INFORMATION TO USERS This manuscript has been reproduced from the microShn master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UM I directly to order. UMI A Bell & Howell Information Company 300 North Zeeb Road, Ann Arbor MI 48106-1346 USA 313/761-4700 800/521-0600 MIDDLE-UPPER CAMBRIAN TRILOBITE BIO STRATIGRAPHY OF SLOPE DEPOSITS, PAIBI, WESTERN HUNAN PROVINCE, CHINA DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Gregory J. Wasserman ***** The Ohio State University 1999 Dissertation Committee: Approved by Dr. Loren E. Babcock Dr. William I. Ausich Adviser Dr. Lawrence A. Krissek Department of Geological Sciences Dr. Douglas E. Pride X3MI N um b er: 9931696 UMI Microform 9931696 Copyright 1999, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 ABSTRACT A stratigraphie section through limestones and siliciclastic mudrocks near the village o f Paibi, western Hunan Province, China, is under consideration as the international stratotype for the Middle-Upper Cambrian boundary. This dissertation involves detailed study of the biostratigraphy of non-agnostoid trilobites from the Paibi section, and interpretation of biostratigraphic patterns. The position of Middle-Upper Cambrian boundary is currently undecided, but is likely to be placed at the first appearance worldwide of the agnostoid trilobite Glyptagnostus reticulatus. In North America, the base of the Glyptagnostus reticulatus Interval-zone corresponds to the base of the Pterochepaliid Biomere. A biomere is a stratigraphie interval whose base is identified by an evolutionary radiation and whose top is marked by a mass extinction event. Biomeres are assumed to have worldwide significance (although they are best studied in North America), and the bases of biomeres are assumed to represent post-extinction recoveries. The Paibi section, China, records one of the most complete successions of Middle-Upper Cambrian strata known anywhere in the world. The section represents a slope environment adjacent to the Yangtze (South China) Platform. Because of its completeness, and its paleogeographic position, it offers an excellent opportunity to test for biomere patterns outside Laurentia (ancestral North America-Greenland), and in a shelf-margin environment. The characteristic “biomere” pattern of relatively slow evolutionary diversification followed by rapid mass extinction is not evident in the Piabi section. One possibility for this is that a rise in sea level or a rise in a thermocline and inundation of the shelf with cold or dysoxic water would have pronounced effects in a shelf environment but little effect in a slope environment. A more likely possibility involves downslope movement and resedimentation of trilobite sclerites through gravity displacement on the slope. Many species’ apparent ranges would have extended beyond their true ranges, effectively obscuring any sharp biostratigraphic boundary that may have existed and that may have been retained, in shallow, nearly horizontal, shelf strata. Ill ACKNOWLEDGMENTS Many people have helped or encouraged me in my Ph.D. work. I would like to thank my adviser, Dr. Loren E. Babcock, for taking a chance on me and allowing me to follow a dream I have always had. Without his help, encouragement, and support, I would not have finished. I cannot put into words how much I learned and grew both as a person and a scientist under him. I would also like to thank my committee members, Drs. William I. Ausich, Lawrence A. Krissek, and Douglas E. Pride. Their doors were always open to talk about my project and they always were willing to listen while I bounced ideas off of them. Dr. Stephen Jacobson offered me not only a tremendous amount of encouragement, but he also helped me to organize my work load. He critiqued some of my earlier drafts and offered advice on writing style. This project was funded in part by National Science Foundation grants to Richard A. Robison (subcontract to Loren E. Babcock) and Margaret N. Rees. Additional funds in support of this work came from the China National Natural Science Foundation (awarded to Shanchi Peng and Wentang Zhang), and a Seed Grant from The Ohio State University (awarded to Loren E. Babcock); and National Science Foundation grant EAR-9405990 (awarded to Loren E. Babcock). IV Samples used in this study were collected by Loren E. Babcock, Margaret N. Rees, Richard A. Robison, Shanchi Peng, Wenteng Zhang, Kunli Luo, and H. L. Lin. I am indebted to Dr. Shanchi Peng. I was fortunate enough to work closely with him for several months. He brought numerous rare publications to my attention and a wealth of knowledge of trilobites from my study area. Dr. Allison R. “Pete” Palmer was always willing to answer any questions I have had about biomeres, and provided much information by e-mail. I would also like to thank James St. John. He was always willing to loan publications to me and to lend an ear to any ideas I may have had. We had long discussions on trilobites and paleontology in general, talks in which I learned a tremendous amount of information. I need to mention my best friends, Jeff Rudnicki and Steve Macy, two individuals who provided encouragement when I needed it. Finally, I must thank my parents, Jim and Connie Wasserman, and grandparents, Leonard and Rita Matuszak, for their financial and emotional support, without which I could not have finished this work. VITA May 16, 1967 ..................................... Bom -Toledo, Ohio 1990.....................................................B.S., Geology, Bowling Green State University 1990-1992.......................................... Graduate Teaching Assistant Michigan State University 1994.....................................................M.S., Geology, Michigan State University 1993-1997.......................................... Graduate Teaching and Research Assistant The Ohio State University FIELDS OF STUDY Major Field: Geological Sciences VI TABLE OF CONTENTS Page Abstract ............................................................................................................................. ii Acknowledgements .............................................................................................................. iv Vita........................................................................................................................................ vi List of Figures.................................................................................................................. ix List of Figures.................................................................................................................. x Chapters: 1. Introduction............................................................................................................... I 2. Study Area ................................................................................................................ 9 3. Regional Geologic Setting....................................................................................... 10 Tectonic Blocks in China...................................................................................... 10 Paleogeographic-Lithofacies Belts in South China........................................... 11 Relationship Between Paleogeographic-Lithofacies Belts and Trilobite Biogeography........................................................................................................ 13 Sea Level Trends .................................................................................................... 14 4. Stratigraphy and Sedimentology............................................................................. 19 Lithostratigraphy and Sedimentology of the Paibi Section............................... 19 Biostratigraphy....................................................................................................... 21 Depositional Environments.................................................................................. 23 Modes of Occurrence of Trilobites in the Paibi Section.................................... 24 5. Trilobite Biogeography and Bio faces...................................................................