Sequence Stratigraphy of Basal Oquirrh Group Caronates (Bashkirian) Thorpe Hills, Lake Mountain, Wasatch Front, Utah

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Theses and Dissertations

2011-11-10

Andrew D. Derenthal Brigham Young University - Provo

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Sequence Stratigraphy of the Basal Oquirrh Group (Bashkirian) Carbonates,

Thorpe Hills, Lake Mountain, Wasatch Front, Utah

Andrew D. Derenthal

A thesis submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of

Master of Science

Scott M. Ritter, Advisor Thomas H. Morris Brooks B. Britt

Department of Geological Sciences

Brigham Young University

December 2011

ABSTRACT

Sequence Stratigraphy of the Basal Oquirrh Group (Bashkirian) Carbonates,

Thorpe Hills, Lake Mountain, Wasatch Front, Utah

Andrew D. Derenthal

Department of Geological Sciences

Master of Science

The Early Pennsylvanian (Bashkirian/Morrowan) Bridal Veil Limestone of north- central Utah was deposited in the eastern portion of the rapidly subsiding Oquirrh basin. The 420 meter-thick Bridal Veil Limestone displays distinct cyclicity formed by stacked, meter to decameter scale high-frequency sequences and their constituent parasequences. Though no one ideal cycle may be defined for the Bridal Veil Limestone, each high- frequency sequence and parasequence contains a general shallowing upward trend that ranges from anaerobic to dysaerobic mudstone at the base to skeletal wackestone to mud- dominated packstone, capped by heterozoan grain-rich carbonates or siliciclastic tidalites. Cycles bounded by exposure surfaces, indicated by micro-brecciation, rhizoliths, laminated calcite or silica crusts, rip-up clasts, centimeter-scale teepee structures, and/or pronounced erosional relief are termed high-frequency sequences. Those bounded by marine flooding surfaces are defined as parasequences. Thusly defined, the Bridal Veil Limestone is divided into 25 high-frequency sequences designated BVL-1 through BVL- 25. Overall, two distinct sets of high-frequency sequences may be observed in the Bridal Veil Limestone. Sequences comprising the lower half of the formation (BVL-1 through BVL-12) are thicker, muddier, and less sand-prone than sequences in the upper half of the formation (BVL-13 through BVL-25), indicating an overall change in oxygenation, depositional texture, and accommodation upward in the section. Tracing of key beds and surfaces between the Thorpe Hills, Lake Mountain, and the Wasatch Range (spanning a distance greater than 50 miles) reveals that deposition was remarkably uniform across the southeastern part of the Oquirrh basin which we herein designate the Bridal Veil sub-basin and distinct from coeval formations in the southern Oquirrh basin, Ely basin, and Wyoming shelf. Mudstone and wackestone textures comprise a large portion of the formation by volume. Grain-rich carbonates are almost exclusively heterozoan in composition, indicating that the sub-basin was subphotic to aphotic through Early Pennsylvanian time.

Acknowledgements

I am deeply indebted to all those who assisted in the completion of this project. I owe special thanks to Dr. Scott Ritter, who not only offered help and expertise, but also, friendship and counsel throughout my undergraduate and graduate endeavors at Brigham Young University. I doubt I will meet another person who is so generous in giving of his time and talents and who displays such a love for teaching and learning. I would also like to thank Dr. Tom Morris, Dr. Brooks Britt, and Dr. Eric Christiansen for their input to the study. Of my fellow students and friends, I thank Chris Spencer, Kevin McGuire, Corey Dong, Sean Derenthal, and Christian Derenthal for assistance in field work. The research for this project was made possible by generous funding from Dr. Scott Ritter. Thank you to my wife, Tracy, an elect woman, for her patience and strength, and to my family.

iii

Table of Contents

INTRODUCTION ...... 1 BACKGROUND AND GEOLOGIC SETTING...... 2 METHODS ...... 3 MICROFACIES DESCRIPTIONS ...... 4 MF 1: Anaerobic Mudstone ...... 4 Description ...... 4 Interpretation ...... 5 Occurrence ...... 5 MF 2: Dysaerobic Spiculite Mudstone ...... 5 Description ...... 5 Interpretation ...... 6 Occurrence ...... 6 MF 3: Dysaerobic Sparse Skeletal Wackestone ...... 7 Description ...... 7 Interpretation ...... 7 Occurrence ...... 7 MF 4: Aerobic Mudstone to Sparse Skeletal Wackestone ...... 8 Description ...... 8 Interpretation ...... 8 Occurrence ...... 9 MF 5: Skeletal Wackestone ...... 9 Description ...... 9 Interpretation ...... 9 Occurrence ...... 9 MF 6: Mud-dominated Skeletal Packstone ...... 10 Description ...... 10 Interpretation ...... 10 Occurrence ...... 11 MF 7: Wackestone Caprock ...... 11 Description ...... 11 Interpretation ...... 11 iv

Occurrence ...... 11 MF 8: Skeletal Packstone Caprock ...... 12 Description ...... 12 Interpretation ...... 12 Occurrence ...... 13 MF 9: Mixed Grain Packstone to Grainstone Caprock ...... 13 Description ...... 13 Interpretation ...... 13 Occurrence ...... 14 MF 10: Mixed Siliciclastic/Carbonate Tidalite...... 14 Description ...... 14 Interpretation ...... 14 Occurrence ...... 15 MF 11: Sandstone ...... 15 Description ...... 15 Interpretation ...... 16 Occurrence ...... 17 SIGNIFICANT SURFACES ...... 17 Exposure Surfaces ...... 17 Flooding Surfaces ...... 18 Regressive Surfaces of Marine Erosion ...... 19 SEQUENCE STRATIGRAPHY ...... 20 Description of Sequences ...... 21 HFS BVL-1 through BVL-12 ...... 22 HFS BVL-1 ...... 22 HFS BVL-2 ...... 23 HFS BVL-3 ...... 24 HFS BVL-4 ...... 24 HFS BVL-5 ...... 24 HFS BVL-6 ...... 25 HFS BVL-7 ...... 25 HFS BVL-8 ...... 25 HFS BVL-9 ...... 26 HFS BVL-10 ...... 26 v

HFS BVL-11 ...... 26 HFS BVL-12 ...... 27 HFS BVL-13 through BVL-25 ...... 27 HFS BVL-13 ...... 27 HFS BVL-14 ...... 28 HFS BVL-15 ...... 28 HFS BVL-16 ...... 28 HFS BVL-17 ...... 29 HFS BVL-18 ...... 29 HFS BVL-19 ...... 29 HFS BVL-20 ...... 30 HFS BVL-21 ...... 30 HFS BVL-22 ...... 30 HFS BVL-23 ...... 31 HFS BVL-24 ...... 31 HFS BVL-25 ...... 31 FACIES MODEL...... 32 LACK OF PHOTOZOAN COMPONENTS ...... 35 CONCLUSIONS...... 36 REFERENCES ...... 38 FIGURES ...... 42 Figure 1 ...... 43 Figure 2 ...... 43 Figure 3 ...... 44 Figure 4 ...... 45 Figure 5 ...... 45 Figure 6 ...... 52 Figure 7 ...... 53 Figure 8 ...... 54 Figure 9 ...... 55 Figure 10 ...... 56 Figure 11 ...... 57 Figure 12 ...... 59 Figure 13 ...... 59 vi

Figure 14 ...... 60 APPENDIX A ...... 62 Thin Section Descriptions and Point Counts ...... 62 APPENDIX B ...... 68 Thorpe Hills Section Unit and Microfacies Thickness ...... 68 APPENDIX C ...... 76 Thin Section Images ...... 76

INTRODUCTION

The Oquirrh Group of north-central Utah comprises nearly 7,000 m (Hintze and

Kowallis, 2009) of Pennsylvanian and Permian strata deposited in a rapidly subsiding intracratonic depocenter known as the Oquirrh basin. The study of Oquirrh Group strata dates back to Spurr’s (1895) economic assessment of the Mercur mining district.

Subsequent workers have focused on the stratigraphic nomeclature (Bissell, 1962;

Nygreen, 1958; Welsh and James, 1961; Tooker and Roberts, 1970) and biostratigraphy

(Tooker and Roberts, 1970; Davis, 1994) of the Oquirrh Group in its type locality

(Oquirrh Mountains). Halting efforts to understand the depositional environments of this thick pile of late Paleozoic strata include studies by Alexander, (1978), Chamberlain and

Clark, (1973), Jordan, (1979), Jordan (1981), Jordan and Douglas (1980), and Konopka,

(1982). Sequence stratigraphic analysis of the group has begun only recently with Shoore and Ritter’s (2007) detailed study of the Bashkirian (Fig. 1) Bridal Veil Limestone in the vicinity of Provo, Utah. This study extends the analysis of the Bridal Veil Limestone westward from its type locality in the central Wasatch Mountains and indicates that the sequence architecture and depositional conditions first studied in the Wasatch Range are remarkably persistent throughout a 75 km-wide portion of the eastern Oquirrh basin that we herein call the Bridal Veil sub-basin. In this paper we describe the fundamental depositional and sequence stratigraphic patterns that define this sub-basin and develop a depositional model that accounts for the predominance of heterozoan carbonate deposition therein during Bashkirian time. 2

BACKGROUND AND GEOLOGIC SETTING

The Bridal Veil Limestone was formally named by Baker and Crittenden (1961), and represents the lower 420 m of the Oquirrh Group in the central Wasatch Range. This unit underlies the chiefly siliciclastic Butterfield Peaks Formation (over 8,000 m), and disconformably overlies the Late Missippian to earliest Pennsylvanian Manning Canyon

Shale (Hintze and Kowallis, 2009). In the Early Pennsylvanian, the Bridal Veil

Limestone represented a shallow carbonate shelf on the east side of the rapidly subsiding

Oquirrh basin (Fransom, 1950; Alexander, 1978) bounded on the west by the Antler

Uplift and to the east by the Round Valley shelf (Davis, 2011)) (Fig. 2).

The focus area for this study was the Thorpe Hills near Fairfield, Utah (Fig. 3) where basal Oquirrh carbonates are well exposed. The west side of the Lake Mountains provided good exposures of Bashkirian strata located approximately midway between the

Thorpe Hills and the Wasatch Mountains. Basal Oquirrh Group carbonates in the Thorpe

Hills and Lake Mountains have been assigned most recently to the West Canyon (Biek,

2004 and Biek et al., 2009). Nygreen (1958) originally named the West Canyon

Limestone based upon exposures in West Canyon located a few miles northwest of Cedar

Fort, Utah and 13 miles north of the Thorpe Hills. A comparison of Nygreen’s (1958) published West Canyon stratotype with strata described herein reveals that strata in the

Thorpe Hills and Lake Mountains are more closely aligned with the type Bridal Veil

Limestone. Consequently, Bashkirian strata in these two localities are assigned to the

Bridal Veil Limestone Member of the Oquirrh Group. 3

METHODS

In the Thorpe Hills, the Bridal Veil Limestone comprises over 430 meters of cyclically bedded limestone and fine sandstone. Owing to faulting, a composite Bridal

Veil section was pieced together from eight partial sections stitched together using easily traceable key beds. A composite section of similar thickness and lithology was measured on the west face of Lake Mountain. Oriented samples were collected from each bed in the Thorpe Hills. Field notes were taken for each section. The resulting composite

sections were drafted using Adobe Illustrator. 148 standard petrographic thin sections

were prepared from a representative suite of these samples and analyzed using a Nikon

Y-FL petrographic microscope. 98 of these were subjected to a 300 point count to

determine relative percentage of constituents and to delineate microfacies groupings.

For field and petrophysical descriptions, carbonate textures are defined in this

study by Dunham (1962) and modified to include a distinction between mud-dominated

and grain-dominated packstones, (Lucia, 1995) (Fig. 4).

Microfacies, as defined by Flügel (2004), is the total of all sedimentological and paleontological data which can be described and classified from thin sections, peels, polished slabs, or rock samples. To this end, point counts were performed on 98 thin sections to aid in defining the parameters for microfacies. 300 points were measured for each with 21 measurable components including skeletal grains, non-skeletal carbonate grains, quartz sand/silt, and primary porosity. Cluster analysis using PAST software

(Paleontological Statistics) was performed on the 21 by 98 data set, but failed to reveal meaningful clusters (microfacies). Better microfacies groupings were derived from a subjective evaluation of all slides, this time taking into account the depositional textures, 4

rather than the point-counted compositional attributes (Fig. 5). These resulting 11

microfacies types (described below) were used to identify facies stacking patterns in the

Thorpe Hills section (Fig. 6). 88.8% of the overall Thorpe Hills section was assigned a microfacies type based upon thin section petrography (colored beds in Figure 6). The

other 11.2% of the section (non-colored beds in Figure 6) were left unassigned due to

lack of thin sections for those units.

MICROFACIES DESCRIPTIONS

The Bridal Veil Limestone is comprised of a limited array of chiefly heterozoan

carbonate microfacies that vary in both grain composition and texture. The stacking

patterns created by assigning microfacies to successive stratigraphic units reveal that the

Bridal Veil Limestone is comprised of meter- to decameter-scale, coarsening upward

“cycles”. These genetic units grade from laminated to semi-laminated carbonate

mudstones (MF 1-4) in the lower part to skeletal or non-skeletal packstone and/or

sandstone (MF 5-11) in the upper part. The coarse-grained caprock facies occurs directly

below a flooding surface, a surface of subaerial exposure, or a thin marine sandstone bed

that displays evidence of exposure in the upper part. The identification of stacking

patterns defined by the following microfacies is instrumental in determining the sequence

hierarchy of the Bridal Veil Limestone.

MF 1: Anaerobic Mudstone

Description:

This microfacies is comprised of laminated mudstone and silty mudstone (Fig.

7A). The dominant skeletal constituents are rare to common monaxon demosponge (0.3-

23.3%) spicules and microbioclasts (0.6-6.6%) of echinoderms and other degraded 5

skeletal components. Spicules up to 1 mm long are typically oriented parallel to bedding.

Angular quartz silt and fine sand comprise up to 8.7% of the rock. Microbioclasts and

quartz silt are frequently concentrated in grain-rich laminae separated by mud-rich laminae.

In the field, these rocks typically comprise covered to partially covered slopes that

are laterally continuous along the outcrop. Where they are exposed, mostly at the base of

the Thorpe Hills section, they weather light tan to light gray. On fresh surfaces, these

rocks are dark gray to black. Laminations are more evident on the weathered surface

where quartz-rich laminae have been etched in relief.

Interpretation:

This fine-grained microfacies represents the deepest water conditions in the Bridal

Veil sub-basin. The paucity of skeletal grains, dark color, and preservation of laminae

indicate anaerobic conditions that were inhospitable to bottom-dwelling invertebrates as well as infaunal organisms. Microbioclasts present in this microfacies, most likely came from higher up on the shelf, as did the occurrence of skeletal grain-rich stringers, likely representing distal turbidity flows.

Occurrence:

This lithology is the most abundant microfacies (36.4% by volume) in the Bridal

Veil Limestone. It is typically found at the base of shallowing-upward, high-order cycles.

MF 2: Dysaerobic Spiculite Mudstone

Description: 6

The main distinction between this and the preceding microfacies is the presence

of disrupted laminae. Like the anaerobic mudstone microfacies, these units contain

limited skeletal grains, mostly composed of monaxon sponge spicules (< 21.0%) (Fig.

7B). The major constituent is carbonate mud (70.7-97.0%,) and thin sections commonly contain angular quartz silt (< 19.3%). Microbioclasts (< 2.6%) and peloids (< 8.7%) are minor constituents. Microbioclasts, if identifiable, are comprised of echinoderms, bivalve, and brachiopod fragments. Whole and disarticulated ostracode shells may be present.

On outcrop, rocks of this microfacies typically weather to covered to partially covered slopes. These mudstones weather tan-gray to a light orange color, and on a fresh surface are very dark gray to black in color. On outcrop, some laminations may be visible as well as vertical and horizontal thumb-sized burrows (Fig. 7D).

Interpretation:

Rocks of this microfacies are interpreted to represent deposition in relatively deep dysaerobic water. Microbioclasts and occasional peloids are thought to have been transported by turbidity currents from higher up on the shelf. Dysaerobic conditions are suggested by the partial disruption of primary laminae, indicating the presence of a limited or intermittent infauna.

Occurrence:

Rocks of this type are typically found at the base of asymmetric cycles. They often overlie anaerobic mudstones, and they are found below more skeletal-rich ledges.

This microfacies is the second most abundant lithology in the formation (32.3%). 7

MF 3: Dysaerobic Sparse Skeletal Wackestone

Description:

This microfacies exhibits rocks that are also composed mostly of carbonate mud

(51.7-95.0%) with only relict bedding (Fig. 7C). Texturally defined in a range from mudstones to sparse wackestones, these units differ from the preceding dysaerobic microfacies in that there is a greater percentage of skeletal grains, though they are still limited. Monaxon sponge spicules, generally aligned with disrupted bedding, are common (1.7-32.3%), and are accompanied by rare, whole skeletal grains (< 9.3%) including crinoids, echinoderms, bivalves, brachiopods, and bryozoans. Microbioclasts are rare (< 1.7%), and angular quartz silt ranges from trace amounts to 28.0% of the rock.

In outcrop, these units weather light gray to tan, fresh faces are often black to dark gray, and they infrequently display disrupted laminations. Commonly these rocks are covered to partially covered slopes. Sparse whole brachiopods, crinoids, or bryozoans may be evident where outcrop is available.

Interpretation:

This microfacies represents the transition from deeper, dysaerobic water into shallower, slightly more oxygenated water. Though some of the skeletal grains in this microfacies may have been transported from higher up on the shelf, many of the whole fossils are believed to have lived in situ. Oxygen levels are high enough at this depth to allow for disruption of the original bedding by a limited infauna and to sustain some marine biota, but low enough to limit their diversity and abundance.

Occurrence: 8

As with the mudstones of the previous two microfacies, this lithology is found in the recessive lower portion of marine parasequences. These microfacies comprise 6.5% of the Thorpe Hills Section.

MF 4: Aerobic Mudstone to Sparse Skeletal Wackestone

Description:

This microfacies is distinguished from preceding mud-dominated microfacies by the lack of physical internal bedding. Rare skeletal elements may include sponge spicules, echinoderms, crinoids, brachiopods, ostracodes, and bryozoans. Quartz silt, peloids, and microbioclasts are also present (all less than 2.0%) (Fig. 7E).

In outcrop, these limestones are massive, dense, and generally lack any visible skeletal grains. They are light gray to tan on weathered surfaces, and dark gray on fresh surfaces. There are no laminations evident in outcrop, but 2-3 cm-diameter, chert- replaced Thallasanoides burrows are common (Fig. 7F). Though often partially covered, in some cases where the rock is very dense, it may form a discrete ledge. Often it is found at the base of a package of more prevalent ledges.

Interpretation:

The mudstones of this microfacies are interpreted to represent deep water deposition. As with the previous microfacies, these rocks represent low light conditions, but oxygen levels have increased enough for marine biota to completely obliterate all forms of bedding. The low-energy environment is attributed to deposition below storm wave base. Skeletal grains, however, are still rare, indicating this remains a transitional microfacies from deep water into shallower, skeletal grain-rich wackestones and packstones. 9

Occurrence:

Rocks of this microfacies, if present, typically occur below cycle-capping facies within individual high-order cycles. Of the section, this grouping only represents 2.8%

by volume.

MF 5: Skeletal Wackestone

Description:

These textural wackestones contain a range (4.6-49.3%) of whole to broken heterozoan skeletal components that is dominated by brachiopods (0.7-30.3%), bryozoans

(< 23.7%), and crinoids (< 16%) (Fig. 8A). Echinoid spines, bivalves, gastropods, conodont elements, ostracodes, sponge spicules, foraminifera, and trilobites comprise less than 10% of rock by volume. Non-skeletal grains may include angular quartz silt (0-

5.3%), peloids (0-2.0%), and intraclasts (0-5.3%). These rocks are devoid of bedding and sometimes show a muddy, clotted texture in thin section.

In outcrop, these rocks weather medium to light gray, and on a fresh surface they appear dark gray. They are massive and may contain whole brachiopods, crinoids, and bryozoans set in muddy matrix. These units weather to a recessive profile.

Interpretation:

This microfacies is interpreted to represent marine deposition, below storm wave base in oxygenated water that supports a full complement of heterozoan invertebrates and a vigorous infauna. The absence of photozoan skeletal components indicates sub-photic conditions.

Occurrence: 10

These rocks occur at the base of parasequences as a trangressive unit or in the middle as part of the shallowing-up portion. They may underlie more grain-rich cap rocks. This microfacies represents 2.8% of the section.

MF 6: Mud-dominated Skeletal Packstone

Description:

Thin sections of this microfacies show a diverse skeletal assemblage (40.0-56.2%) comprised chiefly of crinoids (7.7-25.3%) and brachiopods (13.0-30.3%) (Fig. 8B).

Other common grains include echinoids, bivalves, gastropods, bryozoans, conodont elements, ostracodes, sponge spicules, foraminifera, trilobites, and shallow-water algae

(Asphaltina) (each less than 10.0% of rock volume). Mud (42.7-60.0%) is massive and lacks sedimentary structures. Non-skeletal grains include peloids, angular quartz silt, and intraclasts (each less than 5.0%).

On outcrop, these units form the basal portion of massive ledges or cliffs. Whole brachiopod and crinoid columnals may be seen (Fig. 8C), however, many units are very fine grained with few readily discernable fossils. Color in these rocks ranges on weathered surface from light to dark gray, and on a fresh surface from medium to dark gray.

Interpretation:

This microfacies is interpreted to represent marine deposition between normal wave base and storm wave base. Only sporadic energy allows for the carbonate mud to be winnowed from between the skeletal grains. Light and oxygen levels are high enough to promote a diverse assemblage of skeletal grains and a vigorous infauna capable of destroying original bedding laminations. 11

Occurrence:

Where present, rocks of this microfacies just underlie parasequence cap rocks.

However, this microfacies only represents 0.2% of the assigned section.

MF 7: Wackestone Caprock

Description:

This microfacies consists of textural wackestones. Overall, they are dominated by

carbonate mud (62.0-89.3%) but contain a significant percentage of skeletal grains (10.3-

32.3%) (Fig. 8D). The skeletal portion may consist of brachiopods (< 22.0%), sponge

spicules (< 10.3%), crinoids (< 9.7%), echinoids (< 4.7%), and smaller percentages (all

less than 2.0%) of bivalves, gastropods, bryozoans, ostracodes, foraminifera, and

trilobites. Non-skeletal components include quartz silt (< 13.3%), peloids (< 3.3%), and

intraclasts (< 0.3%). These rocks are devoid of laminations, and like their non-caprock

counterparts, may display a mottled, clotted texture in thin section.

In outcrop, these units display a recessive profile or form discrete ledges. On a

weathered surface these wackestones appear medium to light gray, and on a fresh surface

they appear dark gray. They are massive and may reveal whole fossils of brachiopods,

crinoids, and bryozoans set in muddy matrix (Fig. 8F).

Interpretation:

This microfacies is interpreted to represent marine deposition, below storm wave base. Light and oxygen are plenty enough for a heterozoan fauna in fully bioturbated carbonate mud. The abundance of carbonate mud is due to the low energy environment.

Occurrence: 12

This microfacies caps underdeveloped parasequences that do not shallow enough for more grain-rich units to be deposited. It only represents 0.8% of the assigned section.

MF 8: Skeletal Packstone Caprock

Description:

This microfacies contains rocks that are texturally described as packstones. They display a range of carbonate mud (10.0-62.3%) and grain-supported skeletals (34.6%-

75.7%) (Fig. 8E). The skeletal grains consist of crinoids (7.3-30%), brachiopods (7.3-

28.7%), bryozoans (1.3-14.7%), bivalves (< 7.3%), and minor amounts of echinoids, gastropods, conodonts, ostracodes, sponge spicules, foraminifera, trilobites, and shallow- water algae including Asphaltina (all less than 3.0%). Non-skeletal grains may consist of quartz silt (< 2.0%), peloids (< 1.7%), intraclasts (up to 1.0%), and trace amounts of ooids. No laminations are present in these rocks.

In outcrop, these units form the capping units dominating massive ledges or cliffs.

Whole fossils of crinoid and brachiopod may be seen, however, many units are very fine grained and few fossils are readily discernable (Fig. 8F). Color in these rocks ranges on weathered surface from light to dark gray, and on a fresh surface appear dark gray.

Interpretation:

This microfacies is interpreted to represent shallow marine deposition. The increased skeletal grain diversity indicates well-oxygenated, photic zone conditions. The range in carbonate mud indicates varying degrees of energy for this microfacies. Lower mud content represents higher energy conditions, most likely proximal to normal wave base. Higher mud content represents lower energy conditions, more likely deeper, nearing storm wave base. 13

Occurrence:

Units of this microfacies occur as parasequence caprocks. Though they are the

best exposed, the thickness of this microfacies as compared to deeper water is

significantly less at only 3.1%.

MF 9: Mixed Grain Packstone to Grainstone Caprock

Description:

These rocks are texturally described as packstones and grainstones. The

carbonate mud content is significantly less than that of the previous microfacies (1.3-

65.3%). In grain support, these rocks display a mixed assortment of both skeletal grains

and coated grains (Fig. 9A). Skeletal grains are diverse, but the majority of grains consist of crinoids (< 35%) and brachiopods (< 50%). Other skeletal grains may include

echinoids (< 10%), bivalves (< 5%), gastropods (< 5%), bryozoans (< 45%), foraminifera

(< 2%), trilobites (< 10%), and shallow water algae including Asphaltina (< 15%). Non- skeletal grains include ooids (0-25%), oncoids (0-40%) (Fig. 9B), intraclasts (0-10%), peloids (< 30%), and quartz silt (< 45%). These rocks are massive, devoid of bedding, and they occasionally display crossbedding visible in the thin section.

In outcrop, these rocks weather medium gray to light gray, and on a fresh surface they appear dark gray. Calcite or silica replaced brachiopods and crinoids are often visible on weathered surfaces, and overall, grains in relief may appear as fossil hash.

Large scale, low-angle cross beds may be visible in particularly grainy units.

Interpretation:

These rocks represent high-energy carbonate deposition. Diversity of fossils and lack of visible bedding indicate well oxygenated, photic zone conditions. An increased 14

percentage of photozoan assemblage grains, including coated grains (ooids, oncoids, and

peloids), shallow-water algae (Asphaltina), trilobites, gastropods, and foraminifera, all

indicate shallow, warm water conditions. Decreased mud content is due to winnowing by

waves.

Occurrence:

This lithology occurs as the capping unit of many parasequences. However, due

to thin bedding as compared to the thick accumulations of MF 1 and MF 2, it only

comprises 2.7% of the Thorpe Hills section.

MF 10: Mixed Siliciclastic/Carbonate Tidalite

Description:

Lithologically, the microfacies ranges from fine-grained quartz sandstone to silty lime mudstone with small admixtures of skeletal and non-skeletal carbonate grains (Fig.

9D). Lenses of pebble conglomerate occur in some horizons. Subangular quartz grains range from fine to very fine in size.

In outcrop, these units possess a striped appearance resulting from differential weathering of alternating quartz- and carbonate-rich laminae and cross-laminae (Fig. 9E-

F). They typically weather to orange-brown platy ledges and small cliffs. Ripple cross- laminae, herringbone structures, and dish-and-pillar water escape structures, are common sedimentary structures visible in outcrop.

Interpretation:

This microfacies is established for rocks deposited under peritidal conditions manifested chiefly by the presence of ripple cross-lamination, herringbone ripples, 15 crinkly lamination, planar laminae, and/or calcite-filled fenestrae (Fig. 9C). Sedimentary structures indicate high-energy, bi-modal flow, and intermittent exposure.

Occurrence:

This microfacies caps a limited number of parasequences and comprises 4.7% of the measured section.

MF 11: Sandstone

Description:

Approximately 9% of the Bridal Veil Limestone consists of tan and light-gray calcareous sandstone. Petrographically, these units are dominated by fine- to medium- size, angular to subrounded fine quartz sand (Fig. 10A). They contain from 5-25% calcareous material in the form of microbioclasts and abraded peloids. Quartz-dominated sandstone beds range from 0.20 to 6.0 meters in thickness and form continuous flat sand sheets that can be traced laterally for up to 50 km. Though volumetrically unimportant, these quartz sandstone beds are critical to regional correlation and recognition of sequence boundaries.

Thin sandstone beds (those under 1.0 meter in thickness) typically consist of a single set of low-angle tabular crossbeds bounded above and below by sharp, near- parallel surfaces (Fig. 10B-C). Thicker sandstone beds comprise a stacked succession of low-angle tabular crossbeds that are separated by truncation surfaces. Some thicker beds contain disrupted and recumbently folded laminae related to the fluid escape and gravity- driven soft-sediment deformation. The north to south orientation of crossbedding is remarkably uniform from sandstone bed to sandstone bed within individual sections and 16

between the three measured sections. With the exception of root molds (Fig. 10D-E), trace fossils are absent.

Basal contacts with underlying carbonate units are sharp, with or without a few centimeters of scour. Some sandstone beds overlie exposure surfaces and contain cemented lithoclasts of the underlying carbonate bed in the lower few centimeters.

However, in the majority of sheet sands, exposure features (rhizoliths (Fig. 10D-E), blackened seams (Fig. 10F), oxidation, and microbreccias) are instead associated with the upper contact.

Interpretation:

Quartz-rich sandstone beds within carbonate-dominated sections of Late

Paleozoic age are generally interpreted to have been deposited during lowstands of sea level by eolian processes and subsequently overprinted by marine processes during the ensuing rise of sea level (Mazzullo et al., 1985; Fischer and Sarntheim, 1988;

Goldhammer et al., 1991). This model explains the origin of sheet sands overlying exposure surfaces, but does not satisfactorily explain the origin of sheet sands that underlie exposure surfaces (several of the sandstones in the Bridal Veil Limestone). Nor do the majority of sandstones in the Bridal Veil contain glauconite and marine trace fossils, both of which were reported in sheet sands of the Paradox basin (Goldhammer et al., 1991).

Since most of the sandstone units in the Bridal Veil Limestone have exposure surfaces on their upper contact, they are interpreted to have been deposited during late falling stage. Wind-blown sands from the Wyoming shelf to the northeast inhibited 17

carbonate deposition, and resulted in the migration of wave-driven, straight-crested sand bars across the shelf.

Grammer et al. (2000) discussed the concept of a double cycle (siliciclastic cycle

overlain by a carbonate cycle), where basal sandstone beds are bounded above and below

by exposure surfaces. In such a case, lowstand, wind-blown, subangular to subrounded

quartz sand is reworked by marine waters during the ensuing transgression. As observed in the Paradox basin to the south, Grammer et al. (2000) implied double cycles with two shallowing-upward trends; one that occurs in the siliciclastics and one in the carbonates.

This may be the case for sandstone beds in high-frequency sequences BVL-5 and BVL-

10 (see below) in the Bridal Veil Limestone.

Occurrence:

When present, these sandstones overlie parasequence cap rocks, and they represent 8.7% of the assigned section.

SIGNIFICANT SURFACES

Recognition and interpretation of key surfaces is a critical step in subdividing the

Bridal Veil Limestone into genetic units and in understanding the effect of sea-level change on sequence architecture. Three types of genetically significant surfaces are common in the studied interval: exposure surfaces, flooding surfaces, and regressive surfaces of marine erosion (RSME). Each of these is described below.

Exposure Surfaces

Surfaces indicating subaerial exposure are a common feature of the Bridal Veil

Limestone in the study area. Twenty-three such surfaces are indicated by a combination of some or all of the following characteristics: micro-brecciation, rhizoliths, blackened 18

grains, sheet cracks filled with black calcite cements, blackened cement crusts,

oxidization, and/or rip-up clasts in the base of the overlying bed (Fig. 10D-F). Of the

twenty-three exposure surfaces, 19 are developed on grain-rich carbonate beds; the other

four are developed on the top of fine-grained quartz sandstones. These discontinuity

surfaces, which developed during lowstands of the Bashkirian seas, are used to subdivide

the Bridal Veil into high-frequency sequences (see below).

The duration of exposure for individual surfaces is difficult to evaluate as they fall

below the level of biostratigraphic resolution. Saller et al. (1999) relied upon the

intensity of early diagenesis and porosity evolution to infer the relative duration of

subaerial exposure in Pennsylvanian and Permian strata of the Permian basin. Estimates

ranged from 5000 years or less for surfaces showing little alteration to approximately

130,000 years for surfaces displaying extensive alteration. Alteration on Bridal Veil

exposure surfaces is limited to the upper few centimeters to decameters of subjacent beds

and is only moderately disruptive of depositional features suggesting relatively short-

lived exposure under arid to semi-arid conditions.

Flooding Surfaces

Surfaces across which there is evidence of an abrupt increase in water depth are

common in the Thorpe Hills section of the Bridal Veil Limestone. These are placed

where mud-dominated microfacies (microfacies 1 through 4, and infrequently wackestone-packstone transgressive units of microfacies 5 through 6) occur on top of

skeletal or mixed skeletal-coated grain wackestones, packstones, grainstones or

sandstones (microfacies 7 through 11) reflecting a “sudden” change from oxygenated,

invertebrate-rich bottom conditions to barren anaerobic/dysaerobic conditions. In the 19

field, flooding surfaces are generally located at the change from ledge-forming, grain-rich

limestone or quartz sandstone to slope-forming mudstone and wackestone. Where

exposed, the contact between the two contrasting microfacies is sharp with or without a

few centimeters of erosional relief. In cycles that do not display evidence of subaerial

exposure, marine flooding surface constitute boundaries between successive high-order

sequences (parasequences). Sixty marine flooding surfaces occur in the Thorpe Hills

section of the Bridal Veil Limestone.

Regressive Surfaces of Marine Erosion

Regressive surfaces of marine erosion (RSME’s) as described by Plint (2010) are common throughout the Bridal Veil Limestone. Plint (2010) used the term as applied to siliciclastic environments, though it was similarly described by Soreghan and Dickinson

(1994) as a “catch-down surface” applying both to siliciclastics and carbonates. RSME’s occur where a sharp, laterally extensive contact marks the abrupt transition from a mud-

prone facies (microfacies 1 through 5) below the surface to grain-rich facies (microfacies

8 through 11) above. Grain-filled burrows often extend downward into the muddier facies (Fig. 11).

This surface indicates that carbonate sedimentation lagged behind the development of accomodation space through deposition of the mud-rich transgressive and highstand systems tracts. Subsequent falling of sea level imposed high-energy conditions on the previously quiescent seafloor, resulting in minor scouring of muddy sediments and onset of grain-rich sedimentation. Burrowing organisms escaped the high-energy conditions by penetrating into the unlithified muds underlying the RSME, which burrows were filled with grain-rich sediments derived from overlying higher-energy deposits. 20

SEQUENCE STRATIGRAPHY

With minor revisions, this paper extends the geographic reach of the

nomenclature presented by Shoore and Ritter (2007) for the sequence hierarchy of the

Bridal Veil Limestone. New data from Lake Mountain and the Thorpe Hills indicate that

the Bridal Veil Limestone can be divided into 25 high-frequency sequences (HFS) based

upon the correlation of regionally persistent exposure surfaces and key beds.

Collectively, these contain a maximum of 80 parasequences (Fig. 12). These 25 HFS’s

fall within the Lower Absaroka I supersequence which begins at the lower Bashkirian

unconformity and ends at the upper kasimovian unconformity (Golonka and Kiessling,

2002).

The term high-frequency sequence refers to higher-frequency, unconformity-

bound sequences within higher-order depositional sequences (Kerans and Tinker, 1997).

HFS’s also are characterized by the attributes that make up depositional sequences,

including lowstand, transgressive, and highstand systems tracts and their component

parasequences. HFS’s and parasequences of the Bridal Veil Limestone are the equivalent

of fourth-order, icehouse, depositional parasequences as outlined by Goldhammer et al.

(1991).

In the Bridal Veil Limestone, 25 HFS’s are bounded by regionally persistent unconformities characterized by one or more of the following attributes: micro- brecciation, rhizoliths, laminated calcite or silica crusts, rip-up clasts, centimeter-scale teepee structures, pronounced erosional relief, and/or the presence of exposure at the base

or top of quartz-rich falling stage sheet sands. These HFS’s are composed of from one to

seventeen parasequences. Within parasequences, basal slope-forming mudstone and 21

wackestone (one or a combination of microfacies 1 through 4) grades upward into medium- to thick-bedded skeletal-coated grain packstone (microfacies 5 through 9). This vertical facies succession represents a shallowing-upward trend from low-energy to high.

Parasequences are bounded by marine flooding surfaces except in the case of the uppermost parasequence within each HFS, which is capped by an HFS boundary.

Maximum cycle duration and order of cyclicity is calculated by dividing the 6.4-million-

year duration of the Bashkirian Stage by the number of cycles in the Bridal Veil

Limestone. These simple calculations indicate that the HFS and parasequence cycles have an approximate average duration of 256,000 and 80,000 years, respectively.

HFS’s were correlated from the Wasatch Range to Lake Mountain and the Thorpe

Hills based on stratigraphic position, tracing of significant surfaces, lithology, placement within bed successions, character of basal and upper contacts, and/or the presence of selected beds with distinctive lithological attributes.

From the base to top, the HFS’s are labeled BVL-1 through BVL-25. HFS boundaries are labeled in accordance with the HFS that overlies them. Thus, HFS boundary BVL-1 is at the base of depositional HFS BVL-1, etc. Between these sections, parasequences cannot be confidently correlated, although the HFS’s are easily traced.

“Missing” parasequences may be a function of the lateral pinch-out of selected cycles between the three sections or they may be present, but concealed by regolith under covered slopes.

Description of Sequences

The parasequence composition and systems tracts of each of the 25 HFS’s are discussed below. 22

HFS BVL-1 through BVL-12

The lower 12 HFS’s of the Bridal Veil Limestone comprise a natural grouping in

that they are thicker, muddier, and less sand-prone than HFS’s in the upper half of the

formation. These lower 12 HFS’s have an average thickness of 22.4 meters, compared to

13.5 meters for the upper 11 HFS’s. Nearly 100% of the anaerobic mudstone facies occurs within this HFS grouping. However, only 25% of the quartz sheet sands in the

Bridal Veil Limestone are contained therein. These patterns indicate an overall change in oxygenation, depositional texture, and accommodation upward in the section.

HFS BVL-1

The basal sequence of the Bridal Veil Limestone is 30.1 meters thick and is comprised of two parasequences. The basal sequence boundary, which coincidently defines the Manning Canyon-Bridal Veil formational contact, is placed at the base of a

1.6 meter-thick, reddish (oxidized) calcareous sandstone bed that contains granule-size

lithoclasts in the upper part. This bed, which represents a thin siliciclastic parasequence,

marks the abrupt changes from siliciclastic rocks below to carbonate rocks above. The

upper 25 to 30 meters of the Manning Canyon Shale is comprised of ripple cross-

laminated fine quartz sandstone and silty black shale, the latter underlying covered

slopes. The 1.6 meter boundary bed reflects the lowstand influx of coarse quartz sand and

granules. This is directly overlain by 20 meters of anaerobic to dysaerobic mudstone

deposited during subsequent transgression and highstand of sea level. The falling stage

systems tract is represented by approximately 3 meters of platy, ripple cross-laminated

fine sand and fine carbonate packstone to grainstone. Fenestral and laminated

(stromatolitic) mudstone at the top of the sequence in the Thorpe Hills and at Cascade 23

Mountain indicates the widespread development of supratidal facies prior to exposure.

Laterally, BVL-1 increases in thickness to the east, from 30.1 meters in the Thorpe Hills

up to 40.5 meters in the Wasatch Range (Shoore and Ritter, 2004).

HFS BVL-2

HFS boundary BVL-2 is developed upon sandy tidal deposits that constitute the

upper meter or more of HFS BVL-1. In the Thorpe Hills and at Lake Mountain, evidence

of exposure (incipient rhizoliths) is subtle. At Cascade Mountain, however, sequence

boundary BVL-2 is characterized by up to 1 meter of erosional relief. HFS BVL-2 is

lithologically distinct for two reasons. First, it is one of two HFS’s comprised chiefly of

siliciclastic beds (very fine to medium quartz arenite) and secondly, it was largely or

completely removed in selected areas during the subsequent lowstand of sea level. As a

result, sequence BVL-2 ranges in thickness from 0 to 15 meters. The constituent

sandstone beds are characterized by ripple cross-lamination, herringbone bedding, and thin lenses of skeletal debris (tidal channel fill) suggesting deposition under shallow marine to peritidal conditions. Incised valleys up to 15 meters deep were cut into BVL-2 in the Thorpe Hills, Provo Canyon, and Rock Canyon coincident with the development of sequence boundary BVL-3. The orientation of these paleovalleys is difficult to ascertain given the limited outcrop. HFS BVL-2 retains a thickness of 15 meters in the interfluve

areas (Lake Mountains, Cascade Mountain between Provo Canyon and Rock Canyon).

The predominance of quartz sandstone in BVL-2 and the degree of subsequent erosion

indicates that sea level was at a minimum during and after deposition of this HFS,

relative to the rest of the Bridal Veil Limestone. 24

HFS BVL-3

Much of BVL-3 constitutes the infilling of the valleys incised into the underlying

HFS. One parasequence makes up this HFS, and it contains up to 22.2 meters of

anaerobic mud that bring the previous relief back to fill-level. A thin, skeletal packstone

with rip-up clasts and rhizoliths caps this HFS. The maximum thickness of this HFS is

20.1 meters, 11.8 meters, and 22.2 meters in the Thorpe Hills, Lake Mountain, and the

Wasatch Range, respectively. The incision and subsequent filling of paleovalleys

represents the lowstand and transgressive systems tracts of a low-order (third-order) cycle

referred to as LOS (lower order sequence) 2 of Shoore and Ritter (2007).

HFS BVL-4

BVL-4 is the thickest of the HFS’s in this section and constitutes the maximum

flooding portion of LOS 2. It contains 17 parasequences and is bounded by exposure

surfaces BVL-4 and BVL-5. Parasequences within BVL-4 range from approximately 1

to 22 m. Mostly underlain by anaerobic mud, caprocks in this HFS are wackestone,

tidalite, mixed skeletal-coated grain packstone, and skeletal packstone, with skeletal

packstones making up the majority. This HFS is capped by a 1 meter sandstone unit with

black cement laminated crust, brecciation, and blackened grains, indicating exposure in

its upper 5 cm. Thickest in the Thorpe Hills at 83.5 meters it thins eastward to 50.1 meters in the Wasatch Range.

HFS BVL-5

BVL-5 is composed of a single 2.6 to 3.2 meter-thick quartz sandstone cycle bounded above and below by exposure surfaces as discussed by Grammer et al. (2000).

It is characterized by low-angle tabular crossbeds bounded above and below by sharp 25

parallel surfaces, and is interpreted to represent marine-reworked eolian sands derived

from the Bashkirian Wyoming shelf.

HFS BVL-6

This HFS is comprised of a single parasequence that is dominated by anaerobic mud. Only partially exposed in the Thorpe Hills, this HFS is capped by a thin tidalite unit. BVL-6 is 23.0 m, 7.5 m, and 14.3 m in the Thorpe Hills, Lake Mountain, and

Wasatch Range, respectively.

HFS BVL-7

BVL-7 is composed of three parasequences. Nearly 2 m of wackestone and packstone at the base of this HFS make up the transgressive systems tract. Dysaerobic mud and two thin ledges lay on top, followed by a thick 5.5 m rippled-laminated tidalite

package. Laterally, this HFS measures 11.2 m, 17.0 m, and 9.0 m in the Thorpe Hills,

Lake Mountain, and Wasatch Range, respectively.

HFS BVL-8

This HFS fills in the erosional topography from the previous depostional HFS. At

its base is a 1.2 m wackestone to packstone unit that comprises the transgressive systems

tract. Containing five parasequences, this HFS is mostly composed of anaerobic

mudstone. Each parasequence is capped by relatively thin (0.4-0.8 m) skeletal packstone

beds. This HFS is 19.8 m, 30.5 m, and 26.7 m in the Thorpe Hills, Lake Mountain, and

Wasatch Range, respectively. 26

HFS BVL-9

BVL-9 contains seven parasequences. At its base is a 1.2 meter-thick sandstone

overlain by 2.5 m of anaerobic mudstone that is capped by a mixed skeletal-coated grain

packstone. The following parasequence introduces a thick unit (5.5 m) of dysaerobic

mudstone with large (5 cm diameter) vertical burrows. Capped by a wackestone and a

flooding surface, these units are overlain by more anaerobic mudstone. Mudstone and

skeletal packstone repeat three more times to complete this HFS. The thickness of this

HFS is consistent from Thorpe Hills to Lake Mountain measuring 30.1 m and 31.5 m, respectively. However, it is only half as thick in the Wasatch Range measuring 16.4 m.

HFS BVL-10

One parasequence and one unit comprise BVL-9. It is solely composed of a sandy, crossbedded, mixed skeletal-coated grain packstone. This sandy, laterally variable unit is seen at Lake Mountain and in the Wasatch Range grading up into muddier units that are capped by an exposure surface. Only 3.3 m in the Thorpe Hills, it thickens to the east, reaching 8.9 m in the Wasatch Range.

HFS BVL-11

BVL-10 contains three parasequences. The first is a wackestone to packstone facies, a 1.4 m thick transgressive unit. The two parasequences that follow are uniform in thickness; however the first is mainly composed of mudstone that has no preserved laminations. It is capped by a crossbedded skeletal packstone, followed by a flooding surface, anaerobic mudstone, and finally capped by 2.1 m of tidal laminites, featuring dish-shaped dewatering structures and grain-filled channels. The measured thickness of 27

this HFS is 16.4 m, 13.1 m, and 28.6 m in the Thorpe Hills, Lake Mountain, and Wasatch

Range, respectively.

HFS BVL-12

This HFS is composed of one parasequence. Over 7 m of anaerobic mudstone are

in the lower part, capped by falling-stage massive, skeletal wackestones. An RSME

marks the transition into a thick, laterally continuous sandstone (6.0 m) unit. This

sandstone unit seems to mark a transition into thinner HFS’s, more sandstones, and less

anaerobic mudstone. The upper 20 cm of the sandstone features displacing cements,

pebbles, and black calcite crusts indicating prolonged exposure. This HFS is relatively

consistent laterally, measuring 16.6 m, 17.1 m, and 10.8 m in the Thorpe Hills, Lake

Mountain, and Wasatch Range, respectively.

HFS BVL-13 through BVL-25

The upper 11 third-order HFS’s of the Bridal Veil Limestone are consistent in that

they are dominated by dysaerobic mudstone (microfacies 2 and 3), contain more frequent

ledges, and contain 75% of the sandstone units despite representing half of the entire

section. Average HFS’s are not as thick as that of the lower half of the section at 13.5

meters.

HFS BVL-13

The base of this HFS is a thin transgressive packstone containing abundant

brachiopods. This packstone is overlain by nearly 12 meters of dysaerobic mudstone.

Two closely-spaced, skeletal packstone ledges cap the two parasequences of BVL-12.

The second of the two parasequences is ultimately capped by a thin (0.4 m), sandstone 28

unit. Thickest in the Thorpe Hills, measuring 16.2 m, this HFS thins to the east,

measuring 7.8 m in the Wasatch Range

HFS BVL-14

Three, evenly spaced parasequences make up BVL-13. Each of the parasequences has dysaerobic mudstone at its base, though only the first two coarsen upward into skeletal packstones. The second and third parasequences are capped by sandstone units. The uppermost sand in this HFS is 3 m thick, and contains displacing cements in its upper 15 cm. Black, calcitic crusts and rhizoliths also indicate prolonged exposure and the cap of this HFS. This HFS thickens to the east, measuring 17.8 m and

22.5 m in the Thorpe Hills and Wasatch Range, respectively.

HFS BVL-15

This HFS has a 1.5 m transgressive packstone at its base. It is composed of two parasequences. The first parasequence is mostly composed of dsyaerobic mudstone with a tidalite caprock. The second is also mostly composed of dyaserobic mudstone, but contains a sandstone unit at the top with black chert and exposure features on its surface.

Thickness of this HFS is relatively consistent laterally, measuring 15.8 m, 16.9 m, and

12.0 m in the Thorpe Hills, Lake Mountain, and Wasatch Range, respectively.

HFS BVL-16

BVL-16 contains two parasequences. The first is dominated by dysaerobic mudstone with a capping skeletal packstone. The second has a much more even ratio between mudstone and ledge-forming units. The cap to the second parasequence and the

HFS is a silty tidalite. Thickness of this HFS is relatively consistent laterally, measuring 29

9.7 m, 12.8 m, and 10.0 m in the Thorpe Hills, Lake Mountain, and Wasatch Range,

respectively.

HFS BVL-17

This HFS is characteristic of the upper half of the section in that it is nearly half dysaerobic mudstone and half ledge-forming grainy, carbonates. Four parasequences

make up BVL-17. Each contains dysaerobic mudstone at its base and is capped by a

skeletal packstone. The fourth differs in that it lacks a skeletal packstone, but is

terminated by low stand sandstone that begins the subsequent HFS’s. This HFS ranges in

thickness, measuring 10.8 m, 31.3 m, and 21.6 m in the Thorpe Hills, Lake Mountain,

and Wasatch Range respectively.

HFS BVL-18

BVL-18 is a relatively thin HFS, containing two parasequences. It has low-stand sandstone unit at its base, overlain by a thin whole brachiopod bearing carbonate ledge, representing the thin, transgressive systems tract of this HFS. The falling stage is mostly composed of dysaerobic mudstone. An RSME marks the transition from dysaerobic mudstone to a falling stage sandstone unit, containing exposure features on its surface.

This HFS thickens to the east, measuring 6.2 m and 10.2 m in the Thorpe Hills and

Wasatch Range, respectively.

HFS BVL-19

This HFS is comprised of two parasequences. The first is mainly composed of dysaerobic mudstone that grades upwards into fully aerobic mudstone. It is capped by 3 m of tidalite ledge formers. The second parasequence contains dysaerobic mudstone at 30

its base. The mudstone facies stops abruptly at an RSME, marking a transition into

falling-stage sandstone with evidence of exposure on top. This HFS thins laterally,

measuring 19.0 m in the Thorpe Hills and 7.5 m in the Wasatch Range.

HFS BVL-20

This HFS is composed of three parasequences. A 1 m, oncoid bearing, recessed carbonate ledge forms the base of this HFS and represents the transgressive systems tract.

A thin packstone caps the first parasequence wich is mostly composed of dysaerobic

mudstone. The subsequent parasequence is a large cliff-forming unit of anaerobic

mudstone which is capped by a falling stage sandstone unit. The third parasequence is

also mostly composed of dysaerobic mudston and coarsens upward into a thin skeletal

packstone caprock and a thin limey sandstone unit. This HFS thins laterally, measuring

24.3 m in the Thorpe Hills and 15.9 m in the Wasatch Range.

HFS BVL-21

This HFS is dominated by ledge-forming units. It is composed of 3

parasequences, the base of which is dysaerobic mudstone for each. The first is capped by

a skeletal packstone, the second, an onocid-bearing mixed skeletal-coated grain

packstone, and the third is a thick (4.5 m) sandstone unit with reddish oxidization and

exposure features on top. This HFS thins laterally to the east, measuring 9.4 m in the

Thorpe Hills and 5.3 m in the Wasatch Range.

HFS BVL-22

BVL-21 is composed of two parasequences. At its base is a relatively thick

wackestone ledge that comprises the transgressive systems tract of the HFS. It is overlain 31

by dysaerobic mudstone and capped by a thin packstone ledge. A flooding surface

initiates the renewed deposition of dysaerobic mudstone followed by a succession of thin

packstone ledge-forming units. The HFS is capped by two thin sandstone ledges. The

thickness of this HFS measures 10.1 m, 7.9 m, and 9.1 m in the Thorpe Hills, Lake

Mountain, and Wasatch Range, respectively.

HFS BVL-23

This HFS is only partially exposed in the Thorpe Hills and Wasatch Range. The full HFS can be seen on Lake Mountain, containing 10 meters of platy black mudstone, and capped by a packstone ledge package. The unit above this caprock exhibits very distinct lowstand exposure features including brecciation and sheet cracks. On Lake

Mountain, one parasequence comprises BVL-22, and it measures 12.0 m thick. The top of this HFS is estimated to be 10 to 20 meters above the top of the section in the Thorpe

Hills.

HFS BVL-24

HFS BVL-23 is only exposed in the Lake Mountain section. It is only 3.3 meters

thick. The lower half of the HFS is fissile gray mudstone, overlain by a 1.3 m packstone

ledge with exposure features including brecciation, rhizoliths, and sheet cracks.

HFS BVL-25

This sequence marks the transition into siliciclastic-dominated lithologies of the

Butterfield Peaks Formation. Absent in the Thorpe Hills, it is only represented by a

sandy packstone ledge in the top of the Lake Mountain Section. This sequence continues 32

into the Butterfield Peaks formation in the Wasatch Range, and marks the upper limit of

this study.

FACIES MODEL

The widely accepted carbonate ramp model illustrates various depositional microfacies ranging from anaerobic basin to tidal flat and exposure (Fig. 13).

Depositional variables include water depth, light levels, oxygen levels, and energy levels constrained by storm wave base, normal wave base, and sea level. The model indicates that as glacio-eustatic sea-level rises and falls, microfacies on the ramp will prograde and retrograde within their individual intervals of water depth. Though this model is effective at describing many ancient depositional patterns, in the case of the Bridal Veil

Limestone, it appears to have limited applicability.

Detailed stratigraphic descriptions of the Bridal Veil Falls Limestone from

Cascade Mountain, Lake Mountain, and the Thorpe Hills (a total distance of approximately 30 mi (50 km)), indicate that depositionally equivalent beds may be observed at generally consistent stratigraphic levels. These key beds serve as important correlation points between the three sections; indicating that these units were deposited uniformly across the Bridal Veil sub-basin of the greater Oquirrh basin. Additional evidence to this uniformity lies in the carbonate grainstones found in the Bashkirian Ely

Limestone in Nevada, representing the mid-ramp shoal of the carbonate ramp. Eastward and landward of those grainstones, the Bridal Veil sub-basin may represent an enlarged lagoon of that same carbonate ramp. However, due to its size and distribution of microfacies within the sub-basin, this study will attempt to create a workable model for 33 an isolated basin that does not reveal evidence of progradation or retrogradation with the carbonate ramp to the west.

In contrast to the traditional carbonate ramp model, microfacies corresponding to different depositional conditions are deposited uniformly across the Bridal Veil sub-basin

(Fig. 14). Assuming a constant rate of subsidence, parasequences reflect the character in which the carbonate system fills accommodation space resulting from glacio-eustatic sea- level fall. Figure 14 shows the effects of sea-level change on parameters affecting the sediment-water interface (horizontal black line above) through one high-order (HFS) sea- level curve. Through time, glacioeustatic sea level rise and fall imposes different variables related to water depth upon the sea floor. As depositional parameters change, the various microfacies seen in the Bridal Veil Limestone are created. Changing oxygen levels, energy levels, and light levels result in different sedimentary structures, textures, and grain associations at any particular geographic location. For example, during late- highstand (I) sea level was relatively high and low-energy, anaerobic conditions prevailed on the seafloor resulting in deposition of black, laminated mudstone with transported sponge spicules and microbioclasts. As sea level falls (II), low-energy (below storm wave base), but fully oxygenated conditions result in deposition of burrowed mudstone to wackestone. The predominance of in situ brachiopods, bryozoans, and echinoderms

(heterozoan fauna) indicate subphotic conditions. Continued sea level fall (III) sets up peritidal conditions. Bi-modal flow results in ripple cross-laminations, herringbone ripples, and planar laminae. Photozoan grains increase in abundance with peloids being most common. Though no cycle in the Bridal Veil Limestone contains every possible facies, vertical stacking patterns record an overall coarsening-upward succession. The 34

transgressive systems tract in particular is seldom preserved in the Thorpe Hills, but may

be present in thin units at the base of some sequences (BVL 2, BVL-7, BVL-13, etc., see

figure 12). Though not indicated on this figure, Kerans and Tinker (1997) show typical

depth range for normal wave base and storm wave base are 20-40 ft and 100-250 ft, respectively.

According to Walther’s Law, facies that occur in a conformable vertical succession of strata also occurred in laterally adjacent environments (Boggs, 1995).

Ideally, this results in a predictable stack of vertical facies that records the onset and passing of each laterally adjacent facies. Cycles that faithfully record the complete range of facies in a progradational, shallowing upward stack were described as facies complete by Soreghan and Dickinson (1994). However, these authors also describe conditions that would result in deposition of facies-incomplete cycles. For example, when falling sea level abruptly reduces accommodation of lagging carbonate deposition, high-energy conditions are imposed on the formerly mud-prone sea floor. The limited accommodation is then filled with grain-rich, high-energy deposits (grain-rich caprock facies). An RSME marks the contact between the mud-dominated facies and the grain-rich facies, where an unknown amount of carbonate mud has been scoured out, resulting in a facies-incomplete cycle. Cycles of this type are common throughout the Bridal Veil Limestone. Such facies-incomplete cycles seem to predominate on the carbonate-dominated shelf of the

Bridal Veil sub-basin. Vertical facies stacking patterns appear to be the result of sea- level driven changes in depositional conditions rather than waltherian progradation of adjacent lateral facies. 35

Since Pennsylvanian time, western North America experienced episodes of both

shortening in the Sevier orogeny and extension resulting from Basin-Range tectonics.

Thus, the 30 miles of Bashkirian carbonate platform in this study is the current result of

initial compression and subsequent relaxation. Sevier orogenic shortening is estimated at

60% (Yonkee, 1992). Stewart (1980) submitted extension of about 20% to 30% for

Nevada and Utah based on tilting of ranges in the Great Basin region. Differing results

were found by McQuarrie and Wernicke (2005). They synthesized amount, timing, and direction of displacement along three transects through the Basin and Range province concluding 50% extension for the northern portion. Using the initial shortening of 60% and minimum and maximum extension of 20% and 50% respectively, the original distance between Cascade Mountain and the Thorpe Hills exposure was between 50 mi

(80 km) and 63 mi (101 km). Insights from this study may aid in the ongoing attempt to understand the dynamics of nearly uniform deposition across vast carbonate platforms.

LACK OF PHOTOZOAN COMPONENTS

A surprising lack of photozoan carbonates in the Bridal Veil Limestone prompts a

discussion on depositional conditions in the Bashkirian for this area of the Oquirrh basin.

Occurrences of foraminfera, skeletal algae, and ooids are rare throughout the section.

The paucity of photozoan components is unexpected among the sections’ frequent grain-

rich cycle caps and exposure surfaces. Though heterozoan assemblages are often

attributed to cool-water conditions, paleogeography for the Bashkirian show the Oquirrh

basin existed a few degrees north of the equator (Fig. 2, Blakey et al., 2009). Further

complications arise from the carbonates of coeval Ely Limestone in western Utah, 36 containing diverse photozoan skeletal and non-skeletal grains, (Morrow and Webster,

1991).

Shoore and Ritter (2007) narrow the list of possible causes for the near-absence of photozoan carbonates to two plausible theories. First, as observed in processing conodont samples, even some of the coarsest-grained (most thoroughly washed) units found in the Bridal Veil Limestone contain abundant silt and clay. Fine siliciclastic material in the water column could have greatly diminished the depth of light penetration, severely reducing the development of photozoan grains. Secondly, an excess of nutrients related to marine upwelling of cool water could explain the development of a heterozoan association. If the west-facing side of the Oquirrh basin was open, deep, cool, nutrient- rich waters may been able to enter the Bridal Veil sub-basin, limiting a photozoan assemblage. However, carbonate grainstones being deposited to the west in the Ely basin possibly representing the midramp shoal of a greater, gently sloping carbonate ramp, may have created a barrier to such upwelling. Upon further consideration of these two agents, it appears that water turbidity from a constant rain of fine siliciclastics is the primary reason for the dominance of heterozoan assemblages found in the Bridal Veil Limestone.

CONCLUSIONS

• The Bridal Veil Limestone represents 6.4 million years of predominately

carbonate deposition resulting in approximately 430 m of Bashkirian strata.

• Key beds present in the Thorpe Hills, Lake Mountains, and Wasatch Range

indicate generally uniform deposition across the Bridal Veil sub-basin (spanning a

distance of approximately 50 to 60 miles) for much of Bashkirian time. 37

• A limited spectrum of chiefly heterozoan carbonates comprise the bulk of the

section most likely due to siliciclastic-induced turbidity of the water column.

• Facies and facies-stacking patterns are the result of glacio-eustatic sea-level

fluctuation.

• Twenty-five HFS’s consisting of asymmetrical, meter- to decimeter-scale,

coarsening upward carbonate cycles bounded by exposure surfaces comprise the

Bridal Veil Limestone at the Thorpe Hills, Lake Mountain, and the Wasatch

Range.

• The Bridal Veil Limestone is composed of a maximum of 80 parasequences

bounded by flooding surfaces and exposure surfaces as exposed in the Thorpe

Hills, Lake Mountain, and Wasatch Range

• The Bridal Veil Limestone comprises the Lower Absaroka I supersequence,

beginning at the lower Bashkirian unconformity.

REFERENCES

Alexander, D. W., 1978, Petrology and petrography of the bridal Veil Limestone Member of the Oquirrh Formation at Cascade Mountain, Utah: BYU Geology Studies. Masters Thesis: Department of Geology, Brigham Young University, Provo, Utah. Baker, A.A., and Crittenden, M.D., 1961, Geology of the Timpanogos Cave quadrangle, Utah: U.S. Geological Survey Geologic Quadrangle Map GQ-132, 1 plate, scale 1:24,000. Boggs, S., 1995, Principles of Sedimentology and Stratigraphy: Prentice-Hall, New Jersey, p. 774. Biek, R. F., 2004, Geologic Map of the Cedar Fort 7.5-minute quadrangle, Utah County, Utah Geological Survey, M-202, Scale 1:24,000.

Biek, R.F., Clark, D.L., and Christiansen E.H., 2009, Geologic map of the Soldiers Pass quadrangle, Utah County, Utah, Utah Geological Survey, M-235, Scale: 1:24,000.

Bissell, H. J., 1962, Pennsylvanian-Permian Oquirrh basin of Utah: Brigham Young University Geology Studies, v. 9, pt 1, p. 26-49.

Blakey, R.C, and Ranney, W., 2008, Ancient Landscapes, Grand Canyon Association, 1st Edition, xxx p.

Chamberlain, C.K. and Clark, D.L., 1973, Trace fossils and conodonts as evidence for deep-water deposits in the Oquirrh Basin of central Utah. Journal of Paleontology, 47, p. 663-682.

Davis, L. E., Webster, G.D., and Dyman, T.S., 1994, Correlation of the west canyon stratigraphic sections of west canyon limestone and equivalent strata (upper mississppian-middle Pennsylvanian), lower oquirrh group, northern Utah and southeastern Idaho, U.S. Geological Survey, Reston, VA, United States (USA).

Davis, N., 2011, Sequence stratigraphy of the lower Pennsylvanian (Bashkirian, Morrowan) Round Valley Limestone at Split Mountain (Dinosaur National Monument) and in the Eastern Uinta Mountains, Utah, Department of Geology, Brigham Young Universtiy, p. 1-145.

Driese, S.G. and Dott, R.H. Jr., 1984, Model for sandstone-carbonate “cyclothems” based on upper member of Morgan Formation (Middle Pennsylvanian) of Northern Utah and Colorado, American Association of Petroleum Geologists Bulletin, 68, p. 574- 597.

Dunham, R.J., 1962, Classification of carbonate rocks according to depositional texture, in Ham, W.E. (ed.), Classification of carbonate rocks: a symposium: American Association of Petroleum Geologists Memoir 1, p. 108-21. 39

Fischer, A.G., and Sarnthein, M., 1988, Airborne silts and dune-derived sands in the Permian of the Delaware basin: Journal of Sedimentary Petrology, v. 58, p. 637-643.

Flügel, Erik, 2004, Microfacies of Carbonate Rocks: Analysis, Interpretation and Application, Springer, New York, p. 1.

Fransom, O.M., 1950, Sedimentation of the basal Oquirrh Formation Provo Canyon, Utah: Provo, Brigham Young University, M.S. thesis, 55 p.

Goldhammer, R.K., Oswald, E.J., and Dunn, P.A., 1991, Hierarchy of stratigraphic forcing: Example from Middle Pennsylvanian shelf carbonates of the Paradox basin, in Franseen, E.K., Watney, W.L., St. Kendall, C.G.C., and Ross, W., editors, Sedimentary modeling, Kansas Geological Survey Bulletin 233, p. 361-413.

Golonka, J. and Kiesslin, W., 2002, Phanerozoic time scale and definition of time slices, in Phanerozoic Reef Patterns, SEPM Special Publication, No. 72, p. 11-20.

Grammer, G.M., Eberli, G.P. Van Buchem, F.S.P, Stevenson, G.M., and Homewood, P.W., 2000, Application of High Resolution Sequence Stratigraphy in Developing an Exploration and Production Strategy for a Mixed Carbonate/Siliciclastic System (Carboniferous) Paradox Basin, Utah, USA, in Homewood, P.W. and Eberli G.P., (eds.), Genetic Stratigraphy on the Exploration and the Production Scales: Case studies from the Pennsylvanian of the Paradox Basin and the Upper Devonian of Alberta, Memoire 24, p. 29-69.

Hintze, L. F. and Kowallis, B.J., 2009, A Field Guide to Utah’s Rocks: Geologic History of Utah, Brigham Young University Special Publication 9, p. 1-225. James, N.P., 1997, The cool-water carbonate depositional realm, in James, N.P., and Clarke, J.A.D., editors, Cool-water carbonates: Society for Sedimentary Geology (SEPM) Special Publication 56, p. 1-20.

Jordan, T.E., 1979, Lithofacies of the Upper Pennsylvanian and Lower Permian Oquirrh Basin, northwest Utah: Utah Geology, v. 6, no. 2, p. 41-56.

Jordan, T.E., 1981, Enigmatic deep-water depositional mechanisms, upper part of the Oquirrh Group, Utah, Journal of Sedimentary Petrology, vol. 51, no. 3, p. 879-894.

Jordan, T.E., and Douglass, R.C., 1980, Paleogeography and structural development of the Late Pennsylvanian to Early Permian Oquirrh Basin, northwestern Utah, in Fouch, T.D., and Magathan, E.R., eds., Paleozoic Paleogeography of the West-Central United States: West-Central United States Paleogeography Sympsium 1: Rocky Mountain Section Society of Economic Paleontologists Mineralogists, Denver, Colorado, p. 217-238.

Kerans, C., and Tinker, S.W., 1997, Sequence stratigraphy and characterization of carbonate reservoirs, Society for Sedimentary Geology Short Course Notes No. 40, p. 1-130. Konopka, E.H., and Dott, R.H., Jr., 1982, Stratigraphy and sedimentology, lower part of the Butterfield Peaks Formation (Middle Pennsylvanian), Oquirrh Group, at Mt. Timpanogos, Utah, in Neilson, D.L., editor, Overthrust belt of Utah: Utah Geological Association Publication 10, p. 215-234. Lucia, F.J., 1995, Rock-Fabric/Petrophysical Classification of Carbonate Pore Space for Reservoir Characterization, AAPG Bulletin, V. 79, No. 9, p. 1275-1300. Mazzullo, S. J., and Hedrick, C.L., 1985, Lithofacies, stratigraphy and depositional models of the back-reef Guadalupian section (Queen, Seven Rivers, Yates, and Tansill Formations)—day 1 road log and locality guide; in, Permian Carbonate/Clastic Sedimentology, Guadalupe Mountains, Cunningham, B.K., and Hedrick, C.L., eds.: Permian Basin Section, Society of Economic Paleontologists and Mineralogists, Publication 85-24, p. 3-19. McQuarrie, Nadine and Wernicke, Brian P., 2005, An animated tectonic reconstruction of southwestern North America since 36 Ma, Geosphere, v. 1, p. 147-172. Morrow, J. R., and Webster, G.D., 1991, Carbonate microfacies and related conodont biofacies, Mississippian-Pennsylvanian boundary strata, Granite Mountain, west- central Utah: Brigham Young University Geology Studies, v. 37, p. 99-124. Nygreen, P. W., 1958, The Oquirrh Formation; stratigraphy of the lower portion in the type area and near Logan, Utah. Utah Geological and Mineralogical Survey Bulletin, 67. Plint, A.G., 2010, Wave- and Storm-Dominated Shoreline and Shallow-Marine Systems, in James, N.P., and Dalrymple, R.W., Facies Models 4, Geological Association of Canada, p. 167-199.

Saller, A.H., Dickson, J.A.D., and Matsuda, F., 1999, Evolution and distribution of porosity associated with subaerial exposure in upper Paleozoic platform limestones, West Texas, American Association of Petroleum Geologists Bulletin, 83, p. 1835- 1854.

Shoore, D.J., 2004, Sequence Stratigraphy of the Bridal Veil Falls Limestone (Carboniferous), Oquirrh Group, on Cascade Mountain, Utah: A Standard Morrowan Cyclostratigraphy for the Oquirrh Basin, Department of Geology, Brigham Young University, p. 1-189.

Shoore, D.J, Ritter, S.M., 2007, Sequence Stratigraphy of the Bridal Veil Limestone Member of the Oquirrh Formation (Lower Pennslvanian) in the Central Wasatch Range, Utah – Towards a Bashkirian Cyclostratigraphy for the Oquirrh Basin. 41

Soreghan, G.S. and Dickinson, W.R., 1994, Generic types of stratigraphic cycles contolled by eustacy, Geology, 22, p. 759-761. Spurr, J. E., 1895, Economic geology of the Mercur mining district, Utah: U.S. Geol. Survey 16th Ann. Rept., pt. 2, p. 374-376.

Stewart, J. H., 1980, Regional tilt patterns of late Cenozoic basin-range fault blocks, western United States, Geological Society of America Bulletin, 91(8) p. 460-464.

Tooker E. W., and Roberts, R. J., 1970, Upper Paleozoic Rocks in the Oquirrh Mountains and Bingham Mining District, Utah, Geological Survey Professional Paper 629-A, pp. A1-A76.

Welsh, J.E., and James, A.H., 1961, Pennsylvanian and Permian stratigraphy of the central Oquirrh Mountains, Utah, in Cook, D.R., ed., Geology of the Bingham mining district and northern Oquirrh Mountains: Utah Geolocial Society Guidebook 16, p. 1- 16.

Yonkee, W. A., 1992, Basement-cover relations, Sevier orogenic belt, northern Utah, Geological Society of America Bulletin, v. 104 no. 3 p. 280-302.

FIGURES

Figure 1 Stratigraphic time chart of Pennsylvanian System showing Bashkirian- Morrowan equivalence, (modified from stratigraphy.org and Hintze, 2009).

Figure 2 Paleogeography of western North America for the early Pennsylvanian (Bashkirian) 318.1-311.7 Ma. The position of the equator at that time indicates trade winds were from north to south. Eolian sands from the Wyoming shelf introduced angular quartz silt into the Bridal Veil Intracratonic basin consistently throughout this time period (modified from Blakey and Ranney, 2008 and Driese, 1984).

Figure 3 Index map showing geographical relationships of the Thorpe Hills, Lake Mountain, West Canyon, Oquirrh Range, and Cascade Mountain in Utah, USA, (modified from maps.google.com topographic maps).

Figure 4 Modified Dunham (1962) classification by Lucia (1995). This classification scheme is based upon rock fabric to make ‘classification more compatible with petrophysical considerations’ (Lucia, 1995). Packstones have been sub-divided into two rock-fabric classes, mud-dominated and grain dominated packstones (modified from Davis, 2011).

Figure 5 Thorpe Hills Section microfacies hierarchy separates all units into non- caprock, caprock, and sandstone. Non-caprocks are further separated by oxygen levels: anaerobic, dysaerobic, and aerobic. Oxygen levels are further separated based on rock texture. Cap rocks are separated by skeletal grains, mixed, and non-skeletal grains, and these groups are again divided based on rock texture. Numbered 1-11, this stacking pattern represents an idealized complete shallowing-upward parasequence. 46

Figure 6 Stratigraphic section measured at the Thorpe Hills with upper Manning Canyon Shale sandstones at the base and lowermost Butterfield Peaks sandstones at the top. Shows 23 of 25 high-frequency sequences for the Bridal Veil Limetone, as well as 60 parasequences, and microfacies stacking pattrerns.

Figure 7 A) Photomicrograph of laminated mudstone representing MF 1. B) Photomicrograph of disrupted-laminite, spiculite mudstone representing MF 2. C) Photomicrograph of disrupted-laminite spiculite and sparse skeletal wackestone representing MF 3. D) Field photograph of disrupted laminae and some burrows representing MF 2. E) Photomicrograph of fully-bioturbated mudstone representing MF 4. F) Field photograph of bioturbated mudstone with burrows representing MF 4. 54

Figure 8 A) Photomicrograph of skeletal wackestone representing MF 5. B) Photomicrograph of whole-fossil skeletal packstone representing MF 6. C) Field photograph of whole-fossil skeletal packstone representing MF 6. D) Photomicrograph of skeletal wackestone representing MF 7. E) Photomicrograph of skeletal packstone representing MF 8. F) Field photograph showing sharp transition from skeletal wackestone of MF 7 (lower) into skeletal packstone of MF 8 (upper).

Figure 9 A) Photomicrograph of a mixed skeletal-coated grain grainstone representing MF 9. B) Photomicrograph of oncoid-bearing, mixed skeletal-coated grain packstone representing MF 9. C) Photomicrograph of peloidal packstone with calcite-filled fenestrae representing MF 10. D) Photomicrograph of quartzose, peloidal, skeletal grainstone representing MF 10. E) Field photograph of cross-ripple laminated ledge representing MF 10. F) Field photograph showing ripple-laminated, tidalite ledge representing MF 10.

Figure 10 A) Photomicrograph of quartzose sandstone MF 11. B) Field photograph of sandstone ledge representing MF 11. C) Field photograph of planar tabular crossbedding in sandstones of the Bridal Veil Limestone. D) Field photograph of rhizolith indicating exposure. E) Field photograph of multiple rhizoliths on an exposure surface. F) Field photograph showing sheet cracks in upper 15 cm of ledge-forming unit representing exposure. 57

Figure 11 Field photograph of a Regressive Surface of Marine Erosion (RSME). RSME’s occur where a sharp, laterally extensive contact marks the abrupt transition from a mud-prone facies (microfacies 1 through 5) below the surface to grain-rich facies (microfacies 8 through 11) above. Grain-filled burrows often extend downward into the muddier facies.

Figure 12 Stratigraphic section measured at the Thorpe Hills, Lake Mountain, and the Wasatch Range (Cascade Mountain) with upper Manning Canyon Shale sandstones at the base and lowermost Butterfield Peaks sandstones at the top. Shows 25 high-frequency sequences and corresponding parasequences. Microfacies stacking pattrerns also shown for the Thorpe Hills section.

Figure 13 Microfacies of the widely accepted carbonate ramp model not used in this study, (Shoore and Ritter, 2007).

Figure 14 Diagram showing effects of sea-level change on parameters affecting the sediment-water interface (horizontal black line above) through one high-order (HFS) sea-level curve. Through time, glacioeustatic sea level rise and fall imposes different variables related to water depth upon the sea floor. As depositional parameters change, the various microfacies seen in the Bridal Veil Limestone are created. Changing oxygen levels, energy levels, and light levels result in different sedimentary structures, textures, and grain associations at any particular geographic location. For example, during late-highstand (I) sea level was relatively high and low-energy, anaerobic conditions prevailed on the seafloor resulting in deposition of black, laminated mudstone with transported sponge spicules and microbioclasts. As sea level falls (II), low-energy (below storm wave base), but fully oxygenated conditions result in deposition of burrowed mudstone to wackestone. The predominance of in situ brachiopods, bryozoans, and echinoderms (heterozoan fauna) indicate subphotic conditions. Continued sea level fall (III) sets up peritidal conditions. Bi-modal flow results in ripple cross- laminations, herringbone ripples, and planar laminae. Photozoan grains increase in abundance with peloids being most common. Though no cycle in the Bridal Veil Limestone contains every possible facies, vertical stacking patterns record an 61

overall coarsening-upward succession. The transgressive systems tract in particular is seldom preserved in the Thorpe Hills, but may be present in thin units at the base of some sequences (BVL 2, BVL-7, BVL-13, etc., see figure 12). Though not indicated on this figure, Kerans and Tinker (1997) show typical depth range for normal wave base and storm wave base are 20-40 ft and 100-250 ft, respectively.

APPENDIX A

Thin Section Descriptions and Point Counts

# Locality PC TEX BED I MF MIC OOD QTZ PEL ONC INT CRI ECH BIV GAS BRA BRY CON OST SPS FOR TRI ALG ASP BIO PCT POR PT 5 TWCW 3 WS LAM 1 1 76.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.3 0.0 0.0 0.0 0.0 0.0 23.3 0.0 0.0 0.0 0.0 0.0 99.9 0.0 7 TWCW 3 MS LAM 2 2 89.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 8 TWCW 3 MS LAM 1 2 88.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 8 TWCW 3 MS LAM 1 2 79.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 21.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 8 TWCW 3 WS MSS 2 2 81.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 19.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 9 TWCW 3 MS MSS 2 2 91.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 9 TWCW 3 WS MSS 2 2 51.7 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 47.3 0.0 0.0 0.0 0.0 0.0 100.0 0.0 11 TWCW 3 MS LAM 2 2 91.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 100.0 0.0 12 TWCW 3 MS LAM 2 2 88.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11.7 0.0 0.0 0.0 0.0 0.0 99.7 0.0 13 TWCW 3 WS MSS 3 3 51.7 0.0 7.3 0.0 0.0 0.0 1.0 1.7 0.0 0.0 5.7 0.0 0.0 0.3 32.3 0.0 0.0 0.0 0.0 0.0 100.0 0.0 13 TWCW 3 WS MSS 3 3 69.3 0.0 13.7 6.0 0.0 0.0 3.0 0.0 0.0 0.0 3.3 0.0 0.0 0.0 4.3 0.0 0.0 0.0 0.0 0.3 99.9 0.0 14 TWCW N LAM 2 0.0 0.0 15 TWCW 3 MS LAM 2 3 75.0 0.0 14.0 2.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 16 TWCW N LAM 1 1 0.0 0.0 17 TWCW 3 MS LAM 2 2 85.0 0.0 11.7 0.3 0.0 0.0 0.3 0.3 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.3 99.9 0.0 19 TWCW 3 MS LAM 2 2 71.0 0.0 19.3 8.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 20 TWCW 3 MS MSS 2 2 70.7 0.0 15.0 3.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 11.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 21 TWCW 3 SG CSB 2 10 74.3 0.0 17.3 5.3 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.3 0.0 0.0 0.0 0.3 99.8 0.0 22 TWCW 3 SS CSB 2 10 49.3 0.0 41.3 1.3 0.0 0.0 3.3 00000004.7 0000099.9 0.0 23 TWCW 3 GS MSS 3 10 18.7 0.0 32.3 9.7 0.0 0.0 15.0 1.0 0.3 0.0 3.0 0.0 0.0 0.3 1.0 0.0 0.0 0.0 0.0 0.0 100.0 18.7 EA 24 TWCW 3 WS MSS 2 10 68.0 0.0 25.7 0.3 0.0 0.0 4.7 0.3 0.0 0.0 0.3 0.0 0.0 0.3 0.3 0.0 0.0 0.0 0.0 0.0 99.9 0.0 25 TWCW 3 MS LAM 2 10 62.3 0.0 34.3 1.3 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 0.0 26 TWCW 3 MS MSS 2 10 85.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 14.3 F 27 TWCW 3 MS MSS 3 4 99.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 100.0 0.0 29 TWCW 3 MS MSS 3 2 97.0 0.0 0.0 0.3 0.0 0.0 2.3 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 0.0 31 TWCW 3 MDP LAM 2 10 76.3 0.0 4.7 4.3 0.0 0.0 14.3 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 0.0 33 TWCW 3 GS MSS 3 9 1.3 0.0 7.0 10.0 0.0 8.7 37.7 1.3 1.0 0.0 14.7 1.3 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 100.0 16.7 ESGA 36 TWCW N MDP MSS 3 7 37 TWCW 3 MDP MSS 3 5 43.3 0.0 0.0 2.0 0.0 5.3 16.0 0.0 0.0 0.0 30.3 3.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 0.0 38 TWCW 3 MDP MSS 3 5 53.3 0.0 0.0 0.0 0.0 4.0 5.7 0.0 1.0 0.0 10.3 23.7 0.0 0.3 0.7 0.0 0.7 0.0 0.0 0.3 100.0 0.0 39 TWCW 3 MDP MSS 3 5 56.0 0.0 0.7 0.0 0.0 0.0 3.7 0.0 1.3 0.3 13.3 22.0 0.0 1.3 0.3 0.0 0.7 0.0 0.0 0.0 99.9 0.3 S 40 TWCW 3 WS MSS 3 7 62.7 0.0 7.3 3.3 0.0 0.3 9.7 0.0 1.0 0.0 9.3 0.3 0.0 0.0 5.7 0.0 0.0 0.0 0.0 0.0 99.9 0.3 S 41 TWCW 3 MS LAM 2 2 85.0 0.0 7.7 0.0 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 6.3 0.0 0.0 0.0 0.0 0.3 100.0 0.0 42 TWCW 3 MS LAM 1 10 88.3 0.0 1.0 3.7 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 6.3 F 43 TWCW 3 MS LAM 2 10 77.7 0.0 0.7 19.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 2.3 F 44 TWCW 3 GS MSS 3 10 44.3 6.0 18.3 16.3 0.0 0.0 5.0 2.7 1.0 0.0 5.7 0.0 0.0 0.0 0.0 0.3 0.3 0.0 0.0 0.0 99.9 0.0 46 TWCW 3 MDP MSS 3 6 42.7 0.0 1.0 0.0 0.0 0.0 25.3 0.3 0.0 0.0 30.3 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 0.0 48 TWCW 3 MDP MSS 3 8 55.7 0.0 0.0 0.0 0.0 1.0 7.3 0.0 0.0 0.3 23.3 3.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 8.7 S 48 TWCW 3 GDP MSS 3 8 21.7 0.0 0.3 0.3 0.0 0.0 28.3 3.0 0.3 0.0 28.7 14.7 0.0 0.0 0.0 0.0 0.7 0.0 T 0.0 100.0 2.0 EASG 48 TWCW 3 MDP MSS 3 8 53.0 0.0 2.0 1.7 0.0 0.0 19.3 2.7 3.0 0.0 14.3 3.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 99.9 0.3 S 49 TWCW 3 WS MSS 3 5 86.0 0.0 0.3 0.7 0.0 0.3 6.7 0.3 0.7 0.0 3.0 0.7 0.0 0.0 1.3 0.0 0.0 0.0 0.0 0.0 100.0 0.0 51 TWCW 3 WS MSS 3 6 74.0 0.0 0.0 0.0 0.0 0.0 7.7 0.7 0.3 0.0 13.0 2.0 0.0 0.0 2.0 0.0 0.3 0.0 0.0 0.0 100.0 0.0 52 TWCW 3 GDP MSS 3 8 31.0 0.0 0.3 1.7 0.0 0.0 28.3 1.7 4.3 0.3 15.0 4.3 0.0 0.3 0.0 0.0 0.7 0.0 0.0 0.0 99.9 12.0 ES 55 TWCW 3 WS MSS 2 1 76.0 0.0 0.7 0.0 0.0 0.0 0.3 6.3 1.3 0.0 9.7 0.0 0.0 0.3 5.3 0.0 0.0 0.0 0.0 0.0 104.9 5.0 S 56 TWCW 3 MDP MSS 3 7 64.3 0.0 0.0 0.0 0.0 0.0 8.0 0.7 0.0 0.3 22.0 0.0 0.0 0.0 1.3 0.0 0.0 0.0 0.0 0.0 99.9 3.3 S 57 TWCW 3 MS LAM 2 1 85.0 0.0 8.7 0.0 0.0 0.0 4.3 0.0 0.0 0.0 1.7 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 100.0 0.0 58 TWCW 3 GS MSS 3 8 10.0 0.0 0.0 0.7 0.0 0.0 30.0 1.3 1.0 0.0 16.0 3.3 0.0 0.3 0.0 0.0 0.3 0.0 0.0 0.0 102.9 40.0 E 58 TWCW 3 MDP MSS 3 64.0 0.0 0.0 1.0 0.0 0.0 17.7 0.0 0.0 0.0 17.0 0.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 100.0 0.0 60 TWCW 3 GDP MSS 3 8 29.7 0.0 1.7 0.0 0.0 0.0 27.0 0.0 0.0 0.0 23.7 10.0 0.0 0.0 0.0 0.0 0.3 0.0 T 0.0 100.1 7.7 62 TWCW 3 GS MSS 3 9 17.7 5.7 0.0 4.7 0.0 2.0 17.7 0.3 0.7 0.7 22.7 10.7 0.0 0.0 0.0 0.0 0.7 0.0 9.0 0.0 106.9 14.3 SE 63 TWCW 3 WS LAM 2 5 90.0 0.0 5.3 0.0 0.0 0.0 0.3 0.0 0.0 0.0 4.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 0.0 64 TWCW 3 WS MSS 3 5 85.7 0.0 3.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 10.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.1 0.0 S 65 TWCW 3 GDP MSS 3 9 54.3 0.3 1.3 3.7 0.0 0.3 10.0 0.7 1.7 0.3 11.7 11.0 0.0 0.0 0.0 0.0 0.3 0.0 0.7 0.0 100.0 3.7 ES 66 TWCW 3 WS MSS 3 3 62.7 0.0 28.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 1.3 3.0 0.0 0.0 1.7 0.0 0.0 0.0 0.0 0.3 100.0 1.0 GS 66 TWCW 3 WS MSS 3 3 69.0 0.0 18.7 0.0 0.0 0.0 2.0 0.0 0.3 0.0 1.0 4.3 0.0 0.0 2.0 0.0 0.0 0.0 0.0 1.7 100.0 1.0 S 68 TWCW 3 GDP MSS 3 9 23.7 0.3 0.3 2.0 0.0 0.0 15.0 0.0 10.0 1.0 16.0 21.3 0.0 0.0 0.0 0.0 0.3 0.0 T 0.0 99.9 10.0 ESG 70 TWCW 3 GDP MSS 3 9 33.3 1.0 0.0 8.3 0.0 2.7 13.3 0.7 5.7 2.7 3.0 0.7 0.0 0.0 0.0 1.0 0.0 1.0 0.3 92.7 19.0 ES 71 TWCW 3 MS LAM 1 1 94.7 0.0 2.7 0.0 0.0 0.0 0.0 0.3 0.3 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 72 TWCW 3 WS MSS 3 7 86.3 0.0 0.0 0.0 0.0 0.0 2.0 4.7 2.0 0.0 4.3 0.0 0.0 0.3 0.0 0.0 0.3 0.0 0.0 0.0 100.9 1.0 S 74 TWCW 3 WS MSS 3 5 82.7 0.0 0.0 0.0 0.0 0.0 1.3 12.3 0.0 0.0 2.3 0.0 0.0 0.0 0.0 0.3 1.0 0.0 0.0 0.0 99.9 0.0 76 TWCW 3 MDP MSS 3 9 65.3 0.0 1.0 11.7 0.0 0.0 2.7 0.0 0.0 0.7 3.0 6.3 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 91.0 0.0 77 TWCW 3 MS LAM 1 1 96.7 0.0 2.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 100.1 0.0 78 TWCW 3 WS MSS 3 7 78.0 0.0 0.3 0.0 0.0 0.0 8.0 1.3 1.0 0.0 4.3 0.7 0.0 0.7 5.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 79 TWCW 3 MS LAM 1 3 94.3 0.0 2.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 80 TWCW 3 MS LAM 2 2 90.0 0.0 3.3 0.0 0.0 0.0 1.3 0.0 0.0 0.0 0.3 0.0 0.0 0.0 4.0 0.0 0.0 0.0 0.0 1.0 99.9 0.0 82 TWCW 3 MDP MSS 3 8 62.3 0.0 0.3 0.3 0.0 0.3 24.3 0.0 2.3 0.0 7.3 1.3 0.3 0.3 0.3 0.0 0.3 T? 0.0 0.0 99.6 0.0 83 TWCW 3 MS LAM 2 3 79.0 0.0 6.3 0.0 0.0 0.0 6.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 99.9 0.0 84 TWCW 3 MS LAM 2 7 89.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.3 0.0 0.0 0.0 0.0 0.0 99.6 0.0 86 TWCW 3 GDP MSS 3 8 50.0 0.0 0.7 0.0 0.0 0.0 18.0 0.0 7.3 2.0 11.0 3.7 0.0 0.0 0.0 0.0 0.0 0.0 T 0.0 100.0 7.3 EASG 79 TW 3 MS LAM 1 99.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 79 TW 3 MS LAM 2 75.3 0.0 23.0 0.0 0.0 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 80 TW 3 MS LAM 2 81.3 0.0 0.3 0.0 0.0 0.0 0.0 0.7 0.0 0.0 0.0 0.3 0.0 0.0 17.3 0.0 0.0 0.0 0.0 0.0 99.9 0.0 81 TW 3 MS LAM 2 96.0 0.0 0.0 2.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 1.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 83 TW 3 MS LAM 2 90.0 0.0 0.0 1.3 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 99.9 0.0 84 TW 3 WS MSS 3 85.7 0.0 0.0 1.7 0.0 0.3 0.3 4.0 1.3 0.0 2.3 0.7 0.0 0.7 3.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 84 TW 3 WS MSS 3 74.3 0.0 0.0 0.3 0.0 0.0 0.7 9.0 1.3 0.0 3.0 1.0 0.0 1.7 8.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 85 TW 3 MDP MSS 3 24.0 0.0 0.0 30.3 0.0 0.3 2.7 16.0 15.0 0.7 5.0 2.4 0.0 0.7 0.3 0.0 0.7 0.0 0.0 2.0 100.1 0.0 86 TW 3 MDP MSS 3 50.0 0.0 0.0 3.7 0.0 1.3 0.0 29.5 2.3 0.0 5.7 6.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 99.8 86 TW 3 MDP MSS 3 50.0 0.0 0.0 3.7 0.0 1.3 0.0 29.5 2.3 0.0 5.7 6.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 99.8 0.0 86 TW N MDP MSS 3 91 TW 3 SS CSB 2 45.3 0.0 34.0 1.0 0.0 2.4 12.0 0.3 0.3 0.0 3.7 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 91 TW 3 PC MSS 1 10 9.7 0.0 8.7 0.0 0.0 78.0 2.3 0.0 0.3 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 92 TW 3 MS LAM 2 10 70.3 0.0 15.7 2.0 0.0 0.0 3.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 8.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 93 TW 3 SS CSB 2 10 55.3 0.0 38.3 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 99.9 5.7 B 95 TW 3 MDP MSS 3 38.7 0.0 0.7 1.3 0.0 1.3 15.7 1.3 5.3 1.0 23.0 2.3 0.0 0.3 0.0 0.0 1.7 0.0 0.3 0.0 99.9 7.0 EASG 97 TW 3 SS CSB 2 65.3 0.0 30.3 0.0 0.0 0.0 0.7 0.0 0.0 0.0 1.3 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 99.9 0.3 B 98 TW 3 MDP MSS 3 58.7 0.0 1.0 0.0 0.0 0.0 15.0 0.0 2.0 0.0 21.3 1.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 100.0 0.7 S 98 TW 3 WS MSS 3 51.3 0.0 0.0 0.3 0.0 0.0 6.7 0.0 0.3 0.3 27.7 9.3 0.0 0.0 0.0 0.0 1.7 0.0 0.0 0.0 99.9 2.3 S 98 TW 3 MS MSS 3 3 95.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 4.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 99 TW 3 WS LAM 2 10 74.7 0.3 1.0 15.3 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.0 0.0 0.0 0.0 0.0 0.0 100.0 5.0 SE 100 TW 3 MDP MSS 3 53.7 0.0 0.0 0.3 0.0 0.0 11.3 0.7 0.0 0.0 24.3 7.0 0.0 0.0 0.0 0.0 2.3 0.0 0.0 0.0 99.9 0.3 S 102 TW 3 WS MSS 3 88.0 0.0 0.7 0.0 0.0 0.0 4.3 0.0 0.3 0.0 6.3 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 99.9 0.0 104 TW N 105 TW 3 WS MSS 3 79.7 0.0 0.0 0.0 0.0 0.0 6.3 0.0 1.3 0.0 10.0 0.0 0.0 0.3 0.7 0.0 0.3 0.0 0.0 0.7 99.3 0.0 105 TW 3 WS MSS 3 78.0 0.0 2.3 0.0 0.0 0.0 7.3 0.0 0.0 0.0 8.0 0.7 0.0 0.0 1.3 0.0 0.7 0.0 0.0 1.7 100.0 0.0 106 TW 3 MDP MSS 3 45.0 0.0 0.0 0.7 0.0 0.0 13.7 0.0 0.0 0.0 37.7 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.3 100.1 1.7 ES 108 TW 3 MS MSS 2 95.7 0.0 1.0 0.0 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.7 0.0 0.0 0.0 0.0 0.0 100.1 108 TW N MDP MSS 3 110 TW N MS LAM 2 111 TW N MDP MSS 3 112 TW N MDP MSS 3 113 TW N MS LAM 2 114 TW 3 MS MSS 2 84.0 0.0 0.0 0.0 0.0 0.0 4.0 1.7 0.3 0.0 0.3 1.0 0.0 0.0 8.7 0.0 0.0 0.0 0.0 0.0 100.0 0.0 115 TW 3 SS CSB 1 19.7 0.0 80.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 116 TW 3 MS MSS 3 90.0 0.0 0.0 0.0 0.0 0.0 3.3 0.0 0.0 0.0 1.7 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 118 TW N WS MSS 3 119 TW N MDP MSS 3 120 TW N WS MSS 3 5 121 TW N SS CSB 1 11 121 TW N SS LAM 2 11 122 TW N MDP MSS 3 6 124 TW N MS LAM 1 1 124 TW N MS MSS 2 135 TW N MDP MSS 3 8 137 TW N WS MSS 3 6 138 TW N WS MSS 3 7 140 TW N GS MSS 3 6 141 TW N SMP MSS 3 9 143 TW N SMP MSS 3 5 144 TW N SLS LAM 1 10 145 TW N WS MSS 3 4 147 TW N MDP MSS 3 8 149 TW N SMP MSS 3 8 151 TW 3 MS LAM 2 3 86.3 0.0 1.7 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 11.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 154 TW N SS CSB 1 11 156 TW N WS LAM 2 156 TW N WS LAM 2 156 TW N WS MSS 3 158 TW N MDP MSS 3 8 160 TW N WS MSS 3 4 160 TW N WS MSS 3 161 TW N SS MSS 2 10 161 TW N SW LAM 2 10 163 TW N SM LAM 1 163 TW N 164 TW N SS LAM 1 11 166 TW 3 MDP MSS 3 9 54.7 0.0 1.0 1.3 10.3 0.0 13.7 0.0 2.0 0.0 10.0 5.7 0.0 0.3 0.0 0.0 1.0 0.0 0.0 0.0 100.0 0.0 168 TW N SW MSS 3 7 62.0 0.0 13.3 0.3 0.0 0.0 5.0 0.7 3.3 0.0 13.3 1.3 0.0 0.3 0.0 0.3 0.0 0.0 0.0 0.0 99.8 0.0 S 5 TH-E N 8 6 TH-E N 11 9 TH-E N 9 10 TH-E N 2 11 TH-E N 7 12 TH-E N 1 16 TH-E N 9 19 TH-E N 9 11 TH-CS N MDP MSS 8 12 TH-CS N 4

Legend # Sample Number PC Point Count TEX Texture BED Bedding I Ichnology Index MF Microfacies MIC Micrite OOD Ooid QTZ Quartz Silt PEL Peloid ONC Oncoid INT Intraclast CRI Crinoid ECH Echinoid BIV Bivalve GAS Gastropod BRA Brachiopod BRY Bryozoan CON Conodont OST Ostracode SPS Sponge Spicule FOR Foraminifer TRI Trilobite ALG Alga ASP Asphaltina BIO Microbioclast PCT Point Count Total POR Porosity PT Porosity Type TextureMS - Mudstone WS - Wackestone MDP - Mud-dominated Packstone GDP - Grain-dominated Packstone GS - Grainstone SLS - Siltstone SS - Sandstone PC - Pebble Conglomerate SM - Sandy Mudstone SW - Sandy Wackestone SMP - Sandy Mud-dominated Packstone SG - Sandy Grainstone BeddingLAM - Laminated MSS - Massive CSB - Crossbedded PT A - Intrapartical E - Interpartical S - Shelter G - Growth Framework B - Burrow F - Fenestral PC N - None 3 - 300 pts 68

APPENDIX B

Thorpe Hills Section Unit and Microfacies Thickness

TH Thin Unit Alt Unit MF Thickness TS Section 1 BTW 1 0.8 N 2 BTW 2 1 0.6 N 3 BTW 3 11 1.2 N 4 BTW 4 11 3.2 N 5 BTW 5 1 N 6 BTW 6 1 0.3 N 7 BTW 7 11 0.8 N 8 BTW 8 1.6 N 9 BTW 9 1 10.5 N 10 BTW 10 0.2 N 11 BTW 11 1 1 N 12 BTW 12 0.2 N 13 BTW 13 1 6.9 N 14 BTW 14 11 1 N 15 BTW 15 11 0.6 N 16 BTW 16 1 7 N 17 TWCW 5 1 0.6 Y TWCW 5 18 TWCW 6 1 0.6 N 19 TWCW 7 2 3.5 Y 20 TWCW 8 2 3 Y TWCW 8 21 TWCW 9 2 1 Y 22 TWCW 10 2 2 N 23 TWCW 11 2 3.5 Y TWCW 11 24 TWCW 12 2 3 Y TWCW 12 25 TWCW 13 3 0.3 Y TWCW 13 26 TWCW 14 2 0.3 Y TWCW 14 27 TWCW 15 3 0.25 Y TWCW 15 28 TWCW 16 1 0.05 Y TWCW 16 29 TWCW 17 2 0.05 Y TWCW 17 30 TWCW 18 2 0.05 Y TWCW 18 31 TWCW 19 2 0.1 Y TWCW 19 32 TWCW 20 2 0.1 Y TWCW 20 33 TWCW 21 10 0.2 Y TWCW 21 34 TWCW 22 10 0.6 Y TWCW 22 35 TWCW 23 10 0.5 Y TWCW 23 36 TWCW 24 10 0.3 Y TWCW 24 37 TWCW 25 10 1 Y TWCW 25 38 TWCW 26 10 0.25 Y TWCW 26 39 TWCW 27 4 0.2 Y TWCW 27 40 TWCW 28 0.2 N 41 TWCW 29 2 0.2 Y TWCW 29 42 TWCW 30 2 3.8 N 43 TWCW 31 10 0.8 Y TWCW 31 44 TWCW 32 1 1.3 N 45 TWCW 33 9 0.25 Y TWCW 33 46 TWCW 34 1 6.8 N 70

47 TWCW 35 1 12.8 N 48 TWCW 36 9 0.55 Y TWCW 36 49 TWCW 37 5 0.1 Y TWCW 37 50 TWCW 38 5 1.5 Y TWCW 38 51 TWCW 39 5 0.2 Y TWCW 39 52 TWCW 40 7 0.3 Y TWCW 40 53 TWCW 41 2 3.2 Y TWCW 41 54 TWCW 42 10 2 Y TWCW 42 55 TWCW 43 10 1.5 Y TWCW 43 56 TWCW 44 10 1 Y TWCW 44 57 TWCW 45 1 2.5 N 58 TWCW 46 6 0.1 Y TWCW 46 59 TWCW 47 1 0.1 N 60 TWCW 48 8 3 Y TWCW 48 61 TWCW 49 5 0.1 Y TWCW 49 62 TWCW 50 1 20.5 N 63 TWCW 51 6 0.05 Y TWCW 51 64 TWCW 52 8 1 Y TWCW 52 65 TWCW 53 1 0.8 N 66 TWCW 54 0.2 N 67 TWCW 55 1 1 Y TWCW 55 68 TWCW 56 7 0.2 Y TWCW 56 69 TWCW 57 2 0.8 Y TWCW 57 70 TWCW 58 8 0.7 Y TWCW 58 71 TWCW 59 1 3.4 N 72 TWCW 60 8 0.5 Y TWCW 60 73 TWCW 61 1 0.8 N 74 TWCW 62 9 0.9 Y TWCW 62 75 TWCW 63 5 2.5 Y TWCW 63 76 TWCW 64 5 0.2 Y TWCW 64 77 TWCW 65 9 0.9 Y TWCW 65 78 TWCW 66 3 3.8 Y TWCW 66 79 TWCW 67 0.3 N 80 TWCW 68 9 1.8 Y TWCW 68 81 TWCW 69 1 5.2 N 82 TWCW 70 9 0.5 Y TWCW 70 83 TWCW 71 1 0.5 Y TWCW 71 84 TWCW 72 7 0.7 Y TWCW 72 85 TWCW 73 0.3 N 86 TWCW 74 5 0.4 Y TWCW 74 87 TWCW 75 1 0.1 N 88 TWCW 76 9 0.7 Y TWCW 76 89 TWCW 77 1 6.9 Y TWCW 77 90 TWCW 78 7 0.4 Y TWCW 78 91 TWCW 79 3 1 Y TWCW 79 92 TWCW 80 2 0.4 Y TWCW 80 93 TWCW 81 3 1.5 N 94 TWCW 82 8 0.9 Y TWCW 82 71

95 TWCW 83 3 1.5 Y TWCW 83 96 TWCW 84 3 0.6 Y TWCW 84 97 TWCW 85 3 2.3 Y TWCW 85 98 TWCW 86 8 1 Y TWCW 86 99 BWW 75 11 2.6 N 100 BWW 76 1 2.8 N 101 BWW 77 7.7 N 102 BWW 78 3 12 N 103 BWW 79 0.4 N 104 BWW 80 0.2 N 105 BWW 81 1.3 N 106 BWW 82A 2 1 N 107 BWW 82B 0.1 N 108 BWW 82C 2 1 N 109 BWW 82D 0.3 N 110 BWW 83 10 5.5 Y TW 91-93 111 BWW 84 1.2 N 112 BWW 85 2 1.2 N 113 BWW 86 0.8 N 114 BWW 87 1 9 N 115 BWW 88 8 0.65 Y TH-E-1 116 BWW 89B 2.1 N 117 BWW 89C 0.9 N 118 BWW 89D 1 0.4 N 119 BWW 89E 0.4 N 120 BWW 90 1 2.5 N 121 BWW 91 8 0.6 Y TH-E-5 122 BWW 92 11 1.2 Y TH-E-6 123 BWW 93 1 2.5 N 124 BWW 94 9 0.8 Y TH-E-9 125 BWW 95 2 5.5 Y TH-E-10 126 BWW 96 7 1.3 Y TH-E-11 127 BWW 97 1 4.5 Y TH-E-12 128 BWW 98 2.5 N 129 BWW 99A 1 5 N 130 BWW 99B 9 0.6 Y TH-E-16 131 BWW 99C 1 1.5 N 132 WW 37 3 1.3 Y TW 98B 133 WW 38 10 1.1 Y TW 99T 134 WW 39 1 0.4 N 135 WW 40 9 3.3 Y TH-E-19 136 WW 41 1.4 N 137 WW 42 4 6 Y TH-CS-12 138 WW 43 8 2.4 Y TH-CS-11 139 WW 44 1 4.5 N 140 WW 45 2.1 N 141 WW 46 1 2.7 N 142 WW 47 1 1.2 N 72

143 WW 48 1 4.4 N 144 WW 49 0.6 N 145 WWU 139 5 1.7 Y TW 120 146 WWU 140 11 6 Y TW 121 147 WWU 141 6 0.6 Y TW 122 148 WWU 142 2 9.3 N 149 WWU 143 2 2.2 Y TW 124 150 WWU 144 1.1 N 151 WWU 145 2 1.5 N 152 WWU 146 8 1 Y TW 135 153 WWU 147 11 0.4 N 154 WWU 148 2 5.2 N 155 WWU 149 1.1 N 156 WWU 150 2 3.5 N 157 WWU 151 1.1 N 158 WWU 152 11 0.5 N 159 WWU 153 2 3.3 N 160 WWU 154 11 3 Y TW 154 161 WWU 155 1.5 N 162 WWU 156 2 8.3 N 163 WWU 157 0.9 N 164 WWU 158 0.45 N 165 WWU 159 2 4 N 166 WWU 160 11 0.8 N 167 WWU 161 1 5.4 N 168 WWU 162 0.7 N 169 WWU 163 2 2 N 170 WWU 164 0.7 N 171 WWU 165 1 N 172 WWU 166 2 1.8 N 173 WWU 167 0.7 N 174 WWU 168 1 N 175 WWU 169 1.3 N 176 WWU 170A 2 0.6 N 177 WWU 170B 1 N 178 WWU 170C 2 0.4 N 179 WWU 171 1 N 180 WWU 172 2 3 N 181 WWU 173 11 0.8 N 182 WWU 174 0.4 N 183 WWU 175 2 3 N 184 WWU 176 11 2 N 185 WWU 177 2 6 N 186 WWU 178 4 4.3 Y TW 160B 187 WWU 179 10 1.2 Y TW 161M 188 WWU 180 10 1.7 Y TW 161T 189 WWU 181 2 3 N 190 WWU 182 11 3 N 73

191 WWU 183 1 N 192 WWU 184 2 6 N 193 WWU 185 1.7 N 194 WWU 186 0.5 N 195 WWU 187 0.5 N 196 WWU 188 2 9.1 Y TW 163M 197 WWU 189 11 0.9 N 198 WWU 190 0.3 N 199 WWU 191 11 0.2 N 200 WWU 192 2 3 N 201 WWU 193 0.5 N 202 WWU 194 0.6 N 203 WWU 195 2 1.3 N 204 WWU 196 0.6 N 205 WWU 197A 2 1.5 N 206 WWU 197B 9 1 Y TW 166 207 WWU 197C 2 0.5 N 208 WWU 198 11 4.5 N 209 WWU 199 1.5 N 210 WWU 200 2 1.3 N 211 WWU 201 0.5 N 212 WWU 202 2 4.2 N 213 WWU 203 0.6 N 214 WWU 204 1 N 215 WWU 205 11 0.6 N 216 WWU 206 11 0.4 N 217 WWU 207 2 0.4 N 218 WWU 208 0.4 N

Total Thick 425.4 % TS Coverage 40.4 # TS 88 # Assigned MF 166 Assigned MF Thick 374.55 % Assigned Coverage 88.0 % Unassigned 12.0

MF 1: Anaerobic Mudstone

# Units 37.0 # TS (Y) 6 % TS Coverage 16.2 Thickness 137.05 % MF Representation 36.6

MF 2: Dysaerobic Spiculite Mudstone

Total Thickness 118.1 % MF Representation 31.5 # Units 45.0 # TS (Y) 17 % TS Coverage 37.8

MF 3: Dysaerobic Sparse Skeletal Wackestone

Total Thickness 24.55 % MF Representation 6.6 # Units 10.0 # TS (Y) 8 % TS Coverage 80.0

MF 4: Aerobic Mudstone to Sparse Skeletal Wackestone

Total Thickness 10.5 % MF Representation 2.8 # Units 3.0

MF 5: Skeletal Wackestone

Total Thickness 6.7 % MF Representation 1.8 # Units 8.0

MF 6: Mud-dominated Skeletal Packstone

Total Thickness 0.75 % MF Representation 0.2 # Units 3.0

MF 7: Wackestone Caprock

Total Thickness 2.9 % MF 0.8 75

Representation # Units 5.0

MF 8: Skeletal Packstone Caprock

Total Thickness 11.75 % MF Representation 3.1 # Units 10.0

MF 9: Mixed Grain Packstone to Grainstone Caprock

Total Thickness 11.3 % MF Representation 3.0 # Units 11.0

MF 10: Tidalite Caprock

Total Thickness 17.65 % MF Representation 4.7 # Units 14.0

MF 11: Sandstone

Total Thickness 33.7 % MF Representation 9.0 # Units 20.0 # TS (Y) 3 % TS Coverage 15.0

APPENDIX C

Thin Section Images