Upper Devonian to Upper Mississippian Strata 

of the Antler Foreland in the Leppy Hills, 

Easternmost Northern Nevada

U.S. GEOLOGICAL SURVEY BULLETIN 1988-G
AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY

Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the current-year 

issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Survey publications released prior to the current year are listed in the most recent annual "Price and Availability List." Publications that may be listed in various U.S. 

Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and Availability List" may no longer be 

available.

Reports released through the NTIS may be obtained by writing to the National Technical Information Service, U.S. Department of 

Commerce, Springfield, VA 22161; please include NTIS report number with inquiry.

Order U.S. Geological Survey publications by mail or over the counter from the offices listed below.

BY MAIL

Books

Professional Papers, Bulletins, Water-Supply Papers, Techniques of Water-Resources Investigations, Circulars, publications 

of general interest (such as leaflets, pamphlets, booklets), single 

copies of Earthquakes & Volcanoes, Preliminary Determination of 

Epicenters, and some miscellaneous reports, including some of the 

foregoing series that have gone out of print at the Superintendent of 

Documents, are obtainable by mail from

U.S. Geological Survey, Map Distribution

Box 25286, MS 306, Federal Center

Denver, CO 80225

Subscriptions to periodicals (Earthquakes & Volcanoes and 

Preliminary Determination of Epicenters) can be obtained ONLY 

from the

Superintendent of Documents

Government Printing Office

Washington, DC 20402

(Check or money order must be payable to Superintendent of 

Documents.)

Maps

For maps, address mail orders to

U. S. Geological Survey, Map Distribution

Box 25286, BIdg. 810, Federal Center

Denver, CO 80225

Residents of Alaska may order maps from

U.S. Geological Survey, Earth Science Information Center

101 Twelfth Ave., Box 12

Fairbanks, AK 99701

OVER THE COUNTER

Books and Maps

Books and maps of the U.S. Geological Survey are available 

over the counter at the following U.S. Geological Survey offices, all 

of which are authorized agents of the Superintendent of Documents.

 ANCHORAGE, Alaska-Rm. 101,4230 University Dr.

 LAKEWOOD, Colorado-Federal Center, Bldg. 810

 MENLO PARK, California-Bldg. 3, Rm. 3128, 

345 Middlefield Rd.

 RESTON, Virginia-USGS National Center, Rm. 1C402, 

12201 Sunrise Valley Dr.

 SALT LAKE CITY, Utah-Federal Bldg., Rm. 8105, 

125 South State St.

 SPOKANE, Washington-U.S. Post Office Bldg., Rm. 135, 

West 904 Riverside Ave.

 WASHINGTON, D.C.-Main Interior Bldg., Rm. 2650, 

18th and C Sts., NW.

Maps Only

Maps may be purchased over the counter at the following 

U.S. Geological Survey offices:

 FAIRBANKS, Alaska-New Federal Bldg, 101 Twelfth Ave.

 ROLLA, Missouri-1400 Independence Rd.

 STENNIS SPACE CENTER, Mississippi-Bldg. 3101
Upper Devonian to Upper Mississippian Strata 

of the Antler Foreland in the Leppy Hills, 

Easternmost Northern Nevada

By K.M. Nichols and N. J. Silberling

EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN 

Harry E. Cook and Christopher J. Potter, Project Coordinators

U.S. GEOLOGICAL SURVEY BULLETIN 1988-G

A multidisciplinary approach to research studies of sedimentary 

rocks and their constituents and the evolution of 

sedimentary basins, both ancient and modern

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1993
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Robert M. Hirsch, Acting Director

For sale by

USGS Map Distribution

Box 25286, Building 810

Denver Federal Center

Denver, CO 80225

Any use of trade, product, or firm names in this publication is for descriptive purposes only and 

does not imply endorsement by the U.S. Government.

Library of Congress Cataloging-in-Publication Data

Nichols, K.M. (Kathryn Marion), 1946-

Upper Devonian to Upper Mississippian strata of the Antler foreland in the Leppy Hills, easternmost northern Nevada / by K.M. 

Nichols and N.J. Silberling.

p. cm. (Evolution of sedimentary basins Eastern Great Basin ; ch. G) (U.S. Geological Survey bulletin; 1988)

Includes bibliographical references.

Supt.ofDocs.no.: I 19.3:1988-G

1. Geology, Stratigraphic Devonian. 2. Geology, Stratigraphic Mississippian. 3. Geology Nevada Leppy Hills 

Region.

I. Silberling, N.J. (Norman John), 1928- . II. Title. III. Series. IV. Series: U.S. Geological Survey bulletin; 1988. 

QE75.B9 no. 2023-G 

[QE665]

557.3 s dc20 93-10960 

[551.7'4'09793] CIP
CONTENTS

Abstract................................................................................................................................. Gl

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

Stratigraphy........................................................................................................................... 2

Pilot Shale................................................................................................................... 2

Joana Limestone......................................................................................................... 5

Needle Siltstone Member of the Chainman Shale...................................................... 9

Structure................................................................................................................................ 10

Paleotectonic Implications.................................................................................................... 11

References Cited................................................................................................................... 13

FIGURES

1-3. Maps showing:

1. Location of Leppy Hills area......................................................................................................................... G2

2. Location of Leppy Hills and other localities referred to in text..................................................................... 3

3. Topography of part of Leppy Hills area and locations of sections A and B.................................................. 4

4. Photographs of section A, upper A-l Canyon........................................................................................................ 5

5, 6. Columnar sections:

5. Section A........................................................................................................................................................ 6

6. Section B ............................................................. 7

7. Photograph of characteristic outcrop of dolomitic siltstone of Pilot Shale............................................................. 7

8. Photomicrographs of dolomitic siltstone of Pilot Shale.......................................................................................... 8

9-15. Photographs of:

9. Limestone bed displaying Bouma-sequence layering, Pilot Shale................................................................ 8

10. Limestone bed displaying Bouma-sequence layering, Pilot Shale................................................................ 8

11. Carbonate-cemented siltstone showing plane-bed lamination, Pilot Shale................................................... 9

12. Dolomitic siltstone showing possible hummocky cross stratification, Pilot Shale........................................ 9

13. Local angular discordance at faulted contact between Joana Limestone and Pilot Shale............................. 9

14. Concordant but faulted contact between Joana Limestone and Pilot Shale................................................... 10

15. Nodular cherty limestone, basal part of Joana Limestone............................................................................. 10

16. Photomicrograph of bioclastic wackestone, lower unit of Joana Limestone.......................................................... 10

17. Photograph showing crinoid-rich stringers in peloidal packstone, middle unit of Joana Limestone..................... 11

18. Photomicrographs of peloidal bioclastic packstone, middle unit of Joana Limestone........................................... 11

19, 20. Photographs of:

19. Oncolites near top of JoanaLimestone.......................................................................................................... 12

20. Solution-compacted bioclastic wackestone near top of JoanaLimestone..................................................... 12

21. Photomicrograph of solution-compacted limestone in uppermost part of Joana Limestone.................................. 12

22. Photograph of contact between Joana Limestone and Needle Siltstone Member of the Chainman Shale............. 12

in

Upper Devonian to Upper Mississippian Strata

of the Antler Foreland in the Leppy Hills,

Easternmost Northern Nevada

By K.M. Nichols and N.J. Silberling

ABSTRACT

Upper Devonian to Upper Mississippian strata in the 

Leppy Hills, easternmost northern Nevada, represent, in 

ascending order, rock units whose formal names, albeit 

somewhat misleading, are the Guilmette Formation, Pilot 

Shale, Joana Limestone, and Needle Siltstone Member of the 

Chainman Shale. In the Leppy Hills study area, both the 

upper and lower contacts of the Pilot Shale are bedding-subparallel, attenuational faults; other such faults may be 

present within the Pilot and also could be present between 

the Needle Siltstone Member and higher parts of the 

Chainman Shale.

The Pilot Shale in the study area closely resembles the 

lower part of the Pilot elsewhere in the eastern Great Basin 

and is mostly laminated, secondarily dolomitic siltstone that 

includes a distinctive interval of intercalated Boumasequence limestone. Strata of the Pilot Shale can be interpreted as storm deposits formed on the ramp of a restricted 

intrashelf subsident area.

The Joana Limestone in the Leppy Hills study area is 

anomalously thin and probably correlates with only the basal 

part of the Joana, as this name is applied, in ranges farther to 

the south. In the Leppy Hills the Joana is disconformably 

overlain by dolomitic siltstone of the Needle Siltstone Member whose character reflects sedimentation during the Delle 

phosphatic event.

The relatively weak lithic expression of the onset of the 

Delle phosphatic event in the Leppy Hills study area, and the 

evidently greater age of the uppermost part of the Joana 

Limestone here, as compared with sections in west-central 

Utah, is of significance for interpreting the flexural-loading 

paleotectonics of the Antler foreland. In the Leppy Hills 

study area a distinct disconformity separates the Needle Siltstone Member, the base of which corresponds to the advent 

of the Delle phosphatic event, from the Joana Limestone. 

Mississippian strata in this area may therefore record deposition on the previously hypothesized Antler foreland bulge. 

The existence of such a feature has been called upon to

explain the peculiar anoxic nature of strata formed farther to 

the east, in the backbulge region of the foreland, under the 

influence of the Delle phosphatic event.

INTRODUCTION

The Upper Devonian to Upper Mississippian section 

in the Leppy Hills, just north of the town of Wendover on 

the Nevada-Utah State line (fig. 1), provides a strategically located reference point for regional interpretation of 

the depositional history of the Antler foreland in the eastem Great Basin. Exposures of these rocks are the northernmost of the succession that is characteristic of the 

Antler foreland for several hundred kilometers to the south 

in easternmost Nevada and westernmost Utah. This succession includes, in ascending order, the Pilot Shale, limestones collectively referred to the Joana Limestone, and 

the Needle Siltstone Member forming the basal part of the 

Chainman Shale. 1 Although the Pilot through Needle succession in the Leppy Hills is incomplete owing to bedding-subparallel, attenuational faulting, as described later, 

the contact of the Needle Siltstone Member with the 

underlying Joana Limestone is disconformable, preserving 

a weak, but incontrovertible record of the onset of the 

Delle phosphatic event (Silberling and Nichols, 1990, 

1991), the effects of which are best represented at localities in west-central Utah such as the Lakeside Mountains 

(fig. 2) (Sandberg and Gutschick, 1984; Nichols and Silberling, 1990). This disconformable contact provides a 

datum that allows the unusually thin Joana Limestone in 

the Leppy Hills to be contrasted with the much thicker 

sections of Lower Mississippian pre-Delle phosphatic

'Note that although the term "shale" is used as part of the regional 

name for both the Pilot Shale and the Chainman Shale, this lithic identification is not descriptive of the specific parts of these units discussed in this 

report.

Gl
G2 EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

loREGON; IDAHO (_. ._i_. -__^

114°

r\ Newfoundland 

| ) Mountains

Figure 1. Index map of northeastern Nevada and northwestern Utah showing the location of the Leppy Hills area. Modified from 

Schneyer (1984).

event limestone farther to the south and east in Nevada 

and Utah. Consequently, the Leppy Hills section has an 

important bearing on regional paleogeography and the 

applicability of flexural-loading models to explain the 

shifting pattern of uplift and subsidence in the late 

Paleozoic Antler foreland.

STRATIGRAPHY

Parts of the Pilot Shale, Joana Limestone, and Needle 

Siltstone Member and younger members of the Chainman 

Shale are fairly well exposed near the head of A-l Canyon in the Leppy Hills. Much of the section was measured 

twice on adjacent minor spurs on the west side of the canyon in order to place the discontinuous exposures in the 

same stratigraphic context. The northern and southern of 

these parallel sections are designated respectively sections 

A and B; their locations are shown on figure 3, and the 

nature of the exposures at section A is shown in figure 4.

PILOT SHALE

The areal distribution of the rocks assigned to the Pilot 

Shale in the study area is shown on the map of the Leppy 

Hills by Schneyer (1990), who interpreted the contact

between the Pilot and underlying Guilmette Formation in 

the headwaters of A-l Canyon as a bedding-subparallel, 

attenuational fault marked by a zone of brecciation and 

silicification. Although the amount of missing section is 

unknown, the youngest limestone beds of the Guilmette 

here are thin-parted, mottled, pelletal-skeletal packstone 

containing abundant open-marine bioclasts such as echinoderm ossicles. These limestones lithically resemble those, 

in sections farther to the south in easternmost Nevada and 

westernmost Utah, that either constitute a distinctive rock 

unit forming the uppermost part of the Guilmette or are 

recognized as a separate formation the West Range Limestone intervening between the Guilmette and Pilot. 

Because of this and because of the nature of the older part 

of the Pilot in A-l Canyon, as described later, the thickness 

of omitted strata is probably not great.

The upper contact of the Pilot Shale with the overlying Joana Limestone is also a bedding-subparallel fault, as 

shown by the omission of at least a few meters of the 

basal part of the Joana along strike between sections A 

and B (figs. 5, 6). The amount of the Pilot cut out on this 

fault is unknown. The several-meter difference in thickness of the limestone-rich and higher parts of the Pilot 

between sections A and B, which are only about 200 m 

apart, could be attributed to attenuation on this fault or 

others within poorly exposed parts of the Pilot section, or 

it could simply reflect the imprecision in section
UPPER DEVONIAN TO MISSISSIPPIAN STRATA, LEPPY HILLS G3

116° 114° 112 C

42C

38°

NEVADA

EASTERN LIMIT OFROBERTS MOUNTAINS/

ALLOCHTHON

Leppy 

Hills

IDAHO

UTAH

Lakeside

Mountains

x

Wendover 0 Salt Lake 

City

East Tintic 

District

0 Ely

Ward X 

Mountain

I x Confusion Range

I x Burbank Hills 

! x Needle Range

Pahranagat

Range

x

III

50 100 KILOMETERS 

I i I

Figure 2. Map of eastern Nevada and western Utah showing the 

location of the Leppy Hills and other localities referred to in text 

(marked by X's). The eastern limit of the Roberts Mountains allochthon is controlled by its original eastward thrust emplacement 

onto the continental margin during Antler orogenesis as well as by 

subsequent contractional and extensional tectonism.

measuring. The minimum thickness of the Pilot in upper 

A-l Canyon is about 130 m.

Most of the Pilot Shale in A-l Canyon is generally 

recessive, dolomitic siltstone to very fine grained sandstone 

having conspicuously planar lamination and parting (fig. 

7). These rocks are black on fresh surfaces and mostly 

weather grayish orange to yellowish orange, less commonly 

very pale orange or pale red. In less fissile parts of the 

section, the matrix of subhedral secondary dolomite crystals in places supports detrital quartz grains, and at least 

some laminae are silty dolostone (fig. 8). The laminated 

siltstone is variably calcitic owing either to incomplete 

replacement by dolomite of original lime-mud matrix or to 

dedolomitization. More fissile parts of the clastic section 

are shaly and have less carbonate cement. In addition to 

quartz, trace amounts of white mica and plagioclase are 

present among the detrital terrigenous-clastic grains.

The principal lithic variation within the succession of 

laminated siltstone is the occurrence of discrete limestone 

interbeds through an interval about 30 m thick that is best 

exposed in the lower part of section B (fig. 6). These 

limestone beds are about 10-40 cm thick, are for the most 

part intercalated in the resident dolomitic siltstone 

(although some limestone beds are composite), and

display the internal Bouma sequences T&A, AB, ABC, and 

ABCE (fig. 9) (Poole, 1974, fig. 7b). The thickest and 

most coarse grained limestone beds are among the stratigraphically highest. In these, the TfcA layer forms most of 

the bed and is bipartite, consisting of a poorly sorted, 

coarsely intraclastic lower part overlain abruptly by distinctly finer grained, but graded, quartz-sandy limestone 

(for example, fig. 10). One such bed contains in its lower 

part individual tabular clasts, as long as 18 cm, of various 

types of limestone including bioclastic wackestone and 

distinctly laminated packstone. These clasts are in a matrix 

of smaller intraclasts and sandy limestone containing 

coarse quartz grains. The composition of the intraclasts 

suggests their origin by the rip-up of related, previously 

deposited limestone beds, although the coarse, wellrounded quartz sand and bioclasts are exotic to the local 

Pilot section.

Above the part of the Pilot in A-l Canyon characterized by limestone interbeds is 40-45 m of the Pilot Shale 

that, although only partly exposed, is apparently wholly 

composed of more or less carbonate-cemented siltstone 

resembling the siltstones beneath the limestone. These siltstone beds exhibit the same characteristic even lamination 

(fig. 11), although some are distinctly more shaly and fissile. About 3 m below the top of the Pilot in section A, 

low-angle truncation of the siltstone laminae is suggestive 

of hummocky cross stratification (fig. 12).

Neither body fossils nor feeding tracks were observed 

in the siltstone of the Pilot Shale in A-l Canyon, suggesting relatively oxygen deficient conditions during sedimentation. In keeping with this inference, the pervasive 

secondary dolomitization of the original carbonate cement 

or matrix of the siltstone may have been induced by a 

reducing diagenetic environment.

In comparison with other sections of the Pilot Shale 

in the eastern Great Basin, the Pilot Shale in the Leppy 

Hills probably represents the relatively older part of the 

Pilot. Discrete limestone beds having well-defined Boumasequence layers are characteristic of the lower part of the 

Pilot in, for example, the Cherry Creek, Confusion, and 

Pahranagat Ranges (fig. 2). Conodonts from the TjjE layer 

of one of these limestone beds in section B in A-l Canyon, about 10 m above the limestone bed illustrated by 

figure 9 and located stratigraphically on figure 6, are 

reported by R.G. Stamm (U.S. Geological Survey, written 

commun., 1991) to be palmatolepids of early Frasnian to 

middle Famennian age, thus supporting this lithic 

correlation.

Rocks of the Pilot Shale elsewhere in the eastern 

Great Basin that are lithically similar to those in the 

Leppy Hills are commonly interpreted to be deep-marine, 

turbiditic deposits (for example, Sandberg and others, 

1989, p. 198), but the implication of sediment transport 

and deposition by gravity-driven flows is open to question. The general character and stratigraphic context of
G4 EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

114°04'

40°41'

0.5 

I

1 KILOMETER 

J

Figure 3. Topographic map of the part of the Leppy Hills showing the area of the upper part of A-1 Canyon in the Leppy Hills, northeastern Nevada. The locations of sections A and B (figs. 5 and 6, respectively) are also shown. Base is the Leppy Peak l:24,000-scale 

quadrangle (contour interval 20 and 40 ft).

the secondarily dolomitic, fine-grained clastic rocks of turbiditelike Bouma-sequence limestone beds in the Pilot

the Pilot Shale do not suggest deposition in a slope or of easternmost Nevada and westernmost Utah are

deep basin environment, and gravity-flow structures such regarded by us as primarily storm deposits or tempestites.

as slump folds are absent in these deposits. The rare Although the transport of their finer grained constituents
UPPER DEVONIAN TO MISSISSIPPIAN STRATA, LEPPY HILLS G5

Men

Figure 4. Photographs showing section A in upper A-l Canyon, northeastern Nevada. Location of section A is shown in figure 3. Dp, 

Upper Devonian part of Pilot Shale; Mj, Lower Mississippian Joana Limestone; Men, Mississippian Needle Siltstone Member of the Chainman Shale (the Needle is recognized as including Lower and Upper Mississippian rocks where it is reported in other areas, Poole and Sandberg, 1991). Cliffy exposures of unit Mj are about 5 m high. A, View looking northwest across upper A-l Canyon toward section A. Note 

power-line pole at right center. B, View looking north along strike across upper part of section A toward the power-line pole shown in A.

may have had some component of turbidity-current flow 

in addition to storm-generated combined flow, we believe 

that storm activity was initially responsible for putting 

this sediment into suspension. Water depths during Pilot 

deposition need only to have been sufficiently deep to 

maintain a reducing environment, and in the absence of 

slope deposits these conditions could be met at shallow 

depths, for example, in a paralic system.

JOANA LIMESTONE

The relatively thin unit of limestone intervening 

between siltstone of the Pilot Shale and siltstone of the 

Needle Siltstone Member of the Chainman Shale in A-l 

Canyon is referred to the Joana Limestone following 

Schneyer (1990). The thickness of the Joana ranges from 

5 to 7 m in the exposures in upper A-l Canyon because 

of the local truncation of section on an attenuational 

fault at its base. Mild disruption of layering in siltstone 

of the Pilot immediately below this fault is apparent 

where this part of the section is well exposed in section 

A (figs. 13, 14).

Three lithic units comprise the Joana Limestone in 

sections A and B: (1) a lower unit of nodular, distinctly 

bedded, cherty packstone and wackestone, (2) a middle 

unit of massive, peloidal, crinoidal packstone and grainstone, and (3) an upper unit of oncolitic bioclastic wackestone and subordinate packstone.

As much as 3.5 m of the lower unit of nodular limestone is locally preserved above the fault at the base of the 

Joana Limestone. Rocks of this unit are distinctly mottled 

or nodular in thin to medium beds that are separated by

irregular partings of fine-grained siliciclastic impurities 

that form the locus of blebs and stringers of dark-colored 

secondary chert (figs. 13-15). In thin section (fig. 16), the 

limestone of this interval is composed of irregularly intermixed patches of finely bioclastic packstone and wackestone. As much as several meters of similar limestone 

characteristically is present in the basal parts of Lower 

Mississippian limestone units elsewhere in eastern Nevada 

and western Utah where these units disconformably overlie fine-grained clastic rocks of the Pilot Shale. For this 

reason, we believe that at most only a few meters of the 

lower unit of the Joana is cut out by faulting in the vicinity of sections A and B.

The main, middle unit of the Joana Limestone consists of about 4 m of massively bedded peloidal and 

crinoidal packstone and grainstone mixed together in 

irregular patches and stringers (figs. 17, 18). Calcite veinlets in these rocks fill a complicated network of fractures 

and small-scale faults, and the limestone itself is greatly 

solution compacted and stylolitized.

The upper unit of the Joana Limestone is 0.5-1.0 m 

thick. It is gradational with the middle unit but is characterized by scattered oncolites in beds of massive wackestone (fig. 19). The uppermost few tens of centimeters of 

limestone, as observed both megascopically and in thin 

section, are extensively dissolved and solution compacted 

(figs. 20, 21) beneath the rocks of the Needle Siltstone 

Member of the Chainman Shale, the base of which manifests the onset of the Delle phosphatic event. For just a 

few meters along strike at section A, the solution-compacted limestone at the top of the Joana is completely 

exposed and is irregularly replaced by 10-20 cm of massive black chert, at the top of which is a discontinuous
G6 EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

METERS 

160 

to 03

O

r=-Q

v> £

0) CD =5^

CD 

CD

140

Joana Limestone

120 

100 

80 

Pilot Shale

60 

40 

20 

Guilmette 

Formation (part)

0 :

Unexposed

Unexposed

Fault (?) 

Highest float of

Needle Siltstone

Member

Fjgure 22 

Figures 19 and 21

Figures 13 and 14 

Fault

Figure 12

Fault 

Figure 11

Fault

Base of limestonebed interval

Figure 8

Figure 7

Fault

Medium- to coarse-grained, partly planar laminated, quartz-chert 

sandstone

Slabby to planar-laminated, dolomitic siltstone, mainly weathering 

grayish to yellowish orange; sporadic phosphatic nodules

Massive, peloid-crinoid packstone-grainstone; oncolitic wackestonepackstone near top. At top, as much as 20 cm of black replacement 

chert with crust of phosphate pellets

Nodular, bedded, cherty packstone-wackestone

Planar-laminated to fissile, carbonate (mainly dolomite)-cemented 

siltstone and shaly siltstone; characteristically weathering grayish 

orange to yellowish orange

Individual or composite, 10-to 40-cm-thick limestone beds exhibiting 

internal Bouma-sequence layering; intercalated in dolomitic siltstone

Planar-laminated to slabby, dolomitic siltstone and very fine grained 

sandstone, minor silty secondary dolomite; black on fresh surfaces; 

characteristically weathering grayish orange to yellowish orange

Thin-parted, mottled, pelletal skeletal packstone containing 

open-marine bioclasts such as echinoderm ossicles

Figure 5. Columnar section of section A. Location of study section is shown in figure 3.
UPPER DEVONIAN TO MISSISSIPPIAN STRATA, LEPPY HILLS G7

METERS

80 

Joana 

Limestone

60 

40 

Pilot Shale 

(part)

20 

0 

Unexposed

, Figure 20

 Figures 17 

and 18 

Figures 15 

and 16

Massive, peloid-crinoid 

packstone-grainstone

Nodular, bedded, cherty 

packstone-wackestone

Unexposed

Planar-laminated dolomitic 

siltstone, similar to 

lowermost unit

Figure 10

Unexposed

Individual or composite, 

10-to 40-cm-thick 

limestone beds exhibiting 

internal Bouma-sequence 

layering; intercalated in 

dolomitic siltstone

1 cr1 Figure 9

 "" 1^3

Planar-laminated to slabby, 

dolomitic siltstone and 

very fine grained sandstone, 

minor silty secondary 

dolomite; black on fresh 

surfaces; characteristically 

weathering grayish orange 

to yellowish orange

Figure 6. Columnar section of section B. Location of study 

section is shown in figure 3.

layer of phosphate peloids as much as a centimeter thick 

(fig. 22). Laminated dolomitic siltstone of the Needle Siltstone Member crops out within 20 cm above the layer of 

phosphate peloids. The progressively intense solution 

compaction toward the top of the Joana Limestone, the 

replacement of limestone by chert, and the appearance of 

pelletal phosphate grains are all characteristic diagenetic 

effects of the onset of the Delle phosphatic event on preexisting carbonate rocks (Nichols and Silberling, 1990; 

Silberling and Nichols, 1991).

«? f:~ >*&±£$si£z*iK --^"-w-'r-" ^si"*-^*.-^* . ,. j^s _ £ f" -. *atsaf * J5* * ^"*" -^^ -* i

-taut*- *~~

Figure 7. Characteristic outcrop of dolomitic siltstone of the Pilot Shale. Strata are thinly laminated, platy weathering, and grayish 

orange to yellowish orange. Section A, 20 m above (faulted) base, 

upper A-l Canyon, northeastern Nevada. Location of section is 

shown in figure 3. Hammer handle about 40 cm long.

The three depositional units forming the unusually 

thin section of the Joana Limestone in A-l Canyon represent a single shallowing-upward cycle. Forming the basal 

part of this cycle is bedded, subtidal, offshore ramp limestone of the lower unit overlain by massive peloid-crinoid 

shoal deposits of the middle unit that in turn grade up into 

oncolitic peritidal limestone in the upper unit. Accepting 

that the faulted remnant of the lower unit is representative 

of the rocks originally forming the basal part of the limestone section, the Joana of A-l Canyon resembles the 

basal parts of the formation in the few reasonably complete, nearby sections to the south. For example, in the 

Red Hills (fig. 2) two successive upward-shoaling cycles 

comprising limestone similar in character to that of the 

Joana in the Leppy Hills form the initial Joana deposits of 

the Kinderhookian transgression over the disconfbrmably 

underlying Pilot Shale. On the basis of conodonts from its 

uppermost beds, the Joana in A-l Canyon was assigned a 

late Kinderhookian age by Newman (1980), and the age of 

our collections from the middle and upper units of the section was similarly interpreted by R.G. Stamm (U.S. Geological Survey, written commun., 1991), primarily on the 

basis of conodonts of the genus Patrognathus. Thus, both 

lithic and conodont-based-paleontologic correlations indicate that the Joana at A-l Canyon represents only the 

lowermost part of the Joana in terms of the much thicker 

Joana sections that are present farther to the south in easternmost Nevada and westernmost Utah and that span the 

upper Kinderhookian and the lower Osagean.

Assignment of the Lower Mississippian limestone 

beds in the Leppy Hills to the Joana Limestone (see 

Schneyer, 1990) can be justified only in the sense that all 

carbonate rocks of this general age that intervene between 

the Pilot Shale and Chainman Shale in easternmost
G8 EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

Figure 8. Photomicrographs of dolomitic siltstone of the Pilot Shale. Section A, 45 m above base, upper A-l Canyon, northeastern Nevada. Location of section is shown on figure 3. Note dolomite euhedra (d) and mica flakes (m) in center of B. Bar scales, 0.5 mm.

Figure 9. Isolated limestone bed in the Pilot Shale displaying 

Bouma sequence ABCE and grading from coarsely quartz-sandy 

limestone at base to lime mudstone at top. T^C foresets dip approximately due south. Section B, 3 m above base, upper part of A-l 

Canyon, northeastern Nevada. Location of section is shown in 

figure 3. Pencil for scale.

^'is^r^i.tf

Figure 10. Upper part of an isolated limestone bed in the Pilot 

Shale displaying Bouma sequence AB. Note poor sorting of limestone intraclasts forming base of the T&A layer and their abrupt 

contact with the massive, graded packstone forming the upper part 

of this layer. Section B, 32 m above base, upper part of A-l 

Canyon, northeastern Nevada. Location of section is shown in 

figure 3. Pencil for scale.

Nevada and adjacent Utah are customarily so referred. 

Few, if any, of the lithically diverse carbonate-rock units 

that regionally comprise the various sections presently 

referred to the Joana can be demonstrated to have genetic 

counterparts in the typical reference section of the Joana at 

Ward Mountain south of Ely, Nevada (fig. 2). Rocks currently called the Joana Limestone in the Confusion Range, 

Burbank Hills, and Needle Range in westernmost Utah 

(fig. 2), all formerly termed the Midridge Limestone by

Bacon (1948) and Ogden (1951), have more in common in 

terms of their included carbonate units and sequence 

stratigraphy with the Fitchville Formation and Gardison 

Limestone of the East Tintic district in west-central Utah 

(fig. 2) than with the typical Joana of the Ely district in 

Nevada. Resolution of this nomenclatural problem is 

beyond the scope of this paper, but for paleotectonic 

interpretation it is important that the Fitchville in Utah 

either includes a complete stratigraphic sequence or is in
UPPER DEVONIAN TO MISSISSIPPIAN STRATA, LEPPY HILLS G9

Figure 11. Carbonate-cemented (by dolomite and by calcite 

formed by dedolomitization?) siltstone of the Pilot Shale showing 

ubiquitous plane-bed lamination; black on fresh surfaces, weathering to very pale orange. Section A, 96 m above base, upper A-l 

Canyon, northeastern Nevada. Location of section is shown in figure 3. Pencil for scale.

itself a complete cycle. The overlying Gardison forms 

only the lower part of the ensuing sequence in which 

deposits of the Delle phosphatic event, such as the Needle 

Siltstone Member of the Chainman Shale, represent the 

transgressive systems tract (Silberling and Nichols, 1992). 

The limestone assigned to the Joana in the Leppy Hills 

belongs to the same regional stratigraphic sequence as the 

Fitchville and the lower parts of the various sections customarily referred to the Joana elsewhere in eastern Nevada 

and westernmost Utah.

NEEDLE SILTSTONE MEMBER OF THE 

CHAINMAN SHALE

In the Leppy Hills, the rocks assigned to the Joana 

Limestone by Schneyer (1990) are disconformably

Figure 12. Dolomitic siltstone of the Pilot Shale showing bedding lamination suggestive of hummocky cross stratification. Section A, 3 m below (faulted) top of Pilot Shale, upper A-l Canyon, 

northeastern Nevada. Location of section is shown in figure 3. 

Pencil for scale.

Figure 13. Local angular discordance resulting from disruption 

beneath the faulted contact between the Joana Limestone and underlying siltstone of the Pilot Shale. Section A, upper A-l Canyon, 

northeastern Nevada. Location of section is shown in figure 3. 

Hammer handle is about 40 cm long.

overlain by a minimum of 19 m of dolomitic siltstone in 

section A (fig. 5). These siliciclastic rocks are very similar to those forming most of the typical Needle Siltstone 

Member of the Chainman Shale in the Needle Range 

(fig. 2) and the Needle elsewhere in western Utah and 

eastern Nevada. Like the siltstone strata of the older Pilot 

Shale, these rocks are planar-laminated to irregularly 

platy, secondarily dolomitic siltstone that mostly weathers 

yellowish orange to grayish orange. Unlike siltstone strata 

of the Pilot, siltstone strata of the Needle have abundant 

bedding-parallel feeding tracks on some surfaces, and 

phosphate nodules as large as a few centimeters are
G10 EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

Figure 14. Concordant but faulted contact between limestone of 

the Joana Limestone and underlying siltstone of the Pilot Shale 

about 5 m to the south along strike from view in figure 12. Hammer 

handle is about 40 cm long.

sporadically enclosed in the siltstone. Dolomitic siltstone, 

such as in the Needle, is characteristic of deposition 

during the Delle phosphatic event, even though layered 

phosphate in the Leppy Hills is restricted to the thin crust 

of phosphate peloids capping the diagenetically altered 

uppermost part of the Joana Limestone in section A. 

Intervals of ostracode lime mudstone (Silberling and 

Nichols, 1991) or dense, featureless, micritic limestone 

that are a subordinate, but conspicuous, characteristic of 

the Delle phosphatic event elsewhere in Utah and eastern 

Nevada are not present in A-l Canyon.

In section A, above the Needle Siltstone Member but 

separated from it by a covered interval equivalent to about 

10 m of section, medium- to coarse-grained, partly planar 

laminated, quartzitic chert sandstone crops out on the tip 

of the small hill atop which both fairly continuous exposures and section A end. A fault omitting a significant 

thickness of section here could intervene between the

Figure 15. Thin-bedded, nodular, cherty limestone having irregular, calcareous fine-grained siliciclastic partings between bed. 

Section B, upper A-l Canyon, northeastern Nevada. Location of 

section is shown in figure 3. Characteristic of unit as much as 3.5 m 

thick forming basal part of the Joana Limestone. Pencil for scale.

Figure 16. Photomicrograph of bioclastic wackestone in the lower unit of the Joana Limestone. Section B, upper A-l Canyon, 

northeastern Nevada. Location of section is shown in figure 3. Bar 

scale, 0.5 mm.

Needle and the chert-quartz sandstone representing a 

higher part of the Chainman Shale.

STRUCTURE

The structure of A-l Canyon and the Leppy Hills 

area, as described by Schneyer (1984), is dominated by
UPPER DEVONIAN TO MISSISSIPPIAN STRATA, LEPPY HILLS Gil

Figure 17. Fresh outcrop face of the middle unit of the Joana 

Limestone showing crinoid-rich stringers in peloidal packstone, 3.5 

m above local base of the Joana. Section B, upper A-l Canyon, 

northeastern Nevada. Location of section is shown in figure 3. Pencil for scale.

extensional faulting of Cenozoic age. Throughout the area 

"* * * the Chainman Shale and older units are thinned 

primarily by faulting [so that] all paleogeographic 

reconstructions based upon variations in formation thickness are uncertain" (Schneyer, 1984, p. 93). In the local 

area of sections A and B in upper A-l Canyon, the style 

of observed faulting is the cutting out of section along 

bedding-subparallel faults that commonly form the contacts between units of contrasting competency (as, for 

example, between the Guilmette Formation and Pilot 

Shale, and the Pilot Shale and Joana Limestone). These 

faults are thought by us to be generally minor normal 

faults that formed in response to dominolike tilting of the 

slablike stratigraphic units above a master low-angle 

detachment, which in this case would be rooted to the 

east. This style of omissional faulting is observed throughout the eastern Great Basin in this same part of the upper 

Paleozoic stratigraphic section.

Figure 18. Photomicrographs of peloidal, bioclastic packstone 

from the middle unit of the Joana Limestone, 3.5 m above local 

base of the Joana. Section B, upper A-l Canyon, northeastern Nevada. Location of section is shown in figure 3. Highly micritized 

rim of conspicuous crinoid columnal (center right, photomicrograph B) suggests that some peloids may be totally micritized bioclasts. Bar scales, 0.5 mm.

PALEOTECTONIC IMPLICATIONS

Despite the prevalence of attenuational faulting in the 

study area, as described previously, the Joana Limestone 

is in depositional contact with the overlying Needle Siltstone Member of the Chainman Shale; fault omission of
G12 EVOLUTION OF SEDIMENTARY BASINS EASTERN GREAT BASIN

Figure 19. Oncolites 0.5 m below the top of the Joana Limestone. 

Section A, upper A-l Canyon, northeastern Nevada. Location of 

section is shown in figure 3. Pencil for scale.

Figure 20. Solution-compacted bioclastic wackestone or packstone near the top of the Joana Limestone. Section B, upper A-l 

Canyon, northeastern Nevada. Location of section is shown in figure 3. Pencil for scale.

strata at the base of the Joana is minor. Thus, only a relatively very thin Joana section, representing just an erosional remnant of what regionally would be its late 

Kinderhookian basal part, is disconformably preserved 

beneath the Needle, the older age limit for which from 

regional correlations is middle Osagean or younger. 

Moreover, aside from the return to oxygen-deficient depositional conditions indicated by the phosphate-nodule-bearing, dolomitic siltstone of the Needle, the expression of 

the Delle phosphatic event is relatively weak in the basal 

part of the Needle in the Leppy Hills in comparison to that 

in sections farther to the east and southeast in Utah (for 

example, in the Lakeside Mountains and East Tintic district, fig. 2). In these latter sections, deposits as thick as 

tens of meters that formed during the early phases of the 

Delle phosphatic event are characterized by multiple

Figure 21. Photomicrograph of stylolitized and solution-compacted limestone in the uppermost part of the Joana Limestone. 

Section A, upper A-l Canyon, northeastern Nevada. Location of 

section is shown in figure 3. Bar scale, 0.5 mm.

/ 'fcsflbSSzSLrfr*-* *ii.~. J&T^ -Xk ^-»*Si

Figure 22. Contact between the Joana Limestone and overlying 

Needle Siltstone Member of the Chainman Shale. Section A, upper 

A-l Canyon, northeastern Nevada. Location of section is shown in 

figure 3. Pencil in lower center of photograph points to the contact 

between replacement chert and underlying solution-compacted 

Joana Limestone; pencil in upper center points to the thin layer of 

phosphate pellets atop the chert; and hammer point is resting on 

small outcrop of dolomitic siltstone of the Needle Siltstone 

Member.

layers of peloidal and other forms of phosphate, dissolution and chert replacement of limestone intercalated in 

dolomitic siltstone and phosphatic mudstone, preservation 

of pelagic fossils such as radiolarians in replacement-chert
UPPER DEVONIAN TO MISSISSIPPIAN STRATA, LEPPY HILLS G13

beds and dissolution remnants of limestone, and deposition of other distinctive limestone units indicative of 

peculiar water chemistry (Nichols and Silberling, 1990). 

The Delle phosphatic event has been attributed by us (Silberling and Nichols, 1991) to restriction of the inner shelf 

by the development of a sill in the form of a foreland 

bulge in response to tectonic loading of the outboard continental margin during a late stage of Antler orogenesis. 

The Lower and Upper Mississippian rocks of the Leppy 

Hills may document deposition on the continentward flank 

of this hypothetical foreland bulge and the effects of subtle uplift in the forebulge area contemporaneous with relative depression of the broad, generally flat region farther 

to the east and south. The Gardison Limestone and the 

laterally equivalent upper part of the type Joana Limestone 

were deposited across this region to the east and south of 

the Leppy Hills during the early part of Osagean time but 

were onlapped by the Needle Siltstone Member and its lateral equivalents toward the positive area on which the 

Needle of the Leppy Hills was deposited. The Joana 

Limestone of the Leppy Hills, belonging to an earlier 

sequence cycle, originally may have been significantly 

thicker prior to being eroded below the sequence cycle 

that regionally includes the Gardison, the upper part of the 

Joana, and fine-grained clastic rocks of the Delle phosphatic event such as the Needle Siltstone Member of the 

Chainman Shale.

REFERENCES CITED

Bacon, C.S., 1948, Geology of the Confusion Range, west-central 

Utah: Geological Society of America Bulletin, v. 59, 

p. 1027-1052.

Newman, G.J., 1980, Conodonts and biostratigraphy of the Lower 

Mississippian in western Utah and eastern Nevada: Brigham 

Young University Geology Studies 27, p. 103-121.

Nichols, K.M., and Silberling, N.J., 1990, Delle Phosphatic Member An anomalous phosphatic interval in the Mississippian 

(Osagean-Meramecian) shelfal sequence of central Utah: Geology, v. 18, p. 46-49.

Ogden, L.M., 1951, Mississippian and Pennsylvanian stratigraphy, 

Confusion Range, west-central Utah: American Association 

Petroleum Geologists Bulletin, v. 35, p. 62-82.

Poole, F.G., 1974, Flysch deposits of the Antler foreland basin, 

western United States, in Dickinson, W.R., ed., Tectonics and 

sedimentation: Society of Economic Paleontologists and Mineralogists Special Publication 22, p. 58-82.

Poole, F.G., and Sandberg, C.A., 1991, Mississippian paleogeography and conodont biostratigraphy of the western United States, 

in Cooper, ID., and Stevens, C.H., eds., Paleozoic paleogeography of the western United States-II: Society of Economic 

Paleontologists and Mineralogists, Pacific Section, v. 67, 

p. 107-136.

Sandberg, C.A., and Gutschick, R.C., 1984, Distribution, microfauna, and source-rock potential of Mississippian Delle Phosphatic Member of Woodman Formation and equivalents, Utah and 

adjacent states, in Woodward, Jane, Meissner, F.F., and Clayton, J.L., eds., Hydrocarbon source rocks of the greater Rocky 

Mountain region: Rocky Mountain Association of Geologists, 

p. 135-178.

Sandberg, C. A., Poole, F.G., and Johnson, J.G., 1989, Upper Devonian of the western United States, in McMillan, N.J., Embry, 

A.F., and Glass, D.J., eds., Devonian of the world: Canadian 

Society of Petroleum Geologists Memoir 14, v. 1, Regional 

Syntheses, p. 183-220.

Schneyer, J.D., 1984, Structural and stratigraphic complexities 

within an extensional terrain Examples from the Leppy Hills 

area, southern Silver Island Mountains, near Wendover, Utah, 

in Kerns, G.J., and Kerns, R.L., eds., Geology of northwest 

Utah, southern Idaho and northeast Nevada: Utah Geological 

Association Publication 13, p. 93-116.

 1990, Geologic map of the Leppy Peak quadrangle and adjacent area, Elko County, Nevada, and Tooele County, Utah: 

U.S. Geological Survey Miscellaneous Investigations Series 

Map 1-1938, scale 1:24,000.

Silberling, N.J., and Nichols, K.M., 1990, Tectonic implications of 

wide-spread anoxia on the Mississippian shelf, western and 

northern Utah: Geological Society of America Abstracts with 

Programs, v. 22, p. 83-84.

 1991, Petrology and regional significance of the Mississippian Delle Phosphatic Member, Lakeside Mountains, northwestern Utah, i/i Cooper, J.D., and Stevens, C.H., eds., 

Paleozoic paleogeography of the western United States-II: Society of Economic Paleontologists and Mineralogists, Pacific 

Section, v. 67, p. 425-438.

 1992, Depositional cycles of the Upper Devonian-Lower 

Mississippian limestone succession in the southern Lakeside 

Mountains, in Wilson, J.R., ed., Field guide to geologic excursions in Utah and adjacent areas of Nevada, Idaho, and Wyoming: Utah Geological Survey Miscellaneous Publication 

92-3, p. 131-145.

Published in the Central Region, Denver, Colorado 

Manuscript approved for publication March 22, 1993 

Edited by Judith Stoeser

Graphics prepared by Gayle Dumonceaux and Norma Macs 

Type composed by Shelly A. Fields

AU.S. GOVERNMENT PRINTING OFFICE: 1993-774-049/66064



SELECTED SERIES OF U.S. GEOLOGICAL SURVEY PUBLICATIONS

Periodicals

Earthquakes & Volcanoes (issued bimonthly). 

Preliminary Determination of Epicenters (issued monthly).

Technical Books and Reports

Professional Papers are mainly comprehensive scientific reports 

of wide and lasting interest and importance to professional scientists and 

engineers. Included are reports on the results of resource studies and of 

topographic, hydrologic, and geologic investigations. They also include 

collections of related papers addressing different aspects of a single scientific topic.

Bulletins contain significant data and interpretations that are of 

lasting scientific interest but are generally more limited in scope or geographic coverage than Professional Papers. They include the results of 

resource studies and of geologic and topographic investigations; as well 

as collections of short papers related to a specific topic.

Water-Supply Papers are comprehensive reports that present significant interpretive results of hydrologic investigations of wide interest 

to professional geologists, hydrologists, and engineers. The series covers 

investigations in all phases of hydrology, including hydrology, availability of water, quality of water, and use of water.

Circulars present administrative information or important scientific information of wide popular interest in a format designed for distribution at no cost to the public. Information is usually of short-term interest.

Water-Resources Investigations Reports are papers of an interpretive nature made available to the public outside the formal USGS publications series. Copies are reproduced on request unlike formal USGS 

publications, and they are also available for public inspection at depositories indicated in USGS catalogs.

Open-File Reports include unpublished manuscript reports, maps, 

and other material that are made available for public consultation at depositories. They are a nonpermanent form of publication that maybe cited in other publications as sources of information.

Maps

Geologic Quadrangle Maps are multicolor geologic maps on topographic bases in 7 1/2- or 15-minute quadrangle formats (scales mainly 1:24,000 or 1:62,500) showing bedrock, surficial, or engineering 

geology. Maps generally include brief texts; some maps include structure 

and columnar sections only.

Geophysical Investigations Maps are on topographic or planimetric bases at various scales, they show results of surveys using geophysical techniques, such as gravity, magnetic, seismic, or radioactivity, which 

reflect subsurface structures that are of economic or geologic significance. Many maps include correlations with the geology.

Miscellaneous Investigations Series Maps are on planimetric or 

topographic bases of regular and irregular areas at various scales; they 

present a wide variety of format and subject matter. The series also includes 7 1/2-minute quadrangle photogeologic maps on planimetric 

bases which show geology as interpreted from aerial photographs. The 

series also includes maps of Mars and the Moon.

Coal Investigations Maps are geologic maps on topographic or 

planimetric bases at various scales showing bedrock or surficial geology, 

stratigraphy, and structural relations in certain coal-resource areas.

Oil and Gas Investigations Charts show stratigraphic information for certain oil and gas fields and other areas having petroleum potential.

Miscellaneous Field Studies Maps are multicolor or black-andwhite maps on topographic or planimetric bases on quadrangle or irregular areas at various scales. Pre-1971 maps show bedrock geology in relation to specific mining or mineral-deposit problems; post-1971 maps 

are primarily black-and-white maps on various subjects such as environmental studies or wilderness mineral investigations.

Hydrologic Investigations Atlases are multicolored or black-andwhite maps on topographic or planimetric bases presenting a wide range 

of geohydrologic data of both regular and irregular areas; the principal 

scale is 1:24,000, and regional studies are at 1:250,000 scale or smaller.

Catalogs

Permanent catalogs, as well as some others, giving comprehensive 

listings of U.S. Geological Survey publications are available under the 

conditions indicated below from USGS Map Distribution, Box 25286, 

Building 810, Denver Federal Center, Denver, CO 80225. (See latest 

Price and Availability List.)

"Publications of the Geological Survey, 1879-1%!" may be purchased by mail and over the counter in paperback book form and as a set 

microfiche.

"Publications of the Geological Survey, 1962-1970" may be purchased by mail and over the counter in paperback book form and as a set 

of microfiche.

"Publications of the U.S. Geological Survey, 1971-1981" may be 

purchased by mail and over the counter in paperback book form (two 

volumes, publications listing and index) and as a set of microfiche.

Supplements for 1982, 1983, 1984, 1985, 1986, and for subsequent years since the last permanent catalog may be purchased by mail 

and over the counter in paperback book form.

State catalogs, "List of U.S. Geological Survey Geologic and Water-Supply Reports and Maps For (State)," may be purchased by mail and 

over the counter in paperback booklet form only.

"Price and Availability List of U.S. Geological Survey Publications," issued annually, is available free of charge in paperback booklet 

form only.

Selected copies of a monthly catalog "New Publications of the 

U.S. Geological Survey" is available free of charge by mail or may be 

obtained over the counter in paperback booklet form only. Those wishing 

a free subscription to the monthly catalog "New Publications of the U.S. 

Geological Survey" should write to the U.S. Geological Survey, 582 National Center, Reston, VA 22092.

Note.-Prices of Government publications listed in older catalogs, 

announcements, and publications may be incorrect. Therefore, the prices 

charged may differ from the prices in catalogs, announcements, and publications.