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THE ORE DATABASE
Deposit 1832 - 012 Bleikvassli
(Object Id: 2825)
(Last updated: 09.02.2017)

Location
County: Nordland Municipality: Hemnes (1832)
Map 1:50000: Røssvatnet (1926-1) Map 1:250000: Mosjøen
Coordinate system: EU89-UTM Zone 33
East: 448946 m. North: 7311810 m.
Longitude: 13.8784700 Latitude: 65.9232420
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Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Pb Kis Cu Ag
Importance
Raw material meaning: Regional Importance (reg. 28.05.2015)

Resources and production
Activity: Mining Reserves: 1000 thousand tons
Operating method: Open pit and underground mining Historical production: 5000 thousand tons


Products
Element/product Crude ore grade or quality Reg. date
Ag 25 g/t 10.12.1999
Cu 0.15 % 10.12.1999
Pb 2 % 10.12.1999
Zn 4.0 % 10.12.1999

Operations
From - To Activity Comments
1916 - 1916 Pitting Company/Institution :Hans Ro
1941 - 1943 Test mining Company/Institution :AS Bleikvassli gruber
1950 - 1973 Regular production Company/Institution :AS Bleikvassli gruber
1973 - 1993 Regular production Company/Institution :AS Sydvaranger
1993 - 1997 Regular production Company/Institution :AS Bleikvassli gruber
1997 - 1998 Core drilling Company/Institution :NGU
1998 - 1998 Core drilling Company/Institution :GeoDrilling

Mineralization
Era: Proterozoic Period: Neoproterozoic
Dating: 590 (-10\+10) million year Method: Rb/Sr
Genesis: Volcex Form: Layer
Main texture: Banded Min. distribution: Semi-massive (20-50 % ore minerals)
Main grain size: Medium grained (1-3 mm) Main alteration: Sericitisation
Strike/Dip: 210 / 50 Direction: 205
Plunge: 30
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 Phlogopite Major mineral (>10%)
Gangue mineral Muscovite Major mineral (>10%)
Gangue mineral Quartz Major mineral (>10%)
Gangue mineral Feldspar Subordinate mineral (1-10%)
Gangue mineral Chlorite Subordinate mineral (1-10%)
Gangue mineral Carbonate Subordinate mineral (1-10%)
Gangue mineral Epidote Accessory mineral (<1%)
Gangue mineral Staurolite Accessory mineral (<1%)
Gangue mineral Apatite Accessory mineral (<1%)
Gangue mineral Tourmaline Accessory mineral (<1%)
Ore mineral Galena Major mineral (>10%)
Ore mineral Sphalerite Major mineral (>10%)
Ore mineral Pyrrhotite Major mineral (>10%)
Ore mineral Pyrite Major mineral (>10%)
Ore mineral Chalcopyrite Subordinate mineral (1-10%)
Ore mineral Silver Accessory mineral (<1%)
Ore mineral Dufrenoysite Accessory mineral (<1%)
Ore mineral Hematite Accessory mineral (<1%)
Ore mineral Ilmenite Accessory mineral (<1%)
Ore mineral Rutile Accessory mineral (<1%)
Ore mineral Argentite Accessory mineral (<1%)
Ore mineral Valleriite Accessory mineral (<1%)
Ore mineral Sternbergite Accessory mineral (<1%)
Ore mineral Ottemannite Accessory mineral (<1%)
Ore mineral Gahnite Accessory mineral (<1%)
Ore mineral Jordanite Accessory mineral (<1%)
Ore mineral Freibergite Accessory mineral (<1%)
Ore mineral Seligmannite Accessory mineral (<1%)
Ore mineral Stromeyerite Accessory mineral (<1%)
Ore mineral McKinstryite Accessory mineral (<1%)
Ore mineral Gudmundite Accessory mineral (<1%)
Ore mineral Kesterite Accessory mineral (<1%)
Ore mineral Electrum Accessory mineral (<1%)
Ore mineral Antimony Accessory mineral (<1%)
Ore mineral Allargentum Accessory mineral (<1%)
Ore mineral Arsenic Accessory mineral (<1%)
Ore mineral Breithauptite Accessory mineral (<1%)
Ore mineral Cernyite Accessory mineral (<1%)
Ore mineral Dyscrasite Accessory mineral (<1%)
Ore mineral Herzenbergite Accessory mineral (<1%)
Ore mineral Jalpaite Accessory mineral (<1%)
Ore mineral Meneghinite Accessory mineral (<1%)
Ore mineral Gold Accessory mineral (<1%)
Ore mineral Bismuth Accessory mineral (<1%)
Ore mineral Stannite Accessory mineral (<1%)
Ore mineral Pyrargyrite Accessory mineral (<1%)
Ore mineral Jamesonite Accessory mineral (<1%)
Ore mineral Boulangerite Accessory mineral (<1%)
Ore mineral Bournonite Accessory mineral (<1%)
Ore mineral Tennantite Accessory mineral (<1%)
Ore mineral Chalcocite Accessory mineral (<1%)
Ore mineral Bornite Accessory mineral (<1%)
Ore mineral Marcasite Accessory mineral (<1%)
Ore mineral Tetrahedrite Accessory mineral (<1%)
Ore mineral Cassiterite Accessory mineral (<1%)
Ore mineral Molybdenite Accessory mineral (<1%)
Ore mineral Arsenopyrite Accessory mineral (<1%)
Ore mineral Magnetite Accessory mineral (<1%)

Lithology:
Relationship Rock Origin
Host rock Garnet-mica schist Sedimentary
Original rock :Greywacke
Metamorphic facies :Amphibolite
Host rock Microcline gneiss Intrusive
Original rock :Alkali syenite
481 (-2\+2) mill. years;..Method:U/Pb
Metamorphic facies :Amphibolite
Host rock Kyanite schist
Metamorphic facies :Amphibolite
Host rock Quartz-feldspar schist Extrusive
Original rock :Dacite
Metamorphic facies :Amphibolite
Host rock Graphite schist Sedimentary
Metamorphic facies :Amphibolite
Wall rock Quartzite
Metamorphic facies :Amphibolite
Wall rock Muscovite schist
Metamorphic facies :Amphibolite

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :230 / 40 Post-mineralisation ;...Effect :Controls
Host rock Fold axis Dir./Plunge :205 / 25 Post-mineralisation ;...Effect :Controls

Information(s) in free text format
Free text
The sediment-hosted Bleikvassli deposit produced c. 5.0 Mt of ore grading about 0.15 % Cu, 4.0 % Zn, 2 % Pb, and 25 g/t Ag in the period 1957-1997. Structurally below the deposit is a thick and laterally persistent unit of amphibolite, a large gabbroic sill or a massive volcanic flow. Some of the quartz-feldspar gneisses represent felsic volcanics, including the units associated with the deposit. The ore body consists of a discontinuous layer of massive, semi-massive and disseminated sulphides, is more than 1500 m long, up to 300 m wide and up to 20 m thick in fold hinges. In-situ values based on more than 1400 drill-hole analyses are 0.27 % Cu, 5.17 % Zn, 2.72 % Pb, 45 g/t Ag and 0.21 g/t Au. The average iron content is 16.9 %, showing that it is a semi-massive ore body. Three types of sulphide ore are recognized in the Bleikvassli deposit: 1) massive pyrite ore, 2) massive pyrrhotite ore and 3) mobilisate-type veins and veinlets, mainly in the wallrocks. The mobilisates are enriched in galena, chalcopyrite, sulphosalts, silver and gold. It has been suggested that the observed unconformity between the Kongsfjell and Anders Larsa Groups represented a pathway for both the volcanics and the hydrothermal solutions forming the Bleikvassli deposit.

Bibliography:
From NGU's Reference Archive:
Aart; Kruse , 1977
Diamantborhullene 1-4/75 på anomali 1, A/S Bleikvassli Gruber.
;Norges geologiske undersøkelse;TEKNISK RAPPORT;Bergarkivet; No.BA 6575;1 pages
Abstract:
Anomali 1, som ligger N-for hovedforekomsten ble funnet i 1973. Diamantboring i 1974 påviste malm med drivverdige mektigheter og gehalter. Dermed startet en systematisk oppboring av denne malmen. Diamantboringene fortsatte i 1975 og 1976 og skal også videreføres i 1977. I 1975 ble det boret 3 hull mot de dypere deler av anomali 1 med skjæringer med (den antatte) malmsonen på ca. nivå 180 m.o.h., og 1 hull fra land ytterst i nord med malmskjæring på ca. nivå 300 m.o.h. Unntatt hull 2/75 ble det påtruffet malmmineralisering, men bare i hull 4/75 ytterst i nord drivverdige gehalter og mektighet, (kfr.pro- filene). KONKLUSJON. Anomali 1 - malmens nordgrense er ennå ikke fastlagt. Malmen fortsetter nord for profil oB i Kjøkkenbukta. -Anomali 1 malmen er ikke påvist som drivverdig malm under nivå 280 m.o.h. Selv om det er boret for lite til å kunne fastlegge den drivverdige malmens nedre grense, må den i profil 4 og 6 ligge mellom 200 og 290 m.o.h. Borhull 1/75 i profil 6 med en malm- skering på 0,65 m med 3,5 % Zn på nivå 170 er ikke i strid med en slik mulighet.

Bjerkgård, Terje , 1998
Metal and mineral distribution in the Bleikvassli Zn-Pb deposit, Nordland, Norway
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.98.064;52 pages
Abstract:
Studies of metal zonations in the Bleikvassli deposit are important, both for detailed planning of a drilling program and for subsequent interpretations of the results. For this investigation, drillhole data were selected from profiles throughout the deposits at intervals of about 100 meters, except for the old, southern part of the deposit, where all profiles where used because of scarcity of data. The total number of drillcore intersections analysed is 461 and is composed of 1437 individual analyses, representing 1953 meters of drillcore. The data has been weighted according to the lengths of the analyzed intervals and average of each ore intersection have been calculated. This study show the presence of a pronounced metal zonation in the deposit, with enrichment of copper in the deeper, central part of the deposit, whereas zinc and lead are relatively enriched towards the upper and more northern part of the deposit. This zonation accords with a mineralogical zonation: pyrrhotite ore contains chlorite and/or biotite is relatively enriched in copper; pyrite ore contains muscovite and/or biotite, and is relatively enriched in zinc and lead. A strong correlation between zinc and lead shows that no major redistribution and separation of these metals took place during the tectonic events affecting the deposit, and that the large-scale zonation observed are likely to be of primary origin. Silver and lead are highly correlated, support- ing the view of galena as the main silver carrier in the deposit. Manganese, and to some extent barium, are associated with the copperrich part of the deposit. This could be a coincidence, due to a primary enrichment in the sediments. Referring to idealized models for SEDEX type deposits, the pyrrhotite-ore enriched in copper could represent the proximal part of the deposit and the pyrite-ore enriched in zinc would be the more distal part. A

Bjerkgård, Terje; Larsen, Rune B.; Marker, Mogens , 1997
Regional setting of the Bleikvassli Zn-Pb deposit in Nordland,Norway
;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU Bulletin; No.433;34-35 pages

Cook, Nigel , 1993
Conditions of metamorphism estimated from alteration lithologies and ore at the Bleikvassli Zn-Pb-(Cu) deposit, Nordland, Norway.
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.73 (4);226-233 pages
Abstract:
Electron probe microanalysis of silicate and sulphide phases within ores, of microcline gneiss, garnet-biotite schist and other characteristic alteration assemblages associated with the Belikvassli Zn-Pb-(Cu) massive sulphide orebody were carried out. Using established geothermobarometric methods, peak metamorphic conditions for the portion of the Rødingsfjell Nappe Complex hosting the orebody are estimated. Most methods employed indicate peak conditions in the range 540-570°C and 7.5-8.5 kbar. Only a single metamorphic episode is recorded in the rocks studied here. Geothermometric calibrations based on compositions of garnet-chlorite pairs give temperature conditions of approx. 510-520°C, suggesting temperatures on the retrograde cooling path. Estimates of peak and retrograde metamorphism are consistent with observed mineralogical and textural evidence recorded in the rocks.

Dalsegg, Einar , 1999
CP-borhullsmålinger ved Bleikvassli Gruber i 1998, Hemnes, Nordland.
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.99.004;21 pages
Abstract:
For vurdering av mulig gjenåpning av gruva ble det sommeren 1998 utført et omfattende borprogram i Bleikvassli for påvisning av eventuell ny malm langs hovedmalmens vestflanke. NGU fikk i oppgave å teste om en ved bruk av CP-målinger kunne følge mineraliserte nivåer og strukturer fra borhull til borhull, og dermed ha en bedre styring på boringene. I motsetning til tidligere CP-målinger i gruveområdet har årets målinger vist at bruk av CP-målinger gir nyttig tilleggsinformasjon. Selv om boringene ikke påviste nye malmfunn, gav CP-målingene informasjon om utbredelsen av malm- og grafittnivåene i denne delen av gruveområdet. Dette hadde stor betydning, spesielt i forbindelse med hvor langt de negative hullene skulle bores.

Dalsegg, Einar , 1999
TFEM-målinger Buktliklubben, Bleikvassli, Hemnes, Nordland
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.99.003;42 pages
Abstract:
Som en del av Norlandsprogrammet undersøkelser tilknyttet gjenåpning av Bleikvassliforekomsten, ble det i 1998 utført TFEM-målinger i et område ved Buktliklubben øst for Bleikvassli Gruber. Hensikten vår å se om geofysiske bakkemålinger kunne føre til påvisning av økonomiske interessante mineraliseringer i dette området som ikke var undersøkt med denne type målinger tidligere. Målingene har innenfor det undersøkte området påvist flere anomalier hvor de aller fleste ser ut til å skyldes grunne ledere. Måledata indikerer at anomaliårsken til de mest markerte sonene skyldes grafitt, og undersøkelsen har ikke ført til indikasjoner som umiddelbart synes å skyldes massive sulfidmineraliseringer av betydning.

Elvebakk, Harald; Dalsegg, Einar , 1996
Geofysiske målinger på Kjøkkenbukta, Bleikvassli Gruber, Hemnes, Nordland
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.96.076;64 pages
Abstract:
Det er gjort TFEM-målinger på Kjøkkenbukta like nord for Bleikvassli Gruber. Hensikten var å kartlegge en eventuell fortsettelse av Kjøkkenbuktmalmene (linse A og B) østover og utover bukta. Det ble benyttet et måleopplegg hvor energiseringskabelen var fjernet fra måleområdet for om mulig å redusere effekten av kjente, grunne grafittsoner. Resultatene viste at måleopplegget fungerte godt, og grunne, kjente grafitt- soner påvirket ikke målingene. Målingene indikerte en dyp leder med en utstrekning på minst 600 m med et tolket dyp på 100 - 150 m. Lederen har varierende ledningsevne, og bare en del av sonen har ledningsevne tilsvarende malmsonene det ble jordet i. Dette kan tyde på at malmsonen (linse A og B) ikke går vesentlig lenger østover, noe oppfølgende boringer har bekreftet. Målingene indikerte også forbindelsen vestover til Nordmalmen og en mulig fortsettelse av linse A vestover. Det anbefales boring på disse sonene og på dyplederen ute på Kjøkkenbukta.

Elvebakk, Harald; Rønning Jan S. , 1998
Sprekkekartlegging med georadar ved Bleikvassli Gruber
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.98.038;12 pages
Abstract:
I forbindelse med store setninger i fjellet ved gruveåpningen ved Bleikvassli Gruber er det gjort georadarmålinger for å kartlegge sprekker og sprekkesoner som kan tenkes å ha betydning for arbeidet med å tette fjellet og dermed hindre vanninntrengning i gruva.

Grønlie, Gisle , 1975
Gravimetriske målinger ved Bleikvassli Gruver, 30/6-2/7 1975.
;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 6577;3 pages
Abstract:
Gravimetriske målinger er utført over 6 VLF-anomalier, hvorav 3 er i relativt nærhet av gruva og 3 er på nordsiden av Kjøkkenbukta. Hensikten med målingene var å prøve å skille ut grafitt-fylitt skifersoner som gir kraftige elektriske og elektromagnetiske anomalier fra andre ledende soner. Forsøk i Bleikvassli i fjor med gravimetriske målinger over den nye malmen og grafittskifre viste at over malmen er det en positiv tyngdeanomali mens grafittskiferen ikke gir noen anomali. Profilene er fra 120 til 240 m lange. Måleavstand er 20 m i utkanten av og 10 m over selve anomalien. Samtidig med de gravimetriske målingene foretok gruvemåler Henriksen høydebestemmelse av målepunktene. Ut fra de gravimetriske målingene peker 4 områder seg ut som interessante.

Horvath
Bleikvassli Grube Malmkart. Dagåpninger og diamantboringer 1 : 200?
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 9

Juve, Gunnar , 1961
Bleikvassli grube. Profilskisse av dagbrudd
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 1790

Moralev, Gleb V.; Bjerkgård, Terje; Larsen, Rune B. , 1997
Geology of the Kjøkkenbukta orebody, Bleikvassli Gruber, Nordland, Norway
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.96.155;33 pages
Abstract:
The aim of the present study was to obtain more data regarding geological relations between the massive sulfide ore and wall rock, especially the microcline gneiss, the genesis of which is a subject of discussion. Another objective was to get more data about the distribution of gold in the ore and wall rocks. The choice of mapping target was influenced both by geological relationships and interests of the mining company. Mapping of the mining level 290 meters above sea level (m.a.s.l.) was completed during two weeks in April and May, 1996. Both walls and roof along 190 m of the underground workings were mapped in the scale 1:100. The working face of the drifts and some interesting localities on the walls were mapped in approximately the scale 1:50. The contact between the NNW part of the ore zone in the Kjøkkenbukta ore- body and the microcline gneiss body is discordant and the microcline gneiss is wrapped around the ore zone. The relationship between the microcline gneiss and the surrounding mica schist is complicated by superimposed tectonic events. A single observation of an angular unconformity between the schist and micro- cline gneiss can be interpreted in two ways; either as a primary intrusive, or a tectonic contact. Massive ore and wall rocks in the NNW ore zone have discor- dant relationships to each other, and the ore cuts through schistosity and the hinge zones of small F, folds. This is probably a result of tectonic emplacement of the ore along a shear zone. Microscopic recognizable native gold or electrum have not been found in the massive ore of the Kjøkkenbukta orebody. This is an agreement with previously obtained data for the Bleikvassli deposit in general (Moralev et al., 1995) Native gold and electrum have been found in veinlets of remobilized ore and deposition of gold and electrum can be correla- ted temporally with carbonate-chlorite veinlets.

Moralev, Gleb V.; Larsen, Rune B.; Bjerkgård, Terje , 1995
Distribution of precious metals in the Bleikvassli Zn-Pb Sedex type deposit, Nordland, Norway
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.95.154;120 pages
Abstract:
In contrast to the volcanic hosted massive sulfide deposits, the presence of recoverable gold is not a common feature of sedex type Pb-Zn deposits. However, the available data suggest that the gold content in the Bleikvassli deposit could be higher than previously assumed. This report comprise the results of field work on the Bleikvassli Pb-Zn deposit, Nordland, Norway. The main goals have been to study the distribution of precious metals in the massive ore in the wall rocks and furthermore to evaluate the mode of occurrence of precious metals. During the field season in 1995, 11 drillholes from profiles 360N, 520N and 700-740N were relogged and sampled in continuous intervals across the ore zone. Five short profiles were also sampled across the massive sulfide body in underground workings. Drill hole intersections, which showed gold and/or silver enrichment during routine analysis by the mining company, were sampled for microscopic and microprobe studies. During the study of gold and silver rich intervals from the drill holes, it was clear that mobilizate type veinlets and disseminated sulfide mineralizations hosted by quartz +- feldpar veins, "quartzite-like" rocks and muscovite schist dominate in the precious metal rich intervals. Until now, 434 samples have been analyzed.

Olesen, Odleiv; Rueslåtten, Håkon , 1997
Vurdering av årsak til setninger i Bleikvassli Gruber - delrappport om tilslamming av Kotabekken
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.97.191;36 pages
Abstract:
Bleikvassli Gruber ble den 25.september 1997 utsatt for setninger og vanninn- trenging. Dette resulterte i at gruva ble fylt med vann i løpet av en uke og at en 10 meter høy vannkraftsdam tilhørende Statkraft ble ødelagt. NTNU, NORSAR og NGU har fått i oppgave av Gjensidige Forsikring å vurdere årsakene til setningen i gruva, og spesielt muligheten for at et jordskjelv som er registrert i området kan ha utløst setningen. Denne rapporten utgjør NGU's bidrag til vurderingene. Det vil bli utarbeidet en felles konklusjon fra de tre institusjonene.

Ramberg, H. , 1942
Rapport fra Bleikvassli Zn - Pb forekomst.
;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 1017;1 pages
Abstract:
Kort beskrivelse av Bleikvassli-malmens utgående og omgivende bergarter. Øverst til venste står navn og adresse til Hans Ramberg. Hvorvidt han er forfatter eller mottager av rapporten vites ikke.

Stuedahl, H. , 1942
Bleikvassli gruber. Malmkart 1:500
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 17

Stuedahl, H. , 1942
Bleikvassli gruber. Topografisk kart 1:2 000. Plankart med stoller og diamantboring
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 19

Vokes, F.M. , 1962
Contributions to the mineralogy of Norway. No. 15. Gahnite in the Bleikvassli ore.
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.42 (4);317-329 pages
Abstract:
Frie emneord: Gahnitt

Vokes, Frank M. , 1960
Contributions to the mineralogy of Norway. No. 7. Cassierite in the Bleikvassli ore.
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.40 (3-4);193-201 pages
Abstract:
Bleikvassli Gruber A/S in Nordland fylke, some 50 kilometres south of Mo i Rana, (Fig.1) is at the present mining about 100,000 tons per year of pyritic lead-zinc ore. Economic products are lead, zinc and pyrite concentrates. During the course of a systematic mineralogical examination of samples of the ore, the writer detected the presence of small, rounded to euhedral grains of a brown mineral in the heaviest, non-magnetic frcations. Optical and x-ray powder determinations proved this mineral to be cassiterite (SnO2)1. Following this, cassiterite was observed and studied in thin sections of the Bleikvassli ore. Colorimetric determinations of the SnO2 content of the ore were also made on more than 30 samples. At the same time, a large sample of the mine tailings was examined mineralogically and chemically. Cassiterite, being non-flotable or nearly so, would not be recovered in any of the concentrates being produced at the mine and would therefore report in the tailings. These are at the present time being allowed to fill up a small lake and thus would be available for re-treatment if the amount of tin in them should prove to be economically recoverable. Frie emneord: Kassiteritt

Ramberg, Ivar B. , 1967
Kongsfjell-områdets geologi, en petrografisk og strukturell undersøkelse i Helgeland, Nord-Norge.
;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.240;1-152 + k pages
Abstract:
The area investigated is situated in the Rødingsfjell nappe of the Norwegian Caledonides in Helgeland, North Norway. The study is divided into two main parts; the first structural and the second petrographic. The first section contains a description of different structural elements and the various mesoscopical and macroscopical structures encountered in each of the structural subareas. It is concluded that at least some parts of the area investigated have suffered three phases of folding. The first (F1) phase produced large-scale and small-scale similar-type folds following both WNW and SSW trending axes. Contemporaneously the western part of the area, the marble-rich Anders Larsa Group was thrust at a low angle to the east over the Kongsfjell Group constituting the complex, transversal Jørentind Synform. During the second phase of folding (F2) the Kongsfjell Group was "wrapped" around the Anders Larsa Group, the latter forming the core of a regional and almost isoclinal fold plunging to the SSW. The effects of the second phase are less evident towards the east. The small-scale second phase folds are more open, assymetric, flexural-slip folds. Both the Anders Larsa and the Kongsfjell Group are overthrust by a nappe in SSW (Tustervann region). During the third deformation the F1 and F2 structures were deformed in the western part of the area.

References not to be found in NGU's Reference Archive.:
Bjerkgård, T. 1999: Metal distribution and formation of the Bleikvassli Zn-Pb-(Cu) deposit, Nordland, Norway. in Stanley ,C. et. al. Mineral Deposits: processes to processing. Conference Proceedings SGA-IAGOD, London 1999, p.931-934.


Cook, N.J., Spry, P.G. & Vokes, F.M. 1999: Mineralogy and textural relationships among sulphosalts and related minerals in the Bleikvassli Zn-Pb-(Cu) deposit, Nordland, Norway. Mineralium Deposita, v.34, p.35-56.


Rosenberg, J.L., Spry, P.G., Jacobson, C.E., Cook, N.J. & Vokes, F.M. 1999: Thermobarometry of the Bleikvassli Zn-Pb-(Cu) deposit, Nordland, Norway. Mineralium Deposita, v.34, p.35-56.


Skauli, H., 1992: On the formation of Zn-Pb deposits; a case study of the Bleikvassli deposit, Northern Norway. Doctoral thesis, Univ. Oslo, 1992

Fieldsamples
Sample No. Sample type Miscellanrous
DH10-96 Core
Stored: Bleikvassli
Comment: Semimassive pyrite-sphalerite-galena ore with subordinate chalcopyrite. 3.4 m (151.1-154.5 m).
No. of registrated element analyses = 1
DH24-91 Core
Stored: Bleikvassli
Comment: Massive pyrite-sphalerite ore, rich in galena. Subordinate chalcopyrite. 5.8 m (33.8-39.6 m).
No. of registrated element analyses = 1
DH24-96 Core
Stored: Bleikvassli
Comment: Massive pyrite-sphalerite ore with galena. Subordinate chalcopyrite. 2.6 m (9.5-12.1 m)
No. of registrated element analyses = 1
DH2-90A Core
Stored: Bleikvassli
Comment: Semimassive pyrrhotite-sphalerite mineralization. Subordinate galena and chalcopyrite. 0.95 m (393.5-394.45).
No. of registrated element analyses = 1
DH2-90B Core
Stored: Bleikvassli
Comment: Semimassive pyrrhotite mineralization. Subordinate sphalerite, galena and chalcopyrite. 1.2 m (388.8-390 m).
No. of registrated element analyses = 1
DH2-90C Core
Stored: Bleikvassli
Comment: Semimassive pyrite-sphalerite-galena ore. Subordinate chalcopyrite. 1.1 m (391-391.1 m).
No. of registrated element analyses = 1
DH29-96 Core
Stored: Bleikvassli
Comment: Massive pyrite with subordinate sphalerite, galena and chalcopyrite. 1.2 m (20.1-21.3).
No. of registrated element analyses = 1
DH3-93 Core
Stored: Bleikvassli
Comment: Pyrite-pyrrhotite impregnation in muscovite schist. Galena rich, subordinate sphalerite and chalcopyrite. 1.2 m (30.2-31.4 m).
No. of registrated element analyses = 1
DH5-90 Core
Stored: Bleikvassli
Comment: Semimassive pyrite-sphalerite ore. Subordinate galena and chalcopyrite. 2.0 m (457.4-459.4 m).
No. of registrated element analyses = 1
DH6-94 Core
Stored: Bleikvassli
Comment: Impregnation of pyrrhotite, with lesser sphalerite, galena, and chalcopyrite in muscovite-biotite schist. 1.3 m (1.4-2.7 m).
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:


Analyse Results
from
Deposit Area 1832 - 012 Bleikvassli

Element analyses

( *=parts pr. million, #=parts pr.billion, Negative values means below detection limit value.)
Sample No. Sample Type Cu* Zn* Pb* Co* Ag* Au# As*
DH10-96 Core 3114 56525 33260 26 14.6 100.0 311
DH24-91 Core 1318 88814 34108 39 77.7 134.0 50
DH24-96 Core 5510 49686 25930 96 33.1 110.0 740
DH2-90A Core 3183 33501 4644 1 7.7 50.0 3
DH2-90B Core 6392 15301 7561 1 11.8 144.0 7
DH2-90C Core 1865 58930 28954 33 31.0 59.0 26
DH29-96 Core 5065 25617 23336 112 90.0 425.0 185
DH3-93 Core 603 19215 41354 3 304.7 178.0 298
DH5-90 Core 904 52100 10214 25 7.2 41.0 37
DH6-94 Core 2334 18117 18471 3 60.3 178.0 45
------------------
Sample No. Cd* Ba* Sb* Bi* Mn* Fe%
DH10-96 181.1 17 82 21 704 18.53
DH24-91 284.0 11 101 101 200 32.16
DH24-96 206.8 38 77 50 669 22.03
DH2-90A 136.4 79 47 9 676 12.37
DH2-90B 49.1 181 144 25 437 10.65
DH2-90C 199.7 104 186 27 620 16.76
DH29-96 138.4 27 81 157 734 27.90
DH3-93 81.2 5 740 119 403 3.12
DH5-90 157.4 95 51 11 532 17.42
DH6-94 48.9 19 186 39 356 6.92


The fact sheet was created on 18.10.2021

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