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THE ORE DATABASE
Occurence 5043 - 037 Borvatnet
(Object Id: 278)
(Last updated: 16.02.2005)
Location
County: Trøndelag Municipality: Raarvihke (5043)
Map 1:50000: Jomafjellet (1924-1) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 439881 m. North: 7188173 m.
Longitude: 13.7339350 Latitude: 64.8126300
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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
1991 - 1991 Sampling Company/Institution :NGU
1996 - 1996 Sampling Company/Institution :NGU

Mineralization
Era: Paleozoic Period: Ordovician
Genesis: Volcex Form: Layer
Main texture: Banded Min. distribution: Massive (>50 % ore minerals)
Main grain size: Fine grained (< 1 mm) Main alteration: Epidotisation
Strike/Dip: 40 / 20 Direction:
Plunge:
Stratigraphic classification of host rock
Era: Paleozoic Period: Ordovician
Province: Caledonides
Geotec.unit: Køli Nappe Complex
Tectonic complex: Gjersvik Nappe
Igneous complex:
Group: Limingen Formation: Devikgrønnstein

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

Lithology:
Relationship Rock Origin
Wall rock Chert Sedimentary
Original rock :Siliceous rock
Metamorphic facies :Greenschist
Wall rock Grønnstein Extrusive
Original rock :Basalt
Metamorphic facies :Greenschist

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Mineral banding Strike/Dip :38 / 90 Post-mineralisation ;...Effect :Modifies
Wall rock Foliation Strike/Dip :35 / 30 Post-mineralisation ;...Effect :Modifies

Information(s) in free text format
Free text
Forekomsten omfatter flere blotninger i området sør for Borvatnet, ca. 500 m til den sentrale delen av feltet. Området er relativt oversiktlig, men dårlig blottet. Magnetittbåndet vasskis opptrer i en rekke blotninger over en strøklengde på nesten en kilometer. Mektigheten kan gå opp i 2 meter. I enkelte blotninger finnes kun magnetitt. I tilleg finnes magnetitt-svovelkis og magnetitt-epidot båndet mineralisering. Bånding i mm- og cm-skala. Oftedahl melder om andre registreringer av magnetitt i nærheten, både små skjerp og geofysiske anomalier. Forekomsten ble oppdaget i 1918 av J. Marsfjell.

Bibliography:
From NGU's Reference Archive:
Oftedahl, Christoffer , 1958
Oversikt over Grongfeltets skjerp og malmforekomster.
;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.202;1-75 + fo pages
Abstract:
Ore occurences of the Grong area: In the period 1910-1918 a great number of ore occurences were discovered in the Grong area. The late state geologist Steinar Foslie mapped the area in the years 1922-1931. Foslie also mapped all claims and occurences and made special field investigations in a few cases. This book presents a survey of all occurences chiefly based on the field observations of Foslie. In addition the present author has done some field work in connection with the three large deposits, Joma, Skorovass, and Gjersvik. The map, Plate 1, shows the areal geology and the location of the occurrences, numbered from 1 to 131. the ore of the occurrences is chiefly pyrite. The larger occurrences also contain some chalcopyrite and sphalerite etc. and the smaller occurrences contain ither pure pyrite with some magnetite. The Joma deposit (No. 1), contains about 15.5 mill. tons of ore. The ore zone forms an arc and is situated within a thick series of greenstones (Fig. 1). The Skorovass mine (No. 2), contains about 7,5 mill. tons of ore. The deposit is situated in a greenstone complex (Fig. 7), and is immediately surrounded by asid tuffs of quartz keratophyric composition (Table 1).

Fieldsamples
Sample No. Sample type Miscellanrous
NT0318.01 Bedrock
Sampler: Sandstad, J.S./...Size(kg): 2
Comment: mt-malm, fink., massiv, homogen
No. of registrated element analyses = 1
NT0318.02 Bedrock
Sampler: Sandstad, J.S./...Size(kg): 2
Comment: py-malm, massiv, fin-middelsk., få smale kvarts/chert linser
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: 487 37,01,00)
Location
County: Trøndelag Municipality: Raarvihke (5043)
Map 1:50000: Jomafjellet (1924-1) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 439906 m. North: 7188278 m.
Longitude: 13.7344170 Latitude: 64.8135760
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:


Fieldsamples
Sample No. Sample type Miscellanrous
NT0318.03 Bedrock
Sampler: Sandstad, J.S./...Size(kg): 2
Comment: mt-py malm, båndet, fink., bånd i mm- og cm-skala (tipp)
No. of registrated element analyses = 1
NT0318.04 Bedrock
Sampler: Sandstad, J.S./...Size(kg): 2
Comment: mt-ep malm, fink., båndet, lyse grønne epidot-rike bånd
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Skjerp 2
(Object Id: 489 37,02,00)
Location
County: Trøndelag Municipality: Raarvihke (5043)
Map 1:50000: Jomafjellet (1924-1) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 439621 m. North: 7187928 m.
Longitude: 13.7285650 Latitude: 64.8103850
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:


Fieldsamples
Sample No. Sample type Miscellanrous
NT0318.05 Bedrock
Sampler: Sandstad, J.S./...Size(kg): 2
Comment: mt-malm, massiv, fink, årer med py-ep-kv.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: Skjerp 3
(Object Id: 488 37,03,00)
Location
County: Trøndelag Municipality: Raarvihke (5043)
Map 1:50000: Jomafjellet (1924-1) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 439571 m. North: 7187738 m.
Longitude: 13.7275930 Latitude: 64.8086720
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:


Fieldsamples
Sample No. Sample type Miscellanrous
LS91113 Bedrock
Sampler: Størseth, L.R.
Comment: Vasskis.
No. of registrated element analyses = 1
LS91114 Bedrock
Sampler: Størseth, L.R.
Comment: Epidotåret py-mt-malm.
No. of registrated element analyses = 1
NT0318.06 Bedrock
Sampler: Sandstad, J.S./...Size(kg): 2
Comment: py-malm, massiv, fink., få chert-/kvartslinser
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Analyse Results
from
Deposit Area 5043 - 037 Borvatnet

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#
LS91113 Bedrock 245 452 22 16 44 1.1 125.0
LS91114 Bedrock 168 125 9 28 63 .6 72.0
NT0318.01 Bedrock 93 117 -3 27 78 -.3 -1.0
NT0318.02 Bedrock 129 16 12 18 49 .4 63.0
NT0318.03 Bedrock 42 114 11 45 91 -.3 32.0
NT0318.04 Bedrock 7 43 8 19 37 -.3 39.0
NT0318.05 Bedrock 83 48 -3 28 53 -.3 2.0
NT0318.06 Bedrock 31 5 16 17 46 -.3 27.0
------------------
Sample No. Pt# Pd# Rh# As* Cd* Ba* Mo* Sb* Bi*
LS91113 2.0 2.0 26 .9 2 6.00 2 3
LS91114 4.0 5.0 2 .5 3 2.00 2 2
NT0318.01 4.0 6.0 -1.0 25 -.2 2 -1.00 -2 -2
NT0318.02 3.0 3.0 3.0 92 .2 9 1.00 -2 -2
NT0318.03 2.0 1.0 -1.0 12 .8 6 5.00 2 -2
NT0318.04 5.0 4.0 -1.0 46 -.2 4 -1.00 -2 -2
NT0318.05 3.0 4.0 -1.0 11 -.2 5 -1.00 2 3
NT0318.06 1.0 3.0 -1.0 70 -.2 8 4.00 -2 -2
------------------
Sample No. S% V* Cr* Mn* Fe% Th* U* W* Sr*
LS91113 32.97 5 39 109 19.29 1.00 5.00 1 26.0
LS91114 12.11 101 34 823 25.85 3.00 5.00 1 57.0
NT0318.01 -.01 132 52 3812 33.50 10.00 -5.00 -2 16.0
NT0318.02 32.82 12 13 130 21.30 3.00 -5.00 -2 11.0
NT0318.03 10.49 77 62 2635 22.13 6.00 -5.00 -2 19.0
NT0318.04 -.01 266 40 7145 28.91 17.00 -5.00 -2 65.0
NT0318.05 .72 143 49 2075 33.31 5.00 6.00 -2 30.0
NT0318.06 27.89 21 18 218 21.66 2.00 -5.00 -2 4.0
------------------
Sample No. La* B*
LS91113 2.00 7
LS91114 7.00 4
NT0318.01 14.00 -3
NT0318.02 2.00 7
NT0318.03 8.00 5
NT0318.04 7.00 -3
NT0318.05 10.00 6
NT0318.06 2.00 11

The fact sheet was created on 29.04.2024
Questions or comments regarding the fact sheet can be emailed to:
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