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	MALMDATABASEN
	Forekomstområde 437 - 033
	(Sist oppdatert 08.mai.2006)

Betydning

Offentlig:

Little Importance (reg. 18.02.2015)

Economical:

Lite viktig

Operations

	From - To	Activity	Comments
		Pitting
	1998 - 1998	Sampling	Company/Institution :NGU mineralressurser

Mineralization

	Era:	Paleozoic	Period:	Ordovician
	Dating:		Method:
	Genesis:	Kjemisk sediment	Form:	Lag
	Main texture:	Båndet	Min. distribution:	Semi-massiv

Main grain size:

Finkornet (<1 mm)

Main alteration:

	Strike/Dip:	64 / 90	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Paleozoic

Period:

Ordovician

	Province:	Caledonides
	Geotec.unit:	Trondheim Nappe Complex
	Tectonic complex:	Gula Nappe
	Igneous complex:

Group:

Gula Group

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Muscovite	Major mineral (>10%)
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Garnet	Subordinate mineral (1-10%)
	Gangue mineral	Biotite	Subordinate mineral (1-10%)
	Gangue mineral	Graphite	Subordinate mineral (1-10%)
	Gangue mineral	Chlorite	Subordinate mineral (1-10%)
	Ore mineral	Pyrrhotite	Major mineral (>10%)
	Ore mineral	Magnetite	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Host rock	Biotite-muscovite schist	Sedimentary Original rock :Greywacke
			Metamorphic facies :Greenschist

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Foliation	Strike/Dip :64 / 90	Post-mineralisation ;...Effect :Controls

Opplysning(er) i fritekstformat

Fri tekst

Skjerpet ligger ca. 1 km nordvest for Moan-Langsætra og like i skoggrensa. Det er sprengt på flere steder over en strekning på 50 m langs strøket, dvs. i NNØ-SSV retning. Hovedrøsken er en grop 3.5 m på tvers av strøket, 2 m bred og inntil 1 m dyp. Den mineraliserte sonen er ca. 3.5 m mektig og synes å være isoklinalt foldet. Det er flere parallelle soner i skjerpområdet og en 1 m bred rustsone 10 m øst for hovedrøsken sees å være foldet inn i den omgivende muskovittskiferen. Ellers kan sonen følges sør-sørøstover og opp på snaufjellet i ca. 700 m, hvor mektigheten avtar til ca.1 m. Ca. 100 m vest er det en parallellsone hvor det også er røsket i en skrent (Rødhammer - HE0160). Mineraliseringen består vesentlig av finkornet rik impregnasjon til semimassiv båndet mineralisering (1-10 mm skala) av magnetkis i grafittrik muskovitt-kvartsskifer. Magnetkis opptrer også impregnert i kvartslinser i skiferen. Mot sidebergart, men også som linser i denne opptrer biotitt-granat-klorittskifer med spredt magnetkis. Denne går gradvis over i muskovittskifer med hyppige biotitt-blaster og spredt granat som igjen går over i uomvandlet psammittisk muskovittskifer.

Bibliography:

From NGU's Reference Archive:

Nilsen, Odd , 1978

	Caledonian sulphide deposits and minor iron-formations from the southern Trondheim region, Norway.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.340;35-85 + k pages

Abstract:

Within the southern and central parts of the Trondheim region of the Norwegian Caledonides a great number of small, stratabound cupriferous pyrite deposits are confined to mafic metavolcanics of the Gula, Støren and Fundsjø Groups of the Lower Palaeozoic succession. The deposits occuring within, or in close contact with the metavolcanics are characterized by their association with minor manganiferous oxide/silicate iron-formations - better known as "vasskis" ore type - within the metamorphic low-grade areas. The iron-fprmations of the metamorphic higher grade terrains on the other hand, which are extensively developed within the Gula Group, are mostly of a pyrrhotitic sulphide/silicate type and sulphurization processes are thought to have played an important role during the metamorphism. The pyrite deposits occurring adjacent to the metavolcanics bear no relationship to the iron-formations. They are embedded in pelitic, often carbonaceous assemblages (Gula Group) or within tuffitic members of the volcanogene Støren Group, and they are thought to represent re-sedimented (reworked) deposits. The pyrite deposits display varying degree of metamorphic reconstitution and a tectonic control has apparently determined their disc- or ruler-shaped morphology.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	HE0130.01	Dump	Sampler :T. Bjerkgård/...Stored :Løkken/...Size(kg) :3 Kommentar :Banded semimassive pyrrhotite in graphite-bearing muscovite-quartz schist. No. of registrated element analyses = 1
	HE0130.02	Bedrock	Sampler :T. Bjerkgård/...Stored :Løkken/...Size(kg) :3 Kommentar :Banded semimassive pyrrhotite in graphite-bearing muscovite-quartz schist. Bedrock sample 40 m north from main trench. No. of registrated element analyses = 1
	HE0130.03	Bedrock	Sampler :T. Bjerkgård/...Stored :Løkken/...Size(kg) :3 Kommentar :Biotite-garnet-chlorite schist with streaks of pyrrhotite. Sample from contact zone east of main trench. No. of registrated element analyses = 1

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

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Analyse Results

from

Forekomstområde 437 - 033 Fosstjønna

Element analyses

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

Sample No.	Sample Type	Cu*	Zn*	Pb*	Co*	Ni*	Ag*	Au#
HE0130.01	Dump	902	811	121	49	115	.3	64.0
HE0130.02	Bedrock	515	591	81	36	112	-.3	21.0
HE0130.03	Bedrock	63	324	-3	12	39	-.3	2.0

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Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	V*
HE0130.01	8.0	11.0	11	7.4	23	23.00	12	-3	47
HE0130.02	6.0	8.0	7	3.9	16	8.00	-3	-3	38
HE0130.03	9.0	2.0	-2	1.4	11	-1.00	-3	-3	73

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Sample No.	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*	B*
HE0130.01	11	448	31.89	8.00	-8.00	-2	26.0	19.00	30
HE0130.02	10	377	26.31	8.00	11.00	-2	33.0	35.00	17
HE0130.03	46	1211	10.44	12.00	-8.00	-2	23.0	19.00	6

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Faktaarket ble generert 10.06.2026

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

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