Molecular biomarkers are the important maturity parameters for sedimentary organic matter. They have also been widely used for determining the maturity of organic matter in ore deposits. However, during the study of organic matter in the Kupferschiefer from the Lubin mine, it had been found that the biomarkers were influenced by sulfide formation. In order to probe into the degree of influence on biomarkers, seven samples collected from a Kupferschiefer section from the Lubin mine were analyzed by various geochemical methods. The results indicated that in the samples with higher copper contents, the values of biomarkers are lower than in the samples with lower copper contents. In highly mineralized samples, hydrogen donation for thermochemical sulfate reduction (TSR) occurred in alkylated phenanthrenes and naphthalenes, leading to the decrease of 12 biomarker parameters during the Kupferschiefer mineralization.
Generally, sandstone-type uranium deposits can be divided into three zones according to their redox conditions: oxidized zone, ore zone and reduced zone. The Dongsheng uranium deposit belongs to this type. In order to study its geochemical characteristics, 11 samples were taken from the three zones of the Dongsheng uranium deposit. Five samples of them were collected from the oxidized zone, four samples from the ore zone and two samples from the reduced zone. These samples were analyzed using organic and inorganic geochemical methods. The results of GC traces and ICP-MASS indicate that the three zones show different organic and inorganic geochemical characteristics.
The bulk composition of organic matter and saturated and aromatic hydrocarbons extracted from 16 samples collected from two Kupferschiefer profiles in the Rudna mine, Southwest Poland has been analyzed to study the role of organic matter during base metal enrichment in the Kupferschiefer shale. The results indicated that the extract yields and saturated hydrocarbon yields decreased with increasing base metal contents. GC and GC/MS analyses indicated that n-alkanes and alkylated aromatic compounds were depleted and may have served as hydrogen donators for thermochemical sulfate reduction. The enrichment of base metals is closely connected with the destruction of hydrocarbons.
