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Geology of the Eastern Part Beaty Butte Four Quadrangle, Oregon

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Geology of the Eastern Part Beaty Butte Four Quadrangle, Oregon G r OF THE EASTERN PART BEATY BUTTE FOUR QUADRANGLE, OR S ON by Neil Joseph Maloney A THESIS submitted to OR ON STATE COLLEGE in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE June 1961 APPROVED: Redacted for Privacy Instructor of Geology in Charge of Major Redacted for Privacy Chairman of Department of Geology Redacted for Privacy Chairman of School Graduate Committee Redacted for Privacy. Dean of Graduate School Date thesis is presented 3 /910 Typed by Verna Blaine ACIC to 3 I am very grateful to Mr. D. O. Cochran who supervised and assisted the work in a great many ways. I am grateful to Drs. I. S. Allison and D. A. Bostwick for critically reviewing the manuscript. I would like to thank all of the faculty for advice and suggestions con. corning the thesis, especially Dr. Bostwick for aid in preparation of the plates, Dr. J. C. Cummings for sugges- tions concerning structural geology, and Mr. J. R. Snook for the axial angle of the anorthoolase. I gratefully acknowledge the many conversations and patient good humor of Daniel Johnson and Prank Blair who were co-workers in the field. TABLE OF CONTENTS NTRODUCTION . Page 1 Location and Accessibility......... .... .. ... 1 Previous Work 1 Present Worki14101100.00041 . *di . 0000**080090000041 3 Geography.. .... ... ... ***** . * . ***** ....... 4 STRATIGRAPHY." ............... ***** 5 Regional Stratigraphy 5 Local Stratigraphy ... 7 Steens Basalt....... "4'. ** 7 Lithology......,... ** . * ............ 10 Origin................... 13 Lone Mountain Formation.......... * ... 13 Lithology-Vitrophyres .... 16 Lithology-Felsites"a.... ... 19 Origin ... ***** ......" .0.. 23 Danforth CO Formation.. 25 Lithology......... * .... ... a ... ... 26 Origin................ .... ......... 27 Thousand Creek 01 Formation.... 27 Lithology... .. ** ....... ** . ** 41,01,0110 28 Origin ** . * * . * , * ,......., 30 Older Alluvium....... **** * 30 Mesa Basalt * . **** .............. *** ** 4,0 32 Lithology........ .... 34 Origin ..... .... ..... ** 35 ernary Alluvium 36 PHYS OGRAPHY............ 39 Hollyhock Area............... ........... 39 Hollyhock High Plain.......... * .. ** . * . ** 40 Actey Piedmont . 41 Remnant Hill ...... **** . * .., 41 Lone Mountain Area .. **** 0011.0000000004, 42 Basco Hills ...... 42 Funnel Canyon . ..... ****** .... 43 Lone Mountain ............** . ****** ...... 45 Hawks Valley Area .... ** . ** .. * . * ... 45 Actey -Hawks Mountain Area . ... 47 Actey Mountain ..... ... 47 West Hawksiewalksie Fault Blocks........ 48 Hawks Mountain .... * .. 49 Hawksiewalksie Area......... ......... 49 Hawksiewalksie Playa.... 49 Southern Lowlands................ OOO . O Mesa Basalt High Plain 50 GEOLOGIC STRUCTURE 51 Regional Structure 51 Summary 53 Faults............... O . O ........ 53 North-Striking Faults.......... 59 Northeast-Striking Faults............. 60 Northwest-Striking Faults OO O 62 Fault Types ............ OOOOOOOO ....... 614. Folds ........... 64 Sequence of Deformation OOO ........... 67 Summary..ros. OO 41. OOOO ................. 67 Lone Mountain Area O 67 Actey -Hawks Mountain Area ............. 73 Mechanics of Deformation .................. 75 Discussion .............. 75 First Stage of Deformation ............ 78 Second Stage of Deformation ........... 79 Third Stage of Deformation 81 GEOLOGIC HISTORY ............... OOOO . OO ........ 83 BIBLIOGRAPHY m** OOOOOOOOO OO 0* OO . 85 LLU TTIONS List of e Picture Page 1, Massive black Steens basalt ,......... 11 2. Outcrop of concordantvitrophyre at Juniper Springs 15 Outcrop of concordantvitrophyre at Basco Horst 15 Hoodoo in Lone Mountain felsite ... 17 Outcrop of vesicular felsite 41741,41.110,041,40.0 17 6. Outcrop of Thousand Creek (?) tuff .... 29 7. Outcrop of Older Alluvium grave] ...... 31 8 Lone Mountain Mesa basalt contact at Remnant Hill 31 9 Small playa at Lone Mountain 41 .............41. 46 10, View of Hawksiewalksie Playa from Hawks Mountain....... ... .. .... .. 46 11. View of P.22 scarp from Juniper Spring 58 12, Small graben between Hawks and Actey Mountains 58 13. View of Basco Horst from Actey Piedmont 61 14. View of Hawks Mountain from Juniper Spring.. 61 List of Tables Table I Summary of exposed formations 9 List of Plates Plat. Page Index map showinglocation of the eastern part, Beaty ButteFour quadrangle, Oregon 2 Correlation chartOoltO41410,41 OOOOOO 00004,01,Wei 8 3. Maximum extent of Mesa basalt in the thesis area OOOOOOO OOOO ......... ***** 33 4. Physiographic map of the thesis area * *** 38 5. Distribution map of faults in the thesis area. 54 6. Distribution map of the north - striking fault system in the thesis area 55 7. Distribution map of the northeast - striking fault system in the thesis area ********* 56 8. Distribution map of the northwest striking fault system in the thesis area.... .... 57 9. Sketch maps showing fold -fault relations 65 10. Fault relations in vicinity of Funnel Canyon 69 11. Fault relations in vicinity of Lone Mountain 70 12. Fault relations on the Actey.liamk Mountain range .......... OOOOOOO 74. 13. Stress -fault orientations and relations ...... 76 14. A. Idealized fracture pattern relations 80 B. Approximate orientation of the horizontal principal stress axes for the three stages of deformation ....... ******** 80 15. Geologic map of the eastern part Beaty Butte Four quadrangle, Oregon ***** ............. 88 GEOLOGY OF THE EASTERN PART BEATY BUTTE FOUR QUADRANGLE, OREGON INTRODUCTION Location,a,,nd Accessibility The Beaty Butte Four Quadrangle is located in the southernmost part of Harney County, Oregon.The thesis area includes about 130 square miles which lie between 420 00' and 112° 15 north latitude and 119° 00' and 119° 08' west longitude. (Plate 1) Burns is 95 miles north, Lakeview 100 miles west and Denio 40 miles east. Access to the area during dry weather may be gained by traveling north on dirt roads which join Nevada State Highway 8A at Thousand Creek Ranch and Big Springs, and by traveling south on a dirt road that joins the Frenchgleu-Fields road at the base of Catlow Rim. Previous Work This thesis is the first recorded geologic inveatiga. Lion of the eastern part of the Beaty Butte Pour Quadrangle. However, considerable geologic work has been done in nearby areas. Blake (5), I. C. Russell (24), and Waring (30, 31) 124° 12 3° 122° 121° 120° 118° 117° 46° Portland 45° Corvallis 0 REGON 44P )1(< Eugene Burns HARNEY COUNTY Lakeview Denio I 1 I PlateI.Index map showing location of the easternpart,Beaty Butte Four Quadrangle, Oregon. have made reconnaissance studies in southeastern Oregon. Merriam (17) described the mammalian fossils andatm.. tigraphy at Thousand Creek and Virgin Valley, Nevada. Fuller (11) described the stratigraphiosequence at Steens Mountain, and Piper, Robinson and Park (21) mappedand re- corded the stratigraphio sequence in the Harney Basin. Cochran (7) is currently workingon the structure and stratigraphy of the Pueblo Mountains. Johnson (13) and Blair (4) mapped areas adjacent to the east side of the thesis area. Other workers in the region are listed in the bibliography. Present Itris. This report is based upon field work done during 11 weeks between June 15 and September 17, 1958, and labors.. tory work done during the spring and summer of 1959. Geology was plotted on areal photographs at a scale of 1:30,000, and then transposed to the Beaty Butte Four planimetric quadrangle map enlarged toa scale of 1:31,680. Fault-strike frequencies were determined by using the bearings of the fault traces as plotted on the basemap. Inaccuracies are introduced by the lack of topographic control. However, the steepness of the faults and a general low relief along the fault traces minimize the inaccuracies. 4 The faults have been numbered for convenienceof ref. 'reflect. The numbering system is illustrated in Plates 10, 11, and 12, pages 69, 70 and 74. Geography Locations of the major physiographic areas are shown in Plate 4.. (Page 38) wks Mountain, 7,200 feet in slava. tion, is the highest peak in the thesis area. The lowest point is at the intersection of Funnel Canyon and the east ern boundary of the area where the elevation is about 5,000 feet. This gives a maximum relief of about 2,200 feet. ological data is available.However, the imate tract ri ed by little precipitation and large seasonal and daily temperature ranges. Summers are hot th occasional thundershowers; winters are cold and windy with some snow. Vegetation oonsiata mainly of short grass, sagebrush and widely scattered juniper trees.The grass is used for cattle and sheep grazing. 5 STRAPIG A atigraRhy The ages and etratigraphio positions of the mapped units are known mainly from stratigraphio relationsand fossils described in adjacent areas.The following para. graphs present a summary of this evidence. A small flora has been found in the Alvord Creek fr mations which includes the earliest Tertiary rocks exposed on the east face of the Steens Mountains. Chaney (11, p. 114) dated the flora as Middleor Upper Miocene. Later, Axelrod (2, p. 247) dated the same floraas Lower Pliocene, and Wolf (10) dated another collection from the same locality as Middle Pliocene. The Steens basalt is stratigraphically above and therefore younger than the Alvord Creek formation on Steens Mountain. No fossils have been described from the Steens basalt. Fossil vertebrates were found in tuffs immediately overlying the Steens basalt at Beaty Butte. Wallace (30, p. 117) dated the fauna as MiddleMiocene. Merriam (16, p. 199-304) described Middle or Upper Miocene
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