English version
	MALMDATABASEN
	Forekomstområde 919 - 027
	(Sist oppdatert 18.okt.2016)

Betydning

Offentlig:

Lokal betydning (reg. 05.05.2015)

Økonomisk:

Ikke vurdert , (Stadfestet 05.mai.2015 av Julian Schilling)

Mineralisering

	Æra:	Proterozoikum	Periode:	Mesoproterosoikum
	Datering:	1060 (-6\+8) million år	Metode:	U/Pb
	Genese:	Pegmatittdannelse	Form:
	Hovedtextur:		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.:

---

Analyseresultater

fra

Forekomstområde 919 - 027 Gloserheia

Elementanalyser

( *=parts pr. million, #=parts pr.billion, Negative verdier betyr under deteksjonsgrensen.)

Prøvenr.	Prøvetype	Cu*	Zn*	Pb*	Co*	Ni*	Au#	As*
O2081402	Fastfjell	2	6	19	2	4	.5	7

------------------

Prøvenr.	Ba*	Mo*	Sb*	Ga*	Th*	U*	Rb*	Sr*	Y*
O2081402	89	0.10	0	17.60	212.30	5.90	21.7	185.9	55.4

------------------

Prøvenr.	Zr*	Nb*	Ta*	Cs*	La*	Ce*	Pr*	Nd*	Sm*
O2081402	501	2.00	0.30	2.00	305.30	742.90	63.68	212.70	34.40

------------------

Prøvenr.	Eu*	Gd*	Tb*	Dy*	Ho*	Er*	Tm*	Yb*	Lu*
O2081402	3.66	24.12	2.66	11.73	1.68	4.82	0.68	4.15	0.70

------------------

Prøvenr.	Be*	Sc*	Hf*
O2081402	6	2.00	16.50

Oksydanalyser

(Alle verdier er i %)

Prøvenr.	Prøvetype	SiO2	Al2O3	TiO2	Fe2O3	MnO	MgO	CaO
O2081402	Fastfjell	69.72	16.52	0.10	1.11	0.02	0.21	3.59

------------------

Prøvenr.	Na2O	K2O	P2O5	Sum
O2081402	6.05	0.57	0.51	98.00

---

Faktaarket ble generert 13.05.2024

Spørsmål eller kommentarer vedrørende faktaarket kan mailes til: ressursdatabaser@ngu.no

Copyright © 2024 Norges geologiske undersøkelse