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And Sequence Stratigraphy of the Middle Cambrian Spence Shale of Northern Utah and Southern Idaho

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And Sequence Stratigraphy of the Middle Cambrian Spence Shale of Northern Utah and Southern Idaho Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 12-2011 The Interrelationship Between the Bio- and Sequence Stratigraphy of the Middle Cambrian Spence Shale of Northern Utah and Southern Idaho Eva Lyon Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Geology Commons Recommended Citation Lyon, Eva, "The Interrelationship Between the Bio- and Sequence Stratigraphy of the Middle Cambrian Spence Shale of Northern Utah and Southern Idaho" (2011). All Graduate Theses and Dissertations. 1117. https://digitalcommons.usu.edu/etd/1117 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. THE INTERRELATIONSHIP BETWEEN THE BIO- AND SEQUENCE STRATIGRAPHY OF THE MIDDLE CAMBRIAN SPENCE SHALE OF NORTHERN UTAH AND SOUTHERN IDAHO by Eva Lyon A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Geology Approved: _______________________ _______________________ W. David Liddell Carol Dehler Major Professor Committee Member _______________________ _______________________ Peter Kolesar Mark R. McLellan Committee Member Vice President for Research and Dean of the School of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2011 ii Copyright © Eva Lyon 2011 All Rights Reserved iii ABSTRACT The Interrelationship Between the Bio- and Sequence Stratigraphy of the Middle Cambrian Spence Shale of Northern Utah and Southern Idaho by Eva Lyon, Master of Science Utah State University, 2011 Major Professor: W. David Liddell Department: Geology The Middle Cambrian Spence Shale Member of the Langston Formation of northern Utah and southern Idaho is a fossil-rich unit that exhibits distinct cyclicity at the parasequence (meter) scale. At least seven discrete, shallowing-upwards parasequences, or cycles, can be found at the Miners Hollow and Antimony Canyon localities, each composed of calcareous shale capped by limestone. Within each cycle and within the member as a whole, predictable patterns of faunal distribution are evident. Sampling and identification of fossils from two localities have revealed that observed changes in fauna track changes in sea level throughout the section. Through cluster and principal components analyses it has been determined that those rocks of the Spence Shale representing a transgressive systems tract are home to a particular community of organisms, while those rocks of the highstand systems tract are home to another. It logically follows that the rocks of the transgressive tract represent a distinct biofacies, iv while those of the highstand tract represent another. The transgressive biofacies is composed of species such as agnostid and oryctocephalid trilobites and inarticulate brachiopods that are commonly found in deeper ramp settings. The highstand biofacies is distinguished by such taxa as Zacanthoides and other larger trilobite genera such as Glossopleura and Kootenia, and the eocrinoid Gogia, among others. The difference in ramp position between the Miners Hollow and Antimony Canyon localities implies a water depth gradient, with Antimony Canyon representing shallower water and Miners Hollow representing deeper water. This relationship is also reflected in the biofacies and community assignments. The stratigraphic trends explored in this study may be applied to other Spence Shale localities and possibly other Cambrian fossil deposits, such as the Burgess Shale of British Columbia. (151 pages) v PUBLIC ABSTRACT The Interrelationship Between the Bio- and Sequence Stratigraphy of the Middle Cambrian Spence Shale of Northern Utah and Southern Idaho Eva Lyon 2011 This project was undertaken with the objective of discerning the relationship between sea level change and changes in the fauna of the Spence Shale. A combination of field and lab work was employed to undertake this research. The Spence Shale is rich in fossils from the earliest period of visible life on this planet. It provides a unique window onto the evolution of life and changes in the Earth at this time. It is important to study this relationship between sea level and life changes as these conditions are constantly changing, particularly in this day and age. A better understanding of these conditions may help us prepare for future changes to this planet. The research was relatively inexpensive to perform, as all materials required for analyses were readily available in the Geology Department at Utah State University or through the help of colleagues. The only area of cost was a consequence of travelling to the field area in the Wellsville Mountains, but this was negligible. Given the knowledge gained in through this project, it was well worth any costs incurred. vi ACKNOWLEDGMENTS In my time at Utah State University, I have come to appreciate the opportunity to learn new things, not only in the classroom and field, but also about myself and the world around me. Living in Utah has been a truly informative experience, and I am glad to have had exposure to such a unique environment. I am also grateful to those who have supported me along the way, not least of which being my committee members, Drs. Carol Dehler and Pete Kolesar, who graciously provided their expertise to this project. I am also grateful to my friends, who helped keep me sane, and occasionally aided in my field work. Also, without the insights of Paul Jamison and Val and Glade Gunther, I would have been adrift in a sea of trilobites. Finally, I must thank my advisor, Dr. W. David Liddell, whose guidance and patience helped get me through the trials and tribulations of a master’s thesis. Eva Lyon vii CONTENTS Page ABSTRACT ..........................................................................................................................iii PUBLIC ABSTRACT ...........................................................................................................v ACKNOWLEDGEMENTS...................................................................................................vi LIST OF TABLES.................................................................................................................ix LIST OF FIGURES ...............................................................................................................x INTRODUCTION .................................................................................................................1 Geology of the Spence Shale.....................................................................................1 Overview of Sequence Stratigraphy ..........................................................................5 Previous Work ...........................................................................................................12 METHODS............................................................................................................................19 Field Methods ............................................................................................................19 Other Sampling Methods...........................................................................................19 Laboratory Methods...................................................................................................20 RESULTS..............................................................................................................................23 Antimony Canyon Data .............................................................................................23 Miners Hollow Data ..................................................................................................33 Merged Data Sets – Localities Combined .................................................................53 Compared Data Sets – Localities Separate................................................................67 DISCUSSION........................................................................................................................83 Antimony Canyon Data .............................................................................................83 Miners Hollow Data ..................................................................................................86 Merged Data Sets – Localities Combined .................................................................89 Compared Data Sets – Localities Separate................................................................90 General Trends...........................................................................................................91 CONCLUSIONS ...................................................................................................................97 REFERENCES ......................................................................................................................99 viii APPENDICES .......................................................................................................................106 Appendix A. Tables of Collection Data ....................................................................107 Appendix B. MVSP Analysis Data ...........................................................................114 Appendix C. Supplemental Figures and Data............................................................127 ix LIST OF TABLES Table Page A.1 Antimony
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