Norsk versjon
	THE ORE DATABASE
	Occurence 4034 - 002 Nordaberg
	(Object Id: 5495) (Last updated: 28.03.2020)

Products

	Element/product	Crude ore grade or quality	Reg. date
	Mo	4 %	13.12.2007

Operations

	From - To	Activity	Comments
	1914 - 1915	Regular production	Company/Institution :Christiania Minekompani

Mineralization

	Era:	Proterozoic	Period:	Neoproterozoic
	Genesis:	Hydrothermal vein	Form:	Lens
	Main texture:	Fracture filling	Min. distribution:	Irregular (scattered)

Main grain size:

Medium grained (1-3 mm)

Main alteration:

	Strike/Dip:	25 / 90	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Proterozoic

Period:

Mesoproterozoic

	Province:	South Norwegian Basement Province
	Geotec.unit:	Telemark Supergroup
	Tectonic complex:
	Igneous complex:

Group:

Bandak Group

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Actinolite	Subordinate mineral (1-10%)
	Gangue mineral	Calcite	Subordinate mineral (1-10%)
	Gangue mineral	Chlorite	Subordinate mineral (1-10%)
	Ore mineral	Molybdenite	Major mineral (>10%)
	Ore mineral	Malachite	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Wall rock	Metasandstone	Sedimentary Original rock :Sandstone

Information(s) in free text format

Free text

Nordaberg molybdenskjerp ligger i sørsiden av en ås om lag 600 m vest for gården Nordaberg ved Høydalsmo. Forekomsten ble funnet i 1885. Christiania Minekompani drev sommeren 1914 med 3-4 mann ut ca. 100 kbm som gav 20-25 tonn råmalm med 4% MoS2. En del av malmen ble eksportert, en del ble forsøkt anriket, noe som gav 363 kg med gjennomsnittlig 62,5% MoS2. Sommeren 1915 ble det produsert 77 kg anriket malm med 75% MoS2. Skjerpet består av en ca. 25 m lang skjæring i NNØ-SSV retning. Bredden varierer fra 1-1.5 m, mens dybden er 6-7 m lengst sør. Tipphaugen på sørsiden av skjæringen anslås til ca. 200 kbm. Like nordvest for skjæringen (ca. 10 m) er det en grunn røsk/skjæring, ca. 7-8 m lang og 1-2 m dyp. Den går noenlunde parallell med hovedskjæringen. Det er også en liten røsk 60 m nord for hovedskjæringen langs strøket. Driften har foregått langs steiltstående 10-20 cm tykke kvartsganger i en skifrig metasandstein. Gangene fører spredte korn og belegg av molybdenglans. Ikke noe var synlig nå under befaring, bortsett fra små mineraliserte kvartsblokker på tipphaugen. Blokkene inneholdt spredt impregnasjon av opptil 5 mm korn av molybdenglans i kvarts med litt kalkspat. Impregnasjonen var anriket i opptil cm-tykke årer/slirer. Ellers var litt malakitt, aktinolitt og kloritt tilstede i enkelte blokker.

Bibliography:

From NGU's Reference Archive:

Bryn, T. , 1940

	Rapport over befaring av Nordaberg, Høydalsmo og Hustøl molybdengrube, Fyresdal.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 3324;2 pages

	Abstract:
	Nordalberg grube: Malmen er striper av molybdenglans langs tynne kvartsårer i skifer. Den interessante malmen er tatt ut: dagskjerping. Hustøl grube: Molybdenglans finnes langs sideflatee og i sprekker i en kvartsgang som er 0,4 til 1,0 m tykk. Spredte blotninger av gangene antyder at den kan følges ca 700 m langs strøket. Forf. konkluderer malmen ikke er drivverdig.

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.

Dons, Johannes A. , 1963

	De prekambriske bergarter i Telemark, I. Gruber og skjerp innen gradeteigkart E36V Kviteseid.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.216;1-80 pages

Abstract:

Approximately 115 mines and claims have been examined in the years 1941-1961 during regional geological mapping of the Kviteseid quadrangle. The map area covers a part of the "Thelemark-Sætersdal ore province" established by prof. J.H.L. Vogt in 1886. The oldest mine in the area, opened in the year 1524, was worked for silver bearing chalcopyrite and bornite. Other mines have been worked for gold, native copper and silver, molybdenite, galena, arsenopyrite, bismuthinite. All the mines have long since been abandoned and most of the surface workings are overgrown and difficult to find. The 15 native copper and silver deposits (which also contain vanadium minerals) form a separate group. They are all situated along the contact between a sandstone and an overlying basalt, the ore being confined to the sandstone. Most of the other deposits are of Quartz vein type. In quartzites which cover the greatest part of the map area, most of the quartz veins are barren. The great abundance of ore minerals in quartz veins in basic lavas and basic sills may be due to favourable pH conditions in these rocks. The galena deposits are found within a limited area close to a penetrating granite. The ore mineral paragenese in some of the deposits may have been formed under hypothermal to mesothermal conditions whereas other possibly originated at lower temperatures.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	TE0109.01	Dump	Sampler: Terje Bjerkgård Comment: Kvartsåre med tynne årer og impregnasjon av molybdenglans, noe malakitt No. of registrated element analyses = 1
	TE0109.02	Dump	Sampler: Terje Bjerkgård Comment: Kvartsåre med tynne årer og spredt impregnasjon av molybdenglans 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 4034 - 002 Nordaberg

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#
TE0109.01	Dump	470	-100	100	-10	-10	-2.0	-10.0
TE0109.02	Dump	1530	-100	-100	-10	-10	4.0	-10.0

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Sample No.	Pt#	Pd#	As*	Cd*	Mo*	Sb*	Bi*	Cr*	Mn*
TE0109.01	-10.0	-10.0	-100	-10.0	4680.00	30	-100	10	200
TE0109.02	-10.0	-10.0	-100	-10.0	1360.00	30	-100	-10	300

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Sample No.	Fe%	W*	Sr*	Na*	Mg*	Al*	P*	Ca*	Hg*
TE0109.01	.52	-10	10.0	100	1000	1500	70	5300	-10
TE0109.02	.51	610	20.0	100	1400	2100	130	6200	-10

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The fact sheet was created on 24.04.2024

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