Norsk versjon
	THE ORE DATABASE
	Occurence 3429 - 008 Elgsjøbekken
	(Object Id: 4299) (Last updated: 01.07.1998)

Operations

	From - To	Activity	Comments
	1965 - 1965	Geophysics	Company/Institution :NGU
	1966 - 1966	Geophysics	Company/Institution :Folldal Verk A/S
	1997 - 1997	Sampling	Company/Institution :NGU-Malmreg.

Mineralization

	Genesis:	Volcex	Form:
	Main texture:	Banded	Min. distribution:	Massive (>50 % ore minerals)

Main grain size:

Fine grained (< 1 mm)

Main alteration:

Sericitisation

	Strike/Dip:	35 / 40	Direction:	85
			Plunge:	30

Stratigraphic classification of host rock

Era:

Period:

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

Group:

Støren

Formation:

Elgsjø

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Muscovite	Subordinate mineral (1-10%)
	Gangue mineral	Sericite	Subordinate mineral (1-10%)
	Ore mineral	Pyrite	Major mineral (>10%)
	Ore mineral	Pyrargyrite	Accessory mineral (<1%)
	Ore mineral	Sphalerite	Accessory mineral (<1%)
	Ore mineral	Chalcopyrite	Accessory mineral (<1%)
	Ore mineral	Pyrrhotite	Accessory mineral (<1%)
	Ore mineral	Galena	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Wall rock	Sericite schist	Sedimentary Original rock :Tuffite
			Metamorphic facies :Greenschist

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Wall rock	Foliation	Strike/Dip :35 / 40	Post-mineralisation ;...Effect :None
	Wall rock	Fold axis	Dir./Plunge :85 / 30	Post-mineralisation ;...Effect :Modifies

Information(s) in free text format

Description

Røskingen ved Elgsjøbekken foregikk sannsynligvis i samme periode som på Elgsjøtangen, rundt 1911-12. Etter at NGU utførte magnetiske og elektromagnetiske flymålinger over området i 1965 fortsatte Folldal Verk A/S undersøkelsene, bl.a. med geofysiske bakkemålinger og diamantboring i området Elgsjøbekken - Elgsjøtangen. The deposits of the Elgsjøtangen area display a similar geological setting as the Heimtjønnhø deposit to the south. A mineralized zone, only a few metres in thickness, can be followed for at least 3 km from the Elgsjøtangen prospect to the Elgsjøbekken prospect. To the south it is offset by the major SSE-NNW-trending Vinstra fault. The zone strikes parallel to the axial plane of a tight, recumbent fold in the Elgsjø Formation, traced by a thin greenstone horizon. It is confined to impure quartzitic layers within the tuffaceous sericite-chlorite phyllites. Pyrite is the dominant ore component of these deposits and pyrrhotite may occur as a minor component (Nilsen 1978). Ved Elgsjøbekken, på nordsiden, er det utsprengt ei 10 m lang N-S-gående skjæring (5 m3 tipp). Over en mektighet på 7 m i serisittskifer er det 4 kishorisonter. Den dominerende er en 1.6 m mektig stratiform, finkornig og massiv svovelkis-mineralisering. Den inneholder endel kvarts, som tildels opptrer i mm-cm-skala bånd, og dels som grunnmasse for semimassiv til massiv svovelkis. De 3 andre kishorisontene er 0.2-1 m mektige, med alternerende bånd i cm- til dm-skala av disseminert til semimassiv svovelkis. Kishorisontene synes å ligge stjert-om-stjert (en echelon), og er muligens foldet etter akse 85/30 - eller denne retningen er stupningen på en kisboudin. Det finnes ikke mineralisering (eller rust) i blotninger langs sør-bredden av elva. Bortsett fra langs elva er området overdekket.

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
	ST0096.01	Bedrock	Sampler: Wilberg/...Stored: Løkken Comment: Fink. massiv py-min. No. of registrated element analyses = 1
	ST0096.02	Bedrock	Sampler: Wilberg/...Stored: Løkken Comment: Fink. massiv py-min. 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

Deposit Area 3429 - 008 Elgsjøbekken

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#
ST0096.01	Bedrock	10	47	27	-1	12	-.3	28.0
ST0096.02	Bedrock	79	90	23	5	34	-.3	9.0

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Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	S%
ST0096.01	3.0	2.0	199	-.2	6	1.00	-3	12	47.80
ST0096.02	3.0	3.0	156	-.2	-1	1.00	-3	6	37.90

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Sample No.	V*	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*
ST0096.01	3	2	23	18.16	4.00	-8.00	-2	1.0	1.00
ST0096.02	7	3	111	24.50	6.00	-8.00	-2	4.0	2.00

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Sample No.	B*
ST0096.01	8
ST0096.02	9

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The fact sheet was created on 05.05.2024

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