English version
Prospekt 3047 - 022 Skuterud Nordgruver
(Objekt Id: 5903)
(Sist oppdatert: 16.03.2020)
Tilhører provinsen: Modum Vest

Fylke: Viken Kommune: Modum (3047)
Kart 1:50000: Hokksund (1714-1) Kart 1:250000: Skien
Koordinatsystem: EU89-UTM Zone 32
Øst: 548211 m. Nord: 6649252 m.
Lengdegrad: 9.8637970 Breddegrad: 59.9777870

Ressurstype: Jernlegeringsmetaller (Cr,Ni,Co,V,Mo,W) Ressursundertype: Kobolt
Element(er): Co Cu As
Råstoffbetydning: Ikke vurdert (reg. 09.02.2017)

Ressurser og produksjon
Aktivitet: Gruvedrift Reserver:
Driftsmetode: Dag- og underjordsdrift Historisk produksjon: 140 tusen tonn

Element/produkt Gehalt/Kvalitet Reg. dato
Co 0.2 % 31.08.2010

Genese: Form:
Hovedtekstur: Min. fordeling:
Kornstørrelse: Hovedomvandling:
Strøk/Fall: Retning:
Stratigrafisk klassifikasjon av vertsbergart
Æra: Periode:
Tektonisk complex:
Intrusivt komplex:
Gruppe: Formasjon:

Opplysning(er) i fritekstformat
Fri tekst
The cobalt ores at Skuterud were found in 1772, and ordinary production started in 1776. First in large open pits, but from 1827 until the closure in 1898, mining was done underground. In the 1890s, ore reserves decreased rapidly, leading to the final shutdown of mining operation in 1898. On the basis of different old mining reports the total production is estimated to 1 Mt with 0.2 % Co. In addition to cobalt, the ores contain significant grades of copper (up to 1-2 %) and locally enrichment of gold (several ppm). The cobalt occurrences at Modum are related to sulphide-rich schist zones, so-called fahlbands. The most extensive sulphide-rich zone has a length of 12 km along strike, and is up to 100–200 m wide. The rock type hosting the sulphides may be characterized as a quartz-plagioclase-tourmaline-phlogopite-sulphide gneiss or schist. Graphite is locally common and its content may attain more than 5 % of the rock. The cobalt mineralisation is, to a large degree, characterised by impregnation of cobaltite (CoAsS), glaucodote ((Co,Fe)AsS), safflorite ((Co,Fe)As2) and skutterudite (CoAs3), which partly occur as enriched in quartz-rich zones and lenses. The cobalt-rich lenses are structurally controlled, following axes of folds and lineations in the area.

Bilde(r) fra forekomstområdet:
Foto nr. 1 viser "Nordgruvene"
Foto nr. 2 viser "Erythrin"

Fra NGU's Referansearkiv.:
Grorud, Hans-Fredrik , 1997
Textural and compositional characteristics of cobalt ores from the Skuterud Mines of Modum, Norway
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.77 (1);31-38 sider
The metasedimentary rocks of the Modum Complex contain concordant, sulphide- rich zones, commonly referred to as 'fahlbands'. Two of these fahlbands contain cobalt minerals. Petrographic and microprobe analyses of the cobalt minerals have been performed on selected samples, to gain insight into the genesis and post-mineralization history of the cobalt minerals. It is suggested that these minerals precipitated from an oxidizing fluid, and that certain minerals in the uraninite.thorianite series precipitated simulataneously. The fahlband silicates, and later the cobalt minerals, were recrystallized during Sveco- norwegian penetrative deformation and thermal maximum (-1.2- -0.9Ga). Prolonged heating during this event eradicated any compositional zoning which may originally have been present. Neither textural nor mineral chemical analyses indicate whether the observed cobalt minerals are the result of a primary precipitation, or of remobilization.

Navn på lokalitet: Gruve 6
(Objekt Id: 32742 22,01,00)

Fylke: Viken Kommune: Modum (3047)
Kart 1:50000: Hokksund (1714-1) Kart 1:250000: Skien
Koordinatsystem: EU89-UTM Zone 32
Øst: 548292 m. Nord: 6649459 m.
Lengdegrad: 9.8652970 Breddegrad: 59.9796440

Ressurstype: Jernlegeringsmetaller (Cr,Ni,Co,V,Mo,W) Ressursundertype: Kobolt
Element(er): Co As

Faktaarket ble generert 20.09.2021

Spørsmål eller kommentarer vedrørende faktaarket kan mailes til:
Copyright © 2021 Norges geologiske undersøkelse