Fern complex pegmatites.

COUNTY: Florence TOPO. QUAD.:

LOCATION: Scattered outcrops through heavily wooded terrane in sec. 22 T.39N. R.17E., near the Pine River. Note: area now very close to the Pine River Wild Rivers Area, and collecting may be restricted or forbidden.

Fern Pegmatite outcrop, WI

Outcrop of the lepidolite and elbaite bearing Fern pegmatite, Florence County, WI.

 

GEOLOGY: Swarm of small zoned complex Li-rich pegmatites cross-cutting the Quinnessec quartz-biotite schists and amphibolites. Likely a late stage differentiate of the nearby Hoskins Lake Granite. One of these is likley the "Animikie Red Ace" referred to by Falster.

MINERALOGY NOTES:

Alluaudite- varulite
Amblygonite
Apatite
Bermanite
Behierite
Beryl - beige masses up to 1.5 cm. long.
Columbite-tantalite - minute xls,. up to 2 mm.
Elbaite - Red to blue to bicolor subhedral to euhedral xls. up to 4 cm. long.
Fillowite
Griphite
Hambergite
Huttonite
Heterosite-Purpurite - crusts on triphyllite nodules.
Lepidolite - coarse to fine purple scaley.
Lithiophyllite
Manganapatite
Manganocolumbite - crudely to complexly zoned xls. in the Animikie Red Ace dike.
Manganotantalite - complexly zoned xls. in the Animikie Red Ace dike.
Microcline - perthitic pink to grey cleavable masses up to 12.5 cm. across.
Microlite - with lepidolite in the Animikie Red Ace dike.
Muscovite - light green to yellow cluster and flakes. Both primary and secondary.
Opal - clear crusts, green fluorescence.
Plagioclase - some as albite variety cleavelandite, other as andesine in cleavable masses.
Quartz - grey masses, up to 4 cm. across.
Rhodizite
Schorl - black masses to radiating clusters up to 20 cm. across.
Sicklerite ?
Spessartine
Spodumene - white to pale green cleavable masses.
Stibiotantalite
Tantite - rare in contact zone of the Animikie Red Ace dike.
Triphylite - Green nodules up to 4 - 5 mm. across.
Uraninite
Wodginite - sparse, as overgrowths on columbite-tantalite
Zinnwaldite

BIBLIOGRAPHIC REFERENCES: Falster, Simmons and Moore, 1988; Koehler, 1988,1989 pers. comm., Falster, 1992, pers. comm.; Falster, Simmons and Webber, 1995, Falster et. al., 2000.

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