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	THE ORE DATABASE
	Deposit Area 1635 - 025
	(Last updated 01.jul.1998)

Importance

Public:

Not Assessed (reg. 18.02.2015)

Economical:

Not classified/evaluated

Operations

	From - To	Activity	Comments
	1997 - 1997	Sampling	Company/Institution :NGU-Malmreg.

Mineralization

	Era:		Period:
	Dating:		Method:
	Genesis:	Sedex	Form:
	Main texture:	Banded	Min. distribution:	Semi-massive (20-50 % ore minerals)

Main grain size:

Fine grained (< 1 mm)

Main alteration:

	Strike/Dip:	355 / 65	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Period:

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

Group:

Støren

Formation:

Mineralogy

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

Lithology:

	Relationship	Rock	Origin
	Host rock	Black schist	Sedimentary Original rock :Bituminous silty mudstone
			Metamorphic facies :Greenschist
	Wall rock	Grey-green schist	Sedimentary Original rock :Tuffite
			Metamorphic facies :Greenschist

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Foliation	Strike/Dip :355 / 65	Post-mineralisation ;...Effect :None

Information(s) in free text format

Description

Mineraliseringen er undersøkt med en grunn, nå vannfylt synk (5 m3 tipp), som ligger ca. 250 m SØ for et lite tjern. 80 cm mektig svartskifer fører massiv til semimassiv magnetkis-svovelkis-mineralisering (prøve 01). I mineraliseringen opptrer to malmtyper: 1) En breksjert type, med finkornig svovelkis-grunnmasse med litt grøvre (stedvis krystaller opptil 5 mm), spredt svovelkis, og avrevne, "krøllete" svartskiferfragmenter ("twisted and ball" tekstur / durchbewegung). 2) Massiv til semimassiv, finbåndet (mm- til cm-skala) svovelkis-dominert, med enkelte, opptil 1 cm mektige bånd av massiv magnetkis (prøve 02). Mineraliseringens ligg utgjøres av et 30 cm mektig lag av lys feltspatisk skifer med sulfid-disseminasjon. Under denne og over den mineraliserte svartskiferen er det finkornig, siltig, grågrønn skifer. Mineraliseringen kan følges som ei rustsone i noen få blotninger 20 m mot nord og 60 m mot sør. Den skjæres av minst en trondhjemittgang.

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
	ST0089.01	Dump	Sampler :Wilberg/...Stored :Løkken Comment :Massiv po-py-min. med svartskiferfragmenter No. of registrated element analyses = 1
	ST0089.02	Dump	Sampler :Wilberg/...Stored :Løkken Comment :Massivpy(-po)-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 1635 - 025 Litlfjellet

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#
ST0089.01	Dump	432	889	58	34	156	.8	124.0
ST0089.02	Dump	155	488	66	38	95	.7	167.0

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Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	S%
ST0089.01	2.0	1.0	120	2.7	30	50.00	41	13	20.80
ST0089.02	4.0	9.0	360	1.4	10	7.00	59	9	34.40

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Sample No.	V*	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*
ST0089.01	40	9	494	32.18	12.00	8.00	-2	12.0	14.00
ST0089.02	17	12	235	27.57	9.00	8.00	4	8.0	7.00

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Sample No.	B*
ST0089.01	11
ST0089.02	7

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The fact sheet was created on 19.05.2024

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