Abstract
Sulfide minerals in the Boulder batholith occur 1. as disseminated grains, visible in hand specimens; 2. in aplitic-pegmatitic pods and masses; 3. along joint and shear surfaces; 4. in hydrothermal veins; and 5. as minute masses within pyrite and silicate minerals and along intergranular sites. Hydrothermally altered rocks have an average sulfide content of 0.8 weight per cent, compared to an average of 0.01 per cent for unaltered rocks. Unaltered rock of the batholith may contain as much as 0.7 weight per cent sulfide. Sulfide inclusions in pyrite, the most abundant sulfide of the batholith, are common and represent a captured iss-phase which later changed to chalcopyrite plus pyrrhotite or mackinawite. Inclusions are most abundant, and more complex, in pyrites of hydrothermally altered and ore rocks. Electron-probe analyses show that pyrites of the Boulder batholith have very similar compositions to those found for pyrites from other ore deposits around the world.
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Al-Hashimi, A. R., Brownlow, A. H.: Copper content of biotites of the Boulder batholith, Montana. Econ. Geol. 65, 985–992 (1970)
Brimhall, G. H., Jr.: Mineralogy, texture, and chemistry of early wall rock alteration in the deep underground mines and continental area, Butte district, Montana. In (R. N. Miller, Ed.) Guidebook for the Butte Field Meeting of Society of Economic Geologists, H-1 to H-5 (1973)
—: Early fracture-controlled disseminated mineralization at Butte, Montana. Econ. Geol. 72, 37–59 (1977)
Burns, R. G.: Mineralogical Application of Crystal Field Theory, 224 pages. New York: Cambridge University Press, 1970
Cabri, L. J.: New data on phase relations in the Cu-Fe-S system. Econ. Geol. 68, 443–454 (1973)
Chakrabarti, A. K.: On the trace element geochemistry of Zawar sulphides and its relation to metallogenesis. Can. Mineral. 9, 258–262 (1967)
Deer, W. A., Howie, R. A., Zussman, J.: Rock-forming Silicates, 371 pages. London: V. Longmans 1962
Desborough, G. A.: Magmatic sphalerite in Missouri basic rocks. Econ. Geol. 58, 971–977 (1963)
Desborough, G. A., Anderson, A. T., Wright, T. L.: Mineralogy of sulfides from certain Hawaiian basalts. Econ. Geol. 63, 636–644 (1968)
Desborough, G. A., Heidel, R. H., Czamanske, G. K.: Improved quantitative electron microprobe analysis using low operating voltage. II. Sulfur. Am. Mineral. 56, 2136–2141 (1971)
Einaudi, M. T.: Copper zoning in pyrite from Cerro de Pasco, Peru. Am. Mineral. 53, 1748–1752 (1968)
Fleischer, A.: Minor elements in some sulfide minerals. Econ. Geol. Fiftieth Anniversary Vol. II, 970–1024 (1955)
Frenzel, G., Ottemann, J.: Eine Sulfid-paragenese mit kupferhaltigem Zonarpyrit von Nukudamu/Fiji. Mineral. Deposita 1, 307–316 (1967)
Haughton, D. R., Roeder, P. L., Skinner, B. J.: Solubility of sulfur in mafic magmas. Econ. Geol. 69, 451–467 (1974)
Kesler, S. E., Issigonis, M. J., Brownlow, A. H., Damon, P. E., Moore, W. J., Northcote, K. E., Preto, V. A.: Geochemistry of biotites from mineralized and barren intrusive systems. Econ. Geol. 70, 559–567 (1975)
Merwin, H. E., Lombard, R. J.: The system Cu-Fe-S. Econ. Geol. 32, 203–284 (1937)
Neuerburg, G. J.: Deuteric alteration of some aplite-pegmatites of the Boulder batholith, Montana, and its possible significance to ore deposition. Econ. Geol. 53, 287–299 (1958)
—: A method of mineral separation using hydrofluoric acid. Am. Mineral. 46, 1498–1501 (1961)
Newhouse, W. H.: Opaque oxides and sulfides in common igneous rocks. Bull. Geol. Soc. Am. 47, 1–52 (1936)
Nickel, E. H.: Structural stability of minerals with the pyrite, marcasite, arsenopyrite, and lollingite structures. Can. Mineral. 9, 311–321 (1968)
—: The application of ligand field concepts to an understanding of the structural stabilities and solid solution limits of sulfides and related minerals. Chem. Geol. 5, 233–241 (1970)
Rehrig, W. A., McKinney, C. N.: The distribution and origin of anomalous copper in biotite. Preprint 76-L-64, AIME Ann. Mtg., Las Vegas, Nevada 1976
Ribbe, P. H., Ed.: Sulfide Mineralogy. Mineral. Soc. Am. 276 pages (1974)
Roberts, S. A.: Pervasive early alteration in the Butte district, Montana. In: Guidebook for the Butte Field Meeting of Society of Economic Geologists. Miller, R. N. (Ed.). HH-1 to HH-8 (1973)
Robertson, F.: Crystallization sequence of minerals leading to formation of ore deposits in quartz monzonitic rocks in the northwestern part of the Boulder batholith, Montana. Bull. Geol. Soc. Am. 73, 1257–1276 (1962)
Shimazaki, H., Clark, L. A.: Synthetic FeS2 solid solution and fukuchilite-like minerals. Can. Mineral. 10, 648–664 (1970)
Skinner, B. J., Peck, D. L.: An immiscible sulfide melt from Hawaii. In: (H. D. B. Wilson, Ed.) Magmatic Ore Deposits. Econ. Geol. Monogr. 4, 310–322 (1969)
Skinner, B. J., Fernandez, L. A., Althaus, E.: Primary sulphide phases precipitated from magmas: their nature and causes of precipitation. Can. Mineral. 11, 580–581 (1972)
Sutherland, J. K.: The chemistry of some New Brunswick pyrites. Can. Mineral. 9, 71–84 (1967)
Tilling, R. I.: The Boulder batholith, Montana: a product of two contemporaneous but chemically distinct magma series. Bull. Geol. Soc. Am. 84, 3879–3899 (1973)
Titley, S. R., Hicks, C., Eds.: Geology of the Porphyry Copper Deposits, Southwestern North America, 287 pages, Tucson, Arizona: University of Arizona Press 1966
Wager, L. R., Vincent, E. A., Smales, A. A.: Sulphides of the Skaergaard intrusion, East Greenland. Econ. Geol. 52, 855–903 (1957)
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Brownlow, A.H., Kurz, S.L. Occurrence, distribution, and composition of sulfide minerals, Boulder batholith, montana. Mineral. Deposita 14, 175–184 (1979). https://doi.org/10.1007/BF00202934
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DOI: https://doi.org/10.1007/BF00202934