ABSTRACT
In the Złoty Stok Au-As deposit, unstructured organic matter occurs within the contact between Variscan granitoids and calc-silicates, with rich loellingite mineralization. Unstructured organic matter consists of solid bitumen, with a minor extractable fraction composed mainly of low molecular weight aromatics. Preliminary results of organic geochemical and isotope studies suggest that the hydrocarbons were formed by thermal alteration of indigenous kerogen, and that at least part of the sedimentary/metamorphic cover was not metamorphosed prior to Kłodzko-Złoty Stok intrusion. Based on mineralogical, fluid inclusion and isotopic data, the organic matter underwent strong alteration under conditions exceeding 400 °C and 1.4 kb.
