Norsk versjon
THE ORE DATABASE
Occurence 5044 - 005 Øverste Nesåvatnet
(Object Id: 230)
(Last updated: 26.11.1998)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 408732 m. North: 7166449 m.
Longitude: 13.0920710 Latitude: 64.6107640
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Cu 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
1974 - 1974 Geophysics Company/Institution :Elkem A/S
1976 - 1976 Geology Company/Institution :Elkem A/S
1991 - 1991 Sampling Company/Institution :NGU
1995 - 1995 Inspection Company/Institution :NGU

Mineralization
Era: Paleozoic Period: Ordovician
Genesis: Volcex Form: Layer
Main texture: Structureless Min. distribution: Massive (>50 % ore minerals)
Main grain size: Fine grained (< 1 mm) Main alteration: Chloritisation
Strike/Dip: 22 / 20 Direction:
Plunge:
Stratigraphic classification of host rock
Era: Paleozoic Period:
Province: Caledonides
Geotec.unit: Køli Nappe Complex
Tectonic complex: Gjersvik Nappe
Igneous complex:
Group: Gjersvik Formation:

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

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

Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Primary layering Strike/Dip :22 / 20 Syn-mineralisation ;...Effect :Controls

Information(s) in free text format
Free text
En rekke skjerp ligger rundt det øverste Nesåvatnet, Drikkevatnet, 3-4 km rett syd for Skorovatn. I nordenden av øverste Nesåvatnet ligger skjerpene A-C, mens D-F ligger langs sørenden av det samme vannet. Terrenget er åpent, og mineraliseringene er lett å finne. Det største C, Finnkjerringhullet, er valgt som hovedforekomsten. Ved C er det gjort betydelig skjerping, og kraftig rustdannelse preger terrenget rundt. Skjerpene nord for vannet ligger langs tre tilnærmet parallelle, N-S orienterte elektriske ledere mens skjerpene sør for vannet er tilknyttet en tilnærmet Ø-V orientert sone med elektriske ledere. Finnkjerringhullet C, ligger i forlengelsen av Skorovass forekomsten mot sør. Det er flere skjerp på den samme sonen. Tilnærmet flattliggende, massiv pyritt-malm som er minst 1 m mektig ligger i grågrønn, andesittisk metabasalt som dels er klorittisert. Innholdet av basemetaller er lavt. A og B er et svært små skjerp. I A finnes svak sulfiddisseminasjon og pyritt i smale striper med lokal kobberanrikning i kvartskeratofyr.B er en typisk vasskis, med 10 cm mektig, massiv pyritt sammen jaspis. D,E og F ligger langs en tilnærmet sammenhengende ekshalitthorisont som består av pyritt, magnetitt og chert med varierende mengdeforhold. Chert er dels magnetittrik; blåkvartsitt. Lengst i øst dominerer magnetkis med spor av kobberkis. Sona er opptil flere titalls meter mektig og består da hovedsakelig av chert. Lagene med massiv pyritt eller massiv magnetitt er mindre enn 1 m mektige. Grønnstein opptrer på begge sider av ekshalitten, men den er i nær kontakt med felsisk vulkanitt i tektonostratigrafisk heng i vest.

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).

Singsaas, Per , 1975
Turammålinger Skorovas grubefelt.
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.1290;12 pages

Singsaas, Per , 1960
Geofysisk rekognosering Nesåvatn, Skorovas.
;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.245;3 pages

Fieldsamples
Sample No. Sample type Miscellanrous
LS91171 Bedrock
Sampler: Størseth, L.R.
Comment: Massive pyrite+chalcopyrite ore.
No. of registrated element analyses = 1
LS91172 Bedrock
Sampler: Størseth, L.R.
Comment: Pyrite-chalcopyrite grains i quartz vein.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: A
(Object Id: 462 5,01,00)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 409731 m. North: 7167039 m.
Longitude: 13.1125940 Latitude: 64.6163250
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Cu Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Fieldsamples
Sample No. Sample type Miscellanrous
JS95049 Bedrock
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Pyrite+sphalerite veins/bands in altered keratophyre.
No. of registrated element analyses = 1
LS91169 Bedrock
Sampler: Størseth, L.R.
Comment: Massive chalcopyrite rich pyritic ore.
No. of registrated element analyses = 1
LS91170 Bedrock
Sampler: Størseth, L.R.
Comment: Massive pyrite ore.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: B
(Object Id: 460 5,02,00)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 410082 m. North: 7166759 m.
Longitude: 13.1200810 Latitude: 64.6139070
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Fieldsamples
Sample No. Sample type Miscellanrous
AR95176 Dump
Sampler: Reinsbakken, A./...Stored: Løkken
Comment: Pyrite ore, massive, fine grained.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: D
(Object Id: 464 5,03,00)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 408192 m. North: 7165309 m.
Longitude: 13.0815100 Latitude: 64.6003950
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Fieldsamples
Sample No. Sample type Miscellanrous
JS95136 Block
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Massive pyrrhotite and semi-massive pyrite with chlorite-rich matrix.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: E
(Object Id: 461 5,04,00)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 408881 m. North: 7165449 m.
Longitude: 13.0958310 Latitude: 64.6018370
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Structures
Location: Type: Orientation(360 gr.): Relation to min.:
Host rock Foliation Strike/Dip :85 / 30 Post-mineralisation ;...Effect :Modifies

Information(s) in free text format
Free text
Vekslende lag med chert, dels magnetittførende ('blåkvarts'), massiv sulfid og massiv magnetitt finnes på begge sider av et mindre dalsøkk. Ekshalittsonen dominers av chert er tilsynelatende få titalls meter mektig

Fieldsamples
Sample No. Sample type Miscellanrous
JS95135 Bedrock
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Pyrite+pyrrhotite veins (cm scale) in white chert/altered felsic volcanite.
No. of registrated element analyses = 1
LS91173 Bedrock
Sampler: Størseth, L.R.
Comment: Banded fine grained pyrite ore ('vasskis').
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Sample point: E
(Object Id: 6831 5,04,01)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 408781 m. North: 7165359 m.
Longitude: 13.0937990 Latitude: 64.6010030
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Cu Kis


Fieldsamples
Sample No. Sample type Miscellanrous
JS95133 Bedrock
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Massive pyrite ore, fine grained, magnetite laminae.
No. of registrated element analyses = 1
JS95134 Bedrock
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Massive magnetite, fine grained, brownish black.
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Name of Locality: F
(Object Id: 463 5,05,00)
Location
County: Trøndelag Municipality: Namsskogan (5044)
Map 1:50000: Skorovatn (1824-2) Map 1:250000: Grong
Coordinate system: EU89-UTM Zone 33
East: 409481 m. North: 7165249 m.
Longitude: 13.1084860 Latitude: 64.6002040
Show on map
Resource
Resource Type: Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn) Resource Subtype: Copper
Element(s): Kis
Resources and production
Activity: Pitting Reserves:
Operating method: Historical production:


Information(s) in free text format
Free text
Det største skjerpet i området på sørsida av det Øverste Nesåvatnet finnes på et lite nes i østkanten av et mindre vann. Det består av en 2 mlang og 2 m høy skjæring i svært forvitra bergarter, men i skjerpet finnes mange blokker med massiv sulfid. Ekshalittsonen bestå i tillegg av fint båndet chert/blåkvarts, pyritt og magnetitt.

Fieldsamples
Sample No. Sample type Miscellanrous
JS95130 Bedrock
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Massive pyrrhotite, few chert lenses.
No. of registrated element analyses = 1
JS95131 Bedrock
Sampler: Sandstad, J.S/...Stored: Løkken
Comment: Pyrite aggregates in weathered, white chert.
No. of registrated element analyses = 1
JS95132 Bedrock
Sampler: Sandstad, J.S./...Stored: Løkken
Comment: Magnetite rich, dark bluish chert ('blue quartzite').
No. of registrated element analyses = 1
LS91174 Bedrock
Sampler: Størseth, L.R.
Comment: Fine grained, massive pyrite ore ('vasskis').
No. of registrated element analyses = 1
NB! All analyse values are shown at the end of the printout.:

Analyse Results
from
Deposit Area 5044 - 005 Øverste Nesåvatnet

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#
AR95176 Dump 347 260 27 7 26 .7 67.0
JS95049 Bedrock 465 1878 22 40 8 3.3 82.0
JS95130 Bedrock 434 1359 34 -1 95 -.3 10.0
JS95131 Bedrock 51 18 -3 3 7 -.3 -2.0
JS95132 Bedrock 32 5 3 -1 5 -.3 6.0
JS95133 Bedrock 148 123 39 1 36 .7 61.0
JS95134 Bedrock 99 208 -3 1 24 .5 4.0
JS95135 Bedrock 64 39 18 2 27 1.6 109.0
JS95136 Block 256 207 12 31 65 .6 49.0
LS91169 Bedrock 99999 869 25 438 7 21.3 331.0
LS91170 Bedrock 9002 94 33 152 7 2.0 86.0
LS91171 Bedrock 5578 1486 156 23 6 1.8 146.0
LS91172 Bedrock 939 540 6 12 14 .3 6.0
LS91173 Bedrock 419 395 82 6 35 .9 42.0
LS91174 Bedrock 134 55 24 8 48 .8 61.0
------------------
Sample No. Pt# Pd# As* Cd* Ba* Mo* Sb* Bi* S%
AR95176 3.0 -3.0 142 2.5 5 2.00 5 -2 32.79
JS95049 -3.0 -3.0 187 2.8 7 9.00 7 -2 14.90
JS95130 -3.0 -3.0 43 4.5 5 4.00 10 -2 31.27
JS95131 -3.0 -3.0 43 -.2 2 5.00 3 3 2.10
JS95132 -3.0 -3.0 223 -.2 3 4.00 2 -2 3.43
JS95133 -3.0 -3.0 143 1.2 4 7.00 2 -2 27.06
JS95134 10.0 6.0 17 1.2 119 -1.00 -2 -2 .75
JS95135 -3.0 -3.0 110 .2 5 24.00 5 -2 19.82
JS95136 -3.0 4.0 40 1.3 9 9.00 -2 -2 29.66
LS91169 1.0 1.0 166 14.4 3 1.00 2 3 31.34
LS91170 1.0 1.0 83 .3 2 1.00 2 21 34.66
LS91171 1.0 2.0 137 2.6 6 3.00 9 7 37.10
LS91172 1.0 2.0 11 1.3 4 4.00 2 2 1.48
LS91173 1.0 5.0 128 1.6 4 1.00 2 2 37.20
LS91174 5.0 7.0 102 .4 6 9.00 5 2 31.34
------------------
Sample No. V* Cr* Mn* Fe% Th* U* W* Sr* La*
AR95176 69 21 1733 25.65 2.00 5.00 -2 3.0 5.00
JS95049 40 5 753 18.75 -2.00 -5.00 -2 -1.0 1.00
JS95130 15 7 120 43.04 2.00 6.00 -2 5.0 5.00
JS95131 10 5 59 3.44 -2.00 -5.00 -2 5.0 -1.00
JS95132 4 5 52 6.18 -2.00 -5.00 -2 5.0 1.00
JS95133 64 12 2700 25.55 -2.00 -5.00 -2 9.0 3.00
JS95134 87 21 6312 26.10 2.00 -5.00 -2 46.0 20.00
JS95135 78 15 613 22.43 -2.00 -5.00 -2 14.0 1.00
JS95136 78 17 610 39.61 2.00 7.00 -2 21.0 2.00
LS91169 53 37 365 38.31 1.00 5.00 2 1.0 2.00
LS91170 68 19 622 34.49 1.00 5.00 1 1.0 2.00
LS91171 19 28 381 22.09 1.00 5.00 1 23.0 2.00
LS91172 10 18 413 2.73 1.00 5.00 1 15.0 2.00
LS91173 74 30 388 22.47 2.00 5.00 1 2.0 2.00
LS91174 56 24 972 31.67 1.00 5.00 1 3.0 2.00
------------------
Sample No. B*
AR95176 3
JS95049 3
JS95130 -3
JS95131 -3
JS95132 3
JS95133 -3
JS95134 -3
JS95135 -3
JS95136 -3
LS91169 5
LS91170 5
LS91171 3
LS91172 2
LS91173 3
LS91174 6

The fact sheet was created on 05.05.2024
Questions or comments regarding the fact sheet can be emailed to:
ressursdatabaser@ngu.no
Copyright © 2024 Geological Survey of Norway