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Missouri Barite Districts |
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Missouri, USA |
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Ba
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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A number of barite districts are known in central and south-east Missouri. The Southeastern district is within the counties of Franklin, St. Francois and Washington, whilst the counties of Benton, Camden, Cole, Miller, Moniteau and Morgan comprise the Central district. Although the latter region is the larger of the two, its production of barite is far less than that of the other.
In South-east Missouri, where barite and lead ore are present together in surficial and near-surface deposits, there are extensive low grade residual deposits resulting from the weathering and dissolution of carbonate host rocks. Ore minerals include barite, galena, cerussite, anglesite, sphalerite, smithsonite and chalcopyrite. The Cambrian Potosi Dolomite is the most important host unit, followed by the Eminence Dolomite. Because galena, sphalerite and barite are less soluble than dolomite, chemical weathering of the host dolomite resulted in the concentration of ore minerals in the residuum. Most of the barite and lead mining was in the residuum, which averages 3 to 5 m in thickness. The total production of barite from the Southeast Missouri Barite District and the Valles Mines is estimated to have been about 11.9 million tonnes, whilst the total lead and zinc production from the Southeast Missouri Barite District and the Valles Mines is estimated at 165 000 tonnes of lead and 55 000 tonnes of zinc.
The central Missouri Barite District is defined by a series of small high grade barite deposits in the form of open space fillings in solution collapse structures in carbonate rocks, including solution fissure and breccia zones, solution channels and 'filled sinks'. The barite deposits occur in a structural high along the northwestern flank of the Ozark uplift, centrally located between the Forest City, Illinois and Arkoma basins. The deposits occur throughout a gently dipping late Cambrian to Late Carboniferous (Pennsylvanian) sedimentary sequence that is principally composed of carbonates with coal, shales and sandstone. The bulk of the barite mineralisation, however, is hosted by the Lower Ordovician Jefferson City and Gasconade Dolomite Formations of the Canadian Series and are located preferentially in solution collapse structures along the crests of gentle anticlinal flexures. Barite both replaces and cements the original fragments and penetrates both fragments and wall rocks as very narrow, irregular veins. The paragenetic sequence comprises initial pyrite-marcasite, followed by galena, sphalerite, barite and calcite with chalcopyrite occurring throughout the sequence (Leach, 1980). Fine-grained massive white barite is by far the dominant economic mineral. Fluid inclusion studies in the area (Leach, 1979, 1980; Coveney et al., 1987) indicate sphalerite precipitated from brines at 80 to 110°C with >22 wt.% salts, whilst barite fluid inclusions suggest precipitation from brines at <50°C with 4 to 10 wt.% salts (Symons and Sangster, 1990). These data are interpreted to indicate the lead-zinc and barite represent two distinct, possibly unrelated events. Lead was the principal product with minor zinc in the district from 1830 to 1910, after which, the district produced barite with lead as a by-product. Production ended in the 1950s.
Studies show the barite to be distinctly later than the lead-zinc mineralisation of the Old Lead Belt and Virburnum Trend, also in Missouri
These deposits have historically made Missouri one of the world's leading producers of barite.
For detail see the reference(s) listed below.
The most recent source geological information used to prepare this decription was dated: 1980.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
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Kaiser C J, Kelly W C, Wagner R J, Shanks W C 1987 - Geologic and geochemical controls of mineralization in the Southeast Missouri Barite district: in Econ. Geol. v82 pp 719-734
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Leach D L 1980 - Nature of mineralizing fluids in the barite deposits of central and southeast Missouri: in Econ. Geol. v75 pp 1168-1180
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Symons, D.T.A. and Sangster, D.F., 1991 - Palcomagnetic Age of the Central Missouri Barite Deposits and Its Genetic Implications: in Econ. Geol. v.86, pp. 1-12.
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Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
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