Contribution to the origin of Mn-U-Be-HREE-enrichment in phosphorite, near Bükkszentkereszt, NE Hungary

• DOI: 10.1016/j.oregeorev.2020.103665
• Publication Date: 2020-07-04T22:26:56Z
• Authors: Péter Gál; Márta Polgári; Sándor Józsa; Ildikó Gyollai; Ivett Kovács; Máté Szabó; Krisztián Fintor
• Keywords: Phosphorite; Ferrihydrite; Texture (cosmology)

Strongly deformed phosphorite layers enriched with U-Be-Mn-REE occur in a weathered Triassic metarhyolite tuff near the town of Bükkszentkereszt, NE Hungary. The is massive or earthy, has an especially fine-grained texture, and forms inhomogeneous bands different Mn-oxide contents. High-resolution optical rock microscopy investigations helped to distinguish mineralized biosignatures, filamentous, vermiform structures, coccoid-like aggregates. These microstructures encompass almost whole phosphorite. Based on situ FTIR Raman spectroscopy, phosphorites contain ferrihydrite pyrite, also types embedded organic matter. structures can be interpreted as series Fe-rich biomats, forming microbialites. On larger scale, these play role shaping stratiform structure by evolving stromatolite-like bands. Results presented here propose new interpretation origin P-Mn-U-Be-HREE-enrichment. Bükkszentkereszt occurrence claim microbially mediated deposit, our results support this scenario based microbial minerals, presence