RESUMO
Southern Siberia demonstrates significant richness of the geological environment, but its uniqueness remains known poorly. Four geosites represent sections of Givetian-Famennian (Middle-Late Devonian) deposits formed in the tectonically active zone where small terranes accreted with the Siberian continent. There, carbonate deposition in tropical conditions prevailed and rich ecosystems evolved. Three geosites are dominated by the unique palaeogeographical features (notable palaeobiogeographical changes, facies of catastrophic outflow from palaeolake, Frasnian/Famennian mass extinction, and palaeoreefs), and one geosite is dominated by the stratigraphical feature (regionally representative section of the Frasnian/Famennian boundary). Additionally, all localities are rich in Devonian marine invertebrates, and one of them is also a topographical expression of palaeoreef. The semi-quantitative assessment of these geosites implies that one of them can be ranked nationally and three others can be ranked regionally. All localities are well accessible and important for international research. It is proposed to use these geosites for a new geopark development that would facilitate geotourism growth in the study area and, thus, provide socio-economic benefits to the region.
RESUMO
Raman micro-spectroscopy is a non-destructive and non-contact analytical technique that combines microscopy and spectroscopy, thus providing a potential for non-invasive and in situ molecular identification, even over heterogeneous and rare samples such as fossilized tissues. Recently, chemical imaging techniques have become an increasingly popular tool for characterizing trace elements, isotopic information, and organic markers in fossils. Raman spectroscopy also shows a growing potential in understanding bone microstructure, chemical composition, and mineral assemblance affected by diagenetic processes. In our lab, we have investigated a wide range of different fossil tissues, mainly of Mesozoic vertebrates (from Jurassic through Cretaceous). Besides standard spectra of sedimentary rocks, including pigment contamination, our Raman spectra also exhibit interesting spectral features in the 1200-1800 cm-1 spectral range, where Raman bands of proteins, nucleic acids, and other organic molecules can be identified. In the present study, we discuss both a possible origin of the observed bands of ancient organic residues and difficulties with definition of the specific spectral markers in fossilized soft and hard tissues.
