Title

Barite chimneys on the Gulf of Mexico slope: Initial report on their petrography and geochemistry

Document Type

Article

Publication Date

6-1-1994

Abstract

Barite chimneys associated with hydrocarbonrich fluid venting were recently documented and sampled on the Gulf of Mexico slope offshore Louisiana at 510-520 m water depth. The chimneys are dominated by barite associated with minor amounts of pyrite, iron oxide, Mg calcite, and detrital silicates. The barite displays distinct string-like and dendritic-like morphologies assembled from rosette-shaped crystals that are typically 20-40 μm in diameter. The chimneys exhibit macroscopic growth layers 1-5 mm thick, which alternate between dark gray and light yellow colors. The dark layers are dominated by string barites associated with disseminated pyrite, while the light layers are dominated by dendritic barites with little or no pyrite. The barites are anomalously enriched in Sr (average 15.5 mol% and maximum 30 mol%) and Ca (average 2.8 mol% and maximum 4.6 mol%), and exhibit rhythmic, paired, microscopic light and dark bands. The exact origin of the barites and their mode of deposition has not yet been elucidated, but they are likely to be related to the hydrocarbon-rich fluids venting on the seabed. © 1994 Springer-Verlag.

Publication Source (Journal or Book title)

Geo-Marine Letters

First Page

81

Last Page

87

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