Microscopisch en Kolenpetrografisch onderzoek van Xylieten

Xylites from Upper-Cretaceous (Santonian) sediments (Klei van Hergenrath), South-Limburg/Netherlands, have been investigated by methods of coal-petrography (reflectivity, moisture content, shrinking, microscopy) and organicgeochemistry (extraction, thin-layer chromatography, gas liquid chromatography). According to their moisture content (60%) and schrinking (40%) these woody lignites with the rank of soft-browncoal can be compared with the Tertiary softbrowncoal from the 'Haupt- and Oberflöz' (Upper- and Lower seam) of the 'Rheinische Braunkohle', (German Federal Republic). The reflectivity of 0,31 - 0,34% (Rm, oil, 546 nm), the microscopical investigation and the organic-geochemical results are in confirmation with the above mentioned rank. The coalification is still in the biochemical phase.