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	THE ORE DATABASE
	Deposit Area 919 - 027
	(Last updated 18.okt.2016)

Importance

Public:

Local Importance (reg. 05.05.2015)

Economical:

Not classified/evaluated , (Confirmed 05.mai.2015 by Julian Schilling)

Mineralization

	Era:	Proterozoic	Period:	Mesoproterozoic
	Dating:	1060 (-6\+8) million year	Method:	U/Pb
	Genesis:	Pegmatite formation	Form:
	Main texture:		Min. distribution:

Main grain size:

Coarse grained (> 3 mm)

Main alteration:

Muscovitisation

	Strike/Dip:		Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Period:

	Province:
	Geotec.unit:
	Tectonic complex:
	Igneous complex:

Group:

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Plagioclase	Major mineral (>10%)
	Gangue mineral	Biotite	Major mineral (>10%)
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Muscovite	Major mineral (>10%)
	Gangue mineral	Microcline	Subordinate mineral (1-10%)
	Ore mineral	Apatite	Subordinate mineral (1-10%)
	Ore mineral	Monazite	Accessory mineral (<1%)
	Ore mineral	Xenotime	Accessory mineral (<1%)
	Ore mineral	Allanite	Accessory mineral (<1%)
	Ore mineral	Euxenite	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Host rock	Pegmatite
	Wall rock	Pelitic gneis

Information(s) in free text format

Free text

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.

Bibliography:

From NGU's Reference Archive:

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 pages

Abstract:

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 pages

Abstract:

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 pages

Abstract:

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

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	O2081402	Bedrock	Comment :Gloserheia border zone No. of registrated element analyses = 1 No. of registrated oxide analyses = 1

NB! All analyse values are shown at the end of the printout.:

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Analyse Results

from

Deposit Area 919 - 027 Gloserheia

Element analyses

( *=parts pr. million, #=parts pr.billion, Negative values means below detection limit value.)

Sample No.	Sample Type	Cu*	Zn*	Pb*	Co*	Ni*	Au#	As*
O2081402	Bedrock	2	6	19	2	4	.5	7

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Sample No.	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

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Sample No.	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

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Sample No.	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

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Sample No.	Be*	Sc*	Hf*
O2081402	6	2.00	16.50

Oxide analyses

( All values are in % )

Sample No.	Sample Type	SiO2	Al2O3	TiO2	Fe2O3	MnO	MgO	CaO
O2081402	Bedrock	69.72	16.52	0.10	1.11	0.02	0.21	3.59

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Sample No.	Na2O	K2O	P2O5	Sum
O2081402	6.05	0.57	0.51	98.00

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The fact sheet was created on 28.04.2024

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