Pore space characteristics of the Upper Visean ‘Rudov Beds’: insights from broad ion beam scanning electron microscopy and organic geochemical investigations

David Misch, Jop Klaver, Doris Groß, Javad Rustamov, Reinhard Sachsenhofer, Joyce Schmatz, Janos Urai

Research output: Chapter in Book/Report/Conference proceedingChapterResearch

2 Citations (Scopus)


This study gives valuable insights into the microstructure and pore space characteristics of 17 compositionally variable Visean shale samples from the Ukrainian Dniepr-Donets Basin (the ‘Rudov Beds’). The representative imaging area varies considerably (from 10 000 to >300 000 μm2) as a function of the mineralogy and diagenetic overprinting. The pores hosted in organic matter (OM) are restricted to secondary solid bitumen. Based on high-resolution maps from broad ion beam scanning electron microscopy combined with organic geochemical and bulk mineralogical data, we propose that the amount of OM-hosted porosity responds to the availability of pore space, enabling the accumulation of an early oil phase, which is then progressively transformed to a porous solid bitumen residue. The type of OM porosity (pendular/interface v. spongy) is reflected in the individual pore size distributions: The spongy pores are usually smaller (<50 nm) than the pendular or OM–mineral interface pores. The OM-hosted porosity coincides with differences in the composition of the extract, with high amounts of extractable OM and saturated/aromatic compound ratios indicative of abundant porous solid bitumen. The average circularity and aspect ratio of the mineral matrix pores correlate with the corresponding values for the OM-hosted pores, which show a preferred bedding-parallel orientation, suggesting that compaction influenced both types of pore.

Original languageEnglish
Title of host publicationGeological Society Special Publication
Place of PublicationLondon
PublisherGeological Society London
Number of pages24
ISBN (Electronic)2041-4927
ISBN (Print)0305-8719
Publication statusPublished - 2020

Publication series

NameGeological Society Special Publication
ISSN (Print)0305-8719

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