Norsk versjon
THE ORE DATABASE
Occurence 5032 - 012 Røsbekken
(Object Id: 4485)
(Last updated: 05.07.2023)
Location
County: Trøndelag Municipality: Selbu (5032)
Map 1:50000: Stjørdal (1621-1) Map 1:250000: Trondheim
Coordinate system: EU89-UTM Zone 32
East: 603390 m. North: 7020890 m.
Longitude: 11.0627550 Latitude: 63.3019030
Show on map
Resource
Resource Type: Ferrous metals(Fe, Mn, Ti) Resource Subtype: Iron
Element(s): Fe Kis
Importance
Raw material meaning: Little Importance (reg. 18.02.2015)

Resources and production
Activity: Test mining Reserves:
Operating method: Open pit and underground mining Historical production:


Mineralization
Era: Paleozoic Period: Ordovician
Genesis: Volcex Form: Layer
Main texture: Structureless Min. distribution: Semi-massive (20-50 % ore minerals)
Main grain size: Fine grained (< 1 mm) Main alteration:
Strike/Dip: 350 / 45 Direction:
Plunge:
Stratigraphic classification of host rock
Era: Paleozoic Period: Ordovician
Province: Caledonides
Geotec.unit: Trondheim Nappe Complex
Tectonic complex: Gula Complex
Igneous complex:
Group: Formation:

Mineralogy
Relationship Mineral Amount
Gangue mineral Quartz Major mineral (>10%)
Gangue mineral Siderite Subordinate mineral (1-10%)
Ore mineral Magnetite Major mineral (>10%)
Ore mineral Pyrrhotite Subordinate mineral (1-10%)
Ore mineral Arsenopyrite Subordinate mineral (1-10%)
Ore mineral Pyrite Accessory mineral (<1%)

Lithology:
Relationship Rock Origin
Host rock Banded quartzite Sedimentary
Original rock :Exhalite
Metamorphic facies :Greenschist
Wall rock Metagrewacke Sedimentary
Original rock :Greywacke
Metamorphic facies :Greenschist

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Wall rock Schistosity Strike/Dip :310 / 40 Post-mineralisation

Information(s) in free text format
Free text
Røsbekken ligger nord for gården Røsåsen. Enkel adkomst er via Espvegen opp til gården og langs en traktorvei derfra fram til bekken. Forekomsten er godt skiltet, og en plakat med informasjon om bergarter og jernmalmer i Strandfjellet er satt opp. Gruva ble drevet av Mostadmark jernverk på midten av 1800-tallet. Forekomsten ligger 20 m nord for brua over Røsbekken og består av en 5x5 m vannfylt skråsynk og en opptil 4 m høy skjæring langs vestsida av en knaus. En 0,5 m mektig sone med massiv magnetitt ligger i nedre del av skjæringen og over denne finnes båndet, kvartsitt med slirer og tynne bånd med magnetitt. Totalt er den magnetitt-førende sona ca. 3 m mektig. Over denne dominerer disseminasjon og slirer/bånd av finkornet magnetkis og arsenkis (dels som 4-5 mm lange nåler) i kvartsitten. Denne kan følges få ti-talls meter videre nordover langs knausen. Analyse av arsenkis-mineraliseringen gir 2 g/t gull. Flere årer og ganger med kvarts gjennomsetter kvartsitten og skifrig metagråvakke ligger under den. Tippen er dels utplanert for traktorveien og gjengrodd ned mot bekken.

Bibliography:
From NGU's Reference Archive:
Torske, Tore , 1965
Geology of the Mostadmarka and Selbustrand area, Trøndelag.
;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.232;1-83 + ka pages
Abstract:
The bedrock of the area consists of metamorphic epiclastic, volcanic, and intrusive rocks of assumed Lower Ordovician age, assigned to, and lithologically matching the rocks of, the Røros, Støren and Lower Hovin Groups of the Trondheim Region. A detailed petrographic description of the rock varieties is given. The metamorphic grade of all rocks corresponds to the Greenschist Facies. - Small ore deposits occur in connection with the volcanic rocks. They comprise pyrite-pyrrhotite ores of the Leksdal Type, mixed pyrite-magnetite ores, and iron oxide ores. - Lithological variations of the sedimentary rocks is tentatively correlated with events during the early periods of the Caledonian Orogeny. - The volcanism within the area seems to have started with a phase of explosive activity, followed by extrusion (mostly submarine) of copious amounts of spilitic lavas; towards the end of the main period of volcanism a new episode of explosive activity has produced what is called the upper pyroclastic horizon, comprising rocks ranging from coarse volcanic breccia to finegrained tuffs. - The intrusive rocks consist mainly of saussurite gabbros and quartz keratophyres. The latter are thought to be intrusive rather than effusive, and evidence is offered to support this. In some places the character of pyroclastic material points to a quartz keratophyre parentage. Thus, quartz keratophyres may have occurred both as intrusive and volcanic rocks.

Fieldsamples
Sample No. Sample type Miscellanrous
Røsbekken-1 Bedrock
Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2
Comment: Massive, fine-grained, banded magnetite, rusty (footwall)
No. of registrated element analyses = 1
No. of registrated oxide analyses = 1
Røsbekken-2 Bedrock
Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2
Comment: Massive, fine-grained, magnetite
No. of registrated element analyses = 1
No. of registrated oxide analyses = 1
Røsbekken-3 Bedrock
Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2
Comment: Arsenopyrite-pyrrhotite disseminated in quartzite
No. of registrated element analyses = 1
ST0283.01 Dump
Sampler: Størseth, L.R./...Stored: Løkken
Comment: Båndet mt-malm i bergart som varierer fra blåkvarts til ubestemmelig kvartsitt. I en av prøvene er mt båndet sammen med sideritt. Svært lavt kisinnhold.
ST0283.02 Dump
Sampler: Størseth, L.R./...Stored: Løkken
Comment: Semimassiv aspy-po-malm med 1-2 mm store aspy-xx i kvartsrik bergart med noe kloritt (sprekkeflater). Denne malmen er meget sjelden på tippen.
ST0283.03 Bedrock
Sampler: Størseth, L.R./...Stored: Løkken
Comment: Disseminert po-aspy-malm i kvartsitt. Finfordelt po lager tynne mørke striper i bergarten, aspy mer ansamlet i korngrupper, opptil 7-8 mm store.
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Røsbekken 2
(Object Id: 37493 12,01,00)
Location
County: Trøndelag Municipality: Selbu (5032)
Map 1:50000: Stjørdal (1621-1) Map 1:250000: Trondheim
Coordinate system: EU89-UTM Zone 32
East: 603418 m. North: 7020790 m.
Longitude: 11.0632490 Latitude: 63.3009980
Show on map
Resource
Resource Type: Ferrous metals(Fe, Mn, Ti) Resource Subtype: Iron
Element(s): Fe Kis
Resources and production
Activity: Exploration Reserves:
Operating method: Historical production:


Mineralogy
Relationship Mineral Amount
Gangue mineral Quartz Major mineral (>10%)
Ore mineral Pyrrhotite Major mineral (>10%)
Ore mineral Pyrite Subordinate mineral (1-10%)

Lithology:
Relationship Rock Origin
Wall rock Metagreywacke Sedimentary
Original rock :Greywacke
Metamorphic facies :Greenschist

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Wall rock Foliation Strike/Dip :305 / 40 Post-mineralisation ;...Effect :Modifies

Information(s) in free text format
Free text
Ca. 100 m sør for hovedforekomsten går bekken i et mindre stryk på tvers av strøket. Både båndet kvartsitt og skifrig metagråvakke er blottet, men magnetitt-sonen ble ikke påvist. En 20-30 cm mektig sone med massiv, finkornet magnetkis og noe pyritt ble imidlertid prøvetatt.

Fieldsamples
Sample No. Sample type Miscellanrous
Røsbekken-4 Bedrock
Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2
Comment: Massive, fine-grained, banded pyrrhotite+pyrite
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Røsbekken 3
(Object Id: 37494 12,02,00)
Location
County: Trøndelag Municipality: Selbu (5032)
Map 1:50000: Stjørdal (1621-1) Map 1:250000: Trondheim
Coordinate system: EU89-UTM Zone 32
East: 603456 m. North: 7020727 m.
Longitude: 11.0639860 Latitude: 63.3004300
Show on map
Resource
Resource Type: Ferrous metals(Fe, Mn, Ti) Resource Subtype: Iron
Element(s): Fe Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Mineralogy
Relationship Mineral Amount
Gangue mineral Quartz Major mineral (>10%)
Ore mineral Magnetite Major mineral (>10%)
Ore mineral Pyrite Subordinate mineral (1-10%)

Lithology:
Relationship Rock Origin
Host rock Banded quartzite Sedimentary
Original rock :Exhalite
Metamorphic facies :Greenschist

Information(s) in free text format
Free text
Et mindre, vannfylt skjerp ligger på østsida av bekken ca. 180 m SSØ for hovedforekomsten. Malmsonen er blottet lengst nordvest i skjerpet og er ca. 0,5 m mektig. Den består av finkornet semi-massiv magnetitt i kvartsittisk bergart

Fieldsamples
Sample No. Sample type Miscellanrous
Røsbekken-5 Bedrock
Sampler: J.S.Sandstad/...Stored: Løkken/...Size(kg): 2
Comment: Semi-massive magnetite and disseminated arsenopyrite in quartzitic 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 5032 - 012 Røsbekken

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#
Røsbekken-1 Bedrock 13 30 4 5 17 -.1 1.0
Røsbekken-2 Bedrock 9 17 2 3 21 -.1 1.0
Røsbekken-3 Bedrock 34 32 2 2 12 .2 1980.0
Røsbekken-4 Bedrock 333 562 153 19 254 2.1 209.0
Røsbekken-5 Bedrock 74 51 9 18 21 -.1 14.7
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sn* Sb* Bi*
Røsbekken-1 2 -.1 96 4.80 -1 2 -0
Røsbekken-2 1 -.1 149 1.80 -1 1 -0
Røsbekken-3 -5.0 2.0 10000 .1 30 1.65 -0 12 0
Røsbekken-4 6.0 7.0 344 2.1 60 133.00 1 77 1
Røsbekken-5 7 -.1 2291 2.10 -1 1 -0
------------------
Sample No. Se* Ga* Ge* In* S% V* Cr* Mn* Fe%
Røsbekken-1 -0.50 4.80 .04 52 27.05
Røsbekken-2 -0.50 3.30 .02 62 20.75
Røsbekken-3 3.00 1.06 -0.05 0.02 3.27 17 13 513 7.08
Røsbekken-4 7.00 5.36 0.06 0.05 10.00 138 23 483 40.80
Røsbekken-5 -0.50 6.10 .98 48 26.34
------------------
Sample No. Th* U* W* Rb* Sr* Y* Zr* Nb* Ta*
Røsbekken-1 0.20 0.60 1 0.6 175.7 4.1 6 1.00 -0.10
Røsbekken-2 -0.20 0.50 -1 0.6 289.6 3.1 5 1.10 -0.10
Røsbekken-3 0.04 0.20 0 1.3 5.0 1.1 1 0.10 -0.05
Røsbekken-4 2.88 8.80 1 18.2 19.6 5.5 33 0.70 0.05
Røsbekken-5 0.90 0.60 2 6.8 520.6 6.3 13 2.20 -0.10
------------------
Sample No. Cs* La* Ce* Pr* Nd* Sm* Eu* Gd* Tb*
Røsbekken-1 0.10 1.80 3.70 0.42 1.70 0.39 0.11 0.47 0.09
Røsbekken-2 0.30 2.70 2.80 0.39 1.60 0.31 0.09 0.41 0.07
Røsbekken-3 0.09 0.50 0.69
Røsbekken-4 1.13 8.90 18.75
Røsbekken-5 0.60 5.30 10.90 1.05 3.90 0.86 0.25 0.89 0.15
------------------
Sample No. Dy* Ho* Er* Tm* Yb* Lu* Li* Be* Na*
Røsbekken-1 0.59 0.13 0.50 0.08 0.60 0.10 -1
Røsbekken-2 0.46 0.10 0.33 0.04 0.24 0.04 1
Røsbekken-3 2 0 100
Røsbekken-4 10 0 500
Røsbekken-5 0.97 0.23 0.70 0.11 0.67 0.10 3
------------------
Sample No. Mg* Al* P* K * Ca* Sc* Ti* Te* Hf*
Røsbekken-1 218 0.10
Røsbekken-2 305 -0.10
Røsbekken-3 700 1300 90 300 1200 0.50 -50 0.72 -0.10
Røsbekken-4 1900 14800 560 4900 2000 4.20 320 0.74 0.80
Røsbekken-5 305 0.30
------------------
Sample No. Re* Hg* Tl*
Røsbekken-1 -0 -0
Røsbekken-2 -0 -0
Røsbekken-3 0 0
Røsbekken-4 0 0
Røsbekken-5 -0 -0

Oxide analyses
( All values are in % )
Sample No. Sample Type SiO2 Al2O3 TiO2 Fe2O3 MnO MgO CaO
Røsbekken-1 Bedrock 56.09 0.67 0.02 38.67 1.26 0.14 0.40
Røsbekken-2 Bedrock 68.20 0.39 0.02 29.66 0.17 0.08 0.43
Røsbekken-5 Bedrock 39.73 1.29 0.06 37.66 5.00 0.50 3.49
------------------
Sample No. Na2O K2O P2O5 Sum
Røsbekken-1 0.34 -0.01 0.05 98.00
Røsbekken-2 0.19 -0.01 0.07 99.00
Røsbekken-5 0.05 0.15 0.07 88.00

The fact sheet was created on 04.05.2024
Questions or comments regarding the fact sheet can be emailed to:
ressursdatabaser@ngu.no
Copyright © 2024 Geological Survey of Norway