STUDIES RELATED TO WILDERNESS MINE,RAL. RESOURCES YOF· THE STRAWBERRY.· MOUNTAIN WILDERNESS AND ADJACENT AREAS, GRANT COUNTY, OREGON Mineral Resources of the ' Strawberry Mountain Wilderness and Adjacent Areas, Grant County, Oregon By THOMAS P. THAYER and JAMES E. CASE, U.S. GEOLOGICAL SURVEY and by RONALD B. STOTELMEYER, U.S. BUREAU OF MINES STUDIES RELATED TO WILDERNESS-WILDERNESS AREA~ GEOLOGICAL SURVEY BULLETIN 1 4 9 8 An evaluation of the mineral potential of the area UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1981 UNITED STATES DEPARTMENT OF THE INTERIOR JAMES G. WATT, Secretary GEOLOGICAL SURVEY Doyle G. Frederick, Acting Directo1· Library of Congress Cataloging in Publication Data Thayer, Thomas Prence, 1907- Mineral resources of the Strawberry Mountain Wilderness and adjacent areas, Grant County, Oregon. (Studies related to wilderness-wilderness areas) (Geological Survey bulletin; 1498) Bibliography: p. Supt. of Docs. no.: I 19.3:1498 1. Mines and mineral resources-Oregon-Grant Co. I. Case, James E., 1933- joint author. II. Stotelmeyer, Ronald B., joint author. III. Title. IV. Series. V. Series: United States. Geolog­ ical Survey. Bulletin; 1498. QE75.B9 no. 1498 [TN24.07] 557.3s 553'.09795'78 80-607903 For sale by Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 STUDIES RELATED TO WILDERNESS In accordance with the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Joint Conference Report on Senate Bill 4, 88th Congress, the U.S. Geological Survey and U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Studies and reports of all primitive areas have been completed. Areas officially designated as "wilder­ ness," "wild," or "canoe" when the act was passed were incorpo­ rated into the National Wilderness Preservation System, and some of them are currently being studied. The act provided that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. This report discusses the results of a mineral survey of some national forest lands in the Strawberry Mountain Wilderness and adjacent areas that are being considered for addition to the Wil­ derness in Grant County, Oregon. CONTENTS Page Summary ___ -: _____________________________________________________________ _ Introduction ______________ -.-________________________________________________ 4 Geology and mineral resources, by Thomas P. Thayer----------------------------- 6 Previous studies________________________________________________________ 6 Present investigation and acknowledgments__________________________________ 6 Geology -------------------------------------------------------------- 7 Setting ---------------------------------------------------------- 7 ·canyon Mountain Complex_________________________________________ 7 Peridotite and gabbro __ ___ _ __ _ _ _ __ _ _ _ _ __ _ ___ _ __ _ __ _ _ _ ___ __ _ ___ 8 Rocks of the sheeted dike unit---------------------------------- 8 Structure____________________________________________________ 11 Tertiary volcanic rocks ______________________________ ------_ _ _ ___ _ __ 12 Clarno Formation _ _ __ _ ___ _ _ _ _ _ _ _ _ _ __ _ __ _ ___ ___ ___ _ __ __ _ ___ __ _ 12 Strawberry Volcanics__________________________________________ 13 Structure____________________________________________________ 14 Surficial deposits__________________________________________________ 15 Mineral deposits _ _ __ _ _ _ _ _ _ _ _ _ __ _ __ _ ___ ___ _ __ _ __ _ _ _ __ _ __ _ ___ ___ _ __ _ _ _ ___ 16 Chromium, nickel, and platinum-group metals__________________________ 16 Copper------------------------------------~--------------------- 17 Gold____________________________________________________________ 18 MercurY--------------------------------------------------------- 19 Magnesite________________________________________________________ 19 Geothermal energy resources _ _ _ _ __ _ ___ ___ _ __ _ __ _ __ __ _ ___ _ __ __ _ ___ _ __ 19 Geochemical investigations _ _ _ _ _ __ _ ___ ___ _ __ _ __ _ _ _ __ _ ___ __ _ ___ _ _ _ _ __ ___ _ _ _ 20 Geochemical patterns _ __ _ ___ ___ _ __ _ _ _ ___ ___ ___ ___ ___ _ _ _ __ _ ___ _ __ __ _ 22 Gold, silver, and platinum metals ------------------------------------ 23 Copper, lead, and zinc __ _ _ _ _ ___ ___ ___ ___ _ __ _ _ _ _ _ _ ___ ______ _ _ _ __ _ ___ 34 Conclusions __ _ _ _ _ _ _ __ _ ___ __ _ ___ ___ _ __ _ __ _ __ _ _ _ _ _ _ __ _ ___ ___ ___ _ _ _ ___ ___ 34 Geologic interpretation of aeromagnetic map, by James E. Case and Thomas P. Thayer _______________________ --:____________________________ 35 Anomalies over the Canyon Mountain Complex ----------------------------- 36 Anomalies over Strawberry Volcanics-------------------------------------- 39 Steepened gradients ______________________________ .:.______________________ 40 Conclusions _ _ ___ ___ _ __ _ _ _ __ _ ___ ___ ___ ___ ___ _ __ _ _ _ __ _ __ _ ___ _ __ _ __ ___ ___ 40 Acknowledgments ___ _ _ _ _ _ _ __ _ ___ ___ ____ __ _ _ _ _ _ _ _ _ _ __ _ __ _ ___ __ _ _ __ ___ ___ 40 Economic appraisal, by Ronald B. Stotelmeyer____________________________________ 40 Setting --------------------------------------~------------------------ 40 Previous work--------------------------------------------------------- 43 Present investigations ___ _ _ _ _ __ _ _ _ ___ ___ ___ ___ ___ __ _ ______ ___ _ __ _ _ _ ______ 43 Mining claims ________________________________________ _:_ ___ ___ ___ ___ ___ 44 Methods of study_______________________________________________________ 44 Sampling and analytical methods__________________________________________ 45 Mineral commodities and economic considerations____________________________ 46 Chromium ________________________________________________ ·_ _ __ __ _ 46 IX X CONTENTS Page Economic appraisal-Continued Mineral commodities and economic considerations-Continued Copper __________________________________________________________ _ 46 Mercury --------------------------------------------------------- 47 Mines and prospects ____________________________________________________ _ 47 Chromite deposits ______________________________ L _________________ _ 47 Celebration mine ____________________________________________ _ 48 49 51 ~~<~~;);~~~~::~~:~~~;:::::::::::::::::!::::::::::::::::::: 51 Black Rock claim _________________________ _,_ __________________ _ 52 Snow Drift claim _________________________ _,_ __________________ _ 53 Copper occurrences _____________________________ _,_ __________________ _ 53 Robert L. claim group ________________________________________ _ 53 Norton Fork copper occurrences--------------------------------- 56 Blue Rock claim _____________________________________________ _ 57 Mercury deposit _______________________________ ~ __________________ _ 58 Platinum-palladium, nickel, and magnesite occurrences, __________________ _ 60 Geothermal resources ___________________________ .: __________________ _ 64 Miscellaneous prospects _________________________ ~-- ________________ _ 64 References cited ____________________________________________________________ _ 66 ILLUSTRATIONS Page FRONTISPIECE. View south and west from Baldy Mountain. PLATE 1. Maps showing geology, aeromagnetic survey, ~mall stream ba­ sins, locations of geochemical samples, and kinds of rocks sampled, Strawberry Mountain WilderneJs and adjoining areas------------------------------~------------- In pocket FIGURE 1. Map of the Strawberry Mountain Wilderness study area show- ing potential chromium and copper resour~e localities ___ _ 2 2. Map showing location of the Strawberry Mou~tain Wilderness ~udy area--------------------------~~------------ 4 3-5. Photographs showing: 3. Sheep Rocks, showing rugged exposures of gabbro _____________________ , ____________ _ 5 4. Alternating dikes of albite granite and basalt or di­ abase in the sheeted dike unit, n~ar the head of Tamarack Creek _____________ -1- ___________ _ 9 5. View east along the cirque wall at th~ head of Straw- berry Creek valley ___________ -[- ___________ _ 14 6. Magnetic profiles along section A-A' of plate 1B, and geologic interpretation of the aeromagnetic anomaly over the Canyon 1 Mountain Complex ___________________ ____________ _ 37 7. Map showing mines and prospects, Straw~erry Mountain Wilderness and vicinity ________________ I____________ _ 42 CONTENTS XI Page FIGURE 8. Plan and section of the Celebration chromite mine _______ _ 49 9-13. Plans of: 9. Ray (Tip Top) chromite mine----------------- 50 10. Robert L. copper prospect -------------------- 54 11. Ad it at the Blue Rock copper prospect _________ _ 58 12. Surface workings, Canyon Creek mercury mine ___________________________________ _ 60 13. Underground workings, Canyon Creek mercury mine------------------------------------ 61 TABLES Page TABLES 1-5. Data from the Strawberry Mountain Wilderness and adjoining areas: 1. Summary of analyses for selected metals in samples__________________________________ 21 2. Analyses of vein and altered rocks______________ 22 3. Semiquantitative spectrographic analyses of panned concentrates _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 24 4. Semiquantitative spectrographic analyses of stream- sediment samples and rocks ----------------- 26 5. Summary of data on miscellaneous prospects_________________________________ 64 STUDIES RELATED TO WILDERNESS-WILDERNESS AREAS MINERAL RESOURCES OF THE STRAWBERRY