Title

Regional Epigenetic Dolomitization in the Bonneterre Dolomite (Cambrian), Southeastern Missouri

Abstract

A dolomite bed averaging 6 m in thickness forms the base of a limestone and shale facies of the Bonneterre Dolomite (Cambrian), southeastern Missouri. It is proposed that this basal dolomite formed as a result of interaction with warm, basin-derived water circulating through the underlying Lamotte Sandstone, and that the dolomitization event coincided with the emplacement of Mississippi Valley-type sulfide ores in the nearby Viburnum Trend. This hypothesis is supported by (1) petrographic evidence that suggests an origin at temperatures > 50°C, (2) cathodoluminescent microstratigraphy of dolimite cements which is correlative with that in gangue dolomite cements in the nearby orebodies, and (3) stable oxygen and carbon isotope values that are consistent with a basinal origin of the dolimitizing water. The basal dolomite bed may represent one of the most extensive epigenetic dolomites yet documented. This implies that a basinal water can alter rocks over a wide area at a considerable distance from its source.

Department(s)

Geosciences and Geological and Petroleum Engineering

Geographic Coverage

Southeastern Missouri

Time Period

Cambrian

International Standard Serial Number (ISSN)

0091-7613

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1985 Geological Society of America (GSA), All rights reserved.

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