. The suit of Salt Lake City et al. v. Tamar 

Anderson et al. seeks to bring about a comprehensive 

determination of the rights of all users to the surface 

water and ground water of Utah Lake and its tributary 

drainage basin. (See p. 63.)

Yet, there are large quantities of water that leave 

the Utah Lake drainage basin unused, although the 

surface water is generally regarded as fully appropriated, and many believe that the ground water should 

be similarly classified. The computed evaporation 

from the lake surface during nearly every year is 

greater than the quantity taken by pumping and 

gravity diversions for beneficial use. In 31 years 

(1916 to 1946, inclusive) the average annual evaporation 

was estimated to be about 315,000 acre-feet, compared 

with pumped and gravity diversions averaging 245,000 

acre-feet a year. The evaporation from land areas 

and transpiration by native vegetation have not 

been estimated, but it is certain that the total in Utah 

Valley represents an additional natural loss of many 

thousand acre-feet each year.

These natural losses have a "priority" well above that 

of most of the established rights, and therefore cause a 

drastic reduction of the water available for beneficial 

use, particularly in dry years. In the drought year 

1935, precipitation over the Utah Lake drainage basin 

was 55 to 70 percent of the long-term average, but 

because the natural evapotranspiration losses were not 

reduced in proportion, the computed inflow to Utah 

Lake was only 46 percent of average. Because of the 

reduced volume of water in Utah Lake and the smaller 

lake surface that year, the computed evaporation was 

only about 60 percent of average, but after this natural 

loss the users of Utah Lake were able to obtain less than 

30 percent of the quantity normally used by them, 

and had to pump the lake nearly dry.

The excessive natural losses of water in Utah Valley, 

and particularly from Utah Lake, have long been recognized, and several methods have been proposed for 

reducing those losses. Some of these suggestions 

involve the concentration of Utah Lake storage in a 

smaller area by diking off the shallower parts of the 

lake. The Provo River project of the Bureau of 

Reclamation includes a proposed earth-and-rock-fill
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 91

barrier across the mouth of Goshen Bay, a southwesterly arm of the lake; the dike, to be 5% miles long, 

would reduce the surface area of the lake by 27,300 

acres, which is about 20 percent of the lake surface at 

compromise level. It has also been proposed to dike 

off the smaller Provo Bay, along the east shore south of 

the city of Provo. Storage in deep and narrow canyon 

reservoirs, particularly in headwater areas, would be 

subject to less evaporation loss than in Utah Lake; 

the Deer Creek reservoir and headwater lakes thus are 

superior to Utah Lake in efficient storage. However, 

good additional reservoir sites are rare, and storage of 

anything like the volume in Utah Lake could be 

achieved only at great cost.

It is quite possible that the ground-water reservoir 

could be used to advantage in providing additional 

water for beneficial use. If the artesian pressure were 

sufficiently reduced by pumping from properly spaced 

wells, some of the water now lost by evapotranspiration in the lower part of Utah Valley might be diverted 

instead to beneficial use. And if water were withdrawn 

by pumping from the coarser gravels of the valley, it is 

likely that this water would be replaced by seepage 

from the streams. Thus water would be stored underground, rather than hi Utah Lake, and evaporation 

losses would be at a minimum. If the ground-water 

reservoir were so utilized, the additional water salvaged from natural losses would be obtained at considerable cost, because of the pumping required. Indeed, 

any method of increasing the amount of water for 

utilization will entail large expenditures. Nevertheless the projects that will reduce evapotranspiration 

losses offer perhaps the only method of utilizing substantial additional quantities of water within the 

drainage basin, because these natural losses constitute 

most if not all the water still unappropriated.

A detailed knowledge of the ground-water reservoirs—the storage of water in aquifers and the rates 

and volumes of recharge, movement, and discharge of 

ground water—is prerequisite to an evaluation of the 

effectiveness of these projects in reducing evapotranspiration losses. It is necessary to know, for instance, 

how much water enters Utah Lake by upward movement from artesian aquifers before we can be assured 

that evaporation can be eliminated by diking off portions of Utah Lake. A knowledge of the sources and 

rates of movement of ground water lost by evapotranspiration in the land areas of Utah Valley must 

precede any successful developments for diverting that 

water to beneficial use. And if the ground-water 

reservoir is to be used for storage of any part of the 

water that now flows to Utah Lake, we must know the 

areas and potential rates of recharge to that reservoir

247743—54———7

as well as the rates at which water could be transmitted 

through each aquifer.

Determination of the hydraulic characteristics of the 

several aquifers, hi part from tests of existing wells but 

requiring also the drilling of several wells specifically 

for test purposes, would permit the calculation of the 

quantity of water stored underground, and of the rate 

and direction of movement of water in each aquifer. 

Tests similar to those undertaken by Israelsen in Cache 

Valley would determine the extent* of upward movement from the artesian aquifers. Any attempt to 

develop the water now lost by evapotranspiration should 

be accompanied by hydrologic studies sufficiently comprehensive to prove that the water is being diverted 

as intended, and not from water users having established rights.

It has been demonstrated that an industry requiring 

large amounts of water can be established in Utah Valley 

without infringing upon the rights of other water 

users. The Geneva Steel Co. pumps water at the rate 

of 370 cfs (240 million gallons per day), which is about 

80 percent of the long-term average flow of the Provo 

Kiver. The net consumptive use within the plant, 

however, is 10 to 12 cfs, of which about half is lost by 

evaporation from the reservoir, and the rest is consumed by coke quenching, descaling, cooling, and other 

processes.

The steel plant came late hi the development of the 

valley, and therefore the water rights for the plant 

were necessarily acquired on a catch-as-catch-can 

basis. The Defense Plant Corp. had the advantage 

of excellent cooperation from holders of prior rights, 

and of a temporary lease on water from Deer Creek 

reservoir pending completion of the project and delivery 

to the ultimate users. Purchase of the property brought 

rights to 128 wells with a claimed combined flow of 

4,400 gpm, plus rights in the irrigation season to the 

flow of several springs and drains yielding about 2,500 

gpm on the average. These basic rights were sufficient 

to furnish the water for consumptive use.

In the development of artesian water supplies, all 

128 wells on the property were plugged and sealed, and 

a dozen wells of large capacity were drilled near the 

center of the property. These wells yielded from 3,000 

to 5,400 acre-feet annually between 1944 and 1948, 

which is somewhat more than the annual yield of the 

128 wells during the period from 1938 to 1940 as computed by the State Engineer (2,900 to 3,400 acre-feet a 

year). This greater yield, however, has caused no 

observable loss in pressure head hi private wells adjacent to the steel mill, for artesian pressures in the 

vicinity have fluctuated in response to precipitation and 

runoff hi the same degree as other wells in Utah Valley.
92 LAKE BONNEVILLE

The steel-mill wells, because they are remote from the 

plant boundaries, cause less interference in many outlying wells than was created by individual wells that 

formerly discharged within the plant area.

The supply from wells was augmented in 1948 by 

production from a deep well, capable of yielding about 

1,200 acre-feet a year. It was the only well to tap a 

Tertiary(?) aquifer in the vicinity of Geneva, and it 

caused no interference even in adjacent wells of the 

steel company, which tapped Pleistocene aquifers.4

The steel plant's vast requirements for circulating 

(nonconsumptive) water were met by diversions from 

the Provo River, either by pumping at the mouth of 

the canyon or by flow in the Lake Bottom Canal and 

West Union Canal. To insure that these diversions 

would not deplete the storage in Utah Lake, an agreement obligated the company to return to Utah Lake a 

quantity of water equivalent to the water diverted from 

the river, plus the nonirrigation flow of springs and 

drains, plus all water developed within the plant area 

by subsurface drams. Comparison of the inflow to 

Utah Lake before and after the plant was placed in 

operation shows that Utah Lake received quantities of 

water from the plant area substantially greater than 

the amount of water diverted from the river for plant 

use. (See table 28.) The excess may be due in part 

to climatic conditions, because the later years were 

somewhat wetter than the prewar years, and a greater 

flow from the area to the lake would be expected. But 

certainly a substantial part of the excess represents 

water salvaged by the company from loss by evapotranspiration within the steel plant area.

TABLE 28.—Annual flow to Utah Lake, in acre-feet, from Geneva 

Steel plant area

Year

Total inflow 

to Utah 

Lake

Diverted 

from Provo 

River

Return flow 

from plant 

area

Developed 

by subsurface 

drains

Area Used for Agriculture

1938 1 __-_____

1939 !_________

1940 i_ ________

18, 800 

16, 400 

14, 400

2 16, 700 

2 14, 400 

2 13, 000

2, 100 

2,000 

1,400

Area Used for Steel Plant

1944 3

1945 5 __ _--__--

1946 5 -_-__--_-

1947 3 ----__-_-

1948 3 _ ________

20, 300

24, 666

25, 900

4 12, 400

* 14, 500

4 15, 100

7,900

9,500

10, 800

3,500

5,700

8,300

1 From Watson, Gardner, and Harding survej.

2 Discharge from Lake Bottom and West Union Canals.

3 From records of the Geneva Steel Co.

4 Diverted from Lake Bottom and West Union Canals, and from Deer Creek 

reservoir and Provo River by pumping at mouth of canyon. 

6 Plant in operation for only a part of the year.

4 Since the completion of this report the Geneva Steel Co. (in 1950 and 1951) has 

drilled four more large wells into Tertiary (?) aquifers. These wells range in depth 

from 1,066 to 1,192 feet, and upon completion they yielded 2,200 to 3,000 gpm each 

by artesian flow.

The table shows that the quantity developed by the 

subsurface drains (constructed to lower the high water 

table in the plant area, and thus agents for reducing the 

areal evapo transpiration) is from two to five times as 

great as the total return flow from the area in prewar 

years. In 1948 the Geneva Steel Co. released 3,300 

acre-feet more water to the lake than was required to 

meet all its obligations with respect to diverted surface 

water, non-irrigation-season spring flow, and developed 

subsurface water. This surplus represented more than 

half the water yielded by the company's wells. Subsequent studies show that the steel plant has salvaged 

within its area enough water to balance its consumptive-use requirements of 8,000 to 9,000 acre-feet a year 

(Thomas, 1952).

It must be concluded, therefore, that the Geneva 

Steel Co. even with its enormous use of water, does not 

deplete the net available supplies as much as did the 

same property under an agricultural economy, and that 

the best prospect for development of additional water 

supplies in the valley lies in the possibility of similarly 

salvaging water now lost by natural processes. Such 

development requires an adequate knowledge of the 

hydrology, intelligent planning, and a wise management 

of the supply and its uses.

SELECTED BIBLIOGRAPHY

Abbe, Cleveland, 1901, The rainfall and evaporation of Great 

Salt Lake: Monthly Weather Rev., vol. 29, pp. 68-69.

Adams, T. C., 1932, Some hydrologic features of Great Salt 

Lake: Utah Eng., vol. 6, no. 5, pp. 1-3, 5.

———— 1938, Recent depositions of salt from Great Salt Lake:

Jour. Geology, vol. 46, pp. 637-646. 

Allee, W. C., 1926, Some interesting animal communities of

northern Utah: Sci. Monthly, vol. 23, pp. 481-495. 

Alter, J. C., 1919, Normal precipitation in Utah: Monthly

Weather Rev., September. 

American Guide Series, 1942, Provo, Pioneer Mormon city:

Binford and Mort Co., Portland, Oreg. 

Anderson, G. E., 1915, Stream piracy of the Provo and Weber

Rivers, Utah: Am. Jour. Sci., 4th ser., vol. 40, pp. 314-316. 

Antevs, Ernst, 1925, On the Pleistocene history of the Great

Basin: Carnegie Inst. Washington Pub. 352 (Quarternary

climates), pp. 51-114.

———— 1948, Climatic changes and pre-white man: Utah Univ.

Bull., vol. 38, no. 20, pp. 168-191. 

Atwood, W. W., 1909, Glaciation of the Uinta and Wasatch

Mountains: U. S. Geol. Survey Prof. Paper 61. 

Auerbach, H. S., 1943, Father Escalante's journal 1776-77:

Utah Hist. Quart., vol. 11, pp. 64-66.

Baker, A. A., 1947, Stratigraphic sections in the Wasatch Mountains in the vicinity of ProvO, Utah: U. S. Geol. Survey

Oil and Gas Inv. Ser., prelim, chart 30. 

Bancroft, H. H., 1889, History of Utah: The San Francisco Co.,

San Francisco, Calif. 

Behle, W. H., 1942, The colonial nesting birds of Great Salt

Lake: Utah Min. Soc. News Bull., vol. 3, no. 2, pp. 59-63.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 93

Blackwelder, Eliot, 1910, New light on the geology of the 

Wasatch Mountains, Utah: Geol. Soc. America Bull., 

vol. 21, pp. 517-542, 767.

———— 1915, Post-Cretaceous history of the mountains of central western Wyoming: Jour. Geology, vol. 23, pp. 97- 

117, 193-217, 307-340.

———— 1931, Pleistocene glaciation in the Sierra Nevada and 

Basin Ranges: Geol. Soc. America Bull., vol. 42, pp. 865- 

922.

———— 1932, An ancient glacial formation in Utah: Jour. Geol., 

vol. 40, pp. 289-304.

———— 1934, Supplementary notes on Pleistocene glaciation in 

the Great Basin: Washington Acad. Sci. Jour., vol. 24, 

no. 5, pp. 217-222.

———— 1935, Summary of the pre-Cambrian rocks of Utah and 

Wyoming: Utah Acad. Sci. Proc., vol. 12, pp. 153-157. 

1939, Pleistocene mammoths in Utah, and vicinity: Am.

Jour. Sci., vol. 237, pp. 890-894. 

Bryan, K., and Albritton, C. C., Jr., 1943, Soil phenomena as

evidence of climatic changes: Am. Jour. Sci., vol. 241,

pp. 469-490. 

Butler, B. S., and others, 1920, Ore deposits of Utah: U. S.

Geol. Survey Prof. Paper 111. 

Calkins, F. C., and Butler, B. S., 1943, Geology and ore deposits

of the Cottonwood-American Fork area, Utah: U. S. Geol.

Survey Prof. Paper 201, pp. 38-40. 

Call, R. E., 1885, Quaternary and Recent Mollusca of the

Great Basin, with description of new forms: U. S. Geol.

Survey Bull. 11. 

Cameron, F. K., 1901, Application of the theory of solution to

the study of soils: U. S. Dept. Agr., Bur. Soils. 

Carlston, G. M., and Woolley, R. R., 1934, Some historical

earthquakes in Utah (abstract): Utah Acad. Sci. Proc.,

vol. 11, p. 171. 

Carpenter, E., 1913, Ground-water in Box Elder and Tooele

Counties, Utah: U. S. Geol. Survey Water-Supply Paper

333. 

Clarke, F. W., 1924, Data of geochemistry: U. S. Geol. Survey

Bull. 770, p. 159.

Clyde, G. D., 1931, Relationship between precipitation in valleys and on adjoining mountains of northern Utah: Monthly

Weather Rev., pp. 113-117, March. 

Cottam, W. P., 1926, An ecological study of the flora of Utah

Lake, Utah (manuscript report in files of Chicago Univ. 

Grad. School Sci.).

———— 1942, The flora of Great Salt Lake: Utah Min. Soc.

News Bull., vol. 3, pp. 33-35. 

Crawford, A. L., and Thackwell, F. E., 1931, Some aspects of

the mudflows north of Salt Lake City, Utah: Utah Acad.

Sci. Proc., vol. 8, pp. 97-105. 

Daniels, L. L., 1917, 6n the flora of Great Salt Lake: Am

Naturalist, vol. 51, pp. 499-506. 

Davis, W. M., 1903, The mountain ranges of the Great Basin:

Harvard Coll. Mus. Comp. Zoology Bull., vol. 42, pp. 129-

177.

—:—— 1905, The Wasatch, Canyon, and House Ranges, Utah: 

Harvard Coll. Mus. Comp. Zoology Bull., vol. 49, pp. 17-56.

———— 1925, The Basin Range problem: Nat. Acad. Sci. Proc., 

vol. 11, no. 7, pp. 387-392.

1926, Biographical memoir Grove Karl Gilbert: Nat

Eardley, A. J., 1934, Structure and physiography of the 

southern Wasatch Mountains, Utah: Michigan Acad. Sci. 

Papers, vol. 19, pp. 377-400.

———— 1938, Sediments of Great Salt Lake, Utah: Am. Assoc. 

Petroleum Geologists Bull., vol. 22, pp. 1305-1411.

1939, Structure of the Wasatch-Great Basin region:

Geol. Soc. America Bull., vol. 50, pp. 1277-1310. 

Eardley, A. J., and Haas, Merrill, 1936, Oil and gas possibilities in

the Great Salt Lake Basin: Utah Acad. Sci. Proc., vol. 13,

pp. 61-80. 

Eardley, A. J., and Hatch, R. A., 1940, Pre-Cambrian crystalline

rocks of north-central Utah: Jour. Geology, vol. 48, pp.

58-72.

———— 1940a, Proterozoic(?) rocks in Utah: Geol. Soc. America

Bull., vol. 51, pp. 795-843. 

Eckel, E. C., 1904, Salt industry in Utah and California: U. S.

Geol. Survey Bull. 225, pp. 488-495. 

Flowers, S., 1934, Vegetation of the Great Salt Lake region:

Bot. Gazette, vol. 95, no. 3, pp. 353-418. 

Forsling, C. L., 1931, A study of the influence of herbaceous

plant cover on surface runoff and soil erosion in relation to

grazing on the Wasatch Plateau in Utah: U. S. Dept. Agr.

Tech. Bull. 220. 

Frederick, E., 1924, The bacterial flora of Great Salt Lake

(unpublished thesis in files of Utah Univ.), May. 

Fremont, G. C., 1845, Report of the exploring expedition to the

Rocky Mountains in the year 1842, and to Oregon and north

California in the years 1843-44: Congressional documents,

28th Gong., 2d sess., S. Doc. 174. 

Gale, H. S., 1914, Notes on the Quaternary lakes of the Great

Basin, with special reference to the deposition of potash and

other salines: U. S. Geol. Survey Bull. 540, pp. 399-406.

———— 1915, Geologic history of Lake Lahontan: Science, new 

ser., vol. 41, pp. 209-211.

———— 1916, Potash in Salduro salt deposit: Eng. and Min. 

Jour., vol. 102, pp. 780-782, October 28.

———— 1917, Potash in 1916: U. S. Geol. Survey Mineral Resources U. S., 1916, pt. 2, pp. 73-171.

Gardner, D. I., 1936-47, Utah Lake and Jordan River distribution: Annual reports to the Utah State Engineer for the 

years 1936 to 1947 (mimeographed).

Gardner, F. D., and Jensen, C. A., 1901, Soil survey in Weber 

County, Utah; U. S. Dept. Agr., Bur. Soils.

Gianella, V. P., and Callaghan, Eugene, 1934, The earthquake 

of December 20, 1932, at Cedar Mountain, Nev., and its 

bearing on the genesis of Basin Range structure: Jour. 

Geology, vol. 42, no. 1, pp. 1-22.

Gilbert, G. K., 1875, Report on the geology of portions of Nevada, 

Utah, California, and Arizona: U. S. Geog. and Geol. Surveys W. 100th Mer. Rept. (Wheeler), vol. 3, pp. 17-187.

——— 1876, On the outlet of Great Salt Lake: Am. Jour. Sci., 

3d ser., vol. 11, pp. 228-229.

———— 1878, The ancient outlet of the Great Salt Lake: Am. 

Jour. Sci., 3d ser., vol. 15, pp. 256-259.

1878a, The recent history of Great Salt Lake: Philos.

Acad. Sci. Mem. 5, vol. 21, 303 pp. 

Eardley, A. J., 1933, Strong relief before block faulting in the 

vicinity of the Wasatch Mountains, Utah: Jour. Geology, 

vol. 41, pp. 243-267.

Soc. Washington Bull., vol. 2, p. 187.

———— 1878b, Utah Lake: Johnson's New Illustrated Cyclopedia, edited by F. A. T. Barnard and A. Guyot, vol. 4, p. 

1078.

———— 1880, Outlet of Lake Bonneville: Am. Jour. Sci., 3d ser., 

vol. 19, pp. 341-349.

———— 1880a, The Wasatch, a growing mountain: Philos. Soc.

Washington Bull., vol. 2, p. 195.
94 LAKE BONNEVILLE

Gilbert, G. K., 1882, Contributions to the history of Lake Bonneville: U. S. Geol. Survey 2d Ann. Rept., 1880-81, pp. 167-200.

———— 1883, A theory of the earthquakes of the Great Basin, 

with a practical application: Am. Jour. Sci., 3d ser., vol. 

27, pp. 49-53.

———— 1883a, Faults and earthquakes in Great Basin region: 

Science, 2d ser., vol. 2, pp. 580-581.

———— 1883b, Pre-Bonneville climate: Science, 2d ser., vol. 2, 

p. 170.

———— 1885, The topographic features of lake shores: U. S. 

Geol. Survey 5th Ann. Rept., pp. 69-123.

———— 1886, The inculcation of scientific method by example, 

with an illustration drawn from the Quaternary geology of 

Utah: Am. Jour. Sci., 3d ser., vol. 31, pp. 284-299.

———— 1890, Lake Bonneville: U. S. Geol. Survey Mon. 1.

———— 1928, Studies of Basin Range structure: U. S. Geol.

Survey Prof. Paper 153. 

Gilluly, James, 1928, Basin range faulting along the Oquirrh

Range, Utah: Geol. Soc. America Bull., vol. 39, pp.

1103-1130.

———— 1929, Possible desert-basin integration in Utah: Jour. 

Geology, vol. 37, pp. 672-682.

———— 1932, Geology and ore deposits of the Stockton and Fairfield quadrangles, Utah: U. S. Geol. Survey Prof. Paper 173.

Gould, L. M., 1939, Glacial geology of Boulder Mountain, Utah: 

Geol. Soc. America Bull., vol. 50, pp. 1371-1380.

Hague, Arnold, and Emmons, S. F., 1877, Descriptive geology: 

U. S. Geol. Expl. 40th Par. Rept. (King), vol. 2.

Hansen, G. H., 1928, Hairy mammoth skeleton in Utah: Science, 

new ser., vol. 68, p. 621.

———— 1934, An interpretation of past climatic cycles from observations made of Utah Lake sediments: Utah Acad. Sci.

Proc., vol. II, pp. 161-162. 

Hart, R. A., 1927, Some human influences on the oscillations

and trend of Great Salt Lake: Utah Eng., vol. 1, no. 10,

pp. 1-3, 6. 

Hayes, J. J., 1942, Great Salt Lake and its economic importance:

Utah Min. Soc. News Bull., vol. 3, pp. 11-23. 

Hintze, F. F., 1913, A contribution to the geology of the Wasatch

Mountains, Utah: New York Acad. Sci. Annals, vol. 23,

pp. 85-143. 

Howell, E. E., 1875, Report on the geology of portions of Utah,

Nevada, Arizona, and New Mexico examined in the years

1872 and 1873: U. S. Geog. and Geol. Surveys, W. 100th

Mer. Rept. (Wheeler), vol. 3, pp. 227-301. 

Huff, E. N., 1947, Memories that live, Utah County centennial

history, pp. 161, 190, 231, and 268, Springville, Utah. 

Hunt, C. B., Creamer, A. S., and Fahey, J. J., 1949, A newly

discovered type of clay deposit in Utah: Washington Acad.

Sci. Jour., vol. 39, no. 4, pp. 120-122. 

Hunt, C. B., and SokolofF, V. P., 1950, Pre-Wisconsin soil in the

Rocky Mountain region, a progress report: U. S. Geol.

Survey Prof. Paper 221-G. 

International Geological Congress, 16th sess., 1933, The Salt

Lake region: Guidebook 17, Excursion C-l, 149 pp. 

.Irving, Washington, 1837, The Rocky Mountains—or scenes,

incidents, and adventures in the Far West—digested from

the Journal of Capt. B. L. E. Bonneville of the Army of the

United States: Carey, Lea, and Blanchard, 2 vols.,

Philadelphia. 

Israelsen, O. W., and McLaughlin, W. W., 1942, Drainage of

land overlying an artesian ground-water reservoir: Utah

Agr. Exper. Sta. Bull. 242, pp. 11-15.

Ives, R. L., 1946, Desert ripples: Am. Jour. Sci., vol. 244, pp.

492-501, July. 

Jacob, C. E., 1946, Drawdown test to determine effective radius

of artesian well: Am. Soc. Civil Eng. Trans., vol. 112, pp.

1047-1063. 

Jennings, D. S., Fletcher, J. E., Wallace, M. H., Wilson, L., and

Zobell, I. D., 1946, Soil survey of the Salt Lake area: Soils

and Agr. Eng. Ser., 1936, no. 22. 

Jensen, C. A., and Strahorn, A. T., 1905, Soil survey of the Bear

River area, Utah: U. S. Dept. Agr., Bur. Soils. 

Jensen, J. M., 1924, History of Provo: New Century Printing

Co., Provo, Utah, 414 pp. 

Jones, D. T., 1944, Two protozoans from Great Salt Lake:

Utah Univ. Bull., vol. 35, nos. 8, 515. 

Jones, J. C., 1925, The geologic history of Lake Lahontan:

Carnegie Inst. Washington Pub. 352. 

Judd, N. M., 1926, Archeological observations north of the Rio

Colorado: Bur. Am. Ethnology Bull. 82. 

Kay, G. F., 1916, Gumbotil, a new term in Pleistocene geology:

Science new ser., vol. 44, pp. 637-638.

———— 1931, Classification and duration of the Pleistocene period:

Geol. Soc. American Bull., vol. 42, pp. 425-466. 

Kay, G. P., and Leighton, M. M., 1933, Eldoran epoch of the

Pleistocene period: Geol. Soc. America Bull., vol. 44, pp.

669-674. 

Kellogg, C. E., 1936, Development and significance of the great

soil groups of the United States: U. S. Dept. Agr. Misc.

Pub. 229. 

Keyes, Charles R., 1917, Orographic origin of ancient Lake

Bonneville; Geol. Soc. America Bull., vol. 28, pp. 164, 351-

374. 

King, Clarence, 1878, Systematic geology: U. S. Geol. Expl.

40th Par. Rept., vol. 1. 

Kirkpatrick, R., 1934, The life of Great Salt Lake with special

reference to the algae (unpublished thesis in files of Utah

Univ.), May.

———— 1936, Some diatoms of Great Salt Lake: Torrey Bot. 

Club Bull., vol. 63, pp. 157-166.

Lawson, A. C., 1915, The epigene profiles of the desert: California Univ., Dept. Geol. Sci. Bull., vol. 9, pp. 23-48.

Lee, W. T., 1915, Guidebook of the western United States, Part 

B, The overland route, with a side trip to Yellowstone 

Park: U. S. Geol. Survey Bull. 612.

Leggette, R. M., and Taylor, G. H., 1932, Ground-water supplies 

in the vicinity of Salt Lake City, Utah: U. S. Dept. Interior 

Press Mem. 64395, July 23.

———— 1937, Geology and ground-water resources of Ogden

Valley, Utah: U. S. Geol. Survey Water-Supply Paper

796-D. 

Leighton, M. M., 1931, The Peorian loess and the classification

of the glacial drift sheets of the Mississippi Valley: Jour.

Geology, vol. 39, pp. 45-53. 

Leverett, Frank, 1910, The comparison of the North American

and European glacial deposits: Zeitschr. Gletscherkunde,

vol. 4, pp. 241-295, 321-342. 

Lockerbie, C. W., 1942, Bird life about Great Salt Lake: Utah

Min. Soc. News Bull., vol. 3, no. 2, pp. 64-66. 

Marbut, C. F., 1935, Soils of the United States: U. S. Dept,

Agr., Atlas Am. Agr., pt. 3. 

Marsell, R. E., 1931, Salient geological features of the Traverse

Mountains, Utah: Utah Acad. Sci. Proc., vol. 8, pp. 106-

110.
GEOLOGY OF NORTHERN UTAH VALLEY, UTAH 95

Martin, Gail, 1938, Sodium sulphate from the shore of Great

Salt Lake: Eng. and Min. Jour., vol. 139, p. 55, June. 

Mathews, A. A. L., 1930, Origin and growth of the Great Salt

Lake oolites: Jour. Geology, vol. 38, pp. 633-642. 

Maxey, G. B., 1946, Geology of part of the Pavant Range,

Millard County, Utah: Am. Jour. Sci., vol. 244, pp. 324-

356. 

Meinzer, O. E., 1922, Map of the Pleistocene lakes of the Basin

and Range province and its significance: Geol. Soc. America

Bull., vol. 33, pp. 541-552. 

Mendenhall, W. C., 1920, Memorial of Grove Karl Gilbert;

Geol. Soc. America Bull., vol. 31, pp. 26-64. 

Merriam, J. C., 1918, Evidence of mammalian paleontology

relating to the age of Lake Lahontan: California Univ.

Press, 321 pp., Berkeley. 

Moscheles, J., 1922, Der Lake Bonneville und das eiszeitliche

Kilma: Zeitschr, Gletscherkunde, Band 12, Heft 3-4, pp.

166-167. 

Nelson, J. W., and Eckmann, E. C., 1913, Soil survey of the

Cache Valley area, Utah: U. S. Dept. Agr., Bur. Soils. 

Nolan, T. B., 1927, Potash brines in the Great Salt Lake desert,

Utah: U. S. Geol. Survey Bull. 795-B.

———— 1935, The Gold Hill mining district, Utah: U. S. Geol.

Survey Prof. Paper 177. 

Pack, F. J., 1926, New discoveries relating to the Wasatch fault:

Am. Jour. Sci., 5th ser., vol. 11, pp. 399-410. 

Packard, A. S., Jr., 1873, Insects inhabiting Great Salt Lake and

other saline and alkaline lakes in the West: U. S. Geol. and

Geog. Survey Terr. 6th Ann. Rept., (Hayden), pp. 744-748.

———— 1876, On the supposed ancient outlet of Great Salt Lake: 

U. S. Geol. and Geog. Survey Terr. (Hayden) Bull. 5, pt. 

2, pp. 413-414.

———— 1876a, The Great Salt Lake in former times: Am. 

Naturalist, vol. 10, pp. 675-681.

1879, The sea weeds of Great Salt Lake: Am. Naturalist,

vol. 13, pp. 701-703. 

Paul, J. H., and Baker, F. S., 1925, The floods of 1923 in northern

Utah: Utah Univ. Bull., vol. 15, no. 3, March. 

Powell, J. W., 1879, Lands of the arid region of the United

States: U. S. Geog. and Geol. Survey Rocky Mtn. Region

Rept., (Powell), p. 124. 

Rees, D. M., 19.42, Animals living in, the Great Salt Lake: Utah

Min. Soc. News Bull., vol. 3, no. 2, pp. 57-58. 

Reynolds, R. V. R., 1911, Grazing and floods—a study of conditions in the Manti National Forest, Utah: U. S. Forest

Service Bull. 91. 

Richardson, G. B., 1905, Natural gas near Salt Lake City: U. S.

Geol. Survey Bull. 260, pp. 480-483.

———— 1906, Underground water in the valleys of Utah Lake

and Jordan River, Utah: U. S. Geol. Survey Water-Supply

Paper 157, pp. 36, 50, 51, 5^-75. 

Rower, A. S., 1928, A "fossil" camel recently living in Utah:

Science, M. Sec., vol. 68, pp. 19-20. 

Russell, I. C., 1876, On the formation of lakes: Pop. Sci. Monthly

vol. 9, pp. 539-546.

———— 1883, Play as and playa lakes: Pop. Sci. Monthly, vol. 

22, pp. 380-383.

———— 1883a, Sketch of the geological history of Lake Lahontan, 

a Quaternary lake of northwestern Nevada: U. S. Geol. 

Survey 3d Ann. Rept., pp. 189-235.

———— 1884, Lakes of the Great Basin: Science, new ser., vol. 

3, pp. 322-323.

———— 1885, Geological history of Lake Lahontan, a Quaternary 

Lake of northwestern Nevada: U. S. Geol. Survey Mon. 11.

Russell, I. C. 1889, Quaternary history of Mono Valley, Calif.: 

U. S. Geol. Survey 8th Ann. Rept., pp. 261-394.

———— 1895, Lakes of North America, Ginn & Co., Boston, 125 pp.

———— 1895a, Present and extinct lakes of Nevada: Nat. Geog.

Soc., Nat. Geog. Mon. 1, no. 4, pp. 101-136. 

Sanchez, A. M., 1904, Soil survey of the Provo area, Utah: U. S.

Dept. Agr., Bur. Soils field operations, 1903, pp. 11, 12,15,17 

Schneider, Hyrum, 1925, A discussion of certain geologic features

of the Wasatch Mountains: Jour. Geology, vol. 33, pp.

28-48. 

Shantz, H. L., and Zon, R., 1924, Natural vegetation: U. S.

Dept. Agr. Atlas Am. Agr. 

Sharp, R. P., 1938, Pleistocene glaciation in the Ruby-East

Humboldt Range, northeastern Nevada: Jour. Geomorphology, vol. 1, no. 4, pp. 296-323.

—;——- 1939, The Miocene Humboldt formation in northeastern

Nevada: Jour. Geology, vol. 47, no. 2, pp. 133-160. 

Shelley, G. F., 1945, Early history of American Fork; American

Fork City. 152 pp.

Shenon, P. J., 1935, Utah earthquake of March 24, 1934 (abstract) : Washington Acad. Sci. Jour., vol. 25, pp. 508-509. 

Smith, E. R., 1942, Early man in the Great Salt Lake area:

Utah Min. Soc. News Bull., vol. 3, no. 2, pp. 27-32. 

Spieker, E. M., 1946, Late Mesozoic and early Cenozoic history

of central Utah: U. S. Geol. Survey Prof. Paper 205-D,

pp. 149-155. 

Spieker, E. M., and Billings, M. P., 1940, Glaciation in the

Wasatch Plateau, Utah: Geol. Soc. America Bull., vol. 51,

pp. 1173-1197. 

Spurr, J. E., 1901, Origin and structure of the Basin Ranges:

Geol. Soc. America Bull., vol. 12, pp. 217-270. 

Stansbury, Howard, 1852, Exploration and survey of the valley

of the Great Salt Lake of Utah: Congressional documents

32d Cong., special sess., S. Doc. 3, March. 

Steward, J. H., 1933, Archaeological problems of the northern

periphery of the Southwest: Mus. Northern Arizona Mus.

Notes, vol. 5.

———— 1933a, Early inhabitants of western Utah, Part 1, Mounds 

and house types: Utah Univ. Bull. 23, no. 7.

———— 1936 Pueblo material culture in western Utah: Univ. 

New Mex. Bull. 287, Anthropol. Ser., vol. 1.

1937, Ancient caves of the Great Salt Lake region:

Smithsonian Inst, Bur. Am. Ethnology Bull. 116. 

Stokes, W. L., and Hansen, G. H., 1937, Two Pleistocene

musk-oxen from Utah: Utah Acad. Sci. Proc., vol. 14, pp.

63-65. 

Stover, A. P., 1903, Irrigation in Utah Lake drainage system,

in Report of irrigation investigations in Utah: U. S. Dept.

Agr. Bull. 124, pp. 93, 107-144, 134, 135. 

Strahorn, A. T., Stucki, H., and Jennings, D. S., 1922, Soil

survey of the Delta area, Utah: U. S. Dept. Agr., Bur.

Soils Field operations for 1919. 

Stratton G. M., 1929, Utah's salt industry: Utah Eng, vol. 3,

no. 5, pp. 1-3. 

Surface-water reports of the United States, 1914-47, Part 10,

The Great Basin: U. S. Geol. Survey Water-Supply Papers

for the years 1914-47. 

Talmage, J. E., 1896, The Great Salt Lake, past and present:

Utah Univ. Quart. 2, pp. 73-82, 137-152. 

Taylor, G. H., 1937, Ground water in Utah: Am. Geophys.

Union Trans., 18th Ann. Meeting, pt. 2, pp. 536-541. 

Taylor, G. H., and Thomas, H. E., 1937, Ground water in the

vicinity of Woods Cross, Davis County, Utah, (manuscript

report in files of U. S. Geol. Survey).
96 LAKE BONNEVILLE

Taylor, G. H., and Thomas, H. E., 1939, Artesian water levels and 

interference between artesian wells in the vicinity of Lehi, 

Utah: U. S. Geol. Survey Water-Supply Paper 836-C, pp. 

107-156.

Teele, R. P., 1903, Irrigation from Jordan River, in Report of 

irrigation investigations in Utah: U. S. Dept. Agr. Exper. 

Sta. Bull. 124, p. 80.

Thomas, H. E., 1946, Ground water in Tooele Valley, Utah: 

Utah State Eng. 25th Bienn. Rept., pp. 116-118.

———— 1952, Utah Valley, in Status of development of selected

ground-water basins in Utah: Utah State Eng. Tech. Pub.

7, pp. 71-76. 

Thomas, H. E., and Nelson, W. B., 1948, Ground water in the

East Shore area, Utah; Part 1, Bountiful district, Davis

County: Utah State Eng. Tech. Pub. 5, Utah State Eng.

26th Bienn. Kept., pp. 59-206. 

Thomas, O. D., 1937, Salt in the valley of the Great Salt Lake:

Compass, vol. 17, no. 3, pp. 163-166. 

United States Geological Survey, 1916, Potash in lake muds

of western Utah: Press Bull. 271, May.

———— 1947, Surface water supply of the United States 1945, 

Part 10, The Great Basin: U. S. Geol. Survey Water Supply 

Paper 1040.

Utah Agricultural Experiment Station, 1945 (?), Land classification map, Utah and Goshen Valleys, Utah County.

Utah State Agricultural College Experiment Station, 1931, 

Report of special flood commission appointed by Gov. 

G. H. Bern, Circ. 92.

Varnes, D. J., and Van Horn, R., 1951, Surficial geology of the 

Oak City area, Millard County, Utah: Unpublished manuscript in files of U. S. Geol. Survey.

Vorhies, C. T., 1917, Notes on the fauna of Great Salt Lake:

Am. Naturalist, vol. 51, p. 494. 

Watson, H. J., Gardner, D. I., and Harding, S. T., 1941, Records

of measurements of surface flow to Utah Lake and Provo

Bay: in Board of Canal Presidents of Associated Canals

Rept. 8 (unpublished), tables 5-8. 

Wheeler, G. M., 1876, Geological atlas projected to illustrate

geographical exploration and surveys west of the 100th

meridian. Gilbert, G. K., Marvine, A. R., and Howell,

E. E., sheet 12, Restored outline of Lake Bonneville,

Utah and Nevada. 

Williams, J. S., 1948, Geology of the Paleozoic rocks, Logan

quadrangle, Utah: Geol. Soc. America Bull., vol. 59, no. 11,

pp. 1121-1163. 

Wilmarth, M. G., 1938, Lexicon of geologic names of the United

States: U. S. Geol. Survey Bull. 896, p. 1897. 

Woolley, R. R., 1924, Water powers of the Great Salt Lake basin:

U. S. Geol. Survey Water-Supply Paper 517.

———— 1927, Some salient features connected with the fluctuations in level of Great Salt Lake: Utah Eng., vol. 1, no. 8, 

pp. 1-3.

———— 1944, An engineer looks at Great Salt Lake: Civil Eng., 

vol. 14, pp. 332-334, New York.

1946, Cloudburst floods in Utah, 1850-1938: U. S. Geol.

Survey Water-Supply Paper 994.

Woolley, R. R., and Alter, J. C., 1938, Precipitation and vegetation: Am. Geophys. Union Trans., pp. 604-607.

ZoBell, C. E., Anderson, D. Q., and Smith, W. W., 1937, The 

bacteriostatic and bactericidal action of Great Salt Lake 

water: Jour. Bacteriology, vol. 33, pp. 253-262.
INDEX

Page 

Abstract.—--.------------...--------.-.._....._____................. 1-2

Acknowledgments__._________________________.. 2,4

Alluvial deposits, ground water In________________________ 80-82 

of Provo age..___________________________________ 28-29 

of Quaternary age.---—.----_—............_-_....._............ 12

properties of...———._.__________________._____ 52

Alluvial-fan deposits, properties of.______________________.. 52

uses of......................................_....__................... 57

Alluvium, mechanical analysis of________________________ 29 

pollution of water in.________________. _____________ 80-81 

recharge area for ground water In..________________._. 80 

water table In..________________.________.__...... 80

Almond, Hy, colormetric tests by...._______________...__.... 34

Alpine formation, chemical analyses of.._____________.__ 31,32,33,34 

comparison with Provo formation..._____________„_.__.. 33-34 

description-..-------....-.-.---.---.----.....----.._................. 17-20

volume of...._________.________._______________ 37,40

water-bearing properties of..._________________________ 81-82 

American Fork River....————-—— 6,7-8,24,28,29,S&-37,42,52,60-61,67,68

Aquifers—.—————.——— —.....—.„..... ——...................... 17,83-89

Atwood, W. W., quoted.______...__________________.__„ 27

B 

Base course materials_ — _--.-.._______________-. 53,56,57-58

Battle Creek...—— —— —— —— —————————————————— 60-61,67,68

Bench gravel, properties of.. __. __.____________________ 49

uses of___.________...______________________ 53-56 

Bibliography. ————-———-.. —— ———————————— —— — —— 92-96

Bonneville formation, description..._.____________________ 20-21

volume of.._.________._______________________ 37 

Brannock, W. W., analyses by-....———.—........... — ................ 31

C

Calcareous tufa. 

Calotte..———

————————.....———————————————————— 60

———.-————.—————————————————— 60

Calcium bicarbonate in water....._________________.____ 89-90

Calcium carbonate deposits—- _______________________ 35-36,89 

Canal lining, material for_______-___________________... 58 

Chemical analyses of water. __.________________________ 88 

Clarke, F. W., quoted._. —— —— ...-.——_.__„__................. 32,34

Clay, analyses of___..__._..__.____________________ 20,59 

chemical analyses of.__.__________._____________ 31,33-34 

mechanical analysis of.__.---.._______________.____. 24 

of the Alpine formation.._-------______________.....__ 20

of the Provo formation._......_._____________..._-. 24-25

uses of...——...__,_._...._______________________ 58-59

Climate, description.—————..——.———.——„..—_—.—..... 8-11,17

evolution of—________________________________ 42 

Colluvial cones.--__._________________.________...... 12

Concrete aggregate, materials for._____________________ 53,56,57-58 

Construction materials, processed, description.___________-....-.. 58-60

unprocessed, description_____._____________________ 53-58 

Cox, Jacob, well of....—...———.......„........„......„....———...... 76

Davidson, Norman, analysis by._______________________.. 31 

Deer Creek reservoir, description_.. —..__________________. 66 

Deer Creek reservoir, water loss from...___.___________.__... 73 

Delta deposits-----...——————————.__-_-__...._.„...—. 21-24

Differential head of aquifers.. _____________________.__.. 87,89 

Diversions from streams, prior to 1880...._____________________ 61-62

status in 1903.--------.---.--_——_.___-__........_.....— 62-63

statusinl947.—-————- —————.......—————.................... 63

Drains, description of.....____________________________ 78

Drought Relief Administration, well of _____________________— 26,76 

Droughts—— — — —— ——— .-.. ——— ——————————.—.—— 69,71,77-78

DryCreek..- ——. — .-.———————————.—............ 7-8,36-37,42,52,68

E

Pag

Earthquakes,._—__—..—————————————————.———————— 60 

Engineering geology by Helen D. Varnes.——————————————————— 47-60 

Eollansilt—...._-___-__—_....————.——.... ———.——— 29 

Erosion, geologic aspects of..—————————————————————————— 46-47

rate of— -----—-...———.—.......———-—.———.--.—.—....—— 43

Evaporation, computation of..————————————————————————— 69-71

table showing___— —.— —— - — — - —————— — --——————— 10 

Evolution of Utah Valley——————————————————— 42-43

Fanglomerate deposits——_——_———-——————————————— 14-15,42,57 

Farming.________^... __—_————...——.——————————— 5

Faults———---—-—————--—————————- — -————— 38-39

Field work..__..._——_——_—————————————————————— 4-5 

Fill, materials for..——————————————————————— 53,56,57-58

Flood control, geologic aspects of._....—-——.—————————————— 46-47

Flowing wells, deep aquifer for.....—————————————-————————— 84

early development of..__...-__——....—_——.—————————— 63-64

fluctuation in artesian pressure in..... ———————— — ——— — ———— — 77

number of_—_..—.-..——.. — -....-——.—— — — ——————— 64

shallow aquifer for_—__.-__—————.——— ————————.. 83

Fluctuations in water supply..——.—————————————————————— 66-79 

Fossils—.——————————————————————— 13,20,21,22,23-24,29

Foster, Margaret D., chemical analysis by..———————— ————.——— 32

Foundation materials, bench gravel__————...—...—————————— 49

consolidated rocks..———————————————————-———————— 52-53

mixed gravel and sand...__.__——.——...——.—————————— 50 

properties affecting. -------———————————————————————— 48-49

river gravel.——.———...————————————————————————— 49-50 

sand..-——————— ——————————————————————— 50

silt and clay..———————————————————————— 50-52

unsorted materials——-———..————————————————————— 52 

Fugal Springs..____—__—__———.——————-————————— 78 

Fulton decree—--------------_—-_———————————.——— 62

Fur hunters..———.—————————————————————.————————— 6

G 

Qastropodshells————————————————————— 13,22,23,24

Geneva Steel Co., reservoir of__——————————————————————— 66 

water used by...— ————————————————— ——————————— 91-92 

wellof————————————— ———————————— 16,76,85-87

Geochemical studies.-...--.——.—....—————.————-————— 31-36

Geography, economic———————————— ————————— - —————— — 5-6 

physical..——————————————— ——— -——-———————- 6-11

Geologicalhistory..——————————————————————— 39-43

Geologic time, estimate of....—————————————————————————— 43

GDbert, G. K., quoted..———.—————...————.————-—-—-——— 15,35 

Glacialdeposits—.————————————————————— 12,27-28

Glacial lake deposits...——.———————.—————————————— 15-17

GJacial outwash.....————————————————————— — — —————— 28

GoshenBay—-—-——————————————————————90-91

Gravel, map of deposits....—————————————————-————————— 55

mechanical analysis of————.————————————-————————— 22 

of the Alpine formation..._......————————————————————— 17-18

of the Provo formation__——...——.——.————...———————— 21-22 

See oZso bench gravel, gravel and sand.

Gravel and sand, mixed, properties of..———————————————————— 50

mixed, uses of._——— ———————.. ——— ——— - — ———————— 56

Ground water, sources of..——————————————————————————— 79-89

Ground-water districts—. ——— ———————————————— -———————— 64

H 

Hansen, G. H., quoted......————.-..——.——————————.„-—— 21

Hardness of water, table of...————————————————————————— 87 

Head of the water, measurement of.—————————————————————— 87,89 

Heavy metals, traces of.————————————————————————————— 34 

Highland bench— —— ———.———_——___- 7-8,21-23,28,35,50-51,57,81

97
98 INDEX

Page

Highland ground-water district__--__——_—_—_—_______ 64

History, geological—.----..——.————————————————————————— 39-44

structural-.-.——.——-————————————————————.——„—— 39-40

Huff, Lyman, colorhnetric tests by.——-——————————.—.._.__._ 34

Hunt, Charles B., General geology._.—.—————————.——.——_..-. 11-47

Hydraulic characteristics of aQuifiers, determination of.._—————————— 91

Hydrographs, of discharge from springs.———————————————————— 79

of streams...—_——_————————————————————.————— 68

of wells___ - __ - ___ - __——-———-——-——-——______ 76

Indians—————— 

Indus try...————. 

Inflow, estimates of. 

Introduction.. _.—

Jacobsonand Smith, well of.___...._—_—_.____________ 26 

Jordan River.-----.—.....——.——..———.———————.———..... 6,7,60-61

Lake Bonneville, age of——————————————————.——..————— 41-42 

index map of... — — — ———————..—————————————————— 3

salinity of_.. — -...-——...——.—————„_.A._.............. 34-35

size of_------—--..——.-———————————————————..————-. 17

Lake Bonneville group, description-—————————————————————— 17-25

water-bearing properties of__—————————————————.————— 81-82

Lake deposits.-------————————————————————.——.—--..—— 29,58

Lake ground-water district—.-———————————————————..————— 64 

Lake monument, altitude of.--———————————————.——...-__.... 65

Lake Mountains.—--——.———————————————————————..—— 8,12 

Lake silt and clay, uses of._————————————————._—————..—— 58 

Landforms—— ._ — — — — — — — - — — — — .— ————__—_______..... 6-8

Lava-- — —— — -————— —— ————— — - — ——-.———- —— —— 12

Lehi Irrigation Co., well of. 

Limestone for flux____-- 

Little Cottonwood stock....

M

Mammoth———______-_-_...__..._.__..____________ 21,29 

Mapping, methods used in...___.______________________ 4-5 

Mesozoic rocks...____._________. _________________ 11-12 

Mineral content of water, table of._.. _______________..... 87

Mollusks, in the Provo formation_—_—......__.__________ 25

Moraines__._...____.___.__..._..._______________ 26 

Mormon settlers..........__.._——_—_...________..___... 6

Morse, Hon. C. W., quoted.-._________._______________ 63 

Morse decree.________.—..„......—_.___..____._____ 62,63

Movement of ground water......______._________._ 80,81,83,85,87-88,89

N

Natural discharge from aquifers.._..__ — _—__..________._.. 83,85 

Natural losses of water..—.___._____....._________._____ 90-92 

Near-shore deposits, comparison with offshore deposits....._..........._ 33-34

Offshore deposits, comparisons with near-shore deposits_ _____.._... 33-34 

Orem, log of city well for..._____.__.......___________._._ 26-27

Orembench.-.. ——-..-..———. —— ..-- ——— ...—— 6,8,21-23,35,50-51,57,81 

Ostracodes—--. — — ._.. — — — ._. ... — .._.__.. —.__.___... 20.23-25

Paleozoic rocks. —......— . — — .....-..__..._..._._._______._ 11,53,57-58

Peat.—— ———-- ——- —— .———- — -- —— —— - — —— -. — —— — 15

Piezometric surface, of the deep aquifer. ___.____.______—....—. 84

of the shallow aquifer— — . ——. — — _----..-.---.--_..___„...__. 83 

Pollution, of ground water...........---__.....__________.__.._. 80-81

tests for._.....____..___......_—_.—— — __________.... 81

Population_.....__......_.__..____....__.__.__...._...... 5

Pre-Cambrianrocks.. —----_ — — .-..-.-_...._._____.._........... 11

Precipitation, at Heber, chart of__-______.___________.....__ 70

tables showing___---------_.-.._..._____________..... 9,10

Pre-Lake Bonneville Pleistocene deposits, description....... ___........... 14-17

water-bearing properties__.__.__________.___.__._.._ 82-85 

Previous studies......._..._._..__.________.____.____ 5

Priorities for water. — .__....._.______._____._____....„. 61-63

Provo Bay...— ——..-_.. — .._.._____________.....__.___.... 90-91

Page 

Provo formation, chemical analyses of_________....._____ 31,32,33,34

comparison of similar deposits..-______.._-..._---------------- 32

comparisons with Alpine formation_—_ — --------———.... — — 33-34

description of_______.__——— —......-..-.. —. — —— — — —.— 21-25

volume of__..--_.__-______..——........——— —— —. —...... 37,41

water-bearing properties of— — .———.——— — ——— — —————— -—— 81-82

water-soluble salts in---------...----..———————— — —— —— — — 32,33-34

Provo ground-water district--------———— — —— — _ —— ---------- —...... 64

Provo River.......-————————————— 7,29,36-37,42,52,60-61,66,67-«8,69

Provo River project—________ ———. ——...—————————— — — 90-91

Q 

Qualityof water....—..————.--————— — —— ------ —----- 89-90

Quarries for gravel and sand, map..———-—_———_—__ ———------------ 54

Quaternary deposits in the mountains————————_ —. —_ —__ —— —.. 12

R 

Recharge area, for ground water.._..._— — _—------_........... 80,81,84-85

in alluvial deposits..-__...„„ ——.——.—...——.. ——— — „-.- — . 80

of aquifers...---_——————————————————————- ————— -—— 89

Reservoir control. —— ————— —————————————— ——————————— 65-66

Reservoirs..---.---------------.-------——————————————————— 69-73

Riprap, materials for...———————————————————————————— 53,56,57,58 

River gravel, properties of..........._..._...——————————————— 49-50

uses of_-———--------_.---_----------_—-...—...-----.------.--. 56

Rocks, for foundation materials, properties of.————.———————————— 52-53

S

Salt Lake formation, description of_—_—__ ___.__.__.._.— 13-14

volume of._———————————————————————————————— 37

Salvage of water——————————. ————————————— ———————— — 92

Sand, mechanical analysis of_—————.————————————————.— 22,23

of the Alpine formation... ——_—....„_—__——..——_..__— 18-20

of the Provo formation..._._.__.__.______________... 22-23

properties of————————————————————————. ———————— 50

uses of..———————————————————————————————————— 57

Sand bars._———————————————————————————————————— 23

Saratoga Springs_————————————————————————————————--— 79,89

Sedimentation, history of—_——.—————.—...—....——......_— 40-41

Shale, Paleozic.------————————————————-——————.——----- 58

uses of—————-—————————————————————————————— 58

Silt, chemical analyses of...-———————————-————————.—— 31,33-34 

mechanical analysis of...————————————————————————————— 23 

of the Provo formation_...._—...—......__—______.__— 23-24

Silt and clay, lake deposits of.——————————————.—.—————.—.. 58 

of the Alpine formation_——.—_——..—....—__—__......— 20

properties of———————————————.————.——.———.——-— 50-52 

uses of.... ——— ——————————————————————————————— 57

Soil genesis, factors of_———————————————————— ————— ——— 45-46 

Soil profile, depth of—.—————.—————————.....———————-..— 46

Soils, ancient.——————————————————.................. 43-45,58-59

evolution of——..————————————————————————-——-— 42-43 

modern_----- ————————————————————— ——————————— — 45

.————————————_———————————————_•- 45

Source rocks.-—————————— ———————————— ——————————— —— 11-13

South Fork Provo River.——.—.—————————-... — „——..——....—— 67,68

Spanish explorers-—————————————————————- ————————— ------ 6

Springs, discharge of..————————————.———-----------——.—....— 78-79

in Utah Lake.-————————————————— — .—————- 72

Stover, A. P., quoted.....—————————————————————.——.——-— 61,62

Stratigraphic sections———————————————————————————————— 1,11 

Stratigraphy—-.--—---.—.————————————.—.—...——-———... 11-46 

Stream discharge, records of._~———————————————.—————.... 67-68

Streams, fluctuation in water of__———.————————_..—.———— 66-69 

hydrographs of flow.... —————————————————— ————————... 68

inlltah Valley..————————_———————— 60-61,66-69

Structure-—--------——————.———————————.—————.——.. 38-39

Subsurface inflow to Utah Lake..————————————————————————— 72 

Surface inflow, records of...————.——.———————————-——-— 71-72

Surfacing materials ___- __—__—__—__—__ - ________ 53,56,57-58 

Swain, F. M., quoted-------——-——-——-———-----——.—-----—— 24,25

T 

Talus cones —...——.———————————————„.——.—...——-— 12

Tertiary deposits, water-bearing properties-———.....——.——.—...— 85-89 

Tertiary rocks————__„__....____..___————— 12,13-14,52-53,57 

Thomas, H. E., Water resources..————.—__..._.__...__..._„ 60-90
INDEX 99

Page

Topography, evolution of-_ __________________________ 42

Towns-..--.....——-.___________________.____________ 5,6

Transportation__________________________________ 5,6

Traverse Mountains______________________________ 8,12

Travertine. See calcareous tufa-...______________________ 60

Tuff—... -————.... —— —————————————————————— 12

U

Union Pacific Railroad, well of _. _ _______________________ 13-14 

Utah Lake, areaof._______________________________ 65 

capacity of.__...._____________________________ 65 

chemical analysis of water from. ______________________ 32 

description of---________________________________ 6-7 

diversions from.- _____________________________ 65-66,90 

evaporation from.-. — ___________________________ 10,71 

inflow and outflow_____ ___________________________ 69-71 

natural losses of water-...__________________________ 90-91 

salinity of ———. _________________________________ 34,35 

springs in——————_..._....____________________ 72 

subsurface inflow, ______________________________ 72 

surface inflow into.__.___________________________ 71 

Utah Valley, description of. ___________________________ 6-7 

origin of..___—..._____________________________-. 39 

stratigraphic section of...._...______________________ 1 

structural geology of.--,-..__________—_.___________ 38-39

Valley flil, depth of —— - — — .———.._............—...——..—..... 37-38

Valley sediments, relation to source rock.__ _________________ 12-13 

Varnes, Helen D., Engineering geology.___________________.. 47-60 

Vertebrate fossfls.____-----_______—.._...............__ 21,23,24,29

Volumes of the formations, comparison of- _________._.________ 36-37

W

Wasatch Range, description. 

stratigraphic section of—.

Page 

Water, chemical quality of_——— ————————————— ———————— 89-90

temperature of———————————————————————————————— 89 

Water level, fluctuations of, long term.. ——————————————.————— 77-78 

• fluctuations of, seasonal——————————————————————————— 77 

Water resources by Harold E. Thomas.....————————-—-—-—...— 60-90

maximum potential development of.———————————————————— 90-92 

Water rights, diligence rights...———————......———.——...——..— 62-63

laws concerning—.———————————————————————————— 61-62,90 

Water-soluble salts, analyses of—........————————————— 32,33-34

Water supply, fluctuations, in reservoirs.———————————————————— 69-73

fluctuations, in streams———„——.———————————————————— 66-69

Water table—————————————————————————— 80,81

Water utilization, history of—————...—————...———.......... 61-66

Weathering, factors controlling- —————————————————— -————— 46 

Weber River...__......__————————————————————— 69

Well discharge, relation to fluctuation of water levels.....—————————— 78

total.———————————————————--———————- 78

Well logs...--—_———————————————————————— 13-14,26-27

Well-numbering system.————— —————————— ————————————— 25 

Well records, collection of _——.——————————— — —————————— 61 

Wells, classification of------——————————————————————————— 64

discharge of.--———————————————————————————————— 73-75 

discharge of, from deep sources..- ——————————————— ————— 89 

discharge test of— — —————————————————————— 86-87

drawdown test——————— ———————————————— — — - —— — • 86

early development of-.... — — ——————————— —————— ————— -- 63-64

fluctuations in artesian pressure.————.———— ————————— ——— 77 

fluctuations in water level-...———————————————————————— 76-77 

long-term fluctuations in.———.——————————————————————— 77-78 

number of, by years.. ———————————————— ——————————— — 65 

status of, in 1903__.___-_—..„——.————...—.....————- 64

status of, in 1947———————————-—-—-——-———— 64-65

yield of, in Highland district.————————————-——— ————— 73-74

in Provo district——————————————————————————————— . 75

Yen, Teng-Chien, quoted—-.- — — ————— — --- — . — —— — — — -- 23.25

o