Fusulinids and conodonts of a Pennsylvanian- Permian section in the northern Dragoon Mountains, Cochise County, Arizona Item Type text; Thesis-Reproduction (electronic); maps Authors Micklin, Richard Francis, 1945- 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 04/10/2021 07:33:41 Link to Item http://hdl.handle.net/10150/552069 PUSULIKIDS AND CONODONTS OF A PENNSYLVANIAN-PERMIAN SECTION IN THE NORTHERN DRAGOON MOUNTAINS, COCHISE COUNTY, ARIZONA by Richard Francis Micklin A Thesis Submitted to the Faculty of the DEPARTMENT OF GEOLOGY In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 1969 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfill­ ment 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 thesis are allowable without special permission, provided that accurate acknow­ ledgment 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 head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: tXZ D. L. BRYANT c7 Date Professor of^Geology ACKNOWLEDGMENTS The author is extremely grateful for the encourage­ ment and financial aid received from his parents, Mr. and Mrs. Frank Micklin. The author also wishes to express his gratitude for the receipt of an NDEA IV Fellowship without which this thesis would not have been possible. Thanks are due to Dr. Donald L. Bryant, thesis director, for his guidance and prompt assistance through­ out the duration of this project. Dr. Joseph F. Schreibor, Jr. also field checked the thesis and offered helpful suggestions concerning carbonate petrography. Thanks are also due to Dr. James N. Gundersen who critically read the manuscript. Hearty-thanks are due to ray wife, Marcia, without whose help and encouragement this thesis would not have been completed. ill TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS vi ABSTRACT.............................. ................ viii INTRODUCTION........................................... 1 General Statement........ 1 Location............................. 1 Purpose and Scope of the Investigation..... ...... 2 Previous Work....................... 3 Field Methods and Laboratory Techniques......... 5 GENERAL GEOLOGY......................... 9 General Scatement.................a............... 9 Formational Boundaries............................ 9 Stratigraphy of the Measured Section.............. 13 Horqullla Limestone.......................... 13 Lower Mas siv e vi ember.................... Interbcdded Slope-forming Member........ U Middle Massive Member.... .............. 14 Massive Cliff-forming Member........... Upper Interbeddcd Member........... Earp Formation............................... Lower Limestone Member........... Middle Terrigenous Member............... Upper Interbeddcd Member.......... Environment of Deposition.............. Horqullla Limestone..... ................ Earp Formation..................... .......... FUSULINID EQUATION 27 General Statement........................... 2? Previous Work.......................... 29 Fusulinld Zones........ 30 Fusullnella Concurrent-range Zone....... 32 Boedelna Concurrent-range Zone....... 33 Trltlcites Concurrent-range Zone............. 37 Leptotriticites Concurrent-range Zone........ 40 Fusulinld Zona t ion summary............ ........... 42 iv V TABLE OF CONTENTS— Continued x Page CONODONT ZONATIOH....... 45 General Statement................................ 45 Previous v/orlc. .♦•.•••...♦•♦♦..eo.................. 46 Conodont Zones...... 4? Morrovran........ 48 Derryan...................................... 50 Desmoinesian.... ............ 51 Missourian............. 54 Virgillan....... 55 Wolfcampian............ 56 CONCLUSIONS................ 57 SYSTEMATIC PALEONTOLOGY•............................... 60 Order FORAMINIFERIDA 6o Genus Plectofusullna....... 60 Genus Fusulinella............... 64 Genus WedeklndeTTlna......................... 71 Genus Boedelna............ 83 Genus Tritlcltes...... ...................... 103 Genus Lep to tritlcl tes.......... 126 Genus Schwagerina........ 133 Order CONODONTOPHORIDA 136 Genus Adetognathus.... 136 Genus Gnathbdus....... 146 Genus Idlognathodus♦.. 151 Genus Idlognatholdes«. 160 Genus Strcptognathodus 163 Genus UNDESCRIBED.... 173 Genus Hindeodella.•..• 175 Genus Llgonodlna...«.. 181 Genus Ncborloniodus.*. I83 Genus Prionlodus..... 186 Genus Spathognathodus♦ 188 Genus Gondolella...... 200 APPENDIX I: MEASURED SECTION: NORTHEASTERN DRAGOON MOUNTAINS.......... .............. 218 SELECTED BIBLIOGRAPHY 250 LIST OF ILLUSTRATIONS Figure Page 1. Index map of Arizona showing location of northern Dragoon Mountains in northwestern Cochise County............................ 8 2. Local terrane and location of measured section in northern Dragoon Mountains...... 12 3. Fusullnld Occurrence................ in pocket 4. Fusullnld Zones with Related Conodont Ranges..... in pocket 5. Conodont Occurrence^............................ in pocket 6. Plectofusulina and Fusullnella................. 201 ?. Uedcklndolllna.............................. 202 8. Beedelna.... .............. 203 9. Beedelna............................ 204 10. Beedelna.......... 205 11. Beedelna and Trltlcltes........... 206 12. Trltlcltes....................................... 20? 13. Trltlcltes....................................... 208 14. Trltlcltes and Leptotrltloltes.......... 209 15. Leptotrltloltes....... 210 16. Schwagerlna.. ....... 211 1?. Adetognathus.... ............ 212 18. Idlpgnathoides and Idlognathodus................. 213 19. Idlognathodus end Gnathodns........ 214 vi vii LIST OP ILLUSTRATIONS— Continued Figure Page 20, Genua undescribed and Streptognathoduso. 215 21 c Spathognathodus and ?Spathognathodus............ 216 22. Prlonlodus, Neoprlonlodus, ?Neopr1on1odus, Llgonodina, Gondolella, and Hindoodeiia.T........ 21? ABSTRACT In the northeastern Dragoon Mountains the 1481-foot thick Pennsylvanian Horquilla Limestone was deposited in predominantly quiet shallow marine seas with minor influxes of terrigenous material. The 420-foot thick Pennsylvanian- Permian Earp Formation was deposited in the shallower, nearshore, intertidal and supratidal zones which received clastic influxes of deltaic origin from the north. The gradational boundary between the Horquilla Limestone and the Earp Formation was placed 1481 feet above the base of the measured section where massive marine lime­ stones were superceded by more clastic rocks. The Virgilian-Wolfcampian boundary was placed 81 feet above the base of the Earp Formation below the Leptotrltlcltes Zone. Stage and substage boundaries were established on the basis of fusulinids and conodonts were evaluated as time indicators in relation to fusulinids. The Morrowan- Derryan boundary and probably the Desmoinesian-Missourian boundary are best located by changes in conodont faunas. The Derryan-Desmoinesian and the Virgilian-Rolfcampian boundaries are most accurately determined by fusulinids. Significant faunal, changes occur both in the fusulinids and the conodonts near the Missourian-Virgilian boundary. Conodont species were longer ranging and, therefore, less useful in subdividing the stages than arc fusulinids. viii INTRODUCTION General Statement In the northern Dragoon Mountains the Horquilla Limestone and the Earp Formation were deposited in a generally transgressive Pennsylvanian sea and a generally regressive Late Pennsylvan!an-Early Permian sea. A variety of environmental conditions existed through time at this one locality. Horquilla dolomites, shales, and limestones reflect a shallow, unstable shelf subject to weak but occasionally strong currents with minor influxes of fine­ grained terrigenous material. Cross-bedded silty dolo­ mites, shales, and carbonates of the Earn Formation indicate a shallow near-shore marine shelf environment that alternated with a supra-tidal flat environment. Both formations contain an abundant, but often poorly preserved, microfauna consisting of conodonts, fusulinids and other foraminifera, and ostracodes. Location The composite section of Horquilla Limestone and Earp Formation Investigated is located between the Permian Colina Limestone to the west and an Intrusion of Tertiary age to the east in the extreme northeastern Dragoon 1 2 Mountains* This area is located in sections 23 and 26, T. 16 S., R. 23 E., in the Cochise Quadrangle between 109O45’ and 110°00' W. longitude and 32°00* and 32°15' N. latitude. The northern Dragoon Mountains are readily accessible from Interstate 10 by turning south on secondary roads from either the Dragoon, Johnson, or the U.S. 666 exits. Jeep trails terminate within an eighth of a mile of the base of the measured section. Purpose and Scope of the Investigation During most of Pennsylvanian and