ArticlePDF Available

Lakes, Loess, and Paleosols In the Permian Wellington Formation of Oklahoma, U.S.A.: Implications For Paleoclimate and Paleogeography of the Midcontinent

September 2013
Journal of Sedimentary Research

September 2013

DOI:10.2110/jsr.2013.59

Authors:

Kathleen Benison

West Virginia University

Gerilyn S. Soreghan

University of Oklahoma

Show all 5 authorsHide

Lower to mid-Permian deposits of the Midcontinent (U.S.A.) record a significant and long recognized aridification because they archive the shift from more humid facies (e.g., coal, organic shale) of the Pennsylvanian to widespread redbeds, semiarid to seasonal paleosols (Calcisols, Vertisols), and evaporites by the mid-Permian. The provenance, transport and depositional processes of the voluminous Permian redbeds of the Midcontinent, however, remain largely undefined. The Artinskian Wellington Formation in Oklahoma exhibits high-frequency cycles comprising organic-rich laminated mudstone with thinly laminated (inferred primary) dolomite, variegated laminated mudstone with gypsum, massive, red to gray-green mudstone with pedogenic overprinting, and pale red siltstone. The gypsum exhibits a distinct 87/86Sr isotopic ratio (0.709199) that is inconsistent with Permian seawater. We suggest that these facies record deposition in ephemeral to perennial lakes during a time of increasing aridity and seasonality, the latter indicated by abundant mudcracks, vertic-type paleosols, conchostracans, and lungfish burrows. The fine and uniform grain size and the geochemistry of the siliciclastic component suggest far-travelled and likely eolian transport that ultimately accumulated in both subaqueous and subaerial environments. Provenance analysis indicates the siliciclastic component was sourced chiefly from the southeastern Ouachita– Appalachian orogen and the Ancestral Rocky Mountains (ARM) or its derivative sediment.

.-Summary descriptions and interpretations of the main facies in the Permian Wellington Formation.

…

Leonardian paleogeography of the Midcontinent showing main features mentioned in text. Arrows show general directions of zonal winds (seasonally shifting from southeasterlies to northeasterlies as intertropical convergence zone migrates) and inferred seasonal monsoonal westerlies. Locations of geochemical datasets from other Permian strata used in this study are indicated on map by diagonal lines. Locations and relative sizes of uplifts and basins are based on Berg (1977), McKee and Oriel (1967), Johnson et al. (1989), Algeo and Heckel (2008), and Soreghan et al. (2012).

…

Cumulative probability plot of U-Pb ages of detrital zircons from the outcrop sample of the Midco Member of the Wellington Formation. The curve represents the sum of individual radiometric ages and associated errors of the analyzed zircons. The significance of the age peaks are discussed in the text.

…

Depositional model for the Wellington Formation. Each stage depicted in the diagram is generalized; high-frequency fluctuations likely occurred, creating heterogeneous facies. Perennial-lake stage is represented by the organic mudstone and laminated dolomite. (2) Perennial lake, but with increasing evaporation, causing an overall decrease in water level and formation of the variegated mudstone facies and thicker gypsum and dolomite units, though seasonality and short-term fluctuations allowed occasional return of deposition of organic mudstone. (3) Playa or mudflat stage, during which desiccation features are common and the variegated (or rarely the organic) mudstone was pedogenically overprinted, creating Vertisols. Additional eolian transport of clayey loess coupled with pedogenesis formed the massive mudstones. (4) Loess deposition.

…

Figures - uploaded by Kathleen Benison

Content may be subject to copyright.

Content uploaded by Kathleen Benison

Content may be subject to copyright.

Journal of Sedimentary Research, 2013, v. 83, 825–846

Research Article

DOI: 10.2110/jsr.2013.59

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA, U.S.A.:

IMPLICATIONS FOR PALEOCLIMATE AND PALEOGEOGRAPHY OF THE MIDCONTINENT

JESSICA M. GILES,

MICHAEL J. SOREGHAN,

KATHLEEN C. BENISON,

GERILYN S. SOREGHAN,

AND

STEPHEN T. HASIOTIS

Chesapeake Energy Corporation, Oklahoma City, Oklahoma, U.S.A.

School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma, U.S.A.

Department of Geology and Geography, West Virginia University, Morgantown, West Virginia, U.S.A.

Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A.

BSTRACT

:Lowertomid-PermiandepositsoftheMidcontinent(U.S.A.)recordasignificantandlongrecognized

aridification because they archive the shift from more humid facies (e.g., coal, organic shale) of the Pennsylvanian to

widespread redbeds, semiarid to seasonal paleosols (Calcisols, Vertisols), and evaporites by the mid-Permian. The provenance,

transport and depositional processes of the voluminous Permian redbeds of the Midcontinent, however, remain largely

undefined. The Artinskian Wellington Formation in Oklahoma exhibits high-frequency cycles comprising organic-rich

laminated mudstone with thinly laminated (inferred primary) dolomite, variegated laminated mudstone with gypsum, massive,

red to gray-green mudstone with pedogenic overprinting, and pale red siltstone. The gypsum exhibits a distinct

87/86

Sr isotopic

ratio (0.709199) that is inconsistent with Permian seawater. We suggest that these facies record deposition in ephemeral to

perennial lakes during a time of increasing aridity and seasonality, the latter indicated by abundant mudcracks, vertic-type

paleosols, conchostracans, and lungfish burrows. The fine and uniform grain size and the geochemistry of the siliciclastic

component suggest far-travelled and likely eolian transport that ultimately accumulated in both subaqueous and subaerial

environments. Provenance analysis indicates the siliciclastic component was sourced chiefly from the southeastern Ouachita–

Appalachian orogen and the Ancestral Rocky Mountains (ARM) or its derivative sediment.

INTRODUCTION

The late Paleozoic records Earth’s ‘‘best known’’ pre-Quaternary ice

age characterized by an ‘‘extreme’’ climate (Kutzbach and Gallimore

1989; Crowell 1999; Fielding et al. 2008). Attendant with Pangean

assembly, the equatorial Central Pangean Mountains formed and

atmospheric circulation shifted from zonal to monsoonal, resulting in

cross-equatorial flow and marked seasonality (Kutzbach and Gallimore

1989; Parrish 1993). For reasons that remain debated (Tabor and Poulsen

2008), a significant shift in climate from more humid to arid conditions

occurred in the Permian, especially in western equatorial Pangaea. In

Midcontinent North America, this aridity shift corresponds to the

deposition of the first regionally extensive redbed units by mid-Permian

time. The highly weathered nature of these mudstone and evaporite

outcrops, however, has hindered attempts to constrain the depositional

setting, provenance, and climatic implications (Chaplin 2004).

This study focuses on detailed analysis of a whole core of the

Wellington Formation (Fig. 1A) from northern Oklahoma (Fig. 1B),

with additional observations from a laterally extensive quarried outcrop

(Kay County Quarry) of the same interval. Our objective is to address the

depositional environments, source(s) and transport mechanism(s) of the

siliciclastic sediment and, thereby, paleoclimatic implications of this

regionally extensive unit. Specifically, this study assesses whether 1) the

facies reflect principally continental (lacustrine, loess, and paleosol)

deposition, rather than the previously interpreted marginal marine

environment; and 2) eolian transport was the chief mechanism for the

(volumetrically predominant) siliciclastic component of the Wellington

Formation. These findings bear on improving constraints on regional

paleoclimatic conditions, including atmospheric circulation in this part of

western Pangaea, during a time of major climatic transition in the late

Paleozoic.

GEOLOGIC SETTING AND CONTROVERSIES

The late Paleozoic Gondwanan–Laurasian plate collision produced the

equatorial Central Pangean Mountains (CPM; Scotese et al. 1979; Blakey

2007), expressed in southeastern–mid North America as the Appala-

chian–Ouachita foldbelt (Fig. 2). This collision was roughly coeval with

formation of the intracratonic Ancestral Rocky Mountains (ARM) in

western Pangaea (Fig. 2; Kluth and Coney 1981). Between these tectonic

domains, the Midcontinent region of the U.S. (central Pangaea) generally

formed a low-gradient, low-elevation landscape in nearly equatorial

latitudes (,5uSto,5uN; Tabor et al. 2008) during Pennsylvanian

through Permian time. Superimposed on this low-gradient paleogeogra-

phy was the Amarillo–Wichita uplift and adjacent Anadarko basin and

(northward) Hugoton embayment to the west and southwest and the

Ozark uplift and Ouachita uplifts to the east and southeast (Fig. 2;

McKee and Oriel 1967; Johnson et al. 1989). By Permian time, however,

several uplifts began to subside (De Voto 1980; Gilbert 1992; Sweet and

Soreghan 2010; Soreghan et al. 2012), such that the Amarillo and Wichita

uplifts were covered by lower–middle Permian strata (Johnson 1989; Price

et al. 1996; Gilbert 2002; Soreghan et al. 2012). Similarly, Upper

Pennsylvanian and Permian strata, including the Wellington Formation

in parts of Oklahoma, blanket the Precambrian-cored Nemaha ridge

Published Online: September 2013

2013, SEPM (Society for Sedimentary Geology) 1527-1404/13/083-825/$03.00

(Fig. 2; Luza 1978; Chaplin 1988). This region remained equatorial (,5u

S to ,2uN) from Virgilian (Gzhelian) through Leonardian (Kungarian)

time (Tabor et al. 2008).

Through much of the late Paleozoic, ‘‘icehouse’’ conditions character-

ized by repeated waxing and waning of continental ice sheets (Veevers

and Powell 1987; Crowell 1999; Fielding et al. 2008; Fischbein et al. 2009)

produced pervasive cyclothems at low latitudes (Wanless and Shepard

1936; Heckel 1986; Veevers and Powell 1987). Upper Paleozoic strata of

the Midcontinent record both glacioeustasy and the onset of increasing

aridity (Tabor et al. 2008). From the Pennsylvanian to the mid-late

Permian, deposition in the Midcontinent shifted from limestone–shale

cyclothems of the Chase and Council Grove groups to redbeds and

evaporites of the Nippewalla and El Reno groups (Fig. 1; Johnson et al.

1989; Golonka and Ford 2000; Heckel 2007). The Leonardian

(Artinskian) Sumner Group, including the Wellington Formation

described here, marks the transition between the underlying limestone–

shale cyclothems and the overlying redbeds and evaporites.

The Wellington Formation of the Sumner Group crops out in a narrow

strip from northern Oklahoma into mid-Kansas (Fig. 1B; Mazzullo 1999;

Hall 2004). The Wellington Formation is 250 m (820 ft) thick (Raasch

1946) and encompasses six members; this study focuses on the Anhydrite

sequence and the Otoe and Midco members (Fig. 1A). Gypsum or

anhydrite, siltstone, shale, and mudstone with subordinate dolomudstone

and dolomite constitute the lithology of the Wellington Formation in

Oklahoma (Fig. 3; Raasch 1946; Boardman 1999; Chaplin 2004). The

Wellington and coeval deposits are commonly capped by the coarser-

grained Garber Sandstone (Fig. 1A) in Oklahoma, whereas northward

(Kansas) evaporites, including bedded halite in the Hutchinson Salt

(Fig. 1A; Fig. 2; Swineford and Runnels 1953; Jones 1965; Watney et al.

1988), overlie the Wellington.

Controversy exists over the depositional environment of the Wellington

Formation, with older studies suggesting deposition partly in a lacustrine

setting (Dunbar 1924; Raasch 1946; Tasch 1961a, 1964) and newer studies

postulating marine or marginal marine conditions (Mazzullo 1999;

Chaplin 2004; Hall 2004). Most studies inferring a marine origin for

the Oklahoma strata focused on the dolomite and evaporite facies, owing

to poor outcrop exposures that precluded detailed petrographic

descriptions of other facies. Chaplin (2004) provided general interpreta-

tions of the Wellington Formation based on newly obtained whole core

(including the core used in this study); however, he focused primarily on

the underlying Chase and Council Grove formations of unequivocal

marine origin. For the Wellington Formation, studies favoring a

. 1.—A) Permian stratigraphy of outcrops in north-central Oklahoma, combined and modified from Dunbar et al. (1960), Wilson (1962), Chaplin (1988), and

Johnson et al. (2001). The units and lithology of the Wellington Formation and the Nolans Limestone are shown for Oklahoma and Kansas, based on the work of Ver

Wiebe (1937), Raasch (1946), O’Connor et al. (1968), and Chaplin (1988). The superscripts 1 and 2 in the inset column refer to the specific source that defined the units in

Kansas and Oklahoma. *Stratigraphic names of Wellington and Nolans are members unless otherwise stated, viz. Anhydrite and Basal sequences. B) Study area of Kay

County, Oklahoma depicting the location of the KC-1 core and Kay County Shale Pit outcrop (modified from Chaplin 2004).

826 J.M. GILES ET AL.

JSR

continental origin are based on selected paleontological aspects (e.g.,

insect beds) constrained to certain horizons. Few studies have focused on

the siliciclastic strata, which dominate by volume. Finally, recent fluid-

inclusion and sedimentology work by Benison and Goldstein (2001, 2002)

suggests that the overlying Nippewalla Group in Kansas consists of acid

saline lake deposits amid mudflat, eolian, and paleosol siliciclastic

deposits. A continental origin for even parts of the Wellington Formation

would significantly alter paleogeographic and paleoclimatic reconstruc-

tions and attendant depositional and transport pathways for this time and

region.

METHODS

This study centers on the KC-1 core from Kay County, Oklahoma

(Fig. 1B), drilled by the Oklahoma Geological Survey using freshwater as

the drilling fluid. The cored interval begins at the surface and extends

,91 m, penetrating the upper Anhydrite sequence, the Otoe Member,

and most of the Midco Member of the Wellington Formation, which

crops out at the surface (Fig. 3); thus, the Billings Pool and Antelope

Flats members were not present in the core. We slabbed intervals of the

core and described the entire core at centimeter-scale resolution.

Representative samples of all facies were selected for thin-section and

geochemical analysis. Additionalfaciesdataarebasedonfield

observations of the Wellington Formation exposed in the Kay County

Shale Pit (36u35953.310N, 97u2190.850W) immediately adjacent to the

core site (Chaplin 2004). This quarry exposes the Midco Member of the

Wellington in three dimensions over ,200 m. This aided in more

definitive descriptions of facies contacts and lateral variability of facies.

Four siliciclastic facies and two chemical sediment facies were identified

using macroscopic sedimentologic features supplemented by petrographic

and SEM observations and geochemical and mineralogical characteriza-

tion. Thirty-five thin sections were examined. The core description,

including facies thicknesses and vertical transitions, was used to calculate

facies abundances and determine the most common facies transitions

using a transition-count matrix, an approach similar to Markov-chain

analysis (Carr 1982; Driese and Dott 1984). Five representative samples

were disaggregated using sodium phosphate (Na

)andsonication

for 10 minutes for grain-size analysis. Although grain-size analysis on

lithified rocks can be problematic, the Permian rocks in north central

Oklahoma have not been buried very deeply, ,1km(Carteretal.1998).

The mudstones are poorly indurated, even in core, and petrographic

examination indicates that the facies are poorly cemented, such that the

sonicated sediment provides a reasonable approximation of the original

sediment texture. The measured grain size likely represents a maximum,

in the event any weak cements persisted. Analyses of the disaggregated

sediment after treatment was performed using a Beckman-Coulter LS-230

laser particle size analyzer. In addition, the mass and grain size of the

‘‘acid-insoluble-residue’’ (siliciclastic fraction) was determined from eight

dolomite samples through dissolution in 2N HCL to infer detrital influx

during carbonate deposition. Source-rock-analyzer-based TOC and

pyrolysis data were collected on 10 dark mudstone samples by Weath-

erford Laboratories.

. 2.—Leonardian paleogeography of the Midcontinent showing main features mentioned in text. Arrows show general directions of zonal winds (seasonally shifting

from southeasterlies to northeasterlies as intertropical convergence zone migrates) and inferred seasonal monsoonal westerlies. Locations of geochemical datasets from

other Permian strata used in this study are indicated on map by diagonal lines. Locations and relative sizes of uplifts and basins are based on Berg (1977), McKee and

Oriel (1967), Johnson et al. (1989), Algeo and Heckel (2008), and Soreghan et al. (2012).

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 827

JSR

. 3.—Stratigraphic column of the Wellington Formation in the KC-1 core illustrating facies, inferred water level, and the boundary of the members encompassed by

the cored interval.

828 J.M. GILES ET AL.

JSR

ABLE

1.— Summary descriptions and interpretations of the main facies in the Permian Wellington Formation.

Facies Grain Size Lithology Color Features Mineralogy Environmental Interpretation

Siliciclastic

Facies

Siltstone

Lithofacies

fine silt 10

(st dev 5.6)

Siltstone Light brown to

pale orange

Massive to faintly

laminated or chaotic

bedding +/2patchy

fabric, rare root traces

Primarily subangular

to angular quartz;

rutile, muscovite,

zircon, chlorite, K-

feldspar, and pyrite

Subaerial (eolian)

suspension deposition;

overprinting by

pedogenesis, disruption

by salt crusts

Shallowing-

upward ‘‘cycle’’

Massive

Mudstone

Lithofacies

Red massive

mudstone

very fine silt

to clay

(st dev 5.2)

Mudstone;

gypsum

Dark red to

purple

Massive bedding +/2

slickensides & laminae

of gypsum; local

ped-like structures

Primarily clay (illite

and smectite)

subangular to

angular quartz;

chlorite, rutile,

K-feldspar

Both subaerial (eolian

and minor unconfined

flow deposits) and

subaqueous suspension

deposition. Extensive

pedogenesis.

Gray massive

mudstone

very fine silt

to clay

(st dev 5.2)

Lt gray and/or

greenish or

bluish gray

Primarily clay (illite

and smectite)

angular quartz,

muscovite; quartz,

chlorite, rutile,

muscovite, and

biotite

Laminated

Mudstone

Lithofacies

Variegated

mudstone

clay 3

(st dev 5.3)

Mudstone;

dolomite;

gypsum

Variable and

mixed: red, grey,

yellow, brown,

white

Laminated (mm-scale)

to wavy or chaotic

bedding with evaporite

and dolomite

laminae +/2small

slickensides, mudcracks,

burrows, root traces,

brecciated fabrics, rare

conchocostracans, rare

cubic casts

Primarily clay (illite

and smectite) some

angular quartz

grains; albite, iron

oxides, quartz,

muscovite, chlorite,

and pyrite

Low-energy, subaqueous

suspension settling into

perennial lake, likely

shallow, some

desiccation and

pedogenesis

Organic-rich

mudstone

very fine silt

to clay

(st dev 5.2)

Mudstone;

dolomite

Lt gray - black;

some yellow

and/or green

Laminated (mm-scale)

dolomite and dark

mudstone

Mudstone: Primarily

clay (illite and

smectite) Few

angular quartz grains;

muscovite and

pyrite. Dolomitic

micrite

Low-energy subaqueous

suspension settling in

perennial-lake

environment. Likely

deeper with less

evidence for

desiccation

Chemical

Facies

Dolomite

Lithofacies

n/a ,1–5

m Dolomite;

Ca/Mg 5,1–

1.2; ,25%

siliciclastics

White - buff Laminated (mm-scale)

or thicker beds +/2

desiccation cracks, rare

burrows,

microcrystalline texture,

fenestral fabric

Accessory

mineralogy 5

zircon, quartz,

K-feldspar, albite,

chlorite, iron oxides,

celestite, barite,

pyrite

Low-energy subaqueous

perennial-lake

environment.

Gypsum

Lithofacies

n/a n/a Gypsum;

relatively pure

Clear, white, or

stained red

Laminated (small-scale)

or thicker beds

intermixed with

mudstone +/2vertically

oriented crystals +/2

displacive crystals in

mudstone.

Gypsum and/or

anhydrite

Subaqueous deposition

(bottom growth and

laminated habits) to

penecontemporaneous

formation (displacive

habits); High-salinity

water

______________________

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 829

JSR

830 J.M. GILES ET AL.

JSR

Qualitative phase identification on representative samples from each

facies was accomplished by backscattered electron imaging coupled with

energy-dispersive X-ray analysis (EDXA) using 20 kV accelerating

voltage and 10 nA beam current (see details in Pack 2010). In addition,

35 samples from siliciclastic facies throughout the core were powdered,

processed to eliminate carbonate-bound Ca (following Soreghan and

Soreghan 2007), and analyzed for major and trace elements using

combined XRF and ICP-MS. Finally, a Rigaku automated wide-angle X-

ray diffractometer (XRD) with a graphite monochromator and copper

tube (CuK, 40 kV, 30 mV) was used to characterize clay mineralogy; runs

were conducted between 4 and 70u2hwith step size of 0.05u2hand 5 s

dwell time. Oriented aggregate mounts for XRD were prepared following

Poppe et al. (2002).

For detrital-zircon geochronological analysis, we used a siltstone

sample from the middle of the Midco Member of the Wellington collected

from the quarry outcrop (to obtain sufficient sample from a specific

stratum). For analysis, 2 kg of the siltstone was processed using standard

crushing and heavy-mineral separation techniques (Gehrels et al. 2008).

The analytical procedures in employing the Micromass Isoprobe at the

University of Arizona closely followed those described in detail by

Dickinson and Gehrels (2008) except that a spot diameter of 25

mwas

utilized because of the fine grain size of the zircon. A crystal of the Sri

Lankan zircon (564 64Ma(2herror)) was analyzed for calibration

every five unknowns. The interpreted age for grains ,1 Ga are taken

from

206

Pb/

238

Uageswhereasgrains.1 Ga are based on

206

Pb/

207

ages; these ages are summarized in Appendix 1 (see Acknowledgments).

Age uncertainties are reported at the 1-sigma level and include only

measurement or analytical errors. Ages were analyzed for discordance by

comparing the

206

Pb/

207

Pb ages to the

206

Pb/

238

Uagesforthosegrains

.1 Ga; a 30% difference was used to filter the data. In total, 79 grains

were retained for analysis, and the data are presented as a cumulative

probability plot in which the age and associated errors of each grain are

summed.

For strontium isotope analyses, gypsum samples were selected

representing pristine (unrecrystallized) examples of the various morphol-

ogies present (laminated, displacive, and bottom-growth crystals).

External surfaces were cleaned and the gypsum was powdered using a

drill equipped with an ultra-fine bit. Approximately 2 mg of each sample

powder was placed in 4 ml of quartz-distilled water for 1 week until no

visible sample remained. Subsequently, 0.8 ml of Seastar 14 molar NHO

was added to each vial, to make the solution approximately 3 N HNO

The samples were slowly pumped through 50 microliter Sr spec columns

equilibrated with 3 N HNO

. Approximately 1 ml more 3 N HNO

was

used to wash the other ions from the columns. The Sr was eluted with 2 ml

of quartz-distilled water and dried on a hotplate with 1 drop of dilute

phosphoric acid. The samples were loaded on Re center filaments with a

Ta activator and run at approximately 1400uCinmulti-dynamicmodeon

aIsotopXPhoeniX64.Asmallcorrectionof0.000006wasappliedtoeach

sample to account for the slight difference between the measured value of

NBS987 and the recommended value of 0.710248.

RESULTS

Results are presented in two parts: 1) description and interpretation of

facies comprising the KC-1 core (summarized in Table 1), supplemented

with outcrop observations; 2) geochemical and detrital-zircon geochro-

nologic characterization of the Wellington siliciclastic facies for inferring

provenance.

Facies Analysis

Dolomite

Description.—The dolomite mudstone facies is very fine grained (clay to

very fine silt), white to light gray, and occurs as (1) microlaminae

intercalated with siliciclastic facies (Fig. 4A1, Fig. 5A), or (2) thicker (4 to

48 cm, average 17 cm), structureless to vaguely laminated beds (Fig. 4A2)

that compose 2% of the core. Insoluble residue of the dolomite mudstone

averages 25.2% (n55), and consists predominantly of quartz, potassium

feldspar, iron oxides, and pyrite. Microprobe images reveal aggregates of

rhombohedral dolomite crystals (,1–5

m) with a Ca/Mg ratio of ,1–

1.2. Secondary minerals include pyrite and Fe oxides in addition to trace

amounts of various silicate minerals. Common thin vertical cracks and/or

rare infilled vertical structures occur (Fig. 4B). Gypsum locally occurs as

thin interbeds in the dolomite (Fig. 4B). In outcrop, the dolomite is laterally

continuous (Fig. 6A), with sharp upper and lower bases (Fig. 6B, C).

Interpretation.—The dolomite is interpreted as primary, because it (1)

occurs as discrete beds, particularly as laminae interlayered with

siliciclastic mudstone, (2) displays a very fine-grained (micritic) texture

(Last 1990), and (3) lacks any petrographic evidence for replacement

textures or dolomitization of biogenic calcite or aragonite (Garcia del

Cura et al. 2001). Primary dolomite is typically microcrystalline and

characterized by a fine (less than about 10

m) grain size (Folk 1973; von

der Borch 1976; Vasconcelos and McKenzie 1997). Dolomite with a

larger grain size and a saccharoidal texture is commonly secondary and

displays evidence of replacement (von der Borch 1976). Primary dolomite

of lacustrine origin is typically very fine grained (,1–2

m) and forms

aggregates (Last 1990), like the Wellington dolomite. The coexistence of

iron oxides and pyrite in the dolomite and associated laminated facies is

consistent with dolomite formation from metabolic activity of bacteria

(Trudinger et al. 1985; Last 1990; Machel 2004; Sanz-Montero et al.

2009). In low temperatures and anoxic conditions, bacterial sulfate

reduction is the main process that produces pyrite (Trudinger et al. 1985;

Williams-Stroud 1994; Machel 2004). During bacterial sulfate reduction,

metabolic CO

and bicarbonate ions are released, providing ideal

conditions for carbonate formation in general (Sanz-Montero et al.

2009) and primary dolomite in particular (Vasconcelos and McKenzie

1997; Sanchez-Roman et al. 2008, 2009).

The intercalation of millimeter- to submillimeter-scale laminae of

dolomite and siliciclastic material suggests subaqueous suspension

deposition into a quiet-water environment. There are no indications of

flaser, ripple, or any other type of stratification indicative of traction

processes, and individual beds are laterally continuous across the quarry

face. There are, however, indications of exposure or shallow, subaqueous

conditions superimposed on the dolomite mudstone facies. For example,

we interpret the very fine vertical cracks (Fig. 4A2) as mudcracks,

indicating that exposure and periodic wetting and drying occurred after

the dolomite laminae formed. The larger infilled vertical structures

(Fig. 4B) are likely vertical burrows that suggest oxic (shallower-water)

conditions existed subsequent to dolomite formation.

.4.—CharacteristicsedimentaryfeaturesofvariousfaciesintheWellingtoncore.A1) ,1-mm-thick dolomite laminae (227.4 ft, 69.3 m; Otoe), and A2) thicker,

bedded dolomite (white or light) ,1.25 cm thick with desiccation cracks (51.0 ft, 15.5 m; Midco). B) Microcrystalline dolomite with evaporite(?) voids, laminations of

gypsum, and a burrow (22.5 ft, 6.9 m; Midco). C) Gypsum with vertical crystal growth. C1) Aswallow-tailgypsumcrystal(248.0ft,75.6m;Otoe);C2) Amuddrapeover

gypsum crystals; both are indicative of subaqueous, primary origin (61.1 ft, 18.6 m; Midco). D) Thin section of vertically growing crystals capped by dissolution surface,

suggesting subaqueous origin (60.0 ft, 18.3 m; Midco). E) Photomicrograph displaying well-sorted angular to subangular quartz grains of siltstone facies (279.3 ft, 85.1 m;

Otoe). F) Mound-shaped structure within the siltstone facies (128.0 ft, 39 m; Otoe).

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 831

JSR

832 J.M. GILES ET AL.

JSR

Pure dolomite of stoichiometric composition has a Ca/Mg ratio of 1;

therefore, the Ca/Mg ratio of the dolomite here suggests a relatively

stoichiometric dolomite (Chilingar 1957; Last 1990; Machel 2004) similar

to modern dolomite in saline lakes, although the stoichiometric

composition of dolomite remains equivocal as the chief means of

distinguishing between marine and lacustrine environments (Last 1990).

Gypsum

Description.—Gypsum occurs in three forms (in order of abundance),

1) thicker beds intercalated with siliciclastic material that display

vertically oriented crystals, 2) laminae in mudstone facies (discussed

below), and 3) displacive nodular gypsum in mudstone. The thicker

gypsum beds compose 3% of the Wellington Group in the core. The

vertically oriented crystals widen upward, originate from a common

plane, and exhibit a sharp contact with the overlying mudstone (Fig. 4C1,

D). The overlying mudstone thickens over depressions and thins over

raised gypsum crystal terminations (Fig. 4C2). The transition to overlying

mudstone typically consists of a layer of gypsum regrowth over a thin

layer of mud or a sharp contact with truncated crystals. Rare nodular

beds of gypsum occur with vague remains of vertically twinned gypsum

rhombs. No replacement textures have been identified in thin-section or

microprobe analysis. Microprobe analysis indicates nearly pure calcium

sulfate, with less than 0.1 wt% other (mostly silicate) phases. Strontium

isotope data (

Sr/

Sr) collected from five gypsum samples, representing

all three occurrences of gypsum and lacking any textural evidence of

replacement, are listed in Table 2. The values range from 0.708688 to

0.709711 and average 0.709199.

Interpretation.—The vertically aligned (swallow-tail) crystals of gyp-

sum record subaqueous bottom precipitation in saline surface water

(Benison et al. 2007). The upward-widening habit of the vertical gypsum

crystals and their origination from a common plane support a primary,

subaqueous origin as bottom-growth crystals (Gibert et al. 2007). The

thickening and thinning of mudstone directly above the vertical gypsum

crystals indicates that subaqueous gypsum precipitation occurred prior to

deposition of the mud, which infilled microtopography (Spencer and

Lowenstein 1990). Sharp contacts with the overlying mudstone that

truncate the tops of the underlying gypsum crystals suggest dissolution

prior to mud deposition.

The displacive gypsum crystals likely reflect penecontemporaneous

formation in the host mud. Similar displacive habits form in the shallow

subsurface in both modern saline lakes and sabkhas (Spencer and

Lowenstein 1990; Benison et al. 2007). Some of the displacive gypsum

beds, however, do appear to have altered from anhydrite to gypsum (or

vice versa), which readily occurs at shallow burial depths (Warren 1989;

Gibert et al. 2007).

The Sr-isotope data from all gypsum morphologies (laminated,

displacive, and bottom growth) are inconsistent with (and significantly

higher than) Permian seawater values reported by Korte et al. (2006),

indicating that the gypsum did not precipitate from waters directly

connected to marine sources. This is discussed in more detail below, but

the data indicate a significant continental source for the Sr, and thus,

strong evidence for a continental origin rather than a supratidal or

sabkha setting for gypsum formation.

Siltstone

Description.—The very fine siltstone facies varies from pale orange to

brown to locally white to light gray, and composes 8% of the core. It

consists of well-sorted, angular to subangular siliciclastic (mostly quartz)

grains (Fig. 4E) of fine silt (10

m); the clay-size fraction ranges from

,19 to 70% (average ,34%). The siltstone facies occurs in massive beds

10 cm to 1.2 m thick, with common soft-sediment deformation and

chaotic bedding (Fig. 4F). Downwardly bifurcating, vertical traces (2 to

5cmlong)occurlocally.Typically,basalcontactsareslightlygradational

with the underlying massive mudstone facies, whereas upper contacts are

typically sharp and capped by the organic or variegated mudstone facies.

Although the siltstone facies is present through the middle and lower

portion of the core, it is absent in the upper ,33 m. In the quarry

outcrop, the siltstone appears massive and highly fractured, and is

laterally continuous, with mottling, peds, and vertical traces along the

upper surface.

Interpretation.—The fine-grained and consistently well-sorted texture

suggests eolian transport for this facies (Pye 1987; Tsoar and Pye 1987).

The very fine grain size reflects longer-term suspension and, therefore,

transport from a relatively distant source (Pye 1987; Smalley et al. 2005).

In addition, massive bedding and gradational contacts are most

consistent with suspension fallout during eolian transport as opposed

to traction deposition (Pye 1987; Johnson 1989). Rare root traces (i.e.,

rhizoliths) and poorly developed pedogenic overprinting (see below)

record exposure and preclude subaqueous deposition. The soft-sediment

deformation in this facies could reflect seismites (Montenat et al. 2007)

whereas the chaotic bedding may be a result of extensive bioturbation

(Smoot and Lowenstein 1991). An alternate method of forming soft-

sediment deformation, chaotic bedding, and patchy fabrics, however, is

through precipitation of efflorescent salt crusts. These salt deposits are

typically very thin, easily dissolved, and rarely preserved (Smoot and

Castens-Seidell 1994). In highly permeable sediment, such as silt, the

growth of efflorescent salt results in mounds ranging from 2 to 4 cm that

deform subjacent structures and create a ‘‘popcorn like’’ texture that can

trap silt in depressions, as seen in both modern saline pans (Smoot and

Castens-Seidell 1994) and Permian saline deposits (Benison and Goldstein

2000, 2001).

Organic Mudstone Facies

Description.—The organic mudstone facies is predominantly dark gray

to greenish black (Fig. 5B, 6B) and composes 23% of the study section.

The average grain size is very fine silt to clay (4

m). Light-colored, thin

laminae of subangular to angular coarse silt quartz grains occur

commonly. Total organic carbon (TOC) values are 0.78–1.09 wt.%,

averaging ,0.92 wt%, and Rock-Eval data indicate immature, type IV

kerogen. Microprobe (Fig. 5A) and cathodoluminescence imaging

indicate (sub-millimeter- to millimeter-scale) planar laminae consisting

of alternating dark-colored calcareous mudstone and light-colored

dolomite, locally convoluted. Muscovite, pyrite, and quartz occur in the

clastic laminae, similar to the mineralogy of the gray massive mudstone.

XRD analysis indicates less quartz compared to the red-colored facies

and a clay-rich matrix, consisting of micas, kaolinite, and chlorite.

. 5.—A) SEM-BSE image of dolomite laminae in organic mudstone facies (dolomite produces brighter reflectance in CL; 219.4 ft, 66.9 m; Otoe). B) Typical laminae

in organic mudstone facies exhibiting color variations of gray, black, and lighter-colored dolomite. Notice possible oil staining (24.9 ft, 7.6 m; Midco). C) Typical

expression of laminae in the variegated mudstone facies. Notice color variation among laminae (144.8 ft, 44.1 m; Otoe). D) Cubic halite casts (11.1 ft, 3.4 m; Midco) in

variegated mudstone facies. E) Wavy to sinuous complex mudcracks in variegated mudstone facies viewed in cross section (239.5 ft, 73.0 m; Otoe). F) Imprints of

conchostracans, sizes range from ,1–5 mm (179.0 ft, 54.6 m; Otoe). G) Photomicrograph showing ‘‘floating’’ quartz grains in clay matrix (153.4 ft, 46.8 m; Otoe) of

massive mudstone facies. H) Slickensides (205 ft, 62.5 m; Otoe) in massive mudstone facies.

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 833

JSR

.6.—OutcropphotosoffaciesinMidcoMember.A) Photo across quarry face illustrating the thin-bedded, continuous nature of the facies and lack of scouring. B)

Organic mudstone facies sharply overlying a thicker dolomite bed. C) Interbedded dolomite and organic mudstone. D) Outcrop of massive mudstone showing gradational

nature at base from underlying variegated mudstone facies. E) Blocky peds and reduction features in the massive mudstone facies.

834 J.M. GILES ET AL.

JSR

Dolomite laminae are abundant in this facies, occurring as either

laminae, beds up to 8 cm thick, or small round clasts (Figs. 5A, B, 6C). In

contrast to the abundant mudcracks in the laminated mudstone facies

(described below), this facies rarely exhibits vertical cracks. Overlying

facies are mainly the laminated mudstone or locally the massive mudstone

or siltstone facies. Basal contacts are typically sharp from the underlying

massive mudstone or siltstone facies or rarely the variegated mudstone.

Interpretation.—The dark color, elevated TOC values, and planar

lamination indicate a low-energy, low-oxygen, subaqueous environment.

Although such conditions are commonly associated with deep water, they

can also occur in shallow basins if salinity gradients are sufficient to

reduce vertical mixing (e.g., Great Salt Lake, Utah; Hardie et al. 1978).

The convolute laminae could reflect seismic activity (Montenat et al.

2007), or perhaps mass-flow processes (Benison and Goldstein 2001),

although the regional, low-relief setting argues against the slopes

necessary for the latter. The alternating high- and low-TOC mudstone

laminae suggest seasonality during deposition (Allen and Collinson 1986),

whereas the dolomite laminae represent increased carbonate input (Last

1990). As noted above, the fine-scale, relatively pure laminae of dolomite

interlaminated with the organic mudstone suggests subaqueous, suspen-

sion settling.

Laminated Mudstone Facies

Description.—Laminated, variegated mudstone is the most common

facies in the core, composing 30% of the section. Individual beds of very

fine silt to clay (3–4

m) laminae average ,50 cm thick. Various colors,

chiefly red with less common orange, white, brown, yellow, and gray

occur, varying among millimeter scale laminae (Fig. 5C). Planar to wavy

laminae at the sub-millimeter to millimeter scale are most common, but

chaotic and/or brecciated intervals also occur. Lamination typically fines

upward and consists of light-colored very fine silt, dolomite, or red or

gray mud; rare laminae of peloids also occur. Dolomite appears in the

form of small-scale (,0.1–6 cm) planar laminae, small rounded clasts, or

disseminated within the mudstone laminae. Gypsum is common in this

facies and occurs as planar beds 1–2 cm thick, or as displacive crystals.

Rare cube-shaped casts occur on bedding planes in the upper 3.5 m of

core (Fig. 5D).

Rare, downwardly bifurcating traces occur in this facies along with thin

vertical cracks (1–3 mm wide), randomly oriented slickensides, and

chaotic bedding (Fig. 5E). Rare imprints of whole branchiopod

crustacean conchostraca (,1–5 mm in diameter; identified by Dr. P.

Murry, Tarleton State University, personal communication, 2010; Dr. R.

Scott, University of Tulsa, personal communication, 2010) occur on

bedding planes (Fig. 5F); these conchostraca are whole and unfragmen-

ted and exhibit well-developed growth lines. Generally, the organic or

(rarely) massive mudstone facies underlies this facies, whereas the massive

mudstone or siltstone facies gradationally overlie this facies.

Interpretation.—The millimeter scale laminae and conchostracans

indicate deposition in a low-energy subaqueous environment (Tasch

1964; Smoot 1993). In the Permian, conchostracans typically lived in

continental environments and tolerated a range of salinities (Tasch 1964;

Swanson and Carlson 2002; Park and Gierlowski-Kordesch 2007; Scott

2010). The taphonomy (unabraded and unfragmented) of these bioclasts

indicates little transport prior to death. Tasch (1961a, 1961b, 1962) and

Swanson and Carlson (2002) noted that conchostracans are common in

the Wellington Formation on bedding planes of dolomite–mudstone

intervals.

The laminae of dolomite are similar in texture and grain size to the

thicker laminated (inferred primary) dolomite. The presence of very fine-

grained, laminated dolomite supports subaqueous deposition of the

laminated mudstone facies. Also, the thin, planar laminae of gypsum with

vertically oriented crystals are likely primary, further supporting a

subaqueous origin. The cubic casts record halite casts (Benison and

Goldstein 2001); the alignment of these cubes along bedding planes

suggests that the halite formed in the water column and settled to the

bottom.

Although the evidence suggests a predominance of subaqueous

deposition, periodic subaerial exposure is indicated by 1) root traces

and slickensides, which reflect pedogenesis (Retallack 1990), and 2)

mudcracks and brecciated fabrics, which further indicate subaerial

exposure. The irregular (wavy) shape of the mudcracks is consistent with

highly saline environments (Hardie et al. 1978), whereas the brecciated

fabric could indicate incipient pedogenesis.

Massive Mudstone Facies

Description.—The massive mudstone facies is variably dark red to

purple or light gray to greenish with reddish to purple hues more common

in the Otoe Member and drab gray colors more common in the younger

Midco Member (Fig. 6D). Regardless of color, all display massive bedding

with well-developed, randomly oriented slickensides and blocky peds

(Fig. 6E), rare laminae of gypsum, local brecciated fabrics, and local,

floating subangular to angular quartz grains within the muddy matrix.

Dark red to pale purple mudstone composes 19% of the core and

generally forms beds about 0.5 m thick. Gray to greenish massive

mudstone forms beds about 35 cm thick on average and composes 16% of

the study section. The massive mudstone is composed of very fine silt to

clay grains (3–4

m) of mica and clay minerals (illite, kaolinite, and

smectite) and rare dolomite. Petrographic observations also reveal a clay-

rich matrix with local outsized silt grains of subangular to angular quartz

(Fig. 5G). XRD data reveals that the grayer mudstone contains less

quartz and a higher percentage of clay minerals than the redder

mudstone.

Vertical, bifurcating traces (centimeter scale) are rare, whereas well-

developed slickensides are abundant (Fig. 5H), and autobrecciated fabric

occurs locally in which the clasts exhibit an angular shape. Planar laminae

of gypsum with vertically oriented crystals, 0.1–2 cm thick, locally occur

in these facies with sharp contacts against the massive mudstone.

Generally, the base of this facies grades upward from underlying

variegated mudstone facies with a transition zone consisting of complex

mudcracks and brecciated fabric whereas it is either sharply overlain by

the organic or variegated mudstone or more gradationally by the siltstone

facies.

ABLE

2.— Strontium isotope data from gypsum beds in the Wellington Formation.

Sample Identifier Gypsum Growth Habit

87/86

Sr (raw)

87/86

Sr (corrected) 2-Sigma Error

Gy26.5 displacive 0.70918 0.709186 0.0004

Gy26.5r displacive 0.7092375 0.7092435 0.00006

197.1b bottom growth 0.709244 0.70925 0.0001

KCl60.1 displacive 0.709094 0.7091 0.00009

Gy92.4 laminated 0.708682 0.708688 0.00008

197.1a bottom growth 0.709705 0.709711 0.00007

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 835

JSR

Interpretation.—The fine-grained and well-sorted texture and massive

bedding is most consistent with eolian deposition (Pye 1987; Tsoar and

Pye 1987). Typical far-traveled eolian ‘‘clayey’’ loess is of mud size and

enriched in mica and clay minerals (Junge 1969; Clemmensen 1979; Pye

1987). Abundant slickensides, ped-like features, and root traces record

pronounced pedogenic overprinting in a subaerial setting. The local

brecciated fabric and its angular texture suggests an in situ autoclastic

origin formed from wetting and drying (Benison and Goldstein 2001)

rather than erosion and traction transport of intraclasts, and no other

evidence of traction currents are present. The vertically aligned crystals in

the gypsum interbeds, however, suggest bottom precipitation from

occasional subaqueous conditions (Vandervoort 1997). This is evidence

for ephemeral saline surface waters.

Paleosols

Description.—Prominent, randomly oriented slickensides, blocky peds,

downwardly bifurcating vertical traces, and homogenized bedding occur

in discrete horizons throughout the core, and although most common to

the massive mudstone facies, are not limited to a single facies, and thus,

are summarized here. The slickensides are very pronounced, forming

shiny, subvertical planes in the mudstone that crosscut the entire core

(Fig. 5H) and are visible in outcrop forming high angles to bedding.

Blocky ped structures are also pervasive in these intervals. Microfabrics

include highly birefringent clay, exhibiting two preferred directions.

Intervals throughout the core exhibiting these features have a sharp upper

boundary and a gradational basal boundary. Rare downwardly

bifurcating traces occur, but gray reduction spots are more common.

XRD analyses indicate illite and smectite as the most prominent clay

minerals.

Interpretation.—The presence of (downwardly bifurcating) root traces,

abundant slickensides, and blocky peds record pedogenesis, specifically

development of Vertisols (Retallack 1990). Slickensides form from

shrinking and swelling of clay, particularly smectite during wetting and

drying (Retallack 1990), and the basal gradational boundary and sharp

upper boundary are consistent with pedogenesis. The structureless

bedding and lack of horizonation reflect pedoturbation as a result of

the shrinking and swelling (cf. Goebel et al. 1989). The oriented

microfabric is defined as clinobimasepic fabric (Retallack 1990) and

commonly occurs in Vertisols due to stress produced from shrinking and

swelling of clays (Nettleton and Sleeman 1985). Pedogenic overprinting is

most common in the massive mudstone facies and, subordinately,

variegated mudstone facies.

Geochemical Analysis

Whole-Rock and Trace-Element Geochemistry.—Whole-rock geochem-

istry of the Wellington provides information on potential provenance of

the sediment and chemical processes during deposition and early

diagenesis. In the following we compare the chemical data to several

reference compositions to ultimately test hypotheses of provenance but

also depositional processes. These reference datasets include: upper

continental crust (UCC; Taylor and McLennan 2001), average shale (SH;

Taylor and McClennan 1985), Quaternary loess (QL; Taylor and

McClennan 1985), upper Paleozoic loessite (UPL; Soreghan and

Soreghan 2007), Colorado Plateau crustal model (CPC; Condie and

Selverstone 1999); Ouachita flysch (OAU; Gleason et al. 1995; Sutton and

Land 1996; Totten et al. 2000), and roughly coeval Permian redbeds from

western Kansas (KA; Cullers 1994). The locations of these regional

datasets are shown in Figure 2.

The SiO

values (Fig. 7A) for the siltstone facies are higher (58 to 88.5

wt.%) and more variable than the mudstone facies (,58 to 60 wt.%); the

siltstone SiO

values are also higher than upper continental crust (UCC),

but similar to upper Paleozoic (UPL) and Quaternary loess (QL) values.

The mudstone facies samples are enriched in Al

compared to the

siltstone facies, UCC, UPL, and QL, but are similar to average shale (SH)

and Ouachita flysch (OAU). The difference in the ratio of SiO

/Al

between the mudstone and siltstone likely reflects grain-size effects rather

than differences in weathering or provenance owing to the higher

concentration of clay minerals in the mudstone (Taylor and McClennan

1985; Cullers 1994).

The crossplot of total alkali metal oxides (Na

O+K

O) vs. SiO

(Fig. 7B) shows a depletion relative to UCC in alkalis and no trend in the

mudstone facies, further reflective of a uniform composition of the

various mudstone facies. The siltstone facies displays a negative trend

(Fig. 7B), with values similar to UPL and QL. The Wellington mudstone

samples are relatively uniform and depleted in Na

O compared to the

siltstone samples when normalized to Al

,whereasthesiltstonefaciesis

more variable (Fig. 7C). The mudstone samples are again more similar to

SH and OUA, while the siltstone samples are more similar to QL, KA,

and UPL in the normalized plot. Na

O and K

O ratios in sediments are

typically controlled by source rock (Garrels and MacKenzie 1971), but

also can reflect weathering either prior to deposition or in situ (McLennan

et al. 1993; Qiao et al. 2009).

Differences in trace-element composition exist among the Wellington

facies. A plot of Th/Sc vs. Cr/Th (Fig. 7D) illustrates that the mudstone

samples uniformly lie between ratios for UCC (Th/Sc 51), which is

enriched in incompatible elements, and more mafic sources (Th/Sc 50.6;

Totten et al. 2000). In contrast, the siltstone samples exhibit a more

variable Th/Sc ratio, typical of a continental signature (Fig. 7D). The

siltstone samples plot similar to KA and UCC, whereas the mudstone

samples plot similar to the SH and OUA values.

Finally, there are a number of other differences in trace-element

composition of the mudstone compared to the reference data (Fig. 7E).

For example, the mudstone facies are enriched in Cr, Ni, and V compared

to UCC but depleted in Sr compared to UCC. The mudstone facies also

exhibits differences in trace-element pattern compared to average shale

(SH; Fig. 7E).

Detrital-Zircon Geochronology.—The Wellington Formation contains

zircons with U-Pb ages that range from Archean in age to ,350 Ma

(Appendix 1; Fig. 8). A large number of zircon grains (n514) fall into a

group that spans early Paleozoic (530–370) ages (Fig. 8). There are a few

grains in the age range of 570–740 Ma; however, the dominant mode are

grains (n531) of mostly Mesoproterozoic age that cluster within the

ranges of 900–1360 Ma. Finally, there is also a population of grains

(n511) that yield ages between 1610 and 1800 Ma and a few scattered

Archean ages (.2500 Ma, n54).

Provenance Interpretations of Geochemistry

The composition of the Wellington sediments differs significantly from

UCC. Multiple cross plots of the geochemistry data of the Wellington

sediments, including Na

O/Al

vs. K

O/Al

, Th vs. Sc, Th/Sc vs. Cr/

Th, and Th/U vs. Th, all show that the composition reflects mixed felsic

and mafic provenance, suggesting derivation from multiple sediment

sources.

The mudstone composition plotted on Na

O/Al

vs. K

O/Al

(Fig. 7C) and Th/Sc vs. Cr/Th (Fig. 7D) empirically suggests the

Ouachita Mountains (OAU) as a possible sediment source. The

composition of the Ancestral Rocky Mountains (ARM) is represented

in this study through derivative sediments, i.e., upper Paleozoic loess

(UPL; proximal) and Kansas shale (KA; distal) and is also similar to

the composition of the Wellington sediments. Overall, both KA, which

represents distal ARM sediment (Cullers 1994), and the Ouachita

836 J.M. GILES ET AL.

JSR

.7.—GeochemicalplotsofWellingtonmudstone(circles)andsiltstone(triangles)comparedtovariousgeochemicalreferencedatasets:UCCuppercontinental

crust; OUA Ouachita-derived sediments; KA Permian shales in Kansas; UPL upper Paleozoic loessite; SH average shale. See text for references. A) Crossplot of Al

vs.

SiO2, B) crossplot of Na

O+K

O vs. SiO

.C) Plot of Na

O/Al

vs. K

O/Al

. Mudstones plot between mafic and felsic compositions. Igneous, sedimentary, and

shale lines are from Garrels and MacKenzie (1971). D) Plot of Th/Sc vs. Cr/Th, with the bold line representing an idealized signature of a mixing line between granite and

MORB (mid-oceanic-ridge basalt) sources. The Wellington mudstone facies plots along the mixing line, while the Wellington siltstone facies trend toward a more felsic

composition. After Totten et al. (2000). E) Spider plot of average trace-element value of mudstone facies compared to various reference datasets.

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 837

JSR

Mountains detritus (OAU) both seem to best fit the relative proportion

of the trace elements in the Wellington mudstones (Fig 7E), particularly

when compared to average shale or upper continental crust. Although

the ARM contains higher silica content than the Ouachita Mountains

flysch, both are composed mainly of felsic-derived rock types (Cullers

1994; Totten et al. 2000) and exhibit similar compositions.

In contrast, the Wellington siltstone facies differs in composition from

the mudstone facies and trends toward a more felsic source. The

Wellington siltstones consistently plot similar to Paleozoic sediments

derived from the ARM, although a few siltstone samples overlap the

mudstone samples. Thus, overall the siltstone geochemistry signals

primary derivation from the ARM or its derivative sediments, with

either some secondary mixing with mudstone during pedogenic over-

printing or periodic sediment input from the Ouachita Mountains.

Another characteristic of the geochemical data is the uniform

composition of the different mudstone facies, which may indicate

sediment derivation from similar, well-mixed, distal source(s). Totten et

al. (2000) interpreted multiple sources for the Pennsylvanian Stanley

Group based on two distinct clusters in plots of Th vs. Sc and Th/Sc vs.

Cr/Th (Fig. 4 and 5 in Totten et al. 2000). In contrast, the Wellington

mudstone samples cluster tightly, typically between compositions of

felsic and mafic source rocks. Similarly, Cullers (1994) inferred a

homogeneous, well-mixed sediment source for distal mudstone deposits

compared to a heterogeneous, less-well-mixed source in more proximal

coeval deposits.

The detrital-zircon ages of the single sample analyzed are consistent

with interpretations of a mixed source. Although forming the most

abundant population, zircons with ages ranging from ,900 to 1300 Ma

(Fig. 8) are a common signature in upper Paleozoic deposits (Dickinson

and Gehrels 2003) that reflect contribution from Grenville basement and

do not necessarily suggest a unique source region for detrital grains in

the Wellington Formation. Grenville basement and derivative sediment

with grains of these ages lies both east (Becker et al. 2005) and south

(Gleason et al. 2007) of the study site. The population of grains in the

1600–1800 Ma range (Fig. 8) likely were derived from the Ancestral

Rocky Mountains or derivative deposits to the west of the study site,

where basement terranes (Yavapai–Mazatzal) of that age were exposed

throughout the Pennsylvanian and earliest Permian (Van Schmus et al.

1993), and zircons of these ages are a common component of slightly

older loessite deposits (M. Soreghan et al. 2002; Soreghan et al. 2008a).

Zircons of mid-Paleozoic age have been reported from terranes in the

Appalachian–Ouachita systems, and particularly terranes of Mexico and

Central America then situated south of the Ouachita system (Weber

et al. 2006; Martens et al. 2010; Soreghan and Soreghan 2013). This

suggests a south-southeast source direction for the mid-Paleozoic

detrital zircons.

DISCUSSION

Depositional Setting for the Wellington Formation

Since the original studies of the Wellington Formation, the deposi-

tional setting of this unit has been debated (Dunbar 1924; Raasch 1946;

Tasch 1964; Schultz 1975; Chaplin 2004; Hall 2004). Virtually all workers

have noted that there is definite evidence for continental deposition, but a

number of workers still favor a marine or marginal marine origin for

most of the Wellington, and attempt to reconcile the mixture of signals by

calling on either a tidal or sabkha environment or invoking numerous

transgressions and regressions at various temporal scales. Our facies,

petrographic, and geochemical data strongly suggest that the Permian

Wellington Formation of north-central Oklahoma formed in continental

environments, including saline and freshwater perennial lakes, playas,

wind-blown silt fields (loess), and soils. There is no diagnostic evidence

for marine or marginally marine paleoenvironments in the Anhydrite

sequence, the Otoe Member, and the Midco Member present in the KC-1

core and nearby outcrop.

The KC-1 core contains numerous paleosols, most of which are

inferred to be Vertisols. Paleosols in the Wellington were also

documented by Raasch (1946) and Hall (2004). Vertisols unequivocally

reflect extensive subaerial exposure and pedogenic overprinting of the

underlying sediment. If this underlying sediment is interpreted as marine,

or even intertidal, however, then superposition of these pedogenic

features necessitates numerous and very abrupt fluctuations in sea level.

For example, in Pennsylvanian cyclothems, paleosols commonly occur at

each cycle top, commonly on the 10 m (100–400 ky) scale in subsiding

cratonal regions (e.g., Heckel 1986; Davydov et al. 2010), whereas

paleosols occur on average every 3–5 m in the Wellington. In a lake basin,

however, abrupt changes of lake level, from relatively deep to dry, can

occur on the order of 10

years or less, even in very large tropical lakes

(e.g., Lake Victoria; Johnson et al. 1996).

Evaporites form in a wide range of environments, including marine,

marginal marine, and continental, which has obfuscated interpretations

of the Wellington Formation. The Sr isotope composition of the

gypsum, however, indicates a continental origin. The

Sr/

Sr compo-

sition of Permian seawater is well characterized and drops through the

early Permian (Korte et al. 2006) from ,0.7080 at the start of the

Permian to ,0.7070 in the Kungurian, then rises to 0.7077–0.7074

during the Artinskian. The data from the Wellington, averaging 0.7092,

indicate a (mainly) continental source. Given that some of the gypsum

records subaqueous formation, the most likely environment is a saline

perennial lake, whereas the gypsum that precipitated displacively likely

reflects a playa environment. We use the terms saline lake to refer to

continental basins with input of both groundwater and surficial water

from continental sources; playa to refer to continental basins with

.8.—CumulativeprobabilityplotofU-Pb

ages of detrital zircons from the outcrop sample

of the Midco Member of the Wellington

Formation. The curve represents the sum of

individual radiometric ages and associated errors

of the analyzed zircons. The significance of the

age peaks are discussed in the text.

838 J.M. GILES ET AL.

JSR

mainly meteoric groundwater input; and sabkha to refer to arid

shorelines with periodic input of surficial marine water (Yechieli and

Wood 2002).

Since the dolomite is intimately associated with the gypsum, then the

setting of the dolomite formation is more consistent with a continental

environment rather than a sabkha or lagoonal setting. Specifically, the

fine grain size and laminated character is consistent with a perennial,

saline lake in which the dolomite formed as a primary precipitate.

Dolomicrite, commonly interlaminated with siliciclastic material, is

common in the geologic record in units interpreted as offshore lake

facies (Desborough 1978; Deckker and Last 1988; Last 1990; Calvo et al.

1999). Indeed, the precipitation of gypsum could be one factor in

elevating the Mg ratio of the solution from which the dolomite ultimately

formed. A perennial-lake origin for the laminated dolomite is also

consistent with its co-occurrence with the organic-rich mudstone facies,

which further suggests low-oxygen, perennial lake conditions.

In addition to those attributes suggestive of a perennial lake, several

intervals in the study section display features more consistent with

periodic exposure in a playa environment, such as common desiccation

features, displacive gypsum, and mudstone displaying disrupted bedding

(autobrecciation and inferred efflorescent crusts; Spencer and Lowenstein

1990; Benison and Goldstein 2001). Although a number of these

sedimentary features are characteristic of a range of environments, their

interbedding with the inferred perennial-lake deposits, and the presence of

interbedded gypsum, with its continental chemical signature, suggests a

playa setting rather than sabkha, supratidal, or lagoonal setting.

The paleontologic evidence from the Wellington suggests a continental

signature for the study area with more brackish conditions to the north in

Kansas. The only fossils observed in the core are conchostracans found

on bedding planes of the laminated mudstone facies, which appear

pristine and in situ.BythePermian,conchostracanswerecommonin

continental environments (Tasch 1964; Swanson and Carlson 2002; Park

and Gierlowski-Kordesch 2007; Scott 2010); however, some conchos-

tracan species, commonly Triassic in age, may indicate brackish

conditions (Kozur and Weems 2010). In outcrops of the Wellington,

the ranges of fossils vary depending on location. Fossils reported in

Oklahoma (Table 3) outcrops indicate more freshwater conditions,

including conchostracans (Tasch 1961; Hall 2004), lungfish burrows

(Carlson 1999; Chaplin 2004), vertebrate ichnofauna (Swanson and

Carlson 2002), occasional stromatolites (Hall 2004), and insect beds

(Beckemeyer and Hall 2007). In contrast, fossils reported in Kansas

outcrops (Table 3) may indicate more brackish to marine conditions,

including eurypterids (Eurypterus sellardsi; Dunbar 1924), horseshoe

crabs (see below; Dunbar 1924; Hall 2004), stromatolites (Carlson 1968;

Hall 2004; Bolhar and Van Kranendonk 2007), Lingula (Dunbar 1924;

Hall 2004), and pelecypods (Dunbar 1924; Hall 2004). Stratigraphically,

the Oklahoma outcrops are reported as younger, including the Midco

through basal Billings Pool members, whereas the slightly older Kansas

outcrops include the upper Annelly Gypsum through the Carlton

Limestone (Midco equivalent) members (Table 3). Therefore, the

paleontology alone suggests that the stratigraphically older Wellington

fossils of Kansas indicate more brackish conditions, while the younger

Wellington fossils of Oklahoma suggest more continental conditions.

Finally, albeit negative evidence, the Wellington strata examined in this

study lack characteristics that generally define a sabkha or tidal

environment. For example, characteristic features such as, e.g., ‘‘chick-

en-wire’’ and enterolithic evaporites (gypsum or anhydrite), widespread

fenestral fabrics, flat-pebble intraclast conglomerates, and tepee struc-

tures (Warren and Kendall 1985) are rare to absent in the study strata. In

addition, sabkha deposits are typically interbedded with shallow subtidal

deposits (Schreiber 1978), whereas the Wellington lacks associated

normal marine deposits. Finally, no evidence occurs for the peritidal

‘‘trinity,’’ i.e., subtidal, intertidal, and supratidal subenvironments

(Warren and Kendall 1985), marked by facies and features such as

peloidal, oolitic, and skeletal grainstone, burrowed carbonate mudstone,

flaser bedding, and ripple cross-stratification.

Transport Processes of Wellington Formation Siliciclastics

The commonly accepted mode of transport for Pennsylvanian–Permian

clastics occurring in Oklahoma is fluvio-deltaic, with ultimate preserva-

tion in environments interpreted to range from fluvial and lacustrine to

deltaic and tidal flat (Twenhofel 1926; Wilson 1927; Fay 1964; Johnson

1990; Mazzullo 1999). These interpretations are based in part on evidence

such as the presence of cross-bedded sandstone, which occurs in the

Garber Sandstone immediately overlying the Wellington Formation

(Raasch 1946; Elrod 1980) and the presence of inferred marine evaporites

in the enclosing formations (Twenhofel 1926; Wilson 1927; Fay 1964;

ABLE

3.—General summary of paleontology found in the Wellington Formation. Note that brackish to marine environmental indicators are most common

in Kansas.

Fossil Type

Location (County)

Member

Interpreted Environment from

Source Source

Oklahoma Kansas

Conchostracans Noble and Kay Sumner, Sedgwick,

Harvey, Marion,

Dickinson

basal Billings Pool Continental Tasch 1964; Swanson and

Carlson 2002; Park and

Gierlowski-Kordesch

2007; Scott 2010; Kay

County Core

Lungfish burrows Noble none reported basal Billings Pool Continental Carlson 1999; Chaplin 2004

Insect beds Noble Dickinson basal Billings Pool (OK);

Carlton Limestone (KS)

Continental Beckemeyer and Hall 2007

Stromatolites Noble and Kay Dickinson basal Midco (OK); basal

Carlton Limestone (KS)

Brackish to Marine Hall 2004

Vertebrate ichonofauna Noble Dickinson basal Billings Pool Continental Swanson and Carlson 2002

Eurypterus sellardsi none reported Dickinson basal Carlton Limestone Brackish to Marine Dunbar 1924; Hall 2004

Horseshoe crabs

(Paleolimnus signatus)

none reported Dickinson basal Carlton Limestone Disagreement between

authors: Continental

or Brackish

Dunbar 1924; Babcock et al.

2000; Hall 2004

Pelecypods none reported Dickinson basal Carlton Limestone Brackish to Marine Dunbar 1924; Hall 2004

Lingula none reported Dickinson Annelly Gypsum/basal

Carlton Limestone

Brackish to Marine Dunbar 1924; Hall 2004

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 839

JSR

Johnson 1990). Some researchers, however, have postulated an eolian

origin for the mudstone in the Wellington and younger Flowerpot

formations (Raasch 1946; Yang 1985; respectively). In the Midco and

Otoe members of the study area, evidence for fluvio-deltaic deposition

does not occur: the siliciclastic strata exhibit a narrow (clay–silt) grain size

and lack evidence for erosional scouring or any channels. Cross-bedding

does occur in the Billings Pool Member in outcrop (above the study

interval) and oscillation ripple marks have been identified in thin

siltstones in the Midco Member (Hall 2004), yet the predominant

stratification type in the clastic facies is either laminated or massive.

The predominant facies in the Midco and Otoe members, the laminated

mudstone facies, reflects subaqueous deposition as indicated by very

continuous laminae and interlaminated dolomite and bottom-growth

gypsum. If the siliciclastic mud discharged as a strong overflow current

(hypopycnal flow) from one or more point sources in a density-stratified

lake the sediment would spread horizontally and ultimately sink as a

suspension deposit (e.g., Lake Turkana, Cohen 1989). This requires

considerable depth of the lake body to create the density gradient

required to buoy the sediment plume. The laminated mudstone facies,

however, contains numerous horizons of mudcracks, suggesting numer-

ous desiccation events. Thus, if the mud laminae were deposited as a

result of a series of overflow discharge events, then large-magnitude lake-

level fluctuations must have also been very abrupt and very common. If,

conversely, the mud discharged into the lake as a strong underflow

current (hyperpycnal flow) from one or more point sources, then distinct

sedimentary features should occur, e.g., laminae that exhibit grading, and

association with silty and at least fine sandy beds (Soyinka and Slatt

2008), which are absent.

A third possibility is that the clastic sediment was introduced into the

lake system via eolian processes. In the study section, grain-size averages

are in the very fine- to fine-silt range, typical for distal eolian dust (Pye

1987; Smalley et al. 2005), and dust deposition in lakes and playas is a

common phenomenon, particularly downwind of arid to semiarid regions

(e.g., southwestern U.S., Reheis et al. 1995; Lake Biwa, Xiao et al. 1999;

Lake Chad, Evans et al. 2004; man-made Lake Volta, Breuning-Madsen

and Awadzi 2005; northwest China, Qiang et al. 2007; Dead Sea, Haliva-

Cohen et al. 2012). In most of these modern systems, the eolian

component is of very fine silt to clay size and occurs as laminae in the lake

sediment or in more massive beds disturbed by biogenic reworking. Dust

transport and settling into a shallow, saline lake subject to occasional

desiccation, would produce mudcracked surfaces. Taking into consider-

ation the bulk of the evidence, including the lack of channels or sediment

thickening and coarsening indicative of point-source inputs of the

siliciclastic component to the lacustrine system, we favor eolian transport

as the chief mechanism of delivery of siliciclastic grains to the

depositional site. This process resulted in formation of the laminated

mudstone facies through subsequent suspension settling of the sediment

in a perennial lake that experienced periodic desiccation that formed the

millimeter scale laminae and mudcracks, respectively.

As noted above, the massive mudstone facies is also interpreted as

eolian in origin. The similar texture of the laminated and massive

mudstone, transitional contacts, and lack of erosional scours or lag

features between the facies suggest a similar transport mechanism. The

massive character and association with Vertisols could be interpreted to

reflect unconfined flow in which mud aggregates were carried in traction

(Wright and Marriott 2007). The massive mudstones in this case,

however, lack almost all of the common macroscopic attributes of such

traction-flow deposits as defined by Wright and Marriott, such as 1)

erosional bases, 2) intraclast lenses or lags, 3) related facies associations

(e.g., conglomeratic lenses, pedogenic carbonates), and 4) lenticular

stratification of interbedded calcrete clasts. Thus, we favor a mainly

eolian transport interpretation, in which the mud settled onto a playa or

shallow lake system, and was subsequently further homogenized

pedogenically. This still allows the possibility of occasional unconfined

flow events associated with storms to remobilize and locally transport

previously deposited mud (Alonso-Zarza et al. 2009). This also does not

eliminate the presence of aggregates, and the microscopic observation of

quartz clasts floating in mud matrix (Fig. 5G) suggests that aggregates

might have existed. However, we suggest that if the mud did form

aggregates, these were transported via eolian processes and might be

similar to Quaternary eolian deposits documented in Australia (parna).

Butler (1956) suggested that these massive, clayey, pedogenically altered

deposits (1–3 m thick) were formed by wind transport of silt-size clasts of

clay aggregates, although this process remains obscure (Hesse and

McTainsh 2003).

Finally, the siltstone facies are interpreted as loess(ite) deposits that

accumulated over the playa system during phases when no standing water

occurred. The massive texture, well-sorted silt grain size, and provenance

are all consistent with an eolian origin, and no features occur consistent

with traction flow, whether confined or unconfined (e.g., lateral-accretion

surfaces, or planar or ripple cross lamination). The provenance, reflected

in both the geochemical and detrital zircon attributes, indicates a mixed

source that reflects regions both east and west of the study area,

consistent with a seasonally changing wind regime.

Wellington Lake Model and Regional Paleoclimatic Implications

The climate-sensitive sediments composing arid, closed-basin lakes

record high-frequency variations in regional short-term climates and are

useful for paleoclimate interpretations (Smith et al. 1983; Olsen 1986;

Smith and Bischoff 1997; Lowenstein et al. 1999; Lowenstein et al.

2003). No evidence exists for major changes in tectonic regime during

deposition of the Wellington Formation; thus, deposition was chiefly

influenced by regional climate changes and should be considered an

‘‘optimal’’ reflection of paleoclimate (Smith and Bischoff 1997; Low-

enstein et al. 2003). The facies in the Wellington Formation appear to

reflect at least two different temporal scales of climate change. First, the

facies stacking suggest repeated, upwardly shallowing events (detailed

below). Second, a more detailed examination of the facies transitions

suggests that, in the upwardly shallowing successions, small-scale

fluctuations indicative of higher-frequency wetting and drying occurred,

evinced by juxtaposition and overprinting of facies and features,

including: 1), the syncopated pattern of facies, for example the organic

and laminated mudstone facies; 2) specific features, such as Vertisols

containing slickensides; 3) alternating laminae of evaporites (dry) and

clastics (wet); and 4) complex mudcracks reflecting seasonality. In

addition, the presence of conchostracans indicates seasonality, as their

eggs are laid in ephemeral water bodies (Tasch 1958; Swanson and

Carlson 2002); similarly, lungfish, reported from the Wellington,

aestivate in burrows during dry episodes (Carlson 1968; Hasiotis et al.

1993; Swanson and Carlson 2002).

Vertical facies transitions in the study section indicate a preferred

vertical stacking pattern of, from base to top: (1) organic mudstone with

dolomite, (2) laminated mudstone with gypsum, (3) dark red or gray

massive mudstone, and (4) fine-grained siltstone. Using the organic

mudstone as a base for each, the study interval records at least 30

deepening and subsequent shallowing episodes (Fig. 3) that likely reflect

longer-term climatic change during Wellington Formation deposition.

Perennial Freshwater Lake Stage.—This stage represents the ‘‘flooding

stage’’ and the most humid interval as groundwater, direct precipitation,

and related runoff filled the basin and deposited the organic mudstone

facies (Fig. 9). It is typical in tropical lake systems that direct

precipitation and evaporation dominate the local hydrology, for example,

even in modern Lake Tanganyika, the second largest freshwater lake in

the world by volume, the main contribution to water input is direct

840 J.M. GILES ET AL.

JSR

. 9.—Depositional model for the Welling-

ton Formation. Each stage depicted in the

diagram is generalized; high-frequency fluctua-

tions likely occurred, creating heterogeneous

facies. Perennial-lake stage is represented by the

organic mudstone and laminated dolomite. (2)

Perennial lake, but with increasing evaporation,

causing an overall decrease in water level and

formation of the variegated mudstone facies and

thicker gypsum and dolomite units, though

seasonality and short-term fluctuations allowed

occasional return of deposition of organic

mudstone. (3) Playa or mudflat stage, during

which desiccation features are common and the

variegated (or rarely the organic) mudstone was

pedogenically overprinted, creating Vertisols.

Additional eolian transport of clayey loess

coupled with pedogenesis formed the massive

mudstones. (4) Loess deposition.

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 841

JSR

precipitation (Nicholson 1999). This stage represents in aggregate ,25%

(by thickness) of the study interval, and thus, a significant part of the

paleogeography. The lake was likely stratified and possibly anoxic,

enhancing sulfate reduction and dolomite formation, and preservation of

laminations and organics (Trudinger et al. 1985; Last 1990; Machel 2004;

Sanz-Montero et al. 2009). Seasonality or short-term changes in

hydrology likely caused fluctuations in salinity and water level as

evidenced by variable thicknesses of dolomite deposits, some with

desiccation features, and rare gypsum laminations in the organic

mudstone facies. Rare periods of increased salinity and evaporation

would trigger subaqueous gypsum growth on the lake bottom and within

the sediment, analogous to other examples of evaporites forming

contemporaneously with high rates of organic deposition along a lateral

salinity gradient (e.g., Nury and Schreiber 1997). Arid episodes may have

also resulted in eolian transport of silt-size clastics into the lake, creating

rare organic-poor (lighter-colored) silty laminae.

Perennial Saline Lake Stage.—This stage represents increasing aridity

leading to greater evaporation rates and higher salinity, and consequent

deposition of the laminated variegated mudstone (Fig. 9). Although this

stage represents a shallower, less anoxic lake, evidence for strong

seasonality and a fluctuating water chemistry includes: 1) local dolomite

laminations, 2) abundant desiccation features, including complex

mudcracks penetrating throughout each mudstone bed and at the top

of the interbedded dolomite beds, 3) small pedogenic slickensides, 4)

brecciated layers and chaotic bedding thinly interbedded between

laminated intervals, and 5) variegated colors (Chaplin 2004). Pulses of

eolian silt and clay entered the lake and formed the discrete silty

laminations. Most of the gypsum in the core formed during this stage,

with both subaqueous vertical crystal precipitates and intra-sediment

precipitates. The presence of both of these forms of gypsum vertically

juxtaposed further indicates abrupt fluctuations in water level (Benison

and Goldstein 2001). Conchostracans occur during this stage and were

able to tolerate the high-stress environment of a saline lake (Tasch 1961a),

but they occur in beds lacking evaporites and thus probably represent

periods of slightly decreased salinity.

Ephemeral (Playa) Stage.—During this stage, much of the water

covering the basin evaporated, exposing the laminated variegated

mudstone (Fig. 9). Transitional contacts between the variegated mudstone

and overlying massive mudstone (Vertisols) facies support a similar (initial

eolian) origin for these clastics, with the massive mudstone reflecting both

ultimate deposition as loess, rather than subaqueous settling, and

pedogenic overprinting. Several authors suggest that the exposed surfaces

in saline lake environments experience almost constant pedogenic

overprinting (Bowler 1986; Smoot and Lowenstein 1991; Gierlowski-

Kordesch and Rust 1994). Seasonal wetting and drying of mudstones

during pedogenesis led to development of Vertisols. The geochemical

similarity between the massive and laminated mudstones lends additional

evidence for the genetic relationship between these two facies.

Loessitic Stage.—The final stage is represented by eolian deposition of

the siltstone facies, reflecting the most prolonged arid phases (Fig. 9).

Rare pedogenic overprinting in the siltstone (indicated by root traces)

may reflect periods of decreased sediment influx. Trapping of loess

requires moist ground and thus, seasonal wetness (Pye 1987). As saline

groundwater evaporated from these silt deposits, efflorescent salts

formed, resulting in the patchy fabric, and chaotic bedding, analogous

to modern examples in Saline Valley and Death Valley (Gierlowski-

Kordesch and Rust 1994; Smoot and Castens-Seidell 1994).

Throughout deposition of the Wellington Formation, an even longer-

term shift in climate is inferred based on a significant change in the relative

proportion of facies between the Midco Member and underlying Otoe

Member and Anhydrite sequence. The lower part of the interval (,50 m,

Otoe Member and Anydrite sequence; Fig. 3) contains a substantially

larger percentage of facies reflecting arid conditions, specifically the very

fine siltstone, red massive mudstone, laminated variegated mudstone, and

gypsum beds. In contrast, the upper part of the interval (,40 m, Midco

Member; Fig. 3) is composed of a markedly higher percentage of facies

reflecting more humid conditions, including the gray massive mudstone,

organic mudstone, and dolomite. Thus, the study section overall reflects a

shift from more arid conditions in the Otoe and Anhydrite members to

more humid (relative) conditions in the Midco Member (Fig. 3).

This model suggests a generally semiarid but highly seasonal climate

for the mid-continent in late Early Permian time. Many have inferred that

zonal circulation in western and central tropical Pangea during the

Pennsylvanian shifted to increasingly monsoonal and thus, increasingly

seasonal climate in the Permian (Parrish 1993; Gibbs et al. 2002; G.

Soreghan et al. 2002; Tabor and Montan˜ez 2002). The provenance data

from the Wellington suggest that sediment emanated from both the west-

northwest (ARM) and south-southeast (Ouachita Mountains; in paleo-

coordinates). This implies northwesterly and south-southeasterly winds

(Fig. 9) if: 1) the Wellington sediments were eolian-sourced and 2) the

dust source remained proximal to the original basement source. Relating

these interpretations to the depositional model of the Wellington, the

laminated and massive (paleosols) mudstones represent more humid

periods associated with wetter times accompanied by south (easterlies),

whereas loess deposits (very fine siltstone facies) represent drier

conditions with increased aridity and seasonal westerlies.

The temporal and lateral extent of this lake system is difficult to

constrain based on the core and associated outcrops of this study.

Delineating the size of this inferred lake system is also hindered by the

lack of other detailed sedimentologic studies of the Wellington that would

define potential lacustrine deposits. Nevertheless, previous workers have

correlated individual marker beds in the Midco and Otoe members of the

Wellington between northern Oklahoma and central Kansas, over 220 km

(Fig. 1; Raasch 1946; Hall 2004). Employing the simplifying assumption

that this outcrop belt represents the minimal diameter of a circular lake,

this suggests a single lake of over 37,000 km

. This speculative but

supportable calculation paints a paleogeographic portrait of the Early

Permian Midcontinent that differs substantially from previous interpre-

tations and provides testable hypotheses for future studies.

CONCLUSIONS

1. The lithologic and geochemical data presented in this study, coupled

with data from earlier studies, suggest that the Lower Permian

Wellington Formation of Oklahoma records continental (lacustrine

and loess) deposition rather than marginal marine (sabkha, tidal).

The chemical facies forms only 10% of the Wellington and comprises

1) predominantly fine-grained laminated dolomite interlaminated

with organic-rich mudstone that records subaqueous suspension

deposition and 2) gypsum that consists of several primary morphol-

ogies reflecting deposition in subaqueous and shallow subsurface

(displacive) environments, but exhibit Sr isotope compositions

inconsistent with Permian seawater. Siliciclastic facies make up most

of the Wellington and reflect both subaqueous suspension and eolian

deposition but overall eolian transport. The clastic facies shows no

indication of tidal or sabkha features. Common overprinting by

Vertisol pedogenic features also points to a continental setting.

2. Deposition of the Wellington Formation occurred in a range of

related environments that included perennial freshwater lacustrine,

perennial saline lacustrine, ephemeral lacustrine (playa), and loess

accumulations. These fluctuations suggest strong climatic control

on the facies successions on various scales. Seasonality in climate is

suggested by alternations of laminated sediment, Vertisols, and

842 J.M. GILES ET AL.

JSR

fossils (e.g., conchostraca). Longer-term climatic change is indicat-

ed by facies successions that reflect transitions from a perennial

freshwater lake with primary dolomite growth to a shallower, saline

lake with subaqueous gypsum growth and laminated mudstone to a

dry saline pan with development of mudcracks (desiccation stage),

pedogenic overprinting, and loess accumulation.

3. Geochemical and detrital zircon data indicate a mixed provenance

for the volumetrically predominant siliciclastic component, with

both south-southeastern (Ouachita and possibly Mexico) and

western (ARM) sources.

4. Evidence from this study is consistent with the interpretations of

Benison and Goldstein (2001) suggesting that a large area of

shallow lakes existed in the Midcontinent during the Permian.

Other coeval deposits should be re-examined for possible alternate

interpretations, which could fundamentally shift our view of the

Permian in the Midcontinent.

ACKNOWLEDGMENTS

We thank the Oklahoma Geological Survey, especially J. Chaplin, for

logistical support in core analysis. G. Morgan, A. Madden, and R.

Turner assisted in chemical and mineralogical analysis. G. Augsburger

(OU) conducted the detrital zircon analysis, and G. Gehrels provided

support in the LaserChron Facility at the University of Arizona. T.

Rasbury, SUNY Stony Brook, provided Sr isotopic data. We also thank

T. Ruble at Hubble Geochemical Services, who provided complimentary

organic geochemical analyses. J. Pack thanks her family for their

dedication and support. We thank E. Gierlowski-Kordesch and an

anonymous reviewer for substantially improving an earlier version of this

manuscript, although they do not necessarily agree with all of our

interpretations. Funding for this project was provided by the U.S.

National Science Foundation (EAR-0746042 and EAR-1053018). Any

opinions, findings, and conclusions or recommendations expressed in this

material are those of the author(s) and do not necessarily reflect the view

of the National Science Foundation.

Appendix 1 contains the U-Pb geochronologic analyses of detrital zircons

in the Wellington Formation siltstone and is available from JSR’s Data

Archive: http://sepm.org/pages.aspx?pageid5229.

REFERENCES

LGEO

, T.J.,

AND

ECKEL

, P.H., 2008, The Late Pennsylvanian Midcontinent Sea of

North America: a review: Palaeogeography, Palaeoclimatology, Palaeoecology,

v. 268, p. 205–221.

LLEN

, R.A.,

AND

OLLINSON

, J.D., 1986, Lakes, in Reading, H.G., ed., Sedimentary

Environments and Facies: Oxford, U.K., Blackwell Scientific Publications, p. 63–94.

LONSO

-Z

ARZA

, A.M., Z

HAO

, Z., S

ONG

, C., L

, J., Z

HANG

, J., M

ARTI

´N

-P

´REZ

, A., M

ARTI

´N

ARCI

´A

, R., W

ANG

, X., Z

HANG

, Y.,

AND

HANG

, M., 2009, Mudflat/distal fan and

shallow lake sedimentation (upper Vallesian–Turolian) in the Tianshui Basin, Central

China: evidence against the late Miocene eolian loess: Sedimentary Geology, v. 222,

p. 42–51.

ABCOCK

, L.E., D

ANIEL

, F.M.,

AND

ONALD

, R.W., 2000, Paleolimulus, an early limuline

(Xiphosurida), from Pennsylvanian through Permian Lagersttten of Kansas and

taphonomic comparison with modern Limulus: Lethaia, v. 33, p. 129–141.

ECKEMEYER

, R.J.,

AND

ALL

,J.D.,2007,TheentomofaunaoftheLowerPermianfossil

insect beds of Kansas and Oklahoma, USA: African Invertebrates, v. 48, p. 23–39.

ECKER

, T.P., T

HOMAS

, W.A., S

AMSON

, S.D.,

AND

EHRELS

, G.E., 2005, Detrital zircon

evidence of Laurentian crustal dominance in the lower Pennsylvanian deposits of the

Alleghanian clastic wedge in eastern North America: Sedimentary Geology, v. 182,

p. 59–86.

ENISON

, K.C.,

AND

OLDSTEIN

, R.H., 2000, Sedimentology of ancient saline pans: an

example from the Permian Opeche Shale, Williston Basin, North Dakota, U.S.A.:

Journal of Sedimentary Research, v. 70, p. 159–169.

ENISON

, K.C.,

AND

OLDSTEIN

, R.H., 2001, Evaporites and siliciclastics of the Permian

Nippewalla Group of Kansas, USA: a case for non-marine deposition in saline lakes

and saline pans: Sedimentology, v. 48, p. 165–188.

ENISON

, K.C.

AND

OLDSTEIN

, R.H., 2002, Recognizing acid lakes and groundwaters in

the rock record: Sedimentary Geology, v. 151, p. 177–185.

ENISON

, K.C., B

OWEN

, B.B., O

BOH

-I

KUENOBE

, F.E., J

AGNIECKI

,E.A.,L

ACLAIR

, D.A.,

TORY

, S.L., M

ORMILE

, M.R.,

AND

ONG

,B.Y.,2007,Sedimentologyofacidsaline

lakes in southern western Australia: newly described processes and products of an

extreme environment: Journal of Sedimentary Research, v. 77, p. 366–388.

ERG

,J.A.,1977,PetrographyandBromineGeochemistryoftheHutchinsonSalt

Member of the Wellington Formation in Ellsworth County, Kansas: a paleoenviron-

mental analysis [unpublished M.S. thesis]: University of Kansas, Lawrence, 74 p.

LAKEY

,R.C.,2007,Carboniferous–Permianpaleogeographyoftheassemblyof

Pangaea, in Wong, T.E., ed., Proceedings of the XVth International Congress on

Carboniferous and Permian stratigraphy, Utrecht, 10–16 August 2003: Amsterdam,

Royal Dutch Academy of Arts and Sciences, p. 443–456.

OARDMAN

, D.R.I., 1999, Changes in patterns of cyclicity in Upper Carboniferous

through Lower Permian (Virgilian–Sakmarian) depositional sequences in the North

American Midcontinent [abstract], in Merriam, D.F., ed., Transactions of the 1999

American Association of Petroleum Geologists Midcontinent Section Meeting:

Lawrence, Kansas, Kansas Geological Survey Open-File Report 99-28, p. 86.

OLHAR

, R.,

AND

RANENDONK

, M., 2007, A non-marine depositional setting for

the northern Fortescue Group, Pilbara Craton, inferred from trace element

geochemistry of stromatolitic carbonates: Precambrian Research, v. 155, p. 229–250.

OWLER

, J.M., 1986, Spatial variability and hydrologic evolution of Australian lake

basins: analogue for Pleistocene hydrologic change and evaporite formation:

Palaeogeography, Palaeoclimatology, Palaeoecology, v. 54, p. 21–41.

REUNING

-M

ADSEN

, H.,

AND

WADZI

, T.W., 2005, Harmattan dust deposition and

particle size in Ghana: Catena, v. 63, p. 23–38.

UTLER

,B.E.,1956,Parna:anaeolianclay:AustralianJournalofScience,v.18,p.145–

151.

ALVO

, J.P., B

LANC

-V

ALLERON

, M.M., R

ODRIGUEZ

-A

RANDA

, J.P., R

OUCHY

, J.M.,

AND

ANZ

, M.E., 1999, Authigenic clay minerals in continental evaporitic environments, in

International Association of Sedimentologists, Special Publication 27, p. 129–151.

ARLSON

,K.J.,1968,TheskullmorphologyandestivationofburrowsofthePermian

lungfish, Gnathorhiza serrata: Journal of Geology, v. 76, p. 641–663.

ARLSON

, K.J., 1999, Crossotelos, an Early Permian nectridean amphibian: Journal of

Vertebrate Paleontology, v. 19, p. 623–631.

ARR

, T.R., 1982, Log-linear models, Markov chains and cyclic sedimentation: Journal

of Sedimentary Petrology, v. 52, p. 905–912.

ARTER

, L.S., K

ELLEY

, S.A., B

LACKWELL

, D.D.,

AND

AESER

, N.D., 1998, Heat flow and

thermal history of the Anadarko Basin, Oklahoma: American Association of

Petroleum Geologists, Bulletin, v. 82, p. 291–316.

HAPLIN

, J.R., 1988, Lithostratigraphy of Lower Permian rocks in Kay County, north-

central Oklahoma, and their stratigraphic relationships to lithic correlatives in Kansas

and Nebraska, in Morgan, W.A., and Babcock, J.A., eds., Permian Rocks of the

Midcontinent: Tulsa, Mid-Continent Section, SEPM, Special Publication 1, p. 79–

111.

HAPLIN

, J.R., 2004, Core drilling and stratigraphic analysis of Lower Permian rocks,

northern Oklahoma shelf, Kay County, Oklahoma: Oklahoma Geological Survey,

Special Publication 2004-1, 173 p.

HILINGAR

, G.V., 1957, Classification of limestones and dolomites on basis of Ca/Mg

ratio: Journal of Sedimentary Petrology, v. 27, p. 187–189.

LEMMENSEN

, L., 1979, Triassic lacustrine red-beds and palaeoclimate: the ‘‘Buntsand-

stein’’ of Helgoland and the Malmros Klint Member of East Greenland: Geologische

Rundschau, v. 68, p. 748–774.

OHEN

, A., 1989, Facies relationships and sedimentation in large rift lakes and

implications for hydrocarbon exploration: examples from Lakes Turkana and

Tanganyika: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 70, p. 65–80.

ONDIE

, K.C.,

AND

ELVERSTONE

,J.,1999,ThecrustoftheColoradoPlateau:newviews

of an old arc: Journal of Geology, v. 107, p. 387–397.

ROWELL

, J.C., 1999, Pre-Mesozoic Ice Ages: Their Bearing on Understanding the

Climate System: Geological Society of America, Memoir 192, 112 p.

ULLERS

, R.L., 1994, The controls on the major and trace element variation of shales,

siltstones, and sandstones of Pennsylvanian–Permian age from uplifted continental

blocks in Colorado to platform sediment in Kansas, USA: Geochimica et

Cosmochimica Acta, v. 58, p. 4955–4972.

AVYDOV

, V.I., C

ROWLEY

, J.L., S

CHMITZ

, M.D.,

AND

OLETAEV

,V.I.,2010,High-

precision U-Pb zircon age calibration of the global Carboniferous time scale and

Milankovitch-band cyclicity in the Donets Basin, eastern Ukraine: Geochemistry,

Geophysics, Geosystems, v. 11, no. Q0AA04, 22 p.

ECKKER

, P.D.,

AND

AST

, W.M., 1988, Modern dolomite deposition in continental,

saline lakes, western Victoria, Australia: Geology, v. 16, p. 29–32.

ESBOROUGH

, G.A., 1978, A biogenic–chemical stratified lake model for the origin of oil

shale of the Green River Formation: an alternative to the playa-lake model:

Geological Society of America, Bulletin, v. 89, p. 961–971.

OTO

,R.H.,1980,PennsylvanianstratigraphyandhistoryofColorado,inKent,

H.C., and Porter, K.W., eds., Colorado Geology: Rocky Mountain Association of

Geologists, 1980 Symposium, p. 37–50.

ICKINSON

, W.R.,

AND

EHRELS

, G.E., 2003, U-Pb ages of detrital zircons from Permian

and Jurassic eolian sandstones of the Colorado Plateau, USA: Paleogeographic

implications: Sedimentary Geology, v. 163, p. 29–66.

ICKINSON

, W.R.,

AND

EHRELS

, G.E., 2008, Sediment delivery to the Cordilleran

foreland basin: insights from U-Pb ages of detrital zircons in Upper Jurassic and

Cretaceous strata of the Colorado Plateau: American Journal of Science, v. 308,

p. 1041.

RIESE

, S.,

AND

OTT

, R., 1984, Model for sandstone–carbonate ‘‘cyclothems’’ based on

upper member of Morgan Formation (Middle Pennsylvanian) of northern Utah and

Colorado: American Association of Petroleum Geologists, Bulletin, v. 68, p. 574–597.

UNBAR

,C.,1924,KansasPermianinsects,Part1,thegeologicoccurrenceandthe

environment of the insects: American Journal of Science, v. 7, p. 171–209.

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 843

JSR

UNBAR

, C., B

AKER

, A., C

OOPER

, G.A., K

ING

, P., M

, E., M

ILLER

, A., M

OORE

, R.,

EWELL

, N., R

OMER

, A.,

AND

ELLARDS

, E., 1960, Correlation of the Permian

formations of North America: Geological Society of America, Bulletin, v. 71, p. 1763.

LROD

, D., 1980, A Geochemical and Petrographic Survey of the Wellington

Formation, North-Central Oklahoma [unpublished M.S. thesis]: Oklahoma State

University, Stillwater, 100 p.

VANS

, R., J

EFFERSON

, I., K

UMAR

, R., O’H

ARA

-D

HAND

, K.,

AND

MALLEY

, I., 2004, The

nature and early history of airborne dust from North Africa; in particular the Lake

Chad basin: Journal of African Earth Sciences, v. 39, p. 81–87.

,R.,1964,TheBlaineandRelatedFormationsofNorthwesternOklahomaand

Southern Kansas: Oklahoma Geological Survey, Bulletin 98, 238 p.

IELDING

, C., F

RANK

, T.,

AND

SBELL

, J., 2008, The late Paleozoic ice age: a review of

current understanding and synthesis of global climate patterns, in Geological Society

of America, Special Paper 441, p. 343–354.

ISCHBEIN

, S., J

OECKEL

, R.,

AND

IELDING

,C.,2009,Fluvial–estuarinereinterpretationof

large, isolated sandstone bodies in epicontinental cyclothems, Upper Pennsylvanian,

northern Midcontinent, USA, and their significance for understanding late Paleozoic

sea-level fluctuations: Sedimentary Geology, v. 216, p. 15–28.

OLK

,R.L.,1973,CarbonatepetrographyinthePost-SorbianAge:JohnsHopkins

University, Studies in Geology, v. 21, p. 118–158.

ARCI

´A

URA

, M., C

ALVO

, J.P., O

RDONEZ

, S., J

ONES

, B.F.,

AND

˜AVERAS

, J.C.,

2001, Petrographic and geochemical evidence for the formation of primary, bacterially

induced lacustrine dolomite: La Roda ‘‘white earth’’(Pliocene, central Spain):

Sedimentology, v. 48, p. 897–915.

ARRELS

, R.,

AND

ACKENZIE

, F., 1971, Evolution of Sedimentary Rocks: New York,

W.W. Norton and Company, 397 p.

EHRELS

, G.E., V

ALENCIA

, V.A.,

AND

UIZ

,J.,2008,Enhancedprecision,accuracy,

efficiency, and spatial resolution of U-Pb ages by laser ablation–multicollector–

inductively coupled plasma–mass spectrometry: Geochemistry Geophysics Geosys-

tems, v. 9, no. Q03017, p. 1–13.

IBBS

, M., R

EES

, P., K

UTZBACH

, J., Z

IEGLER

, A., B

EHLING

, P.,

AND

OWLEY

, D., 2002,

Simulations of Permian climate and comparisons with climate sensitive sediments:

Journal of Geology, v. 110, p. 33–55.

IBERT

, L., O

RTI

, F.,

AND

OSELL

, L., 2007, Plio-Pleistocene lacustrine evaporites of the

Baza Basin (Betic Chain, SE Spain): Sedimentary Geology, v. 200, p. 89–116.

IERLOWSKI

-K

ORDESCH

, E.,

AND

UST

,B.,1994,TheJurassicEastBerlinFormation,

Hartford Basin, Newark Supergroup (Connecticut and Massachusetts); a saline lake–

playa–alluvial plain system, in Renaut, R.W., and Last, W.M., eds., Sedimentology

and Geochemistry of Modern and Ancient Saline Lakes: SEPM, Special Publication

50, p. 249–265.

ILBERT

, M., 1992, Speculations on the origin of the Anadarko Basin, in Mason, R., ed.,

Basement Tectonics: International Basement Tectonics Association, Publication 7,

p. 195–208.

ILBERT

, M., 2002, Estimating topographic heights in the Permian Wichita Mountains,

Oklahoma [abstract]: Geological Society of America, Abstracts with Programs, v. 34,

p. 472.

LEASON

, J.D., P

ATCHETT

, P.J., D

ICKINSON

, W.R.,

AND

UIZ

,J.,1995,Ndisotopic

constraints on sediment sources of the Ouachita–Marathon fold belt: Geological

Society of America, Bulletin, v. 107, p. 1192–1210.

LEASON

, J.D., G

EHRELS

, G.E., D

ICKINSON

, W.R., P

ATCHETT

, P.J.,

AND

RING

, D.A.,

2007, Laurentian sources for detrital zircon grains in turbidite and deltaic sandstones

of the Pennsylvanian Haymond Formation, Marathon assemblage, west Texas, USA:

Journal of Sedimentary Research, v. 77, p. 888–900.

OEBEL

, K.A., B

ETTIS

, E.A., III,

AND

ECKEL

, P.H., 1989, Upper Pennsylvanian paleosol

in Stranger Shale and underlying Iatan Limestone, southwestern Iowa: Journal of

Sedimentary Petrology, v. 59, p. 224–232.

OLONKA

, J.A.,

AND

ORD

, D., 2000, Pangean (Late Carboniferous–Middle Jurassic)

paleoenvironment and facies: Palaeogeography, Palaeoclimatology, Palaeoecology,

v. 161, p. 1–34.

ALIVA

-C

OHEN

, A., S

TEIN

, M., G

OLDSTEIN

, S.L., S

ANDLER

, A.,

AND

TARINSKY

, A., 2012,

Sources and transport routes of fine detritus material to the Late Quaternary Dead

Sea basin: Quaternary Science Reviews, v. 50, p. 55–70.

ALL

, J., 2004, Depositional Facies and Diagenesis of the Carlton Member (Kansas)

and the Midco Member (Oklahoma) of the Wellington Formation (Permian, Sumner

Group) [unpublished M.S. thesis]: Wichita State University, Wichita, Kansas, 112 p.

ARDIE

, L.A., S

MOOT

, J.P.,

AND

UGSTER

, H.P., 1978, Saline lakes and their deposits; a

sedimentological approach, in Matter, A.T., ed., Modern and Ancient Lake

Sediments: Oxford, U.K., International Association of Sedimentologists, Special

Publication, no. 2, p. 7–41.

ASIOTIS

, S.T., M

ITCHELL

, C.E.,

AND

UBIEL

, R.F., 1993, Application of morphologic

burrow interpretations to discern continental burrow architects: lungfish or crayfish?

Ichnos, v. 2, p. 315–333.

ECKEL

,P.H.,1986,Sea-levelcurveforPennsylvanianeustaticmarinetransgressive–

regressive depositional cycles along Midcontinent outcrop belt, North America:

Geology, v. 14, p. 330–334.

ECKEL

, P.H., 2007, Advances in interpretive sedimentology and stratigraphy associated

with study of Pennsylvanian glacial–eustatic cyclothems: Proceedings of the XVth

International Congress on Carboniferous and Permian Stratigraphy, p. 23–34.

ESSE

, P.P.,

AND

AINSH

,G.M.,2003,Australiandustdeposits:modernprocesses

and the Quaternary record: Quaternary Science Reviews, v. 22, p. 2007–2035.

OHNSON

, K., 1990, Hydrogeology and Karst of the Blaine gypsum–dolomite Aquifer,

Southwestern Oklahoma: Oklahoma Geological Survey, Special Publication 90-5,

31 p.

OHNSON

, K., A

MSDEN

, T., D

ENISON

, R., D

UTTON

, S., G

OLDSTEIN

, A., R

ASCOE

, B.,

UTHERLAND

, P.,

AND

HOMPSON

,D.,1989,GeologyofthesouthernMidcontinent:

Oklahoma Geological Survey, Special Publication 89-2, p. 12–20.

OHNSON

, K., N

ORTHCUTT

, R., H

INSHAW

, G.,

AND

INES

, K., 2001, Geology and

petroleum reservoirs in Pennsylvanian and Permian rocks of Oklahoma: Oklahoma

Geological Survey, Circular 104, 20 p.

OHNSON

, S., 1989, Significance of loessite in the Maroon Formation (Middle

Pennsylvanian to Lower Permian), Eagle Basin, northwest Colorado: Journal of

Sedimentary Petrology, v. 59, p. 782–791.

OHNSON

, T.C., S

CHOLZ

, C.A., T

ALBOT

, M.R., K

ELTS

, K., R

ICKETTS

, R., N

GOBI

, G.,

EUNING

, K., S

SEMMANDA

, I.,

AND

ILL

, J., 1996, Late Pleistocene desiccation of

Lake Victoria and rapid evolution of cichlid fishes: Science, v. 273, p. 1091–1093.

ONES

, C.L., 1965, Petrography of evaporites from the Wellington Formation near

Hutchinson, Kansas: United States Geological Survey, Bulletin B1201, p. 1–70.

UNGE

, C.E., 1969, Comments on the concentration of size distribution measurements of

atmospheric aerosols and a test of the theory of self-preserving size distribution:

Journal of Atmospheric Science, v. 26, p. 603–615.

LUTH

, C.F.,

AND

ONEY

, P.J., 1981, Plate tectonics of the Ancestral Rocky Mountains:

Geology, v. 9, p. 10–15.

ORTE

, C., J

ASPER

, T., K

OZUR

, H.W.,

AND

EIZER

,J.,2006,

Sr/

Sr record of Permian

seawater: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 240, p. 89–107.

OZUR

, H.W.,

AND

EEMS

, R.E., 2010, The biostratigraphic importance of conchos-

tracans in the continental Triassic of the northern hemisphere, in Lucas, S.G., ed., The

Triassic Timescale: Geological Society of London, Special Publication 334, no. 1,

p. 315–417.

UTZBACH

, J.E.,

AND

ALLIMORE

,R.G.,1989,Pangaeanclimates:megamonsoonsofthe

megacontinent: Journal of Geophysical Research, v. 94, p. 3341–3357.

AST

,W.M.,1990,Lacustrinedolomite:anoverviewofmodern,Holocene,and

Pleistocene occurrences: Earth-Science Reviews, v. 27, p. 221–263.

OWENSTEIN

, T., L

, J., B

ROWN

, C., R

OBERTS

, S., K

, T., L

, S.,

AND

ANG

,W.,1999,

200 ky paleoclimate record from Death Valley salt core: Geology, v. 27, p. 3–6.

OWENSTEIN

, T., H

EIN

, M., B

OBST

, A., J

ORDAN

, T., K

, T.,

AND

,S.,2003,An

assessment of stratigraphic completeness in climate-sensitive closed-basin lake

sediments: Salar de Atacama, Chile: Journal of Sedimentary Research, v. 73, p. 91–104.

UZA

,K.V.,1978,RegionalseismicandgeologicevaluationsofNemahaUplift,

Oklahoma, Kansas, and Nebraska: Oklahoma Geology Notes, v. 38, p. 49–58.

ACHEL

, H.G., 2004, Concepts and models of dolomitization: a critical reappraisal, in

Braithwaite, C.J.R., Rizzi, G., and Darke, G., eds., The Geometry and Petrogenesis of

Dolomite Hydrocarbon Reservoirs: Geological Society of London, Special Publica-

tion 235, p. 7–63.

ARTENS

, U., W

EBER

, B.,

AND

ALENCIA

, V.A., 2010, U/Pb geochronology of Devonian

and older Paleozoic beds in the southeastern Maya block, Central America: Its

affinity with peri-Gondwanan terranes: Geological Society of America, Bulletin,

v. 122, p. 815–829.

AZZULLO

,S.J.,1999,EustaticandtectoniccontrolsoncyclicdepositioninLower

Permian ramp facies (Chase Group and basal Wellington formation) in the U.S.

Midcontinent, in Harris, P.M., Saller, A.H., and Simo, J.A., eds., Advances in

Carbonate Sequence Stratigraphy: Application to Reservoirs, Outcrops, and Models:

SEPM, Special Publication 63, p. 151–168.

, E.D.,

AND

RIEL

,S.S.,1967,PaleotectonicInvestigationsofthePermian

System in the United States: United States Geological Survey, Professional Paper 515,

271 p.

ENNAN

,S.M.,H

EMMING

,S.,M

ANIEL

,D.K.,

AND

ANSON

, G.N., 1993,

Geochemical approaches to sedimentation, provenance, and tectonics, in Johnsson,

M.J., and Basu, A., eds., Processes Controlling the Composition of Clastic Sediments:

Geological Society of America, Special Paper 284, p. 21–40.

ONTENAT

, C., B

ARRIER

, P., O

TT D’

STEVOU

, P.,

AND

IBSCH

, C., 2007, Seismites: an

attempt at critical analysis and classification: Sedimentary Geology, v. 196, p. 1–4.

ETTLETON

, W.D.,

AND

LEEMAN

,J.R.,1985,Micromorphologyofvertisols,inDouglas,

L.A., and Thompson, M.L., eds., Soil Micromorphology and Soil Classification:

Madison, Soil Science of America, Special Publication 15, p. 165–196.

ICHOLSON

,S.E.,1999,HistoricalandmodernfluctuationsofLakesTanganyikaand

Rukwa and their relationship to rainfall variability: Climate Change, v. 41, p. 53–71.

URY

, D.,

AND

CHREIBER

, B.C., 1997, The Paleogene basins of southern Provence, in

Busson, G., and Schreiber, B.C., eds., Sedimentary Deposition in Rift and Foreland

Basins in France and Spain (Paleogene and Lower Neogene): New York, Columbia

University Press, p. 240–300.

O’C

ONNOR

, H., Z

ELLER

, D., B

AYNE

, C., J

EWETT

, J.,

AND

WINEFORD

,A.,1968,Permian

System, in Zeller, D., ed., The Stratigraphic Succession in Kansas: Kansas Geological

Survey, Bulletin 189, p. 43–53.

LSEN

,P.,1986,A40-million-yearlakerecordofEarlyMesozoicorbitalclimatic

forcing: Science, v. 234, p. 842–848.

ACK

, J.M., 2010, Paleoclimatic Implications of the Depositional Setting and Origin of

Sediments in the Wellington Formation, Kay County, Oklahoma [unpublished M.S.

thesis]: University of Oklahoma, Norman, Oklahoma, 192 p.

ARK

, L.E.,

AND

IERLOWSKI

-K

ORDESCH

, E.H., 2007, Paleozoic lake faunas: establishing

aquatic life on land: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 249,

p. 160–179.

ARRISH

, J.T., 1993, Climate of the supercontinent of Pangea: Journal of Geology,

v. 101, p. 215–233.

OPPE

,L.J.,P

ASKEVICH

,V.F.,H

ATHAWAY

,J.C.,

AND

LACKWOOD

, D.S., 2002,

A Laboratory Manual for X-Ray Powder Diffraction: U.S. Geological Survey,

Open-File Report 1-41, 88 p.

844 J.M. GILES ET AL.

JSR

RICE

, J., H

OGAN

, J.,

AND

ILBERT

, M., 1996, Rapakivi texture in the Mount

Scott granite, Wichita mountains, Oklahoma: European Journal of Mineralogy,

v. 8, p. 435.

, K., 1987, Aeolian Dust and Dust Deposits: London, Academic Press Inc., 334 p.

IANG

, M., C

HEN

, F., Z

HANG

, J., Z

, R., J

, M., Z

HOU

, A.,

AND

IAO

, S., 2007, Grain

size in sediments from Lake Sugan: a possible linkage to dust storm events at the

northern margin of the Qinghai–Tibetan Plateau: Environmental Geology, v. 51,

p. 1229–1238.

IAO

, Y., Z

HAO

, Z., W

ANG

, Y., F

, J., W

ANG

, S.,

AND

IANG

, F., 2009, Variations of

geochemical compositions and the paleoclimatic significance of a loess–soil sequence

from GarzeˆCountyofwesternSichuanProvince,China:ChineseScienceBulletin,

v. 54, p. 4697–4703.

AASCH

, G.O., 1946, The Wellington Formation in Oklahoma [unpublished Ph.D.

thesis]: University of Wisconsin, Madison, 157 p.

EHEIS

, M.C., G

OODMACHER

, J.C., H

ARDEN

, J.W., M

ADDEN

,L.D.,R

OCKWELL

, T.K.,

HROBA

, R.R., S

OWERS

, J.M.,

AND

AYLOR

, E.M., 1995, Quaternary soils and dust

deposition in southern Nevada and California: Geological Society of America,

Bulletin, v. 107, p. 1003–1022.

ETALLACK

, G.J., 1990, Soils of the Past; An Introduction to Paleopedology: Boston,

Unwin Hyman, 520 p.

´NCHEZ

-R

OMA

´N

, M., V

ASCONCELOS

, C., S

CHMID

, T., D

ITTRICH

, M., M

ENZIE

, J.A.,

ENOBI

, R.,

AND

IVADENEYRA

,M.A.,2008,Aerobicmicrobialdolomiteatthe

nanometer scale: implications for the geologic record: Geology, v. 36, p. 879–882.

´NCHEZ

-R

OMA

´N

, M., M

ENZIE

, J.A.,

UCA

EBELLO

AGENER

, A., R

IVADENEYRA

M.A.,

AND

ASCONCELOS

, C., 2009, Presence of sulfate does not inhibit low-temperature

dolomite precipitation: Earth and Planetary Science Letters, v. 285, p. 131–139.

ANZ

-M

ONTERO

, M.E., R

ODRIGUEZ

-A

RANDA

, J.P.,

AND

EREZ

-S

OBA

, C., 2009, Microbial

weathering of Fe-rich phyllosilicates and formation of pyrite in the dolomite

precipitating environment of a Miocene lacustrine system: European Journal of

Mineralogy, v. 21, p. 163–175.

CHREIBER

, B.C., 1978, Environments of Subaqueous Gypsum Deposition: SEPM, Short

Course 4, p. 43–73.

CHULTZ

, D.J., 1975, Crystalline Silica in Mudrocks [unpublished M.S. thesis]:

University of Oklahoma, Norman, Oklahoma, 48 p.

COTESE

, C.R., B

AMBACH

, R.K., B

ARTON

, C., V

, R.V.D.,

AND

IEGLER

,A.M.,1979,

Paleozoic base maps: Journal of Geology, v. 87, p. 217–277.

MALLEY

, I., K

UMAR

, R., O’H

ARA

HAND

, K., J

EFFERSON

, I.,

AND

VANS

, R., 2005, The

formation of silt material for terrestrial sediments: Particularly loess and dust:

Sedimentary Geology, v. 179, p. 321–328.

MITH

, G.,

AND

ISCHOFF

, J., 1997, An 800,000-Year Paleoclimatic Record from Core

OL-92, Owens Lake, Southeast California: Geological Society of America, Special

Paper 317, 165 p.

MITH

, G., B

ARCZAK

, V., M

OULTON

, G.,

AND

IDDICOAT

,J.,1983,CoreKM-3,aSurface-

to-Bedrock Record of Late Cenozoic Sedimentation in Searles Valley, California: U.S.

Geological Survey, Professional Paper 1256, 24 p.

MOOT

, J.P., 1993, Field trip guide: Quaternary–Holocene–Lacustrine Sediments of

Lake Lahontan, Truckee River Canyon North of Wadsworth, Nevada: U.S.

Geological Survey, Open-File Report 93-0689, 35 p.

MOOT

, J.P.,

AND

ASTENS

-S

EIDELL

, B., 1994, Sedimentary features produced by

efflorescent salt crusts, Saline Valley and Death Valley, California, in Renaut,

R.W., and Last, W.M., eds., Sedimentology and Geochemistry of Modern and

Ancient Saline Lakes: SEPM, Special Publication 50, p. 73–90.

MOOT

, J.P.,

AND

OWENSTEIN

, T.K., 1991, Depositional environments of non-marine

evaporites, in Melvin, J., ed., Evaporites, Petroleum, and Mineral Resources:

Amsterdam, Elsevier, Developments in Sedimentology 50, p. 189–347.

OREGHAN

, G.S.,

AND

OREGHAN

, M.J., 2013, Tracing clastic delivery to the Permian

Delaware Basin, U.S.A.: implications for paleogeography and circulation in

westernmost equatorial Pangea: Journal of Sedimentary Research, v. 83, p. 786–802.

OREGHAN

, G., E

LMORE

, R.,

AND

EWCHUK

, M., 2002, Sedimentologic–magnetic record

of western Pangean climate in upper Paleozoic loessite (lower Cutler beds, Utah):

Geological Society of America, Bulletin, v. 114, p. 1019–1035.

OREGHAN

, G.S., K

ELLER

, G.R., G

ILBERT

, M.C., C

HASE

, C.G.,

AND

WEET

, D.E., 2012,

Load-induced subsidence of the Ancestral Rocky Mountains recorded by preservation

of Permian landscapes: Geosphere 8, p. 654–668.

OREGHAN

, M.J.,

AND

OREGHAN

,G.S.,2007,Whole-rockgeochemistryofupper

Paleozoic loessite, western Pangaea: implications for paleo-atmospheric circulation:

Earth and Planetary Science Letters, v. 255, p. 117–132.

OREGHAN

, M., S

OREGHAN

, G.,

AND

AMILTON

, M., 2002, Paleowinds inferred from

detrital-zircon geochronology of upper Paleozoic loessite, western equatorial Pangea:

Geology, v. 30, p. 695–698.

OREGHAN

, M.J., S

OREGHAN

, G.S.,

AND

AMILTON

, M.A., 2008, Glacial–interglacial

shifts in atmospheric circulation of western tropical Pangaea: Palaeogeography,

Palaeoclimatology, Palaeoecology, v. 268, p. 260–272.

OYINKA

, O.A.,

AND

LATT

, R.M., 2008, Identification and micro-stratigraphy of

hyperpycnites and turbidites in Cretaceous Lewis Shale, Wyoming: Sedimentology,

v. 55, p. 1117–1133.

PENCER

, R.J.,

AND

OWENSTEIN

,T.K.,1990,Evaporites:GeoscienceCanada,Reprint

Series, v. 4, p. 141–163.

UTTON

, S.J.,

AND

, L.S., 1996, Postdepositional chemical alteration of Ouachita

shales: Geological Society of America, Bulletin, v. 108, p. 978–991.

WANSON

, B.A.,

AND

ARLSON

, K.J., 2002, Walk, wade, or swim? Vertebrate traces on an

Early Permian lakeshore: Palaios, v. 17, p. 123–133.

WEET

, D.,

AND

OREGHAN

, G., 2010, Late Paleozoic tectonics and paleogeography of the

ancestral Front Range: structural, stratigraphic, and sedimentologic evidence from the

Fountain Formation (Manitou Springs, Colorado): Geological Society of America,

Bulletin, v. 122, p. 575–594.

WINEFORD

, A.,

AND

UNNELS

, R.T., 1953, Identification of polyhalite (a potash mineral)

in Kansas Permian salt: Kansas Academy of Science Transactions, v. 56, p. 364–

370.

ABOR

, N.,

AND

ONTAN

˜EZ

, I., 2002, Shifts in late Paleozoic atmospheric circulation

over western equatorial Pangea: insights from pedogenic mineral d

Ocompositions:

Geology, v. 30, p. 1127–1130.

ABOR

, N.J.A.,

AND

OULSEN

,C.J.,2008,PalaeoclimateacrosstheLatePennsylvanian–

Early Permian tropic al palaeolatitudes: a review of climate indicators, their

distribution, and relation to palaeophysiographic climate factors: Palaeogeography,

Palaeoclimatology, Palaeoecology, v. 268, p. 293–310.

ABOR

,N.J.,M

ONTAN

˜EZ

,I.P.,S

COTESE

,C.R.,P

OULSEN

,C.J.,

AND

ACK

,G.H,2008,

Paleosol archives of environmental and climatic history in paleotropical western

Pangea during the latest Pennsylvanian through Early Permian, in Fielding,

C.R., Frank, T.D., and Isbell, J.L., eds., Resolving the Late Paleozoic Ice Age

in Time and Space: Geological S ociety of America, Special Publication 441, p. 291–

303.

ASCH

, P., 1958, Permian Conchostracan-Bearing Beds of Kansas: Part 1. Jester Creek

Section: Fauna and Paleoecology: Journal of Paleontology, v. 32, p. 525–540.

ASCH

,P.,1961a,DataonsomenewLeonardianconchostracanswithobservationson

the taxonomy of the family vertexiidae: Journal of Paleontology, v. 35, p. 1121–1129.

ASCH

,P.,1961b,Paleolimnology:Part2,HarveyandWedgwickCounties,Kansas,

stratigraphy and biota: Journal of Paleontology, v. 35, p. 836–865.

ASCH

,P.,1962,Taxonomicandevolutionarysignificanceoftwonewconchostracan

genera from the Midcontinent Wellington Formation: Journal of Paleontology, v. 36,

p. 817–821.

ASCH

,P.,1964,PeriodicityintheWellingtonFormationofKansasandOklahoma:

Kansas Geological Survey, Bulletin 169, p. 481–496.

AYLOR

, S.R.,

AND

LENNAN

,S.M.,1985,TheContinentalCrust;ItsComposition

and Evolution; An Examination of the Geochemical Record Preserved in Sedimentary

Rocks: Oxford, Blackwell Scientific Publications, Geoscience Texts, 312 p.

AYLOR

, S.R.,

AND

ENNAN

,S.M.,2001,Chemicalcompositionandelement

distribution in the Earth’s crust, in Robert, A.M., ed., Encyclopedia of Physical

Science and Technology: New York, Academic Press, p. 697–719.

OTTEN

,M.W.,H

ANAN

,M.A.,

AND

EAVER

, B.L., 2000, Beyond whole-rock

geochemistry of shales: the importance of assessing mineralogic controls for revealing

tectonic discriminants of multiple sediment sources for the Ouachita Mountain flysch

deposits: Geological Society of America, Bulletin, v. 112, p. 1012–1022.

RUDINGER

,P.A.,C

HAMBERS

,L.A.,

AND

MITH

,J.W.,1985,Low-temperaturesulphatereduction:

biological versus abiological: Canadian Journal of Earth Sciences, v. 22, p. 1910–1918.

SOAR

, H.,

AND

,K.,1987,Dusttransportandthequestionofdesertloess

formation: Sedimentology, v. 34, p. 139–153.

WENHOFEL

,W.,1926,GeologyoftheMinganIslands:GeologicalSocietyofAmerica,

Bulletin, v. 37, p. 535–550.

ANDERVOORT

, D.S., 1997, Stratigraphic response to saline lake-level fluctuations and

the origin of cyclic nonmarine evaporite deposits: The Pleistocene Blanca Lila

Formation, northwest Argentina: Geological Society of America, Bulletin, v. 109,

p. 210–224.

CHMUS

, W., B

ICKFORD

, M., A

NDERSON

, J., B

ENDER

, E., A

NDERSON

, R., B

AUER

, P.,

OBERTSON

, J., B

OWRING

, S., C

ONDIE

, K.,

AND

ENISON

, R., 1993, Transcontinental

Proterozoic provinces, Precambrian, The Geological Society of America, Geology of

North America, v. C-3, Conterminous US, p. 171–334.

ASCONCELOS

, C.,

AND

ENZIE

, J.A., 1997, Microbial mediation of modern dolomite

precipitation and diagenesis under anoxic conditions (Lagoa Vermelha, Rio de

Janerio, Brazil); Journal of Sedimentary Research v. 67, p. 378–390.

EEVERS

, J.J.,

AND

OWELL

, M., 1987, Late Paleozoic glacial episodes in Gondwanaland

reflected in transgressive–regressive depositional sequences in Euramerica: Geological

Society of America, Bulletin, v. 98, p. 475–487.

IEBE

, W.A., 1937, The Wellington Formation of central Kansas: Wichita

University, Bulletin 12, p. 3–18.

VON DER

ORCH

, C.C., 1976, Stratigraphy and formation of Holocene dolomitic

carbonate deposits of the Coorong area, South Australia: Journal of Sedimentary

Petrology, v. 46, p. 952–966.

ANLESS

, H.R.,

AND

HEPARD

,F.P.,1936,Sealevelandclimaticchangesrelatedtolate

Paleozoic cycles: Geological Society of America, Bulletin, v. 47, p. 1177–1206.

ARREN

, J.K., 1989, Evaporite Sedimentology: Importance in Hydrocarbon Accumu-

lation: Englewood Cliffs, New Jersey, Prentice-Hall, 285 p.

ARREN

, J.K.,

AND

ENDALL

, C.G.S

.C., 1985, Comparison of sequences formed in

marine sabkha (subaerial) and salina (subaqueous) settings; modern and ancient:

American Association of Petroleum Geologists, Bulletin, v. 69, p. 1013–1023.

ATNEY

,W.L.,B

ERG

, J.,

AND

AUL

,S.,1988,OriginanddistributionoftheHutchinson

Salt Member (lower Leonardian) in Kansas, in Morgan, W.A., and Babcock, J.A.,

eds., Permian Rocks of the Mid-Continent: Midcontinent SEPM, Special Publication

1, p. 113–135.

EBER

, B., S

CHAAF

, P., V

ALENCIA

, V.A., I

RIONDO

, A.,

AND

RTEGA

-G

UTIE

´RREZ

, F., 2006,

Provenance ages of late Paleozoic sandstones (Santa Rosa Formation) from the Maya

Block, SE Mexico: implications on the tectonic evolution of western Pangea: Revista

Mexicana de Ciencias Geolo´gicas, v. 23, p. 262–276.

LAKES, LOESS, AND PALEOSOLS IN THE PERMIAN WELLINGTON FORMATION OF OKLAHOMA 845

JSR

ILLIAMS

-S

TROUD

, S.C., 1994, The evolution of an inland sea of marine origin to a non-

marine saline lake: the Pennsylvanian Paradox salt, in Renaut, R.W., and Last, W.M.,

eds., Sedimentology and Geochemistry of Modern and Ancient Saline Lakes: SEPM,

Special Publication 50, p. 293–306.

ILSON

, B., 1927, Paleogeography of the upper Paleozoic rocks of Oklahoma:

Oklahoma Geological Survey, Bulletin 41, p. 22–86.

ILSON

, L., 1962, Permian plant microfossils from the Flowerpot Formation, Greer

County, Oklahoma: Oklahoma State Geological Survey, Circular 49, 50 p.

RIGHT

, V.P.,

AND

ARRIOTT

, S.B., 2007, The dangers of taking mud for granted:

lessons from Lower Old Red Sandstone dryland river systems of South Wales:

Sedimentary Geology, v. 195, p. 91–100.

IAO

,J.,A

,Z.,L

,T.,I

NOUCHI

,Y.,K

UMAI

,H.,Y

OSHIKAWA

,S.,

AND

ONDO

,Y.,1999,East

Asian monsoon variation during the last130,000 years: evidence from the LoessPlateau of

central China and Lake Biwa of Japan: Quaternary Science Reviews, v. 18, p. 147–157.

ANG

,S.V.,1985,PetrologicalandGeochemicalApproachestotheOriginoftheSan

Angelo–Flowerpot Red Beds (Permian) and Their Associated Stratiform Copper

Mineralizations in North Central Texas and Southwestern Oklahoma [unpublished

Ph.D. thesis]: University of Texas at Dallas, 318 p.

ECHIELI

, Y.,

AND

OOD

, W.W., 2002, Hydrogeologic processes in saline systems:

playas, sabkhas, and saline lakes: Earth-Science Reviews, v. 58, p. 343–365.

Received 4 January 2012; accepted 24 April 2012.

846 J.M. GILES ET AL.

JSR

Detecting upland glaciation in Earth’s pre-Pleistocene record

Article

Full-text available

Aug 2022

Earth has sustained continental glaciation several times in its past. Because continental glaciers ground to low elevations, sedimentary records of ice contact can be preserved from regions that were below base level, or subject to subsidence. In such regions, glaciated pavements, ice-contact deposits such as glacial till with striated clasts, and glaciolacustrine or glaciomarine strata with dropstones reveal clear signs of former glaciation. But assessing upland (mountain) glaciation poses particular challenges because elevated regions typically erode, and thus have extraordinarily poor preservation potential. Here we propose approaches for detecting the former presence of glaciation in the absence or near-absence of ice-contact indicators; we apply this specifically to the problem of detecting upland glaciation, and consider the implications for Earth’s climate system. Where even piedmont regions are eroded, pro- and periglacial phenomena will constitute the primary record of upland glaciation. Striations on large (pebble and larger) clasts survive only a few km of fluvial transport, but microtextures developed on quartz sand survive longer distances of transport, and record high-stress fractures consistent with glaciation. Proglacial fluvial systems can be difficult to distinguish from non-glacial systems, but a preponderance of facies signaling abundant water and sediment, such as hyperconcentrated flood flows, non-cohesive fine-grained debris flows, and/or large-scale and coarse-grained cross-stratification are consistent with proglacial conditions, especially in combination with evidence for cold temperatures, such as rip-up clasts composed of noncohesive sediment, indicating frozen conditions, and/or evidence for a predominance of physical over chemical weathering. Other indicators of freezing (periglacial) conditions include frozen-ground phenomena such as fossil ice wedges and ice crystals. Voluminous loess deposits and eolian-marine silt/mudstone characterized by silt modes, a significant proportion of primary silicate minerals, and a provenance from non-silt precursors can indicate the operation of glacial grinding, even though such deposits may be far removed from the site(s) of glaciation. Ultimately, in the absence of unambiguous ice-contact indicators, inferences of glaciation must be grounded on an array of observations that together record abundant meltwater, temperatures capable of sustaining glaciation, and glacial weathering (e.g., glacial grinding). If such arguments are viable, they can bolster the accuracy of past climate models, and guide climate modelers in assessing the types of forcings that could enable glaciation at elevation, as well as the extent to which (extensive) upland glaciation might have influenced global climate.

A new isochron for stratigraphic correlation in the Permian Delaware Basin and beyond

Article

Sep 2023
MAR PETROL GEOL

Altered volcanic ash, preserved as bentonite clay within sedimentary depositional units, can facilitate regional stratigraphic correlation. While many bentonite ash beds have been documented in core extracted over decades of hydrocarbon exploration in the Delaware Basin, a particular ~1 cm-thick bentonite has been identified at a distinct stratigraphic position, at a sedimentary facies transition from thin-bedded calciclastic turbidites to thick�bedded siliciclastic turbidites, in the compositionally-mixed upper Wolfcamp formation. A comparison of geochemical analyses of the ash from two cores and petrophysical correlations across eight wells was conducted to test the regional correlation of the ash. Despite diagenetic alteration since seafloor deposition ~280 Ma, nearly identical geochemical trends between incompatible elemental subsets, including light and heavy rare earth elements, large ion lithophiles, and high field strength elements, suggest that these two ash deposits originated from the same volcanic center. Detailed sedimentologic analyses and lithostratigraphic correlations across three cores spaced tens of km apart confirm that the ash bed is bound by correlative quiescent deepwater strata. Based on the chemical composition, probable timing of deposition, and proximity, we speculate that the Las Delicias Arc produced this ash, and it was transported by wind and deposited as a hemipelagite into the Delaware Basin deep marine environment. This discovery implies the existence of the ash marker in other cores within Late Paleozoic western equatorial Pangea, e.g. in compositionally-mixed deep marine deposits of the Midland Basin and outcropping deposits around the Greater Permian Basin and beyond, which would facilitate regional chronostratigraphic correlation for a critical time in Earth’s history.

A New Chronostratigraphic Datum for the Permian Delaware Basin and Beyond

Article

Jan 2023

EARLY EFFECTS OF THE LATE PALEOZOIC CLIMATE TRANSITION ON SOIL ECOSYSTEMS OF THE APPALACHIAN BASIN (CONEMAUGH, MONONGAHELA, AND DUNKARD GROUPS): EVIDENCE FROM ICHNOFOSSILS

Article

Full-text available

Nov 2022

Daniel I Hembree

The late Paleozoic transition is well represented by the upper Pennsylvanian to lower Permian Conemaugh, Monongahela, and Dunkard groups of the western Appalachian Basin (U.S.A.). These units contain abundant paleosols possessing suites of ichnofossils that serve as indicators of soil moisture, soil organic content, water table level, precipitation, and landscape stability. Analysis of these units can, therefore, be used to refine the details of how late Paleozoic terrestrial landscapes changed through time. A study along a 50 km west-east and a 40 km north-south transect through southeast Ohio and southwest West Virginia resulted in the recognition of 24 pedotypes with distinct ichnofossil assemblages. Ichnofossils include rhizoliths, Planolites, Palaeophycus, Taenidium, Scoyenia, Macanopsis, Skolithos, Cylindricum, cf. Psilonichnus, Arenicolites, mottles, and coprolites produced by various plants, gastropods, and larval-to-adult soil arthropods. Soil-forming environments include palustrine, levee, proximal to distal floodplain, interfluve, backswamp, marsh, and fen settings. An up-section shift in pedotypes from Argillisols to Vertisols and Calcisols as well as an overall increase in the diversity of pedotypes recorded a change in soil-forming conditions, resulting in a diverse landscape that changed significantly as mean annual precipitation rose and fell. An up-section increase in ichnofossil diversity in the paleosols and changes in ichnocoenoses suggests an increased dependence on the soil as a refuge and as a food resource. Overall, growing instability of the climate during the Pennsylvanian–Permian transition led to a more heterogeneous landscape that helped to promote colonization of a more diverse assemblage of soil organisms.

EARLY EFFECTS OF THE LATE PALEOZOIC CLIMATE TRANSITION ON SOILS AND SOIL ECOSYSTEMS OF THE APPALACHIAN BASIN (CONEMAUGH, MONONHAHELA, AND DUNKARD GROUPS)

Conference Paper

Jan 2022

Daniel I Hembree

BENTONITE ASH BED AS CHRONOSTRATIGRAPHIC DATUM FOR PERMIAN DELAWARE BASIN AND BEYOND

Conference Paper

Jan 2021

Permo-Triassic aeolian red clay of southwestern England and its palaeoenvironmental implications

Article

Jul 2021

Late Permian and Triassic red mudstones are widely distributed and exposed in southwestern England. This homogenous, massive mudstone succession has been extensively studied for its palaeoenvironmental potential. However, its origin and palaeoenvironment remain under debate. The Triassic Mercia mudstone was early proposed to be aeolian loessic clay based on collapse nature when wetted or loaded and its similarities with aeolian clay in Quaternary Australia, but lacks experimental confirmation and is not generally accepted. In comparison with aeolian red clay in China, here we confirmed that the Triassic Mercia mudstone, together with the Upper Permian Aylesbeare mudstone, was dominated by aeolian clay. This was based on lines of evidence regarding sedimentary structure, particle grain size, geochemistry, micromorphology, and pedogenic features. The results showed that the Mercia mudstone and the Aylesbeare mudstone had sedimentary structures and grain size distributions that were similar to the aeolian red clay in the Chinese Loess Plateau. The major chemical elements correlated well with the aeolian red clay, with the exception of minor discrepancies in CaO and K2O. The similarity in the rare earth element (REE) distribution of the Mercia mudstone and the Aylesbeare mustone with aeolian red clay inferred their similar origin. Widespread pedogenic features indicated the universal development of palaeovertisols forming in alternating wet/dry climates. It was hypothesised that Permo-Triassic southwestern England was dominated by aeolian dust accumulation in a seasonal wet/dry climate, whereas perennial lakes or longstanding rivers across the study area might not exist.

Testing extinction events and temporal shifts in diversification and fossilization rates through the skyline Fossilized Birth-Death (FBD) model: The example of some mid-Permian synapsid extinctions

Article

Apr 2024
CLADISTICS

In the last decade, the Fossilized Birth–Death (FBD) process has yielded interesting clues about the evolution of biodiversity through time. To facilitate such studies, we extend our method to compute the probability density of phylogenetic trees of extant and extinct taxa in which the only temporal information is provided by the fossil ages (i.e. without the divergence times) in order to deal with the piecewise constant FBD process, known as the “skyline FBD”, which allows rates to change between pre‐defined time intervals, as well as modelling extinction events at the bounds of these intervals. We develop approaches based on this method to assess hypotheses about the diversification process and to answer questions such as “Does a mass extinction occur at this time?” or “Is there a change in the fossilization rate between two given periods?”. Our software can also yield Bayesian and maximum‐likelihood estimates of the parameters of the skyline FBD model under various constraints. These approaches are applied to a simulated dataset in order to test their ability to answer the questions above. Finally, we study an updated dataset of Permo‐Carboniferous synapsids to get additional insights into the dynamics of biodiversity change in three clades (Ophiacodontidae, Edaphosauridae and Sphenacodontidae) in the Pennsylvanian (Late Carboniferous) and Cisuralian (Early Permian), and to assess support for end‐Sakmarian (or Artinskian) and end‐Cisuralian mass extinction events discussed in previous studies.

RECONHECENDO TOCAS FÓSSEIS DA ESTIVAÇÃO DE PEIXES PULMONADOS (SARCOPTERYGII, DIPNOI): ICNOTAXONOMIA E PALEOAMBIENTE

Article

Full-text available

Jul 2023

Recognizing lungfish (Sarcopterygii, Dipnoi) estivation burrows: ichnotaxonomy and paleoenvironment. Lungfishes first appeared on Earth around 350 million years ago in freshwater environments from Gondwana, since when they suffered harsh adaptations through the geological time, among which, the aestivation capability. Such a behavior keeps preserved in the geological record along the eras and the fossil burrows own a high potential for environmental inferences. From so much we developed this work aiming to (i) gather the records once published on this theme, (ii) to discuss the adopted standard by the authors for interpreting the burrows and their burrowers, and (iii) to discuss the paleoenvironmental significance of the lungfish burrows presenting a model of its probable occurrence in the landscape context. For such a purpose, we made the literature review searching for terms related to the theme, in different basis and pages of scientific journals. We have found 35 articles reporting new occurrences of lungfish burrows, besides uncertain or refuted records, according to ichnotaxonomical parameters. A large proportion of the papers inform about sedimentary facies and paleoenvironmental conditions. Essentially, the records occur in areas of shallow rivers and lakes of a semiarid to subtropical climate, with seasonal humidity variations, but also in coastal environments. Still, from the presented publications, we consider lungfish aestivation burrows to be safe paleoenvironmental indicators. Keywords: lungfish; aestivation; ichnofossils; ichnotaxonomy; floodplains; semiarid.

Plate tectonic control of strontium concentration in Phanerozoic and Neoproterozoic seawater: Evidence from fluid inclusions in marine halite

Article

Feb 2023
GEOCHIM COSMOCHIM AC

Chemical analyses of 1371 fluid inclusions in 131 halite samples with marine 87Sr/86Sr values were used to reconstruct the strontium concentrations [Sr]SW of Phanerozoic and Neoproterozoic seawater. [Sr]SW varied seven-fold and oscillated twice between high- and low-Sr concentrations over the past 550 million years (Myr), in rhythm with Ca-rich and SO4-poor paleoseawater intervals and calcite-aragonite seas. Variations in the [Sr]/[Ca]SW ratio from fluid inclusions were not significant over the past ~270 Myr, and are within ±3 µmol/mmol of the modern [Sr]/[Ca]SW ratio of ~8.5 µmol/mmol. These results agree with the [Sr]/[Ca]SW ratios obtained from fossil corals, benthic foraminifera, brachiopods, belemnites, and rudists. [Sr]/[Ca]SW in the early and middle Paleozoic was ~ 2 times the modern [Sr]/[Ca]SW ratio. A major shift of the [Sr]/[Ca]SW ratio in the late Permian coincided with the initial rifting of the Pangean supercontinent. Seawater 87Sr/86Sr ratios plotted against 1/[Sr]SW show two distinct linear correlations: negative correlation from 515–252 Ma and positive correlation from 150–0 Ma, suggesting different controls on the global Sr cycle between these intervals. The negative correlation coincides with the long-term assembly of Pangea in the Paleozoic (~500–250 Ma). The positive correlation from 150–0 Ma parallels the break-up of Pangea and the decrease of mid-ocean ridge (MOR) hydrothermal fluid flux and subduction zone length in the Mesozoic and Cenozoic.

Kansas Permian insects. Part 1. The geologic occurrence and the environment of the insects

Article

C.O. Dunbar

Model for Sandstone-Carbonate Cyclothems"Based on Upper Member of Morgan Formation (Middle Pennsylvanian) of Northern Utah and Colorado"

Article

Jan 1984
AAPG BULL

Steven G. Driese R. H. Dott, J

The upper member of the 200 m (660 ft) thick Morgan Formation (Middle Pennsylvanian) consists of 5-25 m (16-82 ft) thick, very fine-grained quartz sandstone units that are interbedded repetitively with 0.5-11 m (1.6-36 ft) thick, oolitic, bioclastic, peloidal, and micritic carbonate units. Similar repetitive sequences occur widely in western North America. The quartz sandstone-carbonate cyclothems defined by this study have potential as targets for hydrocarbon exploration. Both eolian dune sandstones and dolomitized shelf carbonate strata are locally important reservoir rocks in the subsurface in parts of the western Overthrust belt in Utah and Wyoming. 84 references, 22 figures, 4 tables.

Saline lakes and their deposits: A sedimentological approach

Article

Jan 1978

Speculations on the Origin of the Anadarko Basin

Chapter

Jan 1992

M. Charles Gilbert

The Anadarko Basin of the southern midcontinent, U.S.A., is the deepest cratonic basin in North America, with an existing in-place sedimentary section of 12–13 km. It has a more complex history than some other interior basins because it is both a cratonic and a foreland basin. It shares a common origin with several North American Paleozoic basins in having formed over a preexisting rift zone. This rift zone — the Southern Oklahoma Aulacogen — was unusual, having been formed athwart the suture between the southern 1.35–1.40 Ga Granite-Rhyolite terrane and the 1.2 Ga Texas era ton. The rift was active in the late Proterozoic-early Cambrian, but may have inherited an earlier Proterozoic grain. The Paleozoic Anadarko Basin was areally similar to present-day Michigan or Illinois, but was segmented and deepened in the Pennsylvanian during the Ouachita collision. It had a poorly recognized Permian phase which perhaps extended into the Mesozoic. The Anadarko Basin had a clear thermal subsidence phase in the early Paleozoic. The basin was reactivated in the Mississippian, and this reactivation presumably required plate margin interactions in some form. The basin was thrust-loaded in the Pennsylvanian. The Permian subsidence must also relate to 1) plate margin effects not well understood, and 2) compaction and diagenesis of the Pennsylvanian fill.

Micromorphology of Vertisols

Chapter

Jan 1985

Eustatic and Tectonic Controls on Cyclic Deposition in Lower Permian Ramp Facies (Chase Group and Basal Wellington Formation) in the U.S. Midcontinent

Chapter

Jan 1999

Salvatore Mazzullo

Cyclic marine carbonate and marine to terrestrial siliciclastic strata in the upper Wolfcampian Chase Group and basal Wellington Formation were deposited on a low-relief, south-sloping ramp overlying the buried Nemaha ridge. The section comprises eight depositional sequences, each of which consists of two higher-frequency cyclothems of transgressive-regressive character. Each cyclothem includes a transgressive systems tract and ensuing highstand systems tract, and the maximum flooding surface of each sequence consistently occurs in the basal cyclothem of that sequence. Cyclothems are separated by relative lowstand systems tracts of dominantly marginal-marine facies, whereas sequence boundaries are either regionally extensive unconformities or lowstand systems tracts of paleosols. Thickness and facies-stacking patterns of the sequences are arranged so as to define three third-order cycles; component sequences and cyclothems are regarded as fourth- and fifth-order cycles, respectively. The regional occurrence of these cycles is interpreted to suggest glacio-eustatic forcing. The complex internal architecture of the sequences reflects interplay among forcing parameters and periodic syndepositional tectonism along the Nemaha ridge. Although there is coincidence between maxima of tectonic activity and degree of architectural complexity of sequences within each third-order cycle, the episodic nature of tectonism does not appear to have been consistent enough to have forced cyclicity in this section. Rather, syndepositional tectonism merely overprinted thickness variations of systems tracts within sequences on the fundamentally glacio-eustatically forced sequence stratigraphic architecture of this section.

Plio-Pleistocene lacustrine evaporites of the Baza Basin (Betic Chain, SE Spain)

Article

Aug 2007
SEDIMENT GEOL

The Baza Basin (the eastern part of the Guadix-Baza Basin, in SE Spain) underwent a significant evaporitic sedimentation in non-marine settings during the Plio-Pleistocene. The largest of these settings developed in the central part of the basin as a shallow, saline lake system, where abundant gypsum deposits occur (Benamaurel and Galera Gypsum units). This paper studies these deposits from the cartographic, stratigraphic, sedimentologic, petrographic and isotopic points of view. All the gypsum has been preserved as primary enabling a good characterization of the environmental conditions of the original precipitates. Three interconnected subenvironments or zones -inner, intermediate and marginal- are differentiated in this saline lake system. In the inner zone (shallow to relatively deeper central lake), a regular alternation of gypsum and carbonate laminae accumulated suggesting a seasonal regime. Many of the gypsum laminae display size-gradation (both reverse and symmetrical) indicating free precipitation in a stable brine body. In the intermediate zone (mosaic of shallow lakes), carbonate (dolomitic) beds formed in association with dark lutite levels, gypsum beds, and gypsum nodules and micronodules. Moreover, anoxic conditions developed in this zone, which resulted in the formation of native sulphur occurrences of economic value. In the marginal zone, the evaporitic deposits are developed only locally (the Galera Gypsum unit, in particular). The various gypsum lithofacies in these marginal deposits suggest the presence of a number of shallow to exposed settings (saline mudflat, saline marsh and gypsiferous pond). The isotopic composition (delta S-34, delta O-18) of the gypsum samples is consistent with a Triassic origin of the sulphate as a result of chemical recycling. These data also suggest that a similar recycling mechanism operated in the saline lake system, where the gypsum sediments from the margins were coevally recycled towards the inner part. Both the evaporitic mineralogy and the gypsum and carbonate lithofacies suggest that semiarid conditions prevailed in this basin during the accumulation of the evaporite units. (c) 2007 Elsevier B.V. All rights reserved.

Carboniferous-Permian paleogeography of the assembly of Pangaea

Article

Jan 2007

R.C. Blakey

Log-Linear Models, Markov Chains and Cyclic Sedimentation

Article

Jan 1982

Timothy Carr

Quantitative techniques employing Markovian processes have been used by a number of investigators to test stratigraphic sections against a null hypothesis of a random succession of sedimentary facies. Rejection of the null hypothesis is used to imply presence of a Markov chain in a succession. However, many of these techniques possess serious statistical flaws arising from the structuring of facies transitions. The result is that presence of preferred facies and regular 'cyclic' behavior in sedimentary successions cannot be rigorously supported. Log-linear models, in conjunction with a stepwise procedure for identification of significant transitions, provide a rigorous method for determining the presence and extent of the Markov property in stratigraphic sections. A wide variety of geologic problems that are structured in terms of temporal succession can be examined as a Markov process using log-linear models. -Author.

Upper Pennsylvanian Paleosol in Stranger Shale and Underlying Iatan Limestone, Southwestern Iowa

Article

Jan 1989

Cores display characteristics other than the weathered-clay or caliche horizons or underclay type of paleosol profiles from the Upper Pennsylvanian in the Midcontinent. Paleosol features include clay-filled fractures and solution channels (cryptokarst) in the top of the Iatan Limestone which display some degree of secondary clay orientation along the edges (neostrians). Pedogenesis in this unit resulted from subaerial exposure during retreat of the sea following the transgressive-regressive marine cycle that deposited the Iatan Limestone. Solution-channelling of the top of the Iatan and leaching of clays within its fractures indicates initial exposure to a humid climate with strong meteoric flux. The Stranger paleosol, however, displays features of Entisol, Inceptisol, or Vertisol development in terrestrial deposits under a somewhat drier climate following the partial solution of the upper Iatan. -from Authors

Lakes, Loess, and Paleosols In the Permian Wellington Formation of Oklahoma, U.S.A.: Implications For Paleoclimate and Paleogeography of the Midcontinent

Abstract and Figures

Recommended publications

Permian paleogeography of west-central Pangea: Reconstruction using sabkha-type gypsum-bearing depos...

Permian dust in Oklahoma: Source and origin for Middle Permian (Flowerpot-Blaine) redbeds in Western...

Climatic and Palaeogeographic Significance of Aeolian Sediment in the Middle Permian Dog Creek Shale...

Tracing Clastic Delivery To the Permian Delaware Basin, U.S.A.: Implications For Paleogeography and...

The paleoclimatic and geochronologic utility of coring redbeds and evaporites: A case study from the...