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???? DATABASEN
Forekomst 0 - 000 FEIL
(Objekt Id: )
(Sist oppdatert: 18.10.2016)

Lokalisering
Fylke: Kommune: Mangler ()
Kart 1:50000: Nelaug (1612-3) Kart 1:250000: Arendal
Fylke: UTM-Zone 33 - EUREF89/WGS84

Ressurs
Ressurstype: Spesialmetaller (Nb,Ta,Be,Li,Sc,REE) Ressursundertype: REE-metaller
Element(er): REE
Betydning
Råstoffbetydning: Lokal betydning (reg. 05.05.2015)

Ressurser og produksjon
Aktivitet: Gruvedrift Reserver: 4000 tusen tonn
Driftsmetode: Dagbrudd Historisk produksjon: 200 tusen tonn


Mineralisering
Æra: Proterozoikum Periode: Mesoproterosoikum
Datering: 1060 (-6\+8) million år Metode: U/Pb
Genese: Pegmatittdannelse Form:
Hovedtekstur: Min. fordeling:
Kornstørrelse: Grovkornet (>3 mm) Hovedomvandling: Muskovittisering
Strøk/Fall: Retning:
Feltstupning:
Stratigrafisk klassifikasjon av vertsbergart
Æra: Periode:
Provins:
Geotek.enhet:
Tektonisk complex:
Intrusivt komplex:
Gruppe: Formasjon:

Mineralogi
Relasjon Mineral Mengde
Gangmineral Plagioklas Hovedmineral (>10%)
Gangmineral Biotitt Hovedmineral (>10%)
Gangmineral Kvarts Hovedmineral (>10%)
Gangmineral Muskovitt Hovedmineral (>10%)
Gangmineral Mikroklin Underordnet mineral (1-10%)
Malmmineral Apatitt Underordnet mineral (1-10%)
Malmmineral Monazitt Aksessorisk mineral (<1%)
Malmmineral Xenotim Aksessorisk mineral (<1%)
Malmmineral Allanitt Aksessorisk mineral (<1%)
Malmmineral Euxenitt Aksessorisk mineral (<1%)

Litologi:
Relasjon Bergart Opprinnelse
Vertsbergart Pegmatite
Sidebergart Pelitic gneis

Opplysning(er) i fritekstformat
Fri tekst
The desposit is situated 0.5 km sotuh of Lake Selestølvann. Its is a well well developed and regular zoned pegmatite with a quartz core. The zoning in the pegmatite is devided in to 5 zones + a quarts core. The most important caracteristics of the zoning can be summarised as follows: Zone 1: quartz with biotite ad microcline. Zone 2 : monomineralic plagioclase. Zone 3: thin zone with occurence of rare minerals like allanite, euxinite and apatite. Zone 4: Graphic feldspar Zone 5: graphic feldspar with myrmecite. R. Åmli gives a detailed description of this pegatite and its mineralogy and zoning and the REE content of apatite and xenotime from the deposits The pegmatite is today known to be the locatlity for the worlds largest occurence of allanite crystals and is suitable, for collectetion of allanite for rare earth separation research. It is one of the deposits investigated as part of the Eurare project.

Litteraturfortegnelser:
Fra NGU's Referansearkiv.:
Baadsgaard, Halfdan; Chaplin, Catherine; Griffin, William L. , 1984
Geochronology of the Gloserheia pegmatite, Froland, southern Norway.
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.64 (1);111-119 sider
Abstrakt:
Relatively unaltered feldspars from the Gloserheia pegmatite yield an Rb-Sr isochron age of 1062 ± 11 Ma (M.S.W.D. = 90, Sr1 = 0.7023 ± 0.0002) and Pb-Pb isochron age of 1085 ± 28 Ma. The best age of pegmatite crystallization is given by a U-Pb concordia-discordia intersection at 1060 (+8, -6) Ma. from euxenite samples. The radiometric age limit the last major metamorphism in the area to > 1060 Ma, although mild later hydration has reset Rb-Sr mineral dates on muscovite and biotite to as low as ~850 Ma. O, Sr and Pb isotope data indicate that the pegmatite magma was derived from a mantle source.

Åmli, Reidar , 1977
Internal structure and mineralogy of the Gloserheia granite pegmatite, Froland, Southern Norway.
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.57 (3);243-262 sider
Abstrakt:
The GLoserheia granite pegmatite shows a well developed and regular zoning around the quartz core. Eight different zones have been recognized. The following minerals occur, quartz, microcline, plagioclase, biotite, muscovite, muscovite 1 M, chlorite, apatite, calcite, tourmaline, rutile, yttrotitanite, magnetite, hematite, pyrite, beryl, zircon, allanite, uraninite, thorite, xenotime, monazite, euxenite, fourmarierite, kasolite, ß-uranophane and uranophane.

Åmli, Reidar , 1975
Mineralogy and rare earth geochemistry of apatite and xenotime from the Gloserheia granite pegmatite, Froland, southern Norway.
;TIDSSKRIFTARTIKKEL;American mineralogist; No.60;607-620 sider
Abstrakt:
The Gloserheia granite pegmatite, situated in the Precambrian Kongsberg-Bamble formation, contains eight different zones (core, intermediate zones I-V, wall zone, and border zone). Apatite occurs in the core and in zones I and III. Xenotime has been found included in apatite from all three zones, and in other parageneses within these zones. The apatite close to xenotime inclusions is depleted in REE. Zoning of xenotime is characterized by an enrichment of the light REE relative to the heavy REE, from the center towards the rim of the crystal. Xenotime crystals included in apatite from the outer zones show less relative enrichment in the light REE than do those in the inner zones of the pegmatite. No such trend in REE fractionation is shown by xenotimes from other parageneses. The rare earth minerals included in apatite are considered to have formed by exsolution, possibly accompanied by metasomatism. Fractionation in the apatite-xenotime system was caused by processes bearing a simple relation to the crystallization of the zones where these minerals occur. In contrast, the REE fractionation in the other xenotimes probably has a more complex relation to the sequence of zones in the pegmatite.

Åmli, Reidar , 1973
The Gloserheia granite pegmatite. Selected studies in geology, mineralogy and rare earth geochemistry.
;UiO Geografisk inst.;AVHANDLING

Feltprøver
Prøvenr. Prøvetype Diverse
O2081402 Fastfjell
Kommentar: Gloserheia border zone
Antall registrerte elementanalyser = 1
Antall registrerte oksydanalyser = 1
NB! Alle analyseverdier er vist i slutten av utskriften.:


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