Title

Sequential Deposition of Zoned Dolomite and Its Relationship to Sulfide Mineral Paragenetic Sequence in the Viburnum Trend, Southeast Missouri

Abstract

Dolomite cement crystals from the Viburnum Trend of the Southeast Missouri Lead District exhibit four regionally correlative cathodoluminescent zones. These zoned cements record major mineralizing events that altered rocks throughout the southeast Missouri region, covering an area greater than 30,000 km2 and affecting Upper Cambrian to at least Lower Ordovician rocks. Major dissolution surfaces in the dolomite cement appear to correspond to an early period of karst development and later periods of solution brecciation, associated with Mississippi Valley-type sulfide mineralization. Combined cathodoluminescence and ore microscopic studies have determined the positions of the dolomite zones with respect to the known sulfide mineral paragenetic sequence. The earliest generation of dolomite cement (zone 1) precipitated before the main generation of disseminated sphalerite. Zone 2 dolomite formed after emplacement of disseminated sphalerite but before cube-octahedral galena. Zone 3 dolomite precipitated during the interval between the deposition of cube-octahedral galena and prior to cubic galena. The last zone of dolomite cement (zone 4) formed after the deposition of the early vug-lining crystals of cubic pyrite and chalcopyrite, but prior to the deposition of cubic galena, marcasite, later chalcopyrite, and calcite.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Cement; Mineralization; Paragenetic Sequence; Solution Brecciation; Viburnum Trend; Zoned Cement; USA, Missouri

Geographic Coverage

Southeast Missouri

International Standard Serial Number (ISSN)

0891-2556

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1989 Springer Verlag, All rights reserved.

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