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Fig. 10 | Swiss Journal of Geosciences

Fig. 10

From: Triassic radiolarite and carbonate components from a Jurassic ophiolitic mélange (Dinaridic Ophiolite Belt)

Fig. 10

Late Middle to early Late Jurassic (Callovian to Middle Oxfordian) radiolarians and microfacies from the road south of the Katušnica River. Under low temperature suboxic conditions in the sediment, ferric hydroxides were converted to iron sulphides through various reductive processes associated with organic matter degradation. a Eucyrtidiellum cf. unumaense (Yao). b Williriedellum dierschei Suzuki & Gawlick. c Archaeodictyomitra cf. rigida Pessagno. d Gongylothorax cf. favosus Dumitrica. e Tritrabs sp. Sample SRB 216. f Greenish-grey massive radiolarite of Callovian to Middle Oxfordian age. The fissures and partly also the radiolarians are filled by glauconite. Changing fluid chemistry in the factures and the radiolarian tests leads to an increase in the alkalinity with subsequent precipitation of glauconite cement and a degradation of the organic matter. Sample SRB 216. Width of the photo: 1.4 cm. g Magnification of f. Fissures and most radiolaria are filled with glauconite. These radiolaria have only a moderate preservation. The other radiolarians are recrystallized to quartz. Width of the photo: 0.25 cm. h Slightly bioturbated Middle Jurassic red layered radiolarian wackestone in gradual change to layers of biomineralized iron sulphides with altered organic matter. Sample SRB 217. Width of the photo: 1.4 cm. i Magnification of h. Bioturbated radiolarian packstone. All radiolarians are recrystallized. Width of the photo: 0.25 cm

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