Microbial origin for pedogenic micrite associated with carbonate paleosol (Champagne, France)

Détails

ID Serval
serval:BIB_8DD4AC69CF3D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Microbial origin for pedogenic micrite associated with carbonate paleosol (Champagne, France)
Périodique
Sedimentary Geology
Auteur(s)
Loisy C., Verrecchia E.P., Dufour P.
ISSN
0037-0738
Statut éditorial
Publié
Date de publication
1999
Peer-reviewed
Oui
Volume
126
Pages
193-204
Langue
anglais
Résumé
Micro-rods have been observed in indurated carbonate horizons (30 cm thick) that overlie a periglacial chalk formation, in contact with the present-day soil (Champagne, France). They are numerous in the upper part of the hardened layers. Variations in micro-rod morphologies are related to progressive biomineralization of organic matter, transforming purely organic rods into calcite. Mineralized rods undergo diagenesis and their arrangement evolves from a random mesh fabric to recrystallized micritic platelets to microsparite. Two types of organic micro-rods have been observed: bacilliform and thread-like bacteria. Mineralogically, micro-rods are low-magnesian calcite. Crystallographically, their length is parallel to the (104) axis and they grow along the {010} plane. Micro-rods can be associated with needle-fiber calcite. They increase the CaCO3 content of the primary matrix and infill its microporosity. Their diagenetic evolution into microsparite contributes to soil layer induration.
Mots-clé
Bacteria, Calcrete, Champagne, Diagenesis, Holocene, Microbial carbonate
Création de la notice
13/01/2010 10:22
Dernière modification de la notice
20/08/2019 15:51
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