AN ABSTRACT OF THE THESIS OF DAVID S. KLANDERMAN forthe degree of MASTER OF SCIENCE in GEOLOGY presented onTfinfl 0,0 MO Title: STRATIGRAPHY, STRUCTURE,AND DEPOSITIONAL ENVIRONMENTS OF THE ANTELOPEMOUNTAIN QUARTZITE, YREKA, CALIFORNIA Redacted for Privacy Abstract approved: Dr. A. J. Boucot The Antelope Mountain Quartziteoccupies approximately 25 square miles at thenorthern tip of the Eastern Klamath Beltof the Klamath mountain geologic province ofnorthern California. The stratigraphic sequence containsapproximately 880 meters of interbedded quartzwacke,shale, muds tone, quartz conglomerate, and bedded chert.The coarse grained clastic material was originally derived from ametamorphic-acid plutonic source terrain, and may have been transported anddeposited by gravity flow processes in a submarinecanyon-fan complex.Shale and mudstone probably represent deposition ofhemipelagic mud during inter- mittant periods when influx of coarsegrained detrital material was low.The bedded chert was formedthrough recrystallization of radiolarian and spiculiferous oozewhich accumulated after significant influx of terrigenous sediment stopped. The age of the chert, and presumably the clastic sediments, can be confined between Middle Cambrian and Middle Mesozoic based on fossil evidence and structural and stratigraphic relationships with the overlying rocks. At least four periods of folding, thrusting, and high angle faulting can be recognized in the Antelope Mountain strata.The contact between the Quartzite and the underlying DuzelPhyllite is marked by a thrust fault.The contact with the overlying Late Cretaceous sedimentary rocks and Tertiary volcanic rocksis defined by an angular unconformity. The Antelope Mountain Quartzite shows no economic potential, except as a possible source of gravel or landfill. Stratigraphy, Structure, and Depositional Environments of the Antelope Mountain Quartzite, Yreka, California by David S. Klanderman A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Tune 1978 APPROVED: Redacted for Privacy Professor of Geology in charge of major Redacted for Privacy Acting Chairman of Department of Geology Redacted for Privacy Dean of GraduateSchoot Date thesis is presented Typed by Lyndalu Sikes for David S. Klanderman ACKNOWLEDGEMENTS Most sincere appreciation is extended to Dr. Arthur J. Boucot, Professor of Geology, Oregon State University, for his guidance, editorial supervision, and financial support for field and laboratory work from NSF Grant DES74-22051. Sincere appreciation is also extended to Mrs. Jane Putnam, and to David Rohr, Dr. Alan Niem, and Dr. J. G. Johnson of Oregon State University for their critical review of the manuscript and many helpful suggestions.I also wish to thank Dr. Jane Gray of the University of Oregon, and Dr. J. Keith Rigby of Brigham Young University for their assistance in the capture and identification of my fossil. Special thanks are due to the people in the thesis area who gave their permission for mapping to be done ontheir property, and to the geologists of the Klamath National Forest who assisted in supplying aerial photographs and maps pertaining to the thesis area. Last but not least, I wish to thank my family, Mr. and Mrs. Cleave land Putnam and Col. and Mrs. Walton Smith, for all their support throughout my long and colorful academic career. TABLE OF CONTENTS Page INTRODUCTION 1 Location and Accessibility 1 Purpose and Methods of Investigation 1 Topography, Climate, and Vegetation 3 Expos ures 4 Previous Work 7 Regional Geology 8 STRATIGRAPHIC DESCRIPTIONS AND DISCUSSION 12 Duzel Phyllite 12 Name 12 Lithology 12 Thickness 17 Contacts 17 Age 17 Depositional Environment and Metamorphism 18 Schulmeyer Gulch Sequence 18 Name 18 Lithology 19 Contacts 19 Thickness and Age 22 Depositional Environment 22 Antelope Mountain Quartzite: General Description 22 Name, Locality, and Extent 22 Stratig raphic Subdivisions 23 Metamorphism 23 Antelope Mountain Quartzite: Lower Quartzwacke Member 24 Name and Type Locality 24 Lithology 24 Thickness 33 Contacts 33 Age 34 Depositional Environment 34 Antelope Mountain Quartzite: Middle Quartzwacke Member 37 Name and Type Locality 37 Lithology 38 Thickness 45 Contacts 45 Page Age 45 Depositional Environment 46 Antelope Mountain Quartzite: Quartz Conglomerate Marker Beds of the Middle Quartzwacke 48 Name and Type Locality 48 Lithology 49 Thickness 53 Contacts 57 Age 57 Depositional Environment 57 Antelope Mountain Quartzite: Bedded Chert Member 59 Name and Type Locality 59 Lithology 60 Thickness 64 Contacts 64 Age 67 Depositional Environment 67 Cretaceous Rocks 70 Name 70 Lithology 71 Thickness 73 Contacts 74 Age 74 Depositional Environment 74 Tertiary (?) Volcanic Rocks 75 Location and Extent 75 Quaternary Alluvium 77 Location and Extent 77 STRUCTURAL DESCRIPTIONS AND DISCUSSION 78 Faults 78 Thrust Faults 78 High-Angle Faults 83 Folds 84 Tectonic History 85 ECONOMIC GEOLOGY 90 REFERENCES CITED 91 APPENDICES 96 LIST OF FIGURES Figure Page 1. Index map showing location of Antelope Mountain and vicinity. 2 2. Topography and outcrops in the northern part of the thesis area. 5 3. Topography and outcrops in the southern part of the thesis area. 6 4. Index map showing study area, subprovinces of Klamath Mountains and adjoining provinces. 9 5. Gravity anomaly in the northern Klamath Mountains. 11 6. Duzel Phyllite in outcrop. 13 7. Photomicrograph of Duzel Phyllite showing offset in a calcite vein. 15 8. Limestone beds of the Schulmeyer Gulch sequence. 20 9. Photomicrograph of the chert conglomerate from the Schulmeyer Gulch sequence. 21 10. Quartzwacke and shale beds from lower member. 26 11. Shale ripups in quartzwacke bed from lower member. 27 12. Photomicrograph of microcline grain and quartz grains in lower member. 29 13. Photomicrograph of lower member quartzwacke illustrating textural immaturity and compositional maturity. 31 14. Classification of the lower quartzwacke member of the Antelope Mountain Quartzite. 32 Figure Page 15. Middle member quartzwacke in outcrop. 39 16. Iron oxide nodules from siliceous mudstone in middle quartzwacke member. 42 17. Classification of middle quartzwacke member of the Antelope Mountain Quartzite. 44 18. Quartz conglomerate from marker bed in the type locality. 50 19. Classification of slabbed samples collected from conglomerate marker beds in the middle member. 54 20. Sandy conglomerate from the middle quartz- wacke member. 55 21. Pebbly sandstone from the conglomerate marker beds in the middle member. 56 22. Bedded chert member in outcrop. 61 23. Photomicrograph of bedded chert member showing molds of carbonate rhombs, and quartz veins. 63 24. Insoluble residues from sample of bedded chert dissolved in hydrofluoric acid. 65 25. Insoluble residues from sample of bedded chert dissolved in hydrofluoric acid. 66 26. Cretaceous sandstone overlying Antelope Mountain strata. 72 27. Tertiary volcanic rocks in Shasta Valley, north of thesis area. 76 Figure Page 28. Structure of the Antelope Mountain Quartzite. 79 29. Highly fractured chert from bedded chert member near thrust fault on the west side of Antelope Mountain. 81 30. Slab from bedded chert member showing structure of beds. A = tension fractures, B = offset fractures, C = stylolite. 86 31. Zircons from middle member of Antelope Mountain Quartzite. 100 LIST OF TABLES Table Page 1. Modal analysis for Duzel Phyllite. 16 2. Modal analysis for lower quartzwacke member of the Antelope Mountain Quartzite. 30 3. Modal analysis for middle quartzwacke member on Antelope Mountain. 41 4. Modal analysis for the matrix from the conglomerate marker beds in the middle quartzwacke member of the Antelope Mountain Quartzite. 51 5. Modal analysis for framework grains from the conglomerate marker beds in the middle quartzwacke member of the Antelope Mountain Quartzite. 52 LIST OF PLATES Plate Page 1. Geologic map of the Antelope Mountain Quartzite, Yreka, California. in pocket 2. Geologic cross sections of the Antelope Mountain Quartzite, Yreka, California. in pocket 3. Composite stratigraphic section of the Antelope Mountain Quartzite, Yreka, California. in pocket STRATIGRAPHY, STRUCTURE, AND DEPOSITIONAL ENVIRONMENTS OF THE ANTELOPE MOUNTAIN QUARTZITE, YREKA, CALIFORNIA INTRODUCTION Location and Accessibility Antelope Mountain is located in the eastern Klamath Mountains, five miles southeast of Yreka, Siskiyou County, California (Figure 1).The mapped area covers 25 square miles, in parts of 40 sections of Townships 43, 44, 45 North and Ranges 6, 7 West, in the central part of the Yreka Quadrangle. Less than one square mile is under the jurisdiction of the Klamath National Forest, the rest being privately owned.The area is readily accessible from Interstate 5, which runs through the middle of the area, and from U S Highway 99 and the Granada-Montague, Cram Gulch, Guys Gulch, Mill Creek, and Schulmeyer Gulch roads. Numerous private ranch roads and logging roads also extend through the area. Purpose and Methods of Investigation The purpose of this study was to map the stratigraphy and structure of the Antelope Mountain Quartzite, and to determine, if possible, its age and spatial relationship to surrounding rock units. 2 GRENADA I -4 FORT JONES ANTELOPE MOUNTAIN < r-> C.= im -4 GREENVIEW l. cn OUZEL ROCK 4 I n 'II, CON4,NET ROOK GAZELLE 0 Ci )..-4..Y I -4 \..t.A./...,..1 \.1 -4 FT. JONES QUAD. YREKA QUAD. ,...)", 1, f ETNA QUAD. CHINA MTN. QUAD. ' A^ SG ,,_ r- 66 1 V 7 e- lo MAI LEThEAD I MG .,--, ,-y ROCK-- --".