Bacterially mediated formation of carbonate concretions in the Oligocene Boom Clay of Northern Belgium

de Craen, M., Swennen, R., Keppens, E.M., Macaulay, C.I. and Kiriakoulakis, K. (2000) Bacterially mediated formation of carbonate concretions in the Oligocene Boom Clay of Northern Belgium. Journal of Sedimentary Research, 69(5), pp. 1098-1106.

Abstract

Carbonate concretions in the Oligocene Boom Clay in Northern Belgium grew as a result of bacterially mediated geochemical processes, Concretion distribution patterns are controlled by glacioeustatic controls on water depth and related sediment detrital carbonate contents, Bacterial remains are present throughout these early diagenetic concretions and can be observed by SEM analysis of etched carbonates. The oxygen isotopic composition (delta(18)O similar to 0 parts per thousand) Of the calcite in the concretions indicates early diagenetic growth close to the sediment-water interface, Negative carbon-isotope values (delta(13)C -17 to -22 parts per thousand) from concretion carbonates, as well as pyrite delta(34)S values of -15 to -45 parts per thousand, suggest precipitation resulting from bacterial sulfate reduction during shallow burial diagenesis, Additionally, organic components in the concretions are characteristic of the remains of sulfate- reducing bacteria.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: UNSPECIFIED
• Authors: de Craen, M., Swennen, R., Keppens, E.M., Macaulay, C.I., and Kiriakoulakis, K.
• Subjects: Q Science > QE Geology
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Journal of Sedimentary Research
• ISSN: 1527-1404