Biochronology and magnetostratigraphy of the Pliocene Panaca Formation, southeast Nevada Item Type text; Dissertation-Reproduction (electronic) Authors Mou, Yun Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 03/10/2021 23:29:29 Link to Item http://hdl.handle.net/10150/284594 INFORMATION TO USERS This manuscript has been reproduced from the microfilm 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. 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Contact UMI directly to order. Bell & Howell Information and Learning 3CX) North Zeeb Road, Ann Arbor, Ml 48106-1346 USA 800-521-0600 NOTE TO USERS This reproduction is tlie best copy available UMI BIOCHRONOLOGY AND MAGNETOSTRATIGRAPHY OF THE PLIOCENE PANACA FORMATION, SOUTHEAST NEVADA by Yun Mou Copyright ®Yun Mou 1999 A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College The University of Arizona 1999 UMI Nvunber: 9934864 Copyright 1999 by Mou, Yun All rights reserved. UMI Microform 9934864 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 2 THE UNIVERSITY OF ARIZONA ® GRADUATE COLLEGE As members of the Final Examination Committee, we certify that we have read the dissertation prepared by Yun Mou entitled BIOCHRONOLOGY AND MAGNETOSTRATIGRAPHY OF THE PLIOCENE PANACA FORMATION, SOUTHEAST NEVADA and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy i. 'fff Date / •Jhite Date Robert F. Butler Date Z.^ fdticj I9?9 Russell^^is Date ] Yar ^etryszyn^ Date Final approval and acceptance of this dissertation is contingent upon the candidate's submission of the final copy of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. Dissertation Director Everett H. Lindsay Date/ 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the copyright holder. SIGNED: 4 ACKNOWLEDGMENT This dissertation could not have been finished without the help from many people. I first thank my dissertation director, Dr. Everett H. Lindsay, who patiently guided my graduate studies and supported this research. I am gratefiil for his initiation of this project and for great help in the field. I thank Dr. John A. White for his encouragement and allowing me to use his library. I learned the unique methods of studying rabbits from him, and I am grateful to him for making many of the drawings of rabbit teeth that I have placed into this dissertation. I would also like to give my appreciation to Dr. Robert F. Butler, who let me conduct the paleomagnetic lab work in his state-of-the-art laboratoiy, guided my work step by step, and provided me with detailed suggestions on the magnetostratigraphy chapter. I am gratemi to Dr. Russell Davis for his encouragement and help on my biology courses. I also thank Dr. Yar Petryszyn who encouraged me on this research and provided me with convenient assistance when I examined the specimens at the UA Mammal Collection. I am thankful to each of my committee members for their critical reading an earlier draft of this dissertation. Many people worked with me in the field. I am very grateful to William R. Downs, Kevin F. Dovming, Lisa E. Park, Lois J. Roe, Kelly Iris, Jessica H. Harrison, Emily E. Erickson, and Curt Lindsay. I especially thank Dr. Oldrich Fejfar and Ms. Carole Pederson, who found the two important fossil sites, UALP 9504 and 9702. I also thank Tank Ojha for his help on collecting paleomagnetic samples in the field. The BLM office of Caliente provided facilities for our screen washing. Laboratory technicians at the Department of Geosciences, Kevin B. Moodie and Wesley Bilodeau, helped me in the preparation of SEM samples. I thank Dr. Andrew Cohen for allowing me to use his image lab. I am grateful to David Bently at the image lab of the Department of Ecology and Evolutionary Biology for his help with the examination of samples under the SEM. Students at the paleomagnetic lab gave me help on demagnetizing samples and formatting results; I would like to thank Julie Libarkin, David Richards, and Guillaume Dupont-Nivet. I thank Joel L. Pederson at the University of New Mexico who processed the ashes we collected and sent them to the Tephrachronology lab of U. S. Geological Survey (USGS) for dating. I thank Dr. Richard H. Tedford for his generosity in providing me the notes on the mammal fossils from Panaca in the American Museum of Natural History collection. Charles A. Repenning provided consultation on the microtine rodents. Dr. Andrei Sama-Wojcicki with the Tephrachronology lab of USGS chemically correlated the ash from Panaca; he and Dr. Robert Fleck kindly permit me to cite their unpublished Healdsburg tuff age in this dissertation. My parents have been an encouraging source for me since I started my student career. I thank them for their understanding and support. I especially thank my husband, Chao Yang Zheng, who has always encouraged me and been a great help for me throughout my graduate study. This research was supported by the NSF grant EAR 9526386 and the Summer Research Support from the Department of Geosciences, University of Arizona. 5 This dissertation is dedicated to my husband, Chao Yang Zheng, and to my parents, Qi Fang Mou and Yuan Ling You. 6 TABLE OF CONTENTS LIST OF ILLUSTRATIONS 10 LIST OF TABLES 17 ABSTRACT 21 CHAPTER 1. INTRODUCTION 23 1.1 Biochronology and land mammal age principles 23 1.2 Criteria on the definition of a boundary between two adjacent land mammal ages 24 1.3 Current status of Hemphillian-Blancan boundary 26 CHAPTER 2. GEOLOGICAL SETTING AND PREVIOUS STUDIES 30 2.1 Geological setting of Panaca Formation in southeast Nevada 30 2.2 Previous studies on mammal fossils from Panaca Formation 35 CHAPTER 3. STUDY METHODS AND ABBREVIATIONS 38 3.1 Study methods 38 3.2 Abbreviations 40 CHAPTER 4. SYSTEMATIC PALEONTOLOGY 42 4.1 Order Insectivora Cuvier, 1817 42 Family Soricidae Vacq'd'Azyr, 1792 42 Subfamily Soricinae Fisher von Waldheim, 1817 43 Parcmotiosorex gen. nov 43 Parcmotiosorex panacaensis gen. and sp. nov 44 Neomyini gen. and sp. indet 55 Sorex meltoni Uihhard, 1956 58 4.2 Order Lagomorpha 62 Family Leporidae Gray, 1821 62 Subfamily Archaeolaginae Dice, 1929 64 H)j)oIagus edensis Vrick, 1921 64 Hypolagus cf. H. edensisFrick, 1921 65 Hypolagus tedfordi White, 1987 66 TABLE OF CONTENTS— Hypolagus cf. H. ringoldensis Gustafson, 1978 .. 7Hypolagus ringoldensis Gustafson, 1978 Hypolagus cf. H. gidleyi White, 1987 Hypolagus cf. H. regalis EBbbard, 1939a Pewelagus dawsonaeV^hiiQ, 1984 Lepoides lepoides'^\i\XQ, 1987 ILepoides lepoides White, 1987 Subfamily Leporinae Trouessart, 1880 Nekrolagus progressus sp. White, 1991 4.3 Order Rodentia Family Geomyidae Bonaparte, 1845 Subfamily Geomyinae Bonaparte, 1845 Pliogeomys parvus Zdkiz&NsVi, 1969 IPliogeomys sp Family Heteromyidae Allen and Chapman, 1893 Subfamily Perognathinae Wood, 1935 Perognathus mclaughlini Bihhaid, 1949 Werogmihus mclaughlini Oregonomys sp ICupidinimus sp Subfamily Dipodomyinae Coues, 1875 Prodipodomys minor Gidley, 1922 IProdipodomys minor ProdipodomystiheniWahdiXd, 1943 IProdipodomys tiheni Family Cricetidae Rochebrune, 1883 Subfamily Sigmodontinae Peromyscus hagermanensisWohdtxd, 1962 Onychomys spp Repomys Mdiy, 1981 Repomyspanacaensisyixy, 1981 Repomys minor sp. nov Subfamily Arvicolinae Gray, 1882 Mimomys panacaensis Subfamily ftometheomyinae Kretzoi, 1955 ... Nevadomys n. gen Nevadomys fejfari gen. and sp. nov Nevadomys cf. N. fejfari gen. and sp. nov 8 TABLE OF CONTEmS—Continued Nevadomys lindsayi gen. and sp. nov 217 Nevadomys downsi gen. and sp. nov 224 4.4 Order Camivora Bowdich, 1821 238 Family Procyonidae Gray, 1825 238 Bassariscus caseiYiMiSxdi, 1952 238 IBassariscus caseiYUhhzxA, 1952 242 Family Canidae Fisher de Waldheim, 1817 243 Canis sp 243 Camivora, family, gen. and sp. indet 244 CHAPTER 5. SCHMELZMUSTERS OF MIMOMYS AND NEVADOMYS (NEW GENUS) FROM THE PANACA LOCAL FAUNA 247 5.1 Introduction and study method 247 5.2 Mimomys panacaensis Mou, 1997 251 5.3 Nevadomys fejfari, n.