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THE ORE DATABASE
Occurence 1824 - 002 Gåstjønna
(Object Id: 2151)
(Last updated: 28.04.2020)

Location
County: Nordland Municipality: Vefsn (1824)
Map 1:50000: Elsfjord (1927-3) Map 1:250000: Mo i Rana
Coordinate system: EU89-UTM Zone 33
East: 436544 m. North: 7332402 m.
Longitude: 13.5959830 Latitude: 66.1057030
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Resource
Resource Type: Ferrous metals(Fe, Mn, Ti) Resource Subtype: Iron
Element(s): Fe
Importance
Raw material meaning: Little Importance (reg. 18.02.2015)

Resources and production
Activity: Exploration Reserves: 1125 thousand tons
Operating method: Historical production:


Products
Element/product Crude ore grade or quality Reg. date
Fe-mag. 10 % 04.01.1993
Fe-total 19 % 04.01.1993

Operations
From - To Activity Comments
1975 - 1975 Geology Company/Institution :Rana Gruber

Mineralization
Era: Proterozoic Period: Neoproterozoic
Genesis: Sedex Form: Layer
Main texture: Banded Min. distribution: Semi-massive (20-50 % ore minerals)
Main grain size: Fine grained (< 1 mm) Main alteration:
Strike/Dip: 355 / 80 Direction: 225
Plunge: 40
Stratigraphic classification of host rock
Era: Proterozoic Period: Neoproterozoic
Province: Caledonides
Geotec.unit: Helgeland Nappe Complex
Tectonic complex: Øverste allokton
Igneous complex:
Group: Elsfjordgruppen Formation: Jernformasjonen

Mineralogy
Relationship Mineral Amount
Gangue mineral Epidote Major mineral (>10%)
Gangue mineral Amphibole Major mineral (>10%)
Gangue mineral Quartz Major mineral (>10%)
Gangue mineral Chlorite Subordinate mineral (1-10%)
Gangue mineral Carbonate Subordinate mineral (1-10%)
Gangue mineral Biotite Subordinate mineral (1-10%)
Gangue mineral Apatite Accessory mineral (<1%)
Ore mineral Magnetite Major mineral (>10%)
Ore mineral Hematite Subordinate mineral (1-10%)

Lithology:
Relationship Rock Origin
Unknown Staurolitt-granatgl.sk. Sedimentary
Original rock :Argillaceous sediment
Metamorphic facies :Amphibolite
Unknown Amfibolitt Extrusive
Original rock :Basalt
Metamorphic facies :Amphibolite

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Unknown Primary layering Strike/Dip :45 / 80 Syn-mineralisation ;...Effect :None

Information(s) in free text format
Free text
The Gåstjønna IF is supposed to represent the same horizon as at Seljeli. It is partly enclosed by the Nilsfjellet quartz diorite. The IF is exposed along a steep minor waterfall east of Gåstjønna. The IF is steep dipping and about 15 m thick and comprises both massive and disseminated magnetite in amphibole and epidote rich matrix that commonly is finely banded. Four samples were collected across the sequence (Samples JS_FE1732-35). Hematite-rich horizons as in Seljeli were not observed. On top of the waterfall occurs medium-grained garnet-mica schist. Both the IF and schist is crosscut by several felsic dykes.

Bibliography:
From NGU's Reference Archive:
Bøckman, K.L. , 1947
Seljeli jernmalmforekomster i Elsfjord.
;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 1986;5 pages
Abstract:
Lokalitetsnummer forts.: 40456, 40458 - 40460 Rapporten er en brevkopi og omhandler Seljeli jernmalmforekomster. Det blir referert til magnetometerundersøkelser og gitt en detaljert beskrivelse av nødvendige undersøkelsesarbeider av forekomsten. Det er også utført malmberegninger og driftsoverslag.

Fieldsamples
Sample No. Sample type Miscellanrous
JS_FE1732 Bedrock
Sampler: J.S. Sandstad
Comment: Magnetite dissemination in amphibolitic rock
No. of registrated element analyses = 1
No. of registrated oxide analyses = 1
JS_FE1733 Bedrock
Sampler: J.S. Sandstad
Comment: Finely banded magnetite-amphibole-epidote rock
No. of registrated element analyses = 1
No. of registrated oxide analyses = 1
JS_FE1734 Bedrock
Sampler: J.S. Sandstad
Comment: Finely banded magnetite-amphibole-epidote rock
No. of registrated element analyses = 1
No. of registrated oxide analyses = 1
JS_FE1735 Bedrock
Sampler: J.S. Sandstad
Comment: Finely banded magnetite-amphibole-epidote rock
No. of registrated element analyses = 1
No. of registrated oxide analyses = 1
NB! All analyse values are shown at the end of the printout.:


Analyse Results
from
Deposit Area 1824 - 002 Gåstjønna

Element analyses

( *=parts pr. million, #=parts pr.billion, Negative values means below detection limit value.)
Sample No. Sample Type Cu* Zn* Pb* Co* Ni* Au# As*
JS_FE1732 Bedrock 4 18 1 10 11 2.0 -1
JS_FE1733 Bedrock 3 22 2 11 14 2.4 1
JS_FE1734 Bedrock 2 17 1 13 15 1.6 1
JS_FE1735 Bedrock 3 19 2 13 15 2.3 -1
------------------
Sample No. Ba* Mo* Sn* Se* Ga* V* Th* U* W*
JS_FE1732 199 0.30 1 -0.50 8.60 110 5.20 0.80 -1
JS_FE1733 60 0.50 1 -0.50 8.40 95 5.10 0.60 -1
JS_FE1734 26 0.50 -1 -0.50 4.30 75 2.90 0.70 -1
JS_FE1735 158 0.40 2 -0.50 9.80 113 5.90 1.10 1
------------------
Sample No. Rb* Sr* Y* Zr* Nb* Ta* Cs* La* Ce*
JS_FE1732 22.9 249.5 26.6 107 8.20 0.40 0.10 21.20 50.00
JS_FE1733 34.1 189.2 22.8 98 9.50 0.60 0.20 24.10 51.20
JS_FE1734 1.9 221.0 20.1 57 6.80 0.30 -0.10 13.90 29.50
JS_FE1735 22.1 323.5 24.8 120 12.20 0.70 0.10 30.50 64.20
------------------
Sample No. Pr* Nd* Sm* Eu* Gd* Tb* Dy* Ho* Er*
JS_FE1732 5.65 21.90 4.67 1.15 4.61 0.74 4.36 0.95 2.80
JS_FE1733 5.80 22.50 4.41 1.08 4.16 0.66 4.03 0.82 2.54
JS_FE1734 3.24 13.10 2.46 0.66 2.70 0.44 2.95 0.66 2.12
JS_FE1735 7.08 26.30 5.21 1.24 5.09 0.74 4.52 0.91 2.66
------------------
Sample No. Tm* Yb* Lu* Be* Hf*
JS_FE1732 0.38 2.56 0.38 -1 2.90
JS_FE1733 0.35 2.23 0.37 -1 2.40
JS_FE1734 0.31 2.05 0.32 -1 1.30
JS_FE1735 0.37 2.46 0.37 -1 3.10

Oxide analyses

( All values are in % )
Sample No. Sample Type SiO2 Al2O3 TiO2 Fe2O3 MnO MgO CaO
JS_FE1732 Bedrock 45.60 7.85 0.62 29.90 0.11 4.42 8.22
JS_FE1733 Bedrock 45.80 6.73 0.55 29.10 0.18 5.05 10.40
JS_FE1734 Bedrock 33.30 3.50 0.32 42.50 0.65 5.67 13.10
JS_FE1735 Bedrock 44.60 8.31 0.72 23.00 0.20 6.47 13.90
------------------
Sample No. Na2O K2O P2O5 Loss Sum
JS_FE1732 1.03 1.21 0.51 -0.44 99.00
JS_FE1733 0.65 1.16 0.35 -0.41 100.00
JS_FE1734 0.39 0.13 0.41 -0.76 99.00
JS_FE1735 0.91 1.10 0.37 0.03 100.00


The fact sheet was created on 29.03.2024

Questions or comments regarding the fact sheet can be emailed to:
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