Fact Sheet for <b>Occurence 4630

					Norsk versjon
	THE ORE DATABASE
	Occurence 4630 - 007 Njåstad
	(Object Id: 4815) (Last updated: 29.01.2025)

Location

County:

Vestland

Municipality:

Osterøy (4630)

Map 1:50000:

Stanghelle (1216-3)

Map 1:250000:

Bergen

Coordinate system:

EU89-UTM Zone 32

East:

312135 m.

North:

6715488 m.

Longitude:

5.5758120

Latitude:

60.5314450

Show on map

Resource

	Resource Type:	Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn)	Resource Subtype:	Zinc
			Element(s):	Zn Cu

Importance

Raw material meaning:

Little Importance (reg. 18.02.2015)

Resources and production

	Activity:	Pitting	Reserves:
	Operating method:		Historical production:

Mineralization

Era: Proterozoic Period: Mesoproterozoic

Genesis: Volcex Form: Irregular

Main texture: Structureless Min. distribution: Disseminated (<20 % ore minerals)

Main grain size: Medium grained (1-3 mm) Main alteration:

Strike/Dip: Direction:

Plunge:

Stratigraphic classification of host rock

Era: Proterozoic Period: Mesoproterozoic

Province: Caledonian Basement Province

Geotec.unit: Lindås Nappe Complex

Tectonic complex:

Igneous complex:

Group: Formation:

Mineralogy

Relationship Mineral Amount

Gangue mineral Amphibole Major mineral (>10%)

Gangue mineral Quartz Major mineral (>10%)

Ore mineral Pyrrhotite Major mineral (>10%)

Ore mineral Pyrite Subordinate mineral (1-10%)

Ore mineral Sphalerite Accessory mineral (<1%)

Ore mineral Chalcopyrite Accessory mineral (<1%)

Lithology:

Relationship Rock Origin

Host rock Amphibolite

Metamorphic facies :Amphibolite

Structures

Location: Type: Orientation(360 gr.): Relation to min.:

Host rock Foliation Strike/Dip :160 / 80 Post-mineralisation ;...Effect :Controls

Information(s) in free text format

Free text

Det er to små skjerp i den bratte skrenten rett ovenfor gården Njåstad. Hovedskjerpet er et 3 m langt, 2m bredt og 4 m høyt innhugg. ca. 25 m mot nord i samme skrenten er det et 1x1 m innhugg. Mineralisering i veggen består av finkornet magnetkis med litt kobberkis og sinkblende i opptil cm-tykke slirer og årer (prøve 1). Sonen er omtrent 1 m mektig med svært varierende mengde sulfider. Nede under skrenten ble det funnet en blokk med finkornet sinkblende-pyrittmineralisering (prøve 2). Vertsbergart er en finkornet amfibolitt. Mineraliseringen ligger nær kontakten mellom Lindåsdekket og Hardangerfjorddekket.

Bibliography:

From NGU's Reference Archive:

Korneliussen, A.; Staw, J. ; Midthjell, B. , 1978

Befaringer av malmforekomster, Hordaland 1977.

;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.1560/17C;58 pages

Abstract:

For å høyne kunnskapsnivået og for dermed å bli bedre i stand til å plukke ut interessante forekomster og områder for nærmere undersøkelser, er det utført befaringer av malmforekomster i Hordaland sommeren 1977. 3 hovedområder har vært gjenstand for oppmerksomhet; Bergensmrådet (Fe, Ti, Cu, Ni-forekomster), Hardangerfjordområdet (Cu,Zn-forekomster) og Bømlo-området (Au, Cu-forekomster). Det gis en kort beskrivelse av de befarte forekomster, og en vurdering av de enkelte forekomster og av forekomsttyper og områder sett ut fra et økonomisk/malmgeologisk synspunkt.

Fieldsamples

Sample No. Sample type Miscellanrous

Njåstad-01 Bedrock

Sampler: Bjerkgård/Sandstad/...Stored: Løkken

Comment: Veinlets/dissemination of pyrrhotite-chalcopyrite in fine-/medium-grained amphibolite

No. of registrated element analyses = 1

Njåstad-02 Dump

Sampler: Bjerkgård/Sandstad/...Stored: Løkken

Comment: Massive, fine-grained pyrite-pyrrhotite-sphalerite in quartz-amphibole matrix

No. of registrated element analyses = 1

NB! All analyse values are shown at the end of the printout.:

Analyse Results

from

Deposit Area 4630 - 007 Njåstad

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#

Njåstad-01 Bedrock 3750 3950 36 48 39 2.5 5.0

Njåstad-02 Dump 107 35400 215 354 26 .5 6.0

------------------

Sample No. Pt# Pd# As* Cd* Ba* Mo* Sn* Sb* Bi*

Njåstad-01 -5.0 -1.0 2 9.4 40 1.58 5 0 0

Njåstad-02 -5.0 -1.0 14 94.8 -10 9.64 4 0 3

------------------

Sample No. Se* Ga* Ge* In* S% V* Cr* Mn* Fe%

Njåstad-01 6.00 18.90 0.14 0.39 5.83 343 121 1180 12.10

Njåstad-02 21.00 8.14 0.22 1.67 36.90 40 22 723 31.50

------------------

Sample No. Th* U* W* Rb* Sr* Y* Zr* Nb* Cs*

Njåstad-01 0.17 0.30 0 1.7 157.0 40.3 9 1.30 0.08

Njåstad-02 0.28 0.50 -0 0.6 36.6 4.9 4 0.30 -0.05

------------------

Sample No. La* Ce* Li* Be* P* Sc* Ti* Te* Hf*

Njåstad-01 3.70 12.75 9 0 670 39.30 7600 0.22 0.40

Njåstad-02 0.80 2.00 0 -0 90 4.20 1170 0.56 0.10

------------------

Sample No. Re* Tl*

Njåstad-01 0 0

Njåstad-02 0 0

Era:	Proterozoic	Period:	Mesoproterozoic
Genesis:	Volcex	Form:	Irregular
Main texture:	Structureless	Min. distribution:	Disseminated (<20 % ore minerals)

	Province:	Caledonian Basement Province
	Geotec.unit:	Lindås Nappe Complex
	Tectonic complex:
	Igneous complex:

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

Relationship	Rock	Origin
Host rock	Amphibolite
		Metamorphic facies :Amphibolite

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Foliation	Strike/Dip :160 / 80	Post-mineralisation ;...Effect :Controls

Sample No.	Sample Type	Cu*	Zn*	Pb*	Co*	Ni*	Ag*	Au#
Njåstad-01	Bedrock	3750	3950	36	48	39	2.5	5.0
Njåstad-02	Dump	107	35400	215	354	26	.5	6.0

Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sn*	Sb*	Bi*
Njåstad-01	-5.0	-1.0	2	9.4	40	1.58	5	0	0
Njåstad-02	-5.0	-1.0	14	94.8	-10	9.64	4	0	3

Sample No.	Se*	Ga*	Ge*	In*	S%	V*	Cr*	Mn*	Fe%
Njåstad-01	6.00	18.90	0.14	0.39	5.83	343	121	1180	12.10
Njåstad-02	21.00	8.14	0.22	1.67	36.90	40	22	723	31.50

Sample No.	Th*	U*	W*	Rb*	Sr*	Y*	Zr*	Nb*	Cs*
Njåstad-01	0.17	0.30	0	1.7	157.0	40.3	9	1.30	0.08
Njåstad-02	0.28	0.50	-0	0.6	36.6	4.9	4	0.30	-0.05

Sample No.	La*	Ce*	Li*	Be*	P*	Sc*	Ti*	Te*	Hf*
Njåstad-01	3.70	12.75	9	0	670	39.30	7600	0.22	0.40
Njåstad-02	0.80	2.00	0	-0	90	4.20	1170	0.56	0.10