U.S. Department of the Interior

U.S. Geological Survey

Professional Paper 1764

Mid-Permian Phosphoria Sea in Nevada and the 

Upwelling Model

Mid-Permian Phosphoria Sea in Nevada 

and the Upwelling Model

By Keith B. Ketner

Professional Paper 1764

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2009

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Suggested citation:

Ketner, Keith B., 2009, Mid-Permian Phosphoria Sea in Nevada and the upwelling model: U.S. Geological Survey 

Professional Paper 1764, 21 p.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

The Upwelling Model ...................................................................................................................................1

Stratigraphy and Definitions ........................................................................................................................3

Shallow Marine Deposits of the Phosphoria Sea in Nevada .................................................................3

Northern and Central Nevada ............................................................................................................3

1. Leach Mountains..................................................................................................................3

2. Southern Pequop Mountains ............................................................................................3

3. Ferber Hills ............................................................................................................................4

4. Confusion Range .................................................................................................................4

5. Elk Mountain ........................................................................................................................5

6. Northern Snake Mountains ...............................................................................................5

7. Southern Snake Mountains................................................................................................5

8. Medicine Range ...................................................................................................................6

9. Butte Mountains...................................................................................................................6

10. Mount Ichabod .....................................................................................................................6

11. Dorsey Canyon–Divide Peak ..............................................................................................6

12. Northern Adobe Range .......................................................................................................7

13. Peko Hills .............................................................................................................................10

14. Southern Adobe Range ....................................................................................................11

15. Southern Piñon Range ......................................................................................................11

16. Edna Mountain ...................................................................................................................11

17. Monitor Range....................................................................................................................12

18. Southern Toiyabe Range...................................................................................................12

19. Southern Toquima Range..................................................................................................12

20. Candelaria Hills...................................................................................................................12

Southern Nevada ...............................................................................................................................13

The Allochthonous Havallah Sequence..........................................................................................14

21. Battle Mountain .................................................................................................................14

22. Southern Shoshone Range...............................................................................................14

23. Northern Toiyabe Range ...................................................................................................15

Western Correlatives of the Havallah Sequence..........................................................................15

24. Northern Hot Springs Range............................................................................................15

25. Northern East Range ........................................................................................................16

Correlatives of the Phosphoria Formation in Terranes Thought to be Accretionary ..............16

26. Quinn River Crossing .........................................................................................................16

27. Pine Forest Range ..........................................................................................................16

Conclusions...................................................................................................................................................16

The Phosphoria Sea and Its Sediments in Nevada.......................................................................16

Pennsylvanian and Permian Strata Underlying Sediments of the Phosphoria Sea 

in Nevada ...............................................................................................................................17

The Phosphate Content of Phosphoria-age Sediments in Nevada............................................17
iv

The Western Margin of the Phosphoria Sea..................................................................................17

Phosphoria Formation and the Oceanic Upwelling Model..........................................................17

Acknowledgments.......................................................................................................................................17

References Cited..........................................................................................................................................17

Figures

1. Index map of Nevada, Idaho, and vicinity. ...............................................................................2

2–26. Photographs of:

 2. Leach Mountains, Meade Peak Member; steinkern with part of carbonate 

shell intact ..............................................................................................................................3

 3. Leach Mountains, Meade Peak Member, closely packed pellets with 

interstitial quartz silt and carbonate ..................................................................................4

 4. Ferber Hills, Meade Peak Member, steinkerns and pellets are cemented 

with clear secondary chert..................................................................................................4

 5. Confusion Range, Plympton Formation, dolomite with dispersed crystals 

and rosettes of gypsum........................................................................................................5

 6. Confusion Range, Plympton Formation, minute pellets and masses of 

phosphate in fine-grained dolomite ...................................................................................5

 7. Confusion Range, Plympton Formation, spicule chert with sparse, 

minute phosphate pellets.....................................................................................................5

 8. Mount Ichabod, slightly phosphatic spicule chert in which most of the 

phosphate is in the axial canals of the spicules ..............................................................6

 9. Mount Ichabod, phosphatic sandstone.............................................................................7

 10. Dorsey Canyon, sandstone from unit 2 ..............................................................................7

 11. Northern Adobe Range, lower member, prismatic shell of Atomodesma in 

phosphatic limestone laced with length-slow chalcedony............................................8

 12. Northern Adobe Range, middle member, spicule chert showing dolomite 

rhombs and phosphate (dark brown) in axial canals of spicules..................................8

 13. Northern Adobe Range, top member, phosphatic pellets in siltstone matrix 

of dolomite rhombs, quartz, and spicules..........................................................................8

 14. Northern Adobe Range, top member, small phosphatic steinkerns in slightly 

phosphatic siltstone..............................................................................................................8

 15. Peko Hills, middle unit, central pellet composed largely of spicules with 

interstitial phosphate ..........................................................................................................10

 16. Peko Hills, middle unit, small pellets and ooides in matrix of broken 

spicules and fragments of phosphatic shells .................................................................10

 17. Peko Hills, middle unit, steinkern with phosphate and spicules in a matrix of 

silt-size quartz, spicules, and phosphate ........................................................................10

 18. Peko Hills, middle unit, bed of mainly gypsum and length-slow 

chalcedony among clasts of phosphatic chert and siltstone ......................................11

 19. Southern Adobe Range, irregular phosphate pellets and a steinkern in a 

matrix of angular quartz clasts, spicules, and minute phosphate pellets.................11

 20. Edna Mountain, Edna Mountain Formation, two large clasts of phosphate in 

a matrix of quartz, spiculitic chert, and small phosphate clasts .................................12
v

 21. Edna Mountain Formation, length-slow chalcedony clasts in sandstone, 

here composed mainly of angular chert grains .............................................................12

 22. Candelaria Hills, Diablo Formation, phosphorite mass composed of phosphate 

pellets in a matrix of quartz-silty phosphorite ................................................................13

 23. Candelaria Hills, Diablo Formation ...................................................................................13

 24. Battle Mountain, mid-Permian part of Havallah sequence, small phosphate 

rods and pellets are in chert-cemented quartz silstone...............................................14

 25. Battle Mountain, mid-Permian part of Havallah sequence,phosphate 

pellets are in a matrix mainly of spicules and silt-size quartz and chert grains.......14

 26. Battle Mountain, mid-Permian part of Havallah sequence, phosphatic 

sandstone .............................................................................................................................15

Table

1. Percent P2O5 of samples chosen at arbitrary equal intervals across 

mid-Permian stratigraphic units, northern and southern Adobe Range.............................9

Abstract

The Phosphoria Sea extended at least 500 km westward 

and at least 700 km southwestward from its core area centered 

in southeastern Idaho. Throughout that extent it displayed 

many characteristic features of the core: the same fauna, the 

same unique sedimentary assemblage including phosphate 

in mostly pelletal form, chert composed mainly of sponge 

spicules, and an association with dolomite. Phosphoria-age 

sediments in Nevada display ample evidence of deposition in 

shallow water. The chief difference between the sediments in 

Nevada and those of the core area is the greater admixture of 

sandstone and conglomerate in Nevada. Evidence of the western margin of the Phosphoria Sea where the water deepened 

and began to lose its essential characteristics is located in the 

uppermost part of the Upper Devonian to Permian Havallah 

sequence, which has been displaced tectonically eastward an 

unknown distance. The relatively deep water in which the 

mid-Permian part of the Havallah was deposited was a sea of 

probably restricted east-west width and was floored by a very 

thick sequence of mainly terrigenous sedimentary rocks. The 

phosphate content of mid-Permian strata in western exposures 

tends to be relatively low as a percentage, but the thickness of 

those strata tends to be high. The core area in and near southeastern Idaho where the concentration of phosphate is highest 

was separated from any possible site of upwelling oceanic 

waters by a great expanse of shallow sea.

Introduction

The Phosphoria Formation and its local correlatives, the 

Shedhorn Sandstone, and the Park City Formation, are wellstudied deposits of the mid-Permian Phosphoria Sea centered 

in southeastern Idaho. The northern, eastern, and southeastern 

extensions of the Phosphoria Sea are quite well known, but 

its western and southwestern extent, the nature of its western 

margin, and the nature of its western sediments are commonly 

left to the imagination.

The Upwelling Model 

Many published accounts express the belief that the 

Phosphoria Formation was deposited at the continental margin 

beneath upwelling waters as summarized in the following 

statement authored by several eminent authorities: 

“Comparison with modern phosphorite occurrences 

has led many workers to conclude that most if not all 

ancient phosphorite giants were laid down beneath 

upwelling depocenters. This has remained a particularly attractive scenario, especially for deposits 

that developed, as today, along western continental 

margins (e.g. Permian Phosphoria Formation...)” 

Glenn and others (1994, p. 772).

 Actually, a large body of new and old evidence indicates 

the Phosphoria in its core area was deposited hundreds of 

kilometers from any possible site of oceanic upwelling. Apparently the Phosphoria was not alone in this regard. The following statement regarding the Tethyan phosphate deposits was 

included in the same report by Glenn and others (1994).

“Yet Glenn and Arthur (1988) stressed that upwelled 

waters are rapidly depleted of nutrients, that productivity is greatly diminished within relatively short 

distances of the locus of upwelling, and that some 

of the Tethyan deposits were laid down beneath 

relatively shallow waters that were apparently tens 

to hundreds of kilometers removed from the open 

Tethyan margin to the north.”

Published and unpublished data dispel most of the 

mystery concerning the area west of the depocenter of the 

Phosphoria, (fig. 1) and the present report seeks to bring the 

relevant facts and sources together in a brief outline.The plan 

of the present report is to briefly describe the Permian stratigraphy at several localities in Nevada and to document the 

nature of the mid-Permian phosphatic sediments by means of 

descriptions and illustrations. Some of the localities described 

are known to the author only through published reports, but 

most are known from first-hand observation in the field and 

laboratory. 

Mid-Permian Phosphoria Sea in Nevada and the 

Upwelling Model

By Keith B. Ketner
2 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

CALIFORNIA

NEVADA

ARIZONA

UTAH

IDAHO WYOMING

OREGON

Las Vegas

SALT LAKE CITY

Reno

Elko

Pocatello

Phosphoria

Basin

20

23

15

16

14

12 13

11

10

22

25 21

26 27

24

19

18 17

9

4

3

8

2

1 7

6

5

120° 117° 114° 111°

45°

41°

37°

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

Leach Mountains

Southern Pequop Mountains

Ferber Hills

Confusion Range

Elk Mountain

Northern Snake Mountains

Southern Snake Mountains

Medicine Range

Butte Mountains

Mount Ichabod

Dorsey Canyon–Divide Peak

Northern Adobe Range

Peko Hills

Southern Adobe Range

Southern Piñon Range

Edna Mountain

Monitor Range

Southern Toiyabe Range

Southern Toquima Range

Candelaria Hills

Battle Mountain

Southern Shoshone Range

Northern Toiyabe Range

Northern Hot Springs Range

Northern East Range

Quinn River Crossing

Pine Forest Range

0 50 100 MILES

0 50 100 KILOMETERS

Figure 1. Index map of Nevada, Idaho, and vicinity showing localities to which reference is made, and the 

outline of the core Phosphoria Formation centered on southeastern Idaho (dashed line is boundary between 

organic-rich siltstone and carbonate in the mid-Permian according to Piper and Link, 2002; solid line is the 

outer limit of phosphate according to Sheldon and others, 1967). Both lines project through southern Nevada 

north of the cluster of Kaibab exposures near Las Vegas. Underlined localities (21, 22, 23) are Havallah 

sequence transported eastward on thrust faults.
Shallow Marine Deposits of the Phosphoria Sea in Nevada 3

Stratigraphy and Definitions

The stratigraphic divisions of the Permian proposed by 

McKelvey and others (1959) of Phosphoria, Shedhorn, and 

Park City, and names used in eastern Nevada such as Kaibab, 

Plympton, Murdock Mountain, and Gerster are difficult to 

apply in much of Nevada where local names have long been 

used, and no attempt is made here to regularize the nomenclature. For brevity, in much of the discussion that follows, those 

formations are subsumed under the term mid-Permian strata.

Some terms used in this report are defined as follows: 

mid-Permian is late Leonardian and Guadalupian; Phosphoria 

Sea is the mid-Permian sea in which rocks of the type Phosphoria, Shedhorn, and Park City Formations were deposited. 

Phosphoria Sea is also used in this report for its extension 

westward and southwestward in Nevada where phosphate is 

a significant component of its sediments. The Phosphoria Sea 

thus defined was a small part of a much more extensive largely 

epicontinental sea that extended from Nevada to Kansas and 

Montana to Texas (McKee, Oriel, and others, 1967, plates 

4B and 5B); phosphate is essentially the mineral apatite—or 

more specifically carbonate fluorapatite; phosphorite is a rock 

rich in phosphate; phosphate bloom is the bluish-white sheen 

produced by weathering on the surface of phosphatic rocks; 

steinkern is the phosphatic filling of a small shell; pellet is a 

small ovoid grain of phosphate which may or may not have a 

nucleus of another mineral; length-slow chalcedony is chalcedony with an anomalous optical feature; the slow ray is parallel with the fibers, which was shown to indicate replacement 

of an evaporite mineral (Folk and Pittman, 1971). Because 

length-slow chalcedony has been reported in pelagic deposits, 

however, its presence is not, by itself, evidence for a shallow 

depositional environment (Keene, 1983).

In this report, the Permian rocks at every locality were 

correlated with rocks of the type Phosphoria by means 

of fossils including bivalves and conodonts, backed up 

by observation of stratigraphic position and the unique 

Phosphoria hallmarks of pelletal phosphate and spicule chert. 

They are described in order starting in the northeast and 

ending in the northwest with an excursion to the far south.

Shallow Marine Deposits of the 

Phosphoria Sea in Nevada

Northern and Central Nevada

1. Leach Mountains

The stratigraphic sequence in the Leach Mountains 

includes Permian beds designated, from the base upwards: 

Kaibab Limestone, Meade Peak Phosphatic Shale Member of 

the Phosphoria Formation, Murdock Mountain Formation, and 

Gerster Limestone (Wardlaw and others, 1979). The Meade 

Peak is primarily composed of phosphatic siltstone, chert, 

and shale. The Murdock Mountain is composed principally of 

cherty dolomite and the Gerster is principally cherty bioclastic limestone. According to Martindale (1986), “Deposition 

of the Meade Peak Phosphatic Shale Tongue in the Leach 

Mountains is interpreted to have taken place in very shallow 

water, as based on sedimentary structures and textures, types 

of fossils and their mode of preservation, and the evident 

intertidal to supratidal deposition of underlying and overlying 

rocks.” Thickness of the interval between the Kaibab and 

Gerster is about 1,600 m of which the Meade Peak is about 

100 m. Chemical analyses of 15 randomly selected samples 

of the Meade Peak yielded several in the 1 to 4 percent P2O5

range, one of 19 percent, and one of 28 percent (this report). 

Figures 2 and 3 are samples of phosphatic siltstone from the 

Meade Peak.

2. Southern Pequop Mountains 

The Permian sequence in the southern Pequop Mountains 

overlies Pennsylvanian beds of the Ely Limestone unconformably. From the base upwards, it includes a thick sequence of 

silty, sandy limestone assigned to several formations. The 

overlying mid-Permian strata of the Phosphoria Sea include 

the Kaibab Limestone, the Plympton Formation, and the 

Gerster Formation (Fraser and others, 1986). The Kaibab is 

rich in bioclastic debris and replacement chert nodules. The 

Plympton is principally massively bedded dolomite and dolomitic limestone containing sparse replacement chert nodules. 

Noncarbonate beds of the Plympton include sparse sandy 

beds; phosphatic shale, limy and dolomitic quartz siltstone, 

phosphorite, and chert composed of sponge spicules, of which 

the axial canals are filled with phosphate. Analyses of 12 

random samples of the Plympton yielded nine in the 1 to 10 

percent P2O5 range and three of about 30 percent (this report). 

Figure 2. Leach Mountains, Meade Peak Member; steinkern 

with part of carbonate shell intact. Phosphate pellets and 

steinkerns are in a phosphatic siltstone matrix.
4 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

Many lithic components of the formation contain lengthslow chalcedonic blebs which, according to Folk and Pittman 

(1971), indicate the former presence of evaporite nodules. The 

Plympton is about 350 m in thickness. The Gerster Limestone 

is thick bedded and coarse grained, and contains abundant 

large brachiopods in a matrix of fossil debris with replacement 

chert nodules. 

A persistent breccia occupies a position low in the 

Plympton Formation. This breccia is composed of mainly 

angular fragments of all lithic components of the Plympton. 

Calcite veins and cavity fillings are very abundant and in 

places constitute more than half the volume of the breccia. 

This unit is interpreted to be both a collapse breccia formed 

by the solution of evaporites and a superposed tectonic breccia 

formed by a low-angle fault that tended to coincide with the 

evaporite zone. 

The dolomite, the collapse breccia, and the abundant 

fauna of brachiopods indicate the Permian rocks of the 

southern Pequop Mountains were deposited in a shallow 

marine depositional environment.

3. Ferber Hills

The Ferber Hills are in Nevada near the Utah border. 

Permian strata overlie Pennsylvanian beds of the Ely Limestone. The mid-Permian sequence includes, from the base 

upwards, the Kaibab Formation, the Meade Peak Member of 

the Park City Formation, the Plympton Formation, and the 

Gerster Limestone (Hintze, 1988, Gold Hill section). The 

upper, exposed part of the underlying Arcturus Formation is 

composed mainly of sandstone, siltstone, and dolomite, but a 

minor constituent is gypsum, and collapse features are present, 

indicating the former presence of soluble salts. The Meade 

Peak is abundantly phosphatic, and the Plympton is mostly 

Figure 3. Leach Mountains, Meade Peak Member, closely 

packed pellets with interstitial quartz silt and carbonate.

Figure 4. Ferber Hills, Meade Peak Member, steinkerns and 

pellets are cemented with clear secondary chert.

dolomite with minor bedded chert and phosphatic beds. 

Figure 4 is from the Meade Peak Member.

4. Confusion Range 

The Confusion Range is in Utah near the boundary with 

Nevada. The mid-Permian sequence includes, from the base 

upwards, the Kaibab Limestone, the Plympton Formation, 

and the Gerster Limestone (Hose and Repenning, 1959). 

The underlying Arcturus Formation is mainly interbedded 

sandstone and limestone or dolomite; gypsum is present at 

several horizons, and collapse breccias are prominent in some 

intervals.

The Kaibab is mainly bioclastic detrital limestone 

with chert nodules. According to Hose and Repenning, the 

unit contains sparse phosphate pellets throughout. Fossils 

of the Kaibab include crinoids, echinoids, bryozoans, and 

a brachiopod fauna typical of the Kaibab Limestone of the 

Colorado Plateau (E.D. McKee in Hose and Repenning, 1959). 

The Plympton is approximately equivalent to the Phosphoria Formation and, like the Phosphoria, includes dolomite 

(fig. 5), phosphatic rocks (fig. 6), and spicule chert (fig. 7). 

Hose and Repenning divided the Plympton into five zones. 

These, from base to top, are (1) bedded chert; (2) dolomite; (3) 

chert and dolomite with phosphate pellets; (4) siliceous dolomite; and (5) a mixed unit of dolomite, chert, carbonate breccia, sandstone, siltstone, and gypsum. The Plympton attains a 

thickness of about 200 m in the Confusion Range. 

The Gerster is a very fossiliferous detrital limestone 

with abundant chert nodules and abundant brachiopods 

including the Punctospirifer pulcher fauna characteristic of 

the type Phosphoria and Park City Formations. The faunas 

of the Kaibab and Gerster, listed above, and the dolomite 

and gypsum in the Plympton indicate the mid-Permian rocks 

of the Confusion Range were deposited in a shallow marine 

environment.
Shallow Marine Deposits of the Phosphoria Sea in Nevada 5

Figure 5. Confusion Range, Plympton Formation, dolomite with 

dispersed crystals and rosettes of gypsum.

Figure 6. Confusion Range, Plympton Formation, minute pellets 

and masses of phosphate in fine-grained dolomite.

Figure 7. Confusion Range, Plympton Formation, spicule chert 

with sparse, minute phosphate pellets

5. Elk Mountain 

Collections of brachiopods from this area were reported 

by Coats (1986). The report on one of the collections by 

Mackenzie Gordon, Jr., and B.R. Wardlaw of the U.S. 

Geological Survey stated: “This fauna is Roadian, uppermost 

Lower Permian, and typical of the upper part of the Meade 

Peak Phosphatic Shale Member of the Phosphoria Formation 

in Idaho and Utah.” Two other brachiopod collections from 

the same area confirm that age determination. Although 

little stratigraphic and lithic information is available, the 

brachiopods at this locality indicate a marine environment in 

the mid-Permian.

6. Northern Snake Mountains 

Bezzerides (1967) described the Phosphoria Formation in 

the O’Neil Pass area of the northern Snake Mountains as overlying the Pennsylvanian Oquirrh Formation and underlying the 

Triassic Dinwoody Formation. The Phosphoria here is about 

250 m thick and consists primarily of interbedded siltstone, 

limestone, and chert. Chert interbedded with phosphorite is 

dominant near the top of the formation. The phosphorite is 

described as occurring in beds as much as 0.6 m thick and 

consisting of phosphatic ovules 0.2 to 1.2 mm in diameter. A 

few consist of coated quartz grains, and a few are concentrically laminated. Some of the cement consists of phosphate 

and some is carbonate. A fauna of brachiopods and gastropods 

indicates a mid-Permian age.

Gardner (1968) described similar rocks overlying a thick 

sequence of siltstone 10 km to the southwest. The lower part 

of the Phosphoria here is interbedded phosphatic shale, siltstone, and limestone. The upper part is bedded chert and lesser 

amounts of phosphatic shale, siltstone, and limestone. Dolomite rhombs are scattered throughout. The Phosphoria Formation was estimated to reach a maximum thickness of 335 m. 

According to Mackenzie Gordon, the fauna in the Phosphoria 

at this locality indicates a late Early Permian age (Coats, 

1968). Chemical analyses of 16 randomly selected rocks of 

the Phosphoria Formation indicate a wide variation with 12 of 

them under 2 percent P2

O5 and 4 in the 13 to 34 percent range 

(this report).

7. Southern Snake Mountains

According to Smith and others (1990) the Permian 

sequence that overlies lower Paleozoic rocks unconformably consists of quartz- and chert-grain sandstone and 
6 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

conglomerate composed mainly of chert clasts, overlain by 

siltstone and sandstone containing brachiopods and meandering trails. Brachiopods from the upper part of the unit indicate 

a late Early Permian age (B.R. Wardlaw in Coats, 1968). The 

thickness below the erosional top of the unit is 305 m.

8. Medicine Range

The Permian sequence in the Medicine Range includes a 

thick sequence of siltstone and limestone termed the Arcturus 

Group by Collinson (1968). The overlying mid-Permian 

sequence consists of the Kaibab, Plympton, and Gerster 

Formations. The Plympton Formation, about 150 m thick, was 

described by Collinson as follows: “In the Medicine Range the 

formation can be divided into four lithologic units. The lowest, 

which rests conformably on the Kaibab Formation, is 22 m of 

silty chert.... The second unit comprises about 35 m of lightgray calcareous dolomite which resembles Kaibab dolomite 

but is finer grained. This unit is capped by a bed of chertgranule conglomerate. The third unit, 57 m thick, is predominantly chert, with thin interbeds of fine-grained phosphatic 

dolomite. The uppermost 38 m consists of interbedded dolomite and chert.”

The environmental data are scanty, but dolomite and conglomerate indicate a shallow-water depositional environment 

for part of the mid-Permian. The chert-granule conglomerate 

is typical of other mid-Permian sequences in northern Nevada. 

9. Butte Mountains

The mid-Permian sequence in the Butte Mountains as 

described by Sides (1966) is underlain by about 1,100 m of 

interbedded sandstone and limestone of Early Permian age. 

The mid-Permian rocks were divided into three units: The 

Kaibab Limestone, the Plympton Formation, and the Gerster 

Limestone. The Kaibab consists of about 75 m of dolomite 

and chert and is described as consisting of dolomite of which 

the lower beds “...are locally highly brecciated suggesting 

collapse on solution of underlying evaporites.” Fossils are 

scarce and the age of the Kaibab at this location is uncertain. 

The Plympton consists of about 60 m of dolomite, dolomitic 

limestone, limestone, and chert. Again, fossils are scarce and 

the age of this unit is uncertain from the local evidence. The 

Gerster consists of abundantly fossiliferous limestone, and its 

age, based on a large brachiopod fauna, was determined by 

Sides to be Guadalupian, early Late Permian. The unit is about 

500 m thick in the Butte Mountains. The brecciated dolomite 

interpreted as collapse breccia due to solution of evaporites 

indicates a shallow marine environment of deposition for the 

Plympton, and the abundant brachiopod fauna of the Gerster is 

compatible. 

10. Mount Ichabod

An Upper Pennsylvanian and Permian sequence at Mount 

Ichabod lies with a depositional contact on quartzite of the 

mostly Ordovician Valmy Formation (Ketner and others, 

1996). It consists from the base upwards of conglomerate, 

limestone, siltstone-sandstone, and phosphatic bedded chert. 

Fusulinids from the limestone are of Late Pennsylvanian age. 

The overlying beds are undated locally, but they resemble 

middle Permian beds at other locations. 

Another, mainly clastic, unit is interpreted to be in lowangle fault contact above the Upper Pennsylvanian to Permian 

sequence described in the previous paragraph. This unit is 

composed of conglomerate with clasts ranging from sand 

size to large boulder size. Many of the clasts are composed 

of phosphatic rocks ranging from slightly phosphatic spicule 

chert (fig. 8) to phosphatic sandstone (fig. 9). The large size 

and angularity of these clasts indicate a nearby source. One 

collection of radiolarians from a clast and another from 

chert, thought to be a sedimentary bed rather than a clast, 

were determined to be of Wordian age (early Late Permian, 

Ketner and others, 1996). Conceivably, both are from clasts, 

in which case the conglomeratic unit could be of Triassic age 

but composed of mostly Permian clasts. Whether the unit is 

of Permian or Triassic age, it records the former presence of 

richly phosphatic rock and spiculitic chert typical of midPermian rocks of the region.

11. Dorsey Canyon–Divide Peak

In the Dorsey Canyon–Divide Peak area, the Ordovician 

Valmy Formation and related Silurian beds are overlain 

unconformably by a Permian sequence that consists, from base 

Figure 8. Mount Ichabod, slightly phosphatic spicule chert in 

which most of the phosphate is in the axial canals of the spicules.
Shallow Marine Deposits of the Phosphoria Sea in Nevada 7

rocks in the Dorsey Canyon area are contemporaneous with 

both the Edna Mountain Formation of northwestern Nevada 

and the Phosphoria Formation in its core area.

12. Northern Adobe Range

In its chief exposure in the south limb of the Adobe 

Range syncline, the Permian sequence exposed above a 

low-angle fault consists of three members (Ketner and Ross, 

1990). The lowest member is extremely varied in lithology 

and thickness and reflects sedimentation in a very shallow 

environment. It differs from the overlying units in its coarse 

grain size and lateral variability. Principal lithologies are 

pebble conglomerate and sandstone. Individual clasts in 

these detrital beds are composed of chert, shale, quartzite, 

quartz, and phosphorite. With the exception of phosphorite, 

these are the constituents of the Silurian and Ordovician 

strata in the underlying rocks. Detrital beds commonly 

show effects of strong currents such as abundance of scours 

and crossbedding. Beds of bioclastic limestone are fairly 

common in the sequence. These are generally quartz-silty, 

quartz-sandy, and phosphatic, and locally they are partially 

replaced by secondary silica. They contain abundant 

brachiopods, mollusks, bryozoa, and scarce specimens of 

the mollusk Atomodesma (fig. 11), the latter as determined 

by Bruce Runnegar (written commun. (1969). Some beds 

contain abundant length-slow chalcedony blebs and nodules 

that suggest the former presence of evaporite minerals. The 

brachiopod fauna indicates the lowest member is of midPermian age. The lowest member ranges from 0 to at least 

100 m thick.

Figure 9. Mount Ichabod, phosphatic sandstone. Dark clast is 

a phosphatic steinkern; the brown clast is phosphate containing 

spicules; the circular clast is a crinoid columnal; other clasts are 

mainly chert (gray) and quartz (white).

Figure 10. Dorsey Canyon, sandstone from unit 2. The clasts 

consist of quartz, chert, shale, and (sparse) phosphate. An angular 

quartzite clast occupies most of the right-hand side of the picture. 

The large ovoid grain on the left side is shale. Smaller grains are 

mostly quartz (white) and chert (gray).

to top, of (1) conglomerate composed of large clasts identical 

in composition to quartzite and chert of the underlying 

Ordovician and Silurian units, (2) sandstone and siltstone 

composed mainly of quartz and chert grains (fig. 10), and 

(3) a unit of mainly interbedded sandstone and chert. The 

depositional contacts at the base of each of the three units are 

well exposed (Ketner and others, 1993). 

The depositional contact between units 2 and 3 is 

important because it solves a longstanding structural problem. 

Coats and Gordon (1972) discussed two Permian stratigraphic 

units in the area that they believed were structurally 

juxtaposed: a siltstone and sandstone unit termed the Edna 

Mountain Formation, and a chert-bearing unit termed the 

Phosphoria Formation (the type Edna Mountain Formation is 

150 km to the southwest). Actually, these two units constitute 

the upper two stratigraphic units at Dorsey Canyon, and they 

are in stratigraphic continuity.

 Coats and Gordon (1972) tabulated 14 fossil collections 

from the Dorsey Canyon–Divide Peak area, a very informative 

contribution to the nature and age span of the Phosphoria 

Sea in northern Nevada. All 14 of the collections contain 

the brachiopod Spiriferella assemblage characteristic of the 

type Edna Mountain Formation. Four of the collections, in 

addition to the Spiriferella assemblage, contain the brachiopod 

Cyrtorostra assemblage characteristic of the Phosphoria 

Formation. As interpreted in the present report, the 10 

collections containing only the Edna Mountain assemblage 

are from unit 2 described previously. The four collections with 

both the Spiriferella and Cyrtorostra assemblages are from the 

stratigraphically highest beds, unit 3 described previously. The 

ample paleontological data from units 2 and 3 presented by 

Coats and Gordon (1972) show beyond doubt that the Permian 
8 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

Figure 11. Northern Adobe Range, lower member, prismatic shell 

of Atomodesma in phosphatic limestone laced with length-slow 

chalcedony.

Figure 12. Northern Adobe Range, middle member, spicule chert 

showing dolomite rhombs and phosphate (dark brown) in axial 

canals of spicules.

Figure 13. Northern Adobe Range, top member, phosphatic 

pellets in siltstone matrix of dolomite rhombs, quartz, and spicules. 

Some of the pellets are obscurely concentrically laminated; some 

have quartz grain cores.

Figure 14. Northern Adobe Range, top member, phosphatic 

steinkerns in slightly phosphatic siltstone.

The middle member although relatively thin and inconspicuous can be traced continuously for several kilometers. 

This member is composed of brown, richly phosphatic, 

pelletal, crossbedded quartz siltstone or mudstone and chert 

(fig. 12). It contains sparse shells of Atomodesma. The middle 

member is about 20 m thick.

The upper member consists almost entirely of darkbrown phosphatic quartz siltstone (fig. 13), mudstone, and 

shale. Less common constituents are lenses of sandstone and 

small-pebble conglomerate composed of chert clasts and 

phosphate rock clasts, crossbedded phosphatic siltstone with 

small phosphatic steinkerns (fig. 14) resembling that of the 

middle unit, and thin phosphorite beds. The upper member is 

at least 180 m thick.

The upper and lower members were dated by collections 

of brachiopods and pelecypods as mid-Permian by B.R. 

Wardlaw and Mackenzie Gordon (Ketner and Ross,1990).

An isolated map unit, not subdivided into members, 

consists of sandstone, conglomerate, limestone, dolomite, 

phosphatic siltstone, phosphatic mudstone, and phosphatic 

spicule chert. This unit, probably equivalent to the three units 

described previously, was dated by a fossil collection of which 

Mackenzie Gordon wrote: “This collection, from a limestone 

bed, is... equivalent to part of the Park City Formation.” The 
Shallow Marine Deposits of the Phosphoria Sea in Nevada 9

Park City is a carbonate facies of the Phosphoria Formation 

(McKelvey and others, 1959).

Although the percentage of phosphate is low on average (table 1), the substantial thickness of the mid-Permian 

sequence indicates a large amount of phosphate.

The principal forms of phosphate in the northern Adobe 

Range are as follows:

1. Round or ovoid pellets of pure phosphate between 0.05 

and 0.5 mm in diameter. Some of these are built up 

around nuclei of detrital quartz grains or carbonate grains.

2. Small irregularly shaped grains. These are common in 

siltstone where they conform to the spaces available 

among detrital quartz grains.

3. Large irregular nodules composed of homogeneous 

phosphate or aggregates of phosphatic pellets and other 

sedimentary debris. These grains, which can be at least 

4 cm in the longest dimension, seem to be fragments of 

preexisting beds of phosphorite that have been broken up 

and moved short distances.

4. Internal casts of small pelecypods about 0.5 to 1 cm in 

length.

5. Rodlike fillings of the axial canals of spicules. These 

range from 0.2 mm to 0.3 mm in diameter, and although 

they can be a few millimeters long they are usually 

broken into short segments. 

Table 1. Percent P2O5 of samples chosen at arbitrary equal intervals across mid-Permian 

stratigraphic units, northern and southern Adobe Range.1

Northern Adobe 

Range (loc. 12)

Lower member

±100 m thick

±7-meter intervals

Northern Adobe 

Range (loc. 12)

Middle member

±20 m thick

±7-meter intervals

Northern Adobe 

Range (loc. 12)

Upper member

±180 m thick

±8-meter intervals

Southern Adobe 

Range (loc. 14)

Upper half

±300 m thick

±10-meter intervals

0.66 (top) 1.34 (top) 1.33 (top2

) 12.9 (top3)

0.50 1.64 3.52 10.1

0.24 1.45 (base) 1.54 1.88

3.57 1.5 (average) 4.14 9.31

2.82 1.54 1.23

1.66 1.36 1.60

1.30 1.05 0.94

1.76 2.89 0.69

2.02 3.10 0.62

2.97 0.56 1.54

4.26 1.54 0.34

1.66 2.38 0.63 

1.02 1.59 0.18

3.20 1.66 0.41

0.94 1.66 0.35

2.35 (base2

) 1.48 0.43

1.9 (average) 1.13 0.54

1.62 3.88

1.08 1.08

1.01 2.82

0.66 2.35

1.35 2.07

0.35 1.84

0.58 (base) 1.00

1.6 (average) 2.18

7.57

0.52

0.99

1.02

0.89

0.83

1.10 (base)

2.3 (average)

1

 Analyst: G.D. Shipley, U.S. Geological Survey.

2 The top and base of the Permian sequence in the northern Adobe Range are faulted.

3

The stratigraphic top of the Permian sequence in the southern Adobe Range is concealed.
10 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

6. Concentrically laminated phosphate oolites or the nuclear 

portion of carbonate oolites.

7. Colloform cavity fillings. These may be secondary 

deposits formed after consolidation of the sediments.

13. Peko Hills

An intact sequence of upper Paleozoic rocks in the Peko 

Hills has been divided into basal, middle, and upper units 

(Ketner and Evans, 1988). The basal unit is composed mainly 

of dolomite. Lower beds of this unit consist of quartzitepebble and chert-pebble conglomerate, cherty dolomite, 

and limestone. Most of the upper beds of the basal unit are 

variably phosphatic, and dolomite beds contain length-slow 

chalcedonic blebs that probably represent original evaporite 

nodules. The maximum exposed thickness of the basal unit 

is about 610 m. The unit contains an Upper Pennsylvanian 

(Virgilian) fusulinid fauna and a Lower Permian conodont 

fauna. The basal unit therefore correlates with the Upper 

Pennsylvanian and Lower Permian Strathearn Formation of 

the Carlin Canyon area, 65 km to the southwest, in its age 

range and to some extent in its lithic composition (Smith and 

Ketner, 1975). However, the Strathearn is mostly limestone 

rather than dolomite. 

The middle unit is extremely heterogeneous. It consists 

of crossbedded, phosphatic quartz siltstone (figs. 15, 16, 17), 

phosphorite, chert-grain and quartz-grain sandstone, chertpebble conglomerate, quartz-sandy and chert-pebbly dolomite, 

and chert beds composed of spicules with phosphate-filled 

axial canals. Chemical analyses of phosphorite samples 

indicate P2

O5 levels of as much as 30 percent. The middle unit 

contains abundant evidence of shallow water origin such as 

crossbedding in coarse-grained sandstone, scoured surfaces, 

and gypsum (fig. 18). Phosphatic red beds with chalcedonic 

blebs are present in one exposure. The middle unit, which 

is about 245 m thick, contains an abundant fauna of silicified brachiopods and Lower Permian conodonts. Based on 

lithic composition and stratigraphic position, the middle unit 

is considered equivalent to the Plympton and Phosphoria 

Formations. 

The upper unit is identified as the Gerster Formation. At 

this location it is composed mostly of thick-bedded limestone 

with sporadic chert nodules and lenses. In some exposures, 

upper beds are composed of thick-bedded dolomite containing 

blebs of length-slow chalcedony, disseminated grains and 

distinct beds of quartz sand, chert sand, chert conglomerate, 

Figure 15. Peko Hills, middle unit, central pellet composed 

largely of spicules with interstitial phosphate. Darker pellets in 

this view have higher concentrations of phosphate; lighter pellets 

have higher concentrations of spicules. The pellets are in a matrix 

of dolomitic, spiculitic, phosphatic silt.

Figure 16. Peko Hills, middle unit, small pellets and ooides in 

matrix of broken spicules and fragments of phosphatic shells.

Figure 17. Peko Hills, middle unit, steinkern with phosphate and 

spicules in a matrix of silt-size quartz, spicules, and phosphate.
Shallow Marine Deposits of the Phosphoria Sea in Nevada 11

and spicule chert. This unit, which is about 200 m thick, 

contains an abundant fauna of productid brachiopods and 

large silicified pelecypods. The Gerster, in its type section in 

western Utah, is correlative with the Park City and Phosphoria 

Formations (Nolan, 1935) and is presumed to be of that age in 

the Peko Hills. Altogether, the lithic features of all three units 

indicate very shallow-water conditions.

14. Southern Adobe Range 

The exposed Permian sequence of the southern Adobe 

Range consists of the upper, Permian part of the Strathearn 

Formation, and a thick, unnamed unit (Ketner, 1973; Smith 

and Ketner, 1975). The topmost Permian beds and Triassic 

beds are not exposed in the southern part of the range as they 

are in the northern part described previously. The unnamed 

unit consists mostly of siltstone, sandstone, limestone, dolomite, and chert. The approximate upper half of the Permian 

sequence is somewhat phosphatic, and the uppermost beds 

include phosphatic chert and phosphatic, siltstone (table 1; 

fig. 19). Of six samples with hand-lens-visible phosphate not 

shown in table 1, two were below 1 percent and four ranged 

from 2 to 8 percent P2

O5. The measured section is about 600 m 

thick, but the topmost beds, commonly the most phosphatic, 

are covered and of unknown thickness.

15. Southern Piñon Range 

Permian rocks in the southern Pinon Range consist 

of limestone, sandy and silty limestone, limy siltstone, 

and conglomerate (Smith and Ketner, 1975). They overlie 

Mississippian conglomeratic rocks disconformably, and the 

Figure 18. Peko Hills, middle unit, bed of mainly gypsum (gray) 

and length-slow chalcedony (light brown) among clasts of 

phosphatic chert and siltstone.

top is erosional. The extensive fauna clearly indicates a late 

Permian age (Mackenzie Gordon, Jr., in Smith and Ketner, 

1975) and a shallow-water environment. Among the forms 

found at this locality are numerous genera of brachiopods, 

bryozoans, and crinoids. 

16. Edna Mountain 

This area was described by Ferguson and others (1952), 

and Erickson and Marsh (1974). It is the westernmost exposure of the relatively shallow-water sediments of the Phosphoria Sea at the latitude of the core area of the Phosphoria 

Formation. Permian rocks of Edna Mountain include the upper 

part of the Antler Peak Limestone and the unconformably 

overlying Edna Mountain Formation. Phosphatic strata that 

would normally be present between these two units have been 

incorporated into the Edna Mountain Formation in the form 

of sandstone and conglomerate composed, in part, of phosphatic clasts. The Antler Peak Limestone is chiefly bioclastic 

limestone and is stratigraphically equivalent to the Strathearn 

Formation and the Kaibab Limestone of more easterly parts of 

Nevada. The overlying Edna Mountain Formation as described 

by Erickson and Marsh is composed of “Chiefly brown, 

blocky-weathering, fine- to medium-grained, dark-gray, 

calcareous quartzite; locally conglomeratic. Black chert grains 

and black coprolites of fluorapatite composition are common. 

Brachiopod faunas of Late Permian age (Mackenzie Gordon, 

Jr., written commun., 1970) are locally abundant, particularly in upper part.” The mid-Permian age of the unit and the 

incorporation within it of phosphatic and spiculitic clasts, and 

the Permian age of some of the underlying rocks indicate the 

unconformity is of mid-Permian age.

Figure 19. Southern Adobe Range, irregular phosphate pellets 

and a steinkern in a matrix of angular quartz clasts, spicules, and 

minute phosphate pellets. The steinkern, on the right, contains 

numerous spicules and quartz grains.
12 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

Microscopic examination for the present report indicates 

the formation is composed largely if not mostly of angular 

radiolarian chert grains or chert grains without either spicules 

or radiolarians. Minor clastic components include dolomite 

rhombs, spiculitic chert, irregular, apparently abraded, 

phosphorite clasts (fig. 20), and in some beds, abundant 

angular clasts of length-slow chalcedony (fig. 21).

The lithic composition of the Edna Mountain in general 

matches that in parts of the mid-Permian sequences of northcentral Nevada, as was stressed by Coats and Gordon (1972). 

The angularity and poor sorting of clasts, the presence 

of spiculitic chert clasts, and the presence of phosphate 

pellets suggest derivation from nearby primary shallow-water 

sedimentary rocks typical of the Phosphoria Sea. 

The age of the Edna Mountain and its content of 

phosphatic, spicule, and chalcedonic clasts testify to uplift, 

erosion, and a return to deposition in the time interval of the 

Phosphoria Formation. The area was therefore, briefly, an 

ephemeral island in the Phosphoria Sea. 

17. Monitor Range

At Danville Canyon in the central Monitor Range, a thick 

sequence of chert, siltstone, sandstone and limestone includes 

phosphatic beds (Rogers and others, 1970). The sequence was 

dated as Permian by its stratigraphic position, its resemblance 

to known mid-Permian strata of the Phosphoria Sea, and the 

presence of the conodont Gondolella in phosphatic beds.

18. Southern Toiyabe Range

The mid-Permian Diablo Formation of the southern 

Toiyabe Range was described by Speed and others (1977) 

as “... dominantly fine-to coarse-grained calcarenite and 

pebbly calcarenite; interbeds of limy quartz-chert sandstone 

and microbreccia and skeletal hash....” A predominantly 

brachiopod fauna indicates a mid-Permian age approximately 

equivalent with the Phosphoria Formation and lower Gerster 

Limestone according to Ferguson and Cathcart (1954) and 

written communications to Speed by Mackenzie Gordon, Jr. 

(1967), and Bruce R. Wardlaw (1977).

19. Southern Toquima Range

The Diablo Formation in the southern Toquima Range at 

Willow Springs is described as “... limy siltstone and finegrained sandstone, subordinate brown and gray silty and sandy 

limestone, and sparse conglomeratic layers at the base.” (Poole 

and Wardlaw, 1978). Marine fossils indicate a mid-Permian 

(late Leonardian) age. 

20. Candelaria Hills

The middle Permian Diablo Formation in the type area 

as redefined by Speed and others (1977) is a thin (<25 m), 

slightly metamorphosed unit composed of conglomerate, 

sandstone, siltstone, silty chert, and dolomite. The Diablo is 

underlain by the Palmetto Formation of Ordovician age and 

is overlain by Triassic rocks. As in correlative sandy strata in 

northern Nevada, clasts of the Diablo are mainly chert and 

quartz. Phosphate, which is somewhat recrystallized, occurs 

as irregular masses of pelletal phosphorite (fig. 22) and as 

isolated pellets and steinkerns in sandstone (fig. 23). An 

Figure 20. Edna Mountain, Edna Mountain Formation, two 

large clasts of phosphate in a matrix of quartz, spiculitic 

chert, and small phosphate clasts. The large phosphate clasts 

differ from most Permian pellets in having irregular or ragged 

surfaces apparently from their history of erosion from the 

primary phosphatic sediment and redeposition as sandstone 

and conglomerate. The primary sediment evidently was, in part, 

spiculitic chert, phosphate, and length-slow chalcedony.

Figure 21. Edna Mountain Formation, length-slow chalcedony 

clasts (light-colored bars) in sandstone, here composed mainly of 

angular chert grains.
Shallow Marine Deposits of the Phosphoria Sea in Nevada 13

unusually conspicuous phosphate bloom coats some of the 

weathered surfaces.

As noted by Speed and others (1977) a shallow 

depositional environment is indicated by onlap of the Diablo 

onto the source beds of clasts composing the Diablo. The 

shelly, mainly brachiopod, fauna is similar to that of the 

Phosphoria Formation (Ferguson and others, 1954).

Southern Nevada 

Permian strata in extreme southern Nevada consist of a 

thick sequence of limestone, red beds, and cherty, gypsiferous 

limestone of Early Permian age, overlain by the Kaibab 

Limestone (Tschantz and Pampeyan, 1970). The Kaibab 

in southern Nevada is composed mainly of limestone with 

chert nodules and lenses, and minor dolomite (Tschantz and 

Pompeyan, 1970; Longwell and others, 1965). Phosphate 

pellets are very sparsely present in some exposures. Similar 

deposits are present at the base of phosphatic deposits in 

northern Nevada and some of them have been termed Kaibab; 

but if richly phosphatic beds had ever been present above 

the Kaibab in southern Nevada they were eliminated by Late 

Permian or Early Triassic erosion. The existence of such 

an erosional interval in middle to southern Nevada where 

phosphatic sediments appear to be missing has been observed 

at many localities ( Longwell and others, 1965; Tschanz and 

Pampeyan, 1970; Hose and Blake, 1976).

Conodonts extracted from each of the Kaibab localities of 

southern Nevada shown in figure 1, and others in the vicinity, are of mid-Permian age according to A.G. Harris (Harris, 

unpub. data; Harris and others, 2005; Harris and Crafford, 

2007), which makes the formation approximately correlative 

with the phosphatic rocks of northern Nevada. 

The Kaibab has been reported just over the southern 

Nevada border in southeastern California (Hewett, 1956), 

but the significance of Phosphoria-age strata in other parts of 

California (for example, Merriam and Hall, 1957) is uncertain 

owing to recent radical revisions in stratigraphy and tectonics 

(for example, Stone and Stevens, 1988; Stevens and others, 

2005).

Figure 22. Candelaria Hills, Diablo Formation, phosphorite 

mass composed of phosphate pellets in a matrix of quartzsilty phosphorite. Some pellets ar nucleated; some show faint 

concentric structure.

Figure 23. Candelaria Hills, Diablo Formation. A large phosphatic 

steinkern, on the right, is in a matrix of phosphate pellets and 

silt-size chert and quartz clasts. The tip of the steinkern has 

been drawn out toward the left and its outlines blurred by the 

metamorphic process.
14 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

The Allochthonous Havallah Sequence

The Havallah sequence is a relatively deep water deposit 

of Late Devonian to mid-Permian age exposed widely in 

more westerly parts of Nevada. The sequence is sliced by 

low-angle faults and is almost universally considered to be 

entirely allochthonous. In the interval between 1972 and 1992, 

a large number of published reports established the concept 

that the Havallah had been thrust to its present location from 

a distant oceanic or back-arc basin. However, evidence cited 

by Murchey (1990) and Ketner (2008) suggest a more local 

site of deposition. Ketner (2008) presented evidence that the 

Havallah was deposited, not directly on oceanic crust, but on 

a thick sequence of Cambrian to Silurian terrigenous strata of 

the miogeocline. Lithic and paleontological data from the following three localities indicate that the uppermost part of the 

Havallah is of mid-Permian age and closely related to strata of 

the Phosphoria Sea.

21. Battle Mountain 

The Pumpernickel Formation of Roberts (1964), a 

subunit of the Havallah sequence, is a relatively deep water 

deposit. According to Roberts, it consists largely of chert and 

argillite but includes some limestone, sandstone, conglomerate 

and intercalated greenstone. 

Roberts’ pioneer work was supplemented by a very 

informative study by B.L. Murchey (1990) of the lithic 

composition and fauna of the entire Havallah sequence 

including the “Pumpernickel” at Battle Mountain. Although 

Roberts tentatively assigned the “Pumpernickel” at this 

location to the Pennsylvanian, Murchey’s data clearly indicate 

the unit contains a mid-Permian fauna and the mid-Permian 

part is genetically related to the Phosphoria Formation. The 

Phosphoria connection was expressed by Murchey as follows, 

p. 145 and 147: “The faunas in the sponge turbidites are 

indistinguishable from faunas in the lower Guadalupian Rex 

chert member of the Phosphoria Formation....” and “Sponge 

spicule turbidites of Leonardian or Guadalupian age were 

redeposited into the ... slope setting from a shelf environment 

similar to, and possibly coeval with, that in which the Rex 

Chert Member of the Phosphoria Formation was deposited.”

Not only is the fauna of part of the “Pumpernickel” 

similar to that of the Phosphoria, some aspects of the lithic 

composition also are similar. Axial canals of spicules in the 

spicule chert turbidites of the “Pumpernickel” are commonly 

filled with phosphate as they are in the Phosphoria Formation, 

and phosphate pellets typical of the Phosphoria are present in 

some (figs. 24, 25).

Phosphate is moderately concentrated in some beds of 

the mid-Permian parts of the Havallah. Chemical analyses of 

five samples of spicule chert with hand-lens-visible phosphate 

indicate P2

O5 contents ranging from 2.7 to 4.0 percent, and of 

a sample of phosphatic sandstone, 5.4 percent P2O5 (fig. 26). 

The thickness of the mid-Permian part of the sequence at 

Battle Mountain is uncertain owing to faults and folds.

Figure 24. Battle Mountain, mid-Permian part of Havallah 

sequence, “Pumpernickel” of Roberts (1964). Small phosphate 

rods and pellets are in chert-cemented quartz silstone. The rods 

are likely fillings of axial canals of spicules, although that is not 

apparent in this specimen owing to recrystallization of silica.

Figure 25. Battle Mountain, mid-Permian part of Havallah 

sequence, “Pumpernickel” of Roberts (1964). Phosphate pellets 

are in a matrix mainly of spicules and silt-size quartz and chert 

grains. Minor components are shell fragments, schist, and 

feldspar.

22. Southern Shoshone Range

In the southern Shoshone Range, the upper part of the 

allochthonous Havallah sequence includes sandy limestone, 

bedded chert, spicule chert, and phosphatic sandstone 

(Tomlinson, 1990). Benita Murchey examined sponge spicules 

from this area (termed Reese River area by Tomlinson) and 

concluded that they were identical to those in the upper 

Havallah of Battle Mountain. The mid-Permian age was 

determined by means of radiolarians and conodonts.
Shallow Marine Deposits of the Phosphoria Sea in Nevada 15

Tomlinson describes the phosphatic grains in the 

phosphatic sandstones as follows: “Collophane pellets, 

intraclasts, ooliths, and bioclasts. Bioclasts include conodonts, 

vertebrate debris, and small phosphoratized gastropods, 

bivalves, and ostracods.” This assemblage suggests derivation 

of clasts from the more shallow Phosphoria Sea.

23. Northern Toiyabe Range

In the northern Toiyabe Range, the upper part of the 

allochthonous Havallah sequence includes unmeasured 

thicknesses of mudstone, argillite, phosphatic sandstone, and 

radiolarian chert (Tomlinson, 1990). Sedimentary structures 

indicate these strata, like correlative strata at Battle Mountain, 

are turbidites. In the Toiyabe Range, the cherts are radiolarian 

rather than spiculitic, indicating a relatively deep-water 

depositional environment (Murchey, 1990). A mid-Permian 

age was determined by means of the radiolarians.

Tomlinson describes the phosphate clasts in the 

phosphatic sandstones as follows: “Collophane pellets, 

intraclasts, and ooliths....” These commonly have inclusions of 

sponge spicules. The description suggests derivation of clasts 

from the Phosphoria Sea.

Western Correlatives of the Havallah Sequence

The Mississippian to Permian rocks of the Hot Springs 

Range (fig. 1, no. 24) and the East Range (fig. 1, no. 25) are 

correlative with the Havallah sequence and are considered 

to have been deposited in the same marginal sea on the same 

Cambrian to Silurian strata of the miogeocline (Ketner, 2008). 

24. Northern Hot Springs Range

Rocks correlative with those of the Phosphoria Sea 

are present in the northern Hot Springs Range, but they 

are of different lithic composition and represent a different 

environment of deposition from those of the Phosphoria Sea. 

Two of the tectonostratigraphic units mapped by A.E. 

Jones (1997) are correlative with the Phosphoria. Jones 

described one of the two units, the Golconda mélange, as 

follows. “Although the melange is a disrupted, heterogeneous 

unit, it does have mappable lithologic horizons. Large blocks 

in the sheared basaltic tuff and argillite matrix include pillow 

basalt, red ribbon chert, interbedded chert and sandstone, 

calcareous siltstone, and massive limestone and volcanic 

breccia.” No phosphatic beds or spicule chert were mentioned 

by Jones.

Concerning the age of the Golconda mélange, Jones 

stated that “Black chert beds in an olive basaltic matrix at 

the southern boundary of the melange contain middle to late 

Leonardian conodonts....” Because conodonts can, and frequently are, reworked, the data indicate a middle Leonardian 

or younger age. 

Another tectonostratigraphic unit, termed the Poverty 

Peak mélange, is described as follows. The Poverty Peak 

mélange “...has a fabric similar to the Golconda melange but 

its block composition is somewhat different. It is composed 

of large blocks of altered serpentine gabbro, basalt breccia, 

and red radiolarian chert in a tuffaceous basalt matrix.” No 

phosphatic beds or spicule cherts were mentioned by Jones. 

Regarding the age of the Poverty Peak mélange, Jones 

stated that “All of the radiolarian ages from chert blocks in 

the Poverty Peak mélange are Early Permian.” Because the 

radiolarians are from blocks (clasts), the age of the mélange 

must be Early Permian or younger. It is highly unlikely that 

either the Golconda or Poverty Peak could be of Triassic age 

because the Triassic sequence in the region is well studied and 

includes no such strata. If the two mélanges are essentially 

the same stratigraphic unit as interpreted by Ketner (2008), 

the age of the combined unit must fall within the middle 

Early Permian to Late Permian interval and be, at least in 

part, contemporaneous with the Phosphoria Formation. The 

mid-Permian rocks in the Hot Springs Range were deposited 

in the same sea as was the Havallah sequence and constitute a 

western facies of the Havallah (Ketner, 2008).

Figure 26. Battle Mountain, mid-Permian part of Havallah 

sequence, “Pumpernickel” of Roberts (1964), phosphatic 

sandstone. Large dark clast in upper left corner and numerous 

small dark clasts are phosphate, white clasts are quartz, and 

clasts of various shades of gray are mostly quartz and chert. 

Schist, siltstone, and feldspar are minor components. This 

specimen contains 5.4 percent P2

O5. It resembles the Edna 

Mountain Formation in its variety and angularity of chert and 

quartz clasts and in the ragged outlines of the phosphate clasts.
16 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

25. Northern East Range 

A principal formation of the East Range is the Inskip 

Formation, a heterogeneous Upper Devonian to Permian 

sequence (Whitebread, 1994; Ketner and others, 2000, 2005; 

Ketner, 2008). The Inskip is thought to be a facies of the more 

widespread Havallah sequence of the same age range. Fossils 

are very scarce in the Inskip owing partly to dynamic metamorphism; but at Rock Hill Canyon, in the northern part of the 

Inskip exposure and close to the contact with Triassic rocks, 

conodont collections range from Mississippian to Permian 

and a fusulinid collection is of Early Permian age. Two of 

the conodont collections indicate a Wordian, Late Permian, 

age for some of the strata. The upper part of the Inskip at this 

location includes such lithic types as basalt, felsite, large-slab 

conglomerate, arkosic sandstone, bedded chert, and limestone. 

Neither spicule chert nor phosphatic beds were identified but a 

thorough search was not made.

Like the mid-Permian strata of the Hot Springs Range, 

those of the East Range are thought to have been deposited 

in the same sea as the Havallah sequence and to constitute a 

facies of the Havallah (Ketner, 2008).

Correlatives of the Phosphoria Formation in 

Terranes Thought to be Accretionary 

The Permian rocks at Quinn River Crossing, and the Pine 

Forest Range are isolated exposures in an area where Permian 

rocks are widely regarded as having been accreted from an 

unknown original location (Crafford, 2008; Silberling, 1991; 

Silberling and others, 1987, 1992). Without much more data 

their relation to the Phosphoria Sea remains enigmatic.

26. Quinn River Crossing

The Quinn River Crossing area includes an exposure 

of quartzite composed mainly of quartz grains and angular 

chert grains but that also contains sporadic clasts of phosphate 

(Ketner and Wardlaw, 1981). The unit, which appears to be in 

fault contact with other Paleozoic rocks, resembles the Edna 

Mountain Formation in the variety of clasts, in their angularity, 

and in the presence of phosphate. However, according to Jones 

(1990) the abundant Permian fauna of another structural block, 

the Black Rock terrane, is closely related to correlatives in 

northern California. A linkage between the Quinn River rocks 

with the Phosphoria Sea therefore is problematical.

27. Pine Forest Range 

Permian rocks in the Pine Forest Range include a unit 

composed of three members (Wyld, 1990). Wyld describes 

these as follows: “The lower member consists of gray limestone with thin interbeds of calcareous shale, and often 

contains unbroken rugose and/or tabulate corals. Gradationally overlying this member is a clastic member that consists of 

sandstone, conglomerate, shale, and minor limestone. Sandstone and conglomerate contain abundant sedimentary and 

volcanic clasts, less common feldspar, minor quartz, and rare 

plutonic clasts. Interbedded limestones are thin and sometimes 

contain up to 90 percent fossils, including abundant crinoid 

stems. The upper member is a limestone that consists of up to 

90 percent unbroken fossils (mostly brachiopods) in a muddy 

carbonate matrix.” Brachiopods in the upper member are of 

Guadalupian age according to B.R. Wardlaw as quoted by 

Wyld. This sequence seems to resemble the Kaibab-PlymptonGerster triplet of more easterly parts of Nevada. However, 

Wyld sees faunal links with northern California. As at Quinn 

River Crossing, the data appear to be ambiguous and a close 

linkage with the Phosphoria Sea cannot be justified at present.

Conclusions

The Phosphoria Sea and Its Sediments in 

Nevada

The mid-Permian Phosphoria Sea extended continuously 

more than 500 km westward and more than 700 km 

southwestward from the core area in southeastern Idaho (the 

net result of Mesozoic contraction and Tertiary extension is 

considered to be zero). The Phosphoria Sea therefore extended 

across formerly postulated emergent areas such as those 

depicted in publications as “Humboldt highland belt” (Ketner, 

1977), “Antler orogenic belt” (Snyder and others, 1991), 

and “emergent Antler highland” (Piper and Link, 2002). 

Throughout its extent in Nevada the Phosphoria Sea was 

shallow, deepening only at its western extremity in western 

Nevada.

Typical strata of the Phosphoria Sea in Nevada are 

conglomerate, quartz- and chert-sandstone, siltstone, 

limestone, dolomite, gypsiferous beds, spicule chert 

and phosphorite. Testifying to shallow conditions are 

conglomerate, crossbedding in sandstone, scours, ooids, 

dolomite, and gypsum. Across its entire extent, it had a fauna 

similar to that of the type Phosphoria Formation. Phosphate 

particles, such as pellets, nucleated pellets, concentrically 

laminated pellets, compound pellets, and phosphatic 

fossil fragments, are generally similar to those of the type 

Phosphoria based on this study and on comparison with the 

descriptions and illustrations of Cook (1969), Lowell (1952), 

Mabie and Hess (1964), and Trappe (2001).

Steinkerns appear to be more abundant in the Nevada 

deposits than in the Phosphoria of the type area; fish scales, 

and phosphatic bioclasts less common. In general, quartz and 

chert clasts in Nevada are relatively large compared with those 

in the type area of the Phosphoria, and organic-rich mudstone 

is less common.
References Cited 17

Pennsylvanian and Permian Strata Underlying 

Sediments of the Phosphoria Sea in Nevada 

Commonly the mid-Permian rocks of northern Nevada 

are underlain conformably by a thick sequence of Middle 

Pennsylvanian to Early Permian age as indicated in several 

of the foregoing descriptions. The strata, composed of silty, 

sandy, commonly gypsiferous rocks, and impure limestone, 

are hundreds of meters thick in many places, and they lie disconformably or unconformably on rocks ranging from lower 

Paleozoic to Pennsylvanian in age. Although they are designated by many local stratigraphic names, they are essentially 

equivalent to, and probably genetically related to, the Oquirrh 

Formation of Utah and Wood River Formation of Idaho as 

proposed by Geslin (1998).

The Phosphate Content of Phosphoria-age 

Sediments in Nevada

Phosphate deposition was a characteristic of the 

Phosphoria Sea throughout its wide extent in Nevada, but 

the phosphate was much diluted by clastics and carbonate. 

From the small amount of quantitative data available based 

on sampling in the Adobe Range, it seems likely that the 

amount of apatite in mid-Permian sequences in some parts 

of Nevada may not differ greatly from that in the core area 

of southeastern Idaho. However, an exact comparison is not 

possible because of uncertainty as to the precise stratigraphic 

equivalence between the two areas and differences in methods 

of sampling.

The Western Margin of the Phosphoria Sea

The Phosphoria Sea merged westward into a body of 

relatively deep water in which the mid-Permian part of the 

Havallah sequence was deposited. The Havallah, an Upper 

Devonian to Permian sequence, is sliced by thrust faults and is 

commonly considered allochthonous wherever it is exposed. 

Arguably, the Havallah has not moved far from its point of 

origin (Ketner, 2008). This opinion, based on stratigraphic 

evidence, is supported by paleontological and lithic evidence 

cited by Murchey (1990) and quoted elsewhere in this report, 

linking the mid-Permian part of the Havallah sequence at 

Battle Mountain to the Phosphoria Formation. In any event, 

the distance traveled by the allochthonous Havallah is a matter 

of opinion, and the exact location of the transition between the 

Phosphoria Sea and deeper Havallah Sea therefore remains 

uncertain.

 In the Late Devonian and Mississippian, the sea in 

which the lower part of the Havallah was deposited was of 

restricted width, bounded on the west by a landmass (Ketner 

and others, 2005); but whether that condition persisted through 

the Permian is unknown. The presence of fusulinid-bearing 

limestone of Permian age at its westernmost exposure, the East 

Range, suggests the sea at that point was not very deep. Many 

geologists believe Paleozoic terranes to the west of the Hot 

Springs and East Ranges (24 and 25 on fig. 1) were accreted 

from unknown locations (Silberling, 1991; Silberling and 

others, 1987, 1992). In the absence of concrete evidence, the 

question of what lay west of the Hot Springs and East Ranges 

in mid-Permian time remains unanswered.

Phosphoria Formation and the Oceanic 

Upwelling Model

Modern phosphorites form along the western margins 

of continents where nutrient-rich oceanic waters well up 

against the continental margin. Many believe that ancient giant 

deposits such as the Phosphoria Formation were deposited in 

the same situation as indicated by Glenn and others (1994) 

and quoted in the introduction to this report. However, a close 

genetic relation between oceanic upwelling at the continental 

margin and the Phosphoria Formation in its core area of 

greatest phosphate concentration is hard to justify because 

of the great expanse of shallow water that lay to the west of 

the core area. The area in and near southeastern Idaho where 

the concentration of phosphate is greatest apparently was a 

euxinic, starved basin deep within a very extensive, shallow 

sea.

Acknowledgments

 Reviews by Robert J. Hite and Russell G. Tysdal 

improved the message and expression of the manuscript and 

are greatly appreciated.

References Cited

Bezzerides, T.L., 1967, Triassic stratigraphy and geology 

of the O’Neil Pass area, Elko County, Nevada: Eugene, 

University of Oregon, Master’s thesis, 74 p.

Coats, R.R., 1986, Invertebrate and paleobotanical fossils 

collected in Elko County, Nevada: Nevada Bureau of Mines 

and Geology Open-File Report 86–1, 397 p.

Coats, R.R., 1987, Geology of Elko County, Nevada: Nevada 

Bureau of Mines and Geology Bulletin 101, 111 p. 

Coats, R.R., and Gordon, Mackenzie, Jr., 1972, Tectonic 

implications of the presence of the Edna Mountain Formation in northern Elko County, Nevada: U.S. Geological 

Survey Professional Paper 800–C, p. C85–C94.

Collinson, J.W., 1968, Permian and Triassic biostratigraphy 

of the Medicine Range, northeastern Nevada: Wyoming 

Geological Association, Earth Science Bulletin, v. 1, no. 4, 

p. 25–44.
18 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

Cook, P.J., 1969, The petrology and geochemistry of the 

Meade Peak Member of the Phosphoria Formation: Boulder, 

University of Colorado, Ph.D. dissertation, 204 p.

Crafford, A.E.J., 2008, Paleozoic tectonic domains of 

Nevada—An interpretive discussion to accompany the 

geologic map of Nevada: Geological Society of America 

Geosphere, v. 4, no. 1, p. 260–291.

Erickson, R.L., and Marsh, S.P., 1974, Geologic map of the 

Golconda quadrangle, Humboldt County, Nevada: U.S. 

Geological Survey Geologic Quadrangle Map GQ–1174, 

scale 1:24,000.

Ferguson, H.G., and Cathcart, S.H., 1954, Geology of the 

Round Mountain quadrangle, Nevada: U.S. Geological 

Survey Geological Quadrangle Map GQ–40, scale 

1:125,000.

 Ferguson, H.G., Muller, S.W., and Cathcart, S.H., 1954, Geologic map of the Mina quadrangle, Nevada: U.S. Geological 

Survey Geologic Quadrangle Map, GQ–45, scale 1:250,000.

Ferguson, H.G., Muller, S.W., and Roberts, R.J., 1951, 

Geologic map of the Winnemucca quadrangle, Nevada: U.S. 

Geological Survey Geologic Quadrangle Map GQ–11, scale 

125,000.

Ferguson, H.G., Roberts, R.J., and Muller, S.W., 1952, 

Geologic map of the Golconda quadrangle: U.S. Geological 

Survey Geologic Quadrangle Map GQ–15, scale 1:125,000.

Folk, R.L., and Pittman, J.S., 1971, Length-slow 

chalcedony—A new testament for vanished evaporites: 

Journal of Sedimentary Petrology, v. 41, no. 4, 

p. 1045–1058.

Fraser, G.D., Ketner, K.B., and Smith, M.C., 1986, Geologic 

map of the Spruce Mountain 4 quadrangle, Elko County, 

Nevada: U.S. Geological Survey Miscellaneous Field 

Studies Map, MF–1846, scale 1:24,000.

Gardner, D.H.,1968, Structure and stratigraphy of the northern 

part of the Snake Mountains, Elko County, Nevada: Eugene, 

University of Oregon, Ph.D. dissertation, 264 p.

Geslin, J.K., 1998, Distal ancestral Rocky Mountains 

tectonism: Evolution of the Pennsylvanian-Permian 

Oquirrh-Wood River basin, southern Idaho: Geological 

Society of America Bulletin, v. 110, no. 5, p. 644–663.

Glenn, C.R., and Arthur, M.A., 1988, Petrology and major element geochemistry of Peru margin phosphorites and associated diagenetic minerals—Authigenesis in modern organic 

rich sediments: Marine Geology v. 80, p. 231–268.

Glenn, C.R., Föllmi, K.B., Riggs, S.R., Baturin, G.N., Grimm, 

K.A., Trappe, Jörg; Abed, A.M., Galli-Olivier, Carlos, 

Garrison, R.E., Ilyin, A.V., Jehl, Caroline, Rohrlich, Vera, 

Sadaqah, R.M.Y., Schidlowski, Manfred, Sheldon, R.E., and 

Siegmund, Hendrik, 1994, Phosphorous and phosphorites—

Sedimentology and environments of formation: Eclogae 

Geologicae Helvetiae, v. 87, no. 3, p. 747–788.

Harris, Anita G., and Crafford, A.E.J., 2007, A digital 

conodont database of Nevada, in, Crafford, A.E.J., 2007, 

Geologic map of Nevada: U.S. Geological Survey Data 

Series 249, CD–ROM.

Harris, A.G., Page, W.R., Krumhardt, A.P., Repetski, J.E., 

and Turner, K.J., 2005, Conodont database and analysis of 

conodont color alteration patterns in the Las Vegas 30 ́x 

60 ́ quadrangle, Clark and Nye Counties, Nevada, and Inyo 

County, California: U.S. Geological Survey Open-File 

Report 2005–1343, http://pubs.usgs.gov/of/2005/1343/.

Hewett, D.F., 1956, Geology and mineral resources of 

the Ivanpah Quadrangle, California and Nevada: U.S. 

Geological Survey Professional Paper 275, 172 p.

Hintze, L.F., 1988, Geologic history of Utah: Brigham Young 

University Geology Studies, Special Publication 7, 202 p.

Hose, R.K., and Blake, M.C., Jr., 1976, Geology and mineral 

resources of White Pine County, Part 1, Nevada: Nevada 

Bureau of Mines and Geology Bulletin 85, 105 p.

Hose, R.K., and Repenning, C.A., 1959, Stratigraphy of the 

Pennsylvanian, Permian, and Lower Triassic rocks of the 

Confusion Range, west-central Utah: American Association 

of Petroleum Geologists Bulletin, v. 43, p. 2167–2196.

Jones, A.E., 1990, Geology and tectonic significance of terranes near Quinn River Crossing, Nevada, in Harwood, 

D.S., and Miller, M.M., eds., Paleozoic and early Mesozoic 

paleogeographic relations; Sierra Nevada, Klamath Mountains, and related terranes: Boulder, Colorado, Geological 

Society of America Special Paper 255, p. 239–253.

Jones, A.E., 1997, Geologic map of the Hot Springs Peak 

quadrangle and the southeastern part of the Little Poverty 

quadrangle, Nevada: Nevada Bureau of Mines and Geology 

Field Studies Map 14, scale 1:24,000.

Keene, J.B., 1983, Chalcedonic quartz and occurrence of 

quartine (length-slow chalcedony) in pelagic sediments: 

Sedimentology, v. 30, no. 3, p. 449–454.

Ketner, K.B., 1973, Preliminary geologic map of the Hunter 

quadrangle, Elko County, Nevada: U.S. Geological Survey 

Miscellaneous Field Studies Map MF–539, scale 1:24,000.
References Cited 19

Ketner, K.B., 1977, Late Paleozoic orogeny and 

sedimentation, southern California, Nevada, Idaho, and 

Montana, in Stewart, J.H., Stevens, C.H., and Fritsche, 

A.E., eds., Paleozoic paleogeography of the western 

United States: Society of Economic Paleontologists and 

Mineralogists, Pacific Coast Paleogeography Symposium 1, 

p. 363–369.

Ketner, K.B., 2008, The Inskip Formation, the Harmony 

Formation, and the Havallah Sequence of Northwestern 

Nevada—An interrelated Paleozoic assemblage in the 

home of the Sonoma orogeny: U.S. Geological Survey 

Professional Paper 1757, 20 p.

Ketner, K.B., Crafford, A.E.J., Harris, A.G., Repetski, J.E., 

and Wardlaw, B.R., 2005, Late Devonian to Mississippian 

arkosic rock derived from a granitic terrane in northwestern 

Nevada adds a new dimension to the Antler orogeny, in

Rhoden, H.N., Steininger, R.C., and Vikre, P.G., eds., 

Geological Society of Nevada Symposium 2005: Window 

to the World, Reno, Nevada, May 2005, p. 135–145.

Ketner, K.B., and Evans, J.G., 1988, Geologic map of the 

Peko Hills, Elko County, Nevada: U.S. Geological Survey 

Miscellaneous Investigations Series Map I–1902, scale 

1:24,000.

Ketner, K.B., Murchey, B.L., Stamm, R.G., and Wardlaw, 

B.R., 1993, Paleozoic and Mesozoic rocks of Mount Ichabod and Dorsey Canyon, Elko County, Nevada—Evidence 

for post-Early Triassic emplacement of the Roberts Mountains and Golconda allochthons: U.S. Geological Survey 

Bulletin 1988–D, p. D1–D12.

Ketner, K.B., Murchey, B.L., Stamm, R.G., and Wardlaw, 

B.R., 1996, Geologic map of the Mount Ichabod area, Elko 

County, Nevada: U.S. Geological Survey Miscellaneous 

Investigations Series Map I–2535, scale 1:24,000.

Ketner, K.B., and Ross, R.J., Jr., 1990, Geologic map of 

the northern Adobe Range, Elko County, Nevada: U.S. 

Geological Survey Miscellaneous Investigations Map 

I–2081, scale 1:24,000.

Ketner, K.B., and Wardlaw, B.R., 1981, Permian and Triassic rocks near Quinn River Crossing, Humboldt County, 

Nevada: Geology, v. 10, p. 298–303.

Ketner, K.B., Wardlaw, B.R., Harris, A.G., and Repetski, J.E., 

2000, The East Range, northwestern Nevada: A neglected 

key to the tectonic history of the region, in Cluer, J.K., 

Price, J.G., Struhsacker, E.M., Hardyman, R.F., and Morris, 

C.L., eds., Geology and ore deposits 2000: The Great Basin 

and beyond: Geological Society of Nevada Symposium 

Proceedings, May 15–18, 2000, p. 389–396.

Longwell, C.R., Pampeyan, E.H., Bowyer, Ben, and Roberts, 

R.J., Geology and mineral deposits of Clark County, 

Nevada: Nevada Bureau of Mines and Geology, Bulletin 62, 

218 p.

Lowell, W.R., 1952, Phosphatic rocks in the Deer Creek-Wells 

Canyon area, Idaho: U.S. Geological Survey Bulletin 

982–A, p. A1–A52.

Mabie, D.P., and Hess, H.D., 1964, Petrographic study and 

classification of western phosphate ores: U.S. Bureau of 

Mines Report of Investigations no. 6468, 95 p.

Martindale, S.G., 1986, Depositional environments and 

phosphatization of the Meade Peak Phosphatic Shale 

Tongue of the Phosphoria Formation, Leach Mountains, 

Nevada: University of Wyoming, Contributions to Geology, 

v. 24, no. 2, p. 143–156.

McKee, E.D., Oriel, S.S., and others, 1967, Paleotectonic 

maps of the Permian System: U.S. Geological Survey 

Miscellaneous Geologic Investigations Map I–450, 

scale 1:5,000,000.

McKelvey, V.E., Cressman, E.R., Sheldon, R.P., Cheney, T.M., 

Swanson, R.W., and Williams, J.S., 1959, The Phosphoria, 

Park City, and Shedhorn Formations in the western 

phosphate field: U.S. Geological Survey Professional Paper 

313–A, 47 p.

Merriam, C.W and Hall, W.E., 1957, Pennsylvanian and 

Permian rocks of the southern Inyo Mountains, California: 

U.S. Geological Survey Bulletin 1061–A, p. A1–A13.

Murchey, B.L., 1990, Age and depositional setting of siliceous 

sediments in the upper Paleozoic Havallah sequence near 

Battle Mountain, Nevada; Implications for the paleogeography and structural evolution of the western margin of 

North America, in Harwood, D.S., and Miller, M.M., eds., 

Paleozoic and early Mesozoic paleogeographic relations; 

Sierra Nevada, Klamath Mountains, and related terranes: 

Boulder, Colorado, Geological Society of America Special 

Paper 255, p. 137–155.

Nolan, T.B., 1935, The Gold Hill mining district, Utah: U.S. 

Geological Survey Professional Paper 177, 172 p.

Piper, D.Z., and Link, P.K., 2002, An upwelling model for the 

Phosphoria Sea—A Permian, ocean-margin sea in the northwest United States: American Association of Petroleum 

Geologists, v. 86, no. 7, p. 1217–1235.
20 Mid-Permian Phosphoria Sea in Nevada and the Upwelling Model

Poole, F.G., and Wardlaw, B.R., 1978, Candelaria (Triassic) 

and Diablo (Permian) Formations in southern Toquima 

Range, central Nevada, in Howell, D.G., and McDougall, 

K.A., eds., Mesozoic paleogeography of western United 

States: Society of Economic Paleontologists and Mineralogists, Pacific Section, Pacific Coast Paleogeography Symposium 2, p. 271–276.

Roberts, R.J., 1964, Stratigraphy and structure of the Antler 

Peak quadrangle, Humboldt and Lander Counties, Nevada: 

U.S. Geological Survey Professional Paper 459–A, 93 p.

Rogers, C.L., Kleinhampl, F.J., Ziony, J.I., and Danilchick, 

Walter, 1970, Phosphate occurrences in Nye County and 

adjacent areas, Nevada: U.S. Geological Survey Professional Paper 700–C, p. C49–C60.

Sheldon, R.P., Maughan, E.K., and Cressman, E.R., 1967, 

Paleogeography and sedimentary environments at time of 

maximum transgression during Leonard time in Wyoming 

and adjacent areas, in McKee, E.D., Oriel, S.S., and others, 

1967, Paleotectonic maps of the Permian System: U.S. 

Geological Survey Miscellaneous Geologic Investigations 

Map I–450, plate 11, scale 1:2,500,000.

Sides, J.W., 1966, The geology of the central Butte Mountains, 

White Pine County, Nevada: Palo Alto, Calif., Stanford 

University Ph.D. dissertation.

Silberling, N.J., 1991, Allochthonous terranes of western 

Nevada, current status, in Raines, G.L., Lisle, R.E., Schafer, 

R.W., and Wilkinson, W.H., eds., Geology and Ore deposits 

of the Great Basin: Geological Society of Nevada , Symposium Proceedings, 1990, p. 101–102.

Silberling, N.J., Jones, D.L., Blake, M.C., Jr., and Howell, 

D.G., 1987, Lithotectonic terrane map of the western 

conterminous United States: U.S. Geological Survey 

Miscellaneous Field Studies Map MR–1874–C, scale 

1:2,500,000.

Silberling, N.J., Jones, D.L., Monger, J.W.H., and Coney, P.J., 

1992, Lithotectonic terrane map of the North American 

Cordillera: U.S. Geological Survey Miscellaneous 

Investigations Series Map I–2176, scale 1:5,000,000.

Smith, J.F., Jr., and Ketner, K.B., 1975, Stratigraphy of 

Paleozoic rocks in the Carlin-Pinon Range area, Nevada: 

U.S. Geological Survey Professional Paper 867–A, 87 p.

Smith, J.F., Jr., and Ketner, K.B., 1978, Geologic map of 

the Carlin-Pinon Range area, Elko and Eureka Counties, 

Nevada: U.S. Geological Survey Miscellaneous 

Investigations Map I–1028, scale 1:62,500.

Smith, J.F., Jr., Ketner, K.B., Hernandez, G.X., Harris, A.G., 

Stamm, R.G., and Smith, M.C., 1990, Geologic map of 

the Summer Camp quadrangle, and part of the Black Butte 

quadrangle, Elko County, Nevada: U.S. Geological Survey 

Miscellaneous Investigations Series Map I–2097, scale 

1:24,000.

Snyder, W.S., Spinosa, Claude, and Gallegos, D.M., 1991, 

Pennsylvanian-Permian tectonism on the western U.S. 

continental margin, in Raines, G.L., Lisle, R.E., Schafer, 

R.W., and Wilkinson, W.H., 1991, Geology and ore 

deposits of the Great Basin: Geological Society of Nevada, 

Symposium Proceedings, p. 5–19.

Speed, R.C., MacMillan, J.R., Poole, F.G., and Kleinhampl, 

F.J., 1977, Diablo Formation, central western Nevada: 

composite of deep and shallow water upper Paleozoic 

rocks in Stewart, J.H., Stevens, C.H., and Fritsche, A.E., 

Paleozoic Paleogeography of the Western United States, 

Pacific Coast Paleogeography Symposium 1: Society 

of Economic Paleontologists and Mineralogists, Pacific 

Section, April 22, 1977, p. 301–314.

Stevens, C.H., Stone, Paul, and Miller, J.S., 2005, A new 

reconstruction of the Paleozoic continental margin of 

southwestern North America—Implications for the nature 

and timing of continental truncation and the possible role of 

the Mojave-Sonora megashear, in Anderson, T.H., Nourse, 

J.A., McKee, J.W., and Steiner, M.B., eds., The MojaveSonora megashear hypothesis—Development, assessment, 

and alternatives: Geological Society of America Special 

Paper 393, p. 597–618.

Stone, Paul, and Stevens, C.H., 1988, An angular 

unconformity in the Permian section of east-central 

California: Geological Society of America Bulletin, v. 100, 

p. 547–551.

Tomlinson, A.J., 1990, Biostratigraphy, stratigraphy, 

sedimentary petrology, and structural geology of the upper 

Paleozoic Golconda allochthon, north-central Nevada: Palo 

Alto, Calif., Stanford University, Ph.D. dissertation, 492 p.

Trappe, Jörg, 2001, A nomenclature system for granular 

phosphate rocks according to depositional texture: 

Sedimentary Geology, v. 145, p. 135–150.

Tschantz, C.M., and Pampeyan, E.H., 1970, Geology and 

mineral deposits of Lincoln County, Nevada: Nevada 

Bureau of Mines, Bulletin 73, 187 p.

Wardlaw, B.R., Collinson, J.W., and Maughan, E.K., 1979, 

The Murdock Mountain Formation—A new unit of 

the Permian Park City Group: U.S. Geological Survey 

Professional Paper 1163–B, p. 5–8.
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Whitebread, D.H., 1994, Geologic map of the Dun Glen 

quadrangle, Pershing County, Nevada: U.S. Geological 

Survey Miscellaneous Investigations Series Map I–2409, 

scale 1:48,000.

Wyld, S.J., 1990, Paleozoic and Mesozoic rocks of the Pine 

Forest Range, northwest Nevada, and their relation to 

volcanic arc assemblages of the western U.S. Cordillera, 

in Harwood, D.S., and Miller, M.M., eds., Paleozoic and 

early Mesozoic paleogeographic relations; Sierra Nevada, 

Klamath Mountains, and related terranes: Geological 

Society of America Special Paper 255, p. 219–237.

References Cited 21
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