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THE ORE DATABASE
Deposit 3316 - 021 Skuterud Mellomgruver
(Object Id: 5902)
(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: 548248 m. North: 6648836 m.
Longitude: 9.8643630 Latitude: 59.9740530
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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. 20.05.2019)

Resources and production
Activity: Mining Reserves:
Operating method: Open pit and underground mining Historical production: 574 thousand tons


Products
Element/product Crude ore grade or quality Reg. date
Co 0.2 % 31.08.2010

Operations
From - To Activity Comments
1773 - 1776 Test mining Company/Institution :Blaafarveværket
1776 - 1898 Regular production Company/Institution :Blaafarveværket

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.

Fieldsamples
Sample No. Sample type Miscellanrous
BU0096.01 Dump
Sampler: T. Bjerkgård/I. Henderson/...Stored: Løkken/...Size(kg): 3
Comment: Rich impregnation of chalcopyrite with lesser pyrrhotite, accessory cobalt minerals and molybdenite, in gedrite/anthophyllite rock with some quartz and biotite.
No. of registrated element analyses = 1
BU0096.02 Dump
Sampler: T. Bjerkgård/I. Henderson/...Stored: Løkken/...Size(kg): 3
Comment: Pyrrhotite-chalcopyrite impregnation in biotite-bearing quartz-sericite schist with porphyroblasts of sillimanite
No. of registrated element analyses = 1
BU0096.03 Bedrock
Sampler: T. Bjerkgård
Comment: Co mineralisation in quartzitic rock, The Clara adit
No. of registrated element analyses = 1
BU0096.04 Bedrock
Sampler: T. Bjerkgård
Comment: Co mineralization in chlorite-rich quartzitic rock
No. of registrated element analyses = 1
BU0096.05 Bedrock
Sampler: T. Bjerkgård
Comment: Co mineralization in quartzitic rock (below open pit)
No. of registrated element analyses = 1
BU0096.06 Bedrock
Sampler: T. Bjerkgård
Comment: Co mineralised chlorite-biotite schist
No. of registrated element analyses = 1
BU0096.07 Bedrock
Sampler: T. Bjerkgård
Comment: Co mineralisation in dark chlorite-biotite schist (from location Hvalfisken)
No. of registrated element analyses = 1
BU0096.08 Bedrock
Sampler: T. Bjerkgård
Comment: Co mineralised grey, spotty rock (location Hvalfisken)
No. of registrated element analyses = 1
CONSTANTIN-Ø Bedrock
Sampler: T. Bjerkgård
Comment: Coablt mineralised schist
No. of registrated element analyses = 1
HVALFISKEN 1 Bedrock
Sampler: T. Bjerkgård
Comment: Cobalt-rich schist
No. of registrated element analyses = 1
HVALFISKEN 2 Bedrock
Sampler: T. Bjerkgård
Comment: Cobalt-rich schist
No. of registrated element analyses = 1
SKUTERUD-MG1 Bedrock
Sampler: T. Bjerkgård
Comment: Cobalt-rich schist
No. of registrated element analyses = 1
77419 Bedrock
Sampler: T. Bjerkgård
Comment: Cobalt-mineralised schist
No. of registrated element analyses = 1
77421 Bedrock
Sampler: T. Bjerkgård
Comment: Cobalt in schist
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Clara stoll
(Object Id: 32736 21,01,00)
Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548453 m. North: 6648633 m.
Longitude: 9.8679870 Latitude: 59.9722010
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Forhaapningsstoll
(Object Id: 32737 21,02,00)
Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548300 m. North: 6648637 m.
Longitude: 9.8652300 Latitude: 59.9722550
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Dagåpning
(Object Id: 32738 21,03,00)
Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548243 m. North: 6648606 m.
Longitude: 9.8642020 Latitude: 59.9719830
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Stoll
(Object Id: 32739 21,04,00)
Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548303 m. North: 6648759 m.
Longitude: 9.8653300 Latitude: 59.9733580
Show on map
Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Dagåpning
(Object Id: 32740 21,05,00)
Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548247 m. North: 6649000 m.
Longitude: 9.8643830 Latitude: 59.9755200
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Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Name of Locality: Ludvig Eugen stoll
(Object Id: 32741 21,06,00)
Location
County: Buskerud Municipality: Modum (3316)
Map 1:50000: Hokksund (1714-1) Map 1:250000: Skien
Coordinate system: EU89-UTM Zone 32
East: 548708 m. North: 6648802 m.
Longitude: 9.8725940 Latitude: 59.9736880
Show on map
Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Cobalt
Element(s): Co As


Analyse Results
from
Deposit Area 3316 - 021 Skuterud Mellomgruver

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#
BU0096.01 Dump 34397 34 2 929 105 .5 2266.0
BU0096.02 Dump 6150 3 4 195 189 .2 132.0
BU0096.03 Bedrock 1695 -10 10 742 69 -1.0 105.0
BU0096.04 Bedrock 1640 -10 -10 145 24 -1.0 7.0
BU0096.05 Bedrock 176 -10 -10 37500 926 -1.0 236.0
BU0096.06 Bedrock -5 -10 -10 2010 103 -1.0 4.0
BU0096.07 Bedrock 165 20 -10 1450 150 -1.0 3.0
BU0096.08 Bedrock 1845 -10 10 1330 210 -1.0 39.0
CONSTANTIN-Ø Bedrock 736 22 7 8170 224 .2 150.0
HVALFISKEN 1 Bedrock 358 29 16 10000 1380 .2 351.0
HVALFISKEN 2 Bedrock 221 118 31 10000 1190 .3 116.0
SKUTERUD-MG1 Bedrock 3900 63 18 10000 845 .2 98.0
77419 Bedrock 7420 23 30 1845 158 .7 294.0
77421 Bedrock 5950 12 6 1560 108 .2 118.0
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sn* Sb* Bi*
BU0096.01 1.0 1.0 6 .1 1 9.00 2 8
BU0096.02 1.0 1.0 34 .1 12 16.00 2 2
BU0096.03 2120 -5.0 -50 12.00 -10 -10
BU0096.04 90 -5.0 -50 -5.00 -10 10
BU0096.05 53800 -5.0 50 13.00 -10 -10
BU0096.06 1750 -5.0 110 -5.00 -10 -10
BU0096.07 1230 -5.0 -50 18.00 -10 -10
BU0096.08 19900 -5.0 -50 -5.00 -10 -10
CONSTANTIN-Ø 9110 -.1 50 20.00 -1 -1 -1
HVALFISKEN 1 61400 .3 70 10.00 -1 1 -1
HVALFISKEN 2 40900 .5 30 4.00 -1 -1 -1
SKUTERUD-MG1 5930 .3 30 137.00 -1 -1 -1
77419 3170 .2 60 17.00 1 -1 1
77421 2440 -.1 110 7.00 -1 -1 -1
------------------
Sample No. Se* Ga* Ge* In* S% V* Cr* Mn* Fe%
BU0096.01 3.63 1 23 67 5.56
BU0096.02 2.83 50 76 60 4.19
BU0096.03 .80 62 200 110 2.40
BU0096.04 1.20 25 234 100 2.65
BU0096.05 2.38 28 100 180 2.52
BU0096.06 .12 232 136 300 8.47
BU0096.07 .26 193 110 240 9.38
BU0096.08 1.65 30 244 70 2.85
CONSTANTIN-Ø -1.00 11.00 -1.00 -1.00 61 274 160 4.25
HVALFISKEN 1 5.00 9.00 -1.00 -1.00 47 227 109 4.01
HVALFISKEN 2 4.00 10.00 -1.00 -1.00 63 327 148 3.40
SKUTERUD-MG1 13.00 13.00 -1.00 -1.00 70 123 151 18.10
77419 3.00 15.00 -1.00 -1.00 53 220 143 8.53
77421 4.00 12.00 -1.00 -1.00 111 233 83 3.34
------------------
Sample No. Th* U* W* Sr* La* B* P* Sc* Ti*
BU0096.01 1.00 4.00 1 2.0 1.00 4
BU0096.02 5.00 4.00 1 3.0 18.00 5
BU0096.03 5.00 -500
BU0096.04 -5.00 1000
BU0096.05 -5.00 2300
BU0096.06 20.00 8300
BU0096.07 9.00 1700
BU0096.08 -5.00 -500
CONSTANTIN-Ø 8.00 10.00 -1 60 9.00 3210
HVALFISKEN 1 6.00 3.00 -1 140 9.00 2610
HVALFISKEN 2 6.00 9.00 -1 70 9.00 3650
SKUTERUD-MG1 5.00 36.00 -1 90 9.00 2960
77419 13.00 116.00 -1 210 8.00 4210
77421 8.00 7.00 1 2000 10.00 2440
------------------
Sample No. Te* Hf*
BU0096.01
BU0096.02
BU0096.03
BU0096.04
BU0096.05
BU0096.06
BU0096.07
BU0096.08
CONSTANTIN-Ø -1.00 8.00
HVALFISKEN 1 1.00 6.00
HVALFISKEN 2 1.00 8.00
SKUTERUD-MG1 2.00 8.00
77419 -1.00 9.00
77421 -1.00 3.00

The fact sheet was created on 24.04.2024
Questions or comments regarding the fact sheet can be emailed to:
ressursdatabaser@ngu.no
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