Fanerozoické mikroendolitické společenstva: paleoekologie a tafonomie

Herenio Kerkhoff, Marta Leticia

The microbial endoliths study from the Western Carpathians region was a semi-quantitative survey that included six sampling localities. Samples, ranging from Upper Oligocene to Miocene (Serravalian), came from three localities in Czechia (Mikulov, LOM-1 and Hevlín), two in Slovakia (DNV and LKŠ) and one place in Hungary (Tard Clays, Rozalia Quarry). The main goal of this project was to verify how different levels of hypoxia, established for studied intervals, would affect the microendolilthic assemblages present in tests of benthic foraminifera. Additionally, microbial activity and byproducts, and the overall interplay between bioerosion and bioprecipitation are also analysed. The degree of hypoxy was established using ratio of oxic/dysoxic and hypoxic foraminifera, defined as Benthic Foraminifera Oxygen Index (BFOi) Sampled index shows a predominance of dysoxic indicators, with rare oxic elements. Secondary electron elemental analysis (EDX) reveals a significant enrichment of sulphur, phosphorus and iron in biofilm samples from DNV and Hevlín, when compared to the rock matrix surrounding it. Resin casts reveal a predominance of Dysphotic to Deep Euphotic zones ichnocenosis, with a predominance of Chlorophyte, Rodophyte and heterotroph burrows. Few representatives of Cyanobacteria traces, such as...

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