Norsk versjon
	THE ORE DATABASE
	Deposit 4227 - 037 Knaben I
	(Object Id: 5086) (Last updated: 18.03.2024)

Products

	Element/product	Crude ore grade or quality	Reg. date
	Mo	0.4 %	13.03.2024
	MoS2	0,4-0,8 %	19.01.2022

Operations

	From - To	Activity	Comments
	1885 - 1887	Test mining
	1894 - 1897	Test mining
	1901 - 1909	Regular production	Company/Institution :Blackwells Develop. Corp. Ltd. Liverpool
			Det engelske selskapet tok over fra norsk-svenske eiere i 1908
	1913 - 1919	Regular production	Company/Institution :Cammel, Laird & Co., Sheffield
			Fra 1918 A/S Knaben Molybdæn Gruber
	1934 - 1939	Regular production	Company/Institution :1918 A/S Knaben Molybdæn Gruber

Mineralization

	Era:	Proterozoic	Period:	Neoproterozoic
	Genesis:	Shear zone formation	Form:	Lens
	Main texture:	Structureless	Min. distribution:	Irregular (scattered)

Main grain size:

Medium grained (1-3 mm)

Main alteration:

	Strike/Dip:	0 / 30	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Proterozoic

Period:

Mesoproterozoic

	Province:	South Norwegian Basement Province
	Geotec.unit:	Agder Complex
	Tectonic complex:
	Igneous complex:

Group:

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Feldspar	Major mineral (>10%)
	Gangue mineral	Biotite	Subordinate mineral (1-10%)
	Gangue mineral	Zircon	Accessory mineral (<1%)
	Ore mineral	Molybdenite	Major mineral (>10%)
	Ore mineral	Pyrite	Subordinate mineral (1-10%)

Lithology:

	Relationship	Rock	Origin
	Host rock	Flaser gneiss	Intrusive Original rock :Granite
			Metamorphic facies :Amphibolite
	Wall rock	Amphibolite	Intrusive
			Metamorphic facies :Amphibolite

Information(s) in free text format

Free text

Knaben I is the oldest mine in the Knaben area. The molybdenite mineralisation is assumed to have been found in around 1730, and in 1885 the first primitive test mining started at “Blyantberget” (“Pencil mountain”). The deposit was intermittently mined by various companies until all activity ceased in 1939. It is assumed that about 128.000 tonnes of crude ore have been mined and yielded 570 tonnes of contained 100 % MoS2 (Bugge 1963, Eriksson 1970). A characteristic feature of the Knaben I deposit are meter-scale xenoliths of amphibolite and granitic flaser gneiss (tiger-striped gneiss) within porphyritc granitic gneiss. The coarse-grained molybdenite mineralization is bound to sub-horizontal pegmatitic quartz bands and veins (0.5 to 30 cm thick, several meters in lateral extension) hosted by the flaser gneiss. The quartz bands occasionally grade into aplitic feldspar bands with coarse-grained molybdenite. The quartz bands crosscut the foliation of the flaser gneiss with low angle of 5 to 10° (Müller et al. 2015). Minor amounts of chalcopyrite and pyrite are associated the molybdenite mineralisation, and two samples yield high values of zirconium (> 500 ppm) and other incompatible elements.

Bibliography:

From NGU's Reference Archive:

Bugge, Arne , 1963

	Norges molybdenforekomster.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.217;1-134 pages

Abstract:

The ore fields and individual deposits which are mentioned in the text are shown on the map, figure 2. For those areas where the deposits lie so close together that they cannot be shown separately on this map, detail maps have been drawn on larger scales. In the descriptions there will also be found special maps covering the most important molybdenum areas. An index of the deposits which are mentioned is arranged both alphabetically and according to the numbers on the map. The majority, including the most important, of the ore deposits in Southern Norway lie within a marked zone, which is shown on the map, figure 3. At varying periods of time different metals have characterised the long zone of ore deposits: titanium in the southwest, then molybdenum in the area from Gursli to Knaben, copper and molybdenum in Telemark, silver, zinc and lead from Kongsberg eastwards, and further to the east, molybdenum again. From the map, figure 4, it can be seen that the most important groups of deposits are situated to both sides of the granite-gneiss area of the mountanious region of Southern Norway and that they lie in migmatised gneisses along the southwest side and in the schists and quartzites of the Telemark supracrustal suite along the northeast side.

Müller, Axel; Henderson, Iain; Jourdan, Charles; Slagstad, Trond , 2016

	Mineralization styles and formation temperatures of the Knaben molybdenum deposits, southern Norway

;Norges geologiske undersøkelse;RAPPORT;NGU-rapport; No.2015.030;59 pages

Abstract:

The report documents the lithologies and molybdenite mineralization exposed in underground mines of the Knaben molybdenum (Mo) mining district in Kvinesdal, Vest-Agder, SW Norway. Scanning electron microscope cathodoluminescence (SEM-CL) and trace element analyses of quartz by laser ablation inductively coupled mass Spectrometry (LA-ICP-MS) were performed on 37 quartz and quartz-bearing samples in order to better understand the P-T conditions during magma emplacement and Mo-mineralization.

Holmsen, T. W. , 1961

	Rapport over molybdenglansforekomster i Vestlandske distrikt i området Vest-Agder fylke samt herredene Lund og Sokndal i Rogaland.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 7513;178 pages

Abstract:

Rapporten er ordnet i tre deler. Del 1 gir oversikt over alle mutede skjerp i området (side 4-106). Del 2 gir driftsberetninger hentet fra Norges Bergverksdrift for de skjerp hvor det har vært undersøkelsesarbeid eller regulær drift (side 107-135). Del 3 gir tittel med korte sammendrag av rapporter fra de aktuelle steder som er beskrevet (side 136-158). Side 158-176 består av kartbilag i M 1:50 000. Tittel forts.: ... Rogaland fylke.

References not to be found in NGU's Reference Archive.:

Gvein, Ø., Mørk, K. & Sverdrup, T.L. 1979: The Molybdenite-province of southwestern Norway. BV rapport 1038, 73p.

Eriksson, W. 1970. Sammanställda beskrivningen över Knaben "Avesta IV A/S Knaben Molybdaengruber, Norge". BV Rapport 3965, 100 s.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	JS-W2124	Dump	Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2 Comment: Molybdenite aggregates and sulphide-bands smokey-quartz No. of registrated element analyses = 1
	JS-W2125	Dump	Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2 Comment: Molybdenite strong dissemination/bands in biotitt-rich rock 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 4227 - 037 Knaben I

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#
JS-W2124	Dump	105	85	8	3	4	.3	-1.0
JS-W2125	Dump	74	482	10	12	6	.2	-1.0

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Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sn*	Sb*	Bi*
JS-W2124	8.0	4.0	1	.0	70	51000.00	2	0	0
JS-W2125	-5.0	5.0	1	.6	430	40100.00	5	0	0

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Sample No.	Se*	Ga*	Ge*	In*	S%	V*	Cr*	Mn*	Fe%
JS-W2124	17.00	8.31	0.72	0.14	3.60	53	11	410	2.46
JS-W2125	14.00	22.20	0.71	0.31	2.97	92	8	1305	8.06

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Sample No.	Th*	U*	W*	Rb*	Sr*	Y*	Zr*	Nb*	Ta*
JS-W2124	113.50	6.40	22	92.0	4.9	70.4	500	44.70	2.31
JS-W2125	101.00	10.70	13	489.0	8.8	60.1	500	99.40	4.09

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Sample No.	Cs*	La*	Ce*	Li*	Be*	Na*	Mg*	Al*	P*
JS-W2124	2.65	403.00	500.00	25	1	300	2800	6400	610
JS-W2125	9.00	377.00	500.00	155	1	200	15200	24900	450

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Sample No.	K *	Ca*	Sc*	Ti*	Te*	Hf*	Re*	Tl*
JS-W2124	5100	1800	7.00	4430	2.05	26.90	2	1
JS-W2125	26100	2000	26.40	12400	1.37	66.60	2	4

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The fact sheet was created on 06.05.2024

Questions or comments regarding the fact sheet can be emailed to: ressursdatabaser@ngu.no

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