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MALMDATABASEN
Forekomstområde 1832 - 020
(Sist oppdatert 08.des.2025)

Navn på deposit area : Grasvatnet
(Objekt Id : 1832,020,00,00)

Lokalisering
Fylke : Nordland (18) Kommune : Hemnes (1832)
Kart 1:50000: Store Akersvandet (2027-3) Kart 1:250000: Mo i Rana
Markeringspunkt: Lengdegrad: 14.3943340 Breddegrad: 66.0545600
EU89-UTM Zone 33 (Coordinates IS confirmed)
X-koord: 472569 m. Y-koord: 7326123 m.

Materialtype
Hovedtype: Basemetaller (Cu,Zn,Pb,Fe sulfider,As,Sb,Bi,Sn) Subtype: Kobber
Element(s): Cu Zn
Production
Activity: Prospektering Reserves:
Prod. method: Production:
Prod. status: Volume of dump:

Betydning
Offentlig: (No data)
Economical: Ikke vurdert

Operations
From - To Activity Comments
1993 - 1994 Geochemistry Company/Institution :NGU
1996 - 1996 Sampling Company/Institution :NGU
1996 - 1996 Detail mapping Company/Institution :NGU

Mineralization
Era: Proterozoic Period: Neoproterozoic
Dating: Method:
Genesis: Ukjent Form: Uregelmessig
Main texture: Min. distribution: Disseminert
Main grain size: Grovkornet (>3 mm) Main alteration:
Strike/Dip: Direction:
Plunge:
Stratigraphic classification of host rock
Era: Proterozoic Period: Neoproterozoic
Province: Caledonides
Geotec.unit: Rødingsfjell Nappe Complex
Tectonic complex:
Igneous complex:
Group: Kongsfjell Formation:

Mineralogy
Relationship Mineral Amount
Gangue mineral Biotite Major mineral (>10%)
Gangue mineral Garnet Major mineral (>10%)
Gangue mineral Amphibole Major mineral (>10%)
Gangue mineral Quartz Major mineral (>10%)
Ore mineral Chalcopyrite Major mineral (>10%)
Ore mineral Pyrrhotite Major mineral (>10%)
Ore mineral Sphalerite Subordinate mineral (1-10%)
Ore mineral Galena Accessory mineral (<1%)
Ore mineral Molybdenite Accessory mineral (<1%)

Lithology:
Relationship Rock Origin
Host rock Granatglimmerskifer Sedimentary
Original rock :Argillaceous sediment
Metamorphic facies :Amphibolite

Opplysning(er) i fritekstformat
Fri tekst
Basert på regionale jordprøvetaking i 1993 og 1994 ble det funnet sulfidmineralsering i fast fjell like sør for bredden av Grasvatnet nord for utløpet av Oksfjellelva. Mineraliseringene består av svak impregnasjon av kobberkis, sinkblende og blyglans i granat-kvarts-amfibol-biotittbergart. Bergarten er lokalt skifrig, men vanligst er den massiv med uorienterte nåler av fargeløs amfibol med interstitielle sulfider og andre silikater. Ofte er den rusten og har et gossan-preg. Det er også et tynt lag med kyanitt-granat-turmalin assosiert. Mineralisert gossan opptrer i tynne linser (2-10 m) med en begrenset utstrekning, typisk 10-50 m. Sannsynligvis har det vært et kontinuerlig lag som er avrevet som følge av deformasjon. Sonen er totalt 5-600 m lang og kiler ut mot sør mot Oksfjellelva. Kobberkis dominerer og er typisk assosiert med magnetkis, ofte i lamellær epitaksial vekst. Sinkblende opptrer underordnet, mens blyglans opptrer kun lokalt. Forholdsvis grovkornet molybdenglans opptrer spredt.

Bibliography:
From NGU's Reference Archive:
Krog, Reidar , 1996
Soil geochemistry of the Bleikvassli area (Status Report No.1) Regional investigations of the area between Røssvatnet and Målvatnet
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.95.155;85 pages
Abstract:
A combined geological, geophysical and geochemical exploration aimed at finding new ore reserves in the vicinity of the Bleikvassli mine, Nordland county was initiated by NGU in 1993. This report describes a regional soil (c-horizon/ weathered material) geochemical survey carried out as a part of this project. An area of 800 sq.km was sampled at a density of 1 sample per square kilometer. The samples were analysed for the HNO3-extractable amouths of Ba,Be,Ca,Ce,Cd,Co,Cr,Cu,Fe,K,La,Li,Mg,Mn,Mo,Ni,P,Pb,S,Sc,Sr,Ti,V,Zn,Zr,Y, the total amounts of C (Leco), S(Leco), Au (fire assay) and the grain size (sieving). The single-element symbol maps showed several anomalous areas and detailed sampling of the three most interesting areas was carried out in 1994-1995. These investigations are described in NGU Report 95.156, but the results are also considered in this report and evaluated together with the other anomalous areas within the Bleikvassli area. The need for further investigations is discussed.

Krog, Reidar , 1996
Soil geochemistry of the Bleikvassli area (Status Report No.2) Detailed investigations of the Hallvarddalen, Artfjellet and Kjennsvatnet areas
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.95.156;104 pages

Krog, Reidar , 1997
Soil geochemistry of the Bleikvassli area ( Status Report No.3). Detailed investigation of the Grasvatnet area.
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.97.106;44 pages
Abstract:
A combined geological, geophysical and geochemical exploration project aimed at finding new ore reserves in the vicinity of the Bleikvassli mine, Nordland county was initiated by NGU in 1993. A number of the anomalous areas detected during this regional survey were followed up with more detailed investigations. One of these was the Grasvatnet area where detailed geological mapping revealed sulphide-impregnations with restricted thickness and extent. Deep geophysical anomalies (Transient Field EM) are connected with these minerali- sations and this report deals with the results of detailed soil sampling around the mineralisations and geophysical anomalies.

Bjerkgård, Terje; Larsen, Rune B. , 1996
Follow-up studies in the Okstindan Area, The Rødingsfjall Nappe Complex, Nordland, Norway
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.96.157;34 pages
Abstract:
Follow-up work has been conducted in three restricted areas of the 1200 km2 large Okstindan Area on the basis of earlier anomalies found during regional surveys. The three areas have been subjected to detailed geophysical mapping, mineralogical studies and sampling for whole-rock geochemistry. Mineralizations in the area consist of non-economic sulfide-impregnations with restricted thickness and extent. Skarn-type mineralizations consisting of mainly clinoamphibole, garnet, quartz and biotite, found in the Brunesbekken and Grasvatnet areas, have not previously been reported from the Okstindan Area. Similar types of mineralizations are, however, typical for the Plurdalen Group in the Mofjellet Area. The mineralization in Rabotsbekken is hosted by quartzite and quartzitic schists and can be classified as a low-grade sulfide mineralization or a high-grade exhalite. Deep geophysical anomalies (Transient Field EM) are connected to the mineralizations in both Brunesbekken and Rabotsbekken. However, graphitic schists are associated with the mineralizations and the cause of the anomalies may be graphite or massive sulfides.

Bjerkgård, Terje , 1998
The Bleikvassli Project, field report 1997
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.98.074;28 pages
Abstract:
This report presents preliminary results of detailed geological follow-up studies and diamond drilling carried out in the Okstindan Area, Nordland, Norway in the period July to August 1997. Preliminary results from drilling done in November and December 1997 is included in this report. Field work to the south and at the base of the Okstindan massif along the Kongsfjell / Anders Larsa contact revealed no signs of mineralization. Extensive mineralized zones at Gjetarfjellet to the east of Røssvatnet have been mapped out. Because of weathering, the nature of the mineralizations is not known and further work to expose fresh surfaces is highly recommended. A Cu-Ni mineralization related to ultramafic rocks was found at the border to Sweden. The extent of this mineralization is too small to be economic, judged from the surface exposure. However, geophysics indicate a larger extent at depth and also other anomalies in the area. More field work and ground geophysics is recommended in the area.

Fieldsamples
Sample No. Sample type Miscellanrous
TB96-016 Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
TB96-017A Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
TB96-017B Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
TB96-018 Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
TB96-019 Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
TB96-020 Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
TB96-021 Bedrock
Sampler :T. Bjerkgård
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:


Analyse Results
from
Forekomstområde 1832 - 020 Grasvatnet

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#
TB96-016 Bedrock 5201 194 24 16 19 3.4 50.0
TB96-017A Bedrock 38231 2743 581 12 12 12.0 140.0
TB96-017B Bedrock 12865 1717 1558 6 10 9.5 256.0
TB96-018 Bedrock 54898 348 17 8 15 24.9 127.0
TB96-019 Bedrock 12966 1345 73 12 13 6.6 188.0
TB96-020 Bedrock 15820 5867 5520 6 10 86.0 641.0
TB96-021 Bedrock 13808 29233 6103 28 18 15.3 207.0
------------------
Sample No. As* Cd* Ba* Mo* Sb* Bi*
TB96-016 -10 .5 114 -2.00 -5 29
TB96-017A -10 8.3 36 163.00 -5 44
TB96-017B 25 3.5 89 197.00 -5 36
TB96-018 -10 5.8 41 -2.00 9 46
TB96-019 -10 4.0 9 17.00 -5 8
TB96-020 125 13.0 46 239.00 -5 71
TB96-021 96 40.5 148 105.00 -5 44


Faktaarket ble generert 13.06.2026

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