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THE ORE DATABASE
Occurence 5021 - 001 Skardøla
(Object Id: 4204)
(Last updated: 10.09.1999)
Location
County: Trøndelag Municipality: Oppdal (5021)
Map 1:50000: Oppdal (1520-3) Map 1:250000: Røros
Coordinate system: EU89-UTM Zone 32
East: 534960 m. North: 6942539 m.
Longitude: 9.6811760 Latitude: 62.6119540
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Resource
Resource Type: Ferrous metals(Fe, Mn, Ti) Resource Subtype: Iron
Element(s): Fe Kis
Importance
Raw material meaning: Not Assessed (reg. 18.02.2015)

Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Operations
From - To Activity Comments
1997 - 1997 Sampling Company/Institution :NGU-malmreg.

Mineralization
Genesis: Volcex Form:
Main texture: Porphyroblastic Min. distribution: Semi-massive (20-50 % ore minerals)
Main grain size: Very unevenly grained Main alteration:
Strike/Dip: 300 / 10 Direction:
Plunge:
Stratigraphic classification of host rock
Era: Period:
Province: Caledonides
Geotec.unit: Trondheim Nappe Complex
Tectonic complex: Støren Nappe
Igneous complex:
Group: Støren Formation:

Mineralogy
Relationship Mineral Amount
Gangue mineral Amphibole Major mineral (>10%)
Gangue mineral Quartz Subordinate mineral (1-10%)
Gangue mineral Feldspar Subordinate mineral (1-10%)
Ore mineral Pyrite Major mineral (>10%)
Ore mineral Magnetite Major mineral (>10%)
Ore mineral Chalcopyrite Accessory mineral (<1%)
Ore mineral Galena Accessory mineral (<1%)

Lithology:
Relationship Rock Origin
Host rock Chert Sedimentary
Original rock :Exhalite
Metamorphic facies :Greenschist
Host rock Greenstone Extrusive
Original rock :Basalt
Metamorphic facies :Greenschist

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :300 / 10 Post-mineralisation ;...Effect :None

Information(s) in free text format
Description
Mineraliseringen har utgående vest for skiheis og alpinløyper, 980 m.o.h. i Skjørstadhovden. Den er nevnt under forskjellige navn: Skjørdøla (Nilsen 1978), Aune (Bergarkivet) og, i mutingsbrev av 9/6-1951, "Gråbergene" i Skjørstadhovden. I det lille skjerpet (utsprengt 1 m3) er det en minst 1.10 m mektig stratabunden sulfid-oksyd-mineralisering i grønnstein med et par tynne cherthorisonter. I den finkornige grønnsteinen opptrer opptil 15 mm store, euhedrale svovelkiskrystaller som tildels er anriket i lag. Svovelkisporfyroblastene har ofte en mørk kjerne av sannsynligvis amfibol. Det fins også tilnærmet konkordante, mm-cm-mektige, bånd av finkornig svovelkis, og tynne, mer uregelmessige svovelkisårer. Magnetitt som anhedrale "kuler" opptrer disseminert i det meste av mineraliseringen, men er anriket i minst 2 lag av chert/jaspis (5-10 cm mektige) med finkornig, semimassiv til massiv magnetitt. Foliasjon: 300/10. Mineraliseringen dreier av mot NØ, videre oppover mot en liten topp, og smalner av til 20-40 cm mektighet. Retningen her er 220/40. Videre mot NØ synes den å dø ut og gå over i en mørkegrå, silifisert skifer. Vest for skjerpet forsvinner mineraliseringen etter få meter under overdekke. Tilsammen kan den følges over 60-70 m lengde.

Bibliography:
From NGU's Reference Archive:
Nilsen, Odd , 1978
Caledonian sulphide deposits and minor iron-formations from the southern Trondheim region, Norway.
;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.340;35-85 + k pages
Abstract:
Within the southern and central parts of the Trondheim region of the Norwegian Caledonides a great number of small, stratabound cupriferous pyrite deposits are confined to mafic metavolcanics of the Gula, Støren and Fundsjø Groups of the Lower Palaeozoic succession. The deposits occuring within, or in close contact with the metavolcanics are characterized by their association with minor manganiferous oxide/silicate iron-formations - better known as "vasskis" ore type - within the metamorphic low-grade areas. The iron-fprmations of the metamorphic higher grade terrains on the other hand, which are extensively developed within the Gula Group, are mostly of a pyrrhotitic sulphide/silicate type and sulphurization processes are thought to have played an important role during the metamorphism. The pyrite deposits occurring adjacent to the metavolcanics bear no relationship to the iron-formations. They are embedded in pelitic, often carbonaceous assemblages (Gula Group) or within tuffitic members of the volcanogene Støren Group, and they are thought to represent re-sedimented (reworked) deposits. The pyrite deposits display varying degree of metamorphic reconstitution and a tectonic control has apparently determined their disc- or ruler-shaped morphology.

Fieldsamples
Sample No. Sample type Miscellanrous
ST0001.01 Dump
Sampler: Wilberg/...Stored: Løkken
Comment: Chert med fink. semimassiv mt-min.
No. of registrated element analyses = 1
ST0001.02 Dump
Sampler: Wilberg/...Stored: Løkken
Comment: Grønnstein med py-porfyroblaster og mt-diss.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Analyse Results
from
Deposit Area 5021 - 001 Skardøla

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#
ST0001.01 Dump 3 61 10 6 12 .4 1.0
ST0001.02 Dump 105 130 268 172 142 .4 6.0
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sb* Bi* S%
ST0001.01 7.0 9.0 -2 -.2 5 3.00 -3 -3 -.01
ST0001.02 8.0 8.0 213 .2 22 53.00 -3 -3 16.80
------------------
Sample No. V* Cr* Mn* Fe% Th* U* W* Sr* La*
ST0001.01 185 46 1233 32.10 11.00 -8.00 -2 7.0 22.00
ST0001.02 97 36 1469 22.78 8.00 -8.00 -2 3.0 9.00
------------------
Sample No. B*
ST0001.01 -3
ST0001.02 3

The fact sheet was created on 05.05.2024
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