Equivalent Uranium and Selected Minor Elements in Magnetic Concentrates from the Candle Quadrangle, Solomon Quadrangle, and Elsewhere in Alaska GEOLOGICAL SURVEY PROFESSIONAL PAPER 1135 Equivalent Uranium and Selected Minor Elements in Magnetic Concentrates from the 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 medium for geochemical exploration in artic and subartic regions UNITED STATES GOVERNMENT PRINTING OFFICE, WASH INGTON: 1 980 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 1135) Bibliography: p. 103 Supt. of Docs, no.: I 19.16:1135 I. Geochemical prospecting Alaska. 2. Ore-deposits Alaska. I. Pan, Kuo-liang. II. Title: Magnetic concentrates from the Candle quadrangle, Solomon quadrangle, and elsewhere in Alaska. III. 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 Page 1 Distribution of the elements— Continued Introduction--™™-----™™-™--™----™ 2 Candle quadrangle results— Continued 2 51 3 58 3 59 3 Cobalt and nickel —————————————————— 59 3 Indium and thallium ————————————————— 64 xVcLuCLOiuiZcLvion — — —- •— —««—«-•-«— —••«--»--•--«—•-•--•—-••—-«- 3 64 Analytical procedures and reliability of the chemical data — -- 3 65 3 69 16 77 Eight elements by atomic absorption ——— - ——————— 16 7,7 j. GS ts 01 procedure -—™™™——•———••— ——"———«•—— 17 80 Internal replicate analyses in the full data set ———— 18 — 83 19 83 20 Mineralogical composition of magnetic concentrates - 83 20 Magnetite, ilmenite, and rutile —————————— 86 23 Hematite —————————————————————— 86 23 86 23 Quartz and common silicate minerals ——————— 87 Equivalent uranium —— - —— - ——— - ———— - ———— - 25 Other minerals ———— - —— - ——————————— 87 Abundance ——————————— - —— - — - ———— 25 87 30 Mineralogical composition of insoluble residues ——— 89 31 Frequency of association of anomalous amounts of Copper, lead, zinc, and cadmium ———————— - —— 31 elements with specilic minerals *• "~ '-^"~— ——•—-- ..-...« 89 32 Copper, lead, and zinc — - —————————————— 92 33 92 34 92 35 92 TJ*HjaOw o oi*_/»oi"i IsClll/lcLl i* t*o 1 .txlCloJMlA 1 a clr a —-—•----—•--•—--—--••--•---------•--»-—--^^ ^^ 36 Equivalent uranium ——————————————— ™ 94 36 94 36 94 37 95 38 95 W GS t~CGnLrcl.l JrVlflSKfl -•———«———•—•——-•«•——•-«-- 38 Regional- — - —————— • —— - ——————————— 95 39 96 39 97 40 98 40 Copper and silver in southeastern Alaska ————..... 99 40 Multielement highs in southern Alaska — - — - —— 99 42 JDaoc IllcLcilo ill oUULUWt5ol/t?iU /vu&oHa 99 43 West-central -/viasica — ———————•-— ."..»-.« « «T-...^.».. , 99 43 Equivalent uranium in the Bendeleben, Candle, T^ a ct*./»£vn f"t*al Ala olra ««•»-•».»_»_««»_««».»««»«»»- 45 99 45 Lead, cobalt, bismuth, and other elements —— 100 46 100 46 100 46 rvcgiuncii — .— .. — .... .................... ...... .. ...... 100 46 v^andie quadrangle —"-^--- —————— ------- .««--«« ^..T_.™..^..T-™ 102 47 102 40 103 ill IV CONTENTS ILLUSTRATIONS PLATE 1. Map of Alaska showing generalized outlines of areas represented by magnetic fractions of concentrates and topographic quadrangle maps used in this study ———————————— - ————————— -- ———————— In pocket FIGURES 1-10. Concentrations and cumulative frequencies of equivalent uranium and minor elements in Alaskan magnetic concentrates: 1. Equivalent uranium —— - ————————————— - ———————————— - ——————————————————— - 24 3. Lead —————— -- ———— - — - ————— -- ——————————————— - ———— - ————————————————— 26 6. Silver ——— - —— -- ——————————————— - —————————————— -- — -- ——————————————— - — - 27 7. Gold ________ - _ - __ _________ _____ - __________ ______________________ 28 8. Bismuth ———— -- —— - —————————— — ————— - ————— - ——— - ———— - —————————————————— 28 9. Cobalt —— - ———— - —— - —————— - ——————— - —————————— - ———————————————————————— 28 1 1-20. Histograms for equivalent uranium and minor elements in Alaskan magnetic concentrates: J. J.* X-jQUlVcU.Glils UiclIuUIIl ~"""™""*~"~"™"""™"""™"""™~"™~""™~"-~~~"""~"™"'*"~~"~""~"~""™"""""""""'"'~™*""""""~"""*""""™'~'*~"""™""-™""™~"™™"""™"-""""™™*"*""~""""""""™""""""™""™~"™"*" oU 12. Copper ——————— - ——————————— - ——————— -- —— - — - — - ———————— - ——— - ————————— 32 13. Lead-- —— — —————— - ——— - ——————————————— - —————— •• —-————--————--——--—— - 32 1 A. 7iTi/* -* - - QQ 15. Cadmium ————————————— - —————————————————————————— -- ———————————— • — 33 1 6 Silver ____________ ____ • ___________________ ____ - _______________ 3 7 17 Gold __ ___ _______ - ____ - _______ _____ __ - __ - _______________________ 37 18. Bismuth —— - —— - — -- ————— — - ——— - ——————————— - ———— - —— - — - —— - ———————— - —————— 39 19 Cobalt —————— ——————— ——.—..- ................ _ ........... _ .. _ ...... _ ................._ ......... _ ._.._... _ .................... _ ......_...„... 41 20. Nickel ——— - ———— - —— - —— - ——— -- —— - —— - —— - ——————— - — - ———————————— - ————————— 41 21-22. Geologic maps showing the distribution of analyzed magnetic concentrates from the Candle quadrangle, Alaska: 2 1 N^orth wfis tfifn T)d rt —••--••-""•"-*"-" _ - _^ _ , _______ » _ JM _ ..j _ .^-i.— .—-.—-.— .-—n— .•-..».-— -——.-^—..—w— ^— •—«—,—•..- ,.—...-•-.,•—.—. 4ft 22. Southwestern part — - —————————— - —— - —————————— - ———— - —————————————— - —— - — 50 23-30. Maps showing equivalent uranium and minor elements in magnetic concentrates from the Candle quadrangle, Alaska: 23. Equivalent uranium and bismuth, northwestern part — - ——————————— - — -• —— - ————— - —————— 54 A4. ij(JulVcU.Clit UITalUUIu 3.110. DlSIHUl/iXv 25. Copper, lead, zinc, and cadmium, northwestern part - ————— -- —————— - ——— - ————— - ———————— 56 26. Copper, lead, zinc, and cadmium, southwestern part ——————————————— - —————————— - ———— 57 27. Silver, gold, indium, and thallium, northwestern part - ————————————————————— • ———————— 60 28. Silver, gold, indium, and thallium, southwestern part ——————————— - ———— - ———————— - —————— 61 OQ &<•/* 30. Cobalt and nickel, southwestern part — ——— - ————— - —— - — - ——— - ————————— - ——————————— 63 31-32. Geologic maps showing the distribution of analyzed magnetic concentrates from the Solomon quadrangle, Alaska: 31 Northcflstcm D£u*t/ ----------------------------------------------»-------•-----•---------------------«---« fifi 32. East-central part — ———— - —— - —— - ———————————— - ——————————— - ——————————————— 68 33-34. Maps showing equivalent uranium and bismuth in magnetic concentrates from the Solomon quadrangle, Alaska: 33. Northeastern part ——————— - —— - — • ————— - —————————————— - —— - ——————————————— 72 tj*±»Q4 A-JQ-QvT^aof-/»*i«i~ral LrClIU. CLl r\o»«i-VfOLL L ..........—..-. ..... .... ............................................ — — ___„ _«_ ..... .._.. ...•...._....•.... ._ .. ...... ...................... ___ .__._. _. ... .............. ......*.............«...*........._.... ... ..«..__.._..._. .._... ...... .. 7Q| ^ 35. Graph showing relation between equivalent uranium in original heavy-mineral concentrates and equivalent uranium in their magnetic fractions in Alaska -— — — ——————————————————— - —— - ————————————— 74 36-41. Maps showing minor elements in magnetic concentrates from the Solomon quadrangle, Alaska: 36. Copper, lead, zinc, and cadmium, northeastern part ——————————————————— - ———————— - — -• — 75 37. Copper, lead, zinc, and cadmium, east-central part —————————————————————— - — - ———— - —— - 76 38. Silver, gold, indium, and thallium, northeastern part ————————— - —————— -- ———————— - ———— — - 78 39. Silver, gold, indium, and thallium, east-central part —— - —— - —————— - ———— -- ——————— - ——————— 79 4fif\j, PlnKnlfv/lSfcSalU ClllUanr\ niflra]Jlll^AVTl, nr>rfLKJi lilUSdO Vioacforn InSL 11 naffLPdl L ..•-••-••--••-- . _ . ...--..--.«.-..-.. _ ......-...-......—...-..-...-..-...-...-..—......-...-.. ....... .. .. ... .. ... ...... .. ... ......_ .... .„........„......„...._....._ .. .. .. ... ...... ....... ..._ ..... 81O J. 41. Cobalt and nickel, east-central part —— -- —— - —————————————— - —————————— - ————————— 82 CONTENTS V TABLES Page TABLE 1. Locations and results of analyses of 347 magnetic concentrates from Alaska, related to known mineral deposits —— -- — -- — 4 2. Replicate analyses of upsplit and unsized control sample of magnetic concentrates from Hampton Creek placer, Nevada, for Ag, Bi, Cd, Co, Cu, Ni, Pb, and Zn - — - —— ———— - —— - —— -- —— -- — - — —— — ----- — - —— - —— -— -- — .— - 17 3. Replicate analyses of upsplit but sized control sample 300DL of magnetic concentrates from Hampton Creek placer, Nevada, for Ag, Bi, Cd, Co, Cu, Ni, Pb, and Zn — — - — -- —— - —— ~ —— - —— - — - — - — - —— - —— ~ —— ----- —— - — ----- 18 4. Replicate analyses of split but unsized control sample of magnetic concentrate from Lyle Creek, North Carolina, for Ag, 131, V/Q., v/Of l^/Uf INI) L D) £1110. £iH -•-*•-••••-•---•--•••"-"---•--"•--•-------"---------••---------•--"---•••--"••---•--"•------"---•— -•—-•—•—•———•---•— •-"—•—-••--•-•"••• J.O 5. Replicate analyses of split but unsized subsamples of file