Accelerated transformation of organic matter below the silica transition zone in immature sediments from the Japan Sea

Eric Lichtfouse (1) , Jürgen Rullkötter

1 ASD - Agronomy for Sustainable Development

Notable compositional changes of organic matter are observed below the silica transition zone in thermally immature sediments. The increase of bitumen ratio, and hopane and sterane isomerisation parameters indicate an acceleration of the kinetics of the chemical reactions which transform the organic matter. This phenomenon is probably due to the numerous mineral and textural changes induced by the transformation of amorphous biogenic silica into crystalline authigenic silica.

Mots clés: Japan Sea; sediment; silica; hopane; sterane; molecular parameter; bitumen; oil; diagenesis; biomarker

Domaines: Chimie analytique; Océan, Atmosphère; Interfaces continentales, environnement; Géochimie; Paléontologie

Eric Lichtfouse, Jürgen Rullkötter. Accelerated transformation of organic matter below the silica transition zone in immature sediments from the Japan Sea. Organic Geochemistry, 1994, 21 (5), pp.517-523. ⟨10.1016/0146-6380(94)90102-3⟩. ⟨hal-00191110⟩