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THE ORE DATABASE
Prospect 1833 - 011 Hammartjørna
(Object Id: 2170)
(Last updated: 04.09.2018)
Belongs to the Province: Mofjellet sink-bly
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Mo i Rana (1927-1) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 463720 m. North: 7351535 m.
Longitude: 14.1917060 Latitude: 66.2816280
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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 Cu Kis
Importance
Raw material meaning: Not Assessed (reg. 09.02.2017)

Resources and production
Activity: Pitting Reserves:
Operating method: Historical production: ,015 thousand tons


Products
Element/product Crude ore grade or quality Reg. date
Ag 7 ppm 13.03.1992
Cu .2 % 13.03.1992
Kis 10 % 13.03.1992
Pb .4 % 13.03.1992
Zn 1.4 % 13.03.1992

Operations
From - To Activity Comments
1976 - 1977 Geology
1984 - 1984 Core drilling
2007 - 2007 Geophysics Company/Institution :GEXCO Norge AS
TEM survey (by Skytem)
2008 - 2008 Core drilling Company/Institution :GEXCO Norge AS
One hole between Hammatjønna and Hesjelia, which confirmed a connection between the two mineralizations.
2008 - 2009 Geology Company/Institution :NGU

Mineralization
Era: Proterozoic Period: Neoproterozoic
Genesis: Volcex Form: Ruler
Main texture: Banded Min. distribution: Disseminated (<20 % ore minerals)
Main grain size: Medium grained (1-3 mm) Main alteration:
Strike/Dip: 120 / 15 Direction:
Plunge:
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 Quartz Major mineral (>10%)
Gangue mineral Hyalophane Major mineral (>10%)
Gangue mineral Muscovite Major mineral (>10%)
Gangue mineral Epidote Accessory mineral (<1%)
Gangue mineral Kyanite Accessory mineral (<1%)
Gangue mineral Biotite Accessory mineral (<1%)
Gangue mineral Plagioclase Accessory mineral (<1%)
Ore mineral Sphalerite Major mineral (>10%)
Ore mineral Pyrite Major mineral (>10%)
Ore mineral Galena Subordinate mineral (1-10%)
Ore mineral Pyrrhotite Subordinate mineral (1-10%)
Ore mineral Chalcopyrite Subordinate mineral (1-10%)
Ore mineral Freibergite Accessory mineral (<1%)
Ore mineral Molybdenite Accessory mineral (<1%)

Lithology:
Relationship Rock Origin
Host rock Muskovittgneis Extrusive
Original rock :Tuff
Metamorphic facies :Amphibolite

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :120 / 15 Post-mineralisation ;...Effect :None

Information(s) in free text format
Free text
The Hesjelia zone is situated above a probable discordance on the top of Mofjellet. In this area two mineralizations (Hesjelia and Hammertjønna) are outcropping in a major fold closure of a recumbent fold structure oriented east-west. The structure has its closure to the south and has a length of c. 2.9 km. The mineralizations are associated with a tightly folded unit of muscovite gneiss. The mineralization at Hammertjønna is outcropping discontinuously over a length of nearly 350 m in five small showings. Drillholes from the 1980s yielded intersections of 0.6 to 3.85 m averaging 1.4 % Zn, 0.4 % Pb, 0.2 % Cu, 7 g /t Ag, with the best intersection having 3.05 m with 3.3 % Zn, 1.1 % Pb, 0.3 % Cu and 9 g /t Ag. Portable XRF identified a halo of barium (0.1-0.3 % Ba) up to 0.5 m in the main mineralized zone. Geophysical data (TEM) indicated a connection between the mineralizations at Hammertjønna and Hesjelia and drillhole 4808 in 2008 strengthened this assumption. At about 110 m depth a weak mineralization was intersected in the hole assaying 0.14 % Cu, 0.09 % Pb, 0.60 % Zn and 3 g/t Ag over 6 m interval. Anomalous barium-values (up to 0.3 %) were found beneath the richest mineralization in the hole. Main sulfides in both Hesjelia and Hammertjønna are pyrrhotite or/and pyrite and sphalerite, while chalcopyrite is subordinate to accessory and galena is accessory mineral. The content of galena is generally slightly higher in the Hammertjønna deposits. Among trace minerals are silver-bearing phases, mainly freibergite, most common, but also some bismuth telluride are found. These phases are generally present as inclusions in galena. The mineralizations in the Hesjelia zone are characterized by high barium content, mainly present in hyalophane with 21-28% celsian component (analyses by SEM). In addition some barite was found in the Hesjelia showings, and barium-bearing mica with 2.5-5.5 wt. % Ba is present in both Hesjelia and Hammertjønna. The main gangue minerals in the Hesjelia zone are quartz, muscovite, biotite, plagioclase and hyalophane. Kyanite is quite common in the Hammertjønna deposits, while clinoamphibole (probably hornblende) is present in the Hesjelia deposits.

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.

Håbrekke, Henrik , 1977
Magnetiske og elektromagnetiske målinger fra helikopter syd og øst for Mo i Rana.
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.1490;9 pages

References not to be found in NGU's Reference Archive.:
Kruse, A. 1984: Hesjeli. Interimrapp. nr.8405. Prospektering A/S.


Kruse, A. 1985: Malmleting: Foreliggende resultater av fjorårets kjerneboringer. Intern rapport. Bergverksselskapet Nord-Norge A/S.

Fieldsamples
Sample No. Sample type Miscellanrous
HAMMERTJ-01 Bedrock
Sampler: T. Bjerkgård/...Stored: Løkken
Comment: Lenses of sl and ga in quartz-sericite schist
No. of registrated element analyses = 1
HAM-01 Bedrock
Sampler: T. Bjerkgård/...Stored: Løkken
Comment: Quartz-sericite schist with py impregnation, minor sl, accessory ga and cpy
No. of registrated element analyses = 1
NO0044.01 Bedrock
Sampler: Wilberg, R./...Stored: Løkken
Comment: Muskovittskifer med py-cpy-ga-disseminasjon.
No. of registrated element analyses = 1
NO0044.02 Bedrock
Sampler: Wilberg, R./...Stored: Løkken
Comment: Muskovittskifer med py-cpy-ga-disseminasjon.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Sample point: Prøvepunkt 1
(Object Id: 3923 11,00,01)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Mo i Rana (1927-1) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 464812 m. North: 7352047 m.
Longitude: 14.2159040 Latitude: 66.2863420
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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 Cu Kis


Fieldsamples
Sample No. Sample type Miscellanrous
NO0044.03 Bedrock
Sampler: Wilberg, R./...Stored: Løkken
Comment: Båndet hornblendegneis med po-diss.
No. of registrated element analyses = 1
NO0044.04 Bedrock
Sampler: Wilberg, R./...Stored: Løkken
Comment: Båndet hornblendegneis med po-diss.
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: 2984 11,01,00)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Mo i Rana (1927-1) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 463698 m. North: 7351615 m.
Longitude: 14.1911940 Latitude: 66.2823390
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Pb Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


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

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :213 / 19 Post-mineralisation ;...Effect :Controls

Information(s) in free text format
Free text
Det nordligste skjerpet er 15 m sør for vatnet. Det er sprengt ut 1 kbm i en skrent. Det er blottlagt en tynn sone, 10-15 cm, med pyritt/pyrrhotitt med noe sinkblende i kvarts-muskovittskifer. Fire analyser på malmsonen med bærbar XRF viste 0.05-0.85 % Cu, 0.45-4.57 % Zn, 0.19-0.51 % Pb, 3.37-6.24 % Ba.

Fieldsamples
Sample No. Sample type Miscellanrous
HAM-02 Dump
Sampler: T. Bjerkgård
Comment: po-sl mineralization in quartz-biotite schist (sample for mineralogy)

Name of Locality: Skjerp 2
(Object Id: 2985 11,02,00)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Mo i Rana (1927-1) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 463716 m. North: 7351515 m.
Longitude: 14.1916230 Latitude: 66.2814460
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Pb Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Information(s) in free text format
Free text
I vannkanten 20 m sør for hovedskjerpet er det sprengt ut 1 m3.

Name of Locality: Skjerp 3
(Object Id: 2986 11,03,00)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Mo i Rana (1927-1) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 463813 m. North: 7351393 m.
Longitude: 14.1938280 Latitude: 66.2803640
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Pb Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :125 / 20 Post-mineralisation ;...Effect :Controls

Information(s) in free text format
Free text
Utsprengt <0.5 m3 i en 15 cm mektig sulfid-disseminering i kvartsrik muskovittgneis.

Fieldsamples
Sample No. Sample type Miscellanrous
HAM-03 Bedrock
Sampler: T. Bjerkgård/...Stored: Løkken
Comment: Quartz-sericite schist with py-sl impregnation, accessory cpy
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Skjerp 4
(Object Id: 2987 11,04,00)
Location
County: Nordland Municipality: Rana (1833)
Map 1:50000: Mo i Rana (1927-1) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 463843 m. North: 7351330 m.
Longitude: 14.1945120 Latitude: 66.2798020
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Zinc
Element(s): Zn Pb Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :134 / 14 Post-mineralisation ;...Effect :Controls

Information(s) in free text format
Free text
Lite skjerp, 2 kbm tipp. Blottlagt en 20-30 cm mektig sone med dels semimassiv, båndet pyritt-sinkblende mineralisering med noe pyritt, blyglans og kobberkis.

Fieldsamples
Sample No. Sample type Miscellanrous
HAM-04 Bedrock
Sampler: T. Bjerkgård/...Stored: Løkken
Comment: Semimassive py-sl with subordinate ga and accessory cpy
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Analyse Results
from
Deposit Area 1833 - 011 Hammartjørna

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#
HAMMERTJ-01 Bedrock 3240 24800 3960 -1 9 5.0 80.0
HAM-01 Bedrock 3000 14200 2800 2 -5 2.0 30.0
HAM-03 Bedrock 2580 17900 630 3 6 2.0 80.0
HAM-04 Bedrock 1840 44300 40200 -1 -5 88.0 10.0
NO0044.01 Bedrock 565 5528 4028 7 3 4.0 33.0
NO0044.02 Bedrock 216 22026 1301 8 5 1.6 7.0
NO0044.03 Bedrock 143 5538 1922 47 199 12.5 32.0
NO0044.04 Bedrock 126 4404 1572 41 143 9.0 37.0
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sn* Sb* Bi*
HAMMERTJ-01 17 94300 49.00 3 37 8
HAM-01 6897 18.00 3
HAM-03 30723 115.00 2
HAM-04 14600 24.00 6
NO0044.01 1.0 2.0 5 26.4 26 2.00 3 15
NO0044.02 2.0 2.0 10 107.0 29 15.00 2 6
NO0044.03 2.0 5.0 5 21.1 86 3.00 13 2
NO0044.04 1.0 5.0 8 16.8 87 3.00 11 2
------------------
Sample No. S% V* Cr* Mn* Fe% Th* U* W* Sr*
HAMMERTJ-01 200 3.45 3.00 4.00
HAM-01 -10 465 9.82 4.00 4.00
HAM-03 10 232 5.53 4.00 7.00
HAM-04 -10 232 25.74 3.00 4.00
NO0044.01 8.79 1 2 113 8.01 1.00 5.00 1 14.0
NO0044.02 22.22 6 3 256 18.80 1.00 5.00 1 5.0
NO0044.03 1.93 20 54 102 3.17 1.00 5.00 5 5.0
NO0044.04 1.28 26 65 169 2.63 1.00 5.00 4 5.0
------------------
Sample No. La* B*
HAMMERTJ-01
HAM-01
HAM-03
HAM-04
NO0044.01 2.00 2
NO0044.02 2.00 2
NO0044.03 2.00 2
NO0044.04 2.00 2

The fact sheet was created on 09.05.2024
Questions or comments regarding the fact sheet can be emailed to:
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