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Prospect 3316 - 017 Skuterud Sørgruver
(Object Id: 5898)
(Last updated: 16.03.2020)
Belongs to the Province: Modum Vest

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548320 m. North: 6648149 m.
Longitude: 9.8654780 Latitude: 59.9678750
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co Cu As
Importance
Raw material meaning: Not Assessed (reg. 09.02.2017)
Historical: Yes , (Confirmed 16.feb.2005 by Havard Gautneb)

Resources and production
Activity: Mining Reserves:
Operating method: Open pit and underground mining Historical production: 280 thousand tons


Mineralization
Genesis: Form:
Main texture: Min. distribution:
Main grain size: Main alteration:
Strike/Dip: Direction:
Plunge:
Stratigraphic classification of host rock
Era: Period:
Province:
Geotec.unit:
Tectonic complex:
Igneous complex:
Group: Formation:

Information(s) in free text format
Free text
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.

Bibliography:
From NGU's Reference Archive:
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 pages
Abstract:
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.

Name of Locality: Open pit
(Object Id: 32720 17,01,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548380 m. North: 6648105 m.
Longitude: 9.8665380 Latitude: 59.9674690
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Open pit
(Object Id: 32721 17,02,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548315 m. North: 6648003 m.
Longitude: 9.8653680 Latitude: 59.9665690
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Benneche stoll
(Object Id: 32722 17,03,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548433 m. North: 6647926 m.
Longitude: 9.8674630 Latitude: 59.9658640
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Muggerud skjerp
(Object Id: 32723 17,04,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548428 m. North: 6647816 m.
Longitude: 9.8673300 Latitude: 59.9648770
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Fortuna stoll
(Object Id: 32732 17,05,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548368 m. North: 6648290 m.
Longitude: 9.8663670 Latitude: 59.9691400
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Fortuna gruver
(Object Id: 32734 17,06,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548314 m. North: 6648360 m.
Longitude: 9.8654160 Latitude: 59.9697660
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Henriette gruver
(Object Id: 32735 17,07,00)

Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548271 m. North: 6648467 m.
Longitude: 9.8646710 Latitude: 59.9707320
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


The fact sheet was created on 28.03.2024

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