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	MALMDATABASEN
	Forekomstområde 437 - 019
	(Sist oppdatert 08.mai.2006)

Betydning

Offentlig:

Little Importance (reg. 18.02.2015)

Economical:

Lite viktig

Operations

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

Mineralization

	Era:	Proterozoic	Period:	Neoproterozoic
	Dating:		Method:
	Genesis:	Vulkeks	Form:	Linse
	Main texture:	Strukturløs	Min. distribution:	Semi-massiv

Main grain size:

Finkornet (<1 mm)

Main alteration:

Biotittisering

	Strike/Dip:	30 / 65	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Proterozoic

Period:

Neoproterozoic

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

Group:

Gula

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Amphibole	Subordinate mineral (1-10%)
	Ore mineral	Pyrrhotite	Major mineral (>10%)
	Ore mineral	Magnetite	Subordinate mineral (1-10%)
	Ore mineral	Hematite	Accessory mineral (<1%)
	Ore mineral	Pyrite	Accessory mineral (<1%)
	Ore mineral	Chalcopyrite	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Wall rock	Fyllittisk glimmerskifer	Sedimentary Original rock :Argillaceous sediment
			Metamorphic facies :Amphibolite
	Wall rock	Amfibolitt	Extrusive Original rock :Basalt
			Metamorphic facies :Amphibolite

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Wall rock	Schistosity	Strike/Dip :20 / 70	Post-mineralisation ;...Effect :Modifies
	Wall rock	Foliation	Strike/Dip :30 / 65	Post-mineralisation ;...Effect :Modifies

Opplysning(er) i fritekstformat

Fri tekst

Skjerpet ligger på¨sørsida av en liten rygg ca. 300 m nordvest for Strålbergsetra. En grop på 3 x 3 m som er opptil 1 m dyp er utsprengt. Det er usikkert når skjerpingen foregikk, men det er inntegnet på et kart over Rødalsfeltet fra 1910 (Aalen 1910). Mineraliseringen er 20-30 cm mektig og består av en minimum 10 cm bred sone med massiv magnetkis (prøve .01) omgitt av svakere disseminasjon av magnetkis i kvarts-amfibol rik grunnmasse. Lokalt finnes biotittanrikning og tynne karbonatårer. Den mineraliserte sona ligger i finkornet amfibolitt med foliasjon 30°/65°. Ca. 5 m vest for skjerpet finnes fyllittisk glimmerskifer som ligger tektonostratigrafisk under amfibolitten. Rustsonen fortsetter videre mot nordnordøst men kun svak disseminasjon av magnetkis forekommer.

Bilde(r) fra forekomstområdet:

Photo no. 1 showing Strålbergsetra skjerp"

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.

Aalen, O. E. , 1910

	Rødals grube. Oversiktskart 1:2 000.

;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 1030

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	HE0116.01	Bedrock	Sampler :J.S. Sandstad/...Stored :Løkken Kommentar :Semi-massiv til sterk disseminasjon av finkornet magnetkis+kobberkis i kvarts og amfibol matriks 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 - 019 Strålbergsetra

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#
HE0116.01	Bedrock	648	43	11	38	81	.6	13.0

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Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	S%
HE0116.01	9.0	11.0	1	.4	96	8.00	2	2	8.36

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Sample No.	V*	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*
HE0116.01	69	20	932	15.79	6.00	4.00	1	47.0	24.00

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Sample No.	B*
HE0116.01	3

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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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