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New Frontiers in Paleopedology and Terrestrial Paleoclimatology:
Paleosols and Soil Surface Analog Systems
Steven G. Driese and Lee C. Nordt, Editors
Paul J. McCarthy, Contributing Editor
CONTENTS
Introduction
New Frontiers in Paleopedology and Terrestrial Paleoclimatology: Paleosols and Soil Surface Analog Systems
STEVEN G. DRIESE AND LEE C. NORDT.................................................................................................................................. 1
Historical Perspective
A Short History and Long Future for Paleopedology
GREGORY J. RETALLACK.......................................................................................................................................................... 5
Lessons from Surface Soil Systems
Carbon Stable Isotope Composition of Modern Calcareous Soil Profiles in California: Implications for CO 2 Reconstructions from
Calcareous Paleosols
NEIL J. TABOR, TIMOTHY S. MYERS, ERIK GULBRANSON, CRAIG RASMUSSEN, AND NATHAN D. SHELDON .. 17
CO 2 Concentrations in Vertisols: Seasonal Variability and Shrink-Swell
DANIEL O. BREECKER, JUNYEON YOON, LAUREN A. MICHEL, TAKELE M. DINKA, STEVEN G. DRIESE, JASON S.
MINTZ, LEE C. NORDT, KATHERINE D. ROMANAK, AND CRISTINE L.S. MORGAN .................................................... 35
Groundwater-Fed Wetland Sediments and Paleosols: It’s All about Water Table
GAIL M. ASHLEY, DANIEL M. DEOCAMPO, JULIA KAHMANN-ROBINSON, AND STEVEN G. DRIESE.................... 47
Soil and Landscape Memory of Climate Change—How Sensitive, How Connected?
H. CURTIS MONGER AND DAVID M. RACHAL ..................................................................................................................... 63
From Soils to Paleosols
Using Paleosols to Understand Paleo-Carbon Burial
NATHAN D. SHELDON AND NEIL J. TABOR .......................................................................................................................... 71
Paleoclimatic Applications and Modern Process Studies of Pedogenic Siderite
GREG A. LUDVIGSON, LUIS A. GONZÁLEZ, DAVID A. FOWLE, JENNIFER A. ROBERTS, STEVEN G. DRIESE, MARK
A. VILLARREAL, JON J. SMITH, AND MARINA B. SUAREZ ............................................................................................... 79
Multianalytical Pedosystem Approach to Characterizing and Interpreting the Fossil Record of Soils
LEE C. NORDT, CHARLES T. HALLMARK, STEVEN G. DRIESE, AND STEPHEN I. DWORKIN.................................... 89

Relationship to Alluvial Stratigraphy and Depositional Systems
Alluvial Stacking Pattern Analysis and Sequence Stratigraphy: Concepts and Case Studies
STACY C. ATCHLEY, LEE C. NORDT, STEPHEN I. DWORKIN, DAVID M. CLEVELAND, JASON S. MINTZ, AND R.
HUNTER HARLOW.................................................................................................................................................................. 109
Prograding Distributive Fluvial Systems—Geomorphic Models and Ancient Examples
G.S. WEISSMANN, A.J. HARTLEY, L.A. SCUDERI, G.J. NICHOLS, S.K. DAVIDSON, A. OWEN, S.C. ATCHLEY, P.
BHATTACHARYYA, T. CHAKRABORTY, P. GHOSH, L.C. NORDT, L. MICHEL, AND N.J. TABOR ............................... 131
Soil Development on Modern Distributive Fluvial Systems: Preliminary Observations with Implications for Interpretation of
Paleosols in the Rock Record
ADRIAN J. HARTLEY, GARY S. WEISSMANN, PROMA BHATTACHARYYA, GARY J. NICHOLS, LOUIS A. SCUDERI,
STEPHANIE K. DAVIDSON, SOPHIE LELEU, TAPAN CHAKRABORTY, PARTHASARATHI GHOSH, AND ANNE E.
MATHER .................................................................................................................................................................................... 149
Case Studies of Ancient Soil Systems
A Pedostratigraphic Approach to Nonmarine Sequence Stratigraphy: A Three-Dimensional Paleosol-Landscape Model from the
Cretaceous (Cenomanian) Dunvegan Formation, Alberta and British Columbia, Canada
PAUL J. MCCARTHY AND A. GUY PLINT .............................................................................................................................. 159
Anatomy, Evolution, and Paleoenvironmental Interpretation of an Ancient Arctic Coastal Plain: Integrated Paleopedology and
Palynology from the Upper Cretaceous (Maastrichtian) Prince Creek Formation, North Slope, Alaska, USA
PETER P. FLAIG, PAUL J. MCCARTHY, AND ANTHONY R. FIORILLO ............................................................................. 179
Integrated Paleopedology and Palynology from Alluvial Paleosols of the Cretaceous (Cenomanian) Dunvegan Formation, Alberta
and British Columbia, Canada: Paleoenvironmental and Stratigraphic Implications
JACOB R. MONGRAIN, PAUL J. MCCARTHY, A. GUY PLINT, AND SARAH J. FOWELL ............................................... 231
Early Cambrian Humid, Tropical, Coastal Paleosols from Montana, USA
GREGORY J. RETALLACK...................................................................................................................................................... 257
Glossary
Glossary of Paleopedological Terms Used in Assembled Papers
PAUL J. MCCARTHY, LEE C. NORDT, AND STEVEN G. DRIESE ....................................................................................... 273

A SHORT HISTORY AND LONG FUTURE FOR PALEOPEDOLOGY
GREGORY J. RETALLACK
Department of Geological Sciences, University of Oregon, Eugene, Oregon 97302, USA
e-mail: gregr@uoregon.edu
ABSTRACT: The concept of paleosols dates back to the eighteenth century discovery of buried soils,
geological unconformities, and fossil forests, but the term paleopedology was first coined by Boris B.
Polynov in 1927. During the mid-twentieth century in the United States, paleopedology became mired in
debates about recognition of Quaternary paleosols, and in controversy over the red-bed problem. By the
1980s, a new generation of researchers envisaged red beds as sequences of paleosols and as important
archives of paleoenvironmental change. At about the same time, Precambrian geochemists began
sophisticated analyses of paleosols at major unconformities as a guide to the long history of atmospheric
oxidation. It is now widely acknowledged that evidence from paleosols can inform studies of stratigraphy,
sedimentology, paleoclimate, paleoecology, global change, and astrobiology. For the future, there is much
additional potential for what is here termed “nomopedology,” using pedotransfer functions derived from
past behavior of soils to predict global and local change in the future. Past greenhouse crises have been of
varied magnitude, and paleosols reveal both levels of atmospheric CO 2 and degree of concomitant
paleoclimatic change. Another future development is “astropedology”, completing a history of soils on
early Earth, on other planetary bodies such as the Moon and Mars, and within meteorites formed on
planetismals during the origin of the solar system.

CARBON STABLE ISOTOPE COMPOSITION OF MODERN CALCAREOUS
SOIL PROFILES IN CALIFORNIA: IMPLICATIONS FOR CO 2
RECONSTRUCTIONS FROM CALCAREOUS PALEOSOLS
NEIL J. TABOR AND TIMOTHY S. MYERS
Roy M. Huffington Department of Earth Sciences, Southern Methodist University, Dallas,
Texas 75275-0395, USA
e-mail: ntabor@smu.edu
ERIK GULBRANSON
Department of Geosciences, University of Wisconsin, Milwaukee, Wisconsin 53201, USA
CRAIG RASMUSSEN
Soil, Water and Environmental Science, University of Arizona, Tucson, Arizona 85721, USA
AND
NATHAN D. SHELDON
Department of Geological Sciences, University of Michigan, Ann Arbor,
Michigan 48105-1005, USA
ABSTRACT: Fourteen soil profiles from California were collected in order to measure the δ 13 C of
coexisting soil calcite and organic matter. Thirteen of the profiles contained a measurable amount of
calcite ranging from 0.04 to 54.6 wt %. Soil calcite δ 13 CPDB (δ 13 C value vs. the calcite standard Peedee
Belemnite) values range from -14.4 to 1.3‰, whereas organic matter δ 13 CPDB values range from -24.0 to -
27.7‰.
The hydrology of these profiles is divided into two broad groups: (1) soils characterized by gravitydriven,
piston-type vertical flow through the profile and (2) soils affected by groundwater within the
profile at depths where calcite is present. The difference between soil calcite and organic matter δ 13 CPDB
values, ∆ 13 C cc-om , is smaller in profiles affected by groundwater saturation as well as most Vertisols and
may be a product of waterlogging. The larger ∆ 13 C cc-om values in soils with gravity-driven flow are
consistent with open-system mixing of tropospheric CO 2 and CO 2 derived from in situ oxidation of soil
organic matter with mean soil PCO 2 values potentially in excess of ~20,000 ppmV at the time of calcite
crystallization. There is a correlation between estimates of soil PCO 2 and a value termed “E PPT-U ”
(kJm2/yr) among the soil profiles characterized by gravity-driven flow. E PPT-U is the energy flux through
the soil during periods of soil moisture utilization, and it is the product of water mass and temperature in
the profile during the growing season. Thus, soils with high water-holding capacity/storage and/or
low/high growing season temperature may form soil calcite in the presence of high soil PCO 2 , and vice
versa. The results of this research have important implications for reconstructions of paleoclimate from
stable carbon isotopes of calcareous paleosol profiles.

CO 2 CONCENTRATIONS IN VERTISOLS: SEASONAL VARIABILITY AND
SHRINK–SWELL
DANIEL O. BREECKER AND JUNYEON YOON
Department of Geological Sciences, The University of Texas at Austin, 1 University Station
C1100, Austin, Texas 78712, USA
e-mail: breecker@jsg.utexas.edu
LAUREN A. MICHEL
Department of Geology, Baylor University, One Bear Place #97354, Waco, Texas 76798, USA
TAKELE M. DINKA
Soil and Crop Sciences Department, Texas A&M University, 2474 TAMU, College Station,
Texas 77843, USA
STEVEN G. DRIESE, JASON S. MINTZ, AND LEE C. NORDT
Department of Geology, Baylor University, One Bear Place #97354, Waco, Texas 76798, USA
KATHERINE D. ROMANAK
Bureau of Economic Geology, The University of Texas at Austin, Austin, Texas 78712, USA
AND
CRISTINE L.S. MORGAN
Soil and Crop Sciences Department, Texas A&M University, 2474 TAMU, College Station,
Texas 77843, USA
ABSTRACT: The paleosol–carbonate CO 2 barometer is widely accepted to be the most reliable method
for reconstructing Earth’s atmospheric CO 2 concentrations in deep time. Currently, the largest source of
error in atmospheric CO 2 calculated using the paleosol barometer originates from uncertainty in soil CO 2
concentrations during soil carbonate formation. Many of the paleosols used for CO 2 reconstruction were
formed in clay-rich alluvium and have vertic properties, which may influence soil CO 2 .We hypothesized
that the cracking during drying of shrink–swell clays results in rapid CO 2 escape and low soil CO 2
concentrations. We tested our hypothesis by monitoring soil cracking and the concentration of CO 2 in the
pore spaces of surface Vertisols (the Houston Black and Heiden series fine, smectitic, thermic Udic
Haplusterts). Crack porosity of soils was estimated by measuring soil subsidence, and CO 2 was measured
in syringe samples collected from soil gas wells. During the period of study, pore-space CO 2
concentrations at ~1-m soil depth varied by two orders of magnitude, from 10% during water-saturated
conditions to

GROUNDWATER-FED WETLAND SEDIMENTS AND PALEOSOLS: IT’S
ALL ABOUT WATER TABLE
GAIL M. ASHLEY
Department of Earth and Planetary Sciences, Rutgers University, Piscataway,
New Jersey 08854, USA
e-mail: gmashley@rci.rutgers.edu
DANIEL M. DEOCAMPO
Department of Geosciences, Georgia State University, Atlanta, Georgia 30302, USA
JULIA KAHMANN-ROBINSON
Department of Geology, Baylor University, One Bear Place #97354, Waco, Texas 76798, USA
AND
STEVEN G. DRIESE
Department of Geology, Baylor University, One Bear Place #97354, Waco, TX 76798, USA
ABSTRACT: Wetlands are continental depositional environments and ecosystems that range between
ephemerally wet to fully aquatic habitats, and, thus, the character of a wetland soil is directly related to
the position of the water table over seasonal and longer timescales. The sediment and paleosol records of
wetlands are products of a unique setting that can be both exposed to the atmosphere and water-saturated
at the same time. Wetlands tend to occupy low-gradient portions of the landscape in places where the
phreatic zone is at least ephemerally exposed at the surface, and hydrophytic vegetation has an
opportunity to colonize. Groundwater-fed wetlands are an end member of a continuum of waterlogged
environments and are associated with localized groundwater discharge (GWD); e.g., springs and seeps
that can sustain permanent saturation. Research has tended to follow one of two parallel tracks:
sedimentology or pedology. An objective of this paper is to bring these two separate lines of inquiry
closer together. The signature of wetland pedogenesis includes redoximorphic features, enhanced
hydrolytic alteration or dissolution of soluble phases, and preservation of biotic indicators of wetland
habitats. Histosols (peats) and other hydric soils (indicated by gley color and reduced minerals like pyrite
and siderite) are common in sites with a permanently high water table and anaerobic conditions. Illuvial
clays, in contrast, record episodes in which wetlands dry out and drainage improves sufficiently for these
features to form. A case study from Holocene-age Loboi Swamp, Kenya, illustrates the importance of
integrating field observations and laboratory analyses. Wetland conditions were observed through thin
section micromorphology, mineralogy, bulk geochemistry, and macro- and microfossils. The record of
Loboi Swamp is characterized by the juxtaposition of features indicating episodes of soil saturation
alternating with those indicating desiccation. In order to extract the most information recorded in
groundwater-fed wetlands, soils and sediments should be studied as part of the larger spatial and climatic
frameworks in which they occur.

SOIL AND LANDSCAPE MEMORY OF CLIMATE CHANGE—HOW
SENSITIVE, HOW CONNECTED?
H. CURTIS MONGER
New Mexico State University, Department of Plant and Environmental Sciences, Las Cruces,
New Mexico, 88003
e-mail: cmonger@nmsu.edu
AND
DAVID M. RACHAL
New Mexico State University, Department of Plant and Environmental Sciences, Las Cruces,
New Mexico, 88003
ABSTRACT: Paleosols are important sources of information about climate change. They carry a
“memory” of past environments as features such as pedogenic carbonate, carbon isotopes, profile depth,
and degree of chemical weathering. Certain features, such as soil organic matter, are more rapidly
adjusting (i.e., sensitive) to climate change than are other features, such as mineralogy which are slowly
adjusting (i.e., resistant) to climate change, but have a longer memory. In addition, the landscape itself
carries a memory of climate change through features such as patterned ground, dune fields, glacial
moraines, and lake shorelines. As is the case for soils, some landscapes are more sensitive to climate
change than others, and provide better sedimentary and paleosol records. A semiarid grassland on a sand
sheet, for example, is more sensitive to climate change and will produce a better paleosol record than a
neighboring semiarid grassland on a low-gradient terrain of bedrock outcrop. Landscapes and soil profiles
are connected to each other, to the aboveground ecosystem, and to climate as a complex adaptive system.
A perturbation to the system can change vegetative cover, initiate erosion, and leave a record in paleosols
as both “soil memory” and “lithomemory” (i.e., sedimentary deposits vertically separated by paleosols).
A systematic examination of soil memory and lithomemory can be used as a prospecting tool for finding
paleosols with high resolution paleoclimatic records. Some of the best paleosol records are in landscapes
with erodible regolith and topographic relief, where soil memory develops during periods of landscape
stability and lithomemory develops during intervening periods of landscape instability when erosion and
sedimentation rates are highest.

USING PALEOSOLS TO UNDERSTAND PALEO-CARBON BURIAL
NATHAN D. SHELDON
Department of Earth and Environmental Sciences, 1100 N. University Avenue, University of
Michigan, Ann Arbor, Michigan 48109, USA
e-mail: nsheldon@umich.edu
AND
NEIL J. TABOR
Huffington Department of Earth Sciences, P O Box 750395, Southern Methodist University,
Dallas, Texas 75275, USA
ABSTRACT: It has long been understood that the primary control on atmospheric carbon dioxide levels
over geologic time (10 6 –10 7 years) is silicate weathering. Schematically, this relationship is given by the
“Urey Equation,” such as CaSiO 3 + CO 2 = CaCO 3 + SiO 2 , where the equation represents weathering
going from left to right and metamorphism going from right to left. The logic of the Urey Equation can be
inverted to look instead at the consumption (and therefore burial) of carbon due to weathering because,
for example, it requires 2 moles of CO 2 from all sources (diffusion, rainfall, in situ productivity) to
weather 1 mole of silicate Ca 2+ . Thus, by characterizing chemical losses during pedogenesis, it is possible
to determine the total CO 2 that was consumed during pedogenesis. With reasonable estimates of
formation time, the gross consumption can be reconfigured as a rate of carbon consumption. This
theoretical framework is applied to basalt-parented paleosols from the Picture Gorge Subgroup (Oregon)
that span the middle Miocene climatic optimum. The calculations indicate that CO 2 consumption is not
simply a function of soil formation time and that it is instead controlled by the atmospheric CO 2 level.
Benthic foraminiferal δ 13 C values also indicate a carbon burial event at this time that is consistent with the
paleosol carbon sequestration estimates. As atmospheric CO 2 declined toward the end of the middle
Miocene climatic optimum by a factor of three, CO 2 consumption by silicate weathering dropped by at
least 50%, indicating a strong relationship between the two, even on relatively short timescales (10 4 –10 5
years).

PALEOCLIMATIC APPLICATIONS AND MODERN PROCESS STUDIES OF
PEDOGENIC SIDERITE
GREG A. LUDVIGSON
Kansas Geological Survey, The University of Kansas, 1930 Constant Avenue, Lawrence,
Kansas 66047-3724, USA
e-mail: gludvigson@kgs.ku.edu
LUIS A. GONZÁLEZ, DAVID A. FOWLE, AND JENNIFER A. ROBERTS
Department of Geology, The University of Kansas, 1475 Jayhawk Boulevard, Room 120,
Lawrence, Kansas 66045-7594, USA
STEVEN G. DRIESE
Department of Geology, Baylor University, One Bear Place #97354, Waco,
Texas 76798-7354, USA
MARK A. VILLARREAL AND JON J. SMITH
Kansas Geological Survey, The University of Kansas, 1930 Constant Avenue, Lawrence, Kansas
66047-3724, USA
AND
MARINA B. SUAREZ
Department of Geological Sciences, University of Texas at San Antonio, 1 UTSA Circle,
San Antonio, Texas 78249, USA
ABSTRACT: Pedogenic siderite is a carbonate mineral that forms in the reducing groundwaters of poorly
drained soils and paleosols in zonal climatic belts with strongly positive precipitation–evaporation
balances. Microcrystalline and spherulitic forms of siderite are commonly recognized in
micromorphologic studies of hydromorphic paleosols. Ancient paleosol sphaerosiderites commonly occur
with diameters in excess of 1 mm, while modern pedogenic siderite crystal dimensions in excess of 100
µm are rare. Pedogenic siderites have been widely reported from Late Paleozoic, Mesozoic, and Cenozoic
paleosols. The carbon and oxygen isotopic compositions of pedogenic siderites have been widely used as
proxies for the oxygen isotopic composition of paleoprecipitation for their respective paleosols. Modern
process studies of historic pedogenic siderites are yielding a more refined understanding of the stable
isotopic systematics of low-temperature siderite. These works will lead to a future change in usage of
published siderite–water 18 O fractionation equations.

MULTIANALYTICAL PEDOSYSTEM APPROACH TO CHARACTERIZING
AND INTERPRETING THE FOSSIL RECORD OF SOILS
LEE C. NORDT
Department of Geology, Baylor University, One Bear Place #97354, Waco, Texas 76798, USA
e-mail: Lee_Nordt@baylor.edu
CHARLES T. HALLMARK
Department of Soil and Crop Sciences, Texas A&M University, 370 Olsen Blvd., College
Station, Texas 77843, USA
STEVEN G. DRIESE AND STEPHEN I. DWORKIN
Department of Geology, Baylor University, One Bear Place #97354, Waco, Texas 76798, USA
ABSTRACT: Interpretations of critical zones, past and present, are dependent on the comprehensive
characterization of morphological, physical, chemical, biological, and mineralogical properties of soils as
the biogeochemical mediator of Earth’s surface processes. The traditional approach of studying fossil
soils (paleosols), however, is modeled after methods developed during the advent of pedology in the early
20th century. Even though there have been remarkable advances in the development of analytical
procedures for modern soils (pedology), advancements in paleopedology have not proceeded past wholerock
geochemical characterization. Here, we develop multianalytical strategies combining traditional and
modern approaches to studying paleosols that include direct laboratory measurement, petrographic
analysis, and pedotransfer functions. In addition to standardizing the characterization of paleosols, doing
so will also contribute to more robust geoinformatic compilations and strengthen interpretations of soil
processes, soil taxonomic classification, edaphic controls, and climate conditions in the past. We applied
the multianalytical approach to a paleosol from the Late Triassic and demonstrate that it classifies as a
Vertisol based on slickensides identified in the field, sepic fabric in thin section, and high values for
variables such as total and fine clay content, coefficient of linear extensibility (COLE), smectite content,
and available water capacity (AWC). Reconstructed cation exchange capacity (CEC), pH, and base
saturation point to a plentiful supply of plant available nutrients. Most reconstructed properties appear to
have been reasonably preserved because of shallow burial depths and the formation of slowly permeable
claystones. Further testing of direct analytical techniques and the development of pedotransfer functions
beyond Vertisols are needed to improve the characterization of the full range of properties expected in the
fossil rock record of soils.

ALLUVIAL STACKING PATTERN ANALYSIS AND SEQUENCE
STRATIGRAPHY: CONCEPTS AND CASE STUDIES
STACY C. ATCHLEY, LEE C. NORDT, AND STEPHEN I. DWORKIN
Baylor University, Department of Geology, One Bear Place #97354, Waco,
Texas 76798-7354, USA
e-mail: stacy_atchley@baylor.edu
DAVID M. CLEVELAND
ExxonMobil Upstream Research Company, 3120 Buffalo Speedway, Room SW640, Houston,
Texas 77098, USA
JASON S. MINTZ
Anadarko Petroleum Corporation, 1201 Lake Robbins Drive, The Woodlands,
Texas 77380, USA
AND
R. HUNTER HARLOW
Kansas Geological Survey, 1930 Constant Avenue, Lawrence, Kansas 66047, USA
ABSTRACT: Modern sequence-stratigraphic theory has its foundation in the work of L.L. Sloss and
W.C. Krumbein (1940s–1960s) and several Exxon researchers (1970s–1990s). This work largely focuses
on the nature and origin of sedimentary cycles within marine stratal successions. More recently,
sequence-stratigraphic concepts have evolved to include the analysis of terrestrial strata. Historically, the
recognition of unconformity-bounded cyclic stratal units (such as sequences) has relied upon the
geometric relationships of strata (i.e., onlap, toplap, truncation, and downlap) within two- and/or threedimensional
outcrop or subsurface successions. Oftentimes, however, outcrops or boreholes are isolated
and do not preserve these diagnostic stratal relationships. In such instances, documentation of changes in
the vertical, rather than lateral, succession of strata may allow reconstruction of the cyclic accommodation
history and placement of associated bounding discontinuities. This technique, referred to as “stacking
pattern” analysis, was originally developed for shallow-marine carbonate successions. More recently, the
stacking pattern methodology has been similarly applied to alluvial successions and takes into account the
unique processes of terrestrial deposition and pedogenesis. The most conspicuous and fundamental cyclic
stratal units recognized within alluvial settings are fluvial aggradational cycles (FACs). Fluvial
aggradational cycles are meter-scale, typically fining-upward successions that have a disconformable
lower boundary and an upper boundary that either has a paleosol weathered into it or is disconformably
overlain by the succeeding FAC without a paleosol. Fluvial aggradational cycles are thought to represent
sediment accumulations during channel avulsion events that are subsequently weathered during the
following period of channel stability. A thick succession of FACs indicates sediment accumulation during
a prolonged episode of accommodation gain. Variations in the rate of accommodation gain (and loss) are
interpreted to result in the organization of FACs into alluvial sequences and longer period composite
sequences. Episodes of base-level rise result in relatively rapid rates of alluvial aggradation and less
developed and more poorly drained paleosols. Associated FACs are thicker than average and transition
from initially lower sinuosity, higher competence alluvial systems to comparably higher sinuosity, lower
competence channel deposits. As base-level rise decelerates and initially falls, paleosols become
increasingly well developed and better drained, and FACs are thinner than average and transition to even
lower competence, higher sinuosity channel sandstones that are more extensive as a result of prolonged
channel migration under low accommodation conditions. During base-level fall, the incisement of alluvial

valleys produces sequence boundaries that are infrequently flooded across interfluve areas. Fluvial
aggradational cycles across interfluve positions are much thinner than average and are characterized by
the most well-developed and best-drained paleosols.
Application of the alluvial stacking pattern methodology is demonstrated within three case studies. Case
study 1, from Big Bend National Park, Texas, considers a latest Cretaceous to earliest Tertiary passive
margin and coastal plain succession and correlates alluvial sequences and associated climate and
ecosystem changes to eustatic sea-level oscillations. Case study 2, from northern and northeastern New
Mexico, documents a Late Triassic foreland basin succession in which tectonically induced
accommodation events are correlated between isolated outcrop successions that are located 200 km apart.
Case study 3, from central New York, demonstrates how stacking pattern analysis allows correlation of a
Middle Devonian alluvial composite sequence with equivalent regressive–transgressive marine strata
along a convergent plate boundary.

PROGRADING DISTRIBUTIVE FLUVIAL SYSTEMS—GEOMORPHIC
MODELS AND ANCIENT EXAMPLES
G.S. WEISSMANN
Department of Earth and Planetary Sciences, MSC03 2040, 1 University of New Mexico,
Albuquerque, New Mexico 87131-0001, USA
e-mail: weissman@unm.edu
A.J. HARTLEY
Department of Geology & Petroleum Geology, School of Geosciences, University of Aberdeen,
Aberdeen AB24 3UE, UK
L.A. SCUDERI
Department of Earth and Planetary Sciences, MSC03 2040, 1 University of New Mexico,
Albuquerque, New Mexico 87131-0001, USA
G.J. NICHOLS
Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey TW20
0EX, UK
S.K. DAVIDSON
Department of Geology & Petroleum Geology, School of Geosciences, University of Aberdeen,
Aberdeen AB24 3UE, UK
A. OWEN
Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey TW20
0EX, UK
S.C. ATCHLEY
Baylor University, Department of Geology, One Bear Place #97354, Waco, Texas 76798, USA
P. BHATTACHARYYA
Department of Earth and Planetary Sciences, MSC03 2040, 1 University of New Mexico,
Albuquerque, New Mexico 87131-0001, USA
T. CHAKRABORTY AND P. GHOSH
Geological Studies Unit, Indian Statistical Institute, 203 B.T. Road, Kolkata, 700108, India
L.C. NORDT
Baylor University, Department of Geology, One Bear Place #97354, Waco, Texas 76798, USA
L. MICHEL AND N.J. TABOR
Huffington Department of Earth Sciences, Southern Methodist University, P.O. Box 750394,
Dallas, Texas 75275-0395, USA

ABSTRACT: Recent work indicates that most modern continental sedimentary basins are filled primarily
by distributive fluvial systems (DFS). In this article we use depositional environment interpretations
observed on Landsat imagery of DFS to infer the vertical succession of channel and overbank facies,
including paleosols, from a hypothetical prograding DFS. We also present rock record examples that
display successions that are consistent with this progradational model. Distal DFS facies commonly
consist of wetland and hydromorphic floodplain deposits that encase single channels. Medial deposits
show larger channel belt size and relatively well-drained soils, indicating a deeper water table. Proximal
deposits of DFS display larger channel belts that are amalgamated with limited or no soil development
across the apex of the DFS. The resulting vertical sedimentary succession from progradation will display
a general coarsening-upward succession of facies. Depending on climate in the sedimentary basin,
wetland and seasonally wet distal deposits may be overlain by well-drained medial DFS deposits, which
in turn are overlain by amalgamated channel belt deposits. Channel belt size may increase upward in the
section as the DFS fills its accommodation. Because the entry point of rivers into the sedimentary basin is
relatively fixed as long as the sedimentary basin remains at a stable position, the facies tracts do not shift
basinward wholesale. Instead, we hypothesize that as the DFS fills its accommodation, the
accommodation/sediment supply (A/S) ratio decreases, resulting in coarser sediment upward in the
section and a greater degree of channel belt amalgamation upward as a result of reworking of older
deposits on the DFS. An exception to this succession may occur if the river incises into its DFS, where
partial sediment bypass occurs with more proximal facies deposited basinward below an intersection
point for some period of time. Three rock record examples appear to be consistent with the hypothesized
prograding DFS signal. The Blue Mesa and Sonsela members of the Chinle Formation at Petrified Forest
National Park, Arizona; the Tidwell and Salt Wash members of the Morrison Formation in southeastern
Utah; and the Pennsylvanian–Permian Lodéve Basin deposits in southern France all display gleyed
paleosols and wetland deposits covered by better-drained paleosols, ultimately capped by amalgamated
channel belt sandstones. In the Morrison Formation succession, sediments that represent the medial
deposits appear to have been partially reworked and removed by the amalgamated channel belts that show
proximal facies, indicating that incomplete progradational successions may result from local A/S
conditions. The prograding DFS succession provides an alternative hypothesis to climate change for the
interpretation of paleosol distributions that show a drying upward succession.

SOIL DEVELOPMENT ON MODERN DISTRIBUTIVE FLUVIAL SYSTEMS:
PRELIMINARY OBSERVATIONS WITH IMPLICATIONS FOR
INTERPRETATION OF PALEOSOLS IN THE ROCK RECORD
ADRIAN J. HARTLEY
Department of Geology and Petroleum Geology, School of Geosciences, University of
Aberdeen, Aberdeen, AB24 3UE, UK
e-mail: a.hartley@abdn.ac.uk
GARY S. WEISSMANN AND PROMA BHATTACHARAYYA
Department of Earth and Planetary Sciences, University of New Mexico, MSC03 2040, 1
University of New Mexico, Albuquerque, New Mexico 87131-0001, USA
GARY J. NICHOLS
Department of Earth Sciences, Royal Holloway, University of London, Egham,
Surrey, TW20 0EX, UK
LOUIS A. SCUDERI
Department of Earth and Planetary Sciences, University of New Mexico, MSC03 2040, 1
University of New Mexico, Albuquerque, New Mexico 87131-0001, USA
STEPHANIE K. DAVIDSON AND SOPHIE LELEU*
Department of Geology and Petroleum Geology, School of Geosciences, University of
Aberdeen, Aberdeen, AB24 3UE, UK
*Present address: EA4592 G&E, ENSEGID, Institut Polytechnique de Bordeaux, 1 allée Daguin,
33 607 Pessac, France
TAPAN CHAKRABORTY AND PARTHASARATHI GHOSH
Indian Statistical Institute, 205 B.T. Road, Kolkata, India
AND
ANNE E. MATHER
School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus,
Plymouth, PL4 8AA, UK
ABSTRACT: Understanding of controls on the distribution of soils in modern sedimentary basins
facilitates interpretation of paleosols in the rock record. Here, we present information on soil distribution
from a number of modern distributive fluvial systems (DFSs) in sedimentary basins developed in
different climatic and tectonic settings. DFSs form an important part of modern alluvial sedimentary
basins, and an understanding of the controls on soil development in these settings should facilitate
interpretation of the alluvial rock record. The studied areas include: the Pilcomayo and Bermejo DFSs in
the Andean foreland of Argentina, the Tista DFS of the Himalayan foreland basin in northern India, and
the Okavango DFS developed in an intracontinental rift basin in Botswana. Soils in each of the examples
are relatively immature and weakly developed. Where present, downdip changes (over distances >100
km) from relatively well-drained, relatively dry soils in sandy proximal areas to more poorly drained,
relatively wet soils in more distal, clay-rich areas can be recognized. In the Andean example, this change

is considered to be related to a downdip increase in precipitation and decreasing depth to water table. In
the Himalayan system, this is considered to be due to a combination of decreasing depth to water table
and increased surface flooding due to direct, monsoon-driven precipitation on the DFS surface. An
increase in poorly drained soil development occurs near the toe of the DFS in Botswana, despite high
transmission losses across the system.
A key implication from these modern systems is that a change from well-drained to poorly drained soils is
controlled by hydrology. This change occurs along a single isochronous surface that may extend for
hundreds of kilometers and could be preserved in the rock record. Rock record examples that describe a
downdip change from well-drained to poorly drained soils have been documented previously and are
attributed to tectonic, climatic, autocyclic, and hydromorphic controls. Our studies from modern DFSs
would suggest that a hydromorphic control is likely to be the most important factor.
Criteria derived from modern DFSs for distinguishing between changes in soil type that record climate
change include the observation that paleosols developed in the proximal well-drained area are likely to be
associated with a sandy parent material and sand-dominated channel facies. In contrast, in the distal
DFSs, more poorly drained soils are likely to be developed on a silt- or clay-rich parent material
interbedded with a mixture of sandy and muddy meandering channel-fill deposits, crevasse splays, and
floodplain sands and muds. Paleosols that record climate change should show no discernible relationship
between parent material and soil type. While similar relationships between soil type and parent material
have been described previously, their distribution within the context of a DFS has not been widely
documented.

A PEDOSTRATIGRAPHIC APPROACH TO NONMARINE SEQUENCE
STRATIGRAPHY: A THREE-DIMENSIONAL PALEOSOL-LANDSCAPE
MODEL FROM THE CRETACEOUS (CENOMANIAN) DUNVEGAN
FORMATION, ALBERTA AND BRITISH COLUMBIA, CANADA
PAUL J. MCCARTHY
Department of Geology & Geophysics and Geophysical Institute, University of Alaska,
Fairbanks, Alaska 99775-5780
e-mail: pjmccarthy@alaska.edu
AND
A. GUY PLINT
Department of Earth Sciences, The University of Western Ontario, London, Ontario, N6A 5B7,
Canada
ABSTRACT: A basin-scale pedostratigraphic model that focuses on paleosols and their pedostratigraphic
relationships has been established for the Cenomanian Dunvegan Formation, a unit that represents a large
delta complex. A detailed sequence stratigraphic and paleogeographic framework permits analysis of
paleosol development with respect to distance from marine shorelines and coeval valleys. Paleosols that
bracket sequence boundaries vary depending upon their paleo-landscape position. The sequence-bounding
package of paleosols can be partitioned into three spatial zones based upon both the degree of
development and the architecture of the paleosols. Zone 1 occurs in seaward localities near the maximum
regressive shoreline and is characterized by hydromorphic, weakly developed paleosols typical of a
poorly drained, progradational, and aggradational coastal plain. Zone 2 occurs in an intermediate location
and is characterized by well-developed Alfisol-like welded paleosols that record a complex architecture
indicating (i) an aggradational phase; (ii) a subsequent static and/or degradational phase related to valley
incision, nondeposition, and soil thickening; and (iii) a final aggradational phase related to valley filling
and renewed sedimentation across the coastal plain. Zone 3 occurs in more up-dip settings and is
characterized by compound and complex Inceptisol-like paleosols that developed as the result of a
reduced aggradation rate when valleys were being incised further down-dip. Because accommodation,
sediment supply, and hydrological conditions vary in both dip and strike directions, the three zones
represent lateral soil facies equivalents. The soil-forming interval bracketing the sequence boundary
comprises a geosol composed of welded paleosols that subdivide both up-dip and down-dip into more
weakly developed aggradational paleosol complexes. Above the sequence boundary, a high
accommodation phase (equivalent to the Transgressive Systems Tract) is represented by widespread
lacustrine and poorly drained floodplain facies and weakly developed hydromorphic paleosols. As
accommodation rate decreases (late Highstand Systems Tract time) the alluvial succession becomes
paleosol dominated, comprising floodplain pedocomplexes that record a regional decrease in the
accommodation/sediment supply ratio. Up-dip variability along the sequence boundary and within
sequences is controlled primarily by variations in the accommodation/sediment supply ratio, by
hydrological variations associated with floodplain incision during valley formation, and by tectonic
subsidence rates that vary in space and in time.

ANATOMY, EVOLUTION, AND PALEOENVIRONMENTAL
INTERPRETATION OF AN ANCIENT ARCTIC COASTAL PLAIN:
INTEGRATED PALEOPEDOLOGY AND PALYNOLOGY FROM THE UPPER
CRETACEOUS (MAASTRICHTIAN) PRINCE CREEK FORMATION, NORTH
SLOPE, ALASKA, USA
PETER P. FLAIG
The University of Texas at Austin, Bureau of Economic Geology, Jackson School of
Geosciences, 10100 Burnett Road, Austin, Texas 78758, USA
e-mail: peter.flaig@beg.utexas.edu
PAUL J. MCCARTHY
Department of Geology and Geophysics, and Geophysical Institute, University of Alaska, P.O.
Box 755780, Fairbanks, Alaska 99775, USA
AND
ANTHONY R. FIORILLO
Perot Museum of Nature and Science, 2201 N. Field St., Dallas, Texas 75201, USA
ABSTRACT: The Cretaceous (Early Maastrichtian), dinosaur-bearing Prince Creek Formation (Fm.)
exposed along the Colville River in northern Alaska records high-latitude, alluvial sedimentation and soil
formation on a low-gradient, muddy coastal plain during a greenhouse phase in Earth history. We
combine sedimentology, paleopedology, palynology, and paleontology in order to reconstruct detailed
local paleoenvironments of an ancient Arctic coastal plain. The Prince Creek Fm. contains quartz- and
chert-rich sandstone and mudstone-filled trunk and distributary channels and floodplains composed of
organic-rich siltstone and mudstone, carbonaceous shale, coal, and ash-fall deposits. Compound and
cumulative, weakly developed soils formed on levees, point bars, crevasse splays, and along the margins
of floodplain lakes, ponds, and swamps. Abundant organic matter, carbonaceous root traces, Fe-oxide
depletion coatings, and zoned peds (soil aggregates with an outermost Fe-depleted zone, darker-colored
Fe-rich matrix, and lighter-colored Fe-poor center) indicate periodic waterlogging, anoxia, and gleying,
consistent with a high water table. In contrast, Fe-oxide mottles, ferruginous and manganiferous
segregations, bioturbation, and rare illuvial clay coatings indicate recurring oxidation and periodic drying
of some soils. Trampling of sediments by dinosaurs is common. A marine influence on pedogenesis in
distal coastal plain settings is indicated by jarosite mottles and halos surrounding rhizoliths and the
presence of pyrite and secondary gypsum. Floodplains were dynamic, and soil-forming processes were
repeatedly interrupted by alluviation, resulting in weakly developed soils similar tomodern aquic
subgroups of Entisols and Inceptisols and, in more distal locations, potential acid sulfate soils. Biota,
including peridinioid dinocysts, brackish and freshwater algae, fungal hyphae, fern and moss spores,
projectates, age-diagnostic Wodehouseia edmontonicola, hinterland bisaccate pollen, and pollen from
lowland trees, shrubs, and herbs record a diverse flora and indicate an Early Maastrichtian age for all
sediments in the study area. The assemblage also demonstrates that although all sediments are Early
Maastrichtian, strata become progressively younger from south to north.
A paleoenvironmental reconstruction integrating pedogenic processes and biota indicates that polar
woodlands with an angiosperm understory and dinosaurs flourished on this ancient Arctic coastal plain
that was influenced by seasonally(?) fluctuating water table levels and floods. In contrast to modern polar
environments, there is no evidence for periglacial conditions on the Cretaceous Arctic coastal plain, and

oth higher temperatures and an intensified hydrological cycle existed, although the polar light regime
was similar to that of the present. In the absence of evidence of cryogenic processes in paleosols, it would
be very difficult to determine a high-latitude setting for paleosol formation without independent evidence
for paleolatitude. Consequently, paleosols formed at high latitudes under greenhouse conditions, in the
absence of ground ice, are not likely to have unique pedogenic signatures.

INTEGRATED PALEOPEDOLOGY AND PALYNOLOGY FROM ALLUVIAL
PALEOSOLS OF THE CRETACEOUS (CENOMANIAN) DUNVEGAN
FORMATION, ALBERTA AND BRITISH COLUMBIA, CANADA:
PALEOENVIRONMENTAL AND STRATIGRAPHIC IMPLICATIONS
JACOB R. MONGRAIN* AND PAUL J. MCCARTHY
Department of Geology & Geophysics, and Geophysical Institute, University of Alaska,
Fairbanks, Alaska 99775-5780, USA
*Present address: Shell Exploration and Production Company, Houston,
Texas 77079-1115, USA
e-mail: Jacob.Mongrain@shell.com
A. GUY PLINT
Department of Earth Sciences, The University of Western Ontario, London,
Ontario, N6A 5B7, Canada
AND
SARAH J. FOWELL
Department of Geology & Geophysics, University of Alaska, Fairbanks,
Alaska 99775-5780, USA
ABSTRACT: The Dunvegan Formation is a mid-Cretaceous alluvial plain–deltaic deposit exposed along
the Rocky Mountain Foothills and Peace River Valley of Alberta and British Columbia, Canada. A
multiproxy approach, combining paleosol micromorphology, geochemistry, and mineralogy with
palynology, is used to reconstruct the climatic, pedogenic, and depositional history of this high-latitude
setting during a greenhouse climate regime. Intrinsic features of paleosols within the Dunvegan
Formation suggest a warm to cool temperate paleoclimate. These paleosols experienced multiple
depositional phases superimposed on pedogenic phases that resulted in complicated compound, complex,
and welded paleosol profiles. Well-preserved palynomorph assemblages within the paleosols are
composed primarily of fern spores, with small percentages of gymnosperm pollen. The palynomorphs
suggest a humid paleoclimate ranging from cool temperate to subtropical. The abundance of fern spores
in all of the paleosol profiles suggests early successional colonization of the floodplain. Better-developed
interfluve paleosols contain greater percentages of tree pollen, indicating the presence of nearby forests.
Within interfluve paleosols, intervals barren of pollen coincide with sequence boundaries identified on the
basis of micromorphology and geochemistry. Our combined paleopedological and palynological data sets,
together with macrofloral and geochemical paleoclimate indicators, suggest that the Dunvegan alluvial–
coastal plain complex probably formed under a humid, warm to cool temperate paleoclimate with a mean
annual temperature (MAT) between 12 and 14° C and mean annual precipitation (MAP) between 1200
and 1300 mm yr -1 . These integrated data sets also provide a better understanding of the stratigraphic
development of the coastal plains.

EARLY CAMBRIAN HUMID, TROPICAL, COASTAL PALEOSOLS FROM
MONTANA, USA
GREGORY J. RETALLACK
Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA
e-mail: gregr@uoregon.edu
ABSTRACT: A putative Precambrian paleosol mapped at the unconformity between the Cambrian
Flathead Sandstone and Belt Supergroup at Fishtrap Lake, Montana, was found instead to be a succession
of paleosols forming the basal portion of the Flathead Sandstone. Early Cambrian age of these paleosols
comes from stratigraphic ranges of associated marine trace fossils: Bergaueria hemispherica,
Didymaulichnus lyelli, Torrowangea sp. indet., and Manykodes pedum. Instead of a single strongly
developed paleosol on top of the Belt Supergroup with a smooth geochemical depth function, five
successive geochemical and petrographic spikes were interpreted as so many individual paleosols within a
short sedimentary sequence of red beds, overlying brecciated and little-weathered Belt Supergroup. The
most weathered intervals (paleosol A horizons) are purple–red in color (Munsell weak red, 7.5R 4/2) and
massive to hackly, whereas intervening marine siltstones are planar bedded and purple–gray (Munsell
dark reddish gray, 7.5R 4/1). The massive to hackly appearance comes from blocky to platy peds defined
by argillans and is also the result of pervasive bioturbation of two distinct kinds: drab-haloed filament
traces and ferruginized-organic filaments. In thin section, the filaments are circular as well as elliptical
and elongate and of presumed microbial origin. The filament-rich (A) horizons are also defined by
magnetic susceptibility and show petrographic evidence of significant weathering (depleted abundance of
rock fragments, feldspar, and mica compared with lower horizons). Additional evidence of weathering
comes from chemical analyses showing net loss of mass and weatherable elements within a profile. These
lines of evidence indicate that Montana estuarine landscapes during the earliest Cambrian were colonized
by filamentous organisms in a tropical humid paleoclimate, rather than the frigid conditions documented
elsewhere during the Late Ediacaran and Early Cambrian.