HIGH FREQUENCY SEQUENCE STRATIGRAPHIC CONTROLS ON STRATAL ARCHITECTURE OF AN UPPER PENNSYLVANIAN “REGRESSIVE LIMESTONE” (BETHANY FALLS LIMESTONE), MIDCONTINENT, USA
By
GRAHAM J. BUTLER, B.S.
A THESIS
IN
GEOSCIENCES
Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of
MASTER OF SCIENCE
Approved
Dr. Peter Holterhoff Chairperson of the Committee
Dr. James E. Barrick
Dr. George Asquith
Dr. Peggy Gordon Miller Interim Dean of the Graduate School
December, 2010
Copyright 2010, Graham James Butler All Rights Reserved Texas Tech University, Graham Butler, December 2010
ACKNOWLEDGEMENTS
I would like to thank Dr. Peter Holterhoff, Dr. Jim Barrick, and Dr. George
Asquith for standing on my committee and for being not only mentors but friends.
Special thanks are due to Dr. Steven Rosscoe for sacrificing many of his valuable weekends to share his expertise on Mid-Pennsylvanian conodonts. To the Texas Tech
Geosciences Department I would like to thank everyone for their assistance and specifically James Browning for his cutting of thin sections. Lastly, I would like to thank my friends, family, and fiancée for their endless support and assistance in every way possible. Without you all, it may never have been finished.
ii Texas Tech University, Graham Butler, December 2010
TABLE OF CONTENTS
ACKNOWLEDGEMENTS ii ABSTRACT vi LIST OF TABLES viii LIST OF FIGURES ix CHAPTER I. INTRODUCTION 1 II. BACKGROUND INFORMATION 4 2.1 The Cyclothem Model 4 2.2 Sequence Stratigraphy 8 2.2.1 The Falling Stage Systems Tract 12 2.2.2 Clarification of Common FSST Terms 15 2.3 Sequence Stratigraphy vs. the Cyclothem Model 17 2.4 Geologic Setting and Paleogeography 19 2.5 Previous Research 25 III. METHODOLOGY 29 3.1 Sampling 29 3.2 Sample Processing 30 3.3 Data Analysis 31 IV. LITHOFACIES AND MAJOR LITHOFACIES TYPES (MFT) 33
4.1 MFT – 01: Skeletal Mudstone Facies 35 4.1.1 Major Lithofacies Description: Skeletal Mudstone 37
4.2 MFT – 02: Skeletal Wackestone Facies 39 4.2.1 Major Lithofacies Description: Skeletal Wackestone 41
iii Texas Tech University, Graham Butler, December 2010
4.3 MFT – 03: Skeletal Packstone 42 4.3.1 Major Lithofacies Description: Skeletal Packstone 43
4.4 MFT – 04: Coated Grain Facies 44
4.4.1 MFT – 04a: Ooid Grainstone (porous) 44
4.4.2 MFT – 04b: Ooid Grainstone (tight) 48
4.4.3 MFT – 04c: Ooid Wackestone-Packstone 50
4.4.4 MFT – 04d: Peloid-Ooid Grainstone-Packstone (tight) 53 4.5 Major Lithofacies Description: Coated Grainstone Facies 55 4.5.1 Ooid Grainstone Subfacies (porous) Discussion 57 4.5.2 Ooid Grainstone Subfacies (tight) Discussion 58 4.5.3 Ooid Packstone-Wackestone Subfacies Discussion 58 4.5.4 Peloid-Ooid Grainstone-Packstone Subfacies Discussion 59
4.6 MFT – 04: Shale Facies 60 4.6.1 Major Lithofacies Description: Shale Facies 61 V. CONODONT PALEOCOLOGY AND DISTRIBUTION 63 5.1 Introduction 63 5.2 Conodont Environment Interpretation 64 5.3 Conodont Results 66
5.4 Conodont Discussion 68
VI. DISCUSSION 70 6.1 HFSB vs. SB 70 6.2 Flooding events vs. Galesburg Shale 72
iv Texas Tech University, Graham Butler, December 2010
VII. SYNTHESIS 73 REFERENCES 80 APPENDICES A. MEASURED SECTIONS 87 B. OUTCROP PHOTOS 103 C. RESEARCH PHOTOS 118 D. GPS COORDINATES OF OUTCROPS 122 E. CONODONT RAW DATA 124 F. CROSS SECTION I Back Pocket G. CROSS SECTION II Back Pocket
v Texas Tech University, Graham Butler, December 2010
ABSTRACT
The Early Missourian (Upper Pennsylvanian) Bethany Falls Limestone (BFL) is
the highstand–falling stage carbonate member of the Swope high frequency sequence as
developed on the northern platform of the Mid-continent Basin. It is underlain by the
condensed Hushpuckney Shale (maximum flooding surface) and is overlain by the
Galesburg Shale (lowstand of the Dennis sequence). The Swope sequence is a significant
hydrocarbon reservoir in the subsurface of western Kansas with outcrops of excellent
reservoir analog lithofacies exposed in eastern Kansas and adjacent states. Although the
BFL is often considered a uniform shallowing-upward carbonate system, we hypothesize
that traceable flooding and erosion surfaces can be recognized within the BFL and that these surfaces define basinward–stepping carbonate clinothems. Recognizing this internal
architecture is critical for understanding the potential controls on the deposition and
diagenesis of oolite facies developed across the region within the BFL.
Flooding surfaces within the BFL are recognized by mudrock (clay-rich shale)
partings throughout the carbonate succession. Distinctive conodont biofacies collected
from these mudrocks aid in correlation and provide some confidence in mapping these
surfaces across the region, although not without some ambiguity. Correlations indicate
that basinward stepping clinothem packages can be recognized within the BFL.
Conodont abundances and species occurrences also aid in the determination of the
depositional environments of the flooding surfaces. Proximal occurrences of the mudrock
partings contain a lower abundance, lower diversity fauna compared to more distal
locations along a clinoform profile. Unexpected faunas with the presence of “deepwater”
vi Texas Tech University, Graham Butler, December 2010
genera and high overall abundances in the lower BFL are noted at some locations. These
occurrences appear to coincide with structural highs and may represent transitional facies
with the underlying condensed horizon.
Distinctive lithofacies offsets and internal exposure surfaces indicate the presence
of high frequency sequence boundaries within the BFL. These offsets are mappable and,
like the flooding surfaces, define clinothem packages. The distribution of carbonate
lithologies within these stratal packages is consistent with basinward progradation of
facies throughout clinothem deposition. Using this combined knowledge it is possible to identify high frequency sequence boundaries (HFSB) within this forced regressive package.
vii Texas Tech University, Graham Butler, December 2010
LIST OF TABLES
1 Research Localities' GPS Coordinates 123
2 Conodont Count Numbers (Raw Data) 125
viii Texas Tech University, Graham Butler, December 2010
LIST OF FIGURES
1.1 Stratigraphic Column of the Kansas Missourian Stage (Late Pensylvanian) (Wilke, 2000; after Miller, 1966). 3 1.2 Relationship of current continents to Pennsylvanian Midcontinent paleogeography, landmasses, and oceans (Scotese, 2002). 3
2.1.1 Ideal Kansas Cyclothem with sea-level curve (Heckel, 1986). 4
2.2.1 Chronostratigraphic vs lithostratigraphic (“layer-cake”) correlation methods. (Bashore et al., 1994). 9
2.2.2 Depositional sequence model displaying parasequences and systems tracts. (French, 1993). 9
2.2.3 Diagrams displaying aggradational and progradational clinoform packages. (Emery, 1999). 11
2.2.4 Diagram displaying the Falling Stage Systems Tract. 13
2.4.1 Close up of Midcontinent during Missourian continental flooding (Blakely, 2005). 20
2.4.2 NE Kansas and surrounding states overlaid with facies belts. (Modified after Heckel, 1978). 22
2.4.3 Base map showing outcrop localities with major regional features (Modified after Lee, 2005). Refer to Appendix V for GPS coordinates. 24
4.0.1 Typical Pennsylvanian cyclothem stratigraphy with sea level and environmental associations (Heckel, 1999). 33
4.02 Depositional facies model of Pennsylvanian low angle ramp geometries with ooid shoals. (Markello, 2008). 34
4.03 Thin section image of skeletal mudstone facies LC-KS-B4 sampled from bed four the 17mi S. of Louisburg KS outcrop. Note large brachiopod fragment. (Scale bar = 500um). 35
4.04 Polished Slab of skeletal mudstone sample LC-KS-B4. 36
ix Texas Tech University, Graham Butler, December 2010
4.05 Thin section of skeletal mudstone sample U-MO-10b collected from the base of bed 10 at the Utica, Mo outcrop. (Scale bar = 500um) 36
4.06 Cut and polished hand sample of skeletal mudstone collected from bed 10 at Utica, Mo (U-MO-B10). (Scale bar = 500um) 37
4.07 Thin section of skeletal wackestone sample LC-KS-B3-lwr collected from lower bed 3 at the outcrop 17mi S. of Louisburg, KS. Note brachiopod spine at top and ostracod near bottom. (Scale bar = 500um). 39
4.08 Hand sample of skeletal wackestone LC-KS-B3-lwr collected from the lower bed 3 at the 17mi S. of Louisburg, KS outcrop. Note the burrow-mottled fabric. 40
4.09 Thin section of skeletal wackestone sample #U-MO-B5 collected from bed 5 at the Utica, MO outcrop. Note: the fossil constituent is a brachiopod spine. (Scale bar = 500um). 40
4.10 Thin section of a brachiopod-dominated skeletal packstone collected from bed 9 at the Utica, MO outcrop (U-MO-B9). (Scale bar = 500um). 42
4.11 Cut and polished skeletal packstone slab from bed 9 Utica, MO outcrop (U-MO-B9). 43
4.12 Thin section of porous ooid-grainstone unit at Xenia, NW locality sample # XNW02. The blue epoxy = porosity. (Scale bar = 500um). 45
4.13 Cut and polished handsample of XNW02. Note bedding and porosity visible as shadows. 45
4.14 Thin section from the base of the upper ooid package at Jingo, KS. Sample # Jingo_base-top02 with porosity highlighted by blue epoxy. (Scale bar = 500um). 46
4.15 Handsample cut and polished from the lower portion of the upper ooid unit at Jingo, KS. Note the dead oil in the lower (black) portion of the handsample. 47
x Texas Tech University, Graham Butler, December 2010
4.16 Thin section from the uppermost ooid package from within a few inches of the sequence boundary. All ooids from within sample U- MO-TOPb are completely replaced with calcite contain no porosity. (Scale bar = 500um). 48
4.17 Polished handsample of the slab cut for thin section U-MO-TOP. 49
4.18 Photograph of reverse side of U-MO-TOP hand sample to show filled root casts. 49
4.19 Thin section of XNW-02 showing well preserved ooids and the minimal oomoldic porosity in a ooid wackestone-packstone. (Scale bar = 500um). 50
4.20 Close up of ooid wackestone-packstone XNW-01a showing ooid preservation. (Scale bar = 500um). 51
4.21 Thin section ooid wackestone-packstone XNW-01a with porosity filled with calcite cement and dead oil. (Scale bar = 500um). 51
4.22 Polished slab of ooid wackestone-packstone XNW-01a sample. Note styolites at top of specimen. 52
4.23 Thin section of peloid-ooid grainstone sample LC-KS-BF-top collected from the top grainstone unit at the 17mi south of Louisburg outcrop. (Scale bar = 500um). 53
4.24 Polished slab of sample LC-KS-BF-top collected from the top grainstone unit at the 17mi south of Louisburg outcrop. 54
4.25 Limestone fragments and larger fossil debris collected from shale parting FV-Rd-6 and caught in a 120 sieve after acid treatment. 60
4.26 Insoluble limestone fragments and fossil debris collected from shale parting Jingo S5 and collected in a 230 sieve post acid treatment. 61
5.1.1 Diagram of individual conodont elements (Armstrong and Brasier, 2005). 63
5.1.2 Water depth model with associated conodont depth environments (Heckel, 1994). 64
xi Texas Tech University, Graham Butler, December 2010
7.1 Time relationships within a basinward prograding platform system during relative sea-level regression. 75
A.1 Measured Section Key 88
A.2 Winterset, Iowa Measured Section 89
A.3 Utica, Missouri Measured Section 90
A.4 KY Rd and Hwy 291, Independence, Missouri Measured Section 91
A.5 63rd St. and I-435, Kansas City, Missouri Measured Section 92
A.6 Fireman’s Memorial, Kansas City, Missouri Measured Section 93
A.7 Bannister Rd., Kansas City, Missouri Measured Section 94
A.8 View High Dr., Kansas City, Missouri Measured Section 95
A.9 MO Hwy 2, Missouri Measured Section 96
A.10 Jingo Rd and Hwy 69, Kansas Measured Section 97
A.11 17 mi S. of Louisburg, Kansas Measured Section 98
A.12 Farlinville Roadcut, Kansas Measured Section 99
A.13 Mound City, Kansas Measured Section 100
A.14 Xenia NW, Kansas Measured Section 101
A.15 Bronson Quarry, Kansas Measured Section 102
B.1 Outcrop at Winterset, IA. Bethany Falls shown underlain by the dark black Hushpuckney shale. Scale at center is 72in divided into 12in increments. 104
B.2 Outcrop at Utica, MO. Bethany Falls shown underlain by the dark black Hushpuckney shale. Scale at center, centered on lower contact, is approximately 18in in height. 105
B.3 Outcrop at Hwy 291 and KY Rd Independence, MO. Bethany Falls shown, contact with Hushpuckney shale covered by talus, and contact with Galesburg shale forming recess at top of first ledge. 106
xii Texas Tech University, Graham Butler, December 2010
B.4 Outcrop at 435 and 63rd St. KC, MO. Dominant wackestone facies shown at center. Mottling is visible above scale. Bethany Falls shown, contact with Hushpuckney shale within drainage below geologist, and contact with Galesburg shale just above top of photograph. Scale = 1 meter 107
B.5 Outcrop at Fireman’s Memorial, KC, MO. Bethany Falls shown, underlain by the Hushpuckney shale, Elm Branch shale, and the Hertha Limestone. The Galesburg shale, which forms the recess above the Bethany Falls, and the Winterset are exposed above. Scale at bottom right = 1 meter. 108
B.6 Outcrop at Bannister Rd. and Blue River Rd., KC, MO. Bethany Falls shown, underlain by the Hushpuckney shale, with the contact covered by talus. The Galesburg shale forms the recess above the Bethany Falls at the top of the photograph. The limestone seen above, which is exposed in full, is the Winterset limestone. Scale at bottom left = 1 meter. 109
B.7 Outcrop at View High Dr., KC, MO. Bethany Falls shown, contact with underlying Hushpuckney Shale and approximately 2- 3 meters of Bethany Falls limestone is covered, top is marked by recess (at top of hammer). Scale at top right (hammer) = ~18in 110
B.8 Outcrop at Hwy 2, MO. Bethany Falls shown, contact with underlying Hushpuckney Shale is located at base of outcrop, and the top is marked by the recess. The Galesburg shale and Winterset limestone are both exposed above. Scale at bottom right = 1 meter 111
B.9 Outcrop at Hwy 69 and 383st (Jingo), Kansas. Bethany Falls shown, contact with underlying Hushpuckney Shale is located at base of resistant limestone ledge, and the top is marked by the sloping Galesburg shale. The Galesburg shale and Winterset limestone are both exposed above. Scale is approximately 1in = 1 meter 112
B.10 Outcrop on Hwy 69 17mi S. of Louisburg, Kansas. Bethany Falls shown, contact with underlying Hushpuckney Shale is not exposed, and the top is located at the top of the outcrop. Scale at bottom left = 72in 113
xiii Texas Tech University, Graham Butler, December 2010
B.11 Farlinville, Kansas outcrop. Bethany Falls shown, contact with underlying Hushpuckney Shale is located just below where subject is standing, and the top is located at the top of the outcrop. Scale: human = 74in 114
B.12 Outcrop just southwest of Mound City, Kansas. Bethany Falls shown, contact with underlying Hushpuckney Shale is located beneath talus at base of photograph, and the top is located at the top of the outcrop. Scale at right = 1 meter. 115
B.13 Xenia North West (XNW) Outcrop, Kansas. Bethany Falls shown, contact with Hushpuckney shale at pink box, and top of Bethany Falls located at recess at top of photograph. Pink box for scale = 30cm 116
B.14 Bronson Quarry outcrop, Kansas. Bethany Falls shown, contact with underlying Hushpuckney shale at base of quarry (obscured by talus), and top of Bethany Falls located at top ledge. Scale = 1 meter 117
C.1 Photo of weathered, mottled, "peanut", zone at 17mi S. Louisburg outcrop. Scale increments = 25cm. 119
C.2 Close up photo of weathered, mottled, "peanut", zone at View High Dr. outcrop. 119
C.3 Close up of unweathered, mottled, "peanut", zone at Bronson Quarry outcrop. Lens cap = approx. 7.2cm. 120
C.4 Photo of unweathered, mottled, "peanut", zone at Hwy 291 and KY Rd. outcrop. Geologist = approx. 183cm. 120
C.5 Ooid filled scour at top of MO. HWY 2 outcrop. Note crossbedding within ooid package at top left. Ooids scouring into mottled wackestone facies. Scale = 10cm increments. 121
C.6 Figure C.6: Alternating shales and limestones at base of Hwy 435 & 63rd St. outcrop (Figure. A.4). Scale = 10cm increments. 121
xiv Texas Tech University, Graham Butler, December 2010
CHAPTER I
INTRODUCTION
The Bethany Falls Limestone (BFL) member of the Swope Formation is part of a
Late Pennsylvanian (Missourian Stage, Kansas City Group, and Bronson Subgroup; Fig.
1.1) low-angle ramp carbonate system. During this time Pangea was in the final stages of
forming a large super continent (Fig. 1.2), the Mid-continent was a shallow sea centrally
located in the northern sub-tropics (5 – 10°N; Heckel, 1977; Scotese et al., 1993), and
eustatic sea-level change was controlled by the glaciation cycles of Gondwana (Soreghan
et al., 1999). Eustatic sea level of these cycles varied from 30 – 200m (Heckel, 1978,
Read, 1995; Rankey et al., 1999). It was this variation in sea level that controlled the
alternating deposition of carbonate and siliciclastic rock units (Felton et al., 1996) and
caused the highstand shoreline to shift northward, at times located in the vicinity of the
present day Canadian border (Heckel, 1996). As sea level transitioned into lowstand, the
shoreline migrated southward into Kansas (Heckel, 1980, Wilke, 2000). These variations
forced different lithologies to be deposited across the Mid-continent throughout the
glacial eustatic cycle.
The BFL is exposed across hundreds of miles through the present day Mid-
continent (North America). Due to the number of outcrops, their accessibility,
preservation, and spatial distribution, this formation provides an excellent opportunity for
detailed research of low angle-ramp architecture. In addition to the identifying and
mapping low angle architecture, these outcrops provide the ability to map smaller order
fluctuations and flooding intervals. This allows a rare glimpse of the shelf architecture
1 Texas Tech University, Graham Butler, December 2010
and of sea-level change, which is mappable across hundreds of miles, without access to
cores. Historically these strata have been described in a cyclothem-based system (ex.
Watney, 1989), although to properly explain the smaller scale changes a sequence-
stratigraphic system is necessary (ex. Heckel, 1994). Before the primary focus of this
study is explored, these strata will be identified independently in both a cyclothem and
sequence stratigraphic framework before any further discussion can continue.
This study, in addition to mapping the ramp architecture, addresses several issues
with the BFL: (1) Identify stacking patterns in outcrops. (2) Identify depositional
environments within the outcrops and examine lithofacies and lithofacies associations.
(3) Locate, collect, and do a detailed conodont analysis of shale partings/breaks. (4)
Place the BFL within a sequence stratigraphic-bounded framework identifying possible
5th-order sequences.
The ability to identify and correlate shale partings, which indicate both minor and
intermediate cyclicity, “provide for increased resolution in the refinement of the
Pennsylvanian sea-level curve” (Heckel, 1989; Boardman and Heckel, 1989). As well as
contributing to the Pennsylvanian sea level curve, the correlation and biostratigraphic
data retrieved through these investigations could increase the resolution of interbasinal
correlation. (Felton and Heckel, 1996)
2 Texas Tech University, Graham Butler, December 2010
Figure 1.1: Stratigraphic Column of a small part of the Kansas Missourian Stage (Late Pensylvanian) (Wilke, 2000, after Miller, 1966).
Figure 1.2: Relationship of current continents to Pennsylvanian Midcontinent paleogeography, landmasses, and oceans (Scotese, 2002).
3 Texas Tech University, Graham Butler, December 2010
CHAPTER II
BACKGROUND INFORMATION
2.1 The Cyclothem Model
Cyclothems, by definition, are “allostratigraphic units that are transgressive- regressive stratigraphic sequences resulting from a glacial eustatic rise and fall of sea level” (Heckel, 2002). This succession of strata is broken down into units that were
deposited throughout a glacial-eustatic cycle. A full glacial cycle (lowstand glacial to highstand interglacial back to glacial lowstand of sea level) contains four “ideal” members: outside shale, middle limestone, core shale, and upper limestone (Felton et al.,
1996). These four units comprise the “Ideal Kansas Cyclothem” (ex. Heckel, 1978) (Fig.
2.1.1).
Figure 2.1.1: Ideal Kansas Cyclothem with sea-level curve (Heckel, 1986)
4 Texas Tech University, Graham Butler, December 2010
Nearshore Shale – The outside shales are named for the “dominance of shale
formations that lie “outside” the “bundle” of limestones and thin shales that constitute the limestone formations” (Heckel, 1978). The outside shale units, which are dominated by nearshore marine and coastal plain siliciclastics and paleosols (Joeckel, 1999), are characteristically sandy and often are greater than 15m thick, with some localities
exceeding 30m. Due to their nearshore nature they contain minimal marine fauna, and in
turn, predominantly demonstrate nonmarine features such as coals, underclays, well
preserved land plant fossils, and in some places channel sandstones (Heckel, 1978).
Since nearshore shales are controlled by detrital sediment from riverine sources,
they form deltas with lobes prograding basinward. Variable thickness of the outside
shale can be seen from different localities due to delta lobe switching and the variance in sediment supply. Subaerial exposure, characterized by nonmarine deposits, signifies a deltaic plain whereas marine deposits with typically low diversity and sparse occurrences of organisms are prodelta to delta-front environments. These marine delta environments occur “where rapid deposition, increased turbidity, and fluctuating salinity reduced the abundance and diversity of marine organisms” (Heckel, 1978).
The nearshore shales thin northward, some containing a higher fossil content and diversity, whereas others display evidence of long-term exposure. This exposure is reddish in color due to oxidation and dehydration of the iron in the sediment (Heckel,
1978). To the south, into Oklahoma, the nearshore shales thicken greatly due to the greater detrital source in Oklahoma.
5 Texas Tech University, Graham Butler, December 2010
Transgressive Limestones – Located between the outside shale and the core shale,
hence the name “middle” limestone, trangressive limestone is a thin, typically 30cm-
150cm, ledge-forming, dense limestone. The biota from these limestones are diverse and
abundant including algae, indicating normal, open marine conditions. Fossils are present
although “do not seem abundant on outcrop because of the denseness of the rock”
(Heckel, 1978). Due to the abundance of algae and carbonates, deposition occurred
above the base of the photic zone, although with fine grain size and the large diversity of
marine species, the environment of deposition (EOD) was likely open marine and below
wave base.
As opposed to the nearshore shale, which varies in thickness, the transgressive limestone represents a large-scale shallow marine period for the Midcontinent, and is
laterally continuous for hundreds of miles along strike with little variance in thickness.
Any thickness variance is due to structural differences and topography of the older shales.
Offshore / Core Shales – Representing the deepest EOD, the offshore shales were
deposited well below the photic zone under dysoxic to anoxic conditions. These shales
were coined “core” shales by Heckel and Baesemann (1975) due to “their central position
within the megacyclothem” between the middle and upper limestones. They are
relatively thin and vary in thickness between about 0.5 meters and 2.0 meters. Like the
middle limestone, deposited just prior to the offshore shale, these shales vary little in
thickness laterally north to south. Since they were deposited in a dysoxic to anoxic
environment they are primarly composed of black fissile shale; phosphate nodules and
laminae (non skeletal) are common (Algeo and Heckel, 2008). The primary fossil
6 Texas Tech University, Graham Butler, December 2010
constituents are conodonts, on the order of thousands per kg, although fairly high
abundances of fish remains and phosphatic brachiopods are common. Above these black
fissile facies there is a less-fissile clay shale which is grey in color. Aside from being less
fissile, this shale contains a slightly higher skeletal count than the fissile shale, but
continue to have the phosphate nodules (Heckel, 1978).
Evidence points towards deposition over a long period of time on a drowned
platform away from the reaches of detrital sediment. This is also supported by the
presence of non-skeletal phosphorite, the small grain size of detrital sediment present,
and the very large abundance of conodonts. The dysoxic to anoxic conditions necessary
to form this shale would have required the formation of a “thermocline above the bottom
[to] prevent replenishment of bottom oxygen by vertical circulation” (Heckel, 1978;
Algeo and Heckel, 2008). With a thermocline in place to restrict vertical mixing,
plankton and other marine organisms settle below the thermocline, aiding in the removal
of oxygen from an already oxygen-starved environment. With these deposits of organic
matter and phosphorite, an ideal environment for black, fissile, phosphatic rich shale was
created.
Regressive Limestone – The fourth member of the ideal Kansas cyclothem is the
regressive limestone. This member is not as laterally consistent in thickness and usually
measures over 6m, although some Kansas regressive limestone packages extend over 9m
in thickness.
The base of these packages usually comprises a wavy bedded limestone deposited
below the wave base and, due to the rarity of algal material, below the euphotic zone.
7 Texas Tech University, Graham Butler, December 2010
Above this is usually found a skeletal, somewhat algal, limestone which sometimes
contains micrite grains and cross-bedding. This limestone probably formed within the
lower depth limits for algal growth and within the wave base. This is referred to as the
open marine facies (Heckel, 1978). Depending on which cyclothem is being examined,
the carbonate facies can vary since all regressive limestones do not shallow to the same
extent. Some do not shallow past the shallow-marine facies whereas others, such as the
Bethany Falls, shallow upwards into ooid shoal or tidal flat facies.
Further north, into Nebraska and Iowa, most regressive packages shallow upwards
into a tidal flat facies represented by generally unfossiliferous limestones with mudcracks
present. To the south the “regressive limestones thicken as they grade upward into
phylloid algal mound facies” (Heckel and Cocke, 1969) that consist of large bladed red
and green algal-dominated limestones.
2.2 Sequence Stratigraphy
Seismic stratigraphy, which was outlined in the AAPG Memoir 26, known
colloquially as “The Exxon Papers”, outlines the framework for the modern day concept
of sequence stratigraphy (Mitchum et al., 1977). This concept, although refined and
enhanced, has remained unchanged since its inception as a “stratigraphic unit composed
of genetically related strata bounded at its top and base by unconformities or their
correlative conformities” (Mitchum et al., 1977). The main advantage that was gained
from the introduction of sequence stratigraphy, as opposed to other methods of
correlation (for example lithostratigraphy, Fig. 2.2.1), is that sequence stratigraphic
8 Texas Tech University, Graham Butler, December 2010
boundaries are chronostratigraphically significant surfaces (Van Wagoner et al., 1990).
Whether it is drawn on a cross section or a seismic section, a Sequence Boundary (SB) is a traceable unconformity that separates older strata below from younger strata above
(Fig. 2.2.2).
Figure 2.2.1: Chronostratigraphic vs lithostratigraphic (“layer-cake”) correlation methods. (Bashore et al., 1994).
Figure 2.2.2: Depositional sequence model displaying parasequences and systems tracts. (French, 1993).
9 Texas Tech University, Graham Butler, December 2010
Classically, sequence stratigraphy divides strata into a framework of systems
tracts which together compose a sequence (Van Wagoner et al., 1988; Posamentier et al.,
1988). Through the progression of a sequence, as relative sea level transitions from
shallow water to deep water and then from deep to shallow, a series of lithologies is
deposited that reflects this change and is bounded at the top by the unconformity that
defines a sequence boundary. When relative sea level is at its lowest point within the
sequence, the lowstand systems tract (LST) is deposited. The LST is found only
basinward and below the relict shelf margin of the underlying sequence’s HST or in
incised valley fills on the platform itself. This LST is bounded at its base by a sequence
boundary (SB) and at the top by a transgressive surface (TS). The TS is the flooding
surface representing when relative sea level began to rise and extend across the platform
beyond the lapout of the LST onto the relict shelf margin of the underlying sequence. It is
the surface upon which the transgressive sequence tract (TST) is deposited. The TST
deepens upwards and is bounded at the top by the maximum flooding surface (MFS).
This is the surface at which relative sea level was at its highest. At this point, the
Highstand Systems Tract (HST) begins to be deposited as sedimentation rates overcome
relative sea level rise allowing sediments to aggrade. As the HST aggrades (Fig 2.2.3) it
eventually exceeds the global rise in sea level and begins to prograde (Fig. 2.2.3)
basinward. As this progradation occurs the sediment is deposited in the form of
parasequences (Fig. 2.2.2). It is these parasequences and parasequence sets that are the
building blocks of a sequence (Van Wagoner et al., 1990). A parasequence by definition
is a “relatively conformable, genetically related succession of beds or bedsets bounded by
marine-flooding surfaces or their correlative surfaces (Van Wagoner et al., 1988). As sea
10 Texas Tech University, Graham Butler, December 2010
level transitions during the HST, from rising, to static, and eventually to falling, the
parasequences transition from aggrading to prograding basinward. While prograding basinward it is possible for the parasequence deposits to down-step as sea level forces deposits basinward during the falling stage systems tract which will be discussed in the
upcoming section.
Figure 2.2.3: Diagrams displaying aggradational and progradational clinoform packages. (Emery, 1999).
11 Texas Tech University, Graham Butler, December 2010
2.2.1 The Falling Stage Systems Tract
The main issue with the initial definition of Sequence Stratigraphy was the lack of
recognition of a systems tract for the relative sea level transition from Highstand (HST) deposits to Lowstand (LST) deposits. There was definition of the Transgressive Systems
Tract (TST), which represents the retrogradational deposits between the LST and the
HST in a sea-level rise, but nothing comparable for the drop in sea-level (Van Wagoner et al., 1990). It has been hypothesized that the reason for this discrepancy “was due to the fact that it is commonly difficult to recognize offlapping strata in seismic sections
(because of subsequent regressive or transgressive erosional modification, or because it is below seismic resolution)” (Plint et al., 2000). First coined by Nummendal et al., (1992) the deposits were called the Falling Stage Systems Tract (FSST) (Fig. 2.2.4). The Falling
Stage Systems Tract is defined by a number of criteria outlined by Plint & Nummedal
(2000). These criteria state that the FSST must meet the following requirements: 1) that the FSST is defined by offlap where successively younger strata extend less shoreward and stratally terminate; 2) the systems tract is placed below the LST of the next sequence and above the HST of the current sequence; 3) if a stacking pattern is identifiable it contains higher frequency sequences punctuated by HFSB; and 4) that the FSST is deposited during a period of relative sea-level fall.
12 Texas Tech University, Graham Butler, December 2010
Figure 2.2.4: Diagram displaying the Falling Stage Systems Tract.
Although strictly defined in numerous papers (eg. Plint and Nummedal, 2000), the
falling stage systems tract is defined by offlap as well as a facies shift basinward.
Encompassing what had often been considered the upper portion of the highstand systems
tract, it is deposited during a drop in apparent sea level with the migration of marine
facies tracts basinward of the underlying parasequence. With this new definition, the
HST ends at the highest position of the shelf margin or ramp crest, which coincides with
the pinnacle of apparent sea level highstand. The lowstand systems tract occurs as the
point of lowest apparent sea level, which is also defined as the point of maximum
subaerial exposure on the platform. The lowest FSST boundary, in nearshore regions, is
the “stratigraphically lowest regressive surface of marine erosion” (Plint et al., 2000).
This surface is marked with gutter casts that may incise seaward, but further seaward the
lower portions of the FSST may undergo a sharp coarsening in sediment without an
erosional surface signifying a basinward shift in faces. The upper surface of the FSST is
defined by the SB and is marked with an “up-dip regional subaerial unconformity produced as a surface of sediment bypass during relative sea-level fall, and a correlative
13 Texas Tech University, Graham Butler, December 2010
conformity that is the sea floor at the time of relative sea-level lowstand” (this is also the
“master” onlap surface of the overlying LST) (Plint et al., 2000). As sea level is
transitioning between HST and LST, and the FSST is being deposited, this relative sea-
level fall is not a steady drop but is punctuated by numerous deepenings (these are
flooding surfaces that define the bases of parasequences). These deepenings are often
marked by shale partings where relative sea level deepened enough for shale to be the
predominant lithology. The boundary of these deepenings, which lies directly below the
shale parting and above the shallowing upward limestone, is defined as the high
frequency sequence boundary (HFSB) (Fig. 2.2.4). It is referred to this because onlap
does occur onto the surface although it is of a higher order (i.e. 5th order) bounded within
the HST as opposed to a 4th order sequence bounding a full sequence.
A FSST is also referred to as a phased regression (Felton and Heckel, 1996). As
the name would suggest, the regression is not occurring as one smooth transition but
rather one punctuated by multiple smaller “stepped” regressions superimposed on a
longer-term fall in relative sea level. Together these many related regressions transition
from HST to LST. Although the Bethany Falls Limestone has not been examined for
high-frequency cyclicity, Felton and Heckel (1996) examined the internal, high-
frequency architecture of the highstand/falling stage Winterset Limestone of the Dennis
high frequency sequence, which lies immediately above the Bethany Falls Limestone.
Their findings concluded that what was initially considered a single, long-term regressive
package was in fact “interrupted by sea-level rises of up to intermediate scale, which
caused loss of carbonate production, hence sediment starvation, and resulted in
14 Texas Tech University, Graham Butler, December 2010
deposition of conodont-rich shales” (Felton and Heckel, 1996). These shale partings within the Winterset were traceable for up to 160km (100mi) and break the lower
Winterset Limestone into four Transgressive-Regressive (T-R) packages of underlying shale shallowing upwards into a limestone. These shales represent minor reversals of general regression that predominated during the Winterset deposition (Felton and Heckel,
1996). This overall larger cycle of regression with intermittent deepenings was the cycle from which the term “Phased Regression” originated. John Pope (1996a, 1996b) has also identified that minor cycles, similar to those within the Winterset, appear to be present within the Bethany Falls Limestone. However, his work was restricted to Madison
County, Iowa and made no attempt to correlate those shale breaks across the mid- continent.
2.2.2 Clarification of Common FSST Terms
Stranded Parasequences – which are also referred to as ‘forced regressive
deposits’ are the deposits/features that are left, during decelerated fall in apparent sea
level, which are parasequence in scale, and deposited on the upper slope. They are
quickly abandoned by sea level and exposed. (Posamentier et al., 1990; Van Wagoner et al., 1990) The boundary that separates stranded parasequences is known as a high
frequency sequence boundary and is defined below. Stranded parasequences found in
siliciclastic systems are usually shoreface beach facies and shallowing upwards in nature,
or they are deltaic sediments which were deposited at the mouth of an incised valley, and
15 Texas Tech University, Graham Butler, December 2010
coarsen upwards. When found in carbonate upper slopes to platform margins, reefs or
grainstones will usually be deposited during the forced regression.
Basal surface of forced regression – sometimes referred to as the ‘regressive
surface’, this surface is defined as “a chronostratigraphic surface separating older
sediments of the preceding highstand systems tract, deposited during slowing rates of
relative sea-level rise and stillstand, from younger sediments, deposited during the base-
level fall” (Hunt et al., 1992)
Forced Regressive Wedge Systems Tract – also known as the ‘Falling Stage
Systems Tract’ but some choose to use this term due to FSST’s use elsewhere in geological literature with reference to lowering of flood waters. The FRWST is comprised of two parts, the forced regressive slope wedge (FRSW) and the forced regressive basin-floor fan. The forced regressive slope wedge portion is the stranded parasequences and the forced regressive basin-floor fan is the basin debris component deposited at the same time as the slope wedge.
High Frequency Sequence Boundary – the surface of the stranded parasequences
with which they onlap onto each other. Although by definition this is a sequence
boundary, knowing that it is a forced onlap due to lack of sediment and/or apparent sea
level, it is aptly named a HFSB, and is understood that the surface which bounds above is
the SB.
16 Texas Tech University, Graham Butler, December 2010
2.3 Sequence Stratigraphy vs. the Cyclothem Model
The Kansas cyclothem model is effective in describing the vertical stacking of lithofacies observed on the Mid-continent platform, but regional correlations of
individual cyclothems into the basinal region of southern Kansas and Oklahoma
presented problems over the years due to abrupt changes from carbonate to siliciclastic
lithologies (Watney, 1989). The difficulty in correlating individual cyclothem members
across this transition led to significant misunderstanding of the timing of sedimentation
between the platform and basin, and confusion in interpreting the geometry of the shelf
margin itself.
Sequence stratigraphy provides the conceptual framework within which to interpret
these anomalies as well as a clear set of lithofacies criteria to define the
chronostratigraphic surfaces across the platform and into the basin. However, sequence
stratigraphy wasn’t applied to the cyclothem issue until the late 1980s, partly due to the
hurdle to gain acceptance for this new concept. When looked at more closely, sequence
stratigraphy not only explained the sudden change in lithologies (‘Shazam lines’), which
made inter-basin correlation possible, it grew to explain the mystery of exposure surfaces
and flooding events within large limestone packages.
Sequence boundaries, when compared with the cyclothem model, do not
correspond with the boundaries of a cycle but rather fall within. When applied to the
Swope Sequence, the sequence boundaries fall at the first appearance of the Elm Branch
Shale and the top of the Bethany Falls Limestone (Swope Lms) (Fig. 1.1). Using the
cyclothem model, the cycle begins as the last appearance of the Elm Branch Shale and
17 Texas Tech University, Graham Butler, December 2010
ends at the top of the Galesburg Shale, which overlies the Bethany Falls limestone (Fig
1.1). This method of using non-marine (outside) shales as bounding units ignores the
subaerial exposure surfaces that coincide with sequence boundaries and their usefulness
in correlation (Wilke, 2000). In addition to ignoring subaerial exposures, this method of
correlation fails to take into account the instances when the SB occurs within the outside shale. The benefits of correlation using these exposure surfaces and flooding surfaces, minor deepening events usually marked by a shale sediment (shale breaks), is that they are time correlative. In addition to the differing bounding criteria, there remains a major conceptual difference between the concept of a cyclothem and that of sequence stratigraphy. The definition of a cyclothem is one of facies stacking and can be time transgressive (Wilke, 2000). Sequence stratigraphy on the other hand, by definition, is contingent on boundaries being time correlative that are independent of lithostratigraphy
(Mitchum et al., 1977; Watney et al., 1995).
When placing a cyclothem within a sequence stratigraphic framework it is necessary to identify the constituents in terms of the new methodology. Once that is done it is imperative that the cyclothem terminology is thrown out and only the “new” sequence stratigraphy terminology utilized. The majority of the outside shale is equivalent to the lowstand deposit or the LST component of the sequence. Part of the way through the outside shale there is a break where the shale changes and more marine biota is present (Heckel, 1994). This is an internal flooding surface which marks the beginning of the TST. The upper portion (above the FS) of the outside shale and the entire middle limestone member together comprise the TST. Following the middle
18 Texas Tech University, Graham Butler, December 2010
limestone in the cyclothem is the core shale member. This member is the basin deposit
of a highstand but is termed the MFS interval in sequence stratigraphic terminology. The
classic upper limestone member of the cyclothem is the regressive systems tract of the
sequence and is the HST and FSST deposit. This deposit is marked at the top by an
exposure surface and sometimes a paleosol. Now that the LST, TST, core shale, and
HST have been related to the members of a cyclothem, it is possible to proceed in a
strictly sequence stratigraphic mindset.
2.4 Geologic Setting and Paleogeography
During the Missourian the supercontinent of Pangea was in the late stages of
formation. Although forming a large supercontinent, a significant portion of the interior
was submerged by a large “Midcontinent Sea, which connected to the Panthalassa Sea
(the Protopacific ocean) in the west” (Rosscoe, 2008; Algeo and Heckel, 2008) (Fig. 1.2).
To the south of the Midcontinent Sea were the Arbuckle-Wichita orogenic belts. The
Ancestral Rocky Mountains were located to the northwest of the inland basin. During
this time the southern Midcontinent was located within the equatorial zone, 5 – 10
degrees north of the equator, and the northern Midcontinent was located 10 – 25 degrees
north (Heckel, 1977). (Fig. 2.4.1)
19 Texas Tech University, Graham Butler, December 2010
Figure 2.4.1: Close up of Midcontinent during Missourian continental flooding (Blakely, 2005).
This placement within the subtropics, coupled with the waxing and waning of Gondwana ice caps (Algeo et al., 2008), allowed for well-developed cyclical transgressive-regressive carbonate packages. These units strike north-northeast to south-southwest and dip to the west at approximately 5.5m/km (Heckel, 1978).
Initially the outcrop belt was broken down into facies belts (Heckel, 1978) (Fig.
2.4.2), which are described according to shoreward-basinward limits of dominant sediment types. To the north, bounded by limited outcrops and an east-west line running about half-way between Kansas City and the Iowa-Missouri border is the Northern
Shoreward Facies Belt. This facies belt, capping the regressive limestones, is defined by well developed tidal flats. Next, bounded to the south by an east-west line across central
Kansas, is the Open Marine Facies Belt. The Open Marine Facies Belt is typically the
20 Texas Tech University, Graham Butler, December 2010
largest and consists of a skeletal limestone that often grades into an oolite shoal cap.
South of the Open Marine Facies Belt is the Phylloid Algal Belt, which consists of
skeletal limestone which grades into an algal limestone above. This facies is bounded to
the south by the Terrigenous Detrital Facies belt just north of the Kansas-Oklahoma
border. The Terrigenous Detrital Facies, although south of the arch and research area,
consists of terrigenous sandstones and shales.
21 Texas Tech University, Graham Butler, December 2010
Figure 2.4.2: NE Kansas and surrounding states overlaid with facies belts. (Modified after Heckel, 1978).
22 Texas Tech University, Graham Butler, December 2010
At the peak of highstand the shoreline was located approximately in central Iowa, but as eustatic sea level fell to lowstand, the shoreline relocated southward into Kansas.
(Heckel, 1980, Wilke, 2000) During this time eastern Kansas and western Missouri were
tectonically active causing the region to be marked by subtle structural features that
influenced deposition. The Bourbon Arch, which is oriented northwest-southeast in the
eastern portion of Kansas, divides the shelf between two basins: the Forest City Basin to
the north and the Cherokee Basin to the south (Fig. 2.4.3). The Nemaha Uplift, which
runs from the southeastern tip of Nebraska southwest through Kansas, divides the Forest
City Basin and Cherokee Basin to the east from the Salina and Sedgewick Basins to the
west (Wilke, 2000; Rosscoe, 2008) (Fig. 2.4.3). Smaller regional structural highs also
influence deposition, such as the Raytown Anticline located in northeast Kansas City,
Missouri.
The study area, which is completely contained within the Midcontinent basin,
stretches along an outcrop belt from Winterset, IA to Bronson, KS, which is located at the
ramp crest (Mossler, 1971). Although the BFL deposits continue southward into
Oklahoma, they are substantially thinner and deeper water deposits. This outcrop belt
(Fig. 2.4.2) extends from NE Oklahoma crossing the southeastern corner of Kansas
through the Kansas City area, into northwestern Missouri. The Missourian outcrop belt
then curves around into southwest Iowa, skirting Des Moines to the south, and into
eastern Nebraska, defining the north end of the Forest City Basin. The southern limit of
glaciations is approximately just south of Kansas City and extends perpendicular to strike
in an East-West broad arc. Although Pleistocene glaciation did not affect exposures of
23 Texas Tech University, Graham Butler, December 2010
the Swope Limestone in the Kansas City area, exposures further north were greatly
affected and are often poorly exposed as a result (Heckel, 1996). Of the fourteen
outcrops investigated in this study, only two of them are north of greater Kansas City,
and they are extended across approximately the same distance as the other twelve
outcrops.
Figure 2.4.3: Base map showing outcrop localities with major regional features (Modified after Lee, 2005). Refer to Appendix E for GPS coordinates.
24 Texas Tech University, Graham Butler, December 2010
2.5 Previous Research
The initial investigation into the Bethany Falls Limestone, and the investigation
which gave it its name, was performed by Broadhead (1868). He identified the Bethany
Falls Limestone where it was exposed at the waterfall in Bethany, Missouri. The
Bethany Falls Limestone was not published on again until after a study of the outcrops at
Swope Park, Missouri. The Bethany Falls Limestone was included within the Swope
Limestone in a study done by Moore (1932).
In 1966 Payton published detailed descriptions and a petrographic analysis of the
Swope Limestone Formation from detailed outcrop work from Kansas City, Missouri
northward into Iowa. Through his work along the outcrop belt he named nine facies
within the Bethany Falls using thin sections to conduct point counts and interpreted
environments of deposition for the nine facies.
In 1971 John Mossler published a comprehensive description of diagenetic
alteration (and dolomitization) of the Swope Formation in southeast Kansas. This study
was followed by Mossler (1973) with a detailed sedimentological study of the Farlinville
Quarry (Swope) as well as outcrops farther south within Kansas. In this study Mossler
(1973) identified and described four lithofacies within the Bethany Falls Limestone
(Swope).
Phil Heckel (1977; 1978; Heckel and Baesemann, 1975) introduced the Kansas cyclothem model and published extensively on lithofacies constituents and their interpretation. In Heckel and Baesemann (1975), the relationship between conodont distribution and the cyclic rock sequence was identified. This was quickly followed up 25 Texas Tech University, Graham Butler, December 2010
by Heckel (1977) with additional lines of evidence for interpreting evolving depositional
environments within cyclothems and presented a more thorough depositional model that
encompassed both vertical and lateral lithofacies sequences in terms of realistic
sedimentary processes. In 1978 Heckel led a fieldtrip and published a guidebook for the
AAPG/SEPM which serves as an excellent summary of the 1975 and 1977 papers along
with field examples. After the early 1970s it was over a decade before another diagenetic
study was done on the Swope by Nollsch (1983).
In the early 1980s Lynn Watney (1980; 1984; 1985) did a substantial amount of researching on the Lansing-Kansas City Groups, incorporating studies of cyclical sedimentation, internal reservoir trends (Nebraska), and evaluation of the significance of
tectonic sedimentary control versus eustatic control of Upper Pennsylvanian cyclothems.
Watney and French (1989), in a guidebook compiled for a field conference, focused on
“examining current approaches to deciphering the history of cyclothemic depositions of
the Upper Pennsylvanian (Missourian) Lansing and Kansas City groups and to evaluate
the applicability of sequence-stratigraphic concepts”. Later papers by French and
Watney (1991; 1993) focused on the Bethany Fall’s oolite facies as an analogue for age-
equivalent ooid-grainstone reservoirs both in terms of stratigraphy and depositional
setting.
In 1992 Stover made a very localized and detailed examination of Farlinville
Quarry, located east of the Farlinville road cut location (Fig. 2.4.3), which focused on an
in-depth stratigraphic and depositional investigation. Stover (1992), as well as French
and Watney (1989, 1991, 1993), mentioned the subaerial exposure surfaces within the
26 Texas Tech University, Graham Butler, December 2010
Bethany Falls Limestone. These papers were used as a basis for gamma-ray log analysis
(Carr et al., 1995) to identify exposure surfaces and trace and rare earth elements (Hoth et
al., 1998) as a key to understanding reservoir development.
Pope (1994, 1995, 1996) published a series of abstracts concerning the
depositional cycles within Midcontinent limestone formations. Pope’s (1994) work in
Taylor County, Iowa noted that flooding surfaces were correlatable to sections further
north, and that they represent minor eustatic cycles. For the Bethany Falls limestone he
noted at least three minor transgressive – regressive cycles to be present at localities in
three Iowa counties (Pope, 1995a). In Pope’s final abstract (1995b) he incorporated
northern Missouri cores, in which he found the same three transgressive – regressive
cycles.
Felton and Heckel (1996) published a paper describing the small-scale cycles
within the Winterset Limestone (Dennis). The Winterset Limestone occurs one sequence
(Dennis) above the Bethany Falls. The Winterset Limestone should share many of the
same fundamental controls on deposition as the Bethany Falls Limestone, also being a
Pennsylvanian HST deposit. Felton and Heckel (1996) noted that shale breaks identified
within the Winterset are marked by increased conodont abundances. This paper also
echoes the sentiments of the Pope abstracts (1994; 1995; 1996) in that preliminary results
point towards the presence of similar minor cycles with internal stratigraphic relations
within the Bethany Falls limestone (Felton and Heckel; 1996).
In 2008, Steven Rosscoe, published his immense work on the early Late
Pennsylvanian conodont distribution and classification. His research included a
27 Texas Tech University, Graham Butler, December 2010
function-based taxonomic method specifically to revise Idiognathodus and
Streptognathodus species from the Lost Branch to Dewey sequences. This study also
includes specific research into conodont species zones within the Lost Branch, Hepler,
Shale Hill, Hertha, Swope, Mound Valley, Dennis, Hogshooter, Cherryvale, and Dewey
sequences of the Midcontinent. The results of this comprehensive taxonomic assessment
can be used as a robust framework within which to place detailed conodont
biostratigraphic work completed here for the Bethany Falls Limestone.
28 Texas Tech University, Graham Butler, December 2010
CHAPTER III
METHODOLOGY
3.1 Sampling
The localities chosen for this study were largely based on accessibility and
outcrop condition. All 14 outcrops are accessible from the road or are on public land.
They stretch across Kansas, Missouri, and Iowa and are spread out over approximately
300mi in a south-southwest to north-northeast direction from Bronson, Kansas to
Winterset, Iowa (Fig. 2.4.3). Twelve outcrops are located in the Kansas City area and
south. The outcrops are more prevalent in the southern half of the research area due to
the southern limit of glaciations ending in the vicinity of Kansas City, MO and the
abundance of highway road cuts (Fig. 2.4.3). This close proximity allows for more
reliable correlations and interpretations from one location to another.
All fourteen outcrops were measured, described, and sampled. The Bethany Falls
limestone was thoroughly sampled at every outcrop for all facies but special attention
was paid to the shale partings. All shale partings that could be identified were marked on
the stratigraphic column and thoroughly collected. Where it was possible, at least 1000g
of each shale parting was collected. However, some partings were too weathered, too
thin, or too difficult, and less material was collected.
29 Texas Tech University, Graham Butler, December 2010
3.2 Sample Processing
The collection of all shale samples was done by Graham Butler, the only
exception being sample Jingo S8, with all of the lab work done by both Graham Butler
and Dr. James Barrick. The Jingo S8 sample was collected and processed by Dr. Steven
Rosscoe (Rosscoe, 2008). All 33 shale partings were brought back to Texas Tech
University and laid out to air dry. Although drying is a standard step in processing shale
prior to fossil extraction, the bags of sediment were given extra time to air dry, since
when collected, most of the sediment was highly saturated. After being left to air dry, to
eliminate most of the moisture weight, approximately 1 – 1.5 kilograms of the sediment
was weighed out. However, samples from shale partings with less sediment, all of the
sediment collected was weighed out and prepped. After drying, the sediment was soaked
in either buffered formic acid (HCO2H) or kerosene. Kerosene was used to disaggregate
the clay-rich shales since they are not held together as well as the calcareous shales that
require formic acid. None of the shales were organic-rich black and grey shales so the bleach or updated hydrogen peroxide method (Rosscoe, 2008) was not utilized. Initially all samples were treated using the kerosene method although it was quickly discovered that there was either too much sediment that did not disaggregate, still far too much calcareous debris, or just too much unbroken sediment to process for conodonts.
Since the conodonts are phosphatic, the sediments that did not responded well to kerosene were then processed with the buffered formic acid. Once the samples were soaked in the kerosene or acid for approximately 24 hours the solution was drained, with special care being taken to preserve any loose sediment, and the sediment was let soak in
30 Texas Tech University, Graham Butler, December 2010
hot tap water overnight to help further disaggregate the sediment. The samples were then
drained and wet-sieved. The two sieve sizes used were 120 and 230. Once carefully
sieved the sediment was put in the oven at 70oC until all moisture was evaporated.
Once the samples were dried and sieved, they were picked manually. In
retrospect, 1500g and in some cases upwards of 2000g, was too large of a sample for
some of the shale partings lower in the section. The samples were examined under a
microscope and all conodont elements, including fragments, were removed, and placed in
parting specific slides.
The hand samples of the different lithofacies were collected by Graham Butler
and Peter Holterhoff and brought back to Texas Tech University. All cutting of the
samples, as well as billets prepared for thin sections, was performed by Graham Butler at
Texas Tech University. Billets were then mounted to glass slides using blue epoxy to highlight porosity and thin sections were prepared for petrographic examination.
3.3 Data Analysis
All picked conodonts were placed on slides with platform side up, so that identification could be made. It is the individual ridge and blade configuration which differentiates the conodonts into genus and species (Rosscoe, 2008).
All conodont identification was performed by Dr. Steven Rosscoe at Hardin
Simmons University in Abilene, Texas. Dr. Rosscoe provided genus, species, and in some cases subspecies level classification, of the adult conodonts. Juvenile conodont
31 Texas Tech University, Graham Butler, December 2010
elements, aside from giving us valuable count numbers, do not contribute to the
identification of species level classification since juveniles from numerous species of the
same genus look relatively similar, making reliable identification impossible. Once
generic and species level identifications of the material had been completed,
environmental interpretations based upon the presence and abundance of the different
conodont taxa were made.
Once the total conodont count was completed, counting only conodont P1
elements with platforms intact, the number could be compared with the sediment weight.
Comparing the initial weight of the sediment, pre-acidization and pre-kerosene treatment,
with the number of total conodonts found, the number of conodonts per kg could be
calculated. Since different amounts of sediment are processed, this number is more
valuable than the number of total conodonts found, because it compares all the samples
against the same criteria, thus making them relevant and comparable.
32 Texas Tech University, Graham Butler, December 2010
CHAPTER IV
LITHOFACIES AND MAJOR LITHOFACIES TYPES (MFT)
At each of the localities used for this research, the section was measured from the
base of the Bethany Falls limestone or from the lowest exposed portion of the Bethany
Falls outcrop. The base of the Bethany Falls can, unless obscured, be identified as the
sharp contact between the limestone and the underlying black fissile Hushpuckney Shale
(Fig. 4.01).
Figure 4.01: Typical Pennsylvanian cyclothem stratigraphy with sea level and environmental associations (Heckel, 1999).
33 Texas Tech University, Graham Butler, December 2010
From the outcrops, comparisons were made to previous descriptions, and were
described by color, lithology, fossil constituents, and sedimentary structures. Selected
carbonate lithologies were slabbed, polished, and further examined for lithofacies
identification. Through those identifications the Bethany Falls Limestone can be grouped
into four lithofacies: Skeletal Packstone, Skeletal Wackestone, Skeletal Mudstone, and
Coated Grainstone facies. These four faces represent the overall shallowing trend found within the Bethany Falls. (Fig. 4.02)
Fine to Coarse Siliciclastics Ooid, Peloid, and Foram Grainstone/Packstone Peloid and Skeletal Packstone & Wackestone
Siltstone/Sandstone Phylloid Algal Buildups Skeletal Wackestone and Shale
Figure 4.02: Depositional facies model of Pennsylvanian low angle ramp geometries with ooid shoals. (Markello et al., 2008).
34 Texas Tech University, Graham Butler, December 2010
4.1 MFT – 01: Skeletal Mudstone Facies
Dominant Components: Mud Subordinate Components: Brachiopods, bryozoans, algae, forams, spicule casts (blocky calcite replaced) Cement: Blocky calcite
Texture: Mudstone
Fabric: Thickly bedded, abundant styolites
Porosity: Microporosity , fracture porosity, lesser intergranular porosity (< 2%)
Thin section: plane polarized light, blue epoxy
Figure 4.03: Thin section image of skeletal mudstone facies LC-KS-B4 sampled from bed four the 17mi S. of Louisburg KS outcrop. Note large brachiopod fragment. (Scale bar = 500um).
35 Texas Tech University, Graham Butler, December 2010
Figure 4.04: Polished Slab of skeletal mudstone sample LC-KS-B4.
Figure 4.05: Thin section of skeletal mudstone sample U-MO-10b collected from the base of bed 10 at the Utica, MO outcrop. (Scale bar = 500um).
36 Texas Tech University, Graham Butler, December 2010
Figure 4.06: Cut and polished hand sample of skeletal mudstone collected from bed 10 at Utica, MO. (U-MO-B10). (Scale bar = 500um).
4.1.1 Major Lithofacies Description: Skeletal Mudstone
The skeletal mudstone facies, which varies in thickness from 0 to 10s of
centimeters, is present at most outcrops described in this study. Bedding is not
distinguishable in hand sample although larger (outcrop scale) beds, on the order of
0.25m – 0.5m, are present. At some localities these beds are occasionally separated with
a millimeter-scale shaly parting that are too thin for sampling. The mudstone is highly
bioturbated, which obliterated any detailed bedding structures and aided in the
disarticulation and random distribution of skeletal grains. In outcrop the mudstone
appears similar to the skeletal wackestone facies. It contains similar light grey-grey
mottling and displays the nodular weathering also referred to as the “peanut” zone.
37 Texas Tech University, Graham Butler, December 2010
The only grains present in this facies are skeletal in nature and comprise less than
10% of the rock. The dominant skeletal grains observed were disarticulated brachiopod
fragments and brachiopod spines (both individual spines and spine casts). In addition to
the brachiopod fragments, bryozoans, algae, forams, crinoids, and gastropods were
identified from thin section. None of these skeletal constituents are observable in hand
sample.
Porosity within the mudstone facies is minimal. Aside from minimal fracture
porosity, microporosity is present, and minor amounts of intergranular porosity can be
identified. Almost all fractures in the rock have been cemented with blocky cement.
The mudstone’s environment of deposition (EOD) is interpreted as a subtidal, mid
to lower ramp, clear-water carbonate (Moore, 1932) based upon the skeletal constituents,
abundances of those constituents, and rock lithology. The lesser skeletal fragments
coupled with abundant mud indicate a low energy environment found below wave base.
38 Texas Tech University, Graham Butler, December 2010
4.2 MFT – 02: Skeletal Wackestone Facies
Dominant Components: Brachipods, mollusks (silicified), bryozoans
Subordinate Components: Ostracods, forams, brachiopod spines, fusulinids, phylloid algae
Cement: Blocky calcite, mosaic calcite, silica (minor)
Texture: Wackestone
Fabric: Mottled, thin – medium bedded (10 – 25cm)
Porosity: Microporosity: mostly intergranular, some intragranular
Thin section: Plane polarized light, blue epoxy
Figure 4.07: Thin section of skeletal wackestone sample LC-KS-B3-lwr collected from lower bed 3 at the outcrop 17mi S. of Louisburg, KS. Note brachiopod spine at top and ostracod near bottom. (Scale bar = 500um).
39 Texas Tech University, Graham Butler, December 2010
Figure 4.08: Hand sample of skeletal wackestone LC-KS-B3-lwr collected from the lower bed 3 at the 17mi S. of Louisburg, KS outcrop. Note the burrow-mottled fabric.
Figure 4.09: Thin section of skeletal wackestone sample #U-MO-B5 collected from bed 5 at the Utica, MO outcrop. Note: the fossil constituent is a brachiopod spine. (Scale bar = 500um).
40 Texas Tech University, Graham Butler, December 2010
4.2.1 Major Lithofacies Description: Skeletal Wackestone
The Skeletal Wackestone facies is not only the most common facies within the
Bethany Falls Limestone but is present at all outcrops examined in this thesis. The outer appearance of this facies, which commonly is in excess of 2 meters thick, is a light and dark grey mottled pattern. This mottling, which is visible in both hand sample (Figure
C.3) and outcrop (Figure C.4), “has been interpreted as the result of preferential
infiltration of meteoric water through more permeable zones during subsequent subaerial
exposure” (Wilke, 2000). In outcrop as well as in hand sample the mottled zone weathers
around these nodules and is commonly referred to as “peanut” due to the shape of the
weathered nodules. The bedding is wavy and thin to medium scale (10 – 25cm) sometimes containing shale partings.
The facies contains numerous skeletal types including brachiopod shells and spines, ostracods, forams, bryozoans, fusulinids, echinoderms, and mollusks. The occasional calcite-filled algal cast was also noted. The dominant matrix is mud and contains micro, intergranular, and to a lesser degree, intrapartical porosity.
The skeletal constituents and abundant mud indicate that the lithofacies was deposited in an in a normal, low-energy, marine environment. Compared to the mudstone this rock was likely deposited shoreward, due to the increase in fossil abundance, but still below wave base (Moore, 1932)
41 Texas Tech University, Graham Butler, December 2010
4.3 MFT – 03: Skeletal Packstone:
Dominant Components: Brachiopods, gastropods, bryozoans
Subordinate Components: Trilobites, forams, brachiopod spines
Cement: Blocky calcite, mosaic calcite
Texture: Packstone
Fabric: Mottled, thin – medium bedded (10 – 25cm)
Porosity: None observed
Thin section: Plane polarized light, blue epoxy
Figure 4.10: Thin section of a brachiopod-dominated skeletal packstone collected from bed 9 at the Utica, MO outcrop (U-MO-B9). (Scale bar = 500um).
42 Texas Tech University, Graham Butler, December 2010
Figure 4.11: Cut and polished skeletal packstone slab from bed 9 Utica, MO outcrop (U-MO-B9).
4.3.1 Major Lithofacies Description: Skeletal Packstone
The skeletal packstone shares almost the identical lithology as the dominant wackestone except it contains a higher percentage of skeletal constituents. In addition to the lithology it also shares the same thin-medium bedding as the wackestone.
The diverse skeletal packstone contained diverse skeletal constituents including brachiopods, brachiopod spines, bryozoans, echinoderms, forams, fusulinids, mollusks, and the rare trilobite. All of the skeletal debris was highly agitated with no observable
orientation of the grains. The grains were held in a mud matrix with no identifiable
porosity and were cemented with blocky and mosaic calcite.
Others (Wilke, 2001; Heckel, 1989) have mentioned the presence of a Phylloid
Algal facies present at the southern outcrops. This was not noticed in the current research
43 Texas Tech University, Graham Butler, December 2010
so it was not included in these descriptions. Although algal material was noted within the
skeletal packstone it did not occur in high enough percentages to warrant its own
lithofacies.
The skeletal constituents and abundant mud indicate that the lithofacies was
deposited in an environment above wave base and in a normal, high-energy, near shore
marine setting. The large amount of skeletal constituents coupled with the decrease in
mud indicates that the environment contained consistent wave agitation. This wave
agitation, which is consistent with a near-shore environment, also is responsible for the
winnowing of the muds. This lack of stratification can easily be attributed to
bioturbation. (Moore, 1932)
4.4 MFT – 04: Coated Grain Facies
4.4.1 MFT – 04a: Ooid Grainstone (porous)
Dominant Components: Ooid
Subordinate Components: sparse brachiopod and gastropod skeletal fragments, some ooid pores contain dead oil (FIG. ##)
Cement: Blocky calcite, mosaic calcite
Texture: Grainstone
Fabric: large (meter scale) cross-beds (ex. Utica, MO, Bronson, KS)
Porosity: Oomoldic porosity
Thin section: plane polarized light, blue epoxy
44 Texas Tech University, Graham Butler, December 2010
Figure 4.12: Thin section of porous ooid-grainstone unit at Xenia, NW locality sample # XNW02. The blue epoxy = porosity. (Scale bar = 500um).
Figure 4.13: Cut and polished porous ooid-grainstone handsample of XNW02. Note bedding and porosity visible as shadows.
45 Texas Tech University, Graham Butler, December 2010
Figure 4.14: Thin section from the base of the upper ooid grainstone package at Jingo, KS. Sample #Jingo_base-top02 with porosity highlighted by blue epoxy. (Scale bar = 500um).
46 Texas Tech University, Graham Butler, December 2010
Figure 4.15: Handsample cut and polished from the lower portion of the upper ooid grainstone unit at Jingo, KS. Note the dead oil in the lower (black) portion of the hand sample.
47 Texas Tech University, Graham Butler, December 2010
4.4.2 MFT – 04b: Ooid Grainstone (tight)
Dominant Components: Replaced ooids
Subordinate Components:
Cement: Blocky calcite Cement and mosaic calcite
Texture: Grainstone
Fabric: mud and large amounts of calcite
Porosity: None
Thin section: plane polarized light, blue epoxy
Figure 4.16: Thin section from the uppermost tight ooid grainstone package from within a few inches of the sequence boundary. All ooids from within sample FV-RD-TOP are completely replaced with calcite contain no porosity. (Scale bar = 500um).
48 Texas Tech University, Graham Butler, December 2010
Figure 4.17: Polished hand sample of the tight ooid grainstone slab cut for thin section U-MO-TOP.
Figure 4.18: Photograph of reverse side of U-MO-TOP hand sample to show filled root casts.
49 Texas Tech University, Graham Butler, December 2010
4.4.3 MFT – 04c: Ooid Wackestone-Packstone
Dominant Components: Ooids (with preserved laminae), ooids (replaced)
Subordinate Components: brachiopod, mollusk, gastropod skeletal fragments, neomorphosed mud, styolites common
Cement: blocky calcite
Texture: Packstone with some portions Wackestone
Fabric: mud
Porosity: Very minimal oomoldic porosity
Thin section: plane polarized light, blue epoxy
Figure 4.19: Thin section of XNW-02 showing well preserved ooids and the minimal oomoldic porosity in a ooid wackestone-packstone. (Scale bar = 500um).
50 Texas Tech University, Graham Butler, December 2010
Figure 4.20: Close up of ooid wackestone-packstone XNW-01a showing ooid preservation. (Scale bar = 500um).
Figure 4.21: Thin section of ooid wackestone-packstone XNW-01a with porosity filled with calcite cement and dead oil. (Scale bar = 500um).
51 Texas Tech University, Graham Butler, December 2010
Figure 4.22: Polished slab of ooid wackestone-packstone XNW-01a sample. Note styolites at top of specimen.
52 Texas Tech University, Graham Butler, December 2010
4.4.4 MFT – 04d: Peloid-Ooid Grainstone-Packstone (tight)
Dominant Components: Ooids, peloids
Subordinate Components: sparse bivalve skeletal fragments, some pores contain dead oil
Cement: Blocky calcite
Texture: Grainstone with some portions packstone
Fabric: mud
Porosity: Minimal Oomoldic, peloid-moldic, and intragranular porosity
Thin section: plane polarized light, blue epoxy
Figure 4.23: Thin section of peloid-ooid grainstone sample (LC-KS-BF-top) collected from the top grainstone unit at the 17mi south of Louisburg outcrop. (Scale bar = 500um).
53 Texas Tech University, Graham Butler, December 2010
Figure 4.24: Polished slab of sample LC-KS-BF-top collected from the top grainstone unit at the 17mi south of Louisburg outcrop.
54 Texas Tech University, Graham Butler, December 2010
4.5 Major Lithofacies Description: Coated Grainstone Facies
The coated grainstone facies of the Bethany Falls is the facies that varies the greatest from locality to locality. This is to be expected given the movement and shoal dynamics displayed in modern ooid shoal analogues. This facies varies from meters thick at some localities (ex: Bronson, KS, Utica, MO), less than one meter at others (ex. 17mi
North of La Cygne, KS, Hwy 2, MO), and completely absent at one (Winterset, IA).
Within this facies classification there are four distinct grainstone facies: ooid grainstone
(porous), ooid grainstone (tight), ooid packstone-wackestone, and peloid-ooid grainstone-
packstone.
The coated grainstone facies forms the capstone of the Bethany Falls and the top
is easily distinguished by large root tubes filled with orange colored brecciated paleosol
(Fig. 4.17, 4.18). These root tubes vary in depth from just a few centimeters to upwards of 0.25 meters. They are prevalent at all outcrops except the farthest shoreward locality
at Winterset, IA and the most basinward locality at Bronson Quarry. At some localities these root tubes have been completely dissolved and contributed to the karsting of the upper 0.5m of the Bethany Falls (Figure C.6). It is likely that the diagenesis required to
create the karsting is also responsible for the dissolution of the ooids in the porous ooid
grainstone lithofacies since the karsting is only prevalent at outcrops that contain this
lithofacies.
The variation in porosity between the seemingly identical skeletal ooid
grainstones is due to exposure to meteoric dissolution. When the porous ooids are
contained within the same rock as the tight ooids the path of the diagenesis can be seen as
55 Texas Tech University, Graham Butler, December 2010
the porosity worked its way down. A dendritic pattern can be seen around fractures
which acted as pathways for the meteoric water to travel along and obliterate the ooids.
This is also true in reverse. When you have an oomoldic rock that has been completely
replaced by calcite it occurs in a top to bottom pattern and you can identify the extent of
the re-crystallization, which is outlined by porous rock of the same lithology.
In Utica, MO the lower ooid package (tight) and the upper ooid package (highly
porous) are separated by a defined scour defining bed separation. It is inferred that this
scour, if followed basinward, correlates with a flooding surface marked by a shale break.
Possibly due to low sedimentation rates or erosion no shale was deposited this far
shoreward. The reason that the tight ooids are placed above the porous ooids is because
they are separated by an exposure surface. The now porous ooids were deposited, then
exposed, and during this exposure subject to meteoric dissolution. After this exposure
relative sea level rose thus depositing another ooid package on top of the existing one.
The ooid facies, regardless of which subfacies, in many localities caps the top of
the BFL. At the top of this facies, as is noted on the measured sections (Appendix A), all
contain paleosol filled root casts, root casts, or karsted root casts. These root casts and
karsting are indicative or an elongated surface exposure. This surface exposure, which
occurs at the upper most point of the BFL, is the sequence boundary at the top of the
Swope Sequence and separates the unconforming Galesburg Shale sitting atop.
All four different varieties of the coated grain facies are produced in the same
EOD. The coated grain facies is evidence of a tidal shoal EOD. The pure concentric
ooid grainstones are products of the ooid shoal mounds that migrate around the tidal
56 Texas Tech University, Graham Butler, December 2010
shoal environment. The ooid wackestone and ooid peloidal packstones/wackestones are
produced in the inter-shoal region with differing amounts of mud and differing energies.
The ooid grainstones share very similar, in some cases identical, means of formation, but
differ in their constituents and porosity.
4.5.1 Ooid Grainstone Subfacies (porous) Discussion
The porous ooid grainstone subfacies is the most common coated grain subfacies
within the Bethany Falls Limestone. It is found at almost every outcrop that contains the
coated grain facies and is easily identifiable in hand sample. This is due to the outward
appearance of the oomolds, the abnormally low density of the sample, and the crumbling
nature of the rock. It is also easily spotted because at some localities, most notably
Bronson Quarry and Utica, MO, the upper ooid grainstone package (MFT – 04a) displays
beautiful outcrop scale cross-bedding (Figure C.5).
The dominant grains of this subfacies are ooids, most of which have been
dissolved, with some sparse accessory skeletal fragments of gastropods and brachiopods
present. The pore type present is all oomoldic which results in almost zero permeability.
It appears from petrographic analysis that few of the moldic pores appear to be
connected, thus the permeability is probably very low, even though the rock is quite
porous. The dominant cement type is blocky calcite which has replaced all fabric.
57 Texas Tech University, Graham Butler, December 2010
4.5.2 Ooid Grainstone Subfacies (tight) Discussion
The tight ooid grainstone subfacies is more complex than the others because it
only occurs where influenced by multiple episodes of meteoric water infiltration. This
facies differs from the porous moldic facies in that no secondary meteoric cementation
came in after the dissolution event and plugged the molds. The tight molds experienced a
second wave of meteoric cementation. It was observed at the upper portions of the XNW
and Utica, MO outcrops and it very likely is present in some degree at most outcrops.
MFT – 04b is identical lithology to MFT – 04a except for the blocky calcite filling the
moldic pore space. The dominant grains of this subfacies are ooids, most of which have
been dissolved, with some sparse accessory skeletal fragments of gastropods and
brachiopods present.
4.5.3 Ooid Packstone-Wackestone Subfacies Discussion
The ooid packstone – wackestone subfacies is relatively common within the lower
coated grain facies of the Bethany Falls and is very common within the lower coated
grain facies of the Xenia NW outcrop. This subfacies varies between packstone and
wackestone and at times is extremely difficult to differentiate between to which fabric
class it belongs. The dominant grains within the rock are ooids with excellently
preserved laminae and nuclei. Identifiable nuclei appear to all be skeletal grains. Very
scarce mollusk, brachiopod, and gastropod fragments are identifiable as well as
neomorphosed mud. There is little porosity although some oomoldic and inter-granular
porosity is identified in thin section. Some of the pore space contains dead oil.
58 Texas Tech University, Graham Butler, December 2010
The difference between MFT – 04c and MFT – 04b, although both tight ooid
rocks with varying amounts of mud, is that they have been exposed to very different
diagenic processes. MFT – 04c, contain excellent preservation of the internal laminae
and nuclei of the ooids. MFT – 04b contain no remnants of the internal structure of the
ooids as they have not only been dissolved out but have been replaced by blocky calcite.
Since mud is a higher constituent, thus resulting in a packstone-wackestone classification,
it is inferred that the EOD is likely inter-shoal. This inter-shoal region would still contain
abundant ooids but would also contain increased mud and skeletal grains. (Moore, 1932)
4.5.4 Peloid-Ooid Grainstone-Packstone Subfacies Discussion
The peloid-ooid packstone is the least common of the coated grain facies. It
occurs most notably at the La Cygne, KS, Jingo, KS, and Farlinville outcrops although it
does occur in lesser amounts at other outcrops. This inter-shoal grainstone-packstone
predominantly contains peloids although to a lesser amount ooids. These ooids likely
migrated off of the shoals and into the inter-shoal environment. It is also possible that
these peloid-ooid grainstones were deposited further landward than the ooid grainstones
in the shoal region and the ooids were debris from the shoals pushed shoreward. In
addition to the coated grains, sparse brachiopod, bivalve, and gastropod fragments were
noted.
The subfacies, like the others, is dominated by blocky calcite cement and
contained mud. Porosity was present in the form of oomoldic, peloid-mold, and
intragranular porosity. Dead oil was also observed in some of the pore space.
59 Texas Tech University, Graham Butler, December 2010
4.6 MFT – 06: Shale Facies
Dominant Components: conodonts, foraminifera, mollusks, brachiopods, bryozoans, crinoids
Subordinate Components: occasional large brachiopods (> 3cm in length) and rare large articulated crinoid stems (>24cm in length and 2cm in width)
Cement: calcite
Texture: shale
Fabric: mud, very thinly bedded to no bedding
Porosity: intergranular porosity
Thin section: N/A
Figure 4.25: Limestone fragments and larger fossil debris collected from shale parting FV-Rd-6 and caught in a 120 sieve after acid treatment.
60 Texas Tech University, Graham Butler, December 2010
Figure 4.26: Insoluble limestone fragments and fossil debris collected from shale parting Jingo S5 and collected in a 230 sieve post acid treatment.
4.6.1 Major Lithofacies Description: Shale Facies
The shale partings throughout the Bethany Falls Limestone are by far the smallest
of the facies in terms of overall volume but are arguably the most important. They are
highly fossiliferous with large amounts of conodonts (at isolated locations reaching 100s
per kg), foraminifera, mollusks, brachiopods, bryozoans, crinoids, These beds are
calcareous shales, which are usually darker near the base of the sections but becoming
thinner and less shaley (more calcareous) as they progress up section. In addition to
becoming more calcareous up section they also become less and less fossiliferous. This
61 Texas Tech University, Graham Butler, December 2010
is most likely due to increased carbonate production further up on the platform coupled
with decreased environmental conditions necessary for fossil production.
62 Texas Tech University, Graham Butler, December 2010
CHAPTER V
CONODONT PALEOCOLOGY AND DISTRUBUTION
5.1 Introduction
All of the conodonts collected from the outcrops were amber in color and none of
the conodonts showed any signs of alteration due to weathering. Numerous P1 (platform
with blade), P2, S, and M elements (Fig. 5.1.1) were collected from the different samples as well as a substantial number of conodont fragments. Intact platforms of P1 elements
were used in abundance counts and species identification. Due to the size and robust nature, P1 elements are the most common.
Figure 5.1.1: Diagram of individual conodont elements (Armstrong and Brasier, 2005).
Previous authors (Heckel and Baeseman, 1975; Heckel, 1977; Watney, 1988;
Felton and Heckel, 1996; Heckel, 2002) used conodonts to substantiate claims of depositional environments and change of environments. Felton and Heckel (1996) used
conodonts to correlate the internal (small-scale) sequences within the Winterset (Dennis)
limestone. While these papers show the utility of conodonts in tracking depositional environments, they do not incorporate abundances of genera and species present into
63 Texas Tech University, Graham Butler, December 2010
their analysis. The objective of this chapter is to describe the abundances of conodont
species recovered from the shale partings sampled in the Bethany Falls and to incorporate
this knowledge into environmental interpretations and stratigraphic analyses.
5.2 Conodont Environment Interpretation
Heckel (1994) proposed a direct conodont genus – water depth relationship (Fig:
5.1.2).
Fig: 5.1.2 Water depth model with associated conodont depth environments (Heckel, 1994)
Nearshore environments typically contain a low diversity of conodonts with low
abundances (less than 20 per kg) (Heckel, 2002). This nearshore environment, in most areas, is dominated by Adetognathus; although locally the genera Idiognathodus and
Streptognathodus can appear at similar abundances (Heckel, 1994; 2002). Another
genus that can occur in nearshore environments, although at much lower abundance than
64 Texas Tech University, Graham Butler, December 2010
the previously mentioned genera, is Hindeodus. It has been inferred that Hindeodus
occurs within the same environments as that of Adetognathus although Hindeodus is
more common in carbonates than in clay shales (Heckel, 1994). Ellisonia, which occurs
in low abundances, has been observed to occur in the same nearshore environment as
Hindeodus (Heckel, 1994) Ellisonia and Adetognathus are most important as shallow
water markers as they are not as environmentally wide ranging as Idiognathodus and
Streptognathodus.
Idiognathodus, which dominated the normal open-marine environment (Heckel,
2002), is widespread in occurrence, and has a large species diversity. A sudden spike in
abundance of Idiognathodus within a flooding interval may imply that normal open-
marine conditions pushed further up the shelf. Possible causes of this abundance peak
include temporary sea level rise and/or a decrease in carbonate production. During these
events, if the thermocline was pushed far enough shoreward, the conodont Idioprioniodus
can be found. This conodont “probably occupied the deeper slightly cooler water mass in
the top of the theromocline” (Heckel, 2002).
It is easy to consider Gondolella a “deep water” conodont because the majority of
Gondolellid conodonts are found in rocks that are inferred to be deep water deposits.
Heckel (1994) examined cyclothems in Nebraska, Kansas, and Oklahoma lower Upper
Pennsylvanian and documented that the genus Gondolella typically occurs in core shales.
However, a core shale in Nebraska (mid-high shelf) represents significantly shallower
water conditions than the equivalent core shale in Oklahoma (basin). With occurrences of
Gondolella high up onto the shelf it is difficult to imagine depth is a primary condition of
65 Texas Tech University, Graham Butler, December 2010
its appearance. It is more feasible that upwelling in tandem with sea level changes would cause environmental conditions to shift shelf-ward (Algeo et al., 2008). Rosscoe (2008) has suggested that Gondolella is a highstand marker that is not solely influenced by depth, but more importantly by water chemistry. Gondolella may have been tracking anoxic bottom waters and that the waters immediately above this well stratified layer was its preferred habitat.
Some species of Idiognathodus have been identified to have lived deeper within the water column. Idiognathodus cancellosus has been identified as a conodont that shares similar environmental affinities to Gondollela, but is much less restricted (Fig.
5.1.2) (Rosscoe, 2009). Idiognathodus cancellosus is present prior to, during, and following the brief appearance of Gondolella at highstand. The appearance of I. cancellosus can be used to indicate conditions close to those that occur at highstand and can thus be used to indicate deepening when Gondolella is not present.
5.3 Conodont Results
The conodont abundances for each shale parting can be found in Appendix E with all shale partings referenced accordingly on their given measured section (Appendix A).
The conodont results and associated shale partings can be broken down into three biofacies types:
Conodont biofacies #1 – Conodont biofacies #1 contains very few to zero
conodonts per kg. When conodonts are found they are typically Idiognathodus with
occasional Hindeodus. This biofacies is most common in only the most shoreward 66 Texas Tech University, Graham Butler, December 2010
conditions. In this case, those conditions are found in the northernmost outcrops (ex.
Winterset, IA; Utica, MO) or near the top of the outcrops because the shoreline had
prograded southward. These partings are inferred to be storm deposits that were rapidly
deposited and are very rich in very well rounded siliclastic sediment. In addition having
very low conodont abundances, these partings contain few other fossil constituents.
According to Heckel (1994) these partings contain fewer conodonts per kg than the
surrounding limestone beds.
Conodont biofacies #2 – Conodont biofacies #2 is a carbonate-rich, thin (typically
1 – 4 cm) shale parting that has only slightly higher abundances than the surrounding
limestone (Heckel, 1994). This biofacies is the most common biofacies within the
Bethany Falls Limestone and is found at almost every outcrop examined. Idiognathodus
is the primary genus present, although much smaller numbers of Streptognathodus,
Idiopriniodus, Ellisonia and Adetognathus were identified.
Conodont biofacies #3 – Biofacies #3 is vastly different than the other two
biofacies in that it contains hundreds of conodonts per kg. This biofacies is unique in that the abundances, almost entirely Idiognathodus with higher amounts of I. cancellosus and
I.sulciferus, are extremely high for a shale break within a HST limestone. The high abundance and deeper water fauna suggest a deepening event. Because of the magnitude of the deepening event, the strata deposited are darker gray, almost fissile shale because very little carbonate production occurring during the event. This biofacies is the least common of the three biofacies and occurs at only three outcrops.
67 Texas Tech University, Graham Butler, December 2010
The outcrops that contain this biofacies (Utica, 63rd St., and Jingo) do so because
they are located upon structural highs that were topographically higher than the
surrounding platform during deposition. Instead of continuous black shale, like that of
the Hushpuckney Shale, being deposited at the same time at surround localities,
conditions were correct for carbonate production on the higher topography. This resulted
in the deposition of argillaceous carbonate beds that grayed shoreward into a sediment-
starved dark gray shale. It is for this reason that the dark gray shale found just above the
base is extremely conodont rich in both species and abundance. In response to location
and greater water depth, the other localities’ dark grey shale lithology found in the upper
portion of the Hushpuckney was being deposited at the same time. It is this reason that
some lines of correlation (example. HFSB #2; HFSB #3) on the cross section are
correlated into the Hushpuckney, even though we are looking at the regressive limestone.
5.4 Conodont Discussion
It appears, from the conodont work performed and from the omission of specific
conodont data from French (1996) and Felton et al. (1996), that conodonts are not reliable
indicators of small scale (5th order) flooding events within the Bethany Falls Limestone.
Although at first very promising, due to the extremely low abundances, the majority of
the conodonts’ shale partings are ineffective to use to distinguish these flooding events.
Almost all of the shale partings contained conodont abundances within the range of those
identified by Heckel (1996) from within the mid-upper portions of the BFL. He
identified that conodont abundances within the middle portion of the regressive limestone
68 Texas Tech University, Graham Butler, December 2010
were on the order of 10 conodonts per kg and dwindled in the upper portion of the
limestone to 1 – 5 per kg. Because the majority of the shale partings contain conodont
abundances that are little more than minor anomalies, recognition of all of the flooding
events using just the conodonts alone is not possible.
69 Texas Tech University, Graham Butler, December 2010
CHAPTER VI
DISCUSSION
6.1 HFSB vs. SB
The BFL is capped by an exposure surface marked by large (< 50cm) root casts and karsting. Given the placement of this laterally extensive exposure surface at the top of the HST and knowing its placement within the sequence stratigraphic model we are able to label this as a major Sequence Boundary (Fig. 2.2.1). (Van Wagoner et al., 1990)
This major sequence boundary, although an exposure surface, differs from those internally within the BFL because it marks the turning point between HST and LST. The
exposure surface(s) within the BFL although technically SBs, because it is an onlap
surface, are only minor deepenings within an overall shallowing upward trend
Within the Bethany Falls Limestone (BFL) there are multiple examples of HFSB
throughout the sections. Whether it is an exposure surface, a scour surface, or a
basinward shift in lithology, thus indicating a deepening, all indicate a mappable point in
which the overall shallowing trend is broken.
Exposure surfaces by themselves are a regressive surface and a marker for a SB or
HFSB. Where coupled with evidence of a deepending, such as bounded by a shale
parting, the exposure surface is also a flooding surface and therefore an internal HFSB.
An exposure surface is not always a HFSB but a HFSB occurs at an exposure surface
which is termed a compound surface. Exposure surfaces, which by definition are “where bounding surfaces of sediment or rock show the effects of being exposed at the Earth’s
70 Texas Tech University, Graham Butler, December 2010
surface”, are non-depositional, commonly erosional, and break the sedimentary sequence
(Esteban, 1983). They are known by many names but most commonly hiatus, break,
flooding surface, and unconformity. An important point to note, especially in this marine environment, is that erosional surfaces need not be subaerial but may also be submarine.
These submarine erosional surfaces will have a correlateable subaerial exposure surface shoreward. Costal and submarine exposure surfaces differ from subaerial exposure surfaces in that they usually are marked by a smooth “scour surface”
At times there are packages of similar facies sitting upon one another and separated by an exposure surface. For example, at the Jingo outcrop there are two distinct ooid packages which are separated by a surface. The lower of the two ooid packages is porous whereas the upper is tight. This difference in porosity is due to distinct differences in diagenetic alteration. The upper package has undergone secondary diagenesis which has filled in the pore space. These two packages, although deposited under the same environmental conditions, are not the same.
Occasionally there are scour surfaces within the outcrop which independently are not indicative of a HFSB although with other criteria they can be identified as such.
When a scour surface occurs within a bed and has the same lithology above and below, it is inconclusive whether or not it is a HFSB. An excellent example of this type of scour surface can be seen in the upper meter of the 63rd and I-435 outcrop (Figure A.5). When
the scour surface occurs at the top of one lithology and immediately above the surface the
lithology is a deeper lithofacies type which shallows upward, it can be inferred that this
was an exposure surface that is also a HFSB. Why there was no conodont rich horizon
71 Texas Tech University, Graham Butler, December 2010
deposited or why it no longer is present could be for any number of reasons. A HFSB
marked by a scour surface can be seen near the top of the Fireman’s Memorial outcrop
(Figure A.6). There is an ooid package (tidal shoal facies) bounded by a scour surface
with a marine carbonate package (open marine facies) sitting directly atop. All high
frequency sequence boundaries can be seen on the individual measured sections as well
as correlated on the cross section.
6.2 Flooding events vs. Galesburg Shale
Although relatively shallow water shale units, the internal flooding units of the
Bethany Falls differ greatly from Pennsylvanian Lowstand shale deposits such as the
Galesburg. The Galesburg is a sticky shallow marine shale, which varies from about
30cm in the measured outcrops to many meters in the basin, and contains no conodonts.
The flooding shales on the other hand are usually very thin (<10cm) calcareous partings,
which punctuate and interbed larger units, and have been shown to contain large amounts
of conodonts. Another primary difference is that the Galesburg (lowstand) Shale overlies
a major sequence boundary whereas the flooding shales will not. They can overlie a
minor HFSB, but will never bound a major SB. Although both defined as shales, they
have very different genetic backgrounds and implications.
72 Texas Tech University, Graham Butler, December 2010
CHAPTER VII
SYNTHESIS
The Bethany Falls Limestone (BFL) is comprised of approximately 2, high-
frequency sequences (HFS) which are well-defined by HFS boundaries/Flooding Surface
(FS) compound surfaces. These HFSB/FS compound surfaces, that are identifiable by
flooding surfaces, shale partings, and exposure surfaces, are marked in Appendix A on
the measured sections. These cycles vary in size from just a few centimeters to upwards
of 5 meters depending on the outcrop’s paleographic location. The outcrops which are
located upon topographic highs contain thin and abrupt transitions from deep water and
open marine facies within the lower few meters of the outcrops. The remainder of these
outcrops, and the other outcrops, are massive limestone packages which are punctuated
by very thin deeper water facies, marked by calcareous conodont-rich shales generally <
5cm in thickness, followed by open marine, shallow marine, shoal, and inner shoal facies.
These shallowing-upward limestone packages are usually on the order of 2 – 4 meters
thick. However the upper most package, the package which contains the shoal and inner
shoal facies, varies upwards to 4 – 6 meters thick. This final high-frequency sequence is
marked by a basin wide exposure surface, marked with large root tubes, and filled with
brecciated paleosol.
A better way to say this might be that the vertical succession of lithofacies at each
section of the BFL across the outcrop belt appears to be quite similar. Thus, it would be
easy to correlate the lithofacies from section to section in a perfectly horizontal, “layer-
cake” fashion (Fig. 2.2.1). The outcrops, in a north-south direction, decrease in age from
73 Texas Tech University, Graham Butler, December 2010
oldest to youngest when placed within a ramp model (Fig. 2.2.2) (Van Wagoner et al.,
1990). Although portions of the outcrops are time correlative to other portions of
neighboring outcrops, the majority of the strata from most BFL outcrops differ in age
from one another. When portions of the Bethany Falls were deposited there was non-
Bethany Falls lithology basinward being deposited at the same time, albeit a much slower rate. To put this in a facies framework, the lower Bethany Falls of the Northern
Shoreward Facies Belt is correlative to the upper Hushpuckney in the southern facies belts. To take it one step further, during the entire deposition of the BFL, there were correlative deep water dark shales (Hushpuckney) being deposited off the shelf in the deep basin (Fig. 7.1). This is difficult to visualize when most diagrams display the BFL directly on top of the Hushpuckney shale (Fig. 4.01) as if they were independently deposited with no time lines overlain onto the cross-section.
74 Texas Tech University, Graham Butler, December 2010
Figure 7.1: Time relationships within a basinward prograding platform system during relative sea- level regression.
Figure 7.1, which is modeled after the BFL’s basinward progradation, depicts the
time relationships which appear within the BFL. At any point in the system there is a
time line that is correlative to the “underlying” black Hushpuckney shale. The
“underlying” shale is termed as such due to its position under the regressive limestone.
Notice at T3 a portion of the BFL is starting to be exposed above sea level. Time cycle
T3 represents a package which is time correlative to an exposure surface updip in the
northern shoreward area, a black shale in the far southern basinal area, as well as the
classic Bethany Falls facies in the mid-platform area. Even though the different
lithologies are time correlative, they are considered two different units.
75 Texas Tech University, Graham Butler, December 2010
The outcrops, although very similar, vary from locality to locality. The largest of
these variations are at those localities situated upon syndepositional structural highs. The
structural highs (ex. Bourbon Arch, Raytown Anticline) display very high frequency,
bed-scale variations in dominant lithology (shale vs. limestone) within the lower 0-5 –
1.5 meters of the Bethany Falls Limestone that developed upon them. This style of
lithofacies variation is absent at investigated outcrops of the Bethany Falls not located
upon structural highs. These bed-scale variations indicate highly volatile bottom-water
conditions, potentially driven by eustatic fluctuations, that accompanied the initial
relative fall in sea level. The variation is documented, not just lithologically through bedded deep water shales and fossiliferous limestones, but also paleoecologically through conodont abundances and species occurrences. The limestone stringers located within
the transitional zone are time correlative to dark shales of the upper Hushpuckney in the
surrounding localities off of the structural highs.
The measured section from Jingo, KS (Figure A.10), is used as the type example
for BFL deposition upon a structural high, which in this case is influenced by the
Bourbon Arch (Fig. 2.1.2). The measured section less than two miles south (17mi S.
Louisburg) displays the identical characteristics (Heckel, 1978). As has been mentioned,
this section contains a series of shale and limestone packages that alternate up section. In
this study only the shales were examined in detail. The shales, starting at the lower most
shale parting, vary up-section and are not distinct individual beds. They transition
(weave) laterally across the outcrop thickening and thinning. The conodonts identified
from within these shales and shale partings were more important due to their volume
76 Texas Tech University, Graham Butler, December 2010
rather than the species present. The shales showed significantly higher numbers of
conodonts per kg than what is normal for a regressive limestone (Heckel, 1996) and these
numbers decreased up the outcrop. This documented that the transitions which occurred
were not as deep with each cycle to deposit the shale and eventually transitioning into strictly a carbonate dominated environment. .
Illustrated in Appendix F, Cross Section #1, is a north-south cross section.
Correlation criteria used for this cross section is based upon the conodont abundances collected from the shale partings (flooding surfaces), litholologic markers, and other FS
indicators (ex. scour marks, exposure surfaces at a lithology transition). Due to the large
expanse between outcrop #1 (Winterset, IA), outcrop #2 (Utica, MO), and outcrop #3
(291 & KY Rd), better control between the localities would greatly increase the strength
of the correlation.(Fig. 2.1.2). It is very like that the majority of the BFL at outcrop #1
and outcrop #2 is not strictly time-correlative with other BFL outcrops to the south, but
are time correlative to the Hushpuckney Shale. An exception to this may be the
uppermost shale partings (ex.U-MO-10, U-MO-12). In addition to the distance between
northern outcrops, weathering condition of the exposures played a role in the confidence
of correlations. At some of the outcrops there is evidence of shale partings although no
samples were able to be collected. These are still valuable in that they allow us to know
there was a break in carbonate deposition. Bethany Falls cycle correlation lines, which
are indicated by solid lines, are chronostratigraphic lines of clinoform packages isolating
individual small scale cycles within an overall regression. Lines of correlation which
lack the confidence to mark with a dashed line are indicated by a dotted line and question
77 Texas Tech University, Graham Butler, December 2010
mark (?). The dotted lines of correlation, given their occurrence at shale partings, scour
marks, and exposure surfaces mean that they are also internal high frequency sequence
boundaries.
The cycles are bounded by HFSB and are labeled HFSB #1, HFS #2, HFS #3,
HFS #4, HFS #5, HFS #6 and HFS #7 are labeled in order from oldest (HFS-1) to
youngest (HFS-7) (Appendix F). They are interpreted as HFSB/FS compound surfaces
because they are more prominent and likely a greater event than other FS noted. Each of
these cycles is a small scale sequence which shallows upward from thin conodont rich
shales to carbonates. In some cases the cycles shallow enough for shoal and near-shore
faces to be recorded. The cycles which are recorded on structural highs are not included
in the numbered cycles due to the lack of ability to confidently correlate laterally. I
believe that this will always be an issue with correlation although with further research
and other correlation techniques greater confidence should be achieved.
Given the biostratigraphic, and more importantly the lithologic evidence,
correlating cycles within the Bethany Falls is possible, within areas of high outcrop
density. With far better outcrop and core control, along with finely measured gamma ray
profiles of these outcrops, it is encouraging that accurate high-frequency correlation
could be possible. This could allow intra-highstand / falling stage-scale clinoform
packages to be accurately mapped from shore to basin with regards to 5th order
sequences. If the methods described in this research are applied to a data set with greater
control, the high-frequency sequences and parasequences within the Bethany Falls
Limestone will be recognizable across the platform with a very high degree of
78 Texas Tech University, Graham Butler, December 2010
confidence. To have a greater understanding into the small-scale relative sea-level cycles
will not only increase the knowledge of the Bethany Falls, but will provide valuable
insight into the individual cycles which together created the larger highstand and falling
stage systems tracts (ex. Swope Cyclothem), and will provide improved understanding
into the dynamics of Late Pennsylvanian sequence regressions as a whole.
79 Texas Tech University, Graham Butler, December 2010
REFERENCES
Algeo, T.J., and Heckel, P.H., 2008, The Late Pennsylvanian Midcontinent Sea of North America: A review: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 268, p. 205- 221.
Algeo, T.J., Heckel, P.H., Maynard, J.B., Blakey, R., and Rowe, H., 2008, Modern and ancient epicratonic seas and the superestuarine circulation model of marine anoxia, in C. Holmden, and B.R. Pratt, Eds., Dynamics of Epeiric Seas: Sedimentological, Paleontological and Geochemical Perspectives: Geological Association of Canada Special Publication, v. 48, p. 7-38.
Armstrong, H.A., Brasier, M.D., 2005, Microfossils 2nd ed., Blackwell Publishing, United Kingdom, p. 249-272.
Bashore, W.M., Araktingi, U.G., Levy, M., and Schweller, W.J., 1994, Importance of a Geological Framework and Seismic Data Integration for Reservoir Modeling and Subsequent Fluid-Flow Predictions, in Stochastic Modeling and Geostatistics, v. CA 3, p. 159 -175.
Bennison, A.P., 1984, Shelf to trough correlations of Late Desmoinesian and Early Missourian carbonate banks and related strata, northeast Oklahoma; in Hyne, N.J., ed., Limestones of the Midcontinent: Tulsa Geological Society, Special Publication No. 2, p. 92-126.
Bennison, A.P., 1985, Trough-to-shelf sequence of the Early Missourian Skiatook Group, Oklahoma and Kansas, in Watney, W.L., Kaesler, R.L. and Newell, K.D., eds., Recent Interpretations of Late Paleozoic Cyclothems: Midcontinent Section, Society of Economic Paleontologists and Mineralogists, Proceedings Third Annual Meeting, p. 219-245.
Blakey, R, 2005, "Colorado Plateau Stratigraphy and Geology and Global and Regional Paleogeography", Northern Arizona University, http://jan.ucc.nau.edu/~rcb7/globaltext2.html (accessed May, 2009).
Boardman, D.R., and Heckel, P.H., 1989, Glacial-eustatic sea-level curve for early Upper Pennsylvanian sequence in north-central Texas and biostratigraphic correlation with curve for Midcontinent North America: Geology, v. 17, p. 802-805.
80 Texas Tech University, Graham Butler, December 2010
Broadhead, G.C., 1868, Coal measures from northwestern corner of Missouri to Glasgow, Howard County, Missouri, in St. Louis Academy of Science, Transactions, v. 2, p. 320.
Carr, T.R, Jaech, J., Guy, W.J., Hopkins, J.F., and Hoth, P., 1995, Use of gamma-ray spectral log to recognize exposure surfaces and associated water tables in a midcontinent carbonate sequence, Kansas, in Annual Meeting Abstracts: American Association of Petroleum Geologists 1995 annual convention.
Emery, D., and Myers, K.J., 1999, Sequence Stratigraphy, Blackwell Publishing Company, United Kingdom, p. 299.
Esteban, M., and Klappa, C.F., 1983, Chapter 1 Subaerial Exposure Environment, in Carbonate Depositional Environments, AAPG Memoir 33, p.1-54.
Felton, R.M., and Heckel, P.H., 1996, Small-scale cycles in Winterset Limestone member (Dennis Formation, Pennsylvanian of northern Midcontinent) represent ‘phased regression,’ in Witzke, B.J., Ludvigson, G.A., and Day, J., eds., Paleozoic Sequence Stratigraphy: Views from the North American Craton: Boulder, Colorado, Geological Society of America Special Paper 306.
French, J.A., Watney, W.L., and Franseen, E.K., 1989, Guidebook for a Field Conference on sequence stratigraphic interpretation and modeling of cyclothems in the Upper Pennsylvanian (Missourian) Lansing and Kansas City groups in eastern Kansas: Kansas Geological Survey 41st annual field trip.
French, J.A., and Watney, W.L., 1991, Integrated Field, Analog, and shelf-scale geologic modeling of oolitic grainstone reservoirs in the upper Pennsylvanian Kansas City Group in Kansas (USA), Reservoir Characterization III, Reservoir Characterization Technical Conference, Tulsa, Oklahoma., November 3-5, 1991.
French, J.A., and Watney, W.L., 1993, Stratigraphy and depositional setting of the lower Missourian (Pennsylvanian) Bethany Falls and Mound Valley limestones, analogues for age-equivalent ooid-grainstone reservoirs, Kansas, in Current Research on Kansas Geology: Kansas Geological Survey Bulletin 235, p. 27-39.
Heckel, P.H., and Cocke, J.M., 1969, Phylloid algal-mound complexes in outcropping Upper Pennsylvanian rocks of Mid-continent: AAPG Bulletin., v.53, p. 1058- 1074.
81 Texas Tech University, Graham Butler, December 2010
Heckel, P.H., and Baesemann, J.F., 1975, Environmental interpretation of conodont distribution in Upper Pennsylvanian cyclothems in North America and consideration of possible tectonic effects, in Dennison, J. M., and Ettensohn, F. R., Eds., Tectonic and Eustatic Controls on Sedimentary Cycles, SEPM Concepts in Sedimentology and Paleontology, v. 4, p. 67.
Heckel, P.H., 1977, Origin of phosphatic black-shale facies in Pennsylvanian cyclothems of midcontinent North America: American Association of Petroleum Geologists, Bulletin, v. 61, p. 1,045-1,068.
Heckel, P.H. et al., 1978, Upper Pennsylvanian Cyclothemic Limestone Facies in Eastern Kansas: Kansas Geological Survey Guidebook Series 2, AAPG/SEPM Annual Meeting, Oklahoma City, April 8-9.
Heckel, P.H., 1980, Palaeogeography of eustatic model for deposition of mid-continent Upper Pennsylvanian cyclothems, in Fouch, T.D., and Magathan, E.R., Eds., Paleozoic Palaeogeography of West-Central United States: Society of Economic Paleontologists and Mineralogists, West-Central United States Paleogeography Symposium 1, Rocky Mountain Section, p.197-214.
Heckel, P.H., 1989, Updated Middle-Upper Pennsylvanian eustatic sea-level curve for mid-continent North America and preliminary biostratigraphic characterization, in Onzième Congrès International de Stratigraphie et de Géologie du Carbonifère, Compte Rendu, 4, p.160-185.
Heckel, P.H., 1994, Evaluation of evidence for glacial-eustatic control over marine Pennsylvanian cyclothems in North America and consideration of possible tectonic effects, in Tectonic and Eustatic Controls on Sedimentary Cycles, SEPM Concepts in Sedimentology and Paleontology, v. 4, p. 65-87.
Heckel, P.H. 1999. Overview of Pennsylvanian (Upper Carboniferous) stratigraphy in Midcontinent region of North America, in Heckel, P. H., Eds., Guidebook, Field trip #8, XIV International Congress on the Carboniferous-Permian, Kansas Geological Survey Open File Report 99-27, p. 68-112.
Heckel, P.H., 2002, Genetic stratigraphy and conodont biostratigraphy of upper Desmoinesian-Missourian (Pennsylvanian) cyclothem succession in mid- continent North America: Canadian Society of Petroleum Geologists, Memoir 19, p. 99-119.
82 Texas Tech University, Graham Butler, December 2010
Heckel, P.H., Boardman, D.R., and Barrick, J.E. 2002, Desmoinesian-Missourian regional stage boundary reference position for North America, in L.V. Hills, C. M. Henderson, and E. W. Bamber (eds.), Carboniferous and Permian of the World, Canadian Society of Petroleum Geologists Memoir 19,. p. 710-724.
Hoth, P., Carr, T.R., Bau, M., and Dulski, P., 1998, Trace and rare-earth elemental variation in a midcontinent carbonate sequence – a key to understanding reservoir development, in Proceedings Pennsylvanian and Permian Geology and Petroleum in the Southern Midcontinent, Oklahoma Geological Survey Workshop, April 7-8, 1998.
Hunt, D. and Tucker, M.E., 1992, Stranded parasequences and the forced regressive wedge systems tract deposition during base-level fall: Sedimentary Geology, 81, p. 1-9.
Joeckel. R.M., 1999, Paleosol in Galesburg Formation (Kansas City Group Upper Pennsylvanian), Northern Midcontinent, U.S.A.: evidence for climate change and mechanisms of marine transgression: Journal of Sedimentary Research, 69, p. 720-737.
Klein, G.deV., 1992 , Climatic and tectonic sea-level gauge for Midcontinent Pennsylvanian cyclothems: Geology, April 1992, v. 20, no. 4, p. 363-366.
Lee, W., 2005, The Stratigraphy and Structural Development of the Forest City Basin in Kansas, Kansas Geological Survey Bulletin 51.
Markello, J.R., Koepnick, R.B., Waite, L.E., and Collins, J.F., 2008, The carbonate analogs through time (CATT) hypothesis and the global atlas of carbonate fields – a systematic and predictive look at Phanerozoic carbonate systems: SEPM Special Publication 89, p.15-45.
Miller, D.E., 1966, Geology and ground-water resources of Miami County, Kansas, Kansas Geological Survey Bulletin 181, p. 66.
Mitchum Jr., R. M., Vail, P.R., and Thompson, S. III, 1977, Seismic stratigraphy and global changes of sea level. Part 2: The depositional sequence as a basic unit for stratigraphic analysis, in Payton, Eds., Seismic Stratigraphy Applications to hydrocarbon exploration, AAPG, Memoir 25, p. 53-62.
Moore, R.C., 1932, Kansas Geological Society, 6th annual field conference, Guidebook, p. 85.
83 Texas Tech University, Graham Butler, December 2010
Mossler, J.H., 1971, Facies and diagenesis of Swope Limestone (Upper Pennsylvanian) southeast Kansas, University of Iowa.
Mossler, J.H., 1973, Carbonate Facies of the Swope Limestone Formation (Upper Pennsylvanian) southeast Kansas: Kansas Geological Survey Bulletin 206, Part 1.
Nollsch, D.A., 1983, Diagenesis of Middle Creek and Bethany Falls Limestones, Swope Formation, Upper Pennsylvanian (Missourian), midcontinent North America, Department of Geology, University of Iowa, Iowa City, IA.
Nummedal, D., 1992, The falling sea level systems tract in ramp settings, Society of Economic Paleontologists and Mineralogists theme meeting, Mesozoic of the Western Interior, Abstracts with Programs, Fort Collins, Colorado, Rocky Mountain Section, Special Publication, p. 50.
Payton, C.E., 1966, Petrology of the carbonate members of the Swope and Dennis Formation (Pennsylvanian), Missouri and Iowa: Journal of Sedimentary Petrology, v.36, no. 2, p. 576-601.
Plint, A.G., and Nummendal, D., 2000, The Faling stage systems tract: recognition and importance in sequence stratigraphic analysis, in Hunt, D. & Gawthorpe, R.L. Eds. Sedimentary Responses to Forced Regressions, Geological Society, London, Special Publications 172, p. 1-17.
Pope, J.P., 1994, Depositional cycles in the Bethany Falls Limestone member, Swope Formation (Pennsylvanian, Missourian), Taylor County, Iowa [abstract ]: Missouri Academy of Science Transactions, v. 28, p. 132.
Pope, J.P., 1995, Depositional cycles in the Bethany Falls Limestone Member of the Swope Formation (Pennsylvanian, Missourian), Northern Missouri [abstract]: Missouri Academy of Science Transactions, v. 29, p. 104.
Pope, J.P., 1996a, Depositional cycles in the Bethany Falls Limestone member, Swope Formation (Pennsylvanian, Missourian), Madison County, Iowa [abstract ]: Missouri Academy of Science Transactions, v. 28.
Pope, J.P., 1996b, Depositional cycles in the Bethany Falls Limestone, Swope Formation (Pennsylvanian, Missourian), Taylor County, Iowa [abstract ]: Missouri Academy of Science Transactions, v. 29.
84 Texas Tech University, Graham Butler, December 2010
Posamentier, H.W., Jervey, M.T., and Vail, P.R., 1988. Eustatic controls on clastic deposition I conceptual framework, in C.K. Wilgus et al., Eds., Sea-level changes: an integrated approach: Society of Economic Paleontologists and Mineralogists Special Publication 42, p. 109-124. Posamentier, H.W., and Morris, W.R., Aspects of the stratal architecture of forced regressive deposits, in Hunt, D. & Gawthorpe, R.L. Eds. Sedimentary Responses to Forced Regressions, Geological Society, London, Special Publications 172 2000, p. 1-17.
Rankey, E.C., Bachtel, S.L., and Kaufman, J., 1999, Controls on stratigraphic architecture of icehouse mixed carbonate-siliciclastic systems: a case study from the Holder Formation (Pennsylvanian, Virgilian), Sacramento Mountains, New Mexico, Special Publication, Society for Sedimentary Geology, v. 63, p. 127-150.
Read, J.F., 1995, Overview of Carbonate Platform Sequences, Cycle Stratigraphy and Reservoirs in Greenhouse and Ice-house Worlds: SEPM Short Course No. 35, Part 1, p. 1-102.
Ross, C.A., and Ross, J.R.P., 1987, Late Paleozoic sea levels and depositional sequences: Cushman Foundation of Foraminiferal Research, Special Publication 24, p. 137- 168.
Rosscoe, S.J., 2005, Conodonts of the Desmoinesian (Middle Pennsylvanian) Lost Branch Formation, Oklahoma and Kansas, Department of Geosciences, Texas Tech University: Master Thesis.
Rosscoe, S.J., 2008, Idiognathodus and Streptognathodus species from the Lost Branch to Dewey sequences (Middle-Upper Pennsylvanian) of the Midcontinent basin, North America, Department of Geosciences, Texas Tech University: Doctoral Dissertation.
Scotese, C.R., and Golonka, J., 1992. Paleomap Paleogeographic Atlas, Paleomap Progress Report # 20, Dept. of Geology , University of Texas at Arlington.
Scotese, C.R., and Golonka, J., 1993, PALEOMAP Paleographic Atlas: Department of Geology, University of Texas, Arlington, p. 35.
Scotese, C.R., 2002, http://www.scotese.com, http://www.scotese.com/late.htm, (accessed May, 2009).
Soreghan, G., 1994. The impact of glacioclimatic change on Pennsylvanian cyclo- stratigraphy, Canadian Society of Petroleum Geologists, Memoir 17. p. 523-543.
85 Texas Tech University, Graham Butler, December 2010
Stover, S.G., 1992, Stratigraphy and depositional environment of the upper Bethany Falls limestone member, Farlinville North quarry, Linn County, Kansas, University of Kansas.
Van Wagoner, J.C., 1988, An overview of sequence stratigraphy and key definitions, in C.W. Wilgus et al., Eds., Sea level changes: an integrated approach. Society of Economic Paleontologists and Mineralogists Special Publication 42 p. 39-45.
Van Wagoner, J.C., Mitchum, R.M., Campion, K.M., and Rahmanian, V.D., 1990. Siliciclastic sequence stratigraphy in well logs, cores and outcrops. American Association Petroleum Geology, Methods Exploration, Ser., 7, p. 45.
Watney, W.L., French, J.A., and Franseen, E.K., Eds. 1989, Sequence stratigraphic interpretations and modeling of cyclothems in Upper Pennsylvanian (Missourian), Lansing and Kansas City Groups in eastern Kansas: Kansas Geological Society, Guidebook, 41st Annual.
Watney, W.L. French, J.A., Doveton, J.H., Youle, J.C., and Guy, W.J., 1995, Cycle hierarchy and genetic stratigraphy of middle and upper Pennsylvanian strata in the upper mid-continent, in Hyne, V, Ed., Sequence stratigraphy of the Mid- Continent: Tulsa Geological Society Special Publication No. 4, p. 141-192.
Wilke, N.A., 2000, Sequence stratigraphy of the Bethany Falls Limestone in eastern Kansas and western Missouri: Kansas Geological Survey, Open-file Report number 2000-28.
86 Texas Tech University, Graham Butler, December 2010
APPENDIX A
MEASURED SECTIONS
87 Texas Tech University, Graham Butler, December 2010
Figure A.1: Measured Section Key
88 Texas Tech University, Graham Butler, December 2010
Figure A.2: Winterset, Iowa Measured Section
89 Texas Tech University, Graham Butler, December 2010
Figure A.3: Utica, Missouri Measured Section
90 Texas Tech University, Graham Butler, December 2010
Figure A.4: KY Rd and Hwy 291, Independence, Missouri Measured Section
91 Texas Tech University, Graham Butler, December 2010
Figure A.5: 63rd St. and I-435, Kansas City, Missouri Measured Section
92 Texas Tech University, Graham Butler, December 2010
Figure A.6: Fireman’s Memorial, Kansas City, Missouri Measured Section
93 Texas Tech University, Graham Butler, December 2010
Figure A.7: Bannister Rd., Kansas City, Missouri Measured Section
94 Texas Tech University, Graham Butler, December 2010
Figure A.8: View High Dr., Kansas City, Missouri Measured Section
95 Texas Tech University, Graham Butler, December 2010
Figure A.9: MO Hwy 2, Missouri Measured Section
96 Texas Tech University, Graham Butler, December 2010
Figure A.10: Jingo Rd and Hwy 69, Kansas Measured Section
97 Texas Tech University, Graham Butler, December 2010
Figure A.11: 17 mi S. of Louisburg, Kansas Measured Section
98 Texas Tech University, Graham Butler, December 2010
Figure A.12: Farlinville Roadcut, Kansas Measured Section
99 Texas Tech University, Graham Butler, December 2010
Figure A.13: Mound City, Kansas Measured Section
100 Texas Tech University, Graham Butler, December 2010
Figure A.14: Xenia NW, Kansas Measured Section
101 Texas Tech University, Graham Butler, December 2010
Figure A.15: Bronson Quarry, Kansas Measured Section
102 Texas Tech University, Graham Butler, December 2010
APPENDIX B
OUTCROP PHOTOS
103 Texas Tech University, Graham Butler, December 2010
104 Texas Tech University, Graham Butler, December 2010
105 Texas Tech University, Graham Butler, December 2010
106 Texas Tech University, Graham Butler, December 2010
107 Texas Tech University, Graham Butler, December 2010
108 Texas Tech University, Graham Butler, December 2010
109 Texas Tech University, Graham Butler, December 2010
110 Texas Tech University, Graham Butler, December 2010
111 Texas Tech University, Graham Butler, December 2010
112 Texas Tech University, Graham Butler, December 2010
113 Texas Tech University, Graham Butler, December 2010
114 Texas Tech University, Graham Butler, December 2010
115 Texas Tech University, Graham Butler, December 2010
116 Texas Tech University, Graham Butler, December 2010
117 Texas Tech University, Graham Butler, December 2010
APPENDIX C
RESEARCH PHOTOS
118 Texas Tech University, Graham Butler, December 2010
Figure C.1: Photo of weathered, mottled, "peanut", zone at 17mi S. Louisburg outcrop. Scale increments = 25cm.
Figure C.2: Close up photo of weathered, mottled, "peanut", zone at View High Dr. outcrop.
119 Texas Tech University, Graham Butler, December 2010
Figure C.3: Close up of unweathered, mottled, "peanut", zone at Bronson Quarry outcrop. Lens cap = approx. 7.2cm.
Figure C.4: Photo of unweathered, mottled, "peanut", zone at Hwy 291 and KY Rd. outcrop. Geologist = approx. 183cm.
120 Texas Tech University, Graham Butler, December 2010
Figure C.5: Ooid filled scour at top of MO. HWY 2 outcrop. Note crossbedding within ooid package at top left. Ooids scouring into mottled wackestone facies. Scale = 10cm increments.
Figure C.6: Alternating shales and limestones at base of Hwy 435 & 63rd St. outcrop (Figure. A.4). Scale = 10cm increments.
121 Texas Tech University, Graham Butler, December 2010
APPENDIX D
GPS COORDINATES OF OUTCROPS
122 Texas Tech University, Graham Butler, December 2010
Table 1. Research Localities’ GPS Coordinates
01 – Winterset, Iowa...... 41°19’32.50”N 94°00’32.90”W 02 – Utica, Missouri...... 39°44’05.70”N 93°48’59.70”W 03 – KY Rd and Hwy 291, Independence, Missouri ...... 39°08’18.00”N 94°23’09.40”W 04 – 63rd St. and I-435, Kansas City, Missouri...... 39°00’43.60”N 94°29’57.50”W 05 – Fireman’s Memorial, Kansas City, Missouri...... 38°58’18.00”N 94°32’34.00”W 06 – Bannister Rd., Kansas City, Missouri...... 38°57’17.00”N 94°33’26.00”W 07 – View High Dr., Kansas City, Missouri...... 38°55’56.00”N 94°27’00.00”W 08 – MO Hwy 2, Missouri ...... 38°38’02.00”N 94°35’20.00”W 09 – Jingo Rd and Hwy 69, Kansas ...... 38°25’59.00”N 94°41’11.00”W 10 – 17 mi S. of Louisburg, Kansas...... 38°21’32.20”N 94°41’15.70”W 11 – Farlinville Roadcut, Kansas...... 38°15’05.00”N 94°51’16.00”W 12 – Mound City, Kansas...... 38°06’52.20”N 94°51’17.00”W 13 – Xenia NW, Kansas...... 38°01’23.35”N 95°00’49.00”W 14 – Bronson, Kansas ...... 37°51’47.00”N 95°03’00.00”W
123 Texas Tech University, Graham Butler, December 2010
APPENDIX E
CONODONT RAW DATA
124 Texas Tech University, Graham Butler, December 2010
125 Texas Tech University, Graham Butler, December 2010
126