Mineralogy and Petrology

, Volume 59, Issue 3–4, pp 143–164

The mineralogy of the Golden Sunlight gold-silver telluride deposit, Whitehall, Montana, U.S.A.

  • P. G. Spry
  • F. Foster
  • J. S. Truckle
  • T. H. Chadwick
Article

Summary

The Golden Sunlight gold-silver telluride deposit, hosted primarily within the Mineral Hill breccia pipe (MHBP), is spatially related to a high-level, Late Cretaceous multiple intrusive, alkaline to subalkaline porphyry system. Base metal veins and manganese (rhodochrosite) mineralization occur up to 2km from the MHBP and form part of a regional mineral zonation pattern genetically related to a low-grade porphyry molybdenum system. Proterozoic rocks of the LaHood Formation and the informally named Bull Mountain Group host the MHBP and contain stratabound sulphides/ sulphosalts (up to 50% pyrite with minor to trace amounts of chalcopyrite, tennantite, pyrrhotite, sphalerite, galena, and molybdenite). Four periods of hypogene mineralization occur in the breccia pipe. Stages I and IV constitute ,≈99% of the mineralization; native gold (4–11 wt.% Ag), calaverite, tetradymite, tellurobismuthite, Se-bearing Bi sulphosalts (aikinite, lindströmite, krupkaite, gladite, bismuthinite, and ?benjaminite), tennantite (Zn, Fe, Te, and Bi varieties), coloradoite, melonite, galena (up to 6.7 wt.% Bi and 6.4 wt.% Se), stannite, chalcocite, and the rare mineral buckhornite are included in stage Ib. Minor amounts of base metals are present in stage II. Gold-silver tellurides (krennerite, petzite, sylvanite, and possibly the rare “x-phase”) developed in stage III whereas barite, fluorite, dolomite, magnesite, trace kaolinite, and sericite formed during stage IV. Utilizing the mineral assemblages in stage Ib, calculated values of logf Te2 and logf S2 range from -10.5 to -9.7, and -12.6 to -5.5, respectively.

Ore forming components (e.g., Au, Ag, Te, Cu, Bi, Mo, and much of the S) were likely derived from the Late Cretaceous intrusive system with possible contributions from the Proterozoic host rocks.

Mineralogie der Golden Sunlight Gold-Silber-Tellurid-Lagerstätte, Whitehall, Montana

Zusammenfassung

Die Golden Sunlight Gold-Silber-Tellurid-Lagerstätte, die hauptsächlich im Brekzienschlot von Mineral Hill (Mineral Hill breccia pipe, MHBP) eingelagert ist, steht räumlich mit einem erzreichen, multi-intrusiven, alkalischen bis sub-alkalischen Porphyritsystem aus der Oberkreide in Beziehung. Erzadern und Mn-Mineralisation (Rhodochrosit) finden sich bis zu 2 km vom MHBP entfernt und sind Bestandteil einer regionalen Vererzung die genetisch zu einem erzarmen Mo-hältigen Porphyritsystem in Beziehung steht. Proterozoische Gesteine aus der LaHood-Formation und der inoffiziell benannten Bull Mountain Group umgeben den MHBP und enthalten schichtgebundene Sulfide und Sulfosalze (bis zu 50% Pyrit mit Neben- bis Spurenmengen von Kupferkies, Tennantit, Pyrrhotin, Zinkblende, Bleiglanz und Molybdänit).[▭

Der Brekzienschlot zeigt vier Phasen hypogener Mineralisation. Stufen I und IV enthalten ≈ 99% der Mineralisation: gediegen Gold (4–11 Gew.% Ag), Calaverit, Tetradymit, Tellurobismuthit, Se-hältige Bi-Sulfosalze (Aikinit, Lindströmit, Krupkait, Gladit, Bismuthinit und ?Benjaminit) Tennantit (Zn-, Fe-, Te- und Bi-Varietäten), Coloradoit, Melonit, Bleiglanz (mit bis zu 6.7 Gew.% Bi und 6.4 Gew.% Se), Zinnstein, Chalcocit, sowie das seltene Mineral Buckhornit treten in Stufe Ib auf. Geringere Mengen von Buntmetallen kommen in Stufe II vor. Gold-Silber-Telluride (Krennerit, Petzit, Sylvanit und möglicherweise die seltene “X-Phase”) sind in Stufe III ausgebildet und in Stufe IV wurden Baryt, Flusspat, Dolomit, Magnesit, Spuren von Kaolin und Serizit gebildet. Unter Verwendung der Mineralassoziationen der Stufe Ib lassen sich Werte von logf Te2 zwischen - 10.5 und - 9.7 und von logf S2 zwischen - 12.6 und - 5.5 errechnen.[▭

Die erzbildenden Komponenten (z.B. Au, Ag, Te, Cu, Bi, Mo und der Grossteil von S) stammen wahrscheinlich vom Intrusivsystem aus der Oberkreide, möglicherweise mit Beiträgen der proterozoischen Umgebung.[/ p]

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References

  1. Afifi AM, Kelly WC, Essene EJ (1988) Phase relations among tellurides, sulfides, and oxides. I. Thermochemical data and calculated equilibria. Econ Geol 83: 377–394Google Scholar
  2. Barton PB Jr, Skinner BJ (1979) Sulfide mineral stabilities. In:Barnes HL (ed) Geochemistry of hydrothermal ore deposits. Wiley-Interscience, New York, pp 278–403Google Scholar
  3. Breskovska V, Tarkian M (1993) Mineralogy and fluid inclusion study of polymetallic veins in the Madjarovo ore field, Eastern Rhodope, Bulgaria. Mineral Petrol 49: 103–118Google Scholar
  4. Cabri LJ (1965) Phase relations in the Au-Ag-Te system and their mineralogical significance. Econ Geol 60: 1569–1606Google Scholar
  5. Chadwick TH (1992) Report to accompany Mineral Hill pit map and sections, 1:1200 scale, including discussions of the geology and gold targets in the pit and elsewhere in the district. Report to Golden Sunlight Mines Inc, 186 p (unpublished)Google Scholar
  6. Charlat M, Lévy C (1974) Substitutions multiples dans la série tennantite-tetraédrite. Bull Soc franç Minéral Crist 97: 241–250Google Scholar
  7. Chekalova KA, Slyusarev AP (1974) Find of seleniferous hammarite in the Orlovskoye deposit, Rudny Altai. Dokl Acad Sci USSR, Earth Sci Sect 216: 144–146Google Scholar
  8. Chen TT, Kirchner E, Paar W (1978) Friedrichite, Cu5Pb5Bi7S18, a new member of the aikinite-bismuthinite series. Can Mineral 16: 127–130Google Scholar
  9. Childs JF, Foster F (dy1993) A geologic summary of significant lode gold systems in Montana. Sc Mining Metall Explor Preprint 93-244, 40 pGoogle Scholar
  10. DeWitt E, Foord EE, Zartman RE, Pearson RC, Foster F (1996) Chronology of Late Cretaceous igneous and hydrothermal events at Golden Sunlight gold-silver breccia pipe, southwestern Montana. US Geol Surv Bull 2155: 48 pGoogle Scholar
  11. Donovan JJ, Rivers ML, Armstrong JT (1992) PRSUPR: Automation and analysis software for wavelength dispersive electron-beam microanalysis on a PC. Am Mineral 77: 444–445Google Scholar
  12. Foord EE, Shawe DR (1989) The Pb-Bi-Ag-Cu-(Hg) chemistry of galena and some associated sulfosalts: a review and some new data from Colorado, California and Pennsylvania. Can Mineral 27: 363–382Google Scholar
  13. ——, ——Conklin NM (1988) Coexisting galena, PbSss and sulfosalts: evidence for multiple episodes of mineralization in the Round Mountain and Manhattan gold districts, Nevada. Can Mineral 26: 355–376Google Scholar
  14. Foster F, Chadwick TH (dy1990) Relationship of the Golden Sunlight mine to the Great Falls Tectonic Zone. In:Moye FJ (ed) Geology and ore deposits of the Trans-Challis Fault System/Great Falls Tectonic Zone. Tobacco Root Geological Soc 15th Ann Field Trip Guide, pp 77–81Google Scholar
  15. — (1997) Some observations regarding formation correlations and regional paleogeography of the southern Helena Embayment. Montana Bureau of Mines Spec Pub (in press)Google Scholar
  16. Nilsen TH (1997) Paleodepositional setting and synsedimentary mineralization in Belt Supergroup rocks of the Whitehall, Montana area. Montana Bureau of Mines Spec Pub (in press)Google Scholar
  17. Foster F, Childs JF (1993) An overview of significant lode gold systems in Montana, and their regional geological setting. Explor Mining Geol 2: 217–244Google Scholar
  18. Francis CA, Criddle AJ, Stanley CJ, Lange DE, Shieh S, Francis JG (1992) Buckhornite, AuPb2BiTe2S3, a new mineral species from Boulder County, Colorado, and new data for aikinite, tetradymite and calaverite. Can Mineral 30: 1039–1048Google Scholar
  19. Herbert HK, Mumme WG (dy1981) Unsubstituted benjaminite from the AW Mine, NSW: a discussion of metal substitutions and stability. N Jahrb Mineral Monatsh: 69–80Google Scholar
  20. Johan Z, Dódony I, Morávek P, Pašava J (1994) La buckhornite, Pb2AuBiTe2S3, du gisement d'or de Jilove, Republique tcheque. CR Acad Sci Paris 318 (série II): 1225–1231 (in French)Google Scholar
  21. Johnson NE, Craig JR, Rimstidt JD (1986) Compositional trends in tetrahedrite. Can Mineral 24: 385–397Google Scholar
  22. Kesler SE (1981) Mineralogical study of three pyrite concentrates (F-501, F-502, F-503) from Mineral Hill gold deposit, Montana. Report to Placer Dome, 53 p (unpublished)Google Scholar
  23. Kiukkola K, Wagner C (1957) Measurements of galvanic cells involving solid electrolytes. Electrochem Soc 104: 379–386Google Scholar
  24. Knittel U (1989) Composition and association of arsenian goldfieldite from the Marian gold deposit, northern Luzon, Philippines. Mineral Petrol 40: 145–154Google Scholar
  25. Kostov I, Minčeva-Stefanova J (1982) Sulphide minerals - crystal chemistry, parageneses and systematics. Schweizerbart'sche Verlagsbuchandlung, StuttgartGoogle Scholar
  26. Kovalenker VA, Malov VS, Yevstigneeva TL, Vyal'sov LN (1984) Junoite and pekoite - first find in the USSR. Zap Vses Mineral Obshch 113: 35–43Google Scholar
  27. Kovalenker VA, Zalibekyan MA, Laputina IP, Malov VS, Sandomirskaya SM, Gras'ko MI, Mkhitaryan DV (1990) Sulfide-telluride mineralization of the Megradzor ore field, Armenia. Int Geol Rev 32: 705–720Google Scholar
  28. Legendre B, Souleau C, Hancheng C (1980) Le systém ternaire or-argent-tellure. Soc Chim Française Bull 1: 197–204Google Scholar
  29. Lindquist AE (1966) Structure and mineralization of the Whitehall mining district, Jefferson County, Montana. Thesis, Montana TechGoogle Scholar
  30. Lowry D, Stephens WE, Herd DA, Stanley CJ (1994) Bismuth sulphosalts within quartz veining hosted by the Loch Shin monzogranite, Scotland. Min Mag 58: 39–47Google Scholar
  31. Malakhov AA (1968) Bismuth and antimony in galenas as indicators of some conditions of ore formation. Geochim Int 5: 1055–1068Google Scholar
  32. Mills KC (1974) Thermodynamic data for inorganic sulfides, selenides, and tellurides. Butterworths, LondonGoogle Scholar
  33. Mozgova NN, Tsepin AI (1983) Fahlores (Peculiarity of the chemical compositions and properties). Nauka, Moscow, 280 p (in Russian)Google Scholar
  34. Mumme WG, Watts JA (1976) Pekoite, CuPbBi11S18, a new member of the bismuthiniteaikinite mineral series: its crystal structure and relationship with naturally- and synthetically- formed members. Can Mineral 14: 322–333Google Scholar
  35. Paredes MM 1994 A fluid inclusion, stable isotope, and multi-element study of the Golden Sunlight deposit, Montana. Thesis, Iowa State UniversityGoogle Scholar
  36. Päsava J, Breiter K, Malátek J. Rajlich P (1986) Cu-rich rucklidgeite and an unnamed PbAu-Bi sulphotelluride from the Jílové gold deposit. Věst Ústř ÚTavu Geol 61: 217–221 (in Czech)Google Scholar
  37. Pouchou JL, Pichoir F (1985) “PAP” (phi-rho-Z) procedure for improved quantitative microanalysis. In:Armstrong (ed) Microbeam analysis. San Francisco Press, San Francisco, pp 104–106Google Scholar
  38. Porter EW, Ripley E (1985) Petrologic and stable isotope study of the gold-bearing breccia pipe at the Golden Sunlight deposit, Montana. Econ Geol 80: 1689–1706Google Scholar
  39. Pring A (1989) Structural disorder in aikinite and krupkaite. Am Mineral 74: 250–255Google Scholar
  40. Rice CM, Harmon RS, Shepherd TJ (1985) Central City, Colorado: the upper part of an alkaline porphyry molybdenum system. Econ Geol 80: 1769–1796Google Scholar
  41. Rucklidge J, Stumpfl EF (1968) Changes in the composition of petzite (Ag3AuTe2) during analysis by electron microprobe. N Jahrb Mineral Monatsh: 61–68Google Scholar
  42. Spry PG, Thieben SE (1996) Epithermal gold-silver telluride deposits of Montana: mineralogical characteristics. Geol Soc Am Abst Progr 28–34: 39Google Scholar
  43. Spry PG, Parades MM, Foster F, Truckle J, Chadwick TH (1996) Evidence for a genetic link between gold-silver telluride and porphyry molybdenum mineralization at the Golden Sunlight deposit, Whitehall, Montana: fluid inclusion and stable isotope studies. Econ Geol 91: 507–526Google Scholar
  44. Thieben SE, Spry PG (1995) The geology and geochemistry of Cretaceous-Tertiary alkaline rock-related gold-silver telluride deposits of Montana, USA. In:Pašava J, Kříbek B, Žäk K (eds) Mineral deposits: from their origin to their environmental impacts. A.A. Balkema, Rotterdam Brookfield, pp 199–202Google Scholar
  45. Wuensch BJ (1964) The crystal structure of tetrahedrite, Cu12Sb4S13. Z Krist 119: 437–453Google Scholar

Copyright information

© Springer-Verlag 1997

Authors and Affiliations

  • P. G. Spry
    • 1
  • F. Foster
    • 2
  • J. S. Truckle
    • 2
  • T. H. Chadwick
    • 3
  1. 1.Department of Geological and Atmospheric SciencesIowa State UniversityAmesUSA
  2. 2.Golden Sunlight Mines, Inc.WhitehallUSA
  3. 3.BelgradeUSA

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