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THE ORE DATABASE
Prospect 1833 - 098 Heramb gruve
(Object Id: 2833)
(Last updated: 22.03.2024)
Belongs to the Province: Mofjellet sink-bly
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Storforshei (2027-4) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 469944 m. North: 7350509 m.
Longitude: 14.3306040 Latitude: 66.2730780
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Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Cu Kis
Importance
Raw material meaning: Not Assessed (reg. 09.02.2017)

Resources and production
Activity: Test mining Reserves:
Operating method: Underground mining Historical production: ,4 thousand tons


Products
Element/product Crude ore grade or quality Reg. date
Ag 45 ppm 24.03.1992
Cu 3 % 24.03.1992
Pb 0.2 % 22.03.2024
Zn 3 % 24.03.1992

Operations
From - To Activity Comments
1910 - 1911 Test mining
1965 - 1965 Geology
1968 - 1968 Geology
1976 - 1976 Geophysics
1980 - 1981 Geology
1982 - 1982 Core drilling
1984 - 1984 Geophysics Company/Institution :NGU
2007 - 2007 Geophysics Company/Institution :GEXCO Norge AS
TEM (by SkyTEM)
2008 - 2008 Core drilling Company/Institution :GEXCO Norge AS
Two holes to investigate deep geophysical anomaly (not found)
2008 - 2009 Geology Company/Institution :NGU

Mineralization
Era: Proterozoic Period: Neoproterozoic
Genesis: Volcex Form: Lens
Main texture: Cataclastic Min. distribution: Massive (>50 % ore minerals)
Main grain size: Medium grained (1-3 mm) Main alteration:
Strike/Dip: 245 / 35 Direction: 270
Plunge: 15
Stratigraphic classification of host rock
Era: Proterozoic Period: Neoproterozoic
Province: Caledonides
Geotec.unit: Rødingsfjell Nappe Complex
Tectonic complex: Uppermost Allochthon
Igneous complex:
Group: Mofjell Group Formation:

Mineralogy
Relationship Mineral Amount
Gangue mineral Muscovite Major mineral (>10%)
Gangue mineral Plagioclase Major mineral (>10%)
Gangue mineral Potassic feldspar Major mineral (>10%)
Gangue mineral Quartz Major mineral (>10%)
Ore mineral Pyrrhotite Major mineral (>10%)
Ore mineral Pyrite Subordinate mineral (1-10%)
Ore mineral Chalcopyrite Subordinate mineral (1-10%)
Ore mineral Sphalerite Subordinate mineral (1-10%)
Ore mineral Rutile Accessory mineral (<1%)
Ore mineral Fahlore Accessory mineral (<1%)
Ore mineral Molybdenite Accessory mineral (<1%)
Ore mineral Galena Accessory mineral (<1%)
Ore mineral Marcasite Accessory mineral (<1%)
Ore mineral Arsenopyrite Accessory mineral (<1%)
Ore mineral Limonite Accessory mineral (<1%)

Lithology:
Relationship Rock Origin
Host rock Muskovittgneis Extrusive
Original rock :Tuff
Metamorphic facies :Amphibolite
Wall rock Lys glimmergneis Sedimentary
Original rock :Greywacke
Metamorphic facies :Amphibolite

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :245 / 35 Post-mineralisation ;...Effect :None
Host rock Mineral lineation Strike/Dip :270 / 15 Post-mineralisation ;...Effect :Controls
Host rock Fold axis Strike/Dip :270 / 15 Post-mineralisation ;...Effect :Controls

Information(s) in free text format
Free text
The Heramb and Bertelberget deposits are the easternmost in the Raudvatnet zone of pyritiferous mica schist. They are c. 2 km apart, but may somehow be connected according to the regional geophysical data, including TURAM (Dalsegg, 84) and the 2007 TEM data by GEXCO. The geology in the area is characterized by several alternating thin layers of amphibolite, biotite gneiss and muscovite gneiss, separated by thicker units of grey gneiss. The latter is often quite homogeneous and massive (e.g. close to and to the west of Heramb, and is probably mainly of volcanic/intrusive origin (rhyolite/rhyodacite). The Heramb mineralization is characterized by massive sulfide veins carrying pyrrhotite and variable amounts of pyrite, chalcopyrite and sphalerite . There are also some veins strongly enriched in coarse-grained galena. An average of 14 samples from the dump yielded 3.7 % Cu, 3.1 % Zn, 0.2 % Pb, 45 g/t Ag and 0.45 g/t Au. Test mining was carried out at Heramb in 1910 and 1911, and an adit c. 50 m long was mined. This resulted in production of 193 tons with 2.87 % Cu, 4.80 % Zn. The ore zone in the adit had a thickness of 1-2 m over the first 36 m and varied from being very copper-rich to zinc-rich. In the last 14 meters of the adit only thin veins of mineralization were encountered. According to Krefting (1911) the average of the ore over a length of 36 m was 1.2 m with 1.9 % Cu and 3.4 % Zn. In 1982 eight holes were drilled around the Heramb deposit to investigate the continuation of the sulfide-rich veins towards depth. Only three of the holes intersected partly rich sulfide veins, and restricted partly the extent of the mineralization to the north and south. The best intersections were 1.75 m at 1.8 % Cu, 4 % Zn, 20 g/t Ag (bh8208) and 5.7 m at 1.5 % Cu, 0.9 % Zn, 25 g/t Ag (including 1.2 m at 4.8 % Cu, 0.9 % Zn, 73 g/t Ag¸ bh8209). A very strong geophysical anomaly (TEM and TURAM) c. 200 m to the north of the deposit was the target for drilling in 2008 (bh4608, bh4708), but no mineralization was found. The reason for this anomaly remains unknown.

Bibliography:
From NGU's Reference Archive:
Bjerkgård, Terje ; Marker, Mogens ; Slagstad, Trond ; Solli, Arne , 2008
Mofjell-prosjektet. Statusrapport 2008
;Norges geologiske undersøkelse;RAPPORT;NGU-rapport; No.2008.088;25 s. pages
Abstract:
Rapporten gir en status for Mofjellprosjektet, et 4-årig samarbeidsprosjekt mellom GEXCO Norge AS og NGU. Prosjektområdet er øst og sør for Mo i Rana, et område som kan inneholde økonomiske sulfidforekomster med Cu, Zn, Pb, Ag og Au. Målet er å få fram dette potensialet gjennom å kartlegge berggrunnen, de kjente og delvis drevne sulfidforekomstene og andre mineraliseringer i området. Berggrunnskartleggingen i 2008 har fokusert på den østlige delen av området, som omfatter fortsettelsen av Plurdalgruppen sørover og relasjonen til bergartsgrupper i øst. Dette innbefatter den viktige tidlig Kaledonske skyvestrukturen som kalles Langfjellsonen, som kan representere et malmgeologisk provinsielt skille, med jernmalmene i nord og sulfidforekomstene i sør. Under feltarbeidet ble det systematisk innsamlet 95 bergartsprøver til geokjemi, geokronologi og petrologi for å undersøke bergartenes dannelse som bakgrunn for relasjonen til malmgenese. Malmgeologiarbeidet har i 2008 fokusert på å skaffe oversikt over sulfidforekomster i Mofjellgruppen og en rekke nøkkelforekomster i de forskjellige mineraliserte sonene er kartlagt og prøvetatt. I tillegg har GEXCO innsamlet mange prøver, dels i form av håndstykkeprøver og dels i form av boring med packsack utstyr. Sammen med resultater fra GEXCOs diamantboringer viser arbeidet så langt at en rekke forekomster og soner i området kan være av økonomisk interesse og bør følges opp videre. De mest interessante områdene og forekomstene i Mofjellgruppen som peker seg ut så langt i tillegg til forekomstene i Mofjellet og Sølvberget er Hellerfjellet, Hesjelia-Hammertjønna, Heramb-Bertelberget og Småvatnan. Mer arbeid med dataene, blant annet sammenholdt med data fra tidligere prospekteringsaktivitet i området, er nødvendig for å komme nærmere inn på potensialet i både de ovenfor nevnte forekomstene og andre i området.

Bjerkgård, Terje ; Slagstad, Trond ; Solli, Arne ; Marker, Mogens , 2009
Mofjell-prosjektet: Statusrapport pr. juni 2009
;Norges geologiske undersøkelse;RAPPORT;NGU-rapport; No.2009.038;31 s. pages
Abstract:
I alt ble 95 bergartsprøver innsamlet under feltarbeidet i 2008; av disse 81 prøver for geokjemi og 26 prøver for mineralseparasjon og aldersbestesmmelse (de fleste av disse også for geokjemi). Geokjemi av både amfibolitter og felsiske metavulkanitter i Mofjellgruppen viser øybuesignatur. Resultatene er således i stor grad i overensstemmelse med det som tidligere er publisert. En god del av de grå gneisene ser ut til å representere felsiske metavulkanitter, noe som betyr at det er et større innslag av vulkanske bergarter i området enn tidligere antatt. Dette kan også være en av grunnene til at området er anomalt når det gjelder gull-innhold. Det blir viktig å identifisere de tykkere enhetene med grå gneis. Dersom disse er vulkanske, kan de ha vært viktige som både varme- og metallkilde for dannelse av sulfidforekomstene.

Bjerkgård, Terje; Marker, Mogens; Slagstad, Trond; Solli, Arne , 2013
The Mofjell project: summary and conclusions
;Norges geologiske undersøkelse;RAPPORT;NGU-rapport; No.2013.048;87 pages
Abstract:
The Mofjell project commenced in 2008 as a cooperation between GEXCO Norge AS, the county administration of Nordland and NGU. As GEXCO faced financial difficulties the external funding ended in 2009. The project area included Mofjellet and the eastern part of Plurdalen, an area with a large potential for economic sulfide deposits with Zn, Cu, Pb, Ag and Au. NGU has focused on establishing the geological setting of the Mofjell Group and its relation to ore formation. Another very important goal has been to assess the potential for economic ore deposits in the area, including enrichment of precious metals. On the basis of lithological observations and geochemistry, the Mofjell Group consists of a largely bimodal volcanic-sedimentary assemblage formed in an island-arc to back-arc setting. The data also show that the proportion of felsic volcanic rocks is much higher than previously described. A bimodal volcanic suite mixed with sediments is a geological environment which is regarded as favorable for both rich and large sulfide deposits.

Fieldsamples
Sample No. Sample type Miscellanrous
HERAMB-01 Dump
Sampler: T. Bjerkgård
Comment: Massive po-py-cpy ore
No. of registrated element analyses = 1
HE-01 Dump
Sampler: T. Bjerkgård
Comment: Massive py-po-sl-cpy ore
No. of registrated element analyses = 1
HE-02 Dump
Sampler: T. Bjerkgård
Comment: Massive py-po-sl-cpy ore
No. of registrated element analyses = 1
HE-03 Dump
Sampler: T. Bjerkgård
Comment: Massive py-po-sl-cpy ore
No. of registrated element analyses = 1
NO0725.01 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Muskovittgneis med py-po-diss. Bh. 8209 (2,70-3,10m).
No. of registrated element analyses = 1
NO0725.02 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Massiv po-cpy-sl-malm. Bh. 8209 (3,10-3,35m).
No. of registrated element analyses = 1
NO0725.03 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Muskovittgneis med py-diss. Bh. 8209 (3,35-3,90m).
No. of registrated element analyses = 1
NO0725.04 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Massiv py-po-sl-malm. Bh. 8209 (3,90-4,65m).
No. of registrated element analyses = 1
NO0725.05 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Muskovittgneis. Bh. 8209 (4,65-6,80m).
No. of registrated element analyses = 1
NO0725.06 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Massiv py-sl-po-malm. Bh. 8209 (6,80-6,95m).
No. of registrated element analyses = 1
NO0725.07 Core
Sampler: Wilberg, R./...Stored: Løkken
Comment: Muskovittgneis. Bh. 8209 (6,95-8,00m).
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Skjerp 1
(Object Id: 3548 98,01,00)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Storforshei (2027-4) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 469992 m. North: 7350637 m.
Longitude: 14.3316570 Latitude: 66.2742330
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Information(s) in free text format
Free text
Skjerp 1: Sprengt ut 0.5 m3 i granatglimmerskifer med enkelte mm-mektige kobberkis- og sinkblendeårer.

Name of Locality: Skjerp 2
(Object Id: 3549 98,02,00)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Storforshei (2027-4) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 469176 m. North: 7350677 m.
Longitude: 14.3134630 Latitude: 66.2745100
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Information(s) in free text format
Free text
Skjerp 2: Lite skjerp i glimmergneis med magnetkis.

Analyse Results
from
Deposit Area 1833 - 098 Heramb gruve

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#
HERAMB-01 Dump 153500 85100 289 1 -5 27.0 1010.0
HE-01 Dump 4080 114500 189 2 -5 4.0 80.0
HE-02 Dump 84900 47200 504 1 -5 27.0 1850.0
HE-03 Dump 8430 74000 143 2 -5 11.0 40.0
NO0725.01 Core 3867 2726 732 14 4 57.8 401.0
NO0725.02 Core 99999 21830 42 17 6 186.9 269.0
NO0725.03 Core 1292 2879 148 2 3 8.5 47.0
NO0725.04 Core 4043 36019 27 128 8 6.1 50.0
NO0725.05 Core 304 469 56 5 2 1.0 8.0
NO0725.06 Core 79880 34096 31 222 5 65.6 126.0
NO0725.07 Core 1220 1268 421 3 2 9.6 1116.0
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sn* Sb* Bi*
HERAMB-01 84 41 101.00 14 28 65
HE-01 13 72.00 5
HE-02 9 34.00 6
HE-03 85 80.00 28
NO0725.01 9.0 1.0 210 17.9 20 4.00 33 7
NO0725.02 7.0 3.0 258 174.4 6 1.00 2 2
NO0725.03 7.0 4.0 106 15.1 42 1.00 4 3
NO0725.04 15.0 10.0 278 231.1 4 3.00 20 27
NO0725.05 3.0 1.0 35 2.6 54 1.00 2 2
NO0725.06 7.0 9.0 390 232.7 4 2.00 24 69
NO0725.07 6.0 4.0 82 7.7 54 1.00 3 16
------------------
Sample No. Ga* S% V* Cr* Mn* Fe% Th* U* W*
HERAMB-01 10.00 29.30
HE-01 10.00 1317
HE-02 3.00 775
HE-03 24.00 2091
NO0725.01 6.15 1 3 113 8.48 1.00 5.00 5
NO0725.02 30.59 6 1 486 31.75 1.00 5.00 1
NO0725.03 2.86 6 6 196 4.25 2.00 5.00 3
NO0725.04 44.24 6 5 394 37.45 4.00 5.00 1
NO0725.05 .53 11 7 323 1.61 5.00 5.00 1
NO0725.06 34.60 7 8 505 35.13 3.00 7.00 5
NO0725.07 .91 5 5 255 2.06 11.00 5.00 1
------------------
Sample No. Sr* La* B*
HERAMB-01
HE-01
HE-02
HE-03
NO0725.01 3.0 6.00 2
NO0725.02 1.0 2.00 4
NO0725.03 2.0 7.00 3
NO0725.04 1.0 2.00 40
NO0725.05 3.0 9.00 2
NO0725.06 1.0 3.00 32
NO0725.07 4.0 17.00 2

The fact sheet was created on 04.05.2024
Questions or comments regarding the fact sheet can be emailed to:
ressursdatabaser@ngu.no
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