@'&% ' ' P- "4~op Equivalent Uranium and 153 - Q&* $,$d4v 3 Selected Minor Elements in "%~G,-'Q@ca~t %d44 Magnetic Concentrates from the s~$qd-e Candle Quadrangle, Solomon Quadrangle, and Elsewhere in Alaska By KUO-LIANG PAN, WILLIAM C. OVERSTREET, KEITH ROBINSON, ARTHUR E. HUBERT, and GEORGE L. CRENSHAW GEOLOGICAL SURVEY PROFESSIONAL PAPER 1135 An evaluation of magnetic concentrates as a mediumfor geochemical exploration in artic and subartic regions UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON:1980 UNITED STATES DEPARTMENT OF THE INTERIOR CECIL D. ANDRUS, Secretary GEOLOGICAL SURVEY H. William Menard, Director Library of Congress Cataloging in Publication Data Main entry under title: Equivalent uranium and selected minor elements in magnetic concentrates from the Candle quadrangle, Solomon quadrangle, and elsewhere in Alaska. (Geological Survey Professional Paper 1 135) Bibliography: p. 103 Supt. of DOCS.no.: I 19.16:1135 1. Geochemical prospecting-Alaska. 2. Ore-deposits-Alaska. I. Pan, Kuo-liang. 11. Title: Magnetic concentrates from the Candle quadrangle, Sofomon quadrangle, and elsewhere in Alaska. 111. Series: United States Geological Survey Professional Paper 1135. TN270.E78 622'.13'09798 79-607131 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS page Abstract --------------------------------------------------1 Distribution of the elements-Continued Introduction ----- ----------------------------- -------------- 2 Candle quadrangle results-Continued Purpose of investigation ------------------------------ ----- 2 Copper, lead, zinc, and cadmium ------------ Acknowledgments ---------------- ------ 3 Silver and gold ---------------------- ----------- Magnetic fractions of concentrates -- 3 Bismuth --------------------- Source and preparation -------- --- 3 Cobalt and nickel ------------------ Location and distribution- -------------------- ------- 3 Indium and thallium --------------------------- Randomization --------------------------------------------------3 Solomon quadrangle results ----------------------------- Analytical procedures and reliability of the chemical data ----- 3 Equi?ralent uranium --------------------------------- Control samples --------------------------------------------------3 Copper, lead, zinc, and cadmium --------------------- Equivalent uranium --------------------------------------------------16 Silver and gold ----------------------------------------- Eight elements by atomic absorption -------------------------16 Bismuth ------------------------------------- Tests of procedure ------------------------ 17 Cobalt and nickel --------------------- ------- Internal replicate analyses in the full data set ---------18 Indium and thallium ---------------------------- Gold, indium, and thallium by atomic absorption ---------19 Sources of the anomalous elements -------------------------- Distribution of the elements -----------------------------------20 Mineralogical composition of magnetic concentrates ----- Background review ------------------------------------------- 20 Magnetite, ilmenite, and rutfie ---------------------- Regional results ------------------------------------------------ 23 Hematite ------------------------------------------------ Areas discussed ------------------------------------------- - 23 Sulfide minerah and gold -------------------------------- Statistical treatment -------------------------------------------- 23 Quartz and common silicate minerals ----------------- Equivalent uranium -----------------------------------------------25 Other minerals ---------------------------------------------- Abundance ----------------------------------------------------- 25 Metallic spherules and tramp iron --------------------- Mineralogical sources ---------------------------*----- 30 Mineralogical composition of insoluble residues ----------- Possible use --------------------------------------------- -- 31 Frequency of association of anomalous amounts of Copper, lead, zinc, and cadmium ------------------------31 elements with specific minerah -------------- -------------- Southeastern Alaska ----------------------------------- 32 Copper, lead, and zinc --------------------------------- Southern Alaska ------------------------------------- ------- 33 Silver --------------------------------------------------------- Southwesten Alaska ---------------------------------------- 34 Bismuth and cadmium -------------------------------------- West-central Alaska -------------------------.---------------35 Cobalt and nickel -------------------------------------------- East-central Alaska 36 Equivalent uranium ------------------------------------ Silver and gold -----------------------------------------36 Gold, indium, and thallium ----------------------------- Southeastern Alaska ----------------- 36 Role of anomalous environments ----------------------------- Southem Alaska -------- ------ 37 Relations among the elements --------------------------------- Southwestern Alaska --------- 38 Correlations ---------------------------------------------------- West-central Alaska ---------------------- 38 Regional -------------------------------------------------- East-central Alaska ------------------------------------- 39 Candle quadrangle ------------------------------------------ Bismuth ----------------------------------------------------------39 Solomon quadrangle -------------------------------------- West-central Alaska ----------------------------------40 Prominent geochemical highs ------------------------------------- East-central Alaska ------------------ 40 Copper and silver in southeastern Alaska ------------ Cobalt and nickel ------------------ 40 Multielement highs in southern Alaska ---------- Southern Alaska - 42 Base metals in southwestern Alaska ---------------- Southwestern Alaska --- 43 West-central Alaska -- -------------- West-central Alaska --------------- 43 Equivalent uranium in the Bendeleben, Candle, East-central Alaska -------------------------- 45 and Solomon quadrangles ------------------- Indium and thallium --------------------------- 45 Lead, cobalt, bismuth, and other elements Southern Alaska ---------------------- 46 Silver and gold in east-central Alaska ------------------- Southwestern Alaska -------------- 46 Geologic and,geochemical interpretation------------------------------ West-central Alaska ----------- 46 Regional ---------- ---------------------------------- East-central Alaska 46 Candle quadrangle Candle quadrangle results .............................................. 47 Solomon quadrangle --------- --------------------------------------- Equivalent uranium ..................................................... 49 Selected references ------------------------------------------------- CONTENTS ILLUSTRATIONS page PLATE1. Map of Alaska showing generalized outlines of areas represented by magnetic fractions of concentrates and topographic quadrangle maps used in this study ---------------------------------------- -------------------------------------- In pc wket Concentrations and cumulative frequencies of equivalent uranium and minor elements in Alaskan magnetic concentrates: 1. Equivalent uranium ------------ --------------------------------.------------------------------------------- 2. Copper ------------------------------------------------------------------------------------------------------------------------ 5. Cadmium -- 6. Silver ----------------------------------------------------------------- ----------------------------- 7. Gold -------------------------------------------------------------------------------------------------------------------------------------- 8. Bismuth ---------------------------------------------------------------------------------------------------------------------------------------------- 9. Cobalt -----------------------------------.------------------------------- -------------------------------- .-------------------------------------------------- 10. Nickel - ------------------------.------------------------------------------------------------------------------- Histograms for equivalent uranium and minor elements in Alaskan magnetic concentrates: 11. Equivalent uranium -----.---------------------------------------------------- --------------- 12. Copper ---------------------------------------------------------------- -------------------------------------------------------------- 13. Lead -- ---. 14. Zinc ---------------------------------------- . - 17. Gold ---------------------------------------------------------------------------------------------------------.----------------------------- 18. Bismuth ----------------------------------------- 19. Cobalt ----------------------------------------------- 20. Nickel -------------------------------------------------------------------------------------------------------------------------------------- Geologic maps showing the distribution of analyzed magnetic concentrates from the Candle quadrangle, Alaska: 21. Northwestem part ------------------------------------------------------------------------------------------------------------------------------------ 22. Southwestern ~art--------------------------------------------------------------------------------------------------------------------------------- Maps showing equivalent uranium and minor elements in magnetic concentrates from the Candle quadrangle, Alaska: 23. Equivalent uranium and bismuth, northwestern part ----------------------------------.----------