Muscovite-Rare-element Pegmatite

Abbreviation

MSREL

Classification

Muscovite-Rare-element class < Granitic pegmatite

Required Geological Setting

Middle-pressure metamorphic rocks, Low-pressure metamorphic rocks

Occurrence

Pegmatite associated with upper Amphibolite facies in Barrovian-type middle-P metamorphism or Ryoke-type low-P metamorphism. Formation condition is 580-650 degree and 0.2-0.5 GPa (5-12 km depth). Pegmatites are associated with S-type granites or I-type granites intruded in metamorphic rocks subjected to Amphibolite facies metamorphism, and mineral assemblages include those of Muscovite Pegmatite and Rare-element Pegmatite. Pegmatites are usually disconcordant with schistose textures of host metamorphic rocks subjected to Amphibolite facies metamorphism. Pegmatites are massive and pockets are very rare. This class is classified into 2 subclasses based on its mineral assemblages; MSREL-REE and MSREL-Li. Pegmatites associated with Ryoke-type low-P metamorphism have unique mineral assemblages, and are tentatively separated as MSREL-Al subclass.

Mineral Assemblages (Major minerals)

Quartz, Microcline, Albite, Muscovite

Mineral Assemblages (MSREL-REE subclass)

Beryl, Fergusonite-(Y), Samarskite-(Y), Monazite-(Ce), Almandine, Spessartine

Mineral Assemblages (MSREL-Li subclass)

Beryl, Cassiterite, Columbite-(Fe), Lepidolite, (Spodumene)

Mineral Assemblages (MSREL-Al subclass)

Andalusite, Cordierite, Almandine