Abstract
The Precambrian epigenetic Ag-W-Sn deposits of the Silver Mine district in southeastern Missouri occur as erratically distributed pods, lenses, and irregularly shaped bodies in quartz veins, contiguous greisen, and greisenized tuff. Ore microscopic examination of 200 polished sections prepared from specimens from nine mines and prospects in the district shows that the primary ores consist of 24 minerals deposited during several stages. Greisen and early vein stages involved the crystallization under xenothermal conditions of quartz, topaz, apatite, sericite, cassiterite, rutile, ilmenite, wolframite, scheelite, zinnwaldite, arsenopyrite, specular hematite, and magnetite. Subsequent stages of base and precious metal deposition consisted of pyrite, marcasite, chlorite, fluorite, sphalerite, pyrrhotite, argentiferous tennantite, antimonpearceite, argentiferous galena, chalcopyrite, berryite, and additional quartz. Fluid inclusion homogenization temperatures for fluorite and sphalerite indicate that the late sulfides and silver-bearing minerals formed under epithermal conditions.
Argentiferous tennantite (Cu11.9Ag0.9As3.71Sb0.95Bi0.01S13) occurs as 100–400 µm grains disseminated in quartz. Antimonpearceite (AS18.8Cu4.28As1.34Sb0.76Bi0.01S11) partially surrounds and veins some argentiferous tennantite grains. Argentiferous galena and argentiferous chalcopyrite (0.17% Ag) surround and partly replace argentiferous tennantite and antimonpearceite. The youngest silver mineral is berryite (Pb3.03Cu3.04Ag3.09Bi9.43Sb0.05S16), which is not found in association with argentiferous tennantite and antimonpearceite. Berryite has formed by the replacement of galena and chalcopyrite and locally it contains tiny irregularly shaped remnants of those two minerals.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Bickford ME, Mose DG (1975) Geochronology of Precambrian rocks in the St Francois Mountains, southeastern Missouri. Geol Soc Am Spec Pap 165: 1–48
Bickford ME, Sides JR, Cullers RL (1981) Chemical evolution of magmas in the Proterozoic terrane of the St Francois Mountains, southeastern Missouri. 1. Field, petrographic, and major element data. J Geophys Res 86 (B11): 10365–10386
Buehler HA (1919) Biennial report of the state geologist, Missouri. Bur Geol Mines, 117 p
Gustayson JB (1977) Geochemical prospecting for porphyry systems in the St Francois Mountains, Missouri (preprint). Soc Mining Eng AIME Fall meeting, 36 p
Karup-Moller S (1966) Berryite from Greenland. Can Mineral 8: 414–423
Kisvarsanyi EB (1972) Petrochemistry of a Precambrian igneous province, St Francois Mountains, Missouri. Missouri Geol Sury Rep Invest 51: 1–103
Kisvarsanyi EB (1980) Granitic ring complexes and Precambrian hot-spot activity in the St Francois terrane, Midcontinent region, United States. Geology (Boulder) 8: 43–47
Lowell GR, Gasparrini C (1982) Composition of arsenopyrite from topaz greisen veins in southeastern Missouri. Mineral Deposita 17: 229–238
Nuffield EW, Harris DC (1966) Studies of mineral sulpho-salts: XX Berryite, a new species. Can Mineral 8: 407–413
Pomerene JB (1947) Geology of the Einstein-Apex tungsten mine area. MS thesis, University Missouri-Rolla, p 70
Singewald JT Jr, Milton C (1929) Greisen and associated mineralization at Silver Mine, Missouri. Econ Geol 24: 569–591
Stevens RP (1958) Paragenesis of the minerals in the Einstein vein, Madison County, Missouri. MS thesis, University Missouri-Rolla, 70 p
Tolman CF (1933) The geology of the Silver Mine area, Madison County, Missouri. In: Biennial report of the state geologist, Missouri bureau of geology and mines, appendix I, 39 p
Wones DR (1980) Intensive parameters during the crystallization of granitic plutons. Geol Soc Am Abs Prog, p 543
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1984 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Hagni, R.D. (1984). Ore Microscopy of the Silver Minerals in the Epigenetic Ag-W-Sn Deposits in the Silver Mine District, Southeastern Missouri, U.S.A.. In: Wauschkuhn, A., Kluth, C., Zimmermann, R.A. (eds) Syngenesis and Epigenesis in the Formation of Mineral Deposits . Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-70074-3_7
Download citation
DOI: https://doi.org/10.1007/978-3-642-70074-3_7
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-70076-7
Online ISBN: 978-3-642-70074-3
eBook Packages: Springer Book Archive