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THE ORE DATABASE
Deposit 3014 - 002 Romsås
(Object Id: 12667)
(Last updated: 29.04.2019)

Location
County: Viken Municipality: Indre Østfold (3014)
Map 1:50000: Askim (1914-2) Map 1:250000: Oslo
Coordinate system: EU89-UTM Zone 32
East: 618975 m. North: 6607489 m.
Longitude: 11.1071620 Latitude: 59.5886590
Show on map

Resource
Resource Type: Ferroalloys (Cr,Ni,Co,V,Mo,W) Resource Subtype: Nickel
Element(s): Ni Cu Co
Importance
Raw material meaning: Little Importance (reg. 18.02.2015)
Historical: Yes , (Confirmed 29.mai.2001 by Lars Petter Nilsson)

Resources and production
Activity: Mining Reserves:
Operating method: Open pit and underground mining Historical production: 13,2 thousand tons


Products
Element/product Crude ore grade or quality Reg. date
Cu 0.4 % 20.09.2012
Ni 1.07 % 18.02.2005

Mineralization
Era: Proterozoic Period: Paleoproterozoic
Genesis: Orthomagmatic formation Form: Irregular
Main texture: Structureless Min. distribution: Semi-massive (20-50 % ore minerals)
Main grain size: Fine grained (< 1 mm) Main alteration: No country rock alteration
Strike/Dip: Direction:
Plunge:
Stratigraphic classification of host rock
Era: Proterozoic Period: Paleoproterozoic
Province: East Norwegian Basement Province
Geotec.unit: Østfold Complex
Tectonic complex:
Igneous complex:
Group: Formation:

Mineralogy
Relationship Mineral Amount
Gangue mineral Plagioclase Major mineral (>10%)
Gangue mineral Pyroxene Major mineral (>10%)
Gangue mineral Biotite Subordinate mineral (1-10%)
Gangue mineral Quartz Accessory mineral (<1%)
Ore mineral Pyrrhotite Major mineral (>10%)
Ore mineral Cobalt pentlandite Subordinate mineral (1-10%)
Ore mineral Pentlandite Subordinate mineral (1-10%)
Ore mineral Chalcopyrite Subordinate mineral (1-10%)

Lithology:
Relationship Rock Origin
Host rock diorite Intrusive
Original rock :Diorite

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Rock contact Syn-mineralisation

Information(s) in free text format
Description
Romsås The Romsås nickel deposit, though itself not impressive by size, is by far the largest of the nickel sulphide occurrences in Indre Østfold. It is situated within a minor quartz noritic body of assumed Mesoproterozoic age surrounded by migmatitic gneisses of presumed sedimentary origin on the regional map of Berthelsen et al. (1996) interpreted as Mesoproterozoic greywacke-dominated metasediments (Bingen et al. 2005). Neither the Romsås body, nor any of the other nickel sulphide ore-bearing mafic bodies in Østfold, are dated to the knowledge of the present writer. Therefore, the 1555 +3/-2 Ma Follum dioritic intrusion in the Begna sector in the NW is the one closest comparable both in space and time to the mafic intrusions in Indre Østfold. The Romsås deposit is most famous for its orbicular norite, developed mostly along the western margin of the intrusion, but also in the inner parts of the body. The orbicular norite is partly cut by the sulphide ore zones and is partly cutting these (Støren 1909). No exhaustive modern studies are undertaken on the Romsås body with its sulphide mineralization, but a wealth of classic works, mainly descriptive, both on this one and other nickel bearing intrusions in Norway exist from professor Vogt and other Norwegian pioneer geologists. The most recent description of Romsås is that found in the review paper by Boyd & Nixon (1985).
Historical significance
History of mining The company Roms Nikkelverk (Roms Nickelworks) commenced mining on the Romsås deposit in 1866 and kept a continuous activity running until the nickel crack in 1876. During the first seven years only test mining was carried out. In 1873 full-scale mining started, and that year the company also built its own smelter (Meinich 1879). In 1875 all together 122 men were employed at the company, 74 at the mines (i.e. the main mine at Romsås and a much smaller mine at Frøland), and 48 at the smelter (Helland 1900). After the big nickel crack in 1876 the Romsås deposit closed down and never came into production again. Total ore production from the Romsås deposit accumulated to 13 205 tons with a nickel content of c. 125 - 130 tons. Total production from all the company's mines during the period 1866-76 was, according to official statistics, 16 465 tons with a Ni content of c. 150 tons. The average ore grade at Romsås was 1.07 % Ni (+ Co) and 0.4 % Cu (Vogt 1902, Meinich & Vogt 1903). Pyrrhotite, pentlandite and chalcopyrite constitute the main ore minerals in the Romsås ore, whereas pyrite constitutes a rare, secondary constituent according to Meinich (l879, p. 128).

Bibliography:
From NGU's Reference Archive:
Carstens, Harald , 1957
On the orbicular structure in the norite of Romsaas, Norway.
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.37 (2);279-280 pages
Abstract:
Frie emneord: Noritt

Egeberg, K. , 1902
Romsås grube. Geologisk plankart med daganlegg 1:1 000.
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 1089

Andresen, Unni ; Sørlie, Thor , 2009
Romsåsen gruver
;Norske Amatørgeologers Sammenslutning (NAGS);ARTIKKEL;Stein; No.36 (2);20-25 pages
Abstract:

Singsaas, Per , 1974
Geofysiske målinger Romsås grube.
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.1221;7 pages

Boyd, R.; Nixon, F. , 1985
Norwegian nickel deposits: a review.
;Geologian Tutkimuskeskus / Geological Survey of Finland;ARTIKKEL;Bulletin; Nickel-copper deposits of the Baltic Shield and Scandinavian; Caledonides.; No.333;363-394 pages

Meinich, L. , 1903
Les qisements de nickel de Romsaas, Smaalene, Norvege.
;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 1428;8 pages
Abstract:
Rapporten beskriver: - tidligere drift (inkl. tonnasje og gehalt) - forekomstens beliggenhet - geologien (malmens utbredelse, mektighet, malmtype og opptreden) - framtidige undersøkelser.

Thorkildsen, Birger , 1913
Rapport over Romsaas Gruber.
;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 4045;2 pages
Abstract:
Forekomstene i Romsåsen ligger på kontakten mellom gneis og noritt. Mot gneisen finnes først kulenoritt og innenfor denne forekommer malmen. Malmen består for en stor del av impregnassjonsmalm. En rekke paralelle malmsoner ser ut til å stå vinkelrett på kontakten. Orter og synker er drevet på sonene. I et parti under den dypeste stollen inneholder malmen 3% nikkel og kobolt. Norittfeltet er lite i forhold til feltene i Evje. Det er tidliger brudt 16 465 tonn malm i gruven, man fikk da 1,08 tonn pr. m3 med en nettogehalt på 1,07% Ni og 0,4% Cu.

Berthelsen, Asger; Olerud, Svein; Sigmond, Ellen M.O.; Sundvoll, Bjørn , 1996
Oslo. Berggrunnskart Oslo M 1:250 000; trykt i farger
;Norges geologiske undersøkelse;KART;1 kart pages
Abstract:
Beskrivelsen finnes på kartet.

Bingen, Bernard; Skår, Øyvind; Marker, Mogens; Sigmond, Ellen M. O.; Nordgulen, Øystein; Ragnhildstveit, Jomar; Mansfeld, Joakim; Tucker, Robert D.; Liegeois, Jean Paul , 2005
Timing of continental building in the Sveconorwegian orogen, SW Scandinavia
;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.85(1/2);87-105 pages
Abstract:
The timing of continental building in the Sveconorwegian orogen of SW Scandinavia is evaluated with zircon U-Pb geochronology. ID-TIMS, LA-ICPMS and SIMS data are reported for 21 samples of orthogneiss, metahyolite and metasandstone in S Norway, with emphasis on the Suldal area. The Sveconorwegian orogen is divided into a reworked Fennoscandian 1,80-1,64 GA parautochtonous segment, the Eastern Segment, and two allochtthonous terranes. The Idefjorden terrane is interpreted as a compsite 1.66-1.52 Ga arc formed at the margin or near the margin of Fennoscandia. The western terrane, including the Telemark, Hardangervidda, Suldal and Rogaland - Vest Agder sectors, is named Telemarkia. U-BPb zircon data indicate that Telemarkia was built during a short magmatic event between 1.52 and 1.48 Ga, and was located at the margin of a Palaeoproterozoic craton, possibly Fennoscandia. No basement older than 1.5 Ga can be positively identified. In the early stage of the Sveconorwegian orogeny, Telemarkia collided with the Idefjorden terrane. The Bamble-Kongsberg sector, characterized by a mixed lithology and 1.13-1.10 Ga early-Sveconorwegian high-grade metamorphism, is interpreted as the original collision zone between these terranes.

Helland, Amund , 1901
Bergverksdrift og stenbrydning i Norge
;ARTIKKEL;Naturen; No.25. aarg.;51-75 pages
Abstract:
Artikkel fortsetter på s. 96-103 i samme årgang

Støren, R. , 1909
Romsås grube. Geologisk gruvekart i plan og profil, 1:1 000.
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 1087

Støren, R. , 1909
Romsås grube. Geologisk gruvekart i plan og profil, 1:500.
;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 1086 A-E

Fieldsamples
Sample No. Sample type Miscellanrous
ROMSAS99-1 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-2 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-3 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-4 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-5 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-6 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-7 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
ROMSAS99-8 Dump
Sampler: Lars Petter Nilsson
Comment: Utplukket malm fra tippen
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:


Analyse Results
from
Deposit Area 3014 - 002 Romsås

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#
ROMSAS99-1 Dump 2900 7 2 1300 20000 -.5 15.0
ROMSAS99-2 Dump 12900 22 4 1100 17400 1.7 48.0
ROMSAS99-3 Dump 3400 16 3 1200 14200 .6 8.0
ROMSAS99-4 Dump 3800 21 3 1100 13900 .7 9.0
ROMSAS99-5 Dump 13100 51 3 495 7830 2.6 27.0
ROMSAS99-6 Dump 35300 99 6 466 11600 7.2 56.0
ROMSAS99-7 Dump 3506 27 2 473 8479 .6 18.0
ROMSAS99-8 Dump 2509 27 1 302 3812 .6 77.0
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sb* Bi* Se*
ROMSAS99-1 15.0 103.0 -5 -.5 7 3.00 -1 2 60.00
ROMSAS99-2 12.0 70.0 -5 -5.0 9 2.40 -1 2 50.00
ROMSAS99-3 3.0 40.0 -5 -.5 11 2.40 -1 3 53.00
ROMSAS99-4 8.0 43.0 -5 -.5 11 2.40 -1 3 49.00
ROMSAS99-5 7.0 35.0 -1 .2 29 1.80 -0 1 20.20
ROMSAS99-6 20.0 26.0 -1 .7 6 1.80 0 0 26.20
ROMSAS99-7 5.0 25.0 -1 .1 51 1.80 -0 0 17.90
ROMSAS99-8 4.0 18.0 -1 .1 25 1.10 -0 1 12.80
------------------
Sample No. S% V* Cr* Mn* Fe% Th* U* Sr* La*
ROMSAS99-1 27.90 18 78 22 41.39 -0.50 -0.50 -5.0 -0.50
ROMSAS99-2 24.90 21 123 26 34.76 -0.50 -0.50 -5.0 0.50
ROMSAS99-3 26.10 17 85 65 39.79 -0.50 -0.50 -5.0 0.60
ROMSAS99-4 24.60 17 95 72 38.61 -0.50 -0.50 -5.0 0.50
ROMSAS99-5 9.67 17 166 417 21.05 0.30 0.10 6.0 3.00
ROMSAS99-6 9.99 35 302 107 22.80 0.60 0.20 2.0 3.00
ROMSAS99-7 8.25 25 247 169 16.97 0.60 0.10 11.0 6.00
ROMSAS99-8 6.48 32 308 172 11.99 0.30 0.20 8.0 3.00
------------------
Sample No. Na* Mg* Al* P* K * Ca* Ti* Hg*
ROMSAS99-1 -100 0 1300 40 200 300 100 0
ROMSAS99-2 -100 0 1900 130 300 400 200 -0
ROMSAS99-3 100 0 1200 100 200 400 100 0
ROMSAS99-4 100 1 1400 120 200 600 100 0
ROMSAS99-5 280 1 2900 340 700 2400 300 0
ROMSAS99-6 150 1 6100 280 2100 2000 630 0
ROMSAS99-7 550 1 4900 560 1900 3800 800 0
ROMSAS99-8 480 1 5000 640 2300 3300 860 0


The fact sheet was created on 26.10.2021

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