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Fluvial Placer Deposit (REE)

Physical Process - Ground surface


Alluvial placer deposit

Required Geological Setting

Neogene and Quaternary sediments


Fluvial placer deposits where rare earth element (REE) minerals are selectively concentrated by water flows of rivers based on the difference of specific density. The REE fluvial placer deposits are at downstreams of REE containing REE miarolitic pegmatites, abyssal pegmatites, muscovite-rare-element pegmatites, rare-element pegmatite (allanite), rare-element pegmatite (euxenite), and rare-element pegmatite (gadolinite). The REE fluvial placer deposits are formed on the riverbeds at a gently flowing stream in fissures of riverbed slabs or at upstreams of obstacles such as boulders in water.

Mineral Assemblages (Abyssal pegmatites)

Zircon, Euxenite-(Y), Samarskite-(Y), Fergusonite-(Y), Thorite

Mineral Assemblages (REE miarolitic pegmatites)

Cassiterite, Xenotime-(Y), Monazite-(Ce), Fergusonite-(Y), Topaz

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