Quartz-apatite-REE phosphates-uraninite vein mineralization near čučma (eastern Slovakia): A product of early alpine hydrothermal activity in the Gemeric Superunit, Western Carpathians

Abstract

The quartz veins with primary fluorapatite, xenotime-(Y), monazite-(Ce) to monazite-(Nd), uraninite, and secondary florencite-(Ce) and goyazite occur in Lower Devonian metavolcano-sedimentary sequence of the Gelnica Group, Gemeric Superunit, the Central Western Carpathians (eastern Slovakia). They represent an example of hydrothermal REE-U mineralization. Fluorapatite forms parallel bands of columnar crystals (≤ 3 cm) in massive quartz. Monazite-(Ce) to (Nd) shows a near end-member composition with very small amounts of cheralite and huttonite components. Widespread xenotime-(Y) forms colloform aggregates or irregular aggregates in association with fluorapatite and monazite. Uraninite electron-microprobe U-Pb dating gave the average age of 207 ± 2 Ma (n = 16, 2σ), which is consistent with formation of the U mineralization in the Gemeric Superunit (e.g., Kurišková uranium deposit) during early Alpine hydrothermal activity.