Paleozoic black shales of the Saxothuringikum (Germany) with an average Corg. -content of 0.01 to 20 mass% were investigated with regard to the nature of organic matter. A special pyrolysis technique
(DEGAS) was used for a temperature resolved analysis of different hydrocarbons (HC) and the simultaneous detection of inorganic
volatiles during heating under vacuum up to 1450C. The presented data indicate three different forms of organic matter occurring
in the investigated black shales (bitumen, kerogen and pyrobitumen). Finally the influence of an igneous dyke intrusion on
the alteration of the organic matter was examined.
Correlation of structure parameters of glasses and related crystals formed in homogeneous or heterogeneous nucleation processes
by thermal treatment is discussed on the basis of DTA, TG and EGA measurements in relation to the textural patterns of the
materials. For cordierite glass, crystallization of metastable disordered cordierite polymorphs is related to an exothermic
heat evolution and simultaneous with a small weight loss (appr. 0.025%). By MS-EGA, evolution of water was determined during
the transformation of the metastable melt to a metastable intermediate crystalline phase. Interpretation of the crystallization
by comparing the available structure parameters of cordierite glasses and crystals alone is insufficient to explain the role
of water in the kinetics of crystallization. Optical and electron microscopy of the primary crystallization phenomena show
the metastable solid solution with low quartz-type structure. Interpretation of the crystallization behaviour in terms of
conventional theory of nucleation and crystal growth is impossible.
By means of the thermomicroscopy was demonstrated that the discrepancy between the experimental DSC- and TG-data on the decomposition of citric acid in the literature can be explained in terms of superimposing reactions (melting, decomposition, immiscibility, and crystallization), which have different reaction rates. The thermomicroscopy is especially useful explaining such kind of reactions. The thermal behaviour of citric acid can be used as a “model reaction” in technology.