A geological evaluation of mineralization at Mineral Mountain, Washington County, Utah Item Type text; Thesis-Reproduction (electronic); maps Authors Eliopulos, George James, 1949- 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 28/09/2021 16:01:41 Link to Item http://hdl.handle.net/10150/566536 A GEOLOGICAL EVALUATION OF MINERALIZATION AT MINERAL MOUNTAIN, WASHINGTON COUNTY, UTAH by George James Eliopulos A Thesis Submitted to the Faculty of the DEPARTMENT OF MINING AND GEOLOGICAL ENGINEERING In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN GEOLOGICAL ENGINEERING In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 7 4 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of re­ quirements 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 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 head of the major department or the Dean of the Graduate College when in his judg­ ment the proposed use of the material is in the interests of scholar­ ship. 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: /& + '/ 2 C / ' f 7 ¥ WILLIAM C . PETERS r 'b a te Professor of Mining and Geological Engineering ACKNOWLEDGMENTS I am deeply indebted to Mine Finders, Inc., who generously provided support for this investigation. Special appreciation is extended to Dr. Stewart R. Wallace, President, Mine Finders, Inc., for his per­ sonal interest in the project. Dr. Paul S. Taylor, who accompanied me to the field at various times, is gratefully thanks for his helpful guid­ ance and encouragement. Dr. Richard V. Wyman, Engineering Depart­ ment, University of Nevada, Las Vegas, provided useful information about the Beauty Knoll halloysite deposite. Dr. William C . Peters, thesis director, is gratefully acknowl­ edge for his guidance and interest. The contributions of Drs. Spencer R. Titley and DeVerle PI Harris of my thesis committee are acknowl­ edged. Dr. Dietmar Schumacher, Department of Geosciences, The Uni­ versity of Arizona, kindly identified microfossils and offered helpful a d v ic e . Special thanks are also given to the Bud Nielson family of Motoqua, who helped make my stay in the field a pleasant one. iii TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS.......................................................................... vi ABSTRACT...................................................................................................... v iii 1. INTRODUCTION.......................................................................................... 1 Location .... Previous Work Procedure . , Regional Geologic Setting . Bull Valley Mountains Pine Valley Mountains Iron Springs District . Local Geologic Setting . 00 vj vj O 4^ ^ GO i—» 2 . GENERAL GEOLOGY.................................................................................... 11 Sedim entary R ocks.............................................................................. 11 C allv ille L im esto n e................................................................. 11 Stratigraphy ....................................................................... 12 Age R e la tio n sh ip .............................................................. 15 Claron Formation....................................................................... 16 Stratigraphy ......................... ......................................... 16 Position in T im e .............................................................. 17 Intrusive Igneous R o c k s .............................................. 18 Extrusive Igneous R o c k s................................................................. 22 Isom Form ation........................................................................... 25 V esicular F lo w ................................................................. 25 H o le-in -th e-W all T u f f .................................................. 25 Q uichapa F orm ation................................................................. 26 Leach Canyon and Bauers T uffs ............................... 27 Little Creek B reccia........................................................ 32 B asalt M e m b er........................................................................... 32 3. STRUCTURAL GEOLOGY.............................................................................. 35 Thrust Faulting in W ashington C o u n ty ...................................... 35 Iron Springs Gap and Kanarra-Virgin Anticlines .... 35 Castle Cliff Thrust ................................................................. 36 Interpretation .................................................................... 38 Lateral E x ten t..................................................................... 39 iv v • TABLE OF CONTENTS—Continued Page Post-Laramide Igneous Intrusion at Mineral Mountain . 41 Development of the Mineral Mountain Laccolith. 41 Level of Em placem ent..................................................... 44 A ssociated F a u ltin g ........................................................ 45 Space-Time Relationships of Plutonism at Mineral Mountain.................. 48 Aeromagnetic Studies ................................................................ 52 4. ECONOMIC GEOLOGY....................................................................... ... 55 Mineralization at Mineral M ountain ........................ 56 Peripheral Shell R o ck .............................................................. 57 Description ....................................................................... 57 Petrography and A lteration............................................ 60 C ontact M etam orphosed R o c k ............................................. 62 Comparison of Mineral Mountain and Iron Springs In tru sio n s.......................................................................................... 63 5 . GEOCHEMICAL ROCK SURVEY........................................ 67 Geochemical Distribution by Rock Type .................................. 69 C o p p e r................................................................. .' ..................... 70 M olybdenum ................................................................................ 70 L ead................................................................................................ 71 Z in c ................................................................................................ 72 6 . GUIDES TO FUTURE EXPLORATION........................................................ 73 7. CONCLUSION................................................................................................ 75 APPENDIX: GEOCHEMICAL DATA........................................................ 76 REFERENCES.......................................................... 80 LIST OF ILLUSTRATIONS Figure Page 1. Location map showing geographic location of Mineral Mountain and its relation to the Bull Valley, Pine Valley, and Iron Springs a r e a s ............................................... 2 2. Geologic map of Mineral Mountain area, Washington C ounty, U t a h ........................................................................in pocket 3 . Areas mapped in southw estern U tah ............................................ 5 4. Block of light-colored Callville limestone dipping off the southern flank of Mineral Mountain............................... 9 5. Photomicrograph of a quartz phenocryst from Mineral Mountain quartz monzonite porphyry..................................... 20 6. Photomicrograph of veinlet-controlled K-feldspathic alteration destroying twin planes of a plagioclase p h e n o c ry s t...................................................................................... 23 7. Photomicrograph of ve inlet-controlled K-feldspathic alteratio n in albite p h e n o cry sts............................................... 23 8. Color contrast between ridge-forming "purple por­ phyry" and slope-forming "white porphyry" units in Butcher Knife Canyon.............................................................. 28 9. Photomicrograph of strongly re sorbed quartz pheno­ cryst (q) and broken plagioclase grains (p) set in a glassy to microcrystalline groundmass............................ 28 10. Photomicrographs of tricuspate and curviplanar shards from the Quichapa formation in Butcher Knife Canyon....................................................................... ... 30 11. Photomicrograph depicting axiolitic texture of devitrified g la ss fragm ents........................................................ 31 12. Photomicrographs of coarse-grained olivine pheno­ cryst with poikilitic inclusions of magnetite (black sp e c k s )................................................................................. 34 13. Cross sections of Mineral Mountain area, Washington County, U t a